催化剂分段装填多孔质膜反应器的实验研究

提出一种新型双重圆管膜反应器结构,其中内管采用Vycor玻璃膜。为了增加膜面积,同时减轻扩散阻力,改善氢的透过性,催化剂不是充满环隙而是在膜的两端反应器的环隙中分段填充。以异丙醇脱氢生成丙酮为反应体系,在低温范围(150～200℃)对这种结构进行了实验研究。结果表明,反应转化率不仅较之环隙内充满催化剂的传统膜反应器有了很大提高,而且还大幅度突破了平衡转化率。     

pH-metric determination of acid values in vegetable oils without titration

A new method for determining acid values in vegetable oils has been developed for a nontitration pH-metric technique with a reagent consisting of 0.20 M triethanolamine in a 1∶1 solution of water and isopropanol. The emulsive properties of this reagent provide rapid (within a minute) and quantitative extraction of free fatty acids from an oil into the solvent phase. Acid values were determined by measuring conditional pH of the emulsified reagent in a pH-meter with an aqueous reference electrode. Three different applications of this technique are discussed.     

Pervaporation separation of water/isopropanol mixtures through crosslinked carboxymethyl chitosan/polysulfone hollow‐fiber composite membranes

Carboxymethyl chitosan (CMCS)/polysulfone (PS) hollow‐fiber composite membranes were prepared through glutaraldehyde (GA) as the crosslinking agent and PS hollow‐fiber ultrafiltration membrane as the support. The permeation and separation characteristics for dehydration of isopropanol were investigated by the pervaporation method. Pure chitosan, carboxymethyl chitosan, and crosslinked carboxymethyl chitosan membranes were characterized by Fourier transform infrared (FT‐IR) spectroscopy and X‐ray diffraction (XRD) to study the crosslinking reaction mechanism and degree of crystallinity, respectively. The effects of feed composition, crosslinking agent, membrane thickness, and feed temperature on membrane performance were investigated. The results show that the crosslinked CMCS/PS hollow‐fiber composite membranes possess high selectivity and promising permeability. The permeation flux and separation factor for isopropanol/water is 38.6 g/m²h and 3238.5, using 87.5 wt % isopropanol concentration at 45°C, respectively. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1959–1965, 2007     

萃取-恒沸精馏联合流程用于异丙醇-水分离的节能研究

针对现有的恒沸精馏法生产工艺能耗较大的缺点,将萃取—恒沸精馏联合流程用于异丙醇-水的分离工艺并提出了改造方案。对新工艺进行实验研究表明,原料进入提浓塔并保持回流比0 6以上,其塔顶产物进入V(原料)∶V(萃取剂)∶V(分离剂)=1∶2 5∶1的萃取塔进行萃取,萃取相通过脱水塔可以从塔底得到合格异丙醇产品,塔顶恒沸物冷凝分相后,有机层大部分作为萃取剂重新使用,萃余相通过浓缩器回收得到分离剂溶液。根据实验研究结果进行的模拟计算表明,新工艺比原工艺节约能耗40%。     

Modified poly(vinyl alcohol)/chitosan blended membranes for isopropanol dehydration via pervaporation: Synthesis optimization and modeling by response surface methodology

Box–Behnken (BB) design of response surface methodology (RSM) was effectively applied to optimize fabrication conditions of modified poly(vinyl alcohol) (PVA) and chitosan (CS) blended pervaporation (PV) membranes. The PVA/CS membranes were crosslinked either by chemical reaction with glutaraldehyde (GA) or by heat‐treating at different temperatures. The main objectives were to determine the optimal levels of fabricating parameters and also to investigate interactions among the variables. CS content in the blended membranes, concentration of crosslinking agent and heat‐treating temperature were the fabrication parameters, the main effects and interaction effects of which on membrane structure and PV performance toward isopropanol (IPA)/water dehydration were investigated, and for which regression models were established. The modified PVA/CS blended membranes were characterized by means of scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) as well as X‐ray diffraction (XRD). It was found that the CS content is the most significant factor influencing flux and separation factor among the three studied variables and the experimental results are in excellent accordance with predicted values from the developed RSM regression models. The RSM results indicated that under preparation conditions of 80 wt % CS in the blended membrane, 0.58 wt % GA concentration, and 77 °C heat‐treating temperature, the maximum separation factor of 5222.8 and the normalized flux of 9.407 kg µm/m²h can be acquired with feed content of 85 wt % IPA at 25 °C, showing that the prepared membrane is highly efficient for PV dehydration of IPA. The models were satisfactorily validated against experimental data. Furthermore, the optimum membrane presents excellent separation performance at different feed compositions and temperatures. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44587.     

