| The conversion and utilization of biomass energy is an effective solution to the current shortage of fossil energy.China,as an agricultural country with a large population,has rich annual production of corn stalks,but its energy utilization rate is relatively low.Solid waste disposal is difficult and it is easy to pollute the environment and even harmful to human healthy.As the current research focus,the promising pyrolysis technology can convert the energy contained in biomass such as corn straw and solid waste into a wide range of widely used tri-state products,including biochar,bio-oil,and pyrolysis gas,which can effectively recover energy,avoid pollution on the environment as well as utilize biomass energy by high-value ways.The pyrolysis characteristics of corn stalk and solid waste materials(fungi residues,sludge and leather waste)were investigated at different temperatures of 400?,500?,600?,700? and 800?.The main indicators include tri-state product results,gas composition,gas calorific value,and system mass balance.The influence of each component removed during pretreatment separation was also analyzed.The raw materials were characterized by OEA,FT-IR,SEM and TGA.The bio-char was characterized by SEM.The main conclusions are shown as follows:(1)During the pyrolysis process,as the temperature increases,the carbon yield gradually decreases;the bio-oil quality,gas volume,and gas quality gradually increase,and more bio-oil is produced within the temperature range of 400? to 500?;In the temperature range of 600?-700?,the volume of gas produced by corn stalk components grows obviously,and the solid waste raw materials' gas volume increase obviously in the temperature range between 500?-800?.(2)The lignin produced the most charcoal.Between 37.08%and 59.71%,the amount of carbon produced by cellulose was the lowest,and it was 12.57%at 800?.The cellulose produced the most oil,and it was between 43.93%and 46.7%.The lignin produced the least amount of oil.The minimum was 21.58%at 400?;in the composition of gas production,lignin pruduced more H2 and CH4,H2 reached a maximum content of 32.94%at 800?,and CH4 reached a maximum content of 31.15%at 500°C;CO2 production in hemicellulose pyrolysis gas was the highest;the highest volume fraction of CO was produced by cellulose pyrolysis.Different raw materials all showed the highest calorific value at 700?,and the highest calorific value of lignin in the component corn stalk raw materials was 3631.75 kcal/Nm3.Holocellulose produced more CO2,and the minimum gas calorific value was 2651.7 kcal/Nm3.The maximum calorific value of gas produced by the waste raw materials was 3779.6 kcal/Nm3.Because of the large amount of impurities in the composition,the minimum calorific value of the sludge pyrolysis gas was 2763.61 kcal/Nm3.In terms of calorific value,the fungi residues is higher than lignin,so pyrolysis is an important project implementation method for solid waste treatment.The experimental system had good system mass balance results.The increase in temperature helped to reduce system quality loss.The experimental device can be scaled up to the scale of industrial operation.(3)Extracts didn't affect the characteristics of results,mainly to increase the yield of corn stalk raw material biochar and the calorific value of gas produced by ethanol-treated corn stalk.The removal of lignin affected the volume fraction of CH4 and the calorific value of gas.At 700?,the content of CH4 decreased by 2.67%and the calorific value decreased by 300.19 kcal/Nm3;the removal of hemicellulose mainly affected the CO2 content and the calorific value of gas,due to the existence of CO2,homocellulose produced the lowest calorific value gas.(4)The main pyrolysis temperature range of corn stalk components in this work were shown as follows:hemicellulose was 201?-294?,cellulose was 285?-375?,lignin was 230?-535?;the solid waste raw material pyrolyzed during a wide temperature range which was 185?-525?. |
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