Abstract : the fraction compositions , group compositions and structure compositions of seve n catalytic stocks were determined by means of vacuum distillation , mass spectrum , element analysis and molecular mass measurement 文摘:采用减压蒸馏、质谱分析、元素分析和分子质量测定对辽河原油的7种催化原料油进行了馏分组成、族组成和结构族组成的分析。
It is installed with various production equipment for the atmospheric distillation , catalytic cracking of heavy oil , delayed cocking , hydrogenated white oil , anti - corrosion additives , alkane - purpose chemical reagent and special oils 中国石化集团杭州炼油厂现有常减压蒸馏、重油催化裂化、延迟焦化、加氢白油、防锈添加剂、烷烃化学试剂和特种油品等生产装置。
According to the frequently used methods of extraction and isolation of natural products from organic body , the freeze - dried ascidian tunica was exhaustively extracted with 100 % chloroform then the combined extracts were filtered and the solvent was separately concentrated under vacuum to yield a dark - brown gum 按照目前比较常用的天然产物的提取分离办法，将样品冷冻干燥后，用100氯仿浸泡，收集氯仿滤液，减压蒸馏浓缩去除浸提溶剂，得到黑褐色的浸膏状物质。
The recovery of atmospheric light oil yield of atmospheric in the northern atmospheric distillation tower of shenghua teaching & test factory , science and technology group of china university of petroleum has been increase by about 4 or 5 percent through the following methods : changing the tray perforation of atmospheric tower , adjusting the amount of stripping steam and the outlet temperature of the atmospheric heater and merging atmospheric excess vapor into 3rd atmospheric drawn - stream to keep the fractions content of bottom oil below 5 % before 350 摘要中国石油大学科技集团胜华教学实验厂北常减压蒸馏装置换炼胜利管输油后，通过改变常压塔塔盘开孔率、调节常压塔汽提蒸汽量和常压炉出口温度、常压过汽化油并入常三抽出线等措施，控制常压塔底油350前馏分含量小于5 % ，使常压轻质油收率提高约4 % ~ 5 % 。
The product ratio was increased to 45 % from 30 % . furthermore , lactide was recycled from the ethyl acetate recrystallization solution , and structure was investigated with ir and uv spectrum . the result indicated that the process is suitable and feasible , and the product ratio is beyond 40 % 本文在总结了目前众多聚乳酸单体? ?丙交酯的合成技术的基础上，选用减压蒸馏工艺并加以改进，设计出最佳的实验装置，使丙交酯的产率从30提高到45 ，并对重结晶后的母液进行有效的回收，回收率也能达到40 ，对回收后的丙交酯进行了测试分析，证明了回收过程的可行性。
