Production system for synthesizing methanol by using biomass

Abstract

The utility model belongs to the field of chemical production, and relates to a production system for synthesizing methanol by utilizing biomass, which comprises a biomass carbonization unit, a charcoal gasification unit and a methanol synthesis unit which are sequentially connected in series, wherein the biomass carbonization unit comprises a biomass carbonization furnace, and a biomass inlet, a charcoal outlet and a combustible gas 1 outlet are formed in the biomass carbonization furnace; the biochar gasification unit comprises a biochar gasification furnace; a biochar feeding hole, a water vapor inlet and a combustible gas outlet 2 are formed in the biochar gasification furnace; the methanol synthesis unit comprises a methanol synthesis tower, and a combustible gas 2 inlet and a methanol outlet are formed in the methanol synthesis tower; wherein the biochar outlet is connected with the biochar inlet, and the combustible gas 2 outlet is connected with the combustible gas 2 inlet. According to the technical scheme, the problem that equipment is blocked by tar can be effectively avoided in the process of synthesizing methanol by utilizing biomass, and the method is high in energy utilization rate, low in energy consumption and wide in industrial application prospect.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the field of chemical production technology relates to a kind of production system for synthesizing methanol using biomass. BACKGROUND

[0002] Since the discovery of copper-zinc-aluminum low-pressure synthesis of methanol catalyst in 1966, the methanol industry has developed rapidly. At present, the production capacity of methanol in China has exceeded 90 million tons / year. In recent years, most of the newly built methanol plants use low-pressure methanol synthesis process. Since Lurgi Company first proposed the concept of "large methanol" (Mega Methanol, annual production of million tons of methanol synthesis device) in 1997, Davy, Lurgi, Topsoe and other companies have successively proposed methanol synthesis process for large-scale methanol plant. In recent years, the research focus of methanol synthesis reactor is mainly concentrated on the development of large-scale methanol synthesis, increasing scale, energy saving and consumption reduction, as well as improving product quality and comprehensive benefits.

[0003] CN221268068U discloses a low-pressure synthesis of methanol production system, by connecting the synthesis gas pipe and the circulating gas pipe to the mixing pipe, the mixing pipe is divided into two branch pipes, which undergoes two rounds of heat exchange and cooling process, and synthesizes methanol, to solve the problems of low carbon and hydrogen utilization rate, and has the technical effects of increasing yield, saving energy and reducing consumption. However, its energy consumption needs to be further reduced.

[0004] CN118594426A discloses a biomass gasification coupled with green hydrogen to produce green methanol unit, which includes: gasification unit (A), purification unit (B), hydrogen-oxygen unit (C), synthesis unit (D); the synthesis gas (104) produced by the gasification unit (A) is used as the raw material gas (107) of the synthesis unit after passing through the purification unit (B); the oxygen (109) produced by the hydrogen-oxygen unit (C) is used as the oxygen of the gasification unit, and the hydrogen (113) produced by the hydrogen-oxygen unit (C) is used as the hydrogen source for adjusting the hydrogen-carbon ratio of the raw material gas of the synthesis unit (D); part of the purge gas (121) of the synthesis unit (D) returns to the gasification unit for recycling. However, the components of the combustible gas produced by direct gasification of biomass are complex, and the content of impurities such as tar is high. In the process of synthesizing methanol, it is difficult to purify the combustible gas, and the purification cost is also relatively high.

[0005] Therefore, the existing biomass gasification technology has some problems in practical application. First, because the biomass contains a large amount of volatile matter and tar, the combustible gas obtained by biomass gasification has a high content of tar and other impurities, and a complex purification process is needed to obtain clean combustible gas suitable for synthesizing methanol, which not only increases the production cost, but also affects the production efficiency. Secondly, in the existing technology, the tar in the combustible gas obtained by biomass gasification will block the equipment and damage the equipment. In addition, in the existing technology, the biomass preheating, carbonization and water vapor required heat energy are usually obtained by burning fossil fuels, which not only increases energy consumption, but also does not meet the requirements of energy saving and emission reduction.

[0006] Based on this, in order to further save energy and reduce consumption, improve product quality, and further reduce process difficulty and cost, it is necessary to provide a new production system and method for synthesizing methanol. Invention content

[0007] The purpose of the present application is to provide a production system for synthesizing methanol by using biomass, which comprises a biomass carbonization unit, a biochar gasification unit and a methanol synthesis unit connected in series;

[0008] The biomass carbonization unit comprises a biomass carbonization furnace, and the biomass carbonization furnace is provided with a biomass inlet, a biochar outlet and a combustible gas 1 outlet, which is used for converting biomass into biochar and combustible gas 1;

[0009] The biochar gasification unit comprises a biochar gasification furnace, and the biochar gasification furnace is provided with a biochar feed inlet, a water vapor inlet and a combustible gas 2 outlet, which is used for converting biochar into combustible gas 2;

[0010] The methanol synthesis unit comprises a methanol synthesis tower, and the methanol synthesis tower is provided with a combustible gas 2 inlet and a methanol outlet, and the combustible gas 2 is used for synthesizing methanol;

[0011] The biochar outlet is connected with the biochar feed inlet, and the combustible gas 2 outlet is connected with the combustible gas 2 inlet.

