Investigating Three Different Models for Simulation of the Thermal Stage of an Industrial Split-Flow SRU Based on Equilibrium-Kinetic Approach with Heat Loss

2018 ◽  
Vol 14 (1) ◽  
Author(s):  
Mohammad Hossein Kardan ◽  
Reza Eslamloueyan
Keyword(s):  
Kinetic Model ◽  
Heat Loss ◽  
Conversion Efficiency ◽  
Waste Heat ◽  
Molar Ratio ◽  
Percentage Error ◽  
Sulfur Recovery ◽  
Waste Heat Boiler ◽  
Split Flow ◽  
Reaction Furnace

Abstract Modified Claus process is the most important process that recovers elemental sulfur from H2S. The thermal stage of sulfur recovery unit (SRU), including the reaction furnace (RF) and waste heat boiler (WHB), plays a critically important role in sulfur recovery percentage of the unit. In this article, three methods including kinetic (PFR model), equilibrium and equilibrium-kinetic models have been investigated in order to predict the reaction furnace effluent conditions. The comparison of results with industrial data shows that kinetic model (for whole the thermal stage) is the most accurate model for simulation of the thermal stage of the industrial split-flow SRU. Mean absolute percentage error for the considered kinetic model is 4.59 %. For the first time, the consequences of considering heat loss from the reaction furnace on calculated molar flows are studied. The results show that considering heat loss only affects better prediction of some effluent molar flow rates such as CO and SO2, and its effect is not significant on the results. Eventually the effects of feed preheating on some important parameters like sulfur conversion efficiency, H2S to SO2 molar ratio and important effluent molar flows are investigated. The results indicate that feed preheating will reduce the sulfur conversion efficiency. It is also noticeable that by reducing the feed temperature to 490 K, H2S/SO2 molar ratio reaches to its optimum value of 2.

scholarly journals Kinetic Reactions Modeling and Optimization of Claus Process

2020 ◽  
Author(s):  
Muhammad Arslan Zahid ◽  
Faisal Ali ◽  
Muhammad Mubashir ◽  
Faheem Iqbal
Keyword(s):  
Waste Heat ◽  
Aspen Plus ◽  
H2 Production ◽  
Sulfur Recovery ◽  
Waste Heat Boiler ◽  
Ammonia Gas ◽  
Claus Process ◽  
Simulation And Optimization ◽  
Catalyst Life ◽  
Reaction Furnace

There are many pollution and environment problem in the human ecosystem. There are different methods are used to removal of sulfur from sour gases for example Basic Claus process and Modified Claus process . There are different chemical software are used for simulation and optimization of Claus process for example Aspen Plus and Chemcad ECT. The Gibbs free energy method is introduced and model of Claus process. There are new parameter are introduced in reaction furnace to reduce the error from 33% to 7 %. The waste heat boiler is installed at the reaction furnace in which high pressure stream is produced and study the decomposition the hydrogen sulphide. The new rate of reaction is introduced of the enhancement of H2 production in chemical process. The simulation of reaction furnace in Aspen plus software is the maximum utilization of process. Due to suitable operating condition of reaction furnace is caused the maximum destruction of ammonia gas in the reactor. When we are increasing the oxygen concentration and temperature of feed is causing decreasing the ammonia production in reaction furnace. It is below than acceptance value of ammonia is 150 ppm in the reaction furnace. The presence of oxygen components, Sulfur oxide, hydroxide components are effect on decreasing the amount of ammonia in furnace and temperature is about at 1350⁰C. It is noted that when the production of sulfur recovery is decrease in Claus process and the production of carbon monoxide is increase in the thermal section at the existence. Now we are work on parametric studies of furnace that could be causes the production of ammonia destruction and CO emission in the Claus process. Due to optimize the reaction furnace parameter are help to get large of sulfur production, ammonia gas destruction, increased the catalyst life and decreased of dangerous gases.

A Means of Avoiding Sulfur Recovery Reaction Furnace Fired Tube Boiler Failures

2009 ◽  
Author(s):  
Mike Porter ◽  
Dennis Martens ◽  
Sean McGuffie ◽  
John Wheeler
Keyword(s):  
Heat Flux ◽  
Waste Heat ◽  
Local Heat ◽  
Sulfur Recovery ◽  
Steam Generation ◽  
Waste Heat Boiler ◽  
Flux Limit ◽  
Local Water ◽  
Reaction Furnace ◽  
Tube Failure

One of the common causes of premature tube failure in fired tube boilers — technically described as film boiling — is overheating of the tubes caused by steam blanketing. Current literature contains a significant amount of information on this problem, but not much in the way of definitive guidance for avoiding the problem. General “rules of thumb” are available for identifying the heat flux limit required to avoid the problem as in Martens et al [1]. Unfortunately, the values presented by different sources are often in disagreement. This paper will look at a sulfur recovery unit (SRU) Claus waste heat boiler application and, through the use of Computational Fluid Dynamics (CFD), develop a means of predicting the conditions that lead to steam blanketing and resultant tube failure. Local heat flux conditions at gas side discontinuities (such as the tube inlet ceramic ferrule terminations) combined with associated local water side steam entrainment, and steam generation with coupled velocity effects are discussed.

