Study On Gasification Characteristics Of Straw Particles Catalyzed By Brown Gas Under Oxygen-Enriched Conditions

As an important alternative energy source for fossil fuels,biomass energy has been rapidly developed and widely used worldwide in recent years.Biomass gasification technology is one of the main ways to utilize biomass energy.It uses thermochemical conversion technology to convert biomass with low utilization efficiency into combustible gas with high utilization efficiency.Oxygen-enriched gasification is a method of gasification technology,which can significantly reduce the content of inert gas N₂ in the gasification process,increase the calorific value of gas and reduce the volume of gasification agent,but the cost is high.Brown gas is a mixture of hydrogen and oxygen produced by water electrolysis,which is doped with trace amounts of active groups(OH^-,O^2-,H⁺)and water molecules（H₂O）.It is an excellent catalyst and combustion promoter.Therefore,this thesis studies the characteristics of brown gas catalyzed straw gasification under oxygen-rich conditions,which provides technical reference for obtaining medium and high calorific value biomass gasification gas for industrial application,further improving biomass gasification efficiency and reducing oxygen-rich gasification cost.It is of great significance for efficient and clean utilization of biomass under the goal of’double carbon’.In this thesis,Brown gas（HHO）was used as a catalyst to study its effect on biomass gasification characteristics under oxygen-rich conditions.The oxygen-rich atmosphere conditions of 21%,30%,40%and 50%oxygen volume concentration were set up by oxygen tank,and straw was used as raw material.Micro-gasification experiments were carried out on a tube furnace.Firstly,the experimental device was designed and built.The experimental platform was composed of gas distribution system,reaction system and analysis system.Secondly,the raw materials were analyzed by elemental analysis,industrial analysis and thermogravimetric analysis to determine the experimental parameters.Finally,straw gasification experiments were carried out under different working conditions.The experimental results are as follows:（1）With the increase of oxygen concentration,the temperature range of each gas has no obvious change,but the peak value has obvious change.The peak content of CO at 21%,30%,40%and 50%oxygen concentration is 2.87%,3.48%,3.96%and 4.24%,respectively.The peak contents of CO₂ were 4.78%,6.43%,6.86%and 6.54%,respectively.There was no H₂produced under air condition,and trace H₂ appeared under other oxygen-rich conditions,but the content was small and did not change with the increase of oxygen concentration.The methane precipitation time is short and the peak content increases slightly with the increase of oxygen concentration.（2）After the introduction of Brown gas（HHO）,the time of occurrence of carbon monoxide in all working conditions will be delayed,and the peak value will be reduced,but the carbon monoxide precipitation time will become longer,and the content of carbon dioxide will decrease slightly.The decrease of carbon dioxide content indicates that Brown gas promotes the reduction reaction,and methane has a longer precipitation time than that without Brown gas.The addition of Brown gas effectively controls the growth trend of carbon dioxide when the temperature rises,improves the quality of gas,and also has the catalytic effect of making tar easier to crack into combustible gases such as methane.