External combustion and internal heating type oxygen-enriched dry distillation method
By using the external combustion and internal heat-rich oxygen-enriched drying method in low-temperature distillation technology, the refueled gas and oxygen combustion generate high-temperature gas, and the gas temperature and flow rate are adjusted through the CO2 analysis tower, the problem of difficult and high cost of deep processing and utilization of coal gas is solved. The improvement of gas calorific value and component optimization have been achieved.
Patent Information
- Application Number
- CN202411393532.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-08
- Publication Date
- 2024-12-27
AI Technical Summary
The problem of the difficulty and cost of deep processing and utilization of coal gas in the existing low-temperature dry distillation technology.
The external combustion and internal heat-rich oxygen-enriched dry distillation method is adopted. High-temperature gas is generated by burning the refrigerated gas and oxygen in the gas furnace as the hot carrier of the raw coal in the carbonization furnace, and the temperature and flow of the gas are adjusted by using the CO2 analysis tower to increase the calorific value of the gas.
The calorific value of coal gas is increased, the nitrogen ratio is reduced, and the carbon dioxide ratio is increased, making coal gas more suitable for deep processing and utilization, and reducing production costs.
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Figure CN119193181A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of coal dry distillation, and in particular relates to an external combustion and internal heating type oxygen-enriched dry distillation method. Background Art
[0002] Low-rank coal refers to coal with a long flame and smoke when burning, and a low degree of coalification. The comprehensive utilization of low-rank coal by classification and quality is crucial to the construction of energy structure. Low-rank coal is suitable for medium and low temperature dry distillation processing. Through medium and low temperature dry distillation processing, low-rank coal is converted into three products: gas, liquid and solid, which has good economic and social benefits.
[0003] Medium and low temperature carbonization technology is a technology that is currently widely recognized and valued. It refers to the process of heating coal to 500~700℃ in the absence of air or with a small amount of air, and decomposing it to produce coal gas, tar and semi-coke.
[0004] After searching, the existing patent (Announcement No.: CN101497801B) discloses a method for starting a coal oxygen-enriched low-temperature dry distillation furnace, which includes placing Shenmu dry base raw coal and laying firewood at the bottom of the internal heating coal low-temperature dry distillation furnace body; at the same time, air is blown into the internal heating coal low-temperature dry distillation furnace body through a burner to ignite the firewood and the block coal layer in turn; after the block coal layer burns stably, coal gas is introduced into the dry distillation furnace to control the temperature of the high-temperature section of the dry distillation at 760℃~910℃; after the temperature of the dry distillation furnace rises stably and the furnace runs smoothly, oxygen is switched to the dry distillation furnace through the burner, and the air and gas flow rates are adjusted at the same time to keep the total oxygen supply relatively stable; during the switching process, the oxygen flow rate is appropriately increased, the combustion-supporting air flow rate is correspondingly reduced, and finally the corresponding gas flow rate is increased, and the adjustment is performed for 2 to 5 cycles until the normal operating parameter value under the set oxygen enrichment ratio is reached; the shutdown process is the opposite of the start-up process. The method has a safe, stable and controllable furnace start-up process, a stable oxygen-enriched distillation process, and easy adjustment of furnace conditions, thereby producing low-nitrogen and high-quality coal gas and realizing joint production and comprehensive utilization.
[0005] The distillation process device is the main equipment in the low-temperature distillation production process. It is divided into external heating type and internal heating type according to its heating method. At present, the domestic low-temperature distillation pyrolysis process of low-rank coal mainly uses an internal heating vertical carbonization furnace. In the existing semi-coke production process, the calorific value of coal gas is low, and the deep processing and utilization of coal gas is difficult and costly. Summary of the invention
[0006] In order to overcome the problems of difficulty and high cost in deep processing and utilization of existing coal gas, the present invention provides an external combustion internal heat oxygen-enriched carbonization method, in which the recycled coal gas and oxygen are burned in a gas furnace to generate high-temperature coal gas as a heat carrier for pyrolysis of raw coal in a carbonization furnace. The combustion temperature of the recycled coal gas and oxygen is too high, and the temperature and flow rate of the coal gas are adjusted by the low-temperature CO2 from the CO2 analysis tower. The present invention improves the calorific value of the coal gas and is more conducive to the processing and utilization of the coal gas.
