间歇式本体法PP装置闪蒸釜氮气连续汽提工艺研究

在间歇式本体法聚丙烯(PP)装置上研究了闪蒸釜氮气置换工艺,分析测试了闪蒸釜反复抽真空充压工艺和闪蒸釜连续汽提工艺在置换效果、氮气耗量、排人气柜氯气量、携带粉料量、置换时间等.结果表明:与反复抽真空充压工艺相比,闪蒸釜连续汽提工艺能够明显降低间歇式本体法PP装置的丙烯单耗、氮气消耗和污染物排放.     

调整操作方案降低加工损失

鉴于国内部分使用小本体聚丙烯的厂家采取负压回收技术,提高丙烯回收率。受此启发,我们讨论后认为可以采取抽真空排出氮气,用气柜内丙烯平衡闪蒸釜内压力的做法,尽量减少氮气进入气柜,达到减少氮气经尾气回收储罐排放造成丙烯损失的目的。通过试验证明,较实验前每天丙烯回收量有很大提高。目前国内同行业降低丙烯损耗的主要做法就是在闪蒸釜这里下功夫,各自都取得了理想的效果,我们目前的方案也准备长期实施。     

聚丙烯装置不凝气中丙烯回收技术方案

在液相小本体聚丙烯工业生产中，聚合后闪蒸出料时，总会有相当数量的丙烯随着闪蒸釜的减压以及置换而被放出。闪蒸所排放的气体中主要成分是丙烯和氮气，丙烯的含量约为60％～80％。传统上，这部分丙烯是被一个湿式气柜收集起来，然后用压缩机升压到2．0MPa，再经水冷却器，冷凝为液相丙烯后，回收到储罐中。由于闪蒸排放气中含有大量的氮气，因此丙烯储罐的压力会逐渐上升，在压缩时必须进行一定量的放空，以保证系统安全。     

低等规聚丙烯的研制Ⅴ.粘性聚合物的分离技术

采用液相本体法生产的粘性低等规聚丙烯在排放输送和分离回收时易堵塞阀门和管道。模试结果表明：控制聚合时丙烯转化率为20％～50％,同时预先在闪蒸釜中加人表面分散剂质量分数约0．3％的液体介质及预先充人丙烯单体可以有效地解决这一问题。介绍了采用乙醇-水溶液作为分散介质的分离技术特征,并可用深度冷冻法或吸附极性分子法从回收体系中除去乙醇。     

丙烯聚合用BCZ型催化剂的开发

在MgCl2溶解过程中加入内给电子体,开发了一种新型丙烯聚合用BCZ型催化剂,并在5 L聚合釜中进行了本体聚合考核评价,在12 m3小本体工艺装置上进行工业应用试验,在25 kg/h的连续法Innovene气相工艺装置进行中试试验。研究表明:用BCZ型催化剂制备聚丙烯(PP)时,催化剂活性高出国产同类催化剂近50%,氢调敏感性好,同样氢气用量下,PP的熔体流动速率可提高25%左右;所制PP的相对分子质量分布大于7.5,等规指数高;BCZ型催化剂可用于小本体法工艺、连续法气相工艺装置制备均聚和共聚PP。     

热塑性弹性体SBS的生产技术现状和发展趋势

总体介绍了世界热塑性弹性体SBS的供需状况 ,着重分析了聚合、闪蒸浓缩、汽提凝聚、后处理及溶剂回收等主要工艺单元的生产技术现状和特点 ,讨论了聚合釜、闪蒸浓缩釜等关键设备的大小、结构对传质、传热及产品质量的影响 ,剖析了二塔体系或三塔体系的溶剂回收精制工艺以及双釜并联或串联的汽提工艺的优缺点 ,并分析了产品后处理直接干燥法和汽提干燥法工艺的能耗 ,最后展望了SBS生产技术在品种牌号及工艺方面的发展趋势     

碳分子筛变压吸附制氮机在酮苯脱蜡装置中应用的可行性探讨

碳分子筛变压吸附制氮机广泛应用于化工、冶金、电子工业,但在炼油厂酮苯脱蜡装置中的应用还没有先例。本文提出了用碳分子筛变压吸附制氮机制取氮气满足装置过滤系统密闭及氮气汽提用气,从而取代目前惰性气发生炉通过燃烧耗氧制取氮气的常规工艺,根据项目投用后核算结果及投资回收期的预测,结论认为：碳分子筛变压吸附制氮机在炼油厂酮苯脱蜡装置中的应用是可行的。     

