合成气压缩机干气密封异常的原因分析及对策

介绍合成气压缩机高压缸串联式干气密封的结构、一级密封气系统、二级密封气系统、隔离气系统及放空气控制系统,结合操作流程,对高压缸非联轴器侧一级泄漏气出现的异常现象进行分析,得出在推力瓦检修、转子轴左移作用下,颗粒、粉末及少量润滑油造成了二级静环支撑座被卡,静环与动环分离,形成二级密封泄漏通道.同时对于气密封运行进行安全风险评价,通过更换干气密封消除隐患,为避免类似故障再次发生,提出相应的对策.     

无动力氨回收装置的运行总结

无动力氨回收装置是回收合成氨弛放气中气态氨的一项节能环保新技术装置。介绍了河北金源化工股份有限公司无动力氨回收技术的原理、工艺流程、主要设备特点、工艺指标及运行情况。该厂无动力氨回收装置各项温度压力指标均在设计范围内,氨回收率达到98%,尾气氨含量〈1.1%,年回收氨约为3 500 t,年增效益350万元。     

壳牌煤气化装置洗涤塔出口合成气带水原因分析及对策

介绍了壳牌粉煤气化装置中洗涤塔工艺流程;分析了洗涤塔内部结构;阐述了洗涤塔出口合成气带水的现象及危害;找出了引起洗涤塔工艺气带水的原因;采取了相应的技改措施。结果表明,通过调整工况,消除了带液现象。     

焦炉煤气生产合成氨、尿素项目关键问题分析

为合理利用焦炉煤气,实现焦炉煤气生产合成氨、尿素项目实现安稳长满优运行,通过分析项目中焦炉煤气气量及组分(特别是硫含量及杂质),选择压缩机、转化炉等主要设备,分析合成氨、尿素负荷的匹配,施工队伍等关键问题对项目建设和生产的影响。提出了焦炉煤气气量及组分确定方法,压缩机、转化炉选型要求,合成氨、尿素负荷匹配设计以及施工单位选择原则。应充分估算焦炉气量,搞清焦炉气成分,以便确定合理生产规模和主要工艺,特别要考虑焦炉气中杂质对工艺系统的影响。应选择性能可靠稳定的往复式焦炉气压缩机、净化气压缩机、循环气压缩机和CO2压缩机,保证生产安全稳定连续运行。     

高黏度聚α-烯烃合成油加氢技术研究

采用中国石油石油化工研究院开发的Pt-Pd/Al_2O_3加氢精制催化剂对聚α-烯烃PAO40粗产品进行了加氢精制。结果表明:在反应温度240~280℃、反应压力4.0~8.0 MPa、体积空速0.1~0.4h-1、氢油体积比300∶1的工艺条件下,PAO40加氢产品的芳烃含量达到国外同类优秀产品水平;PAO40加氢产品经光照30天后不变色,具有较好的光安定性。     

低温法费-托合成油加氢提质CFH~L技术开发及工业应用

介绍了中国石化石油化工科学研究院开发的低温法费-托合成油加氢提质CFH~L技术及工业应用情况,考察了操作条件对异构加氢裂化反应效果的影响。结果表明,反应温度、氢分压、体积空速对异构加氢裂化反应效果影响显著,氢油体积比影响较小。CFH~L技术工业应用结果表明,稳定加氢柴油馏分十六烷值为81,凝点小于-20℃;异构加氢裂化柴油馏分选择性为82.2%,异构裂化柴油馏分十六烷值为76,凝点为-53℃。     

Stereoselective Synthesis of Pyrroloquinolines by a Brønsted Acid Catalyzed [4+2]‐Heterocyclization of Indole‐7‐Carbaldehydes,Anilines and Electron‐Rich Alkenes

The pyrrolo[3,2,1‐ij]quinoline heterocyclic core is found in the structure of a variety of compounds with interesting applications and then, new efficient and flexible strategies to construct this skeleton are required. Here, a new diastereoselective tetrafluoroboric acid (HBF₄)‐catalyzed three‐component coupling reaction of 1H‐indole‐7‐carbaldehyde derivatives, anilines and electron‐rich alkenes to give pyrrolo[3,2,1‐ij]quinolines is described. The reaction involves an unusual [4+2]‐heterocyclization between an in situ formed imine and an alkene. The new catalytic method, where water is the only by‐product, is efficient, robust and flexible, and allows for multigram‐scale synthesis.

     

Iron‐Catalyzed Azidoalkylthiation of Alkenes with Trimethylsilyl Azide and 1‐(Alkylthio)pyrrolidine‐2,5‐diones

A simple, efficient and practical iron‐catalyzed azidoarylthiation of alkenes has been developed at room temperature, and the corresponding products containing ortho‐sited sulfide and azide units were obtained in moderate to good yields with good tolerance of functional groups. The protocol uses readily available 1‐(alkylthio)pyrrolidine‐2,5‐diones and trimethylsilyl azide as the alkylthiation and azidation reagents, respectively, inexpensive and environmentally friendly iron chloride as the catalyst without addition of any ligand and additive.

     

The Reactivity of Difluorocarbene with Hydroxylamines: Synthesis of Carbamoyl Fluorides

Carbamoyl fluorides are formed in reactions of hydroxylamines with difluorocarbene generated from sodium bromodifluoroacetate as readily available and non‐toxic carbene precursor. The process shows a high functional group tolerance, and the reaction path has been rationalized by computational calculations.

     

Disulfides as Sulfonylating Precursors for the Synthesis of Sulfone‐Containing Oxindoles

The first facile one‐pot synthesis of sulfone‐containing oxindoles with easily accessible disulfides as the sulfonylating precursors is described. This reaction occurs smoothly under transition metal‐free conditions and shows excellent functional group tolerance, allowing the facile and efficient green synthesis of various sulfone‐containing oxindoles in aqueous solution. Preliminary mechanistic studies reveal that both water (H₂O) and potassium persulfate (K₂S₂O₈) can be the oxygen source of the sulfone groups in the products.