[0012] Preferably, it further comprises a biomass gasification unit for converting biomass into combustible gas 3;

[0013] The biomass gasification unit comprises a biomass gasification furnace, and the biomass gasification furnace is provided with a biomass inlet, an oxygen-containing gas inlet, an ash outlet and a combustible gas 3 outlet.

[0014] Preferably, it further comprises a combustible gas 3 combustion unit, which comprises a combustible gas 3 combustion furnace, and the combustible gas 3 combustion furnace is provided with a combustible gas 3 inlet, an oxygen-containing gas inlet and a high-temperature flue gas outlet, and the high-temperature flue gas is generated after the combustible gas 3 is burned;

[0015] The combustible gas 3 inlet is connected with the combustible gas 3 outlet in the biomass gasification unit for conveying the combustible gas 3; the biomass carbonization furnace comprises a high-temperature flue gas inlet and a high-temperature flue gas outlet, and the high-temperature flue gas outlet on the combustible gas 3 combustion furnace is connected with the high-temperature flue gas inlet of the biomass carbonization furnace, so that the high-temperature flue gas generated by the combustible gas 3 combustion furnace is conveyed to the biomass carbonization furnace for heating the biomass.

[0016] Preferably, a jacket is arranged on the outer wall of the biomass carbonization furnace.

[0017] The jacket is provided with the high-temperature flue gas inlet and the high-temperature flue gas outlet for the high-temperature flue gas to enter and exit.

[0018] The high-temperature flue gas inlet on the jacket is connected with the high-temperature flue gas outlet in the combustible gas 3 combustion unit.

[0019] Preferably, the production system further comprises a combustible gas 2 heat energy recovery unit arranged between the biomass carbonization unit and the methanol synthesis unit, which is used for exchanging the heat energy of the high-temperature combustible gas 2 generated by the biomass carbonization unit to the cooling water to become preheated water. The combustible gas heat energy recovery unit comprises a gas-liquid heat exchanger, which comprises a combustible gas 2 inlet, a combustible gas 2 outlet, a cooling water inlet and a preheated water outlet.

[0020] The combustible gas 2 inlet is connected with the combustible gas 2 outlet in the biomass carbonization unit.

[0021] The combustible gas 2 outlet is connected with the combustible gas 2 purification unit.

[0022] Preferably, the production system further comprises a biomass preheating unit.

[0023] The biomass preheating unit comprises a biomass preheating furnace, which is provided with a high-temperature flue gas inlet, a biomass raw material inlet, a biomass raw material outlet and a high-temperature flue gas outlet.

[0024] The biomass raw material inlet is used for adding the biomass raw material, and the biomass raw material outlet is used for outputting the biomass raw material preheated.

[0025] The biomass raw material outlet is connected with the biomass inlet of the biomass gasification unit and the biomass inlet of the biomass carbonization unit, and the high-temperature flue gas inlet on the biomass preheating furnace is connected with the high-temperature flue gas outlet of the biomass carbonization furnace.

[0026] Preferably, the production system further comprises a boiler unit and a superheated steam unit.

[0027] The boiler unit comprises a combustible gas 3 combustion furnace, which is connected with the combustible gas 2 heat energy recovery unit and the biomass gasification unit, and is used for combusting the combustible gas 3 to release heat and heat the preheated water into water vapor.

[0028] The combustible gas 3 combustion furnace comprises a combustible gas 3 inlet, an oxygen-containing gas inlet, a preheated water inlet, a flue gas outlet and a water vapor outlet;

[0029] The combustible gas 3 inlet of the combustible gas 3 combustion furnace is connected with the combustible gas 3 outlet of the biomass gasification furnace, and the preheated water inlet of the combustible gas 3 combustion furnace is connected with the preheated water outlet of the combustible gas 2 heat energy recovery unit;

[0030] The superheated steam unit comprises a combustible gas 1 combustion furnace for combusting combustible gas 1 to release heat to heat water vapor into superheated water vapor, wherein the combustible gas 1 combustion furnace is provided with a combustible gas 1 inlet, an oxygen-containing gas inlet, a water vapor inlet, a superheated water vapor outlet and a flue gas outlet, the water vapor inlet of the combustible gas 1 combustion furnace is connected with the water vapor outlet of the boiler unit, and the combustible gas 1 inlet is connected with the combustible gas 1 outlet in the biomass carbonization unit;

[0031] The biomass carbon gasification unit further comprises a superheated water vapor inlet, and the superheated water vapor outlet is connected with the water vapor inlet in the biomass carbon gasification unit.

[0032] Preferably, the combustible gas 2 purification unit is arranged between the combustible gas 2 outlet of the biomass carbon gasification unit and the combustible gas 2 inlet of the methanol synthesis unit, and the combustible gas 2 purification unit comprises a combustible gas 2 purification device for purifying combustible gas 2 into carbon monoxide and hydrogen.

[0033] Preferably, the production system further comprises a combustible gas 2 storage unit and a combustible gas 2 adjusting unit, the combustible gas 2 storage unit is connected with the combustible gas 2 purification unit and is used for storing purified combustible gas 2, and the storage unit is arranged between the combustible gas adjusting unit and the combustible gas 2 purification unit, and the adjusting unit is used for adjusting the proportion of carbon monoxide and hydrogen.

