Phase equilibria of clathrate hydrates of methyl cyclopentane, methyl cyclohexane, cyclopentane or cyclohexane+carbon dioxide

In this work, experimental dissociation data for clathrate hydrates of methyl cyclopentane, methyl cyclohexane, cyclopentane or cyclohexane+carbon dioxide are reported at different temperatures. The experimental data were generated using an isochoric pressure-search method. The reliability of this method is examined by generating new dissociation data for clathrate hydrates of methyl cyclopentane+methane and comparing them with the experimental data reported in the literature. The acceptable agreement demonstrates the reliability of the experimental method used in this work. The experimental data for all measured systems are finally compared with the corresponding literature data in the absence of the above mentioned cyclic compounds to identify their promotion effects.     

Tribological behavior of a multialkylated cyclopentane oil under ultrahigh vacuum conditions

An ultrahigh vacuum, ball-on-flat test apparatus has been built to study the performance of candidate oils intended for spacecraft applications. Tests have been conducted on a multialkylated cyclopentane base oil using steel balls and disks. Different results are obtained when this oil is tested under vacuum conditions than when it is tested under a nitrogen environment. These differences are dramatic when the tests are conducted under starved conditions. Analyses of gases evolved during rubbing reveal that large quantities of methane are evolving from the process. A mechanism is proposed whereby oxide-free steel surfaces combine with tribological activity to crack the hydrocarbon oil to produce CH _x radicals. These CH _x radicals abstract hydrogen from the surrounding oil to produce methane. The increased volatility of the oil fragments remaining after methane formation leads to material loss by evaporation, thereby explaining the differences in vacuum and nitrogen performance of the oil.     

N -甲酰吗啉在脱硫工艺中的应用

N-甲酰吗啉(NFM)由于其物理性质及化学结构的特点,除用于萃取精馏回收和精制芳烃外,还有较好的脱硫效果,并且有很好应用前景.     

365mfc/245fa/环戊烷三元混合体系发泡技术在冰箱的试验研究

HFC-245fa、HFC-365mfc、HFC-LBA等新型发泡剂的出现,为聚氨酯发泡技术发展带来了新突破。本文介绍了一种基于365mfc/245fa/环戊烷三元混合体系的新型发泡技术,并开展了其在冰箱上的应用研究。     

降低汽油馏分中苯含量的烷烃异构化技术

在小型评价装置上,考察了苯、甲基环戊烷、环己烷组分在工业中温异构化催化剂上的转化规律。结果表明：在中温异构化反应条件下,异构化原料中的苯经加氢全部转化,反应温度低于220 ℃时,苯完全转化为甲基环戊烷和环己烷,裂解活性较低;随着温度的升高,开环产物增加,裂解反应加剧。甲基环戊烷的转化率随温度升高而增加,低温下的产物主要为环己烷,随着温度的升高,裂解反应加剧,裂解产物明显增加。环己烷的转化率随温度升高而增加,低温下的产物主要为甲基环戊烷,随着温度的升高,裂解反应加剧,裂解产物增加。对于甲基环戊烷、苯、环己烷总含量较低的异构化原料,可以选择现有的异构化流程,实现苯全部转化,而对产物的辛烷值和液体收率影响不大。对于甲基环戊烷、苯、环己烷总含量较高的异构化原料可以选择（精馏+异构化）组合工艺,通过工艺条件的控制,可以使异构化产物中具有较高的甲基环戊烷和环己烷含量,产品的辛烷值提高。     

正己烷-甲基环戊烷-N-甲基吡咯烷酮三组分物系汽液平衡的测定及萃取精馏的模拟

采用改进的Othmer汽相单循环平衡釜,在常压下测定了正己烷-甲基环戊烷-N-甲基吡咯烷酮(NMP)三组分物系的汽液平衡数据。采用NRTL方程对实验数据进行关联,回归得到了NRTL方程的模型参数,汽相摩尔分数的实验值和计算值平均绝对相用对偏差为1.96%。萃取精馏正己烷-甲基环戊烷适宜的萃取剂与原料的质量比(溶剂比)为8。模拟结果表明,采用NMP为萃取剂、萃取精馏正已烷-甲基环戊烷适宜的条件为:溶剂比8、理论板数45、原料进料位置第26块塔板、萃取剂进料位置第7块塔板、回流比为2。在此条件下,塔顶馏分中正己烷的质量分数可达99.10%。     

Reference Correlation for the Viscosity of Liquid Cyclopentane from 220 to 310 K at Pressures to 25 MPa

A correlation in terms of temperature and molar volume is recommended for the viscosity of liquid cyclopentane as a reference for low-temperature, high-pressure viscosity measurements. The temperature range covered is from 220 to 310 K and the pressure range from atmospheric up to 25 MPa. The standard deviation of the proposed correlation, within a 95% confidence limit, is 1%.     

Experimental measurement and thermodynamic modeling of cyclopentane hydrates with NaCl,KCl, CaCl2, or NaCl‐KCl present

Consistent phase equilibrium data for cyclopentane hydrates in presence of salts are vitally important to many industries, with particular interest to the field of hydrate‐based water separation via cyclopentane hydrate crystallization such as desalination. However, there are very little experimental equilibrium data, and no thermodynamic prediction tools. Hence, we set up a method to generate a great deal of much needed equilibrium data for cyclopentane hydrates in diverse saline solutions with a wide range of salt concentrations. Our method does furnish verified, reliable and accurate equilibrium data. Plus, three thermodynamic approaches are developed to predict equilibrium, and provide tools for simulations, by considering the kind of salt and concentrations. All three models are in very good accordance with experimental data. One method, using a new correlation between occupancy factor and water activity, might be the best way to obtain consistent, quick, and accurate dissociation temperatures of cyclopentane hydrate in brine. © 2018 American Institute of Chemical Engineers AIChE J, 64: 2207–2218, 2018     

冰箱用环戊烷发泡体系组合聚醚的研制

通过对泡沫稳定剂和国产聚醚的筛选 ,研制的HY5 10 6环戊烷组合聚醚具有不分层、流动性优良及泡孔细腻等特点。它用于冰箱的保温层 ,其泡沫的主要性能指标为 :平均芯密度35 .6kg/m3,最大芯密度差 1.6kg/m3,10 %压缩强度 170kPa ,导热系数 0 .0 191W/ (m·K) ,低温尺寸稳定性 0 .2 1%。结果表明 ,HY5 10 6环戊烷组合聚醚完全能满足家电等产品的生产要求     

环戊烷高压发泡聚氨酯模塑生产成套设备

介绍了采用环戊烷发泡剂替代CFC—11的聚氯酯泡沫发泡工艺路线，陈述了相应的环戊烷发泡成套设备的用途及主要构成。