典型生物质及木质素水蒸气气化制富氢合成气的试验研究

Influence of Temperature on Gasification Products of Typical Biomass and Lignin Using Water Vapor

选取稻壳、木屑、小麦秸秆及玉米秸秆四种典型生物质及木质素,以管式炉为反应器,将每种实验样品3 g放入陶瓷方舟,通入0.4 MP、150℃的水蒸气,流量为3 g/min,选取550℃、650℃、750℃、850℃、950℃进行水蒸气气化实验,探究典型生物质水蒸气气化产物、热值及固体转化率随温度变化规律。实验结果表明:木屑产生H 2含量在750℃可达60.17%。提高水蒸气气化温度可以有效降低CH 4含量,提高H 2的体积分数。在实际工程应用时,如果要获得较高的氢气纯度,温度至少在750℃以上;如果使可燃气含量最高时,建议将温度控制在750℃左右。

As global warming becomes more serious and energy demand continues to grow,it is crucial to seek sustainable and zero-carbon energy sources.Biomass energy is directly or indirectly derived from the photosynthesis of green plants and stores solar energy in the form of chemical energy.It is an important energy carrier and the only renewable carbon resource.It has the unique advantages of being renewable,environmentally friendly,clean and low-carbon,and closely links energy,materials,and chemicals in various forms such as solid,liquid,and gas,and is widely used in many fields such as industry,agriculture,transportation,and life field.The development of biomass energy in the modern energy system is not only conducive to promoting the large-scale development of agriculture,but also plays a positive role in coping with climate change,energy shortage and environmental pollution.Hydrogen production from biomass gasification can effectively alleviate the shortage of fossil energy,because hydrogen energy is a clean energy,and the combustion product is only water.More importantly,the entire life cycle of biomass remains carbon-neutral,so hydrogen production from biomass gasification will be important research direction.The difficulty in hydrogen production from biomass gasification lies in how to increase the hydrogen conversion rate.Using high-temperature steam as the biomass gasification medium provides a source of hydrogen for the gasification reaction,which can effectively increase the yield of hydrogen after gasification.Therefore,four typical biomasses of rice husk,sawdust,wheat straw,corn straw and lignin,were selected in this paper.Using a tube furnace as a reactor,3g of each experimental sample was put into a ceramic ark,and 0.4 MP,150℃water vapor,with a flow rate of 3g/min,selected 550℃,650℃,750℃,850℃,and 950℃for steam gasification experiments to explore the changes in typical biomass steam gasification products,calorific value and solid conversion rate with temperature law.The experimental results show that when the typical biomass is gasified with water vapor,the H 2 content increases firstly and then gradually increases with the increase of temperature,and the H 2 content of wood chips can reach 60.17%at 750℃.The content of CH 4 decreased gradually with the increase of temperature,the content of CO decreased firstly and then slightly increased with the increase of temperature,and the content of CO 2 decreased first and then changed little with the increase of temperature.The calorific value of gas showed a trend of first increasing and then decreasing with the increase of reaction temperature.The solid conversion rate increases rapidly with the increase of gasification temperature and then tends to be stable.Increasing the gasification temperature of water vapor can effectively reduce the content of CH 4 and increase the volume fraction of H 2.In practical industry applications,if you want to obtain higher hydrogen purity,the temperature should be at least above 750℃;if you want to maximize the combustible gas content,it is recommended to control the temperature at about 750℃.The results of this paper provide fundamental data for subsequent industry applications.