The fate of methane in a claus plant reaction furnace

Experimental kinetic data are reported for key side reactions occurring in the front end [i. e. the reaction furnace (RF) and the waste heat boiler (WHB)] of modified Claus plants used for sulfur recovery from the sour gases evolved in the treatment of natural gas. An extensive experimental study was conducted in a high temperature tubular reactor system for two important homogenous gas‐phase reactions. Firstly, experiments were carried out to study the oxidation of hydrogen sulfide and methane mixtures in the presence of oxygen. Secondly, the reaction between methane and sulfur dioxide was investigated experimentally. These results showed that methane was much less competitive for oxygen than hydrogen sulfide. Hence, in a partially oxidizing environment of a RF, data showed that methane reacted significantly with other major sulfur containing species, as secondary reactions, to form COS and especially CS². This is highly problematic from an environmental point of view.     

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.     

Sulphur recovery from sour gas by using a modified low-temperature Claus process on sepiolite

In order to introduce an alternative catalyst for the reduction at low temperature, 343–423 K, of the Claus process streams tail gas, the authors studied the performance of sepiolite, a natural, very abundant and cheap hydrated magnesium phylosilicate whose unique textural and structural characteristics confer the solid with the possibility of use as an adsorbent and catalyst. Apart from the effectiveness of the solid in catalysing the sulphur dioxide reduction by hydrogen sulphide, an expression for the reaction rate has been deduced from the analytical data. The kinetic expression tells about a mechanism in which the chemical reaction between adsorbed species is the controlling step of the process. Water present in the Claus stream as a reaction by-product is adsorbed on the substrate and plays an important role in the reaction kinetics. From deactivation experiments under mass control conditions a better performance of sepiolite with respect to γ-alumina is made apparent.     

制磷电炉设计选型与电炉能耗的关系探讨

以目前国内较为普遍的几种制磷电炉设计型式为例,重点从传热理论方面分析不同电极布置方式的制磷电炉对能耗的影响。结果表明,三相三电极电炉炉壳单位时间的热损失最小,其生产操作安全性、产品单位能耗都比三相六电极电炉优越。     

电石炉烟气回收利用的技术方案

介绍了用电石炉生产电石产生的烟气的回收和利用原理、工艺流程以及技术方案。经计算,2100℃的烟气降至100℃时可回收的热量约为1.44×106kJ/(t·电石);400℃的烟气降至100℃时可回收的热量约为1.9×105kJ/(t·电石);烟气净化后的气体经充分燃烧后放出热量约为5.4×106kJ/(t·电石)。     

高炉煤气特征组分分析及其对脱硫过程的影响研究进展

高炉煤气（BFG）作为炼铁过程中副产的可燃气体,具有明显的资源回收价值,但其同时存在热值低、成分复杂等问题。目前大多数研究集中在对羰基硫（COS）、硫化氢（H₂S）等有害成分的脱除,而鲜有对高炉煤气特征组分的研究或报道。研究者对高炉煤气特征组分的来源、生成路径等不明朗,导致在研究过程中忽略了煤气复杂组分的相互影响,很多技术在工业应用时问题频发。本文阐述并分析了高炉煤气特征组分的来源及生成路径,进而讨论了高炉煤气特征组分对脱硫过程的影响。高炉原料、燃料和空气在高温条件下经过复杂的化学反应,生成粉尘、N₂、O₂、CO、CO₂、H₂、CH₄、H₂O、HCl、HCN、硫化物等共同组成高炉荒煤气,荒煤气中的O₂、CO_x、H₂、H₂O、HCl、硫化物等化学成分对COS转化或H₂S脱除过程产生影响,导致催化剂中毒或转化率下降。本文通过分析探讨特征组分在高炉煤气产生和脱硫净化过程中的相互作用及影响规律,为超低排放背景下高炉煤气的净化和资源化提供方向和参考。     

