CN-224212614-U - Production system for carbonizing and gasifying biomass and combining urea synthesis

CN224212614UCN 224212614 UCN224212614 UCN 224212614UCN-224212614-U

Abstract

The utility model belongs to the field of chemical production, and relates to a production system for combining biomass carbonization and gasification with urea synthesis, which comprises a biomass carbonization unit, a biochar gasification unit, a water gas shift reaction unit, an ammonia synthesis unit and a urea synthesis unit which are sequentially connected in series, wherein the biomass carbonization unit comprises a biomass carbonization furnace, the biochar gasification unit comprises the biochar gasification furnace, the water gas shift reaction unit comprises a shift reactor and is used for converting carbon monoxide and water vapor in combustible gas 2 into hydrogen and carbon dioxide through reaction, the ammonia synthesis unit comprises an ammonia synthesis tower, and the urea synthesis unit comprises a urea synthesis tower. According to the technical scheme, the problems that tar is blocked to equipment, deposition on the surface of a catalyst affects the efficiency of urea synthesis and the like can be effectively avoided in a urea synthesis unit process, and the production efficiency and the yield are improved.

Inventors

GAN LIHUI
LIN LU
TANG XING

Assignees

厦门大学

Dates

Publication Date: 20260508
Application Date: 20250417

Claims (8)

1. The production system for carbonizing and gasifying biomass and combining urea synthesis is characterized by comprising a biomass carbonization unit, a biochar gasification unit, a water gas shift reaction unit, an ammonia synthesis unit and a urea synthesis unit which are sequentially connected in series; the biomass carbonization unit comprises a biomass carbonization furnace, wherein the biomass carbonization furnace comprises a biomass inlet, a biochar outlet and a combustible gas 1 outlet, and the biomass carbonization furnace is used for converting biomass into biochar and the combustible gas 1; The biochar gasification unit comprises a biochar gasification furnace, the biochar gasification furnace comprises a biochar inlet and a flammable gas 2 outlet, the biochar gasification furnace is used for gasifying and converting the biochar into the flammable gas 2, the biochar inlet is connected with the biochar outlet, and the flammable gas 2 comprises carbon monoxide; The water gas shift reaction unit comprises a shift reactor, wherein the shift reactor is used for converting carbon monoxide and water vapor in the combustible gas 2 into hydrogen and carbon dioxide through reaction, the shift reactor comprises a combustible gas 2 inlet, a water vapor inlet, a hydrogen outlet and a carbon dioxide outlet, and the combustible gas 2 inlet is connected with the combustible gas 2 outlet; The ammonia synthesis unit comprises an ammonia synthesis tower, wherein the ammonia synthesis tower comprises a hydrogen inlet and an ammonia outlet, and the hydrogen inlet is connected with the hydrogen outlet; The urea synthesis unit comprises a urea synthesis tower, the urea synthesis tower comprises an ammonia inlet and a carbon dioxide inlet, the ammonia inlet is connected with the ammonia outlet, and the carbon dioxide inlet is connected with the carbon dioxide outlet.
2. The production system of claim 1, further comprising a separation unit connected to the water gas shift reaction unit for separating hydrogen and carbon dioxide, and a hydrogen storage unit and a carbon dioxide storage unit for storing the hydrogen and the carbon dioxide separated by the separation unit, respectively, the hydrogen storage unit and the carbon dioxide storage unit comprising a hydrogen storage tank and a carbon dioxide storage tank, respectively.
3. The production system according to claim 2, further comprising an ammonia storage unit, wherein the ammonia storage unit comprises an ammonia storage tank connected to the ammonia synthesis tower for storing ammonia synthesized by the ammonia synthesis tower.
4. The production system according to claim 1, further comprising a combustible gas 1 combustion unit, wherein the combustible gas 1 combustion unit comprises a combustible gas 1 combustion furnace for combusting the combustible gas 1 to generate high-temperature flue gas, the combustible gas 1 combustion furnace comprises a combustible gas 1 inlet, an oxygen-containing gas inlet and a high-temperature flue gas outlet, the outer wall of the biomass carbonization furnace comprises a jacket, the jacket comprises the flue gas inlet and the flue gas outlet for entering and exiting high-temperature flue gas, the combustible gas 1 inlet is connected with the combustible gas 1 outlet, and the flue gas inlet on the jacket is connected with the high-temperature flue gas outlet of the combustible gas 1 combustion furnace.
5. The production system of claim 4, further comprising a biomass preheating unit; the biomass preheating unit comprises a biomass preheating furnace, wherein a smoke inlet, a biomass outlet and a smoke outlet are formed in the biomass preheating furnace; The biomass raw material outlet is used for outputting preheated biomass; The biomass raw material outlet is connected with a biomass inlet of the biomass carbonization unit, and a flue gas inlet on the biomass preheating furnace is connected with a flue gas outlet of the biomass carbonization furnace.
6. The production system according to claim 1, further comprising a combustible gas 2 heat recovery unit connected to the biochar gasification unit for exchanging heat energy of the combustible gas 2 generated by the biochar gasification unit to cooling water to thereby change the cooling water into preheated water; the combustible gas heat energy recovery unit comprises a gas-liquid heat exchanger, wherein the gas-liquid heat exchanger comprises a combustible gas 2 inlet, a combustible gas 2 outlet, a cooling water inlet and a preheated water outlet; the inlet of the combustible gas 2 is connected with the outlet of the combustible gas 2 in the biochar gasification unit.
7. The production system of claim 1, further comprising a boiler unit coupled to the biochar gasification unit for heating the preheated water to steam; The boiler unit comprises a combustion furnace or an electric heating furnace, wherein the combustion furnace or the electric heating furnace comprises a preheating water inlet and a steam outlet, the preheating water inlet is connected with the preheating water outlet of the combustible gas 2 heat energy recovery unit, the biochar gasification furnace comprises a steam inlet, and the steam outlet is connected with the steam inlet of the biochar gasification furnace.
8. The production system according to claim 1 or 2, further comprising a fuel gas 2 purification unit, wherein the fuel gas 2 purification unit is connected to the fuel gas 2 outlet of the biochar gasification unit, and wherein the fuel gas 2 purification unit comprises a fuel gas 2 purification device.

