Cement clinker manufacturing method and cement clinker manufacturing device

Abstract

When ammonia is supplied to a calciner in addition to pulverized coal and plastics, the generation of carbon monoxide due to incomplete combustion of solids is suppressed. [Solution] A method for manufacturing cement clinker, comprising: a first supply step of supplying pulverized coal to the inside of a calciner using one or more first supply members; a second supply step of supplying ammonia to the inside of the calciner using one or more second supply members; and a third supply step of supplying plastic to the inside of the calciner using one or more third supply members, wherein, based on the gas flow inside the calciner, the position at which the one or more second supply members supply ammonia is located upstream of the position at which the one or more first supply members supply the pulverized coal, and of the total calorific value of the thermal energy sources supplied to the inside of the calciner, the calorific value of the ammonia is 5% to 30%, the calorific value of the pulverized coal is 5% to 40%, and the calorific value of the plastic is 5% to 60%.

Description

[Technical Field]

[0001] The present disclosure relates to a method for producing cement clinker and an apparatus for producing cement clinker. [Background technology]

[0002] Patent Document 1 discloses a method for producing cement clinker using an NSP kiln equipped with a calciner and a rotary kiln. This method includes an introduction step of introducing a thermal energy raw material containing ammonia gas through a first inlet provided in the calciner, and a combustion step of burning the ammonia gas in the calciner. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2023-28050 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a method for producing cement clinker and an apparatus for producing cement clinker that are useful for suppressing the generation of carbon monoxide due to incomplete combustion of solids when ammonia is supplied to a calciner in addition to pulverized coal and plastics. [Means for solving the problem]

[0005] [1] A method for producing cement clinker, comprising: a first supplying step of supplying pulverized coal by one or more first supply members to the interior of a calciner into which exhaust gas from a rotary kiln that heats cement raw materials to produce cement clinker is introduced; a second supplying step of supplying ammonia by one or more second supply members to the interior of the calciner; and a third supplying step of supplying plastic by one or more third supply members to the interior of the calciner, wherein, based on the gas flow inside the calciner, a position from which the one or more second supply members supply the ammonia is located upstream of a position from which the one or more first supply members supply the pulverized coal, and of the total calorific values ​​of the thermal energy sources supplied to the interior of the calciner from the one or more first supply members, the one or more second supply members, and the one or more third supply members, the calorific value of the ammonia is 5% to 30%, the calorific value of the pulverized coal is 5% to 40%, and the calorific value of the plastic is 5% to 60%.

[0006] [2] The method for producing cement clinker according to the above [1], wherein in the second supplying step, the ammonia is supplied to the inside of the calciner together with air having an air ratio of 0.1 to 1.0.

[0007] [3] The method for producing cement clinker according to [1] or [2] above, wherein the proximate analysis values ​​of the plastic on arrival are: volatile matter 35 to 55 mass%, moisture 25 to 45 mass%, fixed carbon 1 to 10 mass%, and ash 10 to 25 mass%, and the chemical analysis values ​​of the plastic on arrival are: C (carbon) 25 to 45 mass%, H (hydrogen) 3 to 6 mass%, O (oxygen) 5 to 20 mass%, N (nitrogen) 0.5 to 2 mass%, and S (sulfur) 0.01 to 0.1 mass%, and the calorific value of the plastic is 2000 to 4500 kcal / kg.

[0008] [4] A method for producing cement clinker according to any one of [1] to [3] above, wherein the particle size distribution of the plastic calculated in terms of equivalent sphere diameter is such that particles having a diameter of 0.294 mm or less comprise 10 to 35 mass %, particles having a diameter of more than 0.294 mm and not more than 0.467 mm comprise 40 to 60 mass %, and particles having a diameter of more than 0.467 mm and not more than 0.741 mm comprise 15 to 40 mass %.

[0009] [5] The method for producing cement clinker according to any one of [1] to [4] above, wherein the pulverized coal has proximate analysis values, on an air-dry basis, of a volatile matter of 25 to 35 mass%, a moisture content of 2 to 4 mass%, a fixed carbon content of 40 to 60 mass%, and an ash content of 10 to 25 mass%, and has chemical analysis values, on an air-dry basis, of C (carbon) of 60 to 75 mass%, H (hydrogen) of 3 to 5 mass%, O (oxygen) of 6 to 9 mass%, N (nitrogen) of 1 to 3 mass%, and S (sulfur) of 0.1 to 1.0 mass%, and the calorific value of the pulverized coal is 4500 to 6500 kcal / kg.

[0010] [6] The method for producing cement clinker according to any one of [1] to [5] above, wherein the particle size distribution of the pulverized coal is such that particles having a particle size of 8.00 μm or more and less than 16.00 μm account for 5 to 20 mass %, particles having a particle size of 16.00 μm or more and less than 32.00 μm account for 20 to 40 mass %, particles having a particle size of 32.00 μm or more and less than 64.00 μm account for 20 to 40 mass %, and particles having a particle size of 64.00 μm or more and less than 128.00 μm account for 10 to 30 mass %.

[0011] [7] The method for producing cement clinker according to any one of [1] to [6] above, further comprising a fourth supplying step of supplying a hot gas containing oxygen to the inside of the calciner by one or more fourth supplying members, wherein the temperature of the hot gas is 700°C to 1000°C, and the positions to which the one or more fourth supplying members supply the hot gas, based on the gas flow inside the calciner, correspond to the positions to which the one or more first supplying members supply the pulverized coal, or are arranged upstream of the supplying positions, and are arranged downstream of the position to which the one or more second supplying members supply the ammonia.

[0012] [8] The method for producing cement clinker according to [7] above, wherein in the fourth supply step, extracted gas from a clinker cooler that cools the cement clinker produced in the rotary kiln is supplied as the hot gas.

[0013] [9] An apparatus for producing cement clinker, comprising: a rotary kiln that heats cement raw materials to produce cement clinker; a calciner into which exhaust gas from the rotary kiln is introduced and which heats the cement raw materials; one or more first supply members that supply pulverized coal to the interior of the calciner; one or more second supply members that supply ammonia to the interior of the calciner; and one or more third supply members that supply plastics to the interior of the calciner, wherein, based on the gas flow inside the calciner, the position at which the one or more second supply members supply the ammonia is located upstream of the position at which the one or more first supply members supply the pulverized coal; and of the total calorific values ​​of the thermal energy sources supplied to the interior of the calciner from the one or more first supply members, the one or more second supply members, and the one or more third supply members, the calorific value of the ammonia is 5% to 30%, the calorific value of the pulverized coal is 5% to 40%, and the calorific value of the plastic is 5% to 60%. [Effects of the Invention]

[0014] According to the present disclosure, there are provided a method for producing cement clinker and an apparatus for producing cement clinker that are useful for suppressing the generation of carbon monoxide due to incomplete combustion of solids when ammonia is supplied to a calciner in addition to pulverized coal and plastics. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a schematic diagram showing an example of a cement clinker manufacturing apparatus. [Figure 2] FIG. 2 is a schematic diagram showing an example of a calciner and its peripheral members. [Figure 3] FIG. 3 is a schematic diagram showing an example of a supply member for supplying pulverized coal and ammonia. [Figure 4] FIG. 4 shows an example of a supply member for supplying plastic. [Figure 5] FIG. 5 is a diagram illustrating a simulation result according to a reference example. [Figure 6] FIG. 6 is a diagram illustrating a simulation result according to the embodiment. [Figure 7] FIG. 7 is a diagram illustrating a simulation result according to the embodiment. [Figure 8] FIG. 8 is a diagram illustrating a simulation result according to the comparative example. [Figure 9] FIG. 9 is a diagram illustrating a simulation result according to the comparative example. [Figure 10] FIG. 10 is a graph illustrating the simulation results. [Figure 11] FIG. 11 is a graph illustrating the simulation results. DETAILED DESCRIPTION OF THE INVENTION

[0016] An embodiment will be described below with reference to the drawings. In the description, identical elements or elements having the same functions are designated by the same reference numerals, and redundant description will be omitted. The following embodiment is an example for explaining the present disclosure, and is not intended to limit the present disclosure to the following content. Furthermore, the dimensional ratios of each element are not limited to those shown in the drawings.

[0017] [Cement clinker manufacturing equipment] FIG. 1 schematically shows a cement clinker manufacturing apparatus according to one embodiment. The manufacturing apparatus 100 (cement clinker manufacturing apparatus) shown in FIG. 1 is an apparatus that manufactures cement clinker, an intermediate cement product, by burning cement raw materials. The manufacturing apparatus 100 is equipped with a preheating device of the NSP (New Suspension Preheater) type. The manufacturing apparatus 100 is also referred to as an NSP kiln. The manufacturing apparatus 100 includes, for example, cyclones C1, C2, C3, and C4, a calciner 30, a rotary kiln 40, and a clinker cooler 48.

[0018] Cyclones C1, C2, C3, and C4 and the calciner 30 function as preheaters that preheat and calcinate the cement raw materials. The cement raw materials may include, for example, two or more selected from the group consisting of incineration ash, coal ash, limestone, an iron source, and slag. The cement raw materials are introduced from the connection between cyclones C1 and C2, heated while flowing through cyclones C1, C2, C3, the calciner 30, and C4, and introduced into the kiln end 42 of the rotary kiln 40. When introduced into the kiln end 42 of the rotary kiln 40, the cement raw materials are heated to, for example, 850°C to 1000°C, preferably 850°C to 900°C.

[0019] The calciner 30 and the kiln end 42 of the rotary kiln 40 are connected by a rising duct 34. Exhaust gas from the rotary kiln 40 is introduced into the calciner 30 via the rising duct 34. The exhaust gas generated in the rotary kiln 40 includes combustion exhaust gas. The exhaust gas from the rotary kiln 40 flows through the calciner 30, cyclone C4, cyclone C3, cyclone C2, and cyclone C1, and heat exchange occurs between the exhaust gas and the cement raw materials.

[0020] The calciner 30 calcines the cement raw materials using exhaust gas from the rotary kiln 40 and a thermal energy source supplied to the calciner 30. In other words, the calciner 30 is a heating furnace that heats the cement raw materials. At least a portion of the calciner 30 is cylindrical (see also FIG. 2). In at least a portion of the calciner 30, the sidewall of the calciner 30 may extend around the central axis of the calciner 30. The central axis of the calciner 30 is an imaginary line, for example, a line extending in the vertical direction.

[0021] A probe 36 is connected to the rising duct 34, which extracts the exhaust gas from the rising duct 34. A chlorine bypass system having a cooler, a bag filter, etc. is installed downstream of the probe 36, and dust contained in the extracted gas (exhaust gas) extracted by the probe 36 is recovered. By installing the chlorine bypass system, volatile matters such as chlorine compounds and alkalis can be reduced from within the manufacturing apparatus 100. The probe 36 may be connected to the kiln end 42 instead of the rising duct 34, or may be connected to the boundary between the rising duct 34 and the kiln end 42.

[0022] The rotary kiln 40 burns cement raw materials to produce cement clinker (hereinafter, sometimes simply referred to as "clinker"). In other words, the rotary kiln 40 is a heating furnace that heats the cement raw materials. The rotary kiln 40 is equipped with a burner 44 that burns fuel. The burner 44 is disposed at the downstream end of the rotary kiln 40 (the end close to the clinker cooler 48). The cement raw materials are heated in the rotary kiln 40 to, for example, 1300°C to 1450°C by combustion in the burner 44. In the rotary kiln 40, the cement raw materials that have been preheated and calcined are heated by combustion in the burner 44 to become clinker.

[0023] The clinker produced in the rotary kiln 40 is discharged to the clinker cooler 48. The clinker cooler 48 cools the clinker with cooling air such as outside air. The clinker cooled in the clinker cooler 48 is discharged from the manufacturing apparatus 100. A portion of the gas used to cool the clinker in the clinker cooler 48 may be introduced into the calciner 30 as bleed gas. The temperature of the bleed gas introduced from the clinker cooler 48 into the calciner 30 may be 700°C to 1000°C, or 800°C to 900°C. The introduction of a thermal energy source into the calciner 30 will be described below.

