A PROBABILISTIC MODEL FOR THE MODIFIED CLAUS PROCESS

A model is proposed for simulation of an industrial Claus unit with a straight-through configuration and two catalytic reactors. Process design evaluation based on deterministic calculations does not take into account the uncertainties associated with the input variables. The probabilistic simulation method was applied in the Claus model to obtain an impression of how some of these inaccuracies influence plant performance. The application was tested experimentally to confirm its validity, then used for control purposes.     

Use of new reaction kinetics for COS formation to achieve reduced sulfur emissions from claus plants

A simulation study of COS formation in the tubes of the waste heat boiler (WHB) located just after the reaction furnace of a Claus plant is reported. First, the kinetics of the COS forming reaction were obtained from a recently completed experimental program in our laboratory. The predictions for COS formation from the newly developed kinetic model were compared with the data from an actual industrial waste heat boiler and found to be in good agreement. The simulation results showed that up to a 50% reduction in the COS production may be achieved by operating the WHB at the maximum allowable gas mass velocity in the WHB tubes coupled with the use of a smaller diameter tube. These reductions have major implications on the overall sulfur recovery from Claus plants.     

Modelling a circulating fluidized bed riser reactor with gas—solids downflow at the wall

A predictive model was developed for the fully developed zone of a circulating fluidized bed (CFB) riser reactor operating in the fast fluidization regime that overcomes limitations of existing models. The model accounts for the upward flow of gas and solids in the core and downward flow of the two phases in the annulus. Additionally, a numerical solution methodology for the simulation of a riser reactor employing the hydrodynamic model was devised. A simulation was performed using the fast, main Claus reaction to demonstrate the effects of backmixing in the fast fluidization regime. It was found that the molar flow rates of the reactants leaving a fast fluidized CFB riser reactor were significantly higher than those leaving an identical reactor operating in the pneumatic transport regime.     

SIMULATING VARIOUS SCHEMES OF THE CLAUS PROCESS

An interactive program based on the Gibbs free energy minimization and the FLOWTRAN system analysis was written to simulate various schemes of the Claus process. Dew point calculation and feedback control loops were provided. Certain species are treated as inerts in units like condensers, reheaters, and the waste heat boiler, Simulation of the Claus process air demand and simulation of two Claus plants (including a commercial one) were presented and the results analyzed.     

克劳斯硫回收系统通用流程模拟软件CLAUS

介绍了克劳斯硫回收系统通用流程模拟软件－ＣＬＡＵＳ，通过对实际流程进行操作型与设计型的模拟计算，证明该软件符合生产实际，可以用于工程设计和实际工况的模拟分析与优化。     

HYSYS软件模拟克劳斯法硫磺回收工艺

HYSYS软件因为物性数据库不完整,对克劳斯（Claus）法硫磺回收工艺不能进行有效模拟。通过完善HYSYS软件自带数据库中的部分物性数据,HYSYS软件亦可对克劳斯法硫磺回收工艺进行高精度模拟。本文利用完善后的HYSYS软件对中国石化上海高桥分公司原油适应性改造工程环保项目硫磺回收装置和中国石油克拉玛依石化公司硫磺回收装置扩能改造项目进行了工艺模拟,结果与SULSIM软件模拟结果进行比较,其计算偏差在允许范围内。     

超级克劳斯硫磺回收技术浅析及展望

超级克劳斯工艺是一项先进、成熟的硫磺回收技术,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20年来发展最快的硫磺回收工艺技术之一。在新建硫磺回收装置及原有老装置改造方面,超级克劳斯硫磺回收工艺都有广阔的应用前景。介绍了超级克劳斯及传统克劳斯、超优克劳斯硫磺回收工艺原理,叙述了超级克劳斯工艺的发展,并对该工艺在国内相关领域的应用前景进行展望。     