[0007] The technical solution adopted by the present invention is: An external combustion and internal heating oxygen-enriched dry distillation method specifically comprises the following steps: Step 1, the coal gas coming out of the carbonization furnace enters the water scrubber for cooling and washing to remove dust and large particles of tar; Step 2, the gas washed by the water scrubber is cooled and then enters the heat exchanger for cooling; Step 3, the coal gas after cooling in step 2 enters the electric tar collector to reduce tar; Step 4, the coal gas after tar reduction in step 3 enters the CO2 absorption tower after passing through the pressure blower; after the lean liquid absorbs CO2, part of the coal gas is sent to the gas furnace, and part is sent to the downstream equipment; Step 5, the rich liquid from the CO2 absorption tower in step 4 enters the CO2 analysis tower, and the lean liquid with CO2 removed is circulated to the absorption tower to absorb CO2, and part of the CO2 removed is sent out, and part is sent to the gas furnace to adjust the gas temperature and flow; Step 6: In step 5, the recycled coal gas fed into the gas furnace is burned with oxygen in the gas furnace to generate high-temperature coal gas as a heat carrier for pyrolysis of the raw coal in the carbonization furnace. In the step 1, the temperature of the coal gas coming out of the carbonization furnace is 65°C to 80°C.
[0008] In the step 1, dust and large tar particles are removed, and large tar particles are tar particles with a diameter greater than 0.5 microns.
[0009] In the step 1, the temperature is lowered to 60° C. after washing in the water washing tower.
[0010] In the step 2, the temperature is lowered to 25°C to 40°C in the heat exchanger.
[0011] In step 3, the electric tar collector reduces the tar in the coal gas to 50-150 mg / m³.
[0012] In the step 4, the coal gas after tar reduction passes through a pressure blower and enters a CO2 absorption tower, and the coal gas outlet pressure of the pressure blower is 20-50 kPa. In step 6, if the combustion temperature of the recycled coal gas and oxygen in the combustion furnace is too high, the temperature and flow rate of the coal gas are adjusted by the low-temperature CO2 from the CO2 analysis tower.
[0013] Beneficial effects of the present invention: After the oxygen-enriched dry distillation process provided by the present invention is adopted, the nitrogen content in the coal gas components is reduced, and the carbon dioxide content is increased. The nitrogen content in the coal gas of the traditional process is 43% to 48%, and the carbon dioxide content is 6% to 9%. After the oxygen-enriched dry distillation process provided by the present invention is adopted, the nitrogen content is reduced to 5% to 10%, and the carbon dioxide content is 10% to 20%.
[0014] In the present invention, low-rank coal is dry distilled in a carbonization furnace, and the coal gas generated by dry distillation passes through a water scrubber, a heat exchanger, and an electric tar collector to separate the water, tar, and coal gas in the coal gas, and then enters a CO2 absorption tower after being pressurized by a pressure fan. The coal gas with CO2 removed enters a gas furnace and burns with oxygen, and the rich liquid (absorbent containing CO2) enters a CO2 analysis tower to separate the absorbent and CO2, and a part of CO2 is sent out and a part is sent to the gas furnace as an inert gas to adjust the temperature and flow of the hot coal gas. The lean liquid (absorbent without CO2) with CO2 removed is circulated to the CO2 absorption tower to absorb CO2. In the present invention, the recycled coal gas and oxygen are burned in the gas furnace to generate high-temperature coal gas as a heat carrier for pyrolysis of raw coal in the carbonization furnace. The combustion temperature of the recycled coal gas and oxygen is too high, and the temperature and flow of the coal gas are adjusted by the low-temperature CO2 from the CO2 analysis tower. The present invention improves the calorific value of the coal gas, which is more conducive to the processing and utilization of the coal gas. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The present invention will be further described in detail below with reference to the accompanying drawings.
[0016] Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION
[0017] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0018] Various structural schematic diagrams of the embodiments disclosed in the present invention are shown in the accompanying drawings. These figures are not drawn to scale, and some details are magnified and some details may be omitted for the purpose of clear expression. The shapes of various regions and layers shown in the figures and the relative sizes and positional relationships therebetween are only exemplary, and may deviate in practice due to manufacturing tolerances or technical limitations, and those skilled in the art may additionally design regions / layers with different shapes, sizes, and relative positions according to actual needs.
[0019] Embodiment 1: In order to overcome the problems of high difficulty and high cost in the existing deep processing and utilization of coal gas, the present invention provides Figure 1 The present invention shows an external combustion internal heat type oxygen-enriched carbonization method. In the present invention, the recycled coal gas and oxygen are burned in a gas furnace to generate high-temperature coal gas as a heat carrier for pyrolysis of raw coal in a carbonization furnace. The combustion temperature of the recycled coal gas and oxygen is too high, and the temperature and flow rate of the coal gas are adjusted by the low-temperature CO2 from the CO2 analysis tower. The present invention improves the calorific value of the coal gas and is more conducive to the processing and utilization of the coal gas.