[0024] <Introduction of thermal energy source> FIG. 2 schematically shows a portion for introducing a thermal energy source into the calciner 30. The manufacturing apparatus 100 includes a thermal energy source supply unit 50. The thermal energy source supply unit 50 supplies three or more types of thermal energy sources. In order to reduce carbon dioxide emissions, ammonia (ammonia gas) is introduced into the calciner 30 as one type of thermal energy source. In addition to the calciner 30, ammonia (ammonia gas) may be introduced into the rotary kiln 40 as one type of thermal energy source. In the calciner 30, ammonia gas is combusted. In FIG. 2 and other figures, the "Z" axis direction represents the vertical direction, and "S" represents the internal space of the calciner 30.

[0025] (First supply element: pulverized coal) The thermal energy source supply unit 50 has one or more supply members 60 (first supply members). In the example shown in FIG. 2, two supply members 60 are provided. The supply members 60 are members (burners) that supply pulverized coal as a type of thermal energy source to the inside of the calciner 30. The two supply members 60 supply pulverized coal to the inside of the calciner 30 from different positions. The pulverized coal is a solid thermal energy source. The supply members 60 may supply pulverized coal and combustion air to the inside of the calciner 30.

[0026] An inlet 62 is provided at an end of the supply member 60, through which pulverized coal and combustion air are discharged (blowed) into the interior of the calciner 30 (see FIG. 3). The end of the supply member 60 including the inlet 62 functions as a nozzle. The end of the supply member 60 that functions as a nozzle may be installed horizontally. FIG. 3 schematically shows an enlarged view of the portion marked III in FIG. 2. As shown in FIG. 3, the end of the supply member 60 may be connected to a side wall of the calciner 30.

[0027] The supply member 60 may transport the pulverized coal to its inlet 62 by carrier air. The supply member 60 may separately supply the pulverized coal (pulverized coal and carrier air) and combustion air to the inside of the calciner 30. The combustion air may be discharged as a swirling flow from the inlet 62. The inlet 62 at the end of the supply member 60 may include one or more openings for discharging the pulverized coal and one or more openings for discharging the combustion air. In this case, the pulverized coal and the combustion air are discharged into the inside of the calciner 30 without joining together inside the supply member 60.

[0028] In the example shown in Figures 2 and 3, one of the two supply members 60 is referred to as the "supply member 60a" and the other is referred to as the "supply member 60b." The supply members 60a and 60b have similar functions and configurations. In the direction of gas flow inside the calciner 30, at least a portion of the inlet 62 of the supply member 60a is disposed in the same position as at least a portion of the inlet 62 of the supply member 60b. The direction of gas flow inside the calciner 30 (hereinafter referred to as the "gas flow direction F") is defined as the direction from the inlet 30a, through which exhaust gas from the rotary kiln 40 of the calciner 30 is introduced, to the outlet 30b, through which combustion gas containing that exhaust gas is discharged.

[0029] In the examples shown in FIGS. 2 and 3, the gas flow direction F is a vertical direction from bottom to top. Inside the calciner 30, combustion gas, including exhaust gas from the rotary kiln 40, may circulate while swirling. The gas flow direction F is defined by the relative positions of the exhaust gas inlet 30a and the combustion gas outlet 30b. The height position of at least a portion of the inlet 62 of the supply member 60a may coincide with the height position of at least a portion of the inlet 62 of the supply member 60b. In a plan view (viewed vertically from above), the inlet 62 of the supply member 60a and the inlet 62 of the supply member 60b are positioned differently in the circumferential direction around the central axis of the calciner 30. In one example, the angle (the smaller angle of deviation) between the inlet 62 of the supply member 60a and the inlet 62 of the supply member 60b in the circumferential direction may be approximately 150° to 180°, approximately 160° to 180°, or approximately 170° to 180°. The position of the inlet 62 in the circumferential direction in a plan view is defined by the center of the inlet 62.

[0030] In a plan view, the direction in which the end portions of the supply members 60 (each of the supply members 60a and 60b) that function as nozzles extend may be perpendicular to the side wall of the calciner 30. The direction in which the end portions of the supply members 60 extend may coincide with a direction perpendicular to the inlet 62. Alternatively, in a plan view, the direction in which the end portions of the supply members 60 extend may be inclined with respect to a direction perpendicular to the side wall of the calciner 30 (a radial direction of a circumference around the central axis of the calciner 30) so as to follow the swirling flow formed in the calciner 30. In one example, the angle at which the end portions are inclined with respect to a direction perpendicular to the side wall of the calciner 30 in a plan view may be approximately 10°, 20°, 30°, or 40°.

[0031] An example of the components, calorific value, and particle size distribution of the pulverized coal supplied from one or more supply members 60 will be described. The proximate analysis values ​​(mass %: air-dry basis) of the volatile matter, moisture, fixed carbon, and ash content of the pulverized coal may be in the following ranges. (a) The proximate analysis value of the volatile content may be 25% by mass or more, 26% by mass or more, 27% by mass or more, or 28% by mass or more. The proximate analysis value of the volatile content may be 35% by mass or less, 34% by mass or less, 33% by mass or less, or 32% by mass or less. In one example, the proximate analysis value of the volatile content is 25 to 35% by mass, or 28 to 32% by mass. (b) The proximate analysis value of the moisture content may be 2.0% by mass or more, 2.2% by mass or more, 2.4% by mass or more, or 2.6% by mass or more. The proximate analysis value of the moisture content may be 4.0% by mass or less, 3.8% by mass or less, 3.6% by mass or less, or 3.4% by mass or less. In one example, the proximate analysis value of the moisture content is 2.0 to 4.0% by mass, or 2.6% to 3.4% by mass. (c) The proximate analysis value of fixed carbon may be 40% by mass or more, 42% by mass or more, 44% by mass or more, or 46% by mass or more. The proximate analysis value of fixed carbon may be 60% by mass or less, 58% by mass or less, 56% by mass or less, or 54% by mass or less. In one example, the proximate analysis value of fixed carbon is 40 to 60% by mass, or 46 to 54% by mass. (d) The proximate analysis value of the ash content may be 10% by mass or more, 11% by mass or more, 12% by mass or more, or 13% by mass or more. The proximate analysis value of the ash content may be 25% by mass or less, 24% by mass or less, 23% by mass or less, or 22% by mass or less. In one example, the proximate analysis value of the ash content is 10 to 25% by mass, or 13 to 22% by mass.

[0032] In one example, the proximate analysis values ​​of the components of pulverized coal are 25 to 35 mass% for volatile matter, 2 to 4 mass% for moisture, 40 to 60 mass% for fixed carbon, and 10 to 25 mass% for ash. The proximate analysis values ​​of the components of pulverized coal are analytical values ​​measured by the test method described in JIS M8812 "Coals and cokes - Proximate analysis methods."

[0033] The chemical analysis values ​​(mass %: air-dry basis) of C (carbon), H (hydrogen), O (oxygen), N (nitrogen), and S (sulfur) of the pulverized coal may be in the following ranges. (a) The chemical analysis value of C may be 60% by mass or more, 61% by mass or more, 62% by mass or more, or 63% by mass or more. The chemical analysis value of C may be 75% by mass or less, 74% by mass or less, 73% by mass or less, or 72% by mass or less. In one example, the chemical analysis value of C is 60 to 75% by mass, or 63 to 72% by mass. (b) The chemical analysis value of H may be 3.0% by weight or more, 3.2% by weight or more, 3.4% by weight or more, or 3.6% by weight or more. The chemical analysis value of H may be 5.0% by weight or less, 4.8% by weight or less, 4.6% by weight or less, or 4.4% by weight or less. In one example, the chemical analysis value of H is 3-5% by weight, or 3.6-4.4% by weight. (c) The chemical analysis value of O may be 6.0% by weight or more, 6.2% by weight or more, 6.4% by weight or more, or 6.6% by weight or more. The chemical analysis value of O may be 9.0% by weight or less, 8.8% by weight or less, 8.6% by weight or less, or 8.4% by weight or less. In one example, the chemical analysis value of O is 6-9% by weight, or 6.6-8.4% by weight. (d) The chemical analysis value of N may be 1.0% by weight or more, 1.1% by weight or more, 1.2% by weight or more, or 1.3% by weight or more. The chemical analysis value of N may be 3.0% by weight or less, 2.8% by weight or less, 2.6% by weight or less, or 2.4% by weight or less. In one example, the chemical analysis value of N is 1-3% by weight, or 1.3-2.4% by weight. (e) The chemical analysis value of S may be 0.1% by weight or more, 0.2% by weight or more, 0.3% by weight or more, or 0.4% by weight or more. The chemical analysis value of S may be 1.0% by weight or less, 0.9% by weight or less, 0.8% by weight or less, or 0.7% by weight or less. In one example, the chemical analysis value of S is 0.1 to 1.0% by weight, or 0.4 to 0.7% by weight.

[0034] In one example, the chemical analysis values ​​(air-dry basis) of the components of the pulverized coal are 60 to 75 mass% C, 3 to 5 mass% H, 6 to 9 mass% O, 1 to 3 mass% N, and 0.1 to 1.0 mass% S. The chemical analysis values ​​(air-dry basis) of the components of the pulverized coal are analytical values ​​measured by the test methods described in JIS M8813 "Coals and cokes - Methods for elemental analysis" and JIS M8810 "Coals and cokes - General rules for sampling, analysis, and test methods."

[0035] The chemical analysis values ​​(mass %: dry and ash-free basis) of C, H, O, N, and S of the pulverized coal may be in the following ranges. (a) The chemical analysis value of C may be 75% by mass or more, 76% by mass or more, 77% by mass or more, or 78% by mass or more. The chemical analysis value of C may be 90% by mass or less, 89% by mass or less, 88% by mass or less, or 87% by mass or less. In one example, the chemical analysis value of C is 75 to 90% by mass, or 78 to 88% by mass. (b) The chemical analysis value of H may be 4.0% by weight or more, 4.2% by weight or more, 4.4% by weight or more, or 4.6% by weight or more. The chemical analysis value of H may be 6.0% by weight or less, 5.8% by weight or less, 5.6% by weight or less, or 5.4% by weight or less. In one example, the chemical analysis value of H is 4-6% by weight, or 4.6-5.4% by weight. (c) The chemical analysis value of O may be 8.0% by weight or more, 8.2% by weight or more, 8.4% by weight or more, or 8.6% by weight or more. The chemical analysis value of O may be 11.0% by weight or less, 10.8% by weight or less, 10.6% by weight or less, or 10.4% by weight or less. In one example, the chemical analysis value of O is 8 to 11% by weight, or 8.6 to 10.4% by weight. (d) The chemical analysis value of N may be 1.0% by weight or more, 1.1% by weight or more, 1.2% by weight or more, or 1.3% by weight or more. The chemical analysis value of N may be 3.0% by weight or less, 2.9% by weight or less, 2.8% by weight or less, or 2.7% by weight or less. In one example, the chemical analysis value of N is 1-3% by weight, or 1.3-2.7% by weight. (e) The chemical analysis value of S may be 0.1% by weight or more, 0.2% by weight or more, 0.3% by weight or more, or 0.4% by weight or more. The chemical analysis value of S may be 1.0% by weight or less, 0.9% by weight or less, 0.8% by weight or less, or 0.7% by weight or less. In one example, the chemical analysis value of S is 0.1 to 1.0% by weight, or 0.4 to 0.7% by weight.

[0036] In one example, the chemical analysis values ​​(on an anhydrous ash-free basis) of the components of pulverized coal are 75 to 90 mass% C, 4 to 6 mass% H, 8 to 11 mass% O, 1 to 3 mass% N, and 0.1 to 1.0 mass% S. The chemical analysis values ​​(on an air-dry basis) of the components of pulverized coal are analytical values ​​measured by the test methods described in JIS M8813 "Coals and cokes - Methods for elemental analysis" and JIS M8810 "Coals and cokes - General rules for sampling, analysis, and test methods."

