固体酸催化下玉米芯在近临界甲醇-环己烷中的液化研究

摘要

通过共沉淀法和浸渍法制备了SO2-4/TiO2-ZrO2固体酸催化剂,并采用傅里叶红外光谱(FT-IR)、X射线能谱(EDX)和氮气吸附-脱附分析等手段对催化剂进行表征,考察了溶剂配比、反应温度、反应停留时间和催化剂用量对玉米芯在近临界甲醇-环己烷中液化转化率的影响,并利用FT-IR和气相色谱-质谱联用仪(GC-MS)对玉米芯液化产物进行了分析.结果表明:SO2-4成功地负载到TiO2-ZrO2上,且SO2-4/TiO2-ZrO2属于介孔材料;玉米芯的最佳催化液化条件为V(甲醇):V(环己烷)=2:1,反应温度250℃,反应停留时间1.5 h,催化剂用量(以玉米芯质量计)4％,玉米芯与溶剂的固液比为1:15(g:mL),此条件下液化转化率为76.67％.FT-IR和GC-MS分析表明玉米芯液化产物主要成分为酚类和酯类化合物.%SO2-4 /TiO2-ZrO2 solid acid catalyst was prepared by co-precipitation and impregnation. The catalysts were characterized by Fourier transform infrared spectrometer ( FT-IR ) , energy dispersive X-ray spectrometer ( EDS ) and nitrogen physisorption. The effects of solvent ratio, reaction temperature, reaction time and catalyst dosage on corncob conversion were investigated. The chemical compositions of liquefaction production with and without catalysts were determined by FT-IR and gas chromatography/mass spectrometry(GC-MS). The results indicated that SO2-4 was successfully loaded on the TiO2-ZrO2 and SO2-4 /TiO2-ZrO2 was a mesoporous material. The optimal conditions of liquefaction were 1 g corncob with 4% SO2-4 /TiO2-ZrO2 at 250 ℃ for 1. 5 h when the volume ratio of methanol to cyclohexane was 2 and the solid-liquid ratio of corncob and solution was 1:15 ( g : mL ) , under which the liquefied rate reached the maximum of 76. 67%. The main components of the liquefaction product were phenols and ester compounds.