Adaptability Analysis And Operating Parameter Optimization Of A Natural Gas Desulfurization Unit

As the old gas field in east Sichuan has entered the middle and late stage of development,the quality conditions of raw material gas have changed greatly.Meanwhile,in recent years,the number of new Wells with high sulfur content has increased,and the proportion of high sulfur content gas has increased year by year.As a result,the quality conditions of the raw material gas entering the purification plant in this region may deviate from the design value,including the changes of acidic components in the raw material gas,as well as the changes of temperature,pressure and treatment capacity of the raw material.In addition,the production capacity of gas field is decreasing year by year,which makes the load of purification plants in this region generally low.This article in view of the problems in the region a significant researches on the purification plant,the purification plant since its launch in 2005,operating in good condition,but with the change of the east Sichuan old gas fields development,purification plant since 2013 remain in the original design value rate of feed gas below 60%,the low load operation of the long-term,makes part of the equipment is large in the car,phenomenon,cause the increase of energy consumption,operation parameters deviated from the original design work,increase caused by vibration,fault increases,the overhaul is frequent,affect the normal operation of device.At the same time,the quality of raw gas deviates from the original design value,and the production energy consumption and chemical raw material consumption are large,resulting in the increase of unit operating cost.To solve above problems,this paper proposes the purification plant in desulfurization unit system modeling,equipment adaptability analysis,operation parameters optimization,influence factors analysis,proposed plant under low load operation of the optimal operating parameters,to realize saving energy and reducing consumption,in order to adapt purification plant air fluctuations and new GB index change and optimize adjustment to provide strong support.By putting forward the research idea of solving the existing problems of the purification plant,it lays a solid foundation for the whole optimization and adjustment of the old gas field purification plant in east Sichuan.This paper makes a comprehensive analysis of the purification device,and studies the adaptability of the desulfurization device on the change of raw gas,hoping to ensure the stability of production operation by adjusting operating parameters.Through accounting analysis,the existing equipment of purification plant can be better used to improve the low-load operation state of purification plant and adapt to the change of raw gas quality.Specific research contents are as follows:?1?Study on flow simulation of natural gas desulfurization unit.A process unit simulation model was established for the main single equipment in the natural gas desulfurization system,and ProMax chemical simulation software was optimized.The optimization modeling of natural gas desulfurization device was realized by dividing each unit in the process and selecting modules for the device.?2?Analysis and research on the adaptability of desulfurization process based on process model.According to the changes of acid composition of raw gas,temperature of raw gas,pressure of raw gas and quantity of raw gas,the adaptability of desulfurization device is analyzed by changing the inlet position and circulating quantity of lean amine liquid.Based on the design-exper mathematical statistics software,the nonlinear relationship fitting between the circulating amount of amine liquid and each parameter is carried out to realize the sensitivity analysis of multi-parameter changes and to complete the adaptability analysis under the interaction of multi-parameter of natural gas desulfurization device.?3?Sensitivity analysis and research on operating parameters of desulfurization unit.Four operating parameters which have obvious influence on purification effect and energy consumption were selected:amine liquid circulation quantity,number of absorption tower plate,pressure of absorption tower and inlet temperature of lean liquid.The User-Defined test Design method was adopted to conduct the test Design,and the influence analysis of purification effect and energy consumption was completed.The response surface analysis was conducted with design-exper,and the polynomial fitting between the four factors and purification effect and energy consumption was completed.?4?Study on optimization of desulfurization device operating parameters.Two optimization schemes are adopted.Method 1:use design-exper optimization module to predict the optimal value of operating parameters;Scheme 2:set up an energy consumption optimization model based on bp-ga to optimize operating parameters.By comparing the optimization results of the two schemes,the optimal value with better effect and lower energy consumption is selected.The research results show that:?1?ProMax simulation software was selected to build the simulation model of natural gas desulfurization device process,and the model was checked based on the actual production data on the site.The error of key operating parameters was less than 11.2%,which laid a foundation for further research on the adaptability of the device and the optimal operating parameters;?2?According to temperament of feed gas condition deviates from the value of the design problem,develop the desulfurizer adaptability analysis research,determine the amine liquid is55 m³/h and maximum circulation absorption tower plate number 16 and under the condition of maximum desulphurization device handling limit,when the H₂S content in the feed gas is 12g/m³,the raw material should be less than 13.5?temperature degree,the pressure should be greater than 4.7 MPa,the maximum capacity of 290×10⁴ m³/d;?3?By conducting desulfurization device influence parameter sensitivity analysis,The importance order of influencing factors of H₂S removal effect was determined:Amine liquid circulating quantity>absorption tower plate number>absorption tower pressure>lean liquid inlet temperature,The importance order of influencing factors of CO₂ removal effect was determined:Circulating amount of amine liquid>absorption tower pressure>lean liquid inlet temperature>absorption tower plate number;When the interaction between the factors is considered,the circulation amount of amine liquid and the number of absorption tower plates have an extremely significant linear influence on the purification effect,the square and cubic influence are significant,the temperature of absorption tower has an extremely significant linear influence on the purification effect,and the four factors have an extremely significant influence on the energy consumption of the device.?4?In order to solve the problem of low load operation of the current device,the operation parameters of the device are optimized by using Design-Exper and BP-GA respectively.The results show that the operation based on BP-GA optimized operational parameters can achieve better purification effect and lower energy consumption.That is,the circulating amount of amine liquid is 26.75m³/h,the number of absorption tower plates is 16,the pressure of absorption tower is 5.98MPa,and the temperature of absorption tower is 24.48?,which can reduce energy consumption by 18.22%.Apply thesis research conclusion to the scene and found the device after purification acidic fraction and total sulfur content in gas is far lower than the new standard requirement,can in time according to the temperament of feed gas conditions change,make appropriate operation adjustment,realize stable production load 50⁶0%done,parameters optimization system is running after years to save power consumption by 16.8%,save gas consumption by 19.2%,for the purification plant production running cost savings.Apply thesis research conclusion to the scene and found the device after purification acidic fraction and total sulfur content in gas is far lower than the new standard requirement,can in time according to the temperament of feed gas conditions change,make appropriate operation adjustment,realize stable production load 50⁶0%done,parameters optimization system is running after years to save power consumption by 16.8%,save gas consumption by 19.2%,for the purification plant production running cost saving...