水热处理对生物质成型炭理化性质的影响

棉秆(CS)及木屑(WS)经高压反应釜水热预处理后压制成型,并于固定床热解炉内进行炭化实验,利用电子万能材料试验机、热重分析仪等分析手段分析水热预处理对生物质成型炭的产率、物理性能(机械强度和表观密度)、热值及燃烧性能的影响。研究表明:随着水热温度的升高,生物质成型炭的产率增加且热值稳定,但燃烧性能变差;经水热预处理制得的生物质成型炭灰分产率均小于18%,固定碳产率均大于60%,满足欧标要求;随着水热温度的升高,生物质成型炭的表观密度及抗压强度均先增加后减小;对比所有实验样品,经230℃水热预处理制得的生物质成型炭(CS/WS-HT230-CB)物理性能及燃烧性能最佳,且均优于商用烧烤炭性能。

EFFECT OF HYDROTHERMAL TREATMENT ON PHYSICAL AND COMBUSTION PROPERTIES OF CHARCOAL BRIQUETTE PREPARED FROM BIOMASS WASTE

The biomass waste,cotton stalks(CS)and wood sawdust(WS),were pretreated by hydrothermal process using a high-pressure reactor and then the resulted biomass were densified and carbonized to prepare charcoal briquette using a fixed bed pyrolysis furnace. The effect of hydrothermal pretreatment on the yield,physical properties(mechanical strength and apparent density),calorific value and combustion characteristics of the resulted charcoal briquette were investigated by an electronic universal material testing machine and a thermogravimetric analyzer,etc. The results indicated that with the increasing hydrothermal temperature,the yield of the charcoal briquette increases and the calorific value remains stable,but the combustion characteristic becomes worse. The ash yield of the charcoal briquette prepared from the hydrothermal treated biomass is less than 18% and the fixed carbon yield is higher than 60%,which both meet the European standard. As the hydrothermal temperature increases,the apparent density and mechanical strength of the charcoal briquette increases initially and then decreases. CS/WS-HT230-CB showed the best physical properties and combustion characteristic among all the samples and their properties are higher than those of the commercial barbecue charcoal.