超临界CO2流体萃取蚕蛹油研究

在8kg.h-1CO2流量下探讨了蚕蛹油的超临界CO2萃取。在单因素实验的基础上通过正交实验确定了蚕蛹油的较佳萃取条件。实验结果表明,萃取温度对蚕蛹油得率影响较大,其次是萃取时间、萃取压力。超临界CO2萃取蚕蛹油的较优条件为:温度50℃,压力25MPa,时间2.5h,在上述条件下蚕蛹油得率为29.45%。     

超临界CO_2和乙酸乙酯提取胆红素

利用超临界CO2和乙酸乙酯萃取技术,探索从猪胆汁中提取胆红素而不产生氯仿废水的工艺。胆汁经皂化,喷雾干燥,超临界CO2萃取去除脂类杂质,乙酸乙酯回流浸提、精制,得胆红素。超临界CO2脱脂最佳工艺条件为:萃取压力35 MPa,温度50℃,CO2流量30 kg/h,时间3 h;乙酸乙酯回流提取最佳条件:m(胆汁粉)∶m(提取液)=1∶80,时间2.5 h,温度88℃,m(亚硫酸氢钠)∶m(提取液)=1∶50,酸化pH=4.0。该工艺与传统工艺相比,不仅胆红素得率由0.048%提高到0.059%,其质量分数也由89.6%提高到94.2%,避免了有毒氯仿废液的产生,废液排放量为0,实现了胆红素的无污染生产。     

含夹带剂超临界CO2萃取芝麻油

利用含夹带剂超临界CO2从芝麻中萃取了芝麻油,实验研究了萃取压力、温度、时间、CO2流量等工艺条件因素对萃取率的影响。研究结果表明:萃取率随着压力升高而升高;温度在45℃以下时,萃取率随着温度对升高而升高,但当温度超过45℃以后,萃取率略有下降;萃取率随着时间的增加而增加,但随着时间的延长,萃取率的增加幅度逐渐变缓;随CO2流量增大,萃取率上升。得到超临界CO2流体萃取芝麻油的较优工艺条件为:萃取压力为30 MPa、萃取温度45℃、萃取时间180 min、CO2流量10 kg/h。     

超临界CO2萃取黑胡椒中有效成分的研究

用超临界CO2萃取技术,首先在低压、低温的条件下选择性萃取黑胡椒精油,进而在高温、高压及极性夹带剂的协同作用下,萃取富含胡椒碱的黑胡椒油树脂。另外,利用分子蒸馏技术纯化超临界CO2萃取的黑胡椒精油,得到适用于日化行业的无色、无辛辣感的挥发油,并通过GC-MS对比分析其香气成分。研究结果表明,超临界CO2萃取黑胡椒精油的较优条件为:萃取压力10MPa、萃取温度35℃、萃取时间1.5h,在该条件下产物得率为3.01%;超临界CO2萃取黑胡椒油树脂的最佳条件为:m(原料)∶m(体积分数95%食用乙醇)=2∶1、萃取压力30MPa、萃取温度50℃、萃取时间4h,在该条件下油树脂得率为7.88%,油树脂中胡椒碱质量分数为65.79%。     

CO2超临界萃取叶黄素工艺条件的优化控制

采用超临界CO2提取方法探讨了从万寿菊中提取叶黄素的最佳工艺条件.通过单因素和正交实验确定影响叶黄素萃取的因素为:时间>温度>压力>CO2流量;优化工艺条件为:萃取时间3h,萃取压力25MPa,温度55℃,CO2流量10L·h-1,分离罐Ⅰ温度42℃,压力11MPa,分离罐Ⅱ温度38℃,压力同储罐.在该优化工艺条件下,...     

超临界CO2流体萃取中华雪胆中齐墩果酸的研究

采用正交实验优化中华雪胆中齐墩果酸的萃取工艺条件,考察了萃取压力、温度、时间、CO2流量、夹带剂种类及用量对萃取率的影响,确定了超临界CO2流体萃取中华雪胆中齐墩果酸的最佳条件如下:萃取压力40 MPa,萃取温度55℃,无水乙醇为夹带剂,用量为5%,萃取时间为2 h,CO2流量为20kg·h1.与传统有机溶剂提取法相比,用超临界CO2流体萃取齐墩果酸,不仅方法简便、安全,而且提取的选择性与效率更高.     

籽瓜中提取果胶的工艺研究

采用萃取方法从籽瓜中提取果胶,通过温度、pH值、萃取时间、浸提比(籽瓜质量与水质量之比)4个工艺参数对果胶收率作正交实验,得到的较优的工艺操作条件为:温度为85℃,pH值2.5;萃取时间2h,浸提比1∶1,果胶产率14.1%。     

超临界二氧化碳萃取腐竹中脂类物质的研究

采用超临界CO2萃取技术分离腐竹中的脂类物质,以脱油率为考察指标,研究了萃取压力、萃取温度对萃取最终脱油率的影响,并确定了超临界CO2流体萃取腐竹中脂类物质最佳工艺条件：萃取压力35 MPa,萃取温度45℃,分离温度30℃,萃取时间1.5 h,此工艺条件下出油率为4.79%。     

超声强化超临界CO_2萃取葵粕绿原酸工艺

绿原酸具有抗氧化、清除自由基、抑制突变与抗肿瘤等生理活性。考察了萃取温度、压力、时间、流体流量和超声功率密度对超声超临界CO2萃取绿原酸的影响,结果表明,超声波的加入可以缩短超临界CO2萃取时间、降低CO2流量和提高萃取率。工艺优化后的条件为:70%乙醇加入量为400mL/100g原料,萃取温度、压力、时间、CO2流量分别为50℃、30MPa、3.5h、3.0L/h,超声频率和功率密度分别为20kHz、100W/L。优化条件下绿原酸的萃取率达4.71%     