[0037] The calorific value of the pulverized coal (more specifically, the lower heating value of the pulverized coal on arrival) may be 4500 kcal / kg or more, 4700 kcal / kg or more, 4900 kcal / kg or more, or 5100 kcal / kg or more. In the present disclosure, the calorific value of the pulverized coal refers to the lower heating value (on arrival). The calorific value of the pulverized coal may be 6500 kcal / kg or less, 6300 kcal / kg or less, 6100 kcal / kg or less, or 5900 kcal / kg or less. In one example, the calorific value of the pulverized coal is 4500 to 6500 kcal / kg or 5100 to 5900 kcal / kg. The calorific value of the pulverized coal, i.e., the lower heating value (on arrival) of the pulverized coal, is measured by the test method described in JIS M8814, "Coals and cokes - Method for measuring gross calorific value using a bomb calorimeter and method for calculating net calorific value."

[0038] The particle size distribution of the pulverized coal (mass proportion for each particle size division) may be in the following ranges: The mass proportion (mass %) for each particle size division means the proportion of the mass of particles in that particle size division to the total mass of the pulverized coal. (a) Particles having a particle size of less than 8.00 μm may be 15% by mass or less, 13% by mass or less, 11% by mass or less, or 9% by mass or less. It is also possible that no particles having a particle size of less than 8.00 μm are contained. (b) The content of particles having a particle size of 8.00 μm or more and less than 16.00 μm may be 5% by mass or more, 6% by mass or more, 7% by mass or more, or 8% by mass or more. The content of particles having a particle size of 8.00 μm or more and less than 16.00 μm may be 20% by mass or less, 19% by mass or less, 18% by mass or less, or 17% by mass or less. In one example, the content of particles having a particle size of 8.00 μm or more and less than 16.00 μm is 5 to 20% by mass, or 8 to 17% by mass. (c) The content of particles having a particle size of 16.00 μm or more and less than 32.00 μm may be 20% by mass or more, 22% by mass or more, 24% by mass or more, or 26% by mass or more. The content of particles having a particle size of 16.00 μm or more and less than 32.00 μm may be 40% by mass or less, 38% by mass or less, 36% by mass or less, or 34% by mass or less. In one example, the content of particles having a particle size of 16.00 μm or more and less than 32.00 μm is 20 to 40% by mass, or 26 to 34% by mass. (d) The content of particles having a particle size of 32.00 μm or more and less than 64.00 μm may be 20% by mass or more, 22% by mass or more, 24% by mass or more, or 26% by mass or more. The content of particles having a particle size of 32.00 μm or more and less than 64.00 μm may be 40% by mass or less, 38% by mass or less, 36% by mass or less, or 34% by mass or less. In one example, the content of particles having a particle size of 32.00 μm or more and less than 64.00 μm is 20 to 40% by mass, or 26 to 34% by mass. (e) The content of particles having a particle size of 64.00 μm or more and less than 128.00 μm may be 10% by mass or more, 12% by mass or more, 14% by mass or more, or 16% by mass or more. The content of particles having a particle size of 64.00 μm or more and less than 128.00 μm may be 30% by mass or less, 28% by mass or less, 26% by mass or less, or 24% by mass or less. In one example, the content of particles having a particle size of 64.00 μm or more and less than 128.00 μm is 10 to 30% by mass, or 16 to 24% by mass. (f) Particles having a particle size of 128.00 μm or more may be 10% by mass or less, 9% by mass or less, 8% by mass or less, or 7% by mass or less. It is not necessary for particles having a particle size of 128.00 μm or more to be contained.

[0039] In one example, the particle size distribution of the pulverized coal is such that particles having a particle size of 8.00 μm or more and less than 16.00 μm account for 5 to 20 mass %, particles having a particle size of 16.00 μm or more and less than 32.00 μm account for 20 to 40 mass %, particles having a particle size of 32.00 μm or more and less than 64.00 μm account for 20 to 40 mass %, and particles having a particle size of 64.00 μm or more and less than 128.00 μm account for 10 to 30 mass %. In this case, the pulverized coal may contain at least one of particles having a particle size less than 8.00 μm and particles having a particle size of 128.00 μm or more, or may not contain both of these particles. The particle size distribution (particle size) of the pulverized coal is measured by the test method described in JIS Z 8825 "Particle Size Analysis - Laser Diffraction and Scattering Method."

[0040] (Second supply member: ammonia) The thermal energy source supply unit 50 has one or more supply members 70 (second supply members). In the example shown in FIG. 2, two supply members 70 are provided. The supply members 70 are members (burners) that supply ammonia as a type of thermal energy source to the inside of the calciner 30. The two supply members 70 supply ammonia to the inside of the calciner 30 from different positions. The supply members 70 are configured to supply an ammonia-containing gas containing ammonia. The ammonia-containing gas supplied by the supply member 70 may be ammonia gas alone, or may be a mixed gas of ammonia gas with other gases such as air or methane.

[0041] The supplying member 70 may supply ammonia together with combustion air to the inside of the calciner 30. In the supplying member 70, the ammonia and the combustion air may be merged before being introduced into the inside of the calciner 30, or the ammonia and the combustion air may be supplied separately without being merged. The air ratio of the combustion air supplied together with ammonia is, for example, 0.1 to 1.0. The air ratio is defined as the ratio of the amount of air actually supplied to the minimum amount of air required for theoretically completely combusting the ammonia supplied from the supplying member 70.

[0042] The air ratio of the combustion air from the supply member 70 may be 0.15 or more, 0.2 or more, or 0.25 or more, from the viewpoint of promoting the combustion of ammonia. The air ratio of the combustion air from the supply member 70 may be 0.9 or less, 0.8 or less, or 0.7 or less, from the viewpoint of efficiently introducing air. In one example, exhaust gas from the chlorine bypass facility is introduced as combustion air from each of the supply member 70 and the supply member 60.

[0043] The supply member 70 may supply the ammonia-containing gas continuously while the calciner 30 is operating, or may supply the ammonia-containing gas for part of the period while the calciner 30 is operating.

[0044] A part of the ammonia-containing gas supplied from the supply member 70 may be used as a thermal energy source, and another part may be used for denitration. That is, the reaction may occur not only as shown in the following formula (1) but also as shown in formula (2). NH3 + 1 / 4O2 → 1 / 2N2 + 3 / 2H2O (1) NH3 + NO + 1 / 4O2 → N2 + 3 / 2H2O (2) The calciner 30 has a temperature range in which both the combustion reaction and the denitration reaction can proceed, and therefore can perform both the ammonia combustion reaction and the denitration reaction, thereby reducing the emissions of both carbon dioxide and nitrogen oxides.

[0045] The ammonia contained in the ammonia-containing gas supplied from the supply member 70 may be used for both combustion and denitration in the calciner 30, or all or most of the ammonia from the supply member 70 may be used for the combustion reaction, and the ammonia used for the denitration reaction may be supplied from an inlet 20 located at a position separate from the supply member 70. The ammonia-containing gas supplied from the inlet 20 may contain only ammonia gas, or may be a mixed gas of ammonia gas and another gas. The inlet 20 is provided, for example, in a connection part 38 that connects the outlet 30b of the calciner 30 to the cyclone C4 and through which the exhaust gas from the calciner 30 flows.

[0046] An end of the supply member 70 is provided with an inlet 72 for discharging (blowing) the ammonia-containing gas into the interior of the calciner 30 (see FIG. 3 ). The end of the supply member 70 including the inlet 72 functions as a nozzle. The inlet 72 of the supply member 70 may be provided with one or more openings for introducing the ammonia-containing gas. The inlet 72 at the end of the supply member 70 may include one or more openings for discharging the combustion air in addition to one or more openings for discharging the ammonia-containing gas. A portion of the combustion air introduced together with the ammonia-containing gas may be discharged from the inlet 72 as a swirling flow, and another portion of the combustion air may be discharged from the inlet 72 without swirling (for example, in a straight line). The end of the supply member 70 functioning as a nozzle may be installed horizontally. As shown in FIG. 3 , the end of the supply member 70 may be connected to a side wall of the calciner 30.

[0047] In the example shown in FIGS. 2 and 3 , one of the two supply members 70 is referred to as the “supply member 70a,” and the other is referred to as the “supply member 70b.” The supply members 70a and 70b have similar functions and configurations. In the gas flow direction F within the calciner 30, at least a portion of the inlet 72 of the supply member 70a is disposed at the same position as at least a portion of the inlet 72 of the supply member 70b. When the gas flow direction F is along the vertical direction, the height position of at least a portion of the inlet 72 of the supply member 70a may coincide with the height position of at least a portion of the inlet 72 of the supply member 70b. In a plan view, the inlet 72 of the supply member 70a and the inlet 72 of the supply member 70b are positioned at different circumferential positions around the central axis of the calciner 30. In one example, the angle (the smaller angle of deviation) between the inlet 72 of the supply member 70a and the inlet 72 of the supply member 70b in the circumferential direction may be approximately 150° to 180°, approximately 160° to 180°, or approximately 170° to 180°. The position of the inlet 72 in the circumferential direction in a plan view is defined by the center of the inlet 72.

[0048] In a plan view, the direction in which the end portions of the supply members 70 (each of the supply members 70a and 70b) that function as nozzles extend may be perpendicular to the side wall of the calciner 30. The direction in which the end portions of the supply members 70 extend may coincide with a direction perpendicular to the inlet 72. Alternatively, in a plan view, the direction in which the end portions of the supply members 70 extend may be inclined with respect to a direction perpendicular to the side wall of the calciner 30 (a radial direction of a circumference around the central axis of the calciner 30) so as to follow the swirling flow formed in the calciner 30. In one example, the angle at which the end portions are inclined with respect to a direction perpendicular to the side wall of the calciner 30 in a plan view may be approximately 10°, 20°, 30°, or 40°.

[0049] (Positional relationship between the first supply member and the second supply member) The following describes the positional relationship between one or more supply members 60 and one or more supply members 70. In the following, the positional relationship between one supply member 60 and one supply member 70 is described, but the same positional relationship applies to all combinations of supply members 70 and 60.

[0050] The supply member 70 is formed separately from the supply member 60. That is, the supply member 70 is physically separated from the supply member 60. The supply member 70 discharges the ammonia-containing gas from a position different from the position from which the supply member 60 supplies the pulverized coal. That is, the position from which the supply member 60 supplies the pulverized coal to the inside of the calciner 30 and the position from which the supply member 70 supplies the ammonia-containing gas to the inside of the calciner 30 are different from each other. In the present disclosure, supplying (discharging) a thermal energy source from different positions (locations) means that two supply members formed separately each supply (discharge) a thermal energy source.

[0051] With respect to the gas flow direction F in the calciner 30 as a reference, the position at which the supplying member 70 supplies ammonia is disposed upstream of the position at which the supplying member 60 supplies pulverized coal. The position at which the supplying member 70 supplies ammonia corresponds to the position of an inlet 72 of the supplying member 70 that discharges ammonia (ammonia-containing gas), and hereinafter this position will be referred to as the "supply position of the supplying member 70." The position at which the supplying member 60 supplies pulverized coal corresponds to the position of an inlet 62 of the supplying member 60 that discharges pulverized coal, and hereinafter this position will be referred to as the "supply position of the supplying member 60." When the gas flow direction F is along the vertical direction, the uppermost position (the highest position) of the inlet 72 of the supplying member 70 is located below the lowermost position (the lowest position) of the inlet 62 of the supplying member 60.

[0052] As described above, (all of) the supply positions of one or more supply members 70 are disposed upstream of (all of) the supply positions of one or more supply members 60 in the gas flow direction F. When the gas flow direction F is along the vertical direction, (all of) the supply positions of one or more supply members 70 are disposed at a lower position than (all of) the supply positions of one or more supply members 60. In the example shown in FIG. 2, the supply position of supply member 70a is disposed at a lower position than both the supply position of supply member 60a and the supply position of supply member 60b. The supply position of supply member 70b is also disposed at a lower position than both the supply position of supply member 60a and the supply position of supply member 60b. In a plan view, the supply positions of supply member 60a and supply member 70a may be approximately aligned with each other, and the supply positions of supply member 60b and supply member 70b may be approximately aligned with each other. The supply position of the supply member 60a (supply member 60b) and the supply position of the supply member 70a (supply member 70b) may be different from each other in a plan view, as long as the combustion of ammonia or pulverized coal is not affected. In one example, the supply positions may be shifted by about 10°, 20°, or 30° in the circumferential direction around the central axis of the calciner 30 in a plan view.

