新型克劳斯硫回收尾气处理工艺探析

简介克劳斯硫回收工艺的发展历程,对国内外各种硫回收工艺的技术经济性进行比较,指出未设尾气处理系统的克劳斯硫回收装置总硫回收率只有96%左右,而增设尾气处理系统后克劳斯硫回收装置总硫回收率可达99%以上,符合排放标准要求,但投资会大幅增加。常规硫回收装置工艺气脱硫与动力锅炉烟气脱硫是2套独立的装置,将二者有机地结合起来可形成新型克劳斯硫回收尾气处理工艺(无需增设尾气处理系统),从而达到减少投资、节能环保的目的。     

克劳斯硫回收装置现有尾气处理的技术升级

介绍了克劳斯硫回收装置尾气处理方法中超优克劳斯和还原加氢工艺的技术特点,探讨了适合煤化工硫回收尾气深度处理的技术,得出碱洗工艺优于其他技术的结论;从环保、投资成本、操作费用三方面,比较了超优克劳斯、超优克劳斯+碱洗、还原加氢、还原加氢+碱洗工艺的优缺点,为新建硫回收装置及改造项目提供了参考依据。     

富氧硫回收工艺新进展

结合国内硫回收装置扩能的实际情况,跟踪国外富氧硫回收技术的发展,针对不同工况的需求、硫处理能力、原有装置界区与设备条件、现场及投资的不同,提供了几种可供选择的优化方案,达到装置扩能与提高硫回收率的目的.     

超优克劳斯硫回收工艺技术及应用前景

超优克劳斯硫回收工艺是在传统克劳斯工艺基础上开发的硫回收工艺,在硫回收率、尾气达标、装置投资费用等方面更具优势。介绍了超优克劳斯硫回收的工艺原理、技术特点以及国内装置的建设概况;将超优克劳斯与其他硫横回收工艺的相对投资和效益进行了比较。结果表明,该工艺不仅适用于现有克劳斯装置的技术改造,也适用于新建装置;在不改变克劳斯工艺基本特点及没有进一步尾气处理的情况下,可将硫回收率提高到99．4％以上。     

硫回收装置尾气处理技术在煤化工装置中的改进与应用

针对传统克劳斯法硫回收装置(简称传统硫回收装置)工艺流程长、投资高、操作复杂、运行费用高、硫回收尾气中硫化物含量不稳定等问题,对传统硫回收装置进行改进。改进后的硫回收装置具有流程简单、设备少、占地小、投资省、操作简便、运行成本低、回收硫黄纯度高、尾气中污染物排放浓度超低等特点,满足环保要求,经济效益、环保效益明显。     

低氮氧燃烧器在硫回收装置的应用

2015年4月29日国家环境保护部发布《石油炼制工业污染物排放标准》(GB31570-2015)等六项国家污染物排放标准,新排放标准对硫回收装置NOx的排放提出了明确限值要求。硫回收装置作为化工厂的环保装置,减少NOx的排放十分必要,某石化公司硫回收装置尾气焚烧使用DUIKER低氮氧燃烧器。研究NOx产生原理及减排措施,剖析DUIKER低氮氧燃烧器的结构、原理及操作应用,总结分析某石化公司硫回收装置DUIKER低氮氧燃烧器六个月的运行情况,得到结论表明硫回收装置尾气焚烧炉使用DUIKER低氮氧燃烧器有效地减少了NOx排放。     

变压吸附制氮尾气回收用于石灰石富氧助燃技术研究

三友集团氯碱公司利用变压吸附技术制备氮气,同时排放富氧尾气,排放的富氧尾气是氧气浓度在30.5%的洁净气体。我公司利用新工艺、新技术、新装置将这部分富氧尾气回收并用于石灰石煅烧富氧助燃,不仅实现了废弃资源的回收再利用,同时还提高了石灰窑单窑能力及石灰石的活性,石焦消耗有所降低。年可节约液氧约9 600t,实现利润总额达642万元/年。     

