Experiment Study On Typical Biomass Pyrolysis And Gasification

With the development of human industrialized society,fossil energy is gradually depleted,and the harm to the environment caused by its utilization is becoming more and more serious.It is urgent to seek renewable and clean alternative energy.Biomass gasification hydrogen production can not only alleviate the energy crisis and reduce pollutant emissions,but also help my country to achieve the double-carbon goal,which is of great significance to the improvement of human survival and development environment.The hydrogen production method using steam as the gasification medium can obtain hydrogen-rich gas with high hydrogen content under normal pressure,which has high research value.This paper designs and builds a set of high-temperature tube furnace gasification test benches.Five typical biomass such as rice husk,wood chips,lignin,wheat straw,and corn stalk were selected for nitrogen pyrolysis,air gasification and steam gasification experiments.The temperature was 550℃,650℃,750℃,850℃,950℃.Explore the changes of typical biomass gasification products,calorific value and solid conversion rate with time and temperature.In typical biomass N₂ pyrolysis,with the increase of pyrolysis temperature,the H₂content gradually increases.At 950℃,the H₂ volume fraction reaches the maximum,the CH₄ content first increases and then decreases,the CO₂ content gradually decreases,and the CO content first decreases.After rising.Under different pyrolysis temperatures,the hydrogen production rate of wheat straw is the highest,the H₂volume fraction can reach49.4%at 950℃,and the hydrogen production rate of lignin is the lowest.The CH₄ volume fraction reaches the maximum at about 650℃,and the CH₄ volume fraction of corn stover can reach 26.1%.The calorific value of combustible gas reaches its maximum value at650℃,and the maximum value of wheat straw is 16593KJ/m3.The solid conversion rate shows an upward trend with the increase of pyrolysis temperature.The solid conversion rate gradually increased before 850°C,and did not change much from 850°C to 950°C.The solid conversion rate of wood chips is high,which can reach more than 80%.During the typical biomass air gasification,the volume fraction of H₂ increases with the increase of temperature,the hydrogen production rate of lignin is the highest,and the H₂ content reaches the highest 23.87%at 950℃.The volume fraction of CH₄ increased first and then decreased with the increase of temperature.The volume fraction of CH₄showed a turning point at about 750℃,and the volume fraction of CH₄ reached a maximum of 21.44%at 750℃.The calorific value of combustible gas reaches the maximum around 750°C.Therefore,when biomass is gasified in fixed-bed air,to prepare high-calorific value combustible gas,the temperature should be around 750°C.During steam gasification of typical biomass,the H₂ content rises first and then gradually increases with temperature.The gasification effect of typical biomass under water vapor atmosphere is significantly better than nitrogen pyrolysis and air gasification.At the same temperature,the H₂ content There is a substantial increase,and the H₂content of wood chips can reach 60.17%at 750°C.The content of CH₄ gradually decreases with the increase of temperature.The content of CO₂ first decreases and then changes little with the increase of temperature.The content of CO first decreases and then slightly increases with the increase of temperature.The calorific value of combustible gas reaches its maximum value at 650℃,and the solid conversion rate shows an upward trend with the increase of gasification temperature.In a typical biomass steam gasification process,the increase in the gasification temperature and the provision of a large amount of high-temperature steam can effectively reduce the CH₄ content,increase the volume fraction of H₂,and improve the H₂ yield in the typical biomass gasification products.Methods and ideas.