[0034] Preferably, the production system further comprises a flue gas environmental protection treatment unit.

[0035] Compared with the prior art, the production system of the utility model mainly realizes the following technical effects in the process of synthesizing methanol by using biomass:

[0036] 1) Avoid tar to produce the problem of equipment blockage: the existing biomass gasification technology can get the combustible gas with high content of tar and other impurities, which can cause blockage of production equipment. A complex purification process is needed to obtain clean combustible gas suitable for methanol synthesis, which not only increases the production cost, but also affects the production efficiency. Through the production system of the utility model, the biomass carbonization, biochar gasification and methanol synthesis unit are connected in series, the biomass is carbonized first, most of the volatile matters in the biomass can be converted into combustible gas 1, most of the tar is released with the combustible gas 1 in the biomass carbonization process, and the volatile matters contained in the biomass carbon obtained after carbonization are less. The biochar gasification obtains combustible gas 2, the content of tar and other impurities in the combustible gas 2 is greatly reduced. Through the segmented gas production process of biomass carbonization and biochar gasification, the combustible gas 1 and the combustible gas 2 can be collected and utilized separately. The combustible gas 2 has low content of tar and other impurities, which is used for synthesizing methanol, effectively solving this problem.

[0037] 2) High energy utilization rate and low emission: the existing technology usually adopts the way of burning fossil fuel in the process of carbonization, gasification and preparation of superheated steam required for gasification, which not only increases the energy consumption, but also does not meet the requirements of energy saving and emission reduction. The technical scheme provides heat energy for the preparation process of superheated steam required for biomass carbonization, gasification and gasification by further combustion of combustible gas 1 produced by biomass carbonization and combustible gas 3 converted from biomass by gasification, realizes efficient utilization of biomass, reduces the consumption of traditional petrochemical fuel and realizes energy saving and emission reduction.

[0038] 3) Wide industrialization application prospect: the production system of the utility model has wide application prospect in the field of biomass energy technology, chemical engineering and methanol production technology, has large market demand and good commercial value. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1 It is a structure schematic view of the production system for synthesizing methanol by using biomass.

[0040] Figure 2 It is a structure schematic view of the biomass gasification furnace.

[0041] Figure 3 It is a structure schematic view of the biomass carbonization furnace.

[0042] Figure 4 It is a structure schematic view of the biochar gasification furnace.

[0043] Figure 5 It is a structure schematic view of the combustible gas heat energy recovery device.

[0044] Figure 6 It is a structure schematic view of the boiler unit.

[0045] Figure 7 Figure 1 is a structural schematic diagram of a superheated steam device.

[0046] Figure 8 Figure 2 is a structural schematic diagram of a biomass preheating furnace.

[0047] Figure 9 Figure 3 is a structural schematic diagram of a combustible gas purification device.

[0048] Figure 10 Figure 4 is a structural schematic diagram of a methanol synthesis tower. DETAILED DESCRIPTION

[0049] The technical solutions of the present application will be further illustrated by specific embodiments. Those skilled in the art should understand that the embodiments are only to help understand the present application and should not be regarded as specific limitations of the present application.

[0050] The embodiments of the present application will be described in detail below, and examples of the embodiments are shown in the drawings. In the drawings, the sizes of layers, regions, elements and their relative sizes can be exaggerated for clarity. Identical or similar labels represent identical or similar elements or elements having identical or similar functions throughout. The embodiments described below are exemplary and are only used to explain the present application and should not be understood as limitations of the present application. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0051] Biomass carbonization refers to the process of slow decomposition of biomass under limited oxygen supply or complete lack of oxygen, and removal of volatile matter under heat to produce solid coke product. In addition to the solid coke product, combustible gas and biomass tar are also produced.

[0052] Biomass gasification refers to the process of converting high polymers of biomass into carbon monoxide, hydrogen, biomass tar and low molecular hydrocarbon combustible gas through pyrolysis, oxidation and reduction reforming reactions under certain thermodynamic conditions with the help of air or oxygen.

[0053] Methanol synthesis process refers to the synthesis of methanol through carbon monoxide and hydrogen under the action of a catalyst.

[0054] If biomass directly obtains carbon monoxide through biomass gasification, biomass tar is a volatile component of biomass. In the utilization of combustible gas after biomass gasification, tar often blocks pipelines and valves; poisons catalysts, and seriously affects the stable operation of gasification equipment, combustible gas purification equipment, synthesizer separation equipment and methanol synthesis equipment, playing a negative role.

[0055] Therefore, in order to solve the problem of equipment blockage caused by biomass tar, the present application provides a production system for synthesizing methanol by using biomass, as shown inFigure 1 As shown, including biomass carbonization unit, biochar gasification unit and methanol synthesis unit connected in series.

[0056] Wherein the biomass carbonization unit comprises a biomass carbonization furnace, the biomass carbonization furnace is provided with a biomass inlet, a biochar outlet and a combustible gas 1 outlet, for converting biomass into biochar combustible gas 1.