硫回收装置尾气处理系统氨法脱硫工艺的技术经济分析

神华宁煤集团400万t/a煤制油项目硫回收装置尾气处理系统采用氨法脱硫工艺。介绍了氨法脱硫工艺的工艺流程和工艺特点,并以传统的SCOT脱硫工艺为参照,进行了投资、消耗和产出等方面的技术经济分析。结果表明,氨法脱硫工艺具有工艺流程简单、便于操作维护等优点,在煤化工硫回收装置尾气脱硫领域具有良好的应用前景。     

硫回收及尾气处理工艺综述

主要介绍了硫回收尾气处理工艺的基本原理、工艺技术特点及近期技术进展,并与国内常用的工艺进行技术经济性比较。针对我国硫回收装置规模较小,操作水平偏低的现状,提出了适于我国国情的技术改造意见,为硫回收及尾气处理工艺技术的选择提供参考。     

超优克劳斯工艺在煤化工硫回收中的应用

超优克劳斯工艺是一项先进、成熟的硫回收技术,具有流程简单、操作灵活、安全可靠、运行费用低、应用规模不限、使用范围广、硫回收率高等优点,成为近10年来发展最快的硫回收工艺技术之一。在不改变克劳斯工艺基本特点及没有进一步尾气处理的情况下,可将硫回收率提高到99.4%以上。在新建硫磺回收装置建设及原有老装置改造方面,超优克劳斯硫回收工艺都有一定的推广应用价值。本文介绍了超优克劳斯硫回收工艺原理、技术特点及国内装置建设概况,并对该工艺在国内相关领域的发展前景作出了展望。     

带HCR^TM尾气处理的新建硫回收装置简介

介绍Duna炼油厂6^#硫回收装置的设计、施工和试运行。该装置硫回收能力为90t／d,包括克劳斯硫回收装置、基于HCR^TM工艺的尾气处理装置和酸性水汽提装置。其主要特点为：硫回收率大于99．9％,尾气加氢反应器采用低温催化剂,胺液再生系统与原有4^#、5^#硫回收装置共用,通过克劳斯废热锅炉和焚烧炉废热锅炉回收废热生产高压和中压蒸汽,完全烧氨,酸性气去热反应器。在试运行期间,装置所有性能达到保证值。     

Solid oxide electrolysis cell 3D simulation using artificial neural network for cathodic process description

An artificial neural network (ANN) is used for modeling electrochemical process in a porous cathode of SOEC. The neural network has the following input parameters: the overvoltage, the hydrogen and steam composition at electrode/electrolyte interface. Data for training and validating the ANN simulator is extracted from a validated model. Once the model is identified, the ANN can be successfully used for simulating electrochemical behavior of a SOEC electrode. The analytical expression of the network has been implemented in a three-dimensional multiphysics model of SOEC serial repeat unit (SRU). The expression takes into account micro-scale effects in the macro-scale model with a minimum cost of computation time. Gas flow velocity, species concentrations, current density and temperature distributions through the SRU have been calculated. It has been shown that the ANN could be used in the macro-scale model giving coherent results.     

Heat Integration in Straight‐Through Sulfur Recovery Units to Increase Net High‐Pressure Steam Production

Energy conservation is of paramount importance in oil and gas industries. Sulfur recovery units (SRUs) in oil and gas industries are required to meet the stringent environmental emission regulations, and are often viewed as production costs. They are normally net energy exporters and a considerable portion of heat is recovered as high‐pressure steam. However, SRUs processing lean acid gas streams require significant amounts of acid gas and air preheating before they enter the reaction furnace. Some portion of the generated high‐pressure steam is used in preheating these streams. This reduces the overall net high‐pressure steam generated from the SRU. Here, heat integration is used and an existing SRU facility is retrofitted such that there is an increase in net high‐pressure steam production. Seven new heat‐integrated SRU configurations are proposed, and key aspects such as net high‐pressure steam production, investment costs, and payback period for each of the new retrofitted configurations are compared.     