间歇式液相小本体聚丙烯工艺现状及优化措施

随着丙烯和聚丙烯生产工艺的多元化、大型化、一体化,间歇式小本体聚丙烯聚合装置生存空间越来越小。本文分析了小本体聚丙烯工艺和SPG(丙烯“液相本体聚合+卧式釜气相聚合”组合)聚丙烯工艺在丙烯单耗、能耗、人工成本等方面的差距,并阐述了变压吸附技术、不同催化剂、自动化控制、外循环撤热、停用溴化锂制冷等措施的应用效果,来降低小本体装置生产成本。     

膜回收技术在小本体聚丙烯装置上的应用

阐述了膜法有机蒸汽回收的基本原理,介绍了小本体聚丙烯尾气回收工艺,应用膜回收技术回收尾气中丙烯单体,同时纯化氮气,实现了节能降耗。丙烯回收率高达 95%以上,氮气纯度 95%以上。     

DSM公司将建膜法丙烯回收系统

DSM公司正在荷兰Geleen建造一套耗资100万美元的丙烯回收系统,该系统由美国加州膜技术研究公司(MTR)设计,可从聚丙烯装置排气中回收丙烯并循环用于聚合。回收的氮气将用于从聚合物产品中脱除未反应的单体。 该系统用于阿莫科/氮气(日本)公司工艺的聚丙烯装置。DSM公司设置的这套称为Va-per Sep的系统是同类设施中最大者。膜法Vapor Sep技术比其他技术(包括变压吸附)具有经     

Simulation study of biobutanol production in a polymer-loaded two-phase partitioning bioreactor (PL-TPPB): Simulation and strategy for biobutanol production

A simulation study was performed for a two-phase partitioning bioreactor (TPPB) with polymer beads, Dowex Optipore L-493, as a second phase. When the initial glucose concentration is less than 30 g/L, a single-phase bioreactor is preferred, because it consumed all the glucose with 40% of biobutanol yield. Any glucose over the concentration remained in the single-phase bioreactor because cells were completely inhibited by products, mainly biobutanol, and thus glucose availability became less than 100%. The TPPB with 10% polymer beads completely consumed up to 120 g/L glucose and more polymer beads were required for the higher glucose concentration. Instead of increasing the proportion of polymer beads, 2 vvm of nitrogen gas was introduced continuously into the TPPB for the stripping of products, reducing product inhibitions. By applying gas stripping to the TPPB containing 10% polymer beads, 150 g/L of glucose was completely consumed and 99.7% acetone, 46.8% butanol and 82.5% ethanol was stripped out of the TPPB. Finally, on the basis of these estimations, a novel strategy based on the initial glucose concentration was suggested for high biobutanol production.     

Comparison of steam and nitrogen in the physical deacidification of soybean oil

Deacidification in physical refining is one of the most sensitive steps in refining edible vegetable oils because of its large impact on the quality of the oil. The removal of volatile compounds such as FFA is accomplished at elevated temperatures and a high vacuum with a stripping gas, usually steam. The aim of this work was to verify, at the laboratory level, the advantages of using an alternative stripping gas, nitrogen, instead of steam. An ideal vapor-liquid equilibrium model (IVLE) was used to compare the stripping capacities of steam and nitrogen and to analyze the effects of various operational parameters (temperature, pressure, amount of stripping gas) on the residual acidity of the oil. There was no clear evidence that nitrogen showed a higher capacity to strip FFA than steam. The IVLE model seemed suitable to describe FFA laboratory distillation by using steam or nitrogen, provided the final residual content of FFA was not too low.     