[0057] The biochar gasification unit comprises a biochar gasification furnace, the biochar gasification furnace is provided with a biochar feed inlet, a water vapor inlet and a combustible gas 2 outlet, for converting biochar into combustible gas 2; the methanol synthesis unit comprises a methanol synthesis tower, the methanol synthesis tower is provided with a combustible gas 2 inlet and a methanol outlet, and the combustible gas 2 is used for synthesizing methanol; wherein the biochar outlet is connected with the biochar feed inlet, and the combustible gas 2 outlet is connected with the combustible gas 2 inlet.

[0058] Through the production system of the utility model, the biomass carbonization unit, the biochar gasification unit and the methanol synthesis unit are connected in series, the biomass is carbonized first, when the biomass carbonization is converted into biochar, most of the volatile components in the biomass can be converted into combustible gas 1, and most of the tar is released with the combustible gas 1 in the biomass carbonization process, and the obtained biomass carbon after carbonization contains less volatile components. The biochar is gasified to obtain combustible gas 2, and the tar and other impurities in the combustible gas 2 are greatly reduced. Through the segmented gas production process of biomass carbonization and biochar gasification, the combustible gas 1 and the combustible gas 2 can be collected and utilized separately. The combustible gas 2 has low tar and other impurity content, is used for synthesizing methanol, and has important significance for reducing the combustible gas purification cost.

[0059] The utility model also includes a biomass gasification unit, a combustible gas 3 combustion unit, a combustible gas heat energy recovery unit, a combustible gas 2 purification unit, a modulation unit, a superheated steam unit, a boiler unit, a biomass preheating unit and a flue gas environmental protection treatment unit.

[0060] The equipment of each unit and the connection relationship will be introduced in detail below.

[0061] The biomass gasification unit is used for converting biomass into combustible gas 3.

[0062] In some embodiments, the biomass gasification unit is configured to convert biomass into combustible gas 3 under the action of a gasification agent (e.g., air, oxygen, etc.) containing oxygen gas at a temperature of 400-950°C (e.g., 400°C, 500°C, 600°C, 700°C, 800°C, 900°C, 950°C, etc.). The combustible gas 3 includes combustible gases such as carbon monoxide, hydrogen, biomass tar, and low-molecular hydrocarbons. The combustible gas 3 can be further combusted to provide heat for the biomass carbonization unit or to provide heat for the biomass preheating unit.

[0063] In some preferred embodiments, the biomass gasification unit includes a biomass gasification furnace. As shown in Figure 2 Figure 2 The biomass gasification furnace is shown in the structural diagram, and the biomass gasification furnace is provided with a biomass inlet, an oxygen-containing gas inlet (e.g., an air inlet), an ash outlet, and a combustible gas 3 outlet. The biomass inlet is used to add biomass raw materials, and limited oxygen is introduced to make the biomass undergo conversion under the action of high temperature. The ash outlet is used to discharge the ash generated by the reaction, and the combustible gas 3 outlet is used to transport the combustible gas 3 generated by the reaction to the combustible gas 3 combustion unit through the outlet.

[0064] The biomass gasification furnace can adopt the device type in the prior art, and no detailed description is given here.

[0065] In some preferred embodiments, the combustible gas 3 combustion unit includes a combustible gas 3 combustion furnace, and the combustible gas 3 combustion furnace is provided with a combustible gas 3 inlet, an oxygen-containing gas inlet, and a high-temperature flue gas outlet. The high-temperature flue gas is generated after the combustible gas 3 is combusted.

[0066] The combustible gas 3 inlet is connected with the combustible gas 3 outlet in the biomass gasification unit, and is used to transport the combustible gas 3.

[0067] In some embodiments, the combustible gas 3 combustion furnace is used to mix and combust the combustible gas 3 with the oxygen-containing gas (e.g., air or oxygen, preferably oxygen-enriched air) to generate high-temperature flue gas, and the high-temperature flue gas is introduced into the biomass carbonization unit. The specific structure of the combustible gas 3 combustion unit is not limited in the present application, and those skilled in the art can adjust it according to actual needs.

[0068] The combustible gas 3 combustion furnace can be a waste gas combustion furnace in the prior art, and no detailed structure is given here.

[0069] The flue gas generated after the combustible gas 3 is combusted is used as the heat source for biomass carbonization, which eliminates the need for fossil energy such as coal or electrical energy for providing heat. After the flue gas is used as the heat source for biomass carbonization, it can also be used for biomass preheating, thereby improving the energy utilization rate.

[0070] ​In some embodiments, the biomass carbonization unit is used to indirectly contact the biomass with the high-temperature flue gas, and the biomass is heated by the high-temperature flue gas, and the biomass is carbonized at 450-950℃ (exemplarily including 450℃, 550℃, 650℃, 750℃, 850℃, 950℃, etc.) to produce biochar and combustible gas 1. The biomass carbonization unit is not specifically limited in the present application, and can be selected or adjusted according to actual needs by those skilled in the art.

[0071] As shown in Figure 3 The biomass carbonization furnace includes a biomass inlet, a combustible gas 1 outlet, a biochar outlet, a high-temperature flue gas inlet, and a high-temperature flue gas outlet. The high-temperature flue gas outlet of the combustible gas 3 combustion furnace is connected to the high-temperature flue gas inlet of the biomass carbonization furnace, so that the high-temperature flue gas generated by the combustible gas 3 combustion furnace is transported into the biomass carbonization furnace for heating the biomass.

