Straw Pyrolysis Charcoal Gas Co-Production Of Pyrolysis Tar Spray Quality Optimization Research

Pyrolysis tar is one of the liquid fuels converted from biomass resources such as straw waste through pyrolysis technology.It is an inevitable by-product of biomass pyrolysis gasification and pyrolysis carbonization to generate combustible gas and coke.As an alternative to petroleum for energy supply,it has the advantages of being clean and renewable.However,pyrolysis tar has special physical and chemical properties and cannot be directly used in existing atomization equipment.At present,there are few researches on pyrolysis tar atomization technology,and the lack of mature atomization combustion equipment in the market hinders the development of technology.Based on this,this article carried out a number of experiments to study the spray characteristics and quality of pyrolysis tar.This article first clarifies the mechanism of pyrolysis tar atomization,explores the factors affecting atomization and the current research status of pyrolysis tar atomization technology at home and abroad.Based on this,the pyrolysis tar atomization process route was designed and the pyrolysis tar atomization test platform was built.Aiming at the problems of high viscosity of pyrolysis tar and poor atomization effect,the optimization test of high-efficiency atomization of pyrolysis tar was carried out.The effects of pyrolysis tar temperature,gas temperature,and gas pressure on the steady-state free spray particle size and particle size distribution of pyrolysis tar are comparatively studied.The results show that with the increase of pyrolysis tar temperature,air temperature and gas pressure,the The average diameter is continuously reduced and the uniformity of the size distribution is better.The order of the influence of each factor on the atomization effect is pyrolysis tar temperature,gas pressure,and gas temperature.The optimal atomization parameters are pyrolysis tar temperature 100℃,gas temperature 120℃,and air pressure 0.5MPa.In this working condition When the average diameter of the tar droplets is 81 um,the particles below 200 um account for more than 85%,and the uniformity of atomization is good.Carry out the modified pretreatment test of pyrolysis tar.The changes in composition and flow properties after tar pretreatment are comparatively studied.The results show that the addition of methanol affects the viscosity of the liquid through physical dilution,but does not affect the chemical reaction rate.With the increase of temperature and methanol addition ratio,the kinematic viscosity of pyrolysis tar decreases significantly.When the temperature exceeds 60°C,the rate of decrease of the kinematic viscosity becomes weak.Likewise,the rate of decrease decreases as the methanol ratio increases.At 40℃,when the methanol ratio is from 3% to 12%,the kinematic viscosity decreases by 90.0%,while at 80℃,the kinematic viscosity decreases by 75.0%.Adding methanol at low temperature has better effect on the fluidity of pyrolysis tar than at high temperature.Add methanol.The addition of methanol improves the low-temperature fluidity of pyrolysis tar,while the density and water content do not change significantly with the increase of methanol addition.Carry out atomization test of pyrolysis tar based on methanol modification.Taking the nozzle outlet as the coordinate origin and the spray axis as the Z axis,the atomization effect of pyrolysis tar after pretreatment on the Z=60cm plane was coupled and studied.The results show that methanol can significantly improve the atomization effect and the uniformity of droplet distribution.When there is no methanol,the influence of temperature on the atomization effect is greater than the atomization air pressure.As the proportion of methanol increases,the influence of temperature and atomization air pressure weakens,especially the influence of temperature.The addition of methanol has little effect on the atomization cone angle,which is mainly affected by the atomization pressure.The research results in this paper can provide valuable reference for optimizing the atomization parameters of pyrolysis tar,and provide data support for the combustion of pyrolysis tar.