Development of an Online Soft Analyzer for the Continuous Analysis of BTEX Emissions from the Furnace of Sulfur Recovery Units

2021 ◽  
Author(s):  
Satyadileep Dara ◽  
Salisu Ibrahim ◽  
Abhijeet Raj ◽  
Ibrahim Khan ◽  
Eisa Al Jenaibi
Keyword(s):  
Kinetic Model ◽  
Soft Sensor ◽  
Sulfur Recovery ◽  
Furnace Temperature ◽  
Fuel Gas ◽  
Gas Processing ◽  
Wide Range ◽  
Gas Consumption ◽  
Reaction Furnace ◽  
Co Emission

Abstract The oxidation of Benzene, Toluene, Ethylbenzene, and Xylenes (BTEX) in the furnace of SRUs at high temperature is an effective solution to prevent Claus catalyst deactivation in the downstream catalytic converters. However, the existing SRUs do not have the means to monitor BTEX emissions from Claus furnace due to lack of commercial online analyzers in the market. This often leads to excessive temperatures up to 1150 °C in the furnace to ensure BTEX destruction. Such high temperatures increase fuel gas consumption and CO emission and reduce sulfur recovery efficiency. To obtain continuous BTEX indication at the furnace exit, an online BTEX soft sensor model is developed to predict BTEX concentration at furnace exit. Subsequently, this soft sensor will be implemented in one of the SRUs of ADNOC Gas Processing. The BTEX soft sensor has been developed by constructing a compact kinetic model for aromatics destruction in the furnace based on the understanding of BTEX oxidation mechanisms derived using a detailed and well validated kinetic model developed previously. The kinetic model, including its rate parameters were incorporated into Hysys/Sulsim software, where both the reaction furnace and catalytic converters were simulated. The BTEX soft sensor has been validated with plant data from different ADNOC Gas Processing SRU trains under a wide range of feed conditions (particularly, with varying relative concentrations of H2S, CO2, and hydrocarbons in acid gas feed) in order to ensure its robustness and versatile predictive accuracy. The model predicts BTEX emissions from the reaction furnace under a wide range of operating conditions in the furnace with deviation not exceeding +/- 5 ppm. It also predicts the reaction furnace temperature (with a deviation of +/- 5%) and species composition from the furnace exit within a reasonable error margin. Presently, the model is in the process of being deployed in one of the SRUs of ADNO Gas Processing as an online soft sensor, where it can read the feed conditions, predict the BTEX exit concentration and write this value to the DCS. Thus, plant operators can monitor BTEX exit concentration on continuous basis and use it as a reliable basis to lower fuel gas co-firing rate in the furnace to achieve optimum furnace temperature that provide efficient BTEX destruction and low CO emission. The online soft analyzer, when deployed in SRU, will continuously predict BTEX emission from SRU furnace with high accuracy, which cannot be done experimentally in the plant or reliably using most of the existing commercial software. This approach can be used to seek favorable means of optimizing BTEX destruction to enhance sulfur recovery, while decreasing fuel gas consumption and carbon footprint in sulfur recovery units to reduce operating cost.

Development of Coal Partial Gasification and Combustion System

2004 ◽  
Author(s):  
Yaoxin Liu ◽  
Libin Yang ◽  
Mengxiang Fang ◽  
Guanyi Chen ◽  
Zhongyang Luo ◽  
...  
Keyword(s):  
Conversion Efficiency ◽  
Pilot Plant ◽  
Sulfur Removal ◽  
Test Facility ◽  
Molar Ratio ◽  
Fuel Conversion ◽  
Heating Value ◽  
Pilot Plant Test ◽  
Plant Test ◽  
Partial Gasification

