Polygeneration method of biomass downflow circulation bed millisecond pyrolysis liquefaction-gasification coupling

Abstract

A polygeneration method of biomass downflow circulation bed millisecond pyrolysis liquefaction-gasification coupling is provided.

Claims

1. A polygeneration method of biomass downflow circulation bed millisecond pyrolysis liquefaction-gasification coupling comprising: S1, drying and lifting via hot air a biomass powder having an equivalent diameter of no more than 10 mm by a hot air lift pipe, and fractionating the dried biomass powder at the top of the hot air lift pipe to obtain air, fine particle biomass and biomass having large and medium particles; S2, directly venting to the outside; introducing the fine particle biomass into a gasification lift pipe through a semi-coke return valve; and passing the biomass having large and medium particles through a rotary feeder, and performing rapid mixing, temperature rise and pyrolysis in milliseconds at a top of a downflow pyrolysis reactor with a high-temperature circulating heat carrier falling through a high-temperature carrier return valve, in order to obtain pyrolysis oil and gas, semi-coke and heat carrier; S3, performing rapid separation of the pyrolysis oil and gas, semi-coke and heat carrier at a lower part of a riser of the downflow pyrolysis reactor by means of an oil and gas gas-solid separator; fractionating the separated pyrolysis oil and gas through a fractionation tower to obtain a variety of distillate petroleum products and pyrolysis dry gas; performing gasification reaction of the separated heat carrier and semi-coke with the fine particle biomass, water vapor and hot air in the gasification lift pipe and heating the heat carrier; S4, at the top of the gasification lift pipe, separating the high temperature carrier and the synthesis gas obtained by the gasification reaction and heating with two-stage gas-solid separators, mixing the separated synthesis gas which is subjected to the heat exchange with water and heat exchange with air, with the pyrolysis dry gas from the step S3 and discharging the mixture as fuel gas for power generation; transferring the separated heat carrier into a top of the downflow pyrolysis reactor as a high temperature circulating heat carrier; transferring the separated fine ash into the fine ash cooling silo and to be discharged as a silicon-potash fertilizer; S5, discharging air by a booster fan and heating the air discharged by the booster fan by an air heat-exchanger, introducing a part of the obtained hot air into the step S1 by pumping the part of the obtained hot air to a bottom of the hot air lift pipe to be the hot air lifting and drying the biomass powder, introducing another part of the obtained hot air into the step S3 and by pumping the another part of the obtained hot air into the gasification lift pipe.

2. The method according to claim 1, wherein in step S1, the gas flow rate in the hot air lift pipe is 2-18 m/s, and the outlet temperature of the hot air lift pipe is no more than 120 C.

3. The method according to claim 1, wherein in step S2, the weight ratio of the high temperature circulating heat carrier to the biomass having large and medium particles is 2-8:1.

4. The method according to claim 1, wherein in step S2, the outlet reaction temperature of the downflow pyrolysis reactor is within a range of 450 C.-600 C., and the residence time of the biomass having large and medium particles and the high temperature circulating heat carrier in the downflow pyrolysis reactor is 0.2-3 s.

5. The method according to claim 1, wherein in step S3, the reaction temperature of the gasification lift pipe ranges from 750 C. to 1,000 C., and the gas flow rate in the gasification lift pipe is 2-18 m/s.

6. The method according to claim 1, wherein in step S4, the temperature of the synthesis gas after the water heat exchanger and air heat exchanger is no more than 45 C.

7. The method according to claim 1, wherein in step S5, the temperature of the obtained hot air is no more than 450 C.

8. The method according to claim 1, wherein the water vapor is obtained by exchanging heat between water and the synthesis gas, and the temperature of water vapor is no less than 150 C.; in the gasification lift pipe, the water vapor is mixed with hot air and the mixture is applied as a gasifying agent.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic diagram of polygeneration process of biomass downflow circulation bed millisecond pyrolysis liquefaction-gasification coupling provided by the present invention.

DESCRIPTION OF THE REFERENCE SIGNS

(2) TABLE-US-00001 1. gasification lift pipe 2. gas distributor 3. intake pipe 4. inertial gas-solid 5. high-temperature 6. secondary gas-solid separator carrier return valve separator 7. fine ash cooling silo 8. downflow 9. oil and gas gas-solid pyrolysis reactor separator 10. oil and gas 11. heavy oil outlet 12. light oil outlet fractionation tower 13. wood vinegar outlet 14. booster fan 15. hot air lift pipe 16. air primary 17. upper silo 18. rotary feeder gas-solid separator 19. air secondary 20. air outlet 21. biomass powder inlet gas-solid separator 22. dry gas outlet 23. semi-coke return 24. water heat-exchanger valve 25. air heat-exchanger 26. fuel gas outlet

DETAILED DESCRIPTION OF THE EMBODIMENTS

(3) The terminals and any value of the ranges disclosed herein are not limited to the precise ranges or values, such ranges or values shall be comprehended as comprising the values adjacent to the ranges or values. As for numerical ranges, the endpoint values of the various ranges, the endpoint values and the individual point value of the various ranges, and the individual point values may be combined with one another to yield one or more new numerical ranges, which should be considered as specifically disclosed herein.

