宝鸡氮肥厂斯那姆汽提尿素装置的设备国产化

宝鸡氮肥厂采用意大利斯那姆氨汽提工艺将氨加工产品碳铵改产尿素，其设计能力搂４００ｔ／ｄ。文中介绍了该厂尿素装置的特点，试车情况及试车期间出现的设备问题，并提出了在今后尿素工程设计中应注意的问题。     

宝鸡氮肥厂斯那姆氨汽提尿素装置的设备国产化

宝鸡氮肥厂采用意大利斯那姆氨汽提工艺将氨加工产品碳佞改产尿素，其设计能力为400t／d。文中介绍了该厂尿素装置的特点、试车情况及试车期间出现的设备问题，并提出了在今后尿素工程设计中应注意的问题。     

CO2汽提法尿素装置的改造总结

0前言安徽吴源化工集团有限公司（以下简称吴源公司）尿素装置采用Stamicarbon公司的CO2汽提工艺。自装置投产以来,CO2汽提工艺操作弹性大、运行稳定等优点都得到了充分体现,但尚存在不足之处,导致尿素的氨耗、蒸汽耗、CO2转化率未能达到最佳指标,进一步改进的空间仍很大。近年来,吴源公司通过优化工艺、技术改造取得了良好的节能效果。     

CO2汽提尿素装置增产改造技术的成功应用

介绍了山东华鲁恒升化工股份有限公司应用北京众联盛化工工程有限公司开发的“一种二氧化碳尿素装置节能增产新技术”对1 #尿素装置的改造情况.在原高压系统和低压系统之间,通过增加中压分解吸收系统,改二段蒸发为三段蒸发,增加预蒸发真空浓缩系统,并对部分高压设备的内件进行了改造,达到CO2汽提尿素装置产能增加50％的目的,取得显著的增产、节能降耗效果.     

氨汽提尿素装置泵类设备国产化浅析

叙述氨汽提尿素生产装置泵类设备在选型、安装、试车、生产过程中的一些改造情况,通过技术改造或重新选型、使之达到长周期、高负荷运行。说明氨汽提尿素装置泵类设备国产化是完全可以成功的。     

CO2汽提法尿素装置低压开车总结

介绍了CO2汽提法尿素装置低压开车的特点与优点,分析了低压开车法的可靠性,总结了低压开车法的操作要点,提出了推广普及低压开车法的建议.     

CO2汽提法尿素工艺中的节能方法

尿素生产过程中,尿素混合液通过蒸汽加热的方式完成分解,高温气体需要冷却水冷却,最大程度对物料进行回收,从而缩短消耗的目标.大部分热能被循环水带走后,冷却水温度增高,导致冷却设备功能无法体现.主要对传统二氧化碳汽提法发展角度进行分析,探究CO2汽提法蒸汽消耗的因素,提出CO2汽提法尿素工艺中节能方法.     

氨汽提尿素装置扩能改造的可行性分析

介绍中石油宁夏石化分公司二化肥尿素装置的现状，拟采用二氧化碳汽提法对装置进行50％扩能改造，分析改造方案的可行性。     

Effects of the catalyst pretreatment on CO2 sensors made by carbon nanotubes

A novel CO₂ sensor was made by carbon nanotubes (CNTs). The CNTs were synthesized by catalystic thermal chemical vapour deposition at 700 °C. Prior to the synthesis, the Fe catalysts were pretreated by H₂ plasma for different times. Two terminal resistance of the as-grown CNTs mat was measured under different CO₂ concentrations. It was found that without the catalyst pretreatment, the sensitivity was about 4% when the CNTs mat was exposed to 800 mTorr CO₂ concentration. However, with various catalyst pretreatment times of 5, 10, 15 and 20 min, the sensitivity was 3.69%, 6.27%, 9.54%, and 12.1%, respectively. The Raman spectroscopy showed the I_D/I_G decreased from 0.668 to 0.539 as the catalyst pretreatment time increased. The XPS also showed the correlation of surface chemical components with the Raman spectroscopy. The Fe catalyst H₂ plasma pretreatment affected both the graphitization and surface binding sites of CNTs.     