[0053] There is a concern that the supply of ammonia into the calciner 30 will increase the concentration of carbon monoxide contained in the gas discharged from the calciner 30. The following two factors are thought to be factors that cause the increase in carbon monoxide concentration. (A) Inhibition of combustion of solid matter such as pulverized coal by combustion of ammonia (B) Reaction of ammonia with carbon dioxide

[0054] Regarding factor (A), it is believed that oxygen around the pulverized coal is consumed first by the combustion of ammonia gas, a combustible gas, resulting in a temporary shortage of oxygen for the combustion reaction of the pulverized coal. Generally, the combustion of solids involves the thermal decomposition of the solids into gas and char, which then combust separately. Therefore, it is presumed that the combustion rate of the combustible gas (ammonia gas) is faster than that of the solids. Consider the case where pulverized coal with a relatively slow combustion rate and ammonia gas with a relatively fast combustion rate are supplied from the same position in the gas flow direction F within the calciner 30, or the case where pulverized coal is supplied upstream and ammonia gas is supplied downstream. In these cases, due to the difference in combustion rate, oxygen is consumed around the ammonia gas supply position due to the combustion of ammonia gas, resulting in a temporary shortage of oxygen for burning the incompletely combusted pulverized coal around the pulverized coal supply position. This results in the promotion of carbon monoxide generation.

[0055] In contrast, in the manufacturing apparatus 100, ammonia gas is supplied upstream in the gas flow direction F by the supply member 70, and pulverized coal is supplied downstream by the supply member 60. In this case, the possibility of oxygen shortage around the pulverized coal supplied downstream due to combustion of ammonia gas can be reduced. It is also considered that the reaction between carbon dioxide generated by the combustion of pulverized coal and ammonia can be suppressed. Therefore, by supplying ammonia gas upstream and supplying pulverized coal downstream, it is possible to suppress an increase in carbon monoxide concentration due to ammonia gas.

[0056] (Third supply material: plastic) The thermal energy source supply unit 50 has one or more supply members 80 (third supply members). In the example shown in FIG. 2, three supply members 80 are provided. The supply members 80 are members (burners) that supply plastic as a type of thermal energy source to the inside of the calciner 30. The three supply members 80 supply plastic to the inside of the calciner 30 from different positions. The plastic is a solid thermal energy source. The plastic may be a hard plastic or a soft plastic.

[0057] Hard plastics are plastics that are thicker than a credit card and are products in themselves, rather than containers or packaging. Examples of such plastic products include storage cases, containers, buckets, home appliances, and car bodies. Hard plastics include polyethylene, polypropylene, polystyrene, polycarbonate, and acrylic butadiene styrene. Flexible plastics are flammable resins (general-purpose plastics) that can be easily reshaped and used in products such as packaging films, food trays, cable ties, plastic string, and candy bags. Flexible plastics include polyethylene, high-density polyethylene (HDPE), medium-density polyethylene (MDPE), low-density polyethylene (LDPE), polypropylene (PP), polystyrene (PS), polyvinyl acetate (PVAc), polyurethane (PUR), polylactic acid, Teflon (registered trademark: polytetrafluoroethylene, PTFE), polyvinyl chloride (PVC), and polyvinylidene chloride. The plastic supplied from the supply member 80 may be any of the above-mentioned single substances or a mixture of these substances. The plastic supplied from the supply member 80 may be a virgin product, but from the viewpoint of effective utilization of resources, recovered waste plastic may also be used. Furthermore, RDF (Refuse Derived Fuel), meat and bone meal, etc. may be added to the plastic supplied from the supply member 80 as appropriate.

[0058] In the example shown in Fig. 2, the three supply members 80 are referred to as "supply member 80a," "supply member 80b," and "supply member 80c," respectively. Fig. 4 shows a schematic diagram illustrating the relative positions of the three supply members 80. An inlet 82 is provided at each end (end of the supply member 80) of each of the supply members 80a, 80b, and 80c, through which plastic is discharged (blows) into the interior of the calciner 30. The end of the supply member 80 that includes the inlet 82 functions as a nozzle.

[0059] The end of supply member 80a that functions as a nozzle may be installed so as to extend diagonally downward. The end of supply member 80b that functions as a nozzle and the end of supply member 80c that functions as a nozzle may be installed horizontally. Supply member 80b and supply member 80c may have similar functions and configurations. The ends of supply member 80a, supply member 80b, and supply member 80c may be connected to the side wall of the calciner 30. Supply member 80a may be installed so that the plastic is transported by its own weight to inlet 82 and introduced into the calciner 30. Supply member 80b and supply member 80c may each transport the plastic to the corresponding inlet 82 using conveying air.

[0060] In the gas flow direction F inside the calciner 30, the inlet 82 of the supply member 80a is disposed downstream of the inlet 82 of each of the supply members 80b and 80c. When the gas flow direction F is along the vertical direction, the lowest position of the inlet 82 of the supply member 80a is located above the highest position of the inlet 82 of each of the supply members 80b and 80c.

[0061] In the gas flow direction F, at least a portion of the inlet 82 of the supply member 80b is disposed at the same position as at least a portion of the inlet 82 of the supply member 80c. When the gas flow direction F is along the vertical direction, the height position of at least a portion of the inlet 82 of the supply member 80b may coincide with the height position of at least a portion of the inlet 82 of the supply member 80c. In a plan view, the inlet 82 of the supply member 80a and the inlet 82 of the supply member 80b are located at different positions around the central axis of the calciner 30. In one example, in the circumferential direction, the angle between the inlet 82 of the supply member 80b and the inlet 82 of the supply member 80c (the smaller angle of deviation) may be approximately 150° to 180°, approximately 160° to 180°, or approximately 170° to 180°. The position of the inlet 82 in the circumferential direction in a plan view is defined by the center of the inlet 82.

[0062] In a plan view, the direction in which the end portions of the supply members 80 (each of the supply members 80a, 80b, and 80c) that function as nozzles extend may be perpendicular to the side wall of the calciner 30. The direction in which the end portions of the supply members 80 extend may coincide with a direction perpendicular to the inlet 82. Alternatively, in a plan view, the direction in which the end portions of the supply members 80 extend may be inclined with respect to a direction perpendicular to the side wall of the calciner 30 (a radial direction of a circumference around the central axis of the calciner 30) so as to follow the swirling flow formed in the calciner 30. In one example, the angle at which the end portions are inclined with respect to a direction perpendicular to the side wall of the calciner 30 in a plan view may be approximately 10°, 20°, 30°, or 40°.

[0063] The position at which the plastic is supplied by the supply member 80 corresponds to the position of an inlet 82 provided at the end of the supply member 80, and hereinafter this position will be referred to as the "supply position of the supply member 80." As shown in Fig. 2, in the gas flow direction F within the calciner 30, the supply position of the supply member 80a may be located downstream of the supply positions of one or more supply members 60 (the supply positions of the supply member 60a and the supply member 60b). When the gas flow direction F is along the vertical direction, the supply position of the supply member 80a is located above the supply positions of the supply member 60a and the supply member 60b.

[0064] In the gas flow direction F within the calciner 30, the supply positions of the supply member 80b and the supply member 80c may be located at a position corresponding to the supply positions of one or more supply members 70, or may be located upstream of the supply positions. In the gas flow direction F, the supply position of the supply member 80 being located at a position corresponding to the supply position of the supply member 70 means that at least a portion of the inlet 82 of the supply member 80 and at least a portion of the inlet 72 of the supply member 70 are located at the same position.

[0065] An example of the components, calorific value, and particle size distribution of the plastic supplied from one or more supply members 80 will be described below. The proximate analysis values ​​(mass %: arrival basis) of the volatile matter, moisture, fixed carbon, and ash content of the plastic may be in the following ranges. (a) The proximate analysis value of the volatile content may be 35% by mass or more, 37% by mass or more, 39% by mass or more, or 41% by mass or more. The proximate analysis value of the volatile content may be 55% by mass or less, 53% by mass or less, 51% by mass or less, or 49% by mass or less. In one example, the proximate analysis value of the volatile content is 35 to 55% by mass, or 41 to 49% by mass. (b) The proximate analysis value of the moisture content may be 25% by mass or more, 27% by mass or more, 29% by mass or more, or 31% by mass or more. The proximate analysis value of the moisture content may be 45% by mass or less, 43% by mass or less, 41% by mass or less, or 39% by mass or less. In one example, the proximate analysis value of the moisture content is 25 to 45% by mass, or 31 to 39% by mass. (c) The proximate analysis value of fixed carbon is 1% by mass or more, 2% by mass or more, 3% by mass or more, or 4% by mass or more. The proximate analysis value of fixed carbon is 10% by mass or less, 9% by mass or less, 8% by mass or less, or 7% by mass or less. In one example, the proximate analysis value of fixed carbon is 1 to 10% by mass, or 4 to 7% by mass. (d) The proximate analysis value of the ash content may be 10% by mass or more, 11% by mass or more, 12% by mass or more, or 13% by mass or more. The proximate analysis value of the ash content may be 25% by mass or less, 24% by mass or less, 23% by mass or less, or 22% by mass or less. In one example, the proximate analysis value of the ash content is 10 to 25% by mass, or 13 to 22% by mass.

[0066] In one example, the proximate analysis values ​​(on arrival) of the plastic components are 35 to 55 mass% for volatile matter, 25 to 45 mass% for moisture, 1 to 10 mass% for fixed carbon, and 10 to 25 mass% for ash. The proximate analysis values ​​of the plastic components are analytical values ​​measured and converted using the test methods and conversion methods described in JIS M8812 "Coals and cokes - Methods of proximate analysis" and JIS M8810 "Coals and cokes - General rules for sampling, analysis, and test methods."

[0067] The chemical analysis values ​​(mass %: arrival basis) of C, H, O, N, and S of the plastic may be in the following ranges: (a) The chemical analysis value of C may be 25% by mass or more, 27% by mass or more, 29% by mass or more, or 31% by mass or more. The chemical analysis value of C may be 45% by mass or less, 43% by mass or less, 41% by mass or less, or 39% by mass or less. In one example, the chemical analysis value of C is 25 to 45% by mass, or 31 to 39% by mass. (b) The chemical analysis value of H may be 3.0% by weight or more, 3.2% by weight or more, 3.4% by weight or more, or 3.6% by weight or more. The chemical analysis value of H may be 6.0% by weight or less, 5.8% by weight or less, 5.6% by weight or less, or 5.4% by weight or less. In one example, the chemical analysis value of H is 3-6% by weight, or 3.6-5.4% by weight. (c) The chemical analysis value of O may be 5% by weight or more, 6% by weight or more, 7% by weight or more, or 8% by weight or more. The chemical analysis value of O may be 20% by weight or less, 19% by weight or less, 18% by weight or less, or 17% by weight or less. In one example, the chemical analysis value of O is 5 to 20% by weight, or 8 to 17% by weight. (d) The chemical analysis value of N may be 0.5% by weight or more, 0.6% by weight or more, 0.7% by weight or more, or 0.8% by weight or more. The chemical analysis value of N may be 2.0% by weight or less, 1.9% by weight or less, 1.8% by weight or less, or 1.7% by weight or less. In one example, the chemical analysis value of N is 0.5 to 2.0% by weight, or 0.8 to 1.7% by weight. (e) The chemical analysis value of S may be 0.01% by weight or more, 0.02% by weight or more, 0.03% by weight or more, or 0.04% by weight or more. The chemical analysis value of S may be 0.1% by weight or less, 0.09% by weight or less, 0.08% by weight or less, or 0.07% by weight or less. In one example, the chemical analysis value of S is 0.01 to 0.1% by weight, or 0.04 to 0.07% by weight.