超临界CO_2萃取蜂蜡中的高级脂肪醇

蜂蜡高压皂化水解后用超临界CO2萃取制得高级脂肪醇。最佳皂化条件为:皂化温度150℃,皂化时间4 h;超临界CO2萃取的最佳条件为:萃取温度60℃,压力25 MPa,时间2 h。高级脂肪醇的得率为63.11%。     

乙烯酮(双乙烯酮)下游产品废水的治理技术

乙烯酮(双乙烯酮)是十分重要的化工中间体,其下游产品较多。江苏某化工厂开发生产乙烯酮(双乙烯酮)下游产品三十多个,年生产规模三万多吨,是国内以乙烯酮(双乙烯酮)为中间体生产精细化学品的综合骨干企业。针对乙烯酮(双乙烯酮)下游产品废水特点,该厂结合企业实际,开展了产品优化,结构调整,清洁生产,资源循环利用,节水降耗等工作,从源头削减了污染物的生产。同时投资二千多万元新建预处理装置三套,6000m3/d废水生化处理装置一套,使全厂乙烯酮(双乙烯酮)下游产品的废水得到了有效的治理。     

Semi-empirical equation of state of metals. Equation of state of aluminum

A semi-empirical equation of state for metals is described. Its capabilities are demonstrated by the example of the equation of state for aluminum. New experimental data are presented on the location of the isentrope of aluminum for unloading from the state at p = 229.71 GPa on the shock adiabat to an aerogel (SiO₂) of density 0.08 g/cm³. __________ Translated from Fizika Goreniya i Vzryva, Vol. 44, No. 2, pp. 61–75, March–April, 2008.     

水泥水化热测定方法综述

水泥水化热是中、低热水泥和核电工程用水泥的一项关键的技术指标。全球范围内测定水泥水化热的方法有溶解法、直接法/半绝热法、等温传导量热法三种。本文总结了中、美、欧相关方法标准,对其测试原理、仪器设备、试验过程等方面进行了比对,并对其在领域的应用做了简单的概括。     

Calorimetric and Computational Study of Enthalpy of Formation of Diperoxide of Cyclohexanone

A thermochemical rather simple experimental technique is applied to determine the enthalpy of formation of Diperoxide of ciclohexanone. The study is complemented with suitable theoretical calculations at the semiempirical and ab initio levels. A particular satisfactory agreement between both ways is found for the ab initio calculation at the 6–311G basis This set level. Some possible extensions of the present procedure are pointed out.     

我国聚碳酸酯工业发展概况

介绍我国聚碳酸酯生产能力和消费需求,对聚碳酸酯在信息工业中的应用作了简短介绍     

气化给煤系统故障分析

气化给煤装置自投运以来,出现了气化煤仓堵煤、称重给煤机输送皮带因跑偏而损伤以及清扫装置故障频繁等问题,多次造成气化系统减负荷运行。通过对出现的各种问题进行分析,找到了产生这些问题的原因,并有针对性地采用配煤和改进清扫链等措施,使出现的问题得到了极大的改善。     

Effect of degree of deacetylation of chitosan on the kinetics of ultrasonic degradation of chitosan

The objective of the study was to explore the effect of the degree of deacetylation (DD) of the chitosan used on the degradation rate and rate constant during ultrasonic degradation. Chitin was extracted from red shrimp process waste. Four different DD chitosans were prepared from chitin by alkali deacetylation. Those chitosans were degraded by ultrasonic radiation to different molecular weights. Changes of the molecular weight were determined by light scattering, and data of molecular weight changes were used to calculate the degradation rate and rate constant. The results were as follows: The molecular weight of chitosans decreased with an increasing ultrasonication time. The curves of the molecular weight versus the ultrasonication time were broken at 1‐h treatment. The degradation rate and rate constant of sonolysis decreased with an increasing ultrasonication time. This may be because the chances of being attacked by the cavitation energy increased with an increasing molecular weight species and may be because smaller molecular weight species have shorter relaxation times and, thus, can alleviate the sonication stress easier. However, the degradation rate and rate constant of sonolysis increased with an increasing DD of the chitosan used. This may be because the flexibilitier molecules of higher DD chitosans are more susceptible to the shear force of elongation flow generated by the cavitation field or due to the bond energy difference of acetamido and β‐1,4‐glucoside linkage or hydrogen bonds. Breakage of the β‐1,4‐glucoside linkage will result in lower molecular weight and an increasing reaction rate and rate constant. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3526–3531, 2003     

醋酸纤维素取代基分布与性质的关系

分析了以吡啶为溶剂的醋酸纤维素的13C-NMR核磁共振谱,得出了三种不同位置羟基的取代度。结合X—射线和DSC分析,初步说明具有相同取代度但未经水解和经过水解的醋酸纤维素(CA) 性质上的差异是由于三个羟基上的取代度分布不同及消晶程度差异所致。     

Generalization of vdW type of equations of state

1 INTRODUCTIONBecause of importance of equations of state (EOS)in science and industry,hundreds forms of EOS havebeen presented since latter 19th century.It seems impossible to develop a general equation covering vari-ous kinds of EOS.But for cubic EOS,several generalequations have been reported already. Martin presented the first general equation whichis following p=RT/V-α(T)/(υ β)(υ γ) δ(T)/υ(υ β)(υ γ) (1) Kumar et a1.presented an equation called the most general form of a density-cubic or, alterna tively,volume-cubic mathematical equation,the form of which is as follows     

几种乙炔加压设备性能的比较

阐述并比较了几种加压设备在乙炔加压清净过程中的性能和特点。