THE EFFECT OF FUSION TEMPERATURE, AGING TIME AND AGING TEMPERATURE TO THE WATER ADSORBENT SYNTHESIZED FROM SPENT BLEACHING EARTH TO PURIFY ETHANOL-WATER MIXTURE

Water adsorbent to dehydrate water ethanol mixture was synthesized from spent bleaching earth (SBE) using modified fusion method. The SBE was regenerated by heat at 750C. Alumina (Al2O3) was added to SBE with 80 g alumina per 100 g SBE. Potassium hydroxide (KOH) was added to SBE with stoichiometry ratio of KOH: SBE of 1.1 then mixed and fused at temperature 650C and 550C for 12 hours in a furnace. The fused mixture was grounded and mixed with water at 65 g H2O per 100 g SBE. This mixture was aged at 60C and 80C in an oven before crystallization took place in 5 parts by weight 5% KOH for 48 hours. The product obtained was washed 3 times with distilled water using filtration set and dried in oven at 220C for 20 hours. Full multilevel factorial experiments were carried out. Analysis of the results by using Minitab Release 14 Statistical software revealed that the main effect of fusion temperature and aging time was significant. The analysis also showed that there was significant interaction effect of fusion temperature to aging time and aging temperature. The best conditions to synthesize the water adsorbent were: 550°C of fusion temperature, 80°C of aging temperature and 3 days of aging time with water uptake of 0.0353 g H2O / g water adsorbent, approximately to 84% of commercialized of zeolite 3A.

本研究以废弃漂白土（spent bleaching earth, SBE）为原料，采用改性熔融法合成了用于脱水水乙醇混合物的吸水剂。首先将废弃漂白土置于750℃下焙烧再生；按每100g废弃漂白土添加80g氧化铝（Al₂O₃）的比例向其中加入氧化铝，再按氢氧化钾（KOH）与废弃漂白土的化学计量比1.1的比例添加KOH，混合均匀后置于马弗炉中，分别在650℃与550℃下熔融12小时。将熔融产物研磨后，按每100g废弃漂白土添加65g蒸馏水的比例与水混合，将该混合物置于烘箱中分别于60℃与80℃下陈化，随后加入5倍质量的5%KOH溶液中进行48小时的晶化反应。所得产物采用过滤装置用蒸馏水洗涤3次后，置于烘箱中220℃下干燥20小时。

本研究开展了全因子多水平析因实验，采用Minitab Release 14统计软件对实验结果进行分析，结果显示：熔融温度与陈化时间的主效应显著，且熔融温度与陈化温度、陈化时间之间的交互效应同样显著。合成该吸水剂的最优工艺条件为：熔融温度550℃、陈化温度80℃、陈化时间3天，此时吸水倍率可达0.0353 g H₂O/g吸水剂，约为商业化3A沸石（zeolite 3A）吸附性能的84%。