Example 1

(4) The biomass powder having an equivalent diameter of no more than 10 mm and a transmission rate of 25 t/h is introduced into the hot air lift pipe 15 from the biomass powder inlet 21 for drying and lifting, and the dried biomass powder is fractionated by an air primary gas-solid separator 16 and an air secondary gas-solid separator 19, so as to obtain air, fine particle biomass and biomass having large and medium particle;

(5) The air is directly vented to the outside from the air outlet 20, the fine particle biomass passed through a semi-coke return valve 23 and enters into a gasification lift pipe 1; the biomass having large and medium particle is performed with the rapid mixing, temperature rise and pyrolysis in milliseconds at a top of a downflow pyrolysis reactor 8 with a high-temperature circulating heat carrier falling through a high-temperature carrier return valve 5, in order to obtain pyrolysis oil and gas, semi-coke and heat carrier;

(6) The pyrolysis oil and gas, semi-coke and heat carrier are performed with rapid separation at a lower part of a riser of the downflow pyrolysis reactor 8 by means of an oil and gas gas-solid separator 9; the separated heat carrier and semi-coke pass through a semi-coke return valve 23 for air transmission and enter into the gasification lift pipe 1, and then mix with water from an intake pipe 3 and water vapor from a gas distributor 2 to perform gasification, combustion and heating; the separated pyrolysis oil and gas pass through an oil and gas fractionation tower 10 to obtain wood vinegar, light oil, heavy oil and pyrolysis dry gas; the high-temperature heat carrier and synthesis gas obtained by heating are separated by an inertial gas-solid separator 4 and a secondary gas-solid separator 6, the separated synthesis gas is subjected to two stages heat exchanges by a water heat-exchanger 24 and an air heat-exchanger 25, and is mixed with the pyrolysis dry gas 22, the mixture is applied as the fuel gas for power generation;

(7) The heat carrier having large and medium particle separated by the inertial gas-solid separator 4 enters into a top of the downflow pyrolysis reactor 8 as a high-temperature circulating carrier, and the fine ash separated by the secondary gas-solid separator 6 of heat carrier enters into a fine ash cooling silo 7 and is discharged as a silicon-potash fertilizer;

(8) The air discharged from a booster fan 14 is heated by an air heat-exchanger 25, a part of the obtained hot air is pumped to a bottom of the hot air lift pipe 15 for lifting and drying the biomass powder introduced from a biomass powder inlet 21, another part of the hot air is introduced into a bottom of the gasification lift pipe 1, and is mixed with water vapor obtained from the water heat exchanger 24, the mixture is applied as a gasifying agent, which performs a gasification reaction with the semi-coke and heats the heat carrier. The semi-coke is completely converted into gas, and the problems of the semi-coke volatiles unregulated, the semi-coke powder efflux easy to catch fire and the semi-coke not be cleaned and utilized are be avoided.

(9) Wherein, the hot air lift pipe 15 has a gas flow rate of 6 m/s, and an outlet temperature of the lift pipe is 120 C.

(10) The mixing ratio by weight of the high temperature heat carrier to the biomass powder is 8:1.

(11) The outlet reaction temperature of the downflow pyrolysis reactor 8 is 520 C., and a residence time of the biomass and heat carrier is 0.6 s.

(12) The reaction temperature in the gasification lift pipe 1 is 750 C., and the gas flow rate was 8 m/s.

(13) The temperature of the synthesis gas is 45 C. after heat exchange with water and heat exchange with air.

(14) The temperature of the hot air is 400 C.

(15) The water vapor temperature obtained through the heat exchange by water is 150 C.

(16) The biomass is pine powder. The liquid (light oil+heavy oil) yield of rapid pyrolysis is 68%, the ash content in oil (light oil+heavy oil) is less than 0.2 wt. %, the water content is lower than 1 wt. %; the yield of mixed gas (synthesis gas+pyrolysis dry gas) is 27%, the calorific value is about 2,100 kcal; and the yield of silicon-potash fertilizer is about 10%.

Example 2

(17) The process is performed according to the method in Example 1, the differences reside in that the reaction temperature in the gasification lift pipe 1 is 1,000 C.; the mixing ratio by weight of the high temperature heat carrier to the biomass powder is 2:1; the outlet reaction temperature of the downflow pyrolysis reactor 8 is 450 C.; the temperature of the hot air is 450 C.

(18) The biomass is poplar wood powder. The liquid (light oil+heavy oil) yield of rapid pyrolysis is 62%, the ash content in oil (light oil+heavy oil) is less than 0.2 wt. %, the water content is lower than 1 wt. %, the yield of mixed gas (synthesis gas+pyrolysis dry gas) is 33%, the calorific value is about 2,100 kcal, and the yield of silicon-potash fertilizer is about 10%.

