Effect of Sulfur on the Performance of Three-Way Catalysts

Sulfur content is one of the fuel properties to be monitored. Sulfur dioxide, the major product derived from organic sulfur compounds in the exhaust gas emissions, is a poison to the three-way catalysts (TWC). A gas mixture was applied to simulate the exhaust gases used in the TWC aging procedure tests. Two types of the TWC, REX-ⅡC and REX-ⅡD, were tested in this study. The performance of both TWC‘s before and after the 100-hour sulfur aging program was compared. It was concluded that the Pt component in the TWC was apt to bepoisoned by sulfur much easily than Rh. The performance of the REX-ⅡD catalyst was generally better than thatof the REX-ⅡC catalyst.     

Study on Reduction of Sulfur Content in FCC Gasoline

Reduction of sulfur content in FCC gasoline was studied in a fixed fluid bed (FFB) unit by using metal-modified LV-23 FCC catalyst. The results showed that the sulfur content in FCC gasoline could be reduced with LV-23 catalyst modified with zinc, palladium, zinc-palladium, zinc-cobalt, and zinc-nickel. Among these metals or metal combinations, palladium-containing catalyst was the most effective. Desulfufization of the heavy fraction of FCC gasoline was more effective than full-range gasoline under the same conditions with palladium-containing catalysts. A high reaction temperature was favorable to desulfurization, but it would reduce the yield of liquid product. After desulfurization reaction, the olefm content of product gasoline decreased while the aromatic and iso-alkane contents increased. Removal of thiophene and benzothiophene is higher.     

Commercial Application of the MIP Technology in RFCC Unit

PetroChina Jinxi Petrochemical Branch Company has applied the MIP technology in its RFCC unit to maximize the light distillate while using the paraffinic gas oil blended with resid and the coker gasoil as the feedstocks. The outcome of the unit operating according to the MIP mode has revealed that the olefin content in the stabilized gasoline could be reduced to less than 35 % with its research octane number equivalent to and its motor octane number slightly higher than the octane rating of the FCC naphtha obtained by the former operational mode of the RFCC unit, and the diesel yield could reach over 30 m%. The total liquid yield （LPG＋gasoline＋diesel） of the unit operating according to the MIP mode was by over 1.5 percentage points higher than that achieved in the former RFCC unit.     

SSHT Process-a Low Cost Solution for Low Sulfur and Low Aromatics Diesel

The need for cleaner fuels has resulted in a continuing worldwide trend to reduce diesel sulfur and aromatics. There are many approaches to reducing sulfur and aromatics in diesel. Most of them have a common drawback of high cost because of adopting two stages of hydrotreating and using noble-metal catalyst, especially for reducing aromatics. The attempt to resolve this issue has led to the recent development of the Single Stage Hydrotreating (SSHT) process by Research Institute of Petroleum Processing (RIPP), SINOPEC.The SSHT process is a single-stage hydrotreating technology for producing low sulfur and low aromatics diesel. The process uses one or two non-noble-metal catalysts system and operates at moderate pressure. When revamping an existing unit to meet low aromatics diesel specification, the only thing to do is to add a reactor or replace the existing reactor. In pilot plant tests, the SSHT technology has successfully treated SRGO (Straight Run Gas Oil), LCO (Light Cycle Oil) or the blend of them. It is shown that by using the SSHT process diesel with sulfur of 30 ppm and aromatics of 15 m% can be produced from Middle-East SRGO and diesel with aromatics content of 25 m% can be produced from cracked feed, such as FCC-LCO. High diesel yield and cetane number gain (from cracked feed stocks) give the SSHT technology a performance advantage compared to conventional hydrocracking and hydrotreating processes.The lower investment and operating cost is another advantage. The first commercial application of the SSHT technology has been in operation since September 2001.     