Thermal degradation of diethanolamine at stripper condition for CO2 capture: Product types and reaction mechanisms

Amine-based absorption/stripping is one of the promising technology for CO₂ capture from natural and industrial gas streams. During the process, amines and CO₂ undergo irreversible reactions to produce undesired compounds, which cause corrosion, foaming, increased viscosity and breakdown of equipment, ultimately contributing to the economic loss and environmental pollution. In this study, the thermal degradation of aqueous diethanolamine in the presence and absence of dissolved CO₂ was investigated. The experiments were performed in stainless steel cylinders. The results show that thermal degradation in the absence of CO₂ was a slow process; triethanolamine, and tris(2-aminoethyl)amine were only the degradation products identified in the mixture In addition, the rate of degradation was very low, only 3% degradation was observed after 4 weeks. But in the presence of CO₂, sixteen degradation products were identified, nine of which were new degradation products reported for the first time in this study. The 3-(2-hydroxyethyl)-2-oxazolidinone, 1,4-bis(2-hydroxyethyl)piperazine and triethanolamine were the most abundant degradation products. The remaining DEA concentration after 4 weeks was about 20% of the total amine concentration. The most probable degradation reactions and their mechanisms are also proposed.     

Physical properties of aliphatic polycarbonates made from CO2 and epoxides

A homologous series of aliphatic polycarbonates with different side‐chain lengths was synthesized by ring‐opening polymerization of terminal epoxides with CO₂ using zinc adipionate as catalyst [patented process of Empower Materials (formerly PAC Polymers Inc.)]. Additionally, a polycarbonate was made having a cyclohexane unit in its backbone, together with a terpolymer having both cyclohexane and propylene units. After characterization of thermal properties the aliphatic polycarbonates were found to be completely amorphous. Polycarbonates derived from long‐chain epoxides showed a glass‐transition temperature (T_g) below room temperature, whereas polycarbonates derived from cyclohexene oxide showed a T_g of 105°C, the highest yet reported for this class of polymers. The initial decomposition temperature of the polymers in air and nitrogen atmospheres was found to be less than 300°C. The mechanical properties and the dynamic mechanical relaxation behavior of the polymers were also reported. The effect of the chemical structure on the physical properties of aliphatic polycarbonates was discussed. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1163–1176, 2003     

汽提塔修理的经验总结

1我公司汽提塔概况我公司尿素装置采用的是意大利斯那姆公司的氨汽提工艺。装置中的汽提塔是从意大利FBM-HUDSON公司进口的,1992年3月随着整套装置的建成投产而投运。汽提塔设计参数如下：壳程管程设计压力2．6 MPa16．5 MPa试验压力3．6 MPa20．63 MPa设计温度230 ℃230 ℃介质蒸汽尿液充满水后全重30．65 t设备本体金属重24．9 t管板连接方式焊 胀列管．φ27×3．5,545根管长4964 mm管间距34．5 mm材质SB338GR3(纯钛管)总传热面积154 m．2考虑到列管头工作条件苛刻,设备整体设计成对称型,使用厂可在适当时候掉头。2重要故障…     

A study of foaming problems in a CO2 removal system

Carbon dioxide (CO₂) is removed by absorption in hot potassium carbonate (HPC) solution in ammonia plant. Under actual field conditions, HPC solution can be easily contaminated by system impurities in the circulating solution. These impurities enhance foaming in the CO₂ removal system, which has significant effects in reducing equipment capacity and increasing processing time. In this study, it is assumed that the main cause of foaming is the presence of potassium soap in the HPC solution. The effects on foaming problems of adding calcium oxide have been investigated. The role of a charcoal bed and filtration have also been examined. The results showed that a significant reduction in foam height in an actual field solution can be obtained by using calcium oxide. Values of up to 97% reduction in foam height have been achieved.     

CO2压缩机系统运行常见问题探讨及应对措施

通过对现国内CO2压缩机运行中常见的一些问题，如揣振、高低压缸振动、级间冷却器管束的损坏等进行分析和探讨，提出应对措施，并应用于江苏灵谷52万t／a产尿素装置CO2压缩机的设计上，使投入使用的压缩机能持续稳定地运行。     

联碱CO_2冷却工艺流程简介

对联碱原有CO2气冷却工艺流程和改造后的工艺流程进行了简要的介绍和对比,并对新工艺运行过程中出现的问题进行了分析和总结,进而提出了整改意见。     

汽提塔稳定运行的工艺措施

分析探讨了汽提塔使用过程中出现的问题及采取的处理方法。找出了影响设备正常运行的不利因素。介绍了采取的有效措施。经改进，延长了汽提塔的稳定运行时间。