[0072] In preferred embodiments, the biomass carbonization unit includes a biomass carbonization furnace and a jacket structure arranged on the surface of the biomass carbonization furnace, wherein the biomass carbonization furnace includes a biomass inlet, a biochar outlet, and a combustible gas 1 outlet, and the jacket structure is provided with a high-temperature flue gas inlet and a high-temperature flue gas outlet. The biomass inlet is used to add biomass raw materials, the biochar outlet is used to transport the biochar produced by heating the biomass to the biochar gasification unit, and the combustible gas 1 outlet is used to transport the combustible gas produced by heating the biomass to the superheated steam unit. The high-temperature flue gas generated by the combustible gas 3 combustion unit enters the biomass carbonization unit through the flue gas inlet and does not directly contact the biomass raw materials, for example, through a gas-solid heat exchange device: a partition wall heat exchanger, to indirectly heat the biomass, and then the flue gas is discharged to the biomass preheating unit through the high-temperature flue gas outlet.

[0073] In some embodiments, the biochar gasification unit is used to convert the biochar into combustible gas 2 and biomass ash (including residual char, i.e., the char remaining in the biomass ash) at 450-900℃ (exemplarily including 450℃, 550℃, 650℃, 750℃, 850℃, 900℃, etc.) by passing in 700-950℃ (exemplarily including 700℃, 750℃, 800℃, 850℃, 900℃, 950℃, etc.) superheated water vapor.

[0074] As shown in Figure 4 The biochar gasification unit includes a biochar gasification furnace, which is provided with a biochar feed inlet, a superheated water vapor inlet, and a combustible gas 2 outlet, for converting the biochar into combustible gas 2; the methanol synthesis unit includes a methanol synthesis tower, which is provided with a combustible gas 2 inlet and a methanol outlet, and the combustible gas 2 is used for synthesizing methanol; wherein the biochar outlet is connected to the biochar feed inlet, and the combustible gas 2 outlet is connected to the combustible gas 2 inlet.

[0075] In some embodiments, oxygen can also be mixed with the superheated water vapor and input into the biochar gasification unit.

[0076] The biochar gasification furnace further comprises an ash outlet for collecting residual biochar.

[0077] In some embodiments, a combustible gas 2 heat energy recovery unit is arranged between the biochar gasification unit and the methanol synthesis unit. The combustible gas 2 heat energy recovery unit comprises a combustible gas heat energy recovery device, such as a gas-liquid heat exchanger. Figure 5 As shown in the figure, the gas-liquid heat exchanger is provided with a combustible gas 2 inlet, a combustible gas 2 outlet, a cooling water inlet and a preheated water outlet; the combustible gas 2 inlet is connected to the combustible gas 2 outlet in the biochar gasification unit; the combustible gas 2 outlet is connected to the combustible gas 2 purification unit; the cooling water inlet and the preheated water outlet are used for the inlet and outlet of cooling water.

[0078] In some embodiments, the function of the combustible gas 2 heat energy recovery unit is to exchange heat energy between the high-temperature combustible gas 2 and the cooling water, so that the cooling water becomes preheated water, the heat energy of the combustible gas 2 is recovered, and the combustible gas 2 is cooled.

[0079] The present application does not make more detailed limitations on the specific structure of the combustible gas 2 heat energy recovery unit, and those skilled in the art can adjust it according to actual needs.

[0080] In preferred embodiments, a boiler unit and a superheated steam unit are further included. The purpose of the boiler unit is to receive the preheated water in the combustible gas 2 heat energy recovery unit, and to heat the preheated water into water vapor under the heating action generated by the combustion of combustible gas 3 output by the biomass gasification unit, and then enter the superheated steam unit. The flue gas generated by the combustion of combustible gas 3 can be treated in the flue gas environmental protection treatment unit.

[0081] The boiler unit comprises a combustible gas 3 combustion furnace connected to the combustible gas 2 heat energy recovery unit and the biomass gasification unit.

[0082] As shown in the figure, the combustible gas 3 combustion furnace comprises a combustible gas 3 inlet, an oxygen-containing gas inlet (such as an air inlet), a preheated water inlet, a flue gas outlet and a water vapor outlet. Figure 6

[0083] The combustible gas 3 inlet of the combustible gas 3 combustion furnace is connected to the combustible gas 3 outlet of the biomass gasification furnace, and the preheated water inlet of the combustible gas 3 combustion furnace is connected to the preheated water outlet of the combustible gas 2 heat energy recovery unit.

[0084] ​In some embodiments, the purpose of the superheated steam unit is to further heat the water vapor generated in the boiler unit into 700-950℃ superheated water vapor (exemplarily including 700℃, 750℃, 800℃, 850℃, 900℃, 950℃, etc.) using the high-temperature flue gas generated by the combustion of the combustible gas 1 as a heat source, for assisting the conversion of the biochar into the combustible gas 2 in the biochar gasification unit.