Ethylene recovery from low grade gas stream by adsorption on zeolites and controlled desorption

Carbon dioxide was partially removed from a nitrogen stream, which also contained some ethylene, by adsorption on a 4A (Na-A) zeolite. The treated nitrogen stream was then passed over a 13X (Na-X) zeolite bed upon which ethylene and any remaining carbon dioxide were adsorbed. Ethylene was recovered by desorption at 68 Pa pressure into a slow flow of nitrogen as stripping gas. The ethylene concentration in the extracted gas was extremely dependent on the nitrogen flow-rate, whereas the concentration of carbon dioxide remained practically constant. Thus, it was possible to obtain a gas mixture greatly enriched in ethylene with a reasonably low content of carbon dioxide.     

低温甲醇洗用净化气作汽提气的原始开车方法

介绍低温甲醇洗装置在没有氮气置换和汽提气的条件下,采用造气制惰气置换和净化气作汽提气的原始开车方法。     

聚丙烯装置尾气回收利用技术

在聚丙烯的生产过程中,尾气中含有较多的丙烯,本文尝试利用催化精馏技术解决尾气中丙烯的吸收问题,将苯与丙烯在催化剂上反应生成异丙苯,初步研究表明,使用氮气与丙烯体积比为1：1的混合气时,可使丙烯转化率大于90％,所得产品中异丙苯的选择性大于96％,丙烯的质量空速可达1．5－2．5h^-1,证明催化精馏技术是北方是此方面很有前途的工程技术之一。     

Comparative performance of steam and nitrogen as stripping gas in physical refining of edible oils

Olive, sunflower, and soybean oils were physically refined in a discontinuous laboratory system with either nitrogen or steam as stripping gas during the deodorization step. Comparative assays were also carried out on olive oil in a 10-MT discontinuous industrial plant. Vaporization efficiency of free fatty acids was calculated, and quality of refined oils and composition of deodorizer distillates were analyzed. Results indicated that, in all assays, the efficiency of free fatty acid distillation was higher when nitrogen was used. The amount of nitrogen needed was much lower than that of steam for refined oils of similar high quality. The results also suggested that the amount of stripping gas had a clear influence on the composition of deodorizer distillates because lower quantities of triglycerides and unsaponifiable matter were found when nitrogen was employed.     

Relationships among the variables involved in the physical refining of olive oil using nitrogen as stripping gas

The use of nitrogen as stripping gas has been proposed as an interesting alternative to steam in physical refining and deodorization. A 2³ experiment has been carried out with olive oil in a 200 kg discontinuous deodorizer in order to study the relationships among the independent variables involved in the physical refining process - nitrogen flow, temperature and oil load. The results have shown that at about 245°C and with a nitrogen stripping gas flow of 1500 l/kg.h it is possible to get refined oil with less than 0,4% of free fatty acids and quality indices adjusted to the ECC standards. Using these conditions the acidity is practically independent of the oil load within the limits of the experiment (125–175 kg of oil load).     

凝液汽提塔在乙烯装置前脱乙烷流程中的应用探讨

在百万吨级前脱乙烷流程的乙烯装置裂解气压缩机工艺系统中进行了凝液汽提工艺的研究。模拟计算了凝液汽提塔在裂解气压缩机第四与五段之间时裂解气压缩、分离和制冷系统的变化情况,考察了该塔塔压的变化对这些系统的影响。研究结果表明,应用凝液汽提塔可降低脱乙烷塔塔底温度13℃以上,减少低压蒸汽消耗量,不会增加乙烯制冷压缩机的功率,但增加裂解气压缩机和丙烯制冷压缩机的功率,使综合能耗有所上升;凝液汽提塔塔压对低压蒸汽消耗量的影响较大,而对裂解气压缩机、丙烯和乙烯制冷压缩机的功率影响较小,当塔压为0．9MPa时,综合能耗最低。当凝液汽提塔被设置在裂解气压缩机第四与五段之间时,不建议在新建前脱乙烷流程的乙烯装置中应用它。     

氢气气柜运行保障措施

在离子膜电解法产碱工艺中,氢气气柜一方面在系统正常运行时维持氢气压缩机进口压力稳定,另一方面在系统出现异常状况时能够给操作人员一定的缓冲时间进行应急操作.介绍保障氢气气柜稳定运行的措施:①完善气柜检修标准;②完善气柜联锁逻辑控制;③完善气柜自动切断系统;④完善气柜水封槽水温检测和液位检测;⑤完善氢气泄漏预警;⑥完善气柜...