[0020] An external combustion and internal heating oxygen-enriched dry distillation method specifically comprises the following steps: Step 1, the coal gas coming out of the carbonization furnace enters the water scrubber for cooling and washing to remove dust and large particles of tar; Step 2, the gas washed by the water scrubber is cooled and then enters the heat exchanger for cooling; Step 3, the coal gas after cooling in step 2 enters the electric tar collector to reduce tar; Step 4, the coal gas after tar reduction in step 3 enters the CO2 absorption tower after passing through the pressure blower; after the lean liquid absorbs CO2, part of the coal gas is sent to the gas furnace, and part is sent to the downstream equipment; Step 5, the rich liquid from the CO2 absorption tower in step 4 enters the CO2 analysis tower, and the lean liquid with CO2 removed is circulated to the absorption tower to absorb CO2, and part of the CO2 removed is sent out, and part is sent to the gas furnace to adjust the gas temperature and flow; Step 6: In step 5, the recycled coal gas fed into the gas furnace is burned with oxygen in the gas furnace to generate high-temperature coal gas as a heat carrier for pyrolysis of the raw coal in the carbonization furnace. like Figure 1 As shown, in the present invention, low-rank coal is dry distilled in a carbonization furnace, and the coal gas generated by dry distillation passes through a water scrubber, a heat exchanger, and an electric tar collector to separate the water, tar, and coal gas in the coal gas, and then enters a CO2 absorption tower after being pressurized by a pressure fan. The coal gas with CO2 removed enters a gas furnace and burns with oxygen, and the rich liquid (absorbent containing CO2) enters a CO2 analysis tower to separate the absorbent and CO2, and a part of CO2 is sent out and a part is sent to the gas furnace as an inert gas to adjust the temperature and flow of the hot coal gas. The lean liquid (absorbent without CO2) with CO2 removed is circulated to the CO2 absorption tower to absorb CO2. In the present invention, the recycled coal gas and oxygen are burned in the gas furnace to generate high-temperature coal gas as a heat carrier for pyrolysis of raw coal in the carbonization furnace. The combustion temperature of the recycled coal gas and oxygen is too high, and the temperature and flow of the coal gas are adjusted by the low-temperature CO2 from the CO2 analysis tower. The present invention improves the calorific value of the coal gas, which is more conducive to the processing and utilization of the coal gas.
[0021] Embodiment 2: Based on Example 1, in this embodiment, preferably, in step 1, the temperature of the coal gas coming out of the carbonization furnace is 65°C to 80°C.
[0022] Preferably, in step 1, dust and large tar particles are removed, and large tar particles are tar particles with a diameter greater than 0.5 microns.
[0023] Preferably, in step 1, the temperature is lowered to 60° C. after washing in a water washing tower.
[0024] Preferably, in step 2, the temperature is lowered to 25°C to 40°C in a heat exchanger.
[0025] In the present invention, the heat exchanger is preferably a cross-tube cooler, which can perform cooling quickly and effectively.
[0026] Preferably, in step 3, the electric tar collector reduces the tar in the coal gas to 50-150 mg / m³.
[0027] Preferably, in step 4, the coal gas after tar reduction passes through a pressure blower and enters the CO2 absorption tower, and the coal gas outlet pressure of the pressure blower is 20-50 kPa. In the present invention, the outlet pressure of the pressurized blower gas is preferably 20kPa, 25kPa, 30kPa, 35kPa, 40kPa, 45kPa. The pressure range of the pressurization is mainly related to the downstream gas pressure and the hot gas pressure of the carbonization furnace loop. The carbonization furnace gas pressure is less than 10kPa, and the carbonization furnace cannot operate normally if the pressure is too high. If the downstream gas pressure is too high, a blower can be added at the gas delivery location to increase the pressure.
[0028] Preferably, in step 6, if the combustion temperature of the recycled coal gas and oxygen in the combustion furnace is too high, the temperature and flow rate of the coal gas are adjusted by the low-temperature CO2 from the CO2 analysis tower.