[0085] As shown in Figure 7 The superheated steam unit includes a combustible gas 1 combustion furnace, which is provided with a combustible gas 1 inlet, an oxygen-containing gas inlet, a water vapor inlet, a superheated water vapor outlet (superheated steam outlet), and a flue gas outlet. The water vapor inlet of the combustible gas 1 combustion furnace is connected to the water vapor outlet of the boiler unit, the combustible gas 1 inlet is connected to the combustible gas 1 outlet in the biomass carbonization unit, and the superheated water vapor outlet is connected to the water vapor inlet in the biochar gasification unit.

[0086] The flue gas generated by the combustion of the combustible gas 1 is used as a heat source to heat the water vapor to generate 700-950℃ superheated water vapor, which fully utilizes the high calorific value of the combustible gas 1 generated in the biomass carbonization process, thereby achieving effective utilization of the combustible gas 1.

[0087] The combustible gas used for the combustion furnace for gasifying water or heating water vapor can be an existing device in the prior art, which will not be described in detail here.

[0088] In some embodiments, the role of the biochar gasification unit is to gasify the biochar into the combustible gas 2 under the action of the superheated water vapor as a gasification agent at a high temperature of 700-950℃ (exemplarily including 700℃, 750℃, 800℃, 850℃, 900℃, 950℃, etc.). The specific structure of the biochar gasification unit is not limited in the present application, and can be adjusted according to actual needs by those skilled in the art.

[0089] In preferred embodiments, the biochar gasification unit is a biochar gasification furnace, which includes a biochar feeding port, a superheated water vapor inlet, and a combustible gas 2 outlet. The biochar feeding port of the biochar gasification unit is connected to the biomass char outlet of the biomass carbonization unit for inputting the biomass char, and the superheated water vapor inlet is connected to the superheated steam unit for inputting the superheated water vapor provided by the superheated steam unit into the biochar gasification unit. The biochar gasification unit further includes an ash discharge outlet through which the ash generated by gasification is discharged, and the high-temperature combustible gas 2 generated by the gasification of the biochar is transported to the combustible gas 2 heat energy recovery unit through the combustible gas 2 outlet.

[0090] Optionally, the biochar gasification furnace further includes an oxygen-containing gas inlet for introducing a limited amount or a small amount of oxygen into the biochar gasification furnace to assist the gasification of the biochar.

[0091] In some embodiments, the production system further comprises a biomass preheating unit 1.

[0092] In some embodiments, the biomass preheating unit 1 is used to preheat and dry the biomass by using the residual heat energy of the waste flue gas after heat exchange in the biomass carbonization furnace, so as to realize efficient utilization of heat energy. The unit is a gas-solid heat exchange device, and the structure of the biomass preheating unit is not limited in the present application, and can be adjusted by those skilled in the art according to actual needs.

[0093] As shown in Figure 8 The biomass preheating unit comprises a biomass preheating furnace, and a high-temperature flue gas inlet, a biomass raw material inlet, a biomass raw material outlet and a high-temperature flue gas outlet are arranged on the biomass preheating furnace; the biomass raw material inlet is used for adding biomass raw material; the biomass raw material outlet is used for outputting preheated biomass raw material; the biomass raw material outlet is connected with a biomass inlet of a biomass gasification unit and a biomass inlet in a biomass carbonization unit; and the high-temperature flue gas inlet on the biomass preheating furnace is connected with the high-temperature flue gas outlet of the biomass carbonization furnace.

[0094] In a preferred embodiment, the high-temperature flue gas outlet is connected with an environmental protection unit of flue gas.

[0095] In some embodiments, a combustible gas 2 purification unit is arranged between a combustible gas 2 outlet of the biomass carbonization gasification unit and a combustible gas 2 inlet of a methanol synthesis unit, and the combustible gas 2 purification unit comprises a combustible gas 2 purification device for purifying the combustible gas 2 into carbon monoxide and hydrogen.

[0096] The combustible gas 2 purification unit comprises a CO purification device of gas, such as a liquid spraying device, or a liquid bubbling washing device or a Venturi tube gas washing device, which is used to wash the combustible gas 2 and remove impurities such as carbon dioxide and tar therein. The specific structure of the methanol synthesis unit is not limited in the present application, and can be adjusted by those skilled in the art according to actual needs.

[0097] In a preferred embodiment, the combustible gas 2 purification unit is a spraying device, as shown in Figure 9 which comprises a combustible gas 2 inlet, a combustible gas 2 outlet, a washing water inlet, a washing water outlet and the like, wherein the combustible gas 2 inlet is used to be connected with the combustible gas 2 outlet in the combustible gas 2 heat energy recovery unit, and the combustible gas 2 outlet is used to discharge the combustible gas 2 in the combustible gas 2 purification unit to the adjusting unit.

[0098] In the preferred embodiment, a combustible gas 2 storage unit is also included, which is connected to the combustible gas 2 purification unit for storing the purified combustible gas 2; the combustible gas 2 storage unit is between the combustible gas regulating unit and the combustible gas 2 purification unit, and the combustible gas 2 regulating unit is used to regulate the ratio of carbon monoxide and hydrogen in the combustible gas 2 storage unit and then transmit them to the methanol synthesis unit.

[0099] As shown in Figure 10 , the device of the methanol synthesis tower includes a combustible gas 2 inlet, a methanol product outlet, and a residual combustible gas 2 outlet.