Conversion of carbohydrates into 5‐hydroxymethylfurfural in a green reaction system of CO2‐water‐isopropanol

In this work, a green reaction system of CO₂‐water‐isopropanol was developed for 5‐hydroxymethylfurfural (HMF) production. The conversion of fructose in a CO₂‐water system was first investigated, and the results showed this system could promote the formation of HMF compared to a pure water system. Then, isopropanol was introduced into the CO₂‐water system and the HMF formation became better because the solvent effect of isopropanol increased the tautomeric composition of fructofuranose, which was easy to form HMF. The existence of isopropanol was found to greatly suppress secondary reactions where HMF was converted to levulinic acid and insoluble humin. Meanwhile, the effects of reaction parameters on the conversion of fructose to HMF in the CO₂‐water‐isopropanol system were analyzed, and a high HMF yield of 67.14% was obtained. Finally, to further illustrate the merits of CO₂‐water‐isopropanol system, productions of HMF from other carbohydrates were tested and satisfactory yields were achieved. © 2016 American Institute of Chemical Engineers AIChE J, 63: 257–265, 2017     

典型燃煤电厂浆液冷却烟气消白设施SO3治理效果测试研究

分别采用控制冷凝法和异丙醇吸收法对某1 000 MW燃煤发电机组浆液冷却烟气消白设施的烟气SO₃控制效果开展测试。结果表明,机组烟气湿法脱硫设施对SO₃去除效率为62.50%（控制冷凝法）和64.63%（异丙醇吸收法）。烟气经现有超低排放设施协同治理后SO₃质量浓度低于3 mg/m³。浆液冷却设施对SO₃的去除效率仅为6.68%（控制冷凝法）和5.55%（异丙醇吸收法）,烟气SO₃控制效果和环境效益相对较低。建议基于科学论证审慎实施燃煤电厂烟气消白工作,应进一步开展高效SO₃治理技术、测试标准和环境管理政策研究。     

用超临界异丙醇流体制备TiO2/活性炭复合材料

在存在超临界异丙醇介质的条件下,将钛酸异丙酯与活性炭反应生成具有光催化与吸附性能协同效应的TiO2/活性炭复合材料.产生协同效应,可使低浓度污染物快速地表面富集和吸附净化,加快了污染物的光催化降解速率,TiO2的光催化作用又促使被活性炭吸附的污染物向TiO2表面迁移,使活性炭吸附能力得以恢复,实现了吸附剂的原位再生.     

异丙醇一步法合成MIBK精馏过程优化

用PROII过程模拟软件对异丙醇一步法合成甲基异丁基酮(MIBK)的精馏系统进行了分析和模拟优化,提出了5塔流程的改进工艺,使MIBK的回收率提高了2.8倍,达到91·7%,而且再沸器能耗由12·79t水蒸气/t产品降低到8·27t水蒸气/t产品。还建立了普通精馏塔和萃取精馏塔小试实验装置,对全工艺流程逐塔进行热态研究,验证了其工业可行性。     

氯化铁催化合成氯乙酸异丙酯

以氯乙酸和异丙醇为原料,三氯化铁为催化剂,合成了乙酸异丙酯。结果表明,氯化铁的催化活性良好,氯乙酸异丙酯产率达率可达８６．４％。