丙酮一步法生产MIBK装置的副产物精馏分离研究

针对丙酮一步法生产MIBK装置的副产物（丙酮、异丙醇、水、MIBK混合物）,采用间歇精馏分离得到纯度〉98％的丙酮、纯度〉99％的异丙醇和水恒沸物、纯度〉90％的MIBK。对分离得到的纯度〉99％的异丙醇和水恒沸物用乙二醇作为萃取剂进行萃取精馏分离得到纯度99．5％异丙醇,同时减压精馏回收乙二醇。     

Isopropyl alcohol: an unusual, powerful, ‘green’ solvent for the preparation of silicone–urea copolymers with high urea contents

Isopropyl alcohol (IPA) is used as the reaction solvent for the preparation of silicone–urea copolymers. Reactivity of isopropanol with bis(4-isocyanatocyclohexyl)methane (HMDI) was investigated at 23 °C using infrared spectroscopy. Spectroscopic studies indicated very low reactivity of IPA towards HMDI at 23 °C. High molecular weight segmented silicone–urea copolymers were prepared through the reaction of HMDI with aminopropyl and N-methylaminopropyl terminated polydimethylsiloxane (PDMS) oligomers and three different chain extenders, ethylene diamine (ED), hexamethylene diamine (HMDA) and 2-methyl-1,5-diaminopentane (Dytek A). Number average molecular weights of PDMS oligomers varied between 900 and 7000 g/mol, respectively. Reactions were carried out at room temperature in IPA. Silicone–urea copolymers with urea hard segment content between 10 and 42% by weight were prepared. Thermal and mechanical characterization of the copolymers indicated the formation of microphase-separated systems with excellent tensile strengths. Interestingly, structure of the diamine chain extender did not show any influence on the mechanical properties of the homologous series of silicone–urea copolymers.     

Gold stripping by hydro-alcoholic solutions from activated carbon: Experimental results and data analysis by a semi-empirical model

The aim of this work was to study gold stripping from activated carbon using a range of different alcohols (isopropanol, ethanol and ethylene glycol). The experimental work was carried out on a laboratory scale, using activated coconut carbon, at 40 to 80 °C and up to 8 h extraction time. Isopropanol was the most rapid eluent with > 98% Au eluted after 1 h at 80 °C, ethylene glycol had a similar extraction after 2 h, ethanol was the least effective with 5 h required for > 95% extraction. Interestingly, 77% Au extraction was obtained at 40 °C using ethylene glycol.     

Highly active Cu-based catalysts on carbon nanofibers for isopropanol dehydrogenation

Cu/CNF and Cu/CeO₂/CNF catalysts have been synthesized and characterized on different nanostructured carbon nanofibers (CNF). The samples have been tested in isopropanol dehydrogenation. Cu/CNF show similar activity to Cu catalysts supported on activated carbon. Cu/CeO₂ nanotubes have been synthesized on the CNF surfaces. The Cu/CeO₂ nanotubes exhibit much higher activity and lower activation energy than Cu/CNF. The selectivity towards acetone depends on the fraction of CeO₂ in the composites. High activity and selectivity has been achieved with a Cu₁₂Ce₅/CNF catalyst.     

金属离子Al~(3+)对SBA-15分子筛形貌的调控作用研究

以异丙醇铝为铝源,在高浓度酸性环境下,通过Al3+调控SBA-15的形貌与性质。在强酸条件下,所得样品的实际n(Si)∶n(Al)都远高于配料n(Si)∶n(Al),且样品的Brnsted酸为0,Lewis酸也较低,铝元素无论是以嫁接还是骨架配位形式都难以嵌入到SBA-15的体相中。随着配料n(Si)∶n(Al)降低,SBA-15由线粒状向端粒颗粒状发展;当配料n(Si)∶n(Al)=5和2.5时,SBA-15仍然具有有序结构,但是二维有序性不强。当n(Si)∶n(Al)=20时,所得材料具有最高的比表面积、孔容及孔径,其值分别为827m2/g,1.25cm3/g,6.06nm。无机硅物种和有机高分子表面活性剂相互作用及体系Al3+浓度导致的胶束空间限制这两方面是Al3+对SBA-15的形貌形成的原因。     