[0068] In one example, the chemical analysis values ​​(on arrival basis) of the plastic components are 25-45 mass% C, 3-6 mass% H, 5-20 mass% O, 0.5-2 mass% N, and 0.01-0.1 mass% S. The chemical analysis values ​​(air-dry basis) of the plastic components are analytical values ​​measured and converted according to the test methods and conversion methods described in JIS M8813 "Coals and cokes - Elemental analysis methods" and JIS M8810 "Coals and cokes - General rules for sampling, analysis, and test methods."

[0069] The chemical analysis values ​​(mass %: dry and ash-free basis) of C, H, O, N, and S of the plastic may be in the following ranges: (a) The chemical analysis value of C may be 55% by mass or more, 56% by mass or more, 57% by mass or more, or 58% by mass or more. The chemical analysis value of C may be 75% by mass or less, 74% by mass or less, 73% by mass or less, or 72% by mass or less. In one example, the chemical analysis value of C is 55 to 75% by mass, or 58 to 72% by mass. (b) The chemical analysis value of H may be 6.0% by weight or more, 6.2% by weight or more, 6.4% by weight or more, or 6.6% by weight or more. The chemical analysis value of H may be 10.0% by weight or less, 9.8% by weight or less, 9.6% by weight or less, or 9.4% by weight or less. In one example, the chemical analysis value of H is 6 to 10% by weight, or 6.6 to 9.4% by weight. (c) The chemical analysis value of O may be 20% by weight or more, 21% by weight or more, 22% by weight or more, or 23% by weight or more. The chemical analysis value of O may be 30% by weight or less, 29% by weight or less, 28% by weight or less, or 27% by weight or less. In one example, the chemical analysis value of O is 20-30% by weight, or 23-27% by weight. (d) The chemical analysis value of N may be 1.0% by weight or more, 1.2% by weight or more, 1.4% by weight or more, or 1.6% by weight or more. The chemical analysis value of N may be 4.0% by weight or less, 3.8% by weight or less, 3.6% by weight or less, or 3.4% by weight or less. In one example, the chemical analysis value of N is 1-4% by weight, or 1.6-3.4% by weight. (e) The chemical analysis value of S may be 0.01% by weight or more, 0.02% by weight or more, 0.03% by weight or more, or 0.04% by weight or more. The chemical analysis value of S may be 0.12% by weight or less, 0.11% by weight or less, 0.10% by weight or less, or 0.09% by weight or less. In one example, the chemical analysis value of S is 0.01 to 0.12% by weight, or 0.04 to 0.09% by weight.

[0070] In one example, the chemical analysis values ​​(on an anhydrous ash-free basis) of the plastic components are 55-75 mass% C, 6-10 mass% H, 20-30 mass% O, 1-4 mass% N, and 0.01-0.12 mass% S. The chemical analysis values ​​(on an air-dry basis) of the plastic components are analytical values ​​measured and converted according to the test methods and conversion methods described in JIS M8813 "Coals and cokes - Elemental analysis methods" and JIS M8810 "Coals and cokes - General rules for sampling, analysis, and test methods."

[0071] The calorific value of the plastic (more specifically, the lower calorific value of the plastic on arrival) may be 2000 kcal / kg or more, 2200 kcal / kg or more, 2400 kcal / kg or more, or 2600 kcal / kg or more. In this disclosure, the calorific value of the plastic refers to the lower calorific value (on arrival). The calorific value of the plastic may be 4500 kcal / kg or less, 4300 kcal / kg or less, 4100 kcal / kg or less, or 3900 kcal / kg or less. In one example, the calorific value of the plastic is 2000 to 4500 kcal / kg, or 2600 to 3900 kcal / kg.

[0072] The calorific value of plastics, i.e., the lower calorific value of plastics (on arrival), is the calorific value measured using a test method that complies with JIS M8814 "Coals and cokes - Method for measuring gross calorific value using a bomb calorimeter and method for calculating net calorific value."

[0073] The particle size distribution of the plastic (mass proportion of each particle size class) may be in the following ranges: The mass proportion (mass %) of each particle size class means the proportion of the mass of particles in that particle size class to the total mass of the plastic. (a) The content of particles having a particle size of 0.294 mm or less may be 10% by mass or more, 13% by mass or more, 15% by mass or more, or 17% by mass or more. The content of particles having a particle size of 0.294 mm or less may be 35% by mass or less, 33% by mass or less, 31% by mass or less, or 29% by mass or less. In one example, the content of particles having a particle size of 0.294 mm or less is 10 to 35% by mass, or 17 to 29% by mass. (b) The content of particles having a particle size of more than 0.294 mm and not more than 0.467 mm may be 40% by mass or more, 42% by mass or more, 44% by mass or more, or 46% by mass or more. The content of particles having a particle size of more than 0.294 mm and not more than 0.467 mm may be 60% by mass or less, 58% by mass or less, 56% by mass or less, or 54% by mass or less. In one example, the content of particles having a particle size of more than 0.294 mm and not more than 0.467 mm is 40-60% by mass, or 46-54% by mass. (c) The content of particles having a particle size of more than 0.467 mm and not more than 0.741 mm may be 15% by mass or more, 17% by mass or more, 19% by mass or more, or 21% by mass or more. The content of particles having a particle size of more than 0.467 mm and not more than 0.741 mm may be 40% by mass or less, 38% by mass or less, 36% by mass or less, or 34% by mass or less. In one example, the content of particles having a particle size of more than 0.467 mm and not more than 0.741 mm is 15 to 40% by mass, or 21 to 34% by mass. (d) Particles with a particle size greater than 0.741 mm may or may not be included.

[0074] In one example, the particle size distribution of the plastic is such that particles having a particle size of 0.294 mm or less account for 10 to 35 mass %, particles having a particle size of more than 0.294 mm and less than 0.467 mm account for 40 to 60 mass %, and particles having a particle size of more than 0.467 mm and less than 0.741 mm account for 15 to 40 mass %. In this case, particles having a particle size of more than 0.741 mm may or may not be included in the plastic.

[0075] When calculating the particle size distribution of plastics, the plastic is treated as fluff, and the fluff is converted into a sphere of the same volume. By specifying a shape factor so that the specific surface area is the same, the equivalent spherical diameter corresponding to the size of the fluff is calculated as the "particle size." Fluff measuring 10 mm long x 10 mm wide x 0.1 mm thick corresponds to a particle with an equivalent spherical diameter of 0.294 mm. Fluff measuring 20 mm long x 20 mm wide x 0.1 mm thick corresponds to a particle with an equivalent spherical diameter of 0.467 mm. Fluff measuring 40 mm long x 40 mm wide x 0.1 mm thick corresponds to a particle with an equivalent spherical diameter of 0.741 mm.

[0076] (heat generation rate) Of the total calorific value of the thermal energy sources supplied to the inside of the calciner 30 from one or more supply members 60, one or more supply members 70, and one or more supply members 80, the calorific value of ammonia is 5% to 30%, the calorific value of pulverized coal is 5% to 40%, and the calorific value of plastic is 5% to 60%. In other words, when "calorific value ratio A," "calorific value ratio C," and "calorific value ratio W" are defined as below, the calorific value ratio A is 5% to 30%, the calorific value ratio C is 5% to 40%, and the calorific value ratio W is 5% to 60%. Calorific value ratio A: The ratio of the calorific value of all ammonia supplied from one or more supply members 70 to the total calorific value. Calorific value ratio C: The ratio of the calorific value of all pulverized coal supplied from one or more supply members 60 to the total calorific value. Heat generation ratio W: The ratio of the heat generation of all plastics supplied from one or more supply members 80 to the total heat generation amount.

[0077] The total calorific value is the sum of the calorific values ​​of all thermal energy sources supplied from one or more supply members 60, all thermal energy sources supplied from one or more supply members 70, and all thermal energy sources supplied from one or more supply members 80. The sum of the calorific value ratio A, the calorific value ratio C, and the calorific value ratio W is 100%. These calorific value ratios and the total calorific value can be calculated using the supply amounts of various thermal energy sources. In this disclosure, the calorific value of ammonia refers to the lower heating value (anhydrous basis). The calorific value of ammonia may be 3000 kcal / kg or more, 3200 kcal / kg or more, 3400 kcal / kg or more, or 3600 kcal / kg or more. The calorific value of ammonia may be 6000 kcal / kg or less, 5800 kcal / kg or less, 5600 kcal / kg or less, or 5400 kcal / kg or less. In one example, the calorific value of ammonia is 3000 to 6000 kcal / kg, or 3600 to 5400 kcal / kg.

[0078] The calorific value ratio A may be 10% or more, 15% or more, or 20% or more from the viewpoint of effective use of ammonia. The calorific value ratio A may be 28% or less, 26% or less, or 25% or less from the viewpoint of suppressing inhibition of combustion of solids such as pulverized coal due to ammonia. The calorific value ratio C may be 10% or more, 15% or more, or 20% or more from the viewpoint of stabilizing combustion in the calciner 30. The calorific value ratio C may be 38% or less, 36% or less, or 35% or less from the viewpoint of reducing the amount of carbon dioxide generated. The calorific value ratio W may be 10% or more, 20% or more, or 30% or more from the viewpoint of accelerating plastic processing. The calorific value ratio W may be 55% or less, 50% or less, or 45% or less from the viewpoint of stabilizing combustion in the calciner 30.

[0079] (Fourth supply element: hot gas) The manufacturing apparatus 100 may include one or more supply members 90. In the example shown in Fig. 2, one supply member 90 is provided, but two or more supply members 90 may be provided. The supply member 90 is a member that supplies hot gas containing oxygen and having a temperature of 700°C to 1000°C to the inside of the calciner 30. The temperature of the hot gas supplied from the supply member 90 may be 800°C to 900°C. The supply member 90 may supply the extracted gas from the clinker cooler 48 to the inside of the calciner 30 as the hot gas.

[0080] An inlet is provided at the end of the supply member 90 for discharging (blowing) hot gas into the interior of the calciner 30. The position to which hot gas is supplied by the supply member 90 corresponds to the position of the inlet provided at the end of the supply member 90, and hereinafter, this position is referred to as the "supply position of the supply member 90." In the gas flow direction F within the calciner 30, the supply positions of one or more supply members 90 may correspond to the supply positions of one or more supply members 60, or may be located upstream of the supply positions and downstream of the supply positions of one or more supply members 70. In the gas flow direction F within the calciner 30, the supply position of the supply member 90 corresponding to the supply position of the supply member 60 means that at least a portion of the inlet of the supply member 90 and at least a portion of the inlet 62 of the supply member 60 are located at the same position. By injecting hot gas from the supply member 90 into the interior of the calciner 30, the combustibility of solids, including pulverized coal and plastics, can be further improved.

[0081] In the example shown in FIG. 2, the supply position of supply member 90 is located lower than the supply positions of both supply member 60a and supply member 60b. That is, the uppermost position of the inlet of supply member 90 is located lower than the lowermost position of the inlet of both supply member 60a and supply member 60b. Furthermore, the supply position of supply member 90 is located higher than the supply positions of both supply member 70a and supply member 70b. That is, the lowermost position of the inlet of supply member 90 is located higher than the uppermost position of the inlet of both supply member 70a and supply member 70b. The supply position of supply member 90 may be located between the supply positions of supply member 60 and supply member 70 and closer to the supply position of supply member 60. Unlike the example shown in FIG. 2, the height position of the supply position of supply member 90 may coincide with the height position of the supply position of supply member 60a and the height position of the supply position of supply member 60b. The fact that the height positions of the supply positions are the same means that the height position of at least a part of the inlet of one supply member is the same as the height position of at least a part of the inlet of another supply member. When another supply member 90 is provided in addition to one supply member 90, the positional relationship of the other supply member 90 with respect to supply members 60 and 70 is also the same.

[0082] When one supply member 60 and one supply member 90 are provided, in a plan view, the supply position of the supply member 90 may be approximately aligned with the position of the supply member 60 located downstream in the circumferential direction around the central axis of the calciner 30, or the angle of deviation between them may be approximately 30° or less. In this case, it is possible to more effectively increase the combustion temperature around the pulverized coal. Even when two supply members 60 and two supply members 90 are provided, the circumferential positional relationship between the supply position of the supply member 60 and the supply position of the corresponding supply member 90 may be approximately aligned or may be offset by approximately 30° or less.

