| Since the 21 century,the energy situation has been very serious.Our country has constantly encouraged the development of new energy.Because of the energy characteristics of biomass resources,biomass resources have been placed in an important position in the future energy system.Biomass gasification technology can efficiently and quickly convert biomass raw materials into high-quality gas,at the same time,it is not limited by climate and regional factors,biomass energy will become the inevitable choice of national energy strategic security.In this paper,the rapid pyrolysis and steam experiments of biomass were carried out under a self-built gasification equipment,and the effects of particle size,gasification temperature and S/B ratio on the quality of gas production were studied.The results show that the particle size mainly affects the heating rate of biomass raw materials.the smaller the particle size is,the faster the heating rate of biomass raw materials is,so the higher the temperature is reached,and the better the quality of gas production is.Temperature is also the main factor affecting biomass gasification.With the increase of temperature,carbon conversion and gasification efficiency are increasing,at the same time,the calorific value of gas is getting lower and lower.The analysis may be that higher temperature will promote the water-gas reaction and methane reforming reaction,and reduce the content of CH4 and CO.The introduction of water vapor can promote carbon gasification reaction,water gas conversion reaction,methane reforming reaction,etc.,and can increase the content of H2 and CO components,but when the water vapor flux is too large,the temperature in the gasifier will decrease due to the low temperature of superheated steam.When the S/B ratio is 1.4,the carbon conversion and gasification efficiency reach the maximum,96%and 94%,respectively.On the basis of single tube experiment,a regenerative gasifier was designed and built through a factory.The effects of temperature and air equivalent ratio on biomass gasification process were studied.The results show that the calorific value of gas production and gasification efficiency can be increased by increasing temperature.With the increase of air equivalent ratio,the contents of combustible gases CH4,CO and H2decrease,and the gas production rate increases approximately linearly.The gasification efficiency is affected by both the calorific value of gas production and the gas production.When ER is 0.3,the highest calorific value of the prepared gas is 5.41 MJ/m3（reaction temperature 1035℃）and 5.17 MJ/m3（reaction temperature 941℃）,respectively,in ER=0.3.When the temperature is 1035℃,the steam gasification experiment is carried out,The calorific value of gas production is 13.35 MJ/m3 and the hydrogen content is 30%.The side of the gasifier reflects the good heat storage performance of the regenerative gasifier and the feasibility of the whole demonstration device.A biomass gasification model was established based on Ansys14.5 software.The simulation results show that the gas-solid two-phase mixture is uniform in the gasifier during biomass gasification.With the increase of temperature,the gas production rate,carbon conversion rate and gasification efficiency increase continuously,but at high temperature,Temperature has little effect on the calorific value of gas production.With the increase of water vapor flux,the temperature in the gasifier will be affected,and the water-gas reaction and CH4 reforming reaction will also be affected,and then the gas-producing components,carbon conversion and gasification efficiency will be affected. |
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