Effectiveness factor of isopropanol oxidation on IrO2 based electrodes of different loading

The influence of IrO₂ loading on the effectiveness factor E_f of the electrochemical oxidation of isopropanol was investigated. A model has been proposed based on three main reactions: electrochemical IrO₂ oxidation to IrO₃, chemical oxidation of the organic compound via IrO₃ and O₂ evolution via decomposition of IrO₃. It has been found that the relative effectiveness factor E_f for the electrochemical oxidation of IrO₂ to IrO₃ is loading independent contrary to the chemical reaction which decreases with increasing IrO₂ loading.     

Pervaporative Dehydration of Organic Solvents

Abstract

Pervaporative separation of acetone/water and isopropanol (IPA)/water systems has been studied in the water-lean range of composition of the feed mixtures. Poly(vinyl alcohol) (PVA) membranes crosslinked with citric acid, adipic acid, maleic acid, glutaraldehyde, and glyoxal were used for this purpose. The sorption characteristics of all the membranes indicate that these membranes have a good sorption selectivity for water in view of the hydrophilic nature of PVA. The type of crosslinker used for crosslinking has been shown to have an important bearing on the permeation characteristics of the membranes. Thus, the trifunctional citric acid yields the highest selectivity but lowest flux. A comparison of the productive capacities of the various membranes indicates that the glutaraldehyde crosslinked membrane has the maximum productive capacity for IPA dehydration whereas maleic acid crosslinked membrane yields the highest productive capacity for acetone dehydration.     

Experimental study of isopropanol dehydrogenation over amorphous alloy raney nickel catalysts

The dehydrogenation reaction of isopropanol occurring at low temperature is of great industrial importance. It is a key procedure in isopropanol/acetone/hydrogen chemical heat pump system. An experimental investigation was performed to study the behavior of the liquid phase dehydrogenation of isopropanol over amorphous alloy Raney nickel catalysts. Un-promoted and promoted catalysts were used and their performances were compared under various catalyst amounts, acetone content in the reactant and reaction temperature ranging from 348 K to 355 K. It is found that there exists an optimum catalyst concentration which is about 0.34 g in 300 ml isopropanol. The temperature has evident effect on the reaction. The presence of activities of Fe-promoted catalyst decrease slightly compared to the un-promoted catalyst when the temperature are 348 K and 351 K. Besides, the reaction rate de- creases almost linearly with the increase of acetone volume fraction in the reactant.     

Xanthan Precipitation from Solutions and Fermentation Broths

Abstract

Precipitation of xanthan from solutions and fermentation broths is studied. The effects of different precipitating agents, initial xanthan concentrations, and salt additions on xanthan solutions are examined. The effect of sodium and calcium chloride concentrations added to isopropanol (IPA) is studied for xanthan solutions. Xanthan precipitation from fermentation broths has been carried out, and the effect of salt addition to IPA is considered.     

Steam flow measurement using alcohol tracers

Tracer flow testing procedures are increasingly being used for routine measurement of well output in operating geothermal fields. A new procedure developed in New Zealand uses low boiling-point, liquid alcohol (isopropanol or butan-2-ol) as the steam-phase tracer. The use of alcohol tracers allows major simplifications to field procedures, including injection with conventional liquid-dosing pumps, sampling into open sample bottles and preparation of composite steam/water tracers. These practical benefits far outweigh the only drawback of alcohol tracers, which is the need to correct for alcohol gas dissolved in the liquid phase. This paper reviews development work with alcohol tracers over the past five years and discusses the properties of alcohols and the practical aspects of their use in tracer-dilution testing.