[0100] In some embodiments, the methanol synthesis unit includes a methanol synthesis tower, which is used for synthesizing methanol. The specific structure of the storage unit, the carbon monoxide and hydrogen regulating unit, and the methanol synthesis unit is not limited in the present application, and can be adjusted by those skilled in the art according to actual needs.

[0101] In some embodiments, the purpose of the flue gas environmental protection treatment unit is to treat waste flue gas. The specific structure of the flue gas environmental protection treatment unit is not limited in the present application, and can be adjusted by those skilled in the art according to actual needs.

[0102] In the present embodiment, some connecting pipeline units are also required for transmitting various combustible gases, oxygen, water vapor, flue gas, etc., and some solid transmission units are required for transporting biomass to the system, transmitting biomass and biochar between different units, and collecting ash and slag converted from biomass, etc. These belong to the design according to actual needs by those skilled in the art, and are not specifically limited herein.

[0103] In some embodiments, the present application provides a method for synthesizing methanol from biomass according to the above production system, wherein the synthesis process includes:

[0104] (1) Biomass gasification and combustion heat supply: biomass is gasified into combustible gas 3 by a biomass gasification device using air as a gasification agent, and high-temperature flue gas generated by combustion of the combustible gas 3 is used as a heat source for preheating biomass in step 2 or / and biomass carbonization in step 2 or / and a boiler unit.

[0105] (2) Biomass carbonization: the flue gas generated by combustion of the combustible gas 3 after biomass gasification is used as a heat source to indirectly heat biomass materials, and the biomass is obtained at 450-950℃ (exemplary temperatures include 450℃, 550℃, 650℃, 750℃, 850℃, 950℃, etc.) to obtain solid residues (biochar) and combustible gas 1, and the preferred temperature is 500-700℃ (for example, 500℃, 550℃, 600℃, 650℃, 700℃, etc.), and the biomass carbon after the reaction is transferred to a biochar gasification device in a sealed manner while hot.

[0106] (3) Biochar gasification: biochar is gasified at 450-900℃ (exemplarily including 450℃, 550℃, 650℃, 750℃, 850℃, 900℃, etc.) by passing 700-950℃ (exemplarily including 700℃, 750℃, 800℃, 850℃, 900℃, 950℃, etc.) superheated steam to convert into combustible gas 2 and biochar ash (including residual char, i.e. char remaining in the biochar ash).

[0107] (4) Heat energy recovery of combustible gas 2: high-temperature combustible gas 2 prepared by step 3 is passed through a combustible gas 2 heat energy recovery unit to change cooling water into preheated water through heat exchange.

[0108] (5) Preparation of superheated steam: combustible gas 3 produced in step 1 is combusted by a boiler unit to heat water steam produced by a water boiler; the water steam is further heated by a superheated steam unit to prepare 700-950℃ (exemplarily including 700℃, 750℃, 800℃, 850℃, 900℃, 950℃, etc.) superheated steam, which is transmitted to the biochar gasification step of step 3.

[0109] (6) Purification of combustible gas 2: after indirect heat exchange between combustible gas 2 and water, the combustible gas 2 is washed and purified in a combustible gas 2 purification unit with lye water to remove impurities such as carbon dioxide and tar to obtain purified combustible gas 2 mainly composed of carbon monoxide and hydrogen, and stored in a combustible gas 2 storage unit.

[0110] (7) Synthesis of methanol: the proportion of carbon monoxide and hydrogen in purified combustible gas 2 is adjusted by an adjusting unit to obtain synthesis gas with a hydrogen and carbon monoxide proportion of 2.1-1.9 (exemplarily including 2.1, 2, 1.9, etc.), and the synthesis gas is used to synthesize methanol in a methanol synthesis tower.

[0111] Although the embodiments of the present application have been shown and described above, it should be understood that the above embodiments are exemplary and should not be construed as limiting the present application, and those of ordinary skill in the art can make changes, modifications, replacements and variations to the above embodiments without departing from the principles and purposes of the present application within the scope of the present application.

Claims

1. A production system for synthesizing methanol using biomass, characterized by comprising: The production system comprises a biomass carbonization unit, a biochar gasification unit and a methanol synthesis unit connected in series; The biomass carbonization unit comprises a biomass carbonization furnace, wherein a biomass inlet, a biochar outlet and a combustible gas 1 outlet are arranged on the biomass carbonization furnace, and the biomass carbonization furnace is used for converting biomass into biochar and combustible gas 1; The biochar gasification unit comprises a biochar gasification furnace, wherein a biochar feeding inlet, a water vapor inlet and a combustible gas 2 outlet are arranged on the biochar gasification furnace, and the biochar gasification furnace is used for converting biochar into combustible gas 2; The methanol synthesis unit comprises a methanol synthesis tower, wherein a combustible gas 2 inlet and a methanol outlet are arranged on the methanol synthesis tower, and the combustible gas 2 is used for synthesizing methanol; The biochar outlet is connected with the biochar feeding inlet, and the combustible gas 2 outlet is connected with the combustible gas 2 inlet.

2. The production system according to claim 1, characterized in that, A biomass gasification unit is further included for converting biomass into combustible gas 3; The biomass gasification unit comprises a biomass gasification furnace, wherein a biomass inlet, an oxygen-containing gas inlet, an ash outlet and a combustible gas 3 outlet are arranged on the biomass gasification furnace.