An investigation of reaction furnace temperatures and sulfur recovery

In a modern day sulfur recovery unit (SRU), hydrogen sulfide (H₂S) is converted to elemental sulfur using a modified Claus unit. A process simulator called TSWEET has been used to consider the Claus process. The effect of the H₂S concentration, the H₂S/CO₂ ratio, the input air flow rate, the acid gas flow of the acid gas (AG) splitter and the temperature of the acid gas feed at three different oxygen concentrations (in the air input) on the main burner temperature have been studied. Also the effects of the tail gas ratio and the catalytic bed type on the sulfur recovery were studied. The bed temperatures were optimized in order to enhance the sulfur recovery for a given acid gas feed and air input. Initially when the fraction of AG splitter flow to the main burner was increased, the temperature of the main burner increased to a maximum but then decreased sharply when the flow fraction was further increased; this was true for all three concentrations of oxygen. However, if three other parameters (the concentration of H₂S, the ratio H₂S/CO₂ and the flow rate of air) were increased, the temperature of the main burner increased monotonically. This increase had different slopes depending on the oxygen concentration in the input air. But, by increasing the temperature of the acid gas feed, the temperature of the main burner decreased. In general, the concentration of oxygen in the input air into the Claus unit had little effect on the temperature of the main burner (This is true for all parameters). The optimal catalytic bed temperature, tail gas ratio and type of catalytic bed were also determined and these conditions are a minimum temperature of 300°C, a ratio of 2.0 and a hydrolysing Claus bed.     

Effectiveness of the Desulfurization of Coke-Oven Gas at PAO Magnitogorskii Metallurgicheskii Kombinat

To assess the capabilities of the desulfurization system for coke-oven gas in coking-product recovery shop 2 at PAO Magnitogorskii Metallurgicheskii Kombinat (MMK), the effectiveness of all stages in sulfur recovery unit (SRU) at the shop is analyzed. It is found that the capacity for catalytic conversion of hydrogen sulfide to sulfur is not being fully utilized. Its use would raise the temperature of both stages in the SRU’s R-6201 Claus reactor. The optimum temperature of the second catalytic stage of the R-6201/2 unit and maximum conversion to sulfur cannot be achieved because of the insufficient heat-exchanger efficiency resulting from surface deposits of sulfur. Observations at waste-heat boiler 1 of the elemental-sulfur production department in the copper plant of Norilsk Nickel’s Transpolar Division show that sulfur condensation on the heatexchanger surface decreases the heat transfer in the waste-heat boiler by 20–40%. Modification of the heating system for the second stage of the R-6201 Claus reactor in coking-product recovery shop 2 at PAO MMK by introducing a regulated bypass line is proposed.     

影响硫回收装置长周期运行的主要因素及对策

介绍了国内炼油厂硫回收装置的运行现状,论述了装置开停车造成的影响.着重介绍了镇海炼化2套70 kt/a硫回收装置和1套100 kt/a烧氨硫回收装置在长周期运行方面的经验;结合多年运行管理实践对影响装置长周期运行的主要因素进行了分析探讨,并提出相应对策.     

烟气排放控制技术的工艺现状

详细描述了LABSORB^TM再生式二氧化硫脱除工艺以及所用的EDV洗涤器设计。FCC装置可由一个简单的工艺采用：EDV洗涤器降低烟气中颗粒和SOx含量，不会引起堵塞或停车。该洗涤器可作为仅处理颗粒的设备(代替ESP)，当以后环保条例更严格时，也能转而处理SOx而不浪费任何组件。该洗涤器可使用LABSORB^TM工艺吸收剂，也可用苛性钠、碳酸钠、氢氧化镁甚至石灰为吸收剂。但二氧化硫含量较高时，LABSORB^TM可再生工艺可大幅度降低操作费用。LABSORB^TM工艺已成功地用于控制硫回收(SRU)装置的尾气排放，并用于控制全世界范围内22个FCC装置的排放，累计处理能力近158000m^3／d(1000000桶／d)。文中介绍用于FCC装置排放控制的苛性钠洗涤、可再生式洗涤以及常见的电除尘器(ESP)应用之间的差别，还详细描述这些系统及其除满足环保要求外的潜在优点。     