[0083] [Cement clinker manufacturing method] Next, as an example of a method for producing cement clinker, a clinker production process performed in the production apparatus 100 will be described. The clinker production process performed in the production apparatus 100 includes, for example, a preheating process, a calcining process, a firing process, and a cooling process. These processes are performed in at least partially overlapping periods. The preheating process is a process in which cement raw materials are preheated in cyclones C1 to C4 by high-temperature gases including exhaust gas from the rotary kiln 40.

[0084] The calcination process is a process in which the cement raw materials are calcined in the calciner 30 using exhaust gas from the rotary kiln 40 and various thermal energy sources supplied to the interior of the calciner 30. The firing process is a process in which the cement raw materials are calcined in the rotary kiln 40 using combustion gas from the burner 44. The cooling process is a process in which the clinker produced in the rotary kiln 40 is cooled in the clinker cooler 48.

[0085] An example of the calcination step will be described in detail below. The calcination step includes, for example, a first supply step, a second supply step, a third supply step, a fourth supply step, and a heating step. The first supply step, the second supply step, the third supply step, the fourth supply step, and the heating step are each performed in at least partially overlapping periods.

[0086] The first supply step is a step of supplying pulverized coal to the inside of the calciner 30 by one or more supply members 60. In the first supply step, for example, pulverized coal is supplied from each of the supply member 60a and the supply member 60b (two supply members 60). In the first supply step, the pulverized coal may be supplied to the inside of the calciner 30 together with combustion air by one or more supply members 60.

[0087] The second supply step is a step of supplying ammonia to the inside of the calciner 30 by one or more supply members 70. In the second supply step, for example, an ammonia-containing gas is supplied from each of the supply member 70a and the supply member 70b (two supply members 70). The position at which each supply member 70 supplies ammonia in the second supply step is arranged upstream of the position at which each supply member 60 supplies pulverized coal in the first supply step, based on the gas flow direction F. In the second supply step, the ammonia-containing gas may be supplied to the inside of the calciner 30 together with combustion air having an air ratio of 0.1 to 1.0.

[0088] The third supply step is a step of supplying plastic to the inside of the calciner 30 by one or more supply members 80. In the third supply step, for example, plastic is supplied from each of supply member 80a, supply member 80b, and supply member 80c.

[0089] Of the total calorific value of the thermal energy sources supplied to the calciner 30 in the first supply step, the second supply step, and the third supply step, the calorific value of the ammonia supplied in the second supply step is 5% to 30%, the calorific value of the pulverized coal supplied in the first supply step is 5% to 40%, and the calorific value supplied in the third supply step is 5% to 60%. When the calorific value of the ammonia supplied in the second supply step (the calorific value proportion A) of the total calorific value is 5% to 30%, the sum of the calorific values ​​of the pulverized coal supplied in the first supply step and the plastic supplied in the third supply step (the sum of the calorific value proportion C and the calorific value proportion W) of the total calorific value is 70% to 95%.

[0090] The fourth supply step is a step of supplying a hot gas containing oxygen to the inside of the calciner 30 using one or more supply members 90 (for example, one or two supply members 90). The temperature of the hot gas supplied from the supply member 90 is 700°C to 1000°C. The temperature of the hot gas supplied from the supply member 90 may be 900°C to 1200°C. The extracted gas after being used to cool the clinker in the clinker cooler 48 may be used as the hot gas supplied from the supply member 90. The position from which the supply member 90 supplies the hot gas in the fourth supply step may correspond to the position from which each supply member 60 supplies pulverized coal in the first supply step, based on the gas flow direction F, or may be located upstream of that position. The position from which the supply member 90 supplies the hot gas in the third supply step may be located downstream of the position from which each supply member 70 supplies ammonia in the second supply step, based on the gas flow direction F.

[0091] The heating step is a step of heating the cement raw materials while burning ammonia gas in the calciner 30. The calcination step may include a denitration step. For example, in the denitration step, an ammonia-containing gas is supplied into the connection part 38 from an inlet 20 provided in the connection part 38 that connects the upper part (outlet 30b) of the calciner 30 and the cyclone C4. This allows the exhaust gas after being used for calcination in the calciner 30 to be denitrified.

[0092] [Simulation verification results] Next, we will explain the results of a simulation performed to verify the effect of additionally supplying ammonia to the interior of the calciner 30, where pulverized coal and plastic are introduced as a thermal energy source for the solids. The simulation was performed using the thermal fluid and powder analysis software "R-FLOW" manufactured by R-FLOW Corporation. In the simulated calciner 30, two supply members for supplying at least one of pulverized coal and ammonia were placed in the lower stage, and two supply members for supplying pulverized coal were placed in the upper stage. Hereinafter, the two supply members placed in the lower stage will be referred to as "lower stage burner 1" and "lower stage burner 2," and the two supply members placed in the upper stage will be referred to as "upper stage burner 1" and "upper stage burner 2." Lower stage burner 1 and lower stage burner 2 correspond to supply member 70a and supply member 70b, respectively, and upper stage burner 1 and upper stage burner 2 correspond to supply member 60a and supply member 60b, respectively.

[0093] In the simulated conditions for the calciner 30, three supply members for supplying plastics were arranged, one of which was arranged above the upper burners 1 and 2, and the remaining two supply members were arranged at a height approximately equal to that of the lower burners 1 and 2. Hereinafter, of the three supply members for supplying plastics, the one arranged above the upper burners 1 and 2 will be referred to as "Nozzle I," and the remaining two supply members will be referred to as "Nozzle II" and "Nozzle III." Nozzle I corresponds to supply member 80a, Nozzle II corresponds to supply member 80b, and Nozzle III corresponds to supply member 80c. In the simulation, it was assumed that only soft plastics were supplied. It was also assumed that 100% pure ammonia was supplied, and the lower heating value of ammonia (anhydrous basis, 100% purity) was 4,427 kcal / kg, or 1.86 × 10 7 J / kg.

[0094] The proximate analysis values ​​(mass %: air-dry basis), chemical analysis values ​​(mass %: air-dry basis), and chemical analysis values ​​(mass %: dry ash-free basis) of the components of the pulverized coal assumed in the simulation are shown in Table 1 below. In addition, the lower heating value of the pulverized coal (arrival basis) is set to 5,749 kcal / kg, or 2.415 x 10 7 J / kg. [Table 1]

[0095] The particle size distribution of the pulverized coal assumed in the simulation is shown in Table 2 below. [Table 2]

[0096] In Table 2 above, the cumulative mass ratio (11.00 mass%) at a particle size of 8.00 μm means the ratio of the mass of particles less than 8.00 μm to the total mass of pulverized coal. The mass ratio (6.00 mass%) at a particle size of 8.00 μm means the ratio of the mass of particles having a particle size of 4.00 μm or more and less than 8.00 μm to the total mass of pulverized coal. The same applies to the columns for particle sizes other than 8.00 μm.

[0097] The proximate analysis values ​​(mass%: arrival basis), chemical analysis values ​​(mass%: arrival basis), and chemical analysis values ​​(mass%: dry ash-free basis) of the plastic components assumed in the simulation are shown in Table 3 below. The lower heating value of the plastic (arrival basis) is 3,029 kcal / kg, or 1.27 x 10 7 J / kg. [Table 3]

[0098] The particle size distribution of the plastic assumed in the simulation is shown in Table 4 below. [Table 4]

[0099] Supplementing Table 4, it is shown that particles with a particle size of 0.294 mm (a group of fluffs that have a diameter of 0.294 mm when converted to a spherical equivalent diameter) account for 25 mass%, particles with a particle size of 0.467 mm (a group of fluffs that have a diameter of 0.467 mm when converted to a spherical equivalent diameter) account for 50 mass%, and particles with a particle size of 0.741 mm (a group of fluffs that have a diameter of 0.741 mm when converted to a spherical equivalent diameter) account for 25 mass%.

[0100] (Reference example) As a reference example, a simulation was conducted in which pulverized coal was supplied from all four burners. The simulation conditions are outlined below. Upper burners 1 and 2: The supply rate of pulverized coal from each burner was set to 0.72 t (ton) / h. Lower burners 1 and 2: The supply rate of pulverized coal from each burner was set to 0.72 t / h. In each burner, pulverized coal is transported by conveying air, and the flow rate of the conveying air is set to 500 Nm 3 / h and the oxygen concentration was 21%. - For each burner, combustion air is supplied separately from (pulverized coal + transport air), and the flow rate of the combustion air is set to 1,200 Nm 3 / h and the oxygen concentration was 18%. The flow rate of the upward flow introduced from the inlet 30a of the calciner 30 is set to 40,000 Nm 3 / h, and the oxygen concentration of the upward flow was 4%. Nozzle I: The plastic supply rate was set to 0.25 t / h, and the plastic was assumed to be fed by free fall. Nozzle II: The plastic supply rate was set to 2.1 t / h. The plastic was transported by conveying air, and the flow rate of the conveying air was set to 1600 Nm 3 / h and the oxygen concentration was 21%. Nozzle III: The plastic supply rate was set to 2.1 t / h. The plastic was transported by conveying air, and the flow rate of the conveying air was set to 1800 Nm 3 / h and the oxygen concentration was 21%.

[0101] Under the above conditions for the reference example, the calorific value ratio of pulverized coal from each burner is 14%. The calorific value ratio of plastic from nozzle I is 2%, and the calorific value ratio of plastic from each of nozzles II and III is 21%. The calorific value ratio for each burner means the ratio of the calorific value of the thermal energy source supplied from that burner to the total calorific value of the thermal energy sources supplied from upper burners 1 and 2, lower burners 1 and 2, and nozzles I, II, and III. The oxygen concentration means the concentration on a volume basis (volume %).

[0102] FIG. 5 shows the concentration source distribution of carbon dioxide (CO2) generated inside the calciner 30, obtained by a simulation according to a reference example. The contour diagram shown in FIG. 5 is the simulation result of the CO2 concentration source distribution inside the calciner 30 (vertical cross section). The color intensity in the contour diagram represents the amount of CO2 generated and lost per unit time and per unit volume. The lower end of the contour diagram corresponds to the inlet 30a of the calciner 30, and the upper end of the contour diagram corresponds to the outlet 30b (outlet) of the calciner 30. The results shown in FIG. 5 show that the combustion rate of pulverized coal is slow, and CO2 generation continues up to near the outlet of the calciner 30.

[0103] (Example) Similar to the introduction of the thermal energy source described with reference to Fig. 2 etc., a simulation was performed as an example in which plastic was supplied from nozzles I, II, and III, pulverized coal was supplied from upper stage burners 1 and 2, and ammonia was supplied from lower stage burners 1 and 2. The conditions for the simulation are outlined below. The conditions for nozzles I, II, and III and the conditions for the upward flow in the calciner 30 were the same as those in the reference example. Upper burners 1 and 2: The supply rate of pulverized coal from each burner was set to 2 t / h. In each of the upper burners 1 and 2, pulverized coal is transported by the transport air, and the flow rate of the transport air is set to 500 Nm 3 / h and the oxygen concentration was 21%. In each of the upper burners 1 and 2, combustion air is supplied separately from the pulverized coal and transport air, and the flow rate of the combustion air is set to 1,200 Nm 3 / h and the oxygen concentration was 18%. Lower burners 1 and 2: Ammonia supply volume from each burner is 1,100 Nm 3 / h. In each of the lower burners 1 and 2, combustion air is supplied separately from ammonia, and the flow rate of part of that combustion air is set to 1,200 Nm 3 / h, and the oxygen concentration was 18%. The flow rate of the remaining part of the combustion air was 500 Nm 3 / h and the oxygen concentration was 21%.

[0104] Under the above conditions for the example, the calorific value ratio of pulverized coal from each of the upper burners 1 and 2 is 16%, and the calorific value ratio of ammonia from each of the lower burners 1 and 2 is 12%. In other words, the calorific value ratio A is 24%, the calorific value ratio C is 32%, and the calorific value ratio W is 44%.