基于均匀设计法的富氧底吹铜熔池熔炼炉热力学回归分析

找出系统用能的薄弱环节和造成低效率的原因,会对炼铜工业的发展造成深远的影响。本文针对富氧底吹铜熔池熔炼炉的结构特征,从热力学角度出发,依据富氧底吹铜熔池熔炼炉的冶金计算模型,结合实际的生产数据,选择富氧率、铜锍温度、烟气温度、炉渣温度、精矿种类为影响因素,基于均匀设计法,对影响富氧底吹铜熔池熔炼炉生产过程?效率的主要工艺参数进行回归分析,结果表明:在保证炉料间化学反应充分完全的条件下,富氧率和炉渣温度之间存在明显交互作用,随着富氧率或烟气温度减小,炉渣温度或铜锍温度增加,精矿品位增高,则富氧底吹铜熔池熔炼炉?效率增加,为整个富氧底吹铜熔池熔炼炉熔炼过程的节能降耗提供有利基础,并为智能集成决策提供了重要优化理论基础。     

蒸汽冷凝水闭式回收在焦化厂的研究与应用

本文叙述了蒸汽冷凝水闭式回收的意义以及主要优点,针对焦化厂的具体情况,对厂内几个用汽工段进行了冷凝水回收改造,项目实施后效果显著,既改善了现场环境又节约了能源。     

概论多相反应系统的开发与设计

论述了气－液、气－液－固三相淤浆床及涡流床、气－固相固定床、气－固相流化床等多相反应系统的工业应用。并介绍了国内反应工程工业实践成果的参考索引。     

煤制天然气酚氨回收工艺分析与探讨

废水处理问题是限制煤制天然气发展的主要问题，其中酚氨回收单元是影响整个废水处理流程平稳运行的关键因素。本文主要介绍了3种已工业化的酚氨回收工艺，通过分析酚氨回收工艺，发现酚氨回收单元主要存在以下几个共性问题：①总氨脱除效率低，氨产品中酚含量高；②萃取脱酚效率低。拟通过单元优化和工艺改造两方面对上述问题进行解决，因此对酚氨回收工艺提出了相应的优化方案：①增加脱氨塔塔底再沸器的加热负荷，在脱氨单元加入足量或过量的稀碱液，增加脱氨塔塔板与塔顶之间的距离以及在氨精制单元降低第三级分凝罐的操作温度和增设碱洗罐；②寻求高效的萃取剂，在萃取塔之前增设CO₂吸收塔。研究表明，上述优化方案有效地提高了总氨脱除率，降低了氨产品中酚含量，并提高了萃取剂的脱酚效率。     

集成NGL回收的新型天然气液化系统AP-XTM的概念设计与模拟分析

为提高液化天然气能量集成与设备共用水平,提出了一种基于大型AP-X^TM液化流程，综合气体过冷技术（GSP）的集成NGL（天然气凝液）回收工艺的天然气液化系统的概念设计。基于化工流程模拟软件Aspen HYSYS进行模拟和分析，将集成工艺多流股换热器性能、全流程的单位功耗和乙烷回收率作为衡量系统性能的三项指标。模拟和分析的结果表明，集成NGL回收的AP-X^TM液化工艺单位功耗降低至0.45 kW·h·(kg LNG)^-1，较单产系统能耗降低了6%，同时乙烷回收率达到93%，实现了NGL的高效分离。通过热力学分析、?分析和经济性分析得出本设计流程具有较高的性能和经济价值，可为天然气液化工艺的集成设计和技术改造提供指导借鉴。     

A novel conceptual design by integrating NGL recovery and LNG regasification processes for maximum energy savings

Natural gas liquids (NGL) recovery from shale gas needs large amounts of cold energy for cooling, while liquefied natural gas (LNG) regasification requires tremendous hot energy for heating. Thus, recycling the cold energy from LNG regasification process at a receiving terminal to assist the NGL recovery process has great economic benefits on both energy saving and high‐value product recovery. A novel conceptual design by integrating NGL recovery from shale gas and LNG regasification at receiving terminals has been developed. It first generates a process superstructure. Then, a simulation‐assisted mixed‐integer linear programming (MILP) model is developed and solved for the optimal process synthesis. Next, heat exchange network (HEN) design and analysis are performed to accomplish the maximum energy‐saving target. Finally, rigorous plant‐wide simulations are conducted to validate the feasibility and capability of the entire conceptual design coupling of separation and heat integration. © 2013 American Institute of Chemical Engineers AIChE J, 59: 4673–4685, 2013     