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。     

Kinetic modelling of a fluidized bed claus plant

A kinetic model of a fluidized bed Claus reactor was developed using the Modified Bubble Assemblage Model (MBAM) to establish the practical implications of fluid bed technology for this new application. Simulations predicted that a two stage sub-dewpoint fluidized bed Claus plant is capable of achieving a recovery efficiency of 97.1%, which is comparable to a conventional three stage fixed bed plant, but considerably less than the overall equilibrium conversion of 99.5%. Conversion is limited by gas-bypassing, particularly in the downstream sub-dewpoint reactor. In the fluidized bed process, about half the catalyst is required and the pressure drop is significantly lower compared with a conventional plant of equivalent capacity. Moreover, the capital cost estimate for a two reactor fluid bed Claus plant (200 t/d sulphur) was estimated to be $20 million (Can) which is within 10% of a conventional plant.     

超级克劳斯装置的工艺和控制

介绍了超级克劳斯装置的工艺特点,阐述了燃烧炉控制系统和氧化空气控制系统的设计意图,将该装置与常规克劳斯工艺进行了比较。结果表明,超级克劳斯装置硫回收率超过99.5％;从化学反应的根本上实现了对催化剂活性的保护和对SO2、H2S的抑制。     

基于Aspen Plus的克劳斯硫回收过程模拟

采用Aspen P lus工艺模拟计算软件模拟了克劳斯硫回收工艺过程,模拟数据与硫回收专用模拟软件的标定数据吻合较好;在此基础上,利用Aspen P lus模块化分析功能,研究了克劳斯工艺的关键数据对工艺过程的影响,其结论与实际生产过程相符合;结果表明,基于Aspen P lus的克劳斯硫回收过程模拟,对设计计算和生产...     

Fluidized bed Claus reactor studies

Fluidized bed studies have been performed on the Claus reaction to determine whether the conversion efficiency of the Claus process could be improved by replacing conventional fixed bed reactors with fluidized bed reactors. Various idealized Claus plants, incorporating fluidized bed technology, were simulated using the equilibrium constant method. The results of the simulation indicated that, for feed gases consisting of pure H₂S, sulphur conversions in excess of 99% are attainable by using a Claus furnace and two fluidized bed reactors in series. To substantiate the theoretical predictions, experimental studies were performed using a single fluidized bed reactor (0.1 m I.D.) containing Kaiser alumina S-501 catalyst. The effects of temperature (150–300°C), flow rates (15–30 l min⁻¹), feed composition (0.06 < H₂S < 18%, 0.03 < SO₂ < 9%, 73 < N₂ < 99.91%) and bed height (0.12, 0.25 m) on the sulphur conversion were examined. The experimental results showed the same general trends as the theoretical predictions but the measured sulphur conversions exceed the theoretical values by up to 8%.     

影响Claus尾气加氢催化剂性能的动力学研究

实验室通过对低温Claus尾气加氢催化剂动力学研究,考察了Claus尾气含硫化合物加氢反应的规律。通过对影响Claus尾气加氢催化剂性能的主要因素分析,阐述了过程气中烃类反应导致的催化剂积炭速率与烃含量、催化剂使用温度、催化剂运转时间的关系;通过使用XRD、SEM等技术手段,对热老化前后Claus尾气加氢催化剂晶相、金属分散、孔结构等性质进行测试和表征。从不同角度研究、探讨影响催化剂性能的因素,对于低温Claus尾气加氢催化剂及其配套工艺的开发和应用具有指导意义。     

Thermal Decomposition Of Carbonyl Sulfide At Temperatures Encountered In The Front End Of Modified Claus Plants

Understanding the kinetics of the formation and consumption of COS and CS₂ in the front end of the modified Claus process will be a significant step towards reducing the environmental impact of these plants. Specifically, homogeneous intrinsic rate expressions are needed for engineering design and simulation, which will lead to new, optimized ways of operating these plants. Hence, a high-temperature kinetic study of the COS decomposition reaction was carried out. Experiments were performed with inlet COS compositions in the range of 0.20–2.33 mol%, with pressures at 101–150 kPa and temperatures at 800–1100°C; these conditions cover the conditions typically encountered in the front end of the modified Claus process. The experimental results showed that COS conversion is dependent on the inlet concentration of COS, which contrasts with previously reported higher temperature studies. Finally, the COS decomposition kinetics were modeled as the sum of two reactions, which provided a satisfactory representation of experimental data.     