[0029] In the present invention, low-rank coal is dry distilled in a carbonization furnace, and the coal gas generated by dry distillation passes through a water scrubber, a heat exchanger, and an electric tar collector to separate the water, tar, and coal gas in the coal gas, and then enters a CO2 absorption tower after being pressurized by a pressure fan. The coal gas with CO2 removed enters a gas furnace and burns with oxygen, and the rich liquid (absorbent containing CO2) enters a CO2 analysis tower to separate the absorbent and CO2, and a part of CO2 is sent out and a part is sent to the gas furnace as an inert gas to adjust the temperature and flow of the hot coal gas. The lean liquid (absorbent without CO2) with CO2 removed is circulated to the CO2 absorption tower to absorb CO2. In the present invention, the recycled coal gas and oxygen are burned in the gas furnace to generate high-temperature coal gas as a heat carrier for pyrolysis of raw coal in the carbonization furnace. The combustion temperature of the recycled coal gas and oxygen is too high, and the temperature and flow of the coal gas are adjusted by the low-temperature CO2 from the CO2 analysis tower. The present invention improves the calorific value of the coal gas, which is more conducive to the processing and utilization of the coal gas.
[0030] After the oxygen-enriched dry distillation process provided by the present invention is adopted, the nitrogen content in the coal gas components is reduced, and the carbon dioxide content is increased. The nitrogen content in the coal gas of the traditional process is 43% to 48%, and the carbon dioxide content is 6% to 9%. After the oxygen-enriched dry distillation process provided by the present invention is adopted, the nitrogen content is reduced to 5% to 10%, and the carbon dioxide content is 10% to 20%.
[0031] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.
[0032] It should also be understood that the terms used in the present specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, the singular forms "a", "an" and "the" are intended to include plural forms unless the context clearly indicates otherwise.
[0033] The above examples are merely illustrative of the present invention and do not constitute a limitation on the protection scope of the present invention. Any design that is the same or similar to the present invention belongs to the protection scope of the present invention. The device structures and method steps not described in detail in the present invention are all prior art and will not be further described in the present invention.
Claims
1. An external combustion and internal heating oxygen-enriched dry distillation method, characterized in that: The specific steps include: Step 1, the coal gas coming out of the carbonization furnace enters the water scrubber for cooling and washing to remove dust and large particles of tar; Step 2, the gas washed by the water scrubber is cooled and then enters the heat exchanger for cooling; Step 3, the coal gas after cooling in step 2 enters the electric tar collector to reduce tar; Step 4, the coal gas after tar reduction in step 3 enters the CO2 absorption tower after passing through the pressure blower; after the lean liquid absorbs CO2, part of the coal gas is sent to the gas furnace, and part is sent to the downstream equipment; Step 5, the rich liquid from the CO2 absorption tower in step 4 enters the CO2 analysis tower, and the lean liquid with CO2 removed is circulated to the absorption tower to absorb CO2, and part of the CO2 removed is sent out, and part is sent to the gas furnace to adjust the gas temperature and flow; Step 6: In step 5, the recycled coal gas fed into the gas furnace is burned with oxygen in the gas furnace to generate high-temperature coal gas as a heat carrier for pyrolysis of the raw coal in the carbonization furnace.
2. The external combustion and internal heating oxygen-enriched carbonization method according to claim 1, characterized in that: In the step 1, the temperature of the coal gas coming out of the carbonization furnace is 65°C to 80°C.
3. The external combustion and internal heating oxygen-enriched carbonization method according to claim 1, characterized in that: In the step 1, dust and large tar particles are removed, and large tar particles are tar particles with a diameter greater than 0.5 microns.
4. The external combustion and internal heating oxygen-enriched carbonization method according to claim 1, characterized in that: In the step 1, the temperature is lowered to 60° C. after washing in the water washing tower.
5. The external combustion and internal heating oxygen-enriched carbonization method according to claim 1, characterized in that: In the step 2, the temperature is lowered to 25°C to 40°C in the heat exchanger.
6. The external combustion and internal heating oxygen-enriched carbonization method according to claim 1, characterized in that: In step 3, the electric tar collector reduces the tar in the coal gas to 50-150 mg / m³.
7. The external combustion and internal heating oxygen-enriched carbonization method according to claim 1, characterized in that: In the step 4, the coal gas after tar reduction passes through a pressure blower and enters a CO2 absorption tower, and the coal gas outlet pressure of the pressure blower is 20-50 kPa.
8. The external combustion and internal heating oxygen-enriched dry distillation method according to claim 1, characterized in that: In step 6, if the combustion temperature of the recycled coal gas and oxygen in the combustion furnace is too high, the temperature and flow rate of the coal gas are adjusted by the low-temperature CO2 from the CO2 analysis tower.