3. The production system according to claim 2, characterized in that, A combustible gas 3 combustion unit is further included, which comprises a combustible gas 3 combustion furnace, wherein a combustible gas 3 inlet, an oxygen-containing gas inlet and a high-temperature flue gas outlet are arranged on the combustible gas 3 combustion furnace, and the high-temperature flue gas is generated after the combustible gas 3 is combusted; The combustible gas 3 inlet is connected with the combustible gas 3 outlet in the biomass gasification unit for conveying the combustible gas 3; the biomass carbonization furnace comprises a high-temperature flue gas inlet and a high-temperature flue gas outlet, and the high-temperature flue gas outlet on the combustible gas 3 combustion furnace is connected with the high-temperature flue gas inlet of the biochar gasification furnace, so that the high-temperature flue gas generated by the combustible gas 3 combustion furnace is conveyed into the biomass carbonization furnace for heating the biomass.

4. The production system according to claim 3, characterized in that A jacket is arranged on the outer wall of the biomass carbonization furnace; The jacket comprises the high-temperature flue gas inlet and the high-temperature flue gas outlet for conveying the high-temperature flue gas in and out; The high-temperature flue gas inlet on the jacket is connected with the high-temperature flue gas outlet in the combustible gas 3 combustion unit.

5. The production system of claim 4, wherein, A combustible gas 2 heat energy recovery unit is further included, which is arranged between the biochar gasification unit and the methanol synthesis unit, and is used for exchanging the heat energy of the high-temperature combustible gas 2 generated by the biochar gasification unit with cooling water to become preheated water; the combustible gas heat energy recovery unit comprises a gas-liquid heat exchanger, wherein a combustible gas 2 inlet, a combustible gas 2 outlet, a cooling water inlet and a preheated water outlet are arranged on the gas-liquid heat exchanger; The combustible gas 2 inlet is connected with the combustible gas 2 outlet in the biochar gasification unit; The combustible gas 2 outlet is connected with a combustible gas 2 purification unit.

6. The production system of claim 5, wherein, The production system further comprises a biomass preheating unit; The biomass preheating unit comprises a biomass preheating furnace, wherein a high-temperature flue gas inlet, a biomass raw material inlet, a biomass raw material outlet and a high-temperature flue gas outlet are arranged on the biomass preheating furnace; The biomass raw material inlet is used for adding biomass raw material; The biomass raw material outlet is used for outputting the biomass raw material preheated by the biomass preheating unit; The biomass raw material outlet is connected with the biomass inlet of the biomass gasification unit and the biomass inlet of the biomass carbonization unit; the high-temperature flue gas inlet on the biomass preheating furnace is connected with the high-temperature flue gas outlet of the biomass carbonization furnace.

7. The production system of claim 5, wherein, The production system further comprises a boiler unit and a superheated steam unit; The boiler unit comprises a combustible gas 3 combustion furnace connected with a combustible gas 2 heat energy recovery unit and a biomass gasification unit, for burning combustible gas 3 to release heat to heat the preheated water into water vapor; The combustible gas 3 combustion furnace comprises a combustible gas 3 inlet, an oxygen-containing gas inlet, a preheated water inlet, a flue gas outlet and a water vapor outlet; The combustible gas 3 inlet of the combustible gas 3 combustion furnace is connected with the combustible gas 3 outlet of the biomass gasification furnace, and the preheated water inlet of the combustible gas 3 combustion furnace is connected with the preheated water outlet of the combustible gas 2 heat energy recovery unit; The superheated steam unit comprises a combustible gas 1 combustion furnace for burning combustible gas 1 to release heat to heat the water vapor into superheated steam, and the combustible gas 1 combustion furnace is provided with a combustible gas 1 inlet, an oxygen-containing gas inlet, a water vapor inlet, a superheated steam outlet and a flue gas outlet, the water vapor inlet of the combustible gas 1 combustion furnace is connected with the water vapor outlet of the boiler unit, and the combustible gas 1 inlet is connected with the combustible gas 1 outlet in the biomass carbonization unit; The biomass carbonization unit further comprises a superheated steam inlet, and the superheated steam outlet is connected with the water vapor inlet in the biomass carbonization unit.

8. The production system of claim 1, wherein, A combustible gas 2 purification unit is further arranged between the combustible gas 2 outlet of the biomass carbonization unit and the combustible gas 2 inlet of the methanol synthesis unit, and the combustible gas 2 purification unit comprises a combustible gas 2 purification device for purifying the combustible gas 2 into carbon monoxide and hydrogen.

9. The production system of claim 8, wherein, A combustible gas 2 storage unit and a combustible gas 2 adjusting unit are further included, the combustible gas 2 storage unit is connected with the combustible gas 2 purification unit for storing the purified combustible gas 2, and the combustible gas 2 storage unit is arranged between the combustible gas adjusting unit and the combustible gas 2 purification unit, and the adjusting unit is used for adjusting the proportion of carbon monoxide and hydrogen.

10. The production system of claim 1, wherein, The production system further comprises a flue gas environmental protection treatment unit.

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