A Survey of Novel Processes to Produce Ultra Low Sulfur Gasoline

The restriction on sulfur level in gasoline has been increasingly tightened. The U.S.Tier Ⅱ regulation requires a reduction from average 340ppm to 30ppm from 2004 to 2008. Recently significant progress has been made in effective high sulfur removal, such as post treatment of FCC gasoline by selective hydrotreating, S Zorb sulfur removal technology, OATS process etc. The sulfur content of FCC gasoline can be deceased to less than 10ppm. With regard to gasoline pool composition in China, it is very important to look for effective desulfurization processes that are simple, straightforward, with less hydrogen consumption. Post-treatment of FCC gasoline is a preferred option. From the point of view of comprehensive utilization, alkylation, polymerization, isomerisation etc. can be added to desulfurization process to meet the requirement of ultra low sulfur, premium.     

MIP技术的灵活性

本文主要介绍MIP 技术适应市场需求所取得的技术灵活性进展,并就其工业应用情况以及技术原理进行了分析。MIP技术原料适应性强,与各种汽油脱硫技术协作性良好。基于MIP平台,开发了CGP, MIP-LTG与MIP-DCR等系列MIP技术,增强了技术灵活性,应用广泛。MIP技术因其独特的双反应区新型反应控制技术,通过调整催化剂与操作参数,使得MIP生产装置在多产异构烷烃的清洁汽油（MIP）和生产清洁汽油并增产丙烯（CGP）以及多产柴油3种生产模式之间根据需要自由切换,灵活选择生产模式,合理调整生产方案; MIP-DCR 技术通过优化催化剂与反应进料的接触温度,降低了干气和焦炭产率,并使得剂油比成为独立操作参数,为MIP技术进一步提高了操作灵活性。     

Study on Modeling for a New FCC Technique——MIP Riser Reactor

This research work developed a model for the MIP riser reactor using the data collected from an industrial MIP unit.Based on analysis of flow patterns in the reactor,three models were established and a comparison was made on each other.The results indicated that Model Ⅲ,which was assumed a plug flow in the first reaction zone and a gas plug flow and a continuously stirred catalyst flow in the second reaction zone,was the best.The results of this research could offer an information and guidance for optimization and development of MIP unit.     

Commercial Application of the RAR Sulfur Recovery and Tail Gas Treating Process

The 40kt/a sulfur recovery unit for tail gas treating applying the reduction-absorption-recycling (RAR) technology is aimed at regeneration of the rich amine solution and recovery of sulfur to operate in tandem with the 1.2Mt/a diesel hydrofining unit. The process unit calibration data have revealed that the recovery of total sulfur reaches 99.86%, which is 6.65 percentage points higher than that before application of the RAR technology. The SO2 content in vented tail gas is 0.27 t/d, which is much less than the latest emission standard prescribed by the State. The factors that can affect the unit operation have been analyzed and corresponding measures have been suggested including the necessity to improve the control over the reaction temperature in the tail gas hydrogenation unit.     

MIP工艺工程技术的进展

多产异构烷烃的催化裂化(MIP)工艺在国Ⅲ和国Ⅳ标准汽油质量升级的过程中发挥了重要作用,并形成了一系列的MIP技术.MIP工艺通过提升管设置串联的第二反应区(二反)建立反应床层和补充待生催化剂降低二反空速,采用缓和的反应条件强化异构化反应,可以将催化汽油烯烃体积分数降至35％以下,苯质量分数降至1.0％以下.多产清洁汽油和丙烯(MIP-CGP)工艺可以将汽油中烯烃的体积分数降低至18％以下,同时将汽油中的芳烃体积分数提高至18％以上,汽油辛烷值(RON)提高1个单位,相对原料的丙烯产率提高到8％～10％.降低焦炭和干气(MIP-DCR)工艺在一反底部增设催化剂预提升混合器,可大幅度降低原料油与再生催化剂的接触温差,进一步降低干气和焦炭产率,增加总液体收率0.15百分点以上.增产高辛烷值汽油(MIP-LTG)工艺将约占柴油30％的柴油轻组分返回提升管再裂化,使液化石油气+汽油产率增加1百分点以上,汽油辛烷值(MON)增加0.5个单位.     