Thermal Decomposition Of Carbonyl Sulfide At Temperatures Encountered In The Front End Of Modified Claus Plants

Understanding the kinetics of the formation and consumption of COS and CS₂ in the front end of the modified Claus process will be a significant step towards reducing the environmental impact of these plants. Specifically, homogeneous intrinsic rate expressions are needed for engineering design and simulation, which will lead to new, optimized ways of operating these plants. Hence, a high-temperature kinetic study of the COS decomposition reaction was carried out. Experiments were performed with inlet COS compositions in the range of 0.20-2.33 mol%, with pressures at 101-150 kPa and temperatures at 800-1100°C; these conditions cover the conditions typically encountered in the front end of the modified Claus process. The experimental results showed that COS conversion is dependent on the inlet concentration of COS, which contrasts with previously reported higher temperature studies. Finally, the COS decomposition kinetics were modeled as the sum of two reactions, which provided a satisfactory representation of experimental data.     

CPS 硫磺回收工艺在塔中某处理厂的应用

塔中某处理厂硫磺回收采用分流法低温克劳斯工艺,通过一级常规克劳斯和三级低温克劳斯反应完成单质硫的回收和尾气的处理,保证硫收率达到99.25％以上及尾气排放合格。文中对装置的工艺特点进行简单介绍,并对生产过程中遇到的问题与应对措施进行分析和说明,充分证明了CPS硫磺回收工艺非常适合该处理厂的实际情况。     

Analysis of the deactivation of Claus alumina catalyst during its industrial exploitation

Change in the activity of AO-NKZ-2 (AO-MK-2) alumina catalyst in the Claus reaction and transformations of carbonyl sulfide during operation over four years in the Claus reactor at the Magnitogorsk Metallurgical Combine’s coke-oven gas purification shop were studied at an average temperature of 245–260°C and a volume velocity of ∼2000 h⁻¹. The rate constants of the Claus reactions and COS transformation were determined, and the changes in the active surface area of the catalyst were investigated. Fundamental discrepancies in the rate and deactivation mechanism of the Claus catalysts were revealed with respect to the reactions of the conversion of hydrogen sulfide and carbonyl sulfide.     

三级克劳斯及其改良硫磺回收工艺的应用

介绍了三级克劳斯、超级克劳斯和超优克劳斯硫磺回收装置的工艺流程、布置方案和工程实例;提出了工程设计中应注意的问题。     

脱除SO2并回收硫磺的冶炼烟气处理工艺

介绍用甲烷(天然气)直接还原技术使冶炼烟气中SO2生成元素硫的工艺研究。SO2直接还原法分2 步:在高温下用甲烷将部分SO2还原成S和H2S,然后未反应的SO2和H2S发生Claus转化反应生成S。研究发现, 在工业装置中还原反应器宜采用分批甲烷法进料,以避免烟灰的生成;另需严格控制各种物料的相对比例,以确保位于Claus转化系列的硫冷凝器排出的尾气中的H2S／SO2为2,从而优化工艺性能。另外试验发现,在不同的停留时间下,SO2转化率与反应温度的关系曲线变化趋势是相反的,因此必须根据具体的现场条件选择停留时间。Siirtec Nigi公司和Albera硫研究有限责任公司联合开发了一种CH4／SO2还原／Claus／HCRTM工艺,其总硫回收率可达到99％以上。试验确定了一组有价值的化学工程数据,可用于该工艺的工业装置设计。     

超级克劳斯工艺在天然气硫回收装置中的应用

介绍了克劳斯和超级克劳斯工艺的特点,从工艺流程、关键设备的选择和自动控制等方面介绍了超级克劳斯技术在硫回收装置中的应用。