[0105] Fig. 6 shows the concentration source distribution of carbon dioxide (CO2) generated inside the calciner 30, obtained by the simulation according to the example. The simulation results shown in Fig. 6 correspond to the simulation results shown in Fig. 5. In the simulation according to the example, it can be seen that the combustion rate of pulverized coal is slow and CO2 generation continues up to near the outlet of the calciner 30.

[0106] FIG. 7 shows the concentration source distribution of ammonia (NH3) generated inside the calciner 30, obtained by a simulation according to the embodiment. The contour diagram shown in FIG. 7 is the simulation result of the concentration source distribution of NH3 inside the calciner 30 (vertical cross section). The color intensity in the contour diagram represents the amount of NH3 generated and lost per unit time and unit volume. The lower end of the contour diagram corresponds to the inlet 30a of the calciner 30, and the upper end of the contour diagram corresponds to the outlet 30b of the calciner 30. The results shown in FIG. 7 reveal that the combustion rate of ammonia is fast and that ammonia disappears immediately after being supplied from the lower burner.

[0107] Under the above conditions for the example, ammonia 1100 Nm 3 The theoretical combustion oxygen per hour is calculated from the above formula (1): 1100 × 3 / 4 = 825 Nm 3 The amount of oxygen near the lower burner 1 is calculated from the amount of combustion air supplied and the oxygen concentration as follows: 1200 × 0.18 + 500 × 0.21 = 321 Nm 3 In this case, the air ratio of the combustion air from the lower burner 1 is 321 / 825 (approximately 0.39). The oxygen near the lower burner 1 is supplied with 40000 / 2 x 0.04 = 800 Nm from half (one side) of the upward flow in the calciner 30, in addition to the oxygen in the combustion air. 3 / h of oxygen is added, for a total of 1121 Nm 3 / h, which exceeds the theoretical combustion oxygen. Due to the oxygen exceeding the theoretical combustion oxygen, the ammonia from the lower burner 1 is theoretically completely combusted. There is no ammonia near the upper burner 1 that preferentially consumes oxygen.

[0108] (Comparative Example) As a comparative example, a simulation was performed in which plastic was supplied from nozzles I, II, and III, pulverized coal was supplied from upper stage burners 1 and 2, and pulverized coal and ammonia were supplied from lower stage burners 1 and 2. The conditions for the simulation are outlined below. The conditions for nozzles I, II, and III and the conditions for the upward flow in the calciner 30 were the same as those in the reference example. Upper burner 1 and upper burner 2: The supply rate of pulverized coal from each burner was set to 0.41 t / h. Lower burner 1 and lower burner 2: The supply rate of pulverized coal from each burner is 0.41 t / h, and the supply rate of ammonia is 1,100 Nm 3 / h. Pulverized coal is transported by conveying air in each of the four burners, and the flow rate of the conveying air is set to 500 Nm 3 / h and the oxygen concentration was 21%. In each of the upper burners 1 and 2, combustion air is supplied separately from the pulverized coal and carrier air, and the flow rate of the combustion air is set to 1,200 Nm 3 / h and the oxygen concentration was 18%. In each of the lower burners 1 and 2, combustion air is supplied in addition to (pulverized coal + carrier air) and ammonia, and the flow rate of the combustion air is set to 1,200 Nm 3 / h and the oxygen concentration was 18%.

[0109] Under the above conditions for the comparative example, the calorific value ratio of pulverized coal from each of the four burners is 8%, and the calorific value ratio of ammonia from each of lower stage burner 1 and lower stage burner 2 is 12%. In the comparative example, the ratio corresponding to calorific value ratio A is the same as the calorific value ratio A in the example. The ratios corresponding to calorific value ratios C and W in the comparative example are also similar.

[0110] Fig. 8 shows the concentration source distribution of carbon dioxide (CO2) generated inside the calciner 30, obtained by a simulation according to the comparative example. The simulation results shown in Fig. 8 correspond to the simulation results shown in Figs. 5 and 6. In the simulation according to the comparative example, it can be seen that the combustion rate of pulverized coal is slow and CO2 generation continues up to near the outlet of the calciner 30.

[0111] Fig. 9 shows the concentration source distribution of ammonia (NH3) generated inside the calciner 30, obtained by a simulation according to a comparative example. The simulation results shown in Fig. 9 correspond to the simulation results shown in Fig. 7. In the simulation according to the comparative example, it is also clear that the combustion rate of ammonia is fast and that ammonia disappears immediately after being supplied from the lower burner. From the results shown in Figs. 8 and 9, it is clear that ammonia preferentially consumes oxygen near the lower burner.

[0112] Under the above conditions for the comparative example, the theoretical combustion oxygen amount for pulverized coal from the lower burner 1 was calculated as follows: From the elemental composition of pulverized coal, C 66.5 wt% (air-dry basis), H 4.0 wt% (air-dry basis), and O 7.3 wt% (air-dry basis), and taking into account the reaction equations C + O2 = CO2 and H + (1 / 4)O2 = (1 / 2)H2O, the theoretical combustion oxygen amount per kg of pulverized coal was calculated as {66.5 / 100 / 12 + (4 - 7.3 / 8) / 100 / 1 × (1 / 4)} × 22.414 = 1.41 Nm 3 / kg. When converted to 1 ton, the theoretical combustion oxygen amount is 1410 Nm 3 / t. 1100Nm from lower burner 1 3 The theoretical combustion oxygen amount for 0.41 t / h of ammonia and 0.41 t / h of pulverized coal is 825 + 0.41 × 1410 = 1403 Nm 3 / h. On the other hand, the amount of oxygen near the lower burner 1 is 1200 × 0.18 + 500 × 0.21 + 800 = 1121 Nm 3 / h. Near the lower burner 1, the amount of oxygen required for the theoretical combustion of ammonia and pulverized coal is less than the theoretical amount of oxygen required for the combustion of ammonia and pulverized coal, and ammonia, which has a faster combustion rate, consumes oxygen preferentially and burns completely, but the pulverized coal is short of oxygen and unburned fuel is generated. Near the upper burner 1, as in the example, there is no ammonia which consumes oxygen preferentially.

[0113] <About burning plastics> Focusing on the supply of plastic from nozzles I, II, and III without considering pulverized coal and ammonia, the manner in which plastic burns is common to the Reference Example, Working Example, and Comparative Example. Plastic is supplied into the calciner 30 by free fall from nozzle I, and is burned by the oxygen in the calciner 30. The theoretical amount of oxygen required for combustion of plastic was calculated as follows: From the elemental composition of plastic, C 32.8 wt% (air-dry basis), H 4.1 wt% (air-dry basis), and O 12.8 wt% (air-dry basis), taking into account the reaction equations C + O2 = CO2 and H + (1 / 4)O2 = (1 / 2)H2O, the theoretical amount of oxygen required for combustion per kg of plastic is {32.8 / 100 / 12 + (4.1 - 12.8 / 8) / 100 / 1 × (1 / 4)} × 22.414 = 0.75 Nm 3 / kg. When converted to 1 ton, the theoretical combustion oxygen amount is 750Nm 3 / t.

[0114] The theoretical amount of oxygen supplied from Nozzle II for combustion of plastic is 2.1 x 750 = 1,575 Nm 3 / h. The oxygen content of the conveying air is 1600 x 0.21 = 336 Nm 3 / h, the plastic supplied from nozzle II will have unburned fuel. The theoretical combustion oxygen amount for the plastic supplied from nozzle III is 1,575 Nm 3 / h. The oxygen content of the conveying air is 1800 x 0.21 = 378 Nm 3 / h, unburned plastic is also generated in the plastic supplied from nozzle III. The unburned plastic is burned by the oxygen in the calciner 30.

[0115] (Summary of main conditions) The main conditions for the above-mentioned reference examples, comparative examples, and working examples are shown in Table 5 below. In Table 5, the values ​​in parentheses indicate the proportion of the heat energy of each thermal energy source to the total heat energy of the thermal energy sources from the four burners and three nozzles. [Table 5]

[0116] (Comparative verification based on the theoretical amount of oxygen for combustion) The Example and the Comparative Example are compared with respect to phenomena occurring near the upper burner 1 and the lower burner 1. In the Example, ammonia is completely burned near the lower burner 1, and pulverized coal is not supplied, so the CO concentration can be lower than in the Comparative Example. Furthermore, near the upper burner 1, pulverized coal, which has a slow combustion rate, remains unburned due to a lack of oxygen. However, since there is no ammonia, which preferentially consumes oxygen, the pulverized coal is easily combusted. In the Comparative Example, unburned pulverized coal is generated near the lower burner 1 due to the introduction of ammonia. As described above, the amount of unburned pulverized coal generated in the Example is less than in the Comparative Example. Note that by introducing cooler bleed gas (e.g., gas with an oxygen concentration of 20% or more) as a hot gas into the calciner 30, the amount of unburned pulverized coal at the outlet of the calciner 30 can be reduced.

[0117] (Comparative verification of average CO and NH3 concentrations across the cross section) For each of the above-described Reference Example, Working Example, and Comparative Example, a simulation was performed to calculate the average CO concentration in a cross section at each height (by changing the height). The results calculated by the simulation are shown in Fig. 10. In the graph of Fig. 10, the horizontal axis represents the value obtained by dividing the height [m] from the bottom (furnace bottom) of the calciner 30 by the total length [m] in the vertical direction of the calciner 30, and the vertical axis represents the calculated value of the average CO concentration in a cross section perpendicular to the vertical direction.

[0118] From the graph shown in FIG. 10, the calculated values ​​at a height near the lower burners 1 and 2 (the value on the horizontal axis is around 0.23) and the calculated values ​​at a height near the outlet of the calciner 30 (the value on the horizontal axis is around 1.0) were read, and the results are shown in Table 6 below. [Table 6]

[0119] For each of the examples and comparative examples, the average NH3 concentration in a cross section was calculated for each height (by changing the height) through simulation. The Reference Example was excluded from the calculation because it did not involve the supply of ammonia. The results calculated through simulation are shown in Figure 11. In the graph of Figure 11, the horizontal axis represents the value obtained by dividing the height [m] from the bottom (furnace bottom) of the calciner 30 by the total length [m] in the vertical direction of the calciner 30, and the vertical axis represents the calculated value of the average NH3 concentration in a cross section perpendicular to the vertical direction.

[0120] From the graph shown in FIG. 11, the calculated values ​​at a height near the lower burners 1 and 2 (the value on the horizontal axis is around 0.23) and the calculated values ​​at a height near the middle of the calciner 30 (the value on the horizontal axis is around 0.32) are shown in Table 7 below. [Table 7]

[0121] From the results shown in Fig. 10 and Table 6, it can be seen that the average CO concentration in the Example was lower than that in the Comparative Example at a height near the lower burner. On the other hand, from the results shown in Fig. 11 and Table 7, there was no significant difference in the ammonia concentration. As described above, it can be seen that in the Example, compared to the Comparative Example, ammonia was combusted after the occurrence of incomplete combustion of pulverized coal was suppressed in an environment where plastic was introduced.

[0122] Summary of this disclosure The method for producing cement clinker described above includes a first supply step of supplying pulverized coal by one or more first supply members (60) to the interior (S) of a calciner (30) to which exhaust gas is introduced from a rotary kiln (40) that heats cement raw materials to produce cement clinker, a second supply step of supplying ammonia by one or more second supply members (70) to the interior (S) of the calciner (30), and a third supply step of supplying plastic by one or more third supply members (80) to the interior (S) of the calciner (30). With respect to the gas flow in the interior (S) of the calciner (30), the position at which the one or more second supply members (70) supply ammonia is located upstream of the position at which the one or more first supply members (60) supply the pulverized coal. Of the total calorific values ​​of the thermal energy sources supplied to the interior (S) of the calciner (30) from one or more first supply members (60), one or more second supply members (70), and one or more third supply members (80), the calorific value of ammonia is 5% to 30%, the calorific value of pulverized coal is 5% to 40%, and the calorific value of plastic is 5% to 60%.