Determination of Sulfur Content at PPB Level in Light Ois by Oxidative Microcoulometry

A method for determinaiton of sulfur content at ppb leve in light oils is proposed .The key technique of the method inluces the design of a new of pyrolysis tube,which is charactierized by large capctiy and nested struchture ,and the optimization of operation conditions.The achiveable lowest detection limit is 50ng/g.For the samples in which the sulfur content is less than 1 mg/L,This method features better precision and accuracy,good linearity and quicker test speed.     

MIP技术工业应用及其发展

介绍了MIP技术及其特点,举例分析MIP技术主要方案的工业应用情况。由于显著的经济和社会效益,到目前为止MIP技术工业应用达到30套,总加工能力接近50 Mt/a,约占全国催化裂化装置加工量的50%。MIP技术标定统计平均数据显示,应用MIP技术后总液体收率平均增加了1.56个百分点;汽油烯烃明显降低,平均降低了14.26个体积百分点;而汽油研究法辛烷值平均增加了0.4个单位,马达法辛烷值平均增加了1.2个单位;汽油硫传递系数平均降低27.95%。MIP技术作为开放性的技术平台,逐步发展了降低干气与焦炭产率,及多产高辛烷值汽油的新技术。     

延长炼化MIP装置运行分析

介绍陕西延长石油(集团)有限责任公司4套MIP装置运行情况,根据各装置生产统计数据,对其干气和焦炭产率进行了核算,分析其物料平衡和产品性质,并提出了操作调整建议。     

催化裂化MIP—CGP技术通过鉴定

据“中国石化报，2005—05—13”报道，由中国石化九江石化公司开发的“催化裂化工艺（MIP—CGP）工业试验”项目，经试运行，于2005年4月底在九江石化通过专家鉴定。     

Dazhou Becomes China’s Sulfur Base

Located at the juncture of Sichuan, Hubei, Shaanxi provinces and Chongqing municipality, Dazhou, which is a city in the eastern part of Southwest China＇s Sichuan Province and has convenient transport facilities, boasts natural gas reserves of 3.8 trillion cubic meters, of which 660 billion cubic meters have been found. It will make full use of its natural gas reserves to build Asia＇s largest sulfur producing base by 2010 when its annual sulfur output is expected to surpass 4 million tons.     

安庆石化催化裂化装置采用MIP技术

中国石化安庆石化分公司利用催化裂化两器更新之际,采用石油化工科学研究院开发MIP多产异构烷烃技术对原有重油催化裂化装置进行改造。两器采用同轴结构,再生器采用湍流床单段逆流再生工艺,装置规模仍为1.2Mt/a,设计掺炼30%减压渣油,15%焦化蜡油。据悉,该催化裂化装置已于今年年初一次喷油开车成功,工程总投资1.2亿元。经过攻关组人员的共同努力,装置生产平稳,运行状况良好,基本达到MIP改造的预期效果。催化裂化汽油烯烃含量从原来的大于52%下降至现在的35%左右,硫含量从原来的1200mg/g下降至现在的800mg/g左右,辛烷值PON从90上升到92,…     

催化裂化装置MIP反应器检修关键问题分析

2008年是天津分公司催化裂化装置反应器MIP改造后的第一次大修,检修中发现设备内衬里及设备内构件都有不同程度的损坏,文章对MIP反应器衬里及关键内构件损坏的原因和维修方案进行了分析,可为今后设备大检修提供借鉴。     

催化裂化MIP工艺原料油聚类研究

以催化裂化MIP装置工业数据为基础,选取原料油性质中的密度、饱和烃含量、芳烃含量、（沥青质+胶质）含量、镍含量、钒含量、残炭7个变量,分别采用K-means和FCM算法对原料油性质进行聚类。K-means聚类法将原料油性质的95组样本分为4类,FCM聚类法将原料油性质的95组样本分为5类。聚类结果中的每一类原料油特征都比较明显,表明K-means和FCM聚类法对于原料油性质的聚类分析均具有较好的适用性。以此为基础,可以针对每一类原料油建立相应的产品分布优化智能模型,为寻找目的产品收率最大化的操作条件提供指导。