Description

Production system for carbonizing and gasifying biomass and combining urea synthesis Technical Field The utility model belongs to the technical field of chemical production, and relates to a production system for carbonizing and gasifying biomass and combining urea synthesis. Background The traditional method for synthesizing urea is to convert biomass or coal into synthesis gas through biomass gasification or coal gasification, then to carry out chemical reaction on the synthesis gas to synthesize ammonia, and then to synthesize the chemical fertilizer raw material urea by ammonia. However, the gas components generated by direct gasification of biomass are complex, and mainly contain hydrogen, carbon monoxide, carbon dioxide, alkanes (e.g., methane) and the like, and also contain impurities such as tar, sulfur-containing compounds, nitrogen-containing compounds, dust and the like. If the combustible gas is directly used for urea synthesis, the key challenges of tar and impurity influence exist. Tar produced in the gasification process is easy to deposit on the surface of a pipeline or a catalyst, so that the catalyst is poisoned, the problems of ammonia synthesis, inhibition in the urea synthesis process and the like are affected, and the product yield is reduced. Therefore, in the urea synthesis process, carbon dioxide and hydrogen are required to be purified, but the purification difficulty is high at present, and the purification cost is relatively high. Based on the above, in order to further save energy and reduce consumption, improve product quality, and further reduce process difficulty and cost, it is very necessary to provide a new urea synthesis production system. Disclosure of utility model The application aims to provide a production system for carbonizing and gasifying biomass and synthesizing urea in a combined way, which comprises a biomass carbonization unit, a biochar gasification unit, a water gas shift reaction unit, an ammonia synthesis unit and a urea synthesis unit which are sequentially connected in series; the biomass carbonization unit comprises a biomass carbonization furnace, wherein the biomass carbonization furnace comprises a biomass inlet, a biochar outlet and a combustible gas 1 outlet, and the biomass carbonization furnace is used for converting biomass into biochar and the combustible gas 1; The biochar gasification unit comprises a biochar gasification furnace, the biochar gasification furnace comprises a biochar inlet and a flammable gas 2 outlet, the biochar gasification furnace is used for gasifying and converting the biochar into the flammable gas 2, the biochar inlet is connected with the biochar outlet, and the flammable gas 2 comprises carbon monoxide; the water gas shift reaction unit comprises a shift reactor, wherein the shift reactor is used for converting carbon monoxide and water vapor in the combustible gas 2 into hydrogen and carbon dioxide through reaction, the shift reactor comprises a combustible gas 2 inlet, a water vapor inlet, a hydrogen outlet and a carbon dioxide outlet, and the combustible gas 2 inlet is connected with the combustible gas 2 outlet; The ammonia synthesis unit comprises an ammonia synthesis tower, wherein the ammonia synthesis tower comprises a hydrogen inlet and an ammonia outlet, and the hydrogen inlet is connected with the hydrogen outlet; The urea synthesis unit comprises a urea synthesis tower, the urea synthesis tower comprises an ammonia inlet and a carbon dioxide inlet, the ammonia inlet is connected with the ammonia outlet, and the carbon dioxide inlet is connected with the carbon dioxide outlet. Preferably, the production system further comprises a separation unit, wherein the separation unit is connected with the water gas shift reaction unit and is used for separating hydrogen and carbon dioxide, and the production system further comprises a hydrogen storage unit and a carbon dioxide storage unit which are used for respectively storing the hydrogen and the carbon dioxide separated by the separation unit and respectively comprise a hydrogen storage tank and a carbon dioxide storage tank. Preferably, the production system further comprises an ammonia storage unit, wherein the ammonia storage unit comprises an ammonia storage tank, and the ammonia storage tank is connected with the ammonia synthesis tower and is used for storing ammonia synthesized by the ammonia synthesis tower. Preferably, the production system further comprises a combustible gas 1 combustion unit, the combustible gas 1 combustion unit comprises a combustible gas 1 combustion furnace for combusting the combustible gas 1 to generate high-temperature flue gas, the combustible gas 1 combustion furnace comprises a combustible gas 1 inlet, an oxygen-containing gas inlet and a high-temperature flue gas outlet, the outer wall of the biomass carbonization furnace comprises a jacket, the jacket comprises the flue gas inlet and the flue gas outlet for entering and e