[0123] The occurrence of combustion inhibition of the pulverized coal, which is a solid content, can lead to incomplete combustion of the pulverized coal and an increase in the amount of carbon monoxide (CO) generated. In response to this, by supplying ammonia upstream and pulverized coal downstream of the gas flow inside the calciner (30) (S), the extent to which combustion inhibition occurs due to a lack of oxygen for burning the pulverized coal, caused by the introduction of ammonia, can be reduced. Furthermore, when plastic is also supplied to the calciner (30) in addition to the pulverized coal, oxygen is also required for combustion of the plastic, increasing the likelihood of a lack of oxygen for burning the pulverized coal. Therefore, it is even more beneficial to reduce the extent to which combustion inhibition of the pulverized coal occurs due to the introduction of ammonia. In addition, by setting the ratio of the calorific value of ammonia to the total calorific value to 5% to 30%, combustion inhibition of solid content, such as the pulverized coal, due to the introduction of ammonia is further reduced. Therefore, the above-described production method is useful for suppressing the generation of carbon monoxide due to incomplete combustion of solid content when ammonia is supplied to the calciner in addition to the pulverized coal and plastic.

[0124] In the above-described method for producing cement clinker, in the second supplying step, ammonia may be supplied to the interior (S) of the calciner (30) together with air having an air ratio of 0.1 to 1.0.

[0125] Because the combustion rate of ammonia is high, its disappearance upstream has little effect on the combustion of pulverized coal supplied downstream. In the above method, supplying ammonia together with air at an air ratio of 0.1 to 1.0 makes it possible to more reliably eliminate ammonia immediately after supply. Therefore, this method is useful for suppressing the generation of carbon monoxide due to incomplete combustion of pulverized coal caused by the introduction of ammonia.

[0126] In the method for producing cement clinker described above, the plastic may have proximate analysis values ​​(on arrival basis) of 35-55% volatile matter, 25-45% moisture, 1-10% fixed carbon, and 10-25% ash. The plastic may have chemical analysis values ​​(on arrival basis) of 25-45% C (carbon), 3-6% H (hydrogen), 5-20% O (oxygen), 0.5-2% N (nitrogen), and 0.01-0.1% S (sulfur). The plastic may have a calorific value of 2000-4500 kcal / kg.

[0127] The above-described simulation verification confirmed that, at least when a plastic having such components and calorific value is supplied from the third supply member (80), the generation of carbon monoxide is suppressed.

[0128] In the method for producing cement clinker described above, the particle size distribution of the plastic calculated in terms of equivalent sphere diameter may be such that particles having a particle size of 0.294 mm or less account for 10 to 35 mass %, particles having a particle size of more than 0.294 mm and less than 0.467 mm account for 40 to 60 mass %, and particles having a particle size of more than 0.467 mm and less than 0.741 mm account for 15 to 40 mass %.

[0129] The above-described simulation verification confirmed that, at least when plastics having such a particle size distribution are supplied from the third supply member (80), the generation of carbon monoxide is suppressed.

[0130] In the method for producing cement clinker described above, the pulverized coal may have proximate analysis values ​​(air-dry basis) of 25-35% by mass of volatile matter, 2-4% by mass of moisture, 40-60% by mass of fixed carbon, and 10-25% by mass of ash. The pulverized coal may have chemical analysis values ​​(air-dry basis) of 60-75% by mass of C (carbon), 3-5% by mass of H (hydrogen), 6-9% by mass of O (oxygen), 1-3% by mass of N (nitrogen), and 0.1-1.0% by mass of S (sulfur). The calorific value of the pulverized coal may be 4500-6500 kcal / kg.

[0131] The above-described simulation verification confirmed that, at least when pulverized coal having such components and calorific value is supplied from the first supply member (60), the generation of carbon monoxide is suppressed.

[0132] In the method for producing cement clinker described above, the particle size distribution of the pulverized coal may be such that particles having a particle size of 8.00 μm or more and less than 16.00 μm account for 5 to 20 mass %, particles having a particle size of 16.00 μm or more and less than 32.00 μm account for 20 to 40 mass %, particles having a particle size of 32.00 μm or more and less than 64.00 μm account for 20 to 40 mass %, and particles having a particle size of 64.00 μm or more and less than 128.00 μm account for 10 to 30 mass %.

[0133] The above-described simulation verification confirmed that, at least when pulverized coal having such particle size distribution is supplied from the first supply member (60), the generation of carbon monoxide is suppressed.

[0134] The method for producing cement clinker described above may further include a fourth supplying step of supplying a hot gas containing oxygen to the interior of the calciner (30) by one or more fourth supplying members (80). The temperature of the hot gas may be 700°C to 1000°C. With respect to the gas flow in the interior (S) of the calciner (30), the position to which the one or more fourth supplying members (90) supply the hot gas may correspond to the position to which the one or more first supplying members (60) supply the pulverized coal, or may be located upstream of the position to which the one or more first supplying members (60) supply the pulverized coal and downstream of the position to which the one or more second supplying members (70) supply the ammonia.

[0135] Even if pulverized coal is supplied downstream, the supply of ammonia reduces oxygen, and oxygen may be insufficient to burn the pulverized coal because oxygen is also required for the combustion of plastics. In the above method, by supplying hot gas containing oxygen from a position corresponding to the supply position of the pulverized coal or between the supply position of the pulverized coal and the supply position of the ammonia, the combustion of the pulverized coal can be promoted and the amount of unburned pulverized coal generated can be reduced. Therefore, even when ammonia is introduced, it is useful for suppressing the generation of carbon monoxide due to incomplete combustion of the pulverized coal.

[0136] In the above-described production of cement clinker, in the fourth supplying step, the extracted gas from the clinker cooler (48) that cools the cement clinker produced in the rotary kiln (40) may be supplied as the hot gas.

[0137] In this case, the gas after being used to cool the clinker can be effectively used as hot gas for promoting the combustion of solids including pulverized coal.

[0138] The cement clinker manufacturing apparatus (100) described above includes a rotary kiln (40) that heats cement raw materials to produce cement clinker, a calciner (30) that receives exhaust gas from the rotary kiln (40) and heats the cement raw materials, one or more first supply members (60) that supply pulverized coal to the interior (S) of the calciner (30), one or more second supply members (70) that supply ammonia to the interior (S) of the calciner (30), and one or more third supply members (80) that supply plastic to the interior (S) of the calciner (30). With respect to the gas flow inside the calciner (30), the position at which the one or more second supply members (70) supply ammonia is located upstream of the position at which the one or more first supply members (60) supply pulverized coal. Of the total calorific values ​​of the thermal energy sources supplied to the inside of the calciner (30) from one or more first supply members (60), one or more second supply members (70), and one or more third supply members (80), the calorific value of ammonia is 5% to 30%, the calorific value of pulverized coal is 5% to 40%, and the calorific value of plastic is 5% to 60%.

[0139] As in the above-described manufacturing method, this manufacturing apparatus (100) is useful for suppressing the generation of carbon monoxide due to incomplete combustion of solids when ammonia is supplied to the calciner in addition to pulverized coal and plastics. [Explanation of symbols]

[0140] 100... manufacturing apparatus (cement clinker manufacturing apparatus), 30... calciner, 40... rotary kiln, 48... clinker cooler, 50... thermal energy source supply section, 60, 60a, 60b... supply member (first supply member), 70, 70a, 70b... supply member (second supply member), 80... supply member (third supply member), 90... supply member (fourth supply member), F... gas flow direction.

Claims

1. a first supplying step of supplying pulverized coal by one or more first supply members into an interior of a calciner into which exhaust gas from a rotary kiln that heats cement raw materials to produce cement clinker is introduced; a second supply step of supplying ammonia to the inside of the calciner using one or more second supply members; a third supply step of supplying plastic to the inside of the calciner using one or more third supply members, a position at which the one or more second supply members supply the ammonia is located upstream of a position at which the one or more first supply members supply the pulverized coal, based on a gas flow inside the calciner; Of the total calorific values ​​of the thermal energy sources supplied to the inside of the calciner from the one or more first supply members, the one or more second supply members, and the one or more third supply members, the calorific value of the ammonia is 5% to 30%, the calorific value of the pulverized coal is 5% to 40%, and the calorific value of the plastic is 5% to 60%. A method for producing cement clinker.

2. In the second supply step, the ammonia is supplied to the inside of the calciner together with air having an air ratio of 0.1 to 1.

0. The method for producing cement clinker according to claim 1.

3. The proximate analysis values ​​of the plastic on arrival are: volatile matter 35 to 55% by mass, moisture 25 to 45% by mass, fixed carbon 1 to 10% by mass, and ash 10 to 25% by mass; Chemical analysis values ​​of the plastic on arrival are: C (carbon) 25 to 45% by mass, H (hydrogen) 3 to 6% by mass, O (oxygen) 5 to 20% by mass, N (nitrogen) 0.5 to 2% by mass, and S (sulfur) 0.01 to 0.1% by mass; The calorific value of the plastic is 2000 to 4500 kcal / kg. The method for producing cement clinker according to claim 1 or 2.

4. The particle size distribution of the plastic calculated in terms of spherical equivalent diameter is: 10 to 35% by mass of particles having a particle size of 0.294 mm or less; 40 to 60% by mass of particles having a particle size of more than 0.294 mm and not more than 0.467 mm; The particles having a particle size of more than 0.467 mm and not more than 0.741 mm are 15 to 40% by mass. The method for producing cement clinker according to claim 1 or 2.

5. The pulverized coal has proximate analysis values ​​on an air-dry basis of a volatile matter of 25 to 35 mass%, a moisture content of 2 to 4 mass%, a fixed carbon content of 40 to 60 mass%, and an ash content of 10 to 25 mass%, Chemical analysis values ​​of the pulverized coal on an air-dry basis are: C (carbon) 60 to 75% by mass; H (hydrogen) 3 to 5% by mass; O (oxygen) 6 to 9% by mass; N (nitrogen) 1 to 3% by mass; and S (sulfur) 0.1 to 1.0% by mass; The calorific value of the pulverized coal is 4500 to 6500 kcal / kg. The method for producing cement clinker according to claim 1 or 2.

6. The particle size distribution of the pulverized coal is particles having a particle size of 8.00 μm or more and less than 16.00 μm are 5 to 20% by mass, 20 to 40% by mass of particles having a particle size of 16.00 μm or more and less than 32.00 μm; particles having a particle size of 32.00 μm or more and less than 64.00 μm are 20 to 40% by mass, Particles having a particle size of 64.00 μm or more and less than 128.00 μm are 10 to 30% by mass, The method for producing cement clinker according to claim 1 or 2.

7. a fourth supply step of supplying a hot gas containing oxygen to the inside of the calciner using one or more fourth supply members; The temperature of the hot gas is 700°C to 1000°C, With respect to the gas flow inside the calciner, the position to which the one or more fourth supply members supply the hot gas is The one or more first supply members are arranged at a position corresponding to a position where the pulverized coal is supplied or upstream of the supply position, and the one or more second supply members are arranged downstream of the position where the ammonia is supplied; The method for producing cement clinker according to claim 1 or 2.

8. In the fourth supplying step, extracted gas from a clinker cooler that cools cement clinker produced in the rotary kiln is supplied as the hot gas. The method for producing cement clinker according to claim 7.

9. a rotary kiln that heats cement raw materials to produce cement clinker; a calciner into which exhaust gas from the rotary kiln is introduced and which heats cement raw materials; One or more first supply members that supply pulverized coal to the inside of the calciner; one or more second supply members that supply ammonia to the interior of the calciner; one or more third supply members that supply plastic to the interior of the calciner; a position at which the one or more second supply members supply the ammonia is located upstream of a position at which the one or more first supply members supply the pulverized coal, based on a gas flow inside the calciner; Of the total calorific values ​​of the thermal energy sources supplied to the inside of the calciner from the one or more first supply members, the one or more second supply members, and the one or more third supply members, the calorific value of the ammonia is 5% to 30%, the calorific value of the pulverized coal is 5% to 40%, and the calorific value of the plastic is 5% to 60%. Cement clinker manufacturing equipment.

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