Example 3

(19) The process is performed according to the method in Example 1, the differences reside in that the reaction temperature in the gasification lift pipe 1 is 900 C.; the mixing ratio by weight of the high temperature heat carrier to the biomass powder is 8:1; the outlet reaction temperature of the downflow pyrolysis reactor 8 is 600 C.; the temperature of the hot air is 350 C.

(20) The biomass is corn stover. The liquid (light oil+heavy oil) yield of rapid pyrolysis is 39%, the ash content in oil (light oil+heavy oil) is less than 0.2 wt. %, the water content is lower than 1 wt. %, the yield of mixed gas (synthesis gas+pyrolysis dry gas) is 56%, the calorific value is about 2,100 kcal, and the yield of silicon-potash fertilizer is about 10%.

Example 4

(21) The process is performed according to the method in Example 1, the differences reside in that the reaction temperature in the gasification lift pipe 1 is 930 C.; the mixing ratio by weight of the high temperature heat carrier to the biomass powder is 6:1; the outlet reaction temperature of the downflow pyrolysis reactor 8 is 480 C.; the temperature of the hot air is 420 C.

(22) The biomass is cotton straw. The liquid (light oil+heavy oil) yield of rapid pyrolysis is 55%, the ash content in oil (light oil+heavy oil) is less than 0.2 wt. %, the water content is lower than 1 wt. %, the yield of mixed gas (synthesis gas+pyrolysis dry gas) is 40%, the calorific value is about 2,100 kcal, and the yield of silicon-potash fertilizer is about 10%.

Comparative Example 1

(23) The biomass powder having an equivalent diameter of not more than 10 mm and a transmission rate of 25 t/h is introduced into a flue gas lift pipe for drying and lifting, and the biomass powder is fractionated by a flue gas primary gas-solid separator and a flue gas secondary gas-solid separator, so as to obtain air, fine particle biomass and biomass having large and medium particle;

(24) The air is directly vented to the outside, the fine particle biomass passed through a semi-coke return valve and enters into a combustion lift pipe; the biomass having large and medium particle is performed with the rapid mixing, temperature rise and pyrolysis in milliseconds at a top of a downflow pyrolysis reactor with a high-temperature circulating heat carrier falling through a high-temperature carrier return valve, in order to obtain pyrolysis oil and gas, semi-coke and heat carrier;

(25) The pyrolysis oil and gas, semi-coke and heat carrier are performed with rapid separation at a lower part of a riser of the downflow pyrolysis reactor by means of an oil and gas gas-solid separator; the separated heat carrier and semi-coke passes through a semi-coke return valve for air transmission and enter into the combustion lift pipe to perform combustion and heating; the separated pyrolysis oil and gas pass through an oil and gas fractionation tower to prepare wood vinegar, light oil, heavy oil and pyrolysis dry gas;

(26) The high-temperature heat carrier and synthesis gas obtained by heating are separated by an inertial gas-solid separator and a heat carrier secondary gas-solid separator, the separated flue gas is transmitted to a flue gas drying and lift pipe for elevating and drying the biomass powder;

(27) The large and medium particle heat carrier separated by the inertial gas-solid separator enters into a top of the downflow pyrolysis reactor as a high-temperature circulating carrier, and the fine ash separated by the secondary gas-solid separator of heat carrier enters into a fine ash cooling silo and is discharged as a silicon-potash fertilizer;

(28) Wherein, the reaction temperature in the combustion lift pipe 1 is 750 C., and the gas flow rate was 8 m/s.

(29) The mixing ratio by weight of the high temperature heat carrier to the biomass powder is 8:1.

(30) The outlet reaction temperature of the downflow pyrolysis reactor is 520 C., and a residence time of the biomass and heat carrier is 0.6 s.

(31) The flue air lift pipe has a gas flow rate of 6 m/s, and an outlet temperature of the lift pipe is 120 C.

(32) The biomass is pine powder. The liquid yield (light oil+heavy oil) of rapid pyrolysis is 60%, the ash content in oil (light oil+heavy oil) is less than 0.2 wt. %; the water content is lower than 1 wt. %; the calorific value of the pyrolysis gas is about 3,800 kcal, and the yield of silicon-potash fertilizer is about 7%, the semi-coke yield is 22%.

(33) As can be seen from the above-mentioned examples and comparative examples that the polygeneration method of biomass downflow circulation bed millisecond pyrolysis liquefaction-gasification coupling provided by the invention can be used for processing a plurality of biomass, and improving the liquid yield, performing cooperative production of fertilizer, and gasifying the semi-coke for power generation, thereby solving the difficult problem of clean and efficient utilization of the semi-coke.

(34) The above content describes in detail the preferred embodiments of the present invention, but the present invention is not limited thereto. A variety of simple modifications can be made to the technical solutions of the present invention within the scope of the technical concept of the present invention, including combining individual technical feature in any other suitable manner, such simple modifications and combinations should also be regarded as the content disclosed by the present invention, each of them falls into the protection scope of the present invention.