A new system using combined coal gasification and combustion has been developed for clean and high efficient utilization of coal. Following are the processes. The coal is first partially gasified and the produced fuel gas is then used for industrial purpose or as a fuel for a gas turbine. The char residue from the gasifier is burned in a circulating fluidized bed combustor to generate steam for power generation. For having the experimental investigation, a 1MW pilot plant test facility has been erected. Experiments on coal partial gasification with air, and recycle gas have been made on the 1 MW pilot plant test facility. The results show that, with air as gasification agent, the system can produce 4–5MJ/Nm3 low heating value dry gas and fuel conversion efficiency attains 50–70% in the gasifier, and residue 20–40% converted in the combustor and total conversion efficiency in the system is over 90%. In the gasifier, the carbon conversion efficiency increases with the bed temperature and the air blown temperature. CaCO3 has an effective effect for sulfur removal in the gasifier. The sulfur removal efficiency attains 85% with Ca/S molar ratio 2.5. The system can produce 12–14MJ/Nm3 middle heating value day gas by using high temperature circulation solid as heat carrier and recycle gas or steam as gasification media, but the fuel conversion efficiency only attain 30–40% in the gasifier and most of fuel energy is converted in the combustor. CaCO3 has an obvious effect on tar cracking and H2S removal. The sulfur removal efficiency attains 80% with Ca/S molar ratio 2.5.

scholarly journals Optimization design of thermal system for industrial waste heat power generation

2021 ◽  
Vol 261 ◽  
pp. 01047
Author(s):  
Fengchang Sun ◽  
Shiyue Li ◽  
Zhonghua Bai ◽  
Changhai Miao ◽  
Xiaochuan Deng ◽  
...  
Keyword(s):  
Power Generation ◽  
Industrial Waste ◽  
Optimization Design ◽  
Waste Heat ◽  
Design Method ◽  
Utilization Rate ◽  
Thermal System ◽  
Heat Power ◽  
Waste Heat Boiler ◽  
Industrial Waste Heat

In order to improve the utilization rate of industrial waste heat and improve the fine design level of waste heat power station, this paper constructs the mathematical model of waste heat boiler and steam turbine, and puts forward the optimization design method of thermal system of waste heat power generation project. By using typical cases, it is proved that there is the optimal design pressure of HRSG, which makes the power generation of the system maximum, and provides a method to improve the power generation of HRSG.

scholarly journals STUDY OF THE OXIDATION PROCESS OF NITROGEN OXIDES BY OZONE

2021 ◽  
pp. 62-70
Author(s):  
I.A. Volchyn ◽  
O.M. Kolomiets ◽  
S.V. Mezin ◽  
A.O. Yasynetskyi
Keyword(s):  
Nitrogen Oxides ◽  
Conversion Efficiency ◽  
Power Plants ◽  
Oxidation Process ◽  
Thermal Power ◽  
Nitrogen Monoxide ◽  
Molar Ratio ◽  
Gas Temperature ◽  
Gas Treatment ◽  
Industrial Enterprises

The need to reduce emissions of pollutants, in particular nitrogen oxides, as required by regulations in Ukraine, requires the use of modern technologies and methods for waste gas treatment at industrial enterprises. This is especially true of thermal power plants, which are powerful sources of nitrogen oxide emissions. The technological part of the wet or semi-dry method of purification is the area for the oxidation of nitrogen oxides to obtain easily soluble compounds. The paper presents the results of a study of the process of ozone oxidation of nitrogen oxides in a chemical reactor. Data for the analysis of the process were obtained by performing physical experiments on a laboratory installation and related calculations on a mathematical model. Studies of the oxidation process have shown that the required amount of ozone depends not only on the content of nitrogen monoxide, but also on the content of nitrogen dioxide. The process of conversion of nitrogen monoxide to a satisfactory level occurs at the initial value of the molar ratio of ozone to nitrogen monoxide in the range of 1.5…2. The conversion efficiency of nitrogen monoxide reaches 90% at a gas temperature less than 100 °C. To achieve high conversion efficiency at gas temperatures above 100 °C, it is necessary to increase the initial ozone content when the molar ratio exceeds 2. The analysis shows that the conversion efficiency of nitric oxide largely depends on the residence time of the gas mixture in the reaction zone. Due to lack of time under certain conditions, the efficiency decreases by approximately 46%. To increase it, it is necessary to accelerate the rate of oxidation reactions due to better mixing of gases by turbulence of the flow in the oxidizing reactor. Bibl. 6, Fig. 6, Tab. 3.

scholarly journals Exceptional thermoelectric performance in Mg3Sb0.6Bi1.4 for low-grade waste heat recovery

2019 ◽  
Vol 12 (3) ◽  
pp. 965-971 ◽  
Author(s):  
Kazuki Imasato ◽  
Stephen Dongmin Kang ◽  
G. Jeffrey Snyder
Keyword(s):  
Conversion Efficiency ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Thermoelectric Performance ◽  
Type Material ◽  
Low Grade ◽  
Thermoelectric Conversion

An n-type material with intrinsically higher thermoelectric conversion efficiency than Bi2Te3 in the low-grade waste-heat range has finally been developed.

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