50m~3醇酸反应釜优化设计

介绍了国内j最大50 m~3醇酸反应釜设计理念和方法,2006年5月一次试车成功。2a多的运行实践表明:50 m~3大型醇酸反应釜具有均温、高效、节能、运行可靠、投资低、环保等优越性。据统计,用1台50 m~3替代2台25 m~3醇酸反应釜,每年增产醇酸树脂400 t,多创产值340万元;节约成本350万元,经济效益和社会效益显著。     

热交换器外壳冲压成形工艺及其模具设计要点

本文主要依据热交换器外壳所选材料的特点及其外形结构特点,分析许确定了合理的冲压成形工艺方案,同时财其成彤模具设计中的要点进行了重点阐述。     

浅析影响PTA装置母液回收的因素和处理

通过对PTA精制单元的工艺流程的分析,指出精制单元母液回收的影响因素,并提出解决的方案,以便装置的平稳运行。通过生产运行的优化操作来降低装置废料的产生,降低装置的单耗。结果表明母液的温度和设备的完好率等因素都会影响母液含固率的回收率。     

恩德炉煤灰处理印染废水中的有色染料研究

用不同种类酸对恩德炉煤灰进行预处理,并用于对染料单体进行脱色,探讨了加酸量、搅拌时间、加恩德炉煤灰量和温度对脱色率的影响。结果表明,硝酸处理的脱色效果较好,处理100 mL印染废水最适宜条件为:0.5 g恩德炉煤灰在室温下搅拌40 min。     

COSMO‐based computer‐aided molecular/mixture design: A focus on reaction solvents

In this article, we investigate reaction solvent design using COSMO‐RS thermodynamics in conjunction with computer‐aided molecular design (CAMD) techniques. CAMD using COSMO‐RS has the distinct advantage of being a method based in quantum chemistry, which allows for the incorporation of quantum‐level information about transition states, reactive intermediates, and other important species directly into CAMD problems. This work encompasses three main additions to our previous framework for solvent design (Austin et al., Chem Eng Sci. 2017;159:93–105): (1) altering the group contribution method to estimate hydrogen‐bonding and non‐hydrogen‐bonding σ‐profiles; (2) ab initio modeling of strong solute/solvent interactions such as H‐bonding or coordinate bonding; and (3) solving mixture design problems limited to common laboratory and industrial solvents. We apply this methodology to three diverse case studies: accelerating the reaction rate of a Menschutkin reaction, controlling the chemoselectivity of a lithiation reaction, and controlling the chemoselectivity of a nucleophilic aromatic substitution reaction. We report improved solvents/mixtures in all cases. © 2017 American Institute of Chemical Engineers AIChE J, 63: 104–122, 2018     

On the global and efficient solution of stochastic batch plant design problems

The presence of uncertainty in product demands of batch plant design formulations with fixed structure and continuous equipment sizes transforms them into large-scale nonconvex nonlinear programs. This paper describes recent developments towards the efficient solution of such mathematical models. Two global optimization algorthms, a specialized GOP algorithm and a reduced space branch and bound algorithm, are presented and applied to this class of batch plant design models. It is shown that, by taking advantage of the special structure of the resulting mathematical formulations, encouraging computational results can be obtained from both algorithms for problem sizes that would otherwise be practically unsolvable with conventional global optimization techniques. An efficient, specialized Gaussian quadrature technique is also described for the case of product demands following normal probability distribution functions with which reduced model size and improved estimation of the expected profit integral are achieved. These developments are tested on example problems from the literature covering single batch plant configuration with various scheduling policies and flexible configurations with alternative production sequences.