Pollutant monitoring in tail gas of sulfur recovery unit with statistical and soft computing models

In this article, data-driven models are developed for real time monitoring of sulfur dioxide and hydrogen sulfide in the tail gas stream of sulfur recovery unit (SRU). Statistical [partial least square (PLS), ridge regression (RR) and Gaussian process regression (GPR)] and soft computing models are constructed from plant data. The plant data were divided into training and validation sets using Kennard-Stone algorithm. All models are developed from the training data set. PLS model is designed using SIMPLS algorithm. Three different ridge parameter selection techniques are used to design the RR model. GPR model is designed using four hyper parameter selection methods. The soft computing models include fuzzy and neuro-fuzzy models. Prediction accuracy of all models is assessed by simulation with validation dataset. Simulation results show that the GPR model designed with marginal log likelihood maximization method has good prediction accuracy and outperforms the performance of all other models. The developed GPR model is also found to yield better prediction accuracy than some other models of the SRU proposed in the literature.     

化学链干重整联合制氢热力学分析及实验

提出了一种化学链甲烷干重整联合制氢工艺。该工艺由还原反应器、干重整反应器、蒸汽反应器和空气反应器组成，在实现制氢的同时获得可变H₂/CO比的合成气。借助ASPEN plus软件和小型流化床实验台，在等温条件下，温度900℃，采用Fe₂O₃/Al₂O₃载氧体，对该工艺进行热力学分析和实验验证。结果显示，当铁氧化物被还原至FeO/Fe时，干重整反应器内甲烷转化率可以达到98%，CO产率可以达到94%。干重整反应器中同时发生甲烷干重整和部分氧化反应，载氧体内部晶格氧可以有效降低积炭并提高合成气H₂/CO比。积炭发生于晶格氧消耗殆尽时。积炭进入蒸汽反应器，发生气化反应，降低氢气纯度。     

Enhanced selectivity and formation of ethylbenzene for acetophenone hydrogenation by adsorbed oxygen on Pd/SiO2

The effect of adsorbed oxygen for selectivity of acetophenone (AP) hydrogenation on Pd/SiO₂ catalyst at 298 K has been studied by means of gas phase acetophenone hydrogenation, infrared (IR) spectra, and temperature-programmed desorption. Acetophenone hydrogenation on reduced Pd/SiO₂ catalyst reveals a typical series reaction in which phenylethanol (PE) is the intermediate for ethylbenzene (EB) formation. The selectivity of the reaction is towards phenylethanol at low temperature. The oxidized Pd/SiO₂ catalyst exhibits very different catalytic selectivity with reduced catalyst. The selectivity of ethylbenzene can be significantly boosted to over 90%, even if the reaction approaches zero conversion, suggesting that phenylethanol needs not be an intermediate for production of ethylbenzene from acetophenone. The formation of ethylbenzene and phenylethanol on oxidized Pd may be controlled by a parallel reaction pathway. The numbers of adsorbed oxygen on Pd surface strongly dominate the rate of EB formation. The bulk Pd oxide cannot be reduced by hydrogen at 298 K, so the oxygen atoms in Pd bulk act a poison for AP hydrogenation, leading to deactivation of oxidized Pd catalyst. The adsorbed oxygen on Pd surface plays the important role that can activate the C---H bond of CH₃ group in acetophenone, leading to the formation of a new intermediate (perhaps acetophenone enolate). This intermediate is the key species that will be further hydrogenated to ethylbenzene.