高含硫天然气脱硫装置操作条件的优化

采用Aspen Plus流程模拟软件对高含硫天然气脱硫工艺流程进行了模拟和操作条件优化,以脱硫装置年利润为优化目标,主要操作条件为决策变量,净化气中H2S和CO2含量为约束条件,建立稳态优化模型。模拟结果表明,操作条件对脱硫净化效果影响由强至弱顺序为溶液循环量>吸收塔板数>吸收塔压力>吸收塔温度;脱硫装置能耗构成中蒸汽占6.36%,冷却器能耗占25.53%,机泵类电力能耗占8.11%;影响脱硫装置年利润的主要因素是净化气流量和操作费用,受溶液循环量、吸收塔塔板数和吸收塔压力影响,宜采用相对低的吸收塔压力和适当的吸收塔塔板数;在吸收塔塔板数14块、吸收塔压力6 MPa、溶液循环量23.26 Mmol/h的优化操作条件下,脱硫装置年利润最大值为1.01×109元,年操作费用为2.3×107元。

Optimization of Operating Conditions of High-Sulfur Gas Sweetening Unit

Process simulation and operating condition optimization for high-sulfur natural gas sweetening were conducted by using Aspen Plus simulation software.A steady state optimization model was established aiming at the annual profit of a sweetening unit with its main operating conditions as the variables and the concentrations of H2S and CO2in the treated gas as the constraints.The simulation results show that the order of the operating condition impact on the purification efficiency is as follows:solution circulation rate>absorber tray number>absorber pressure>absorber temperature.The constitution of energy consumption in the process is steam 66.36%,cooler 25.53% and pump 8.11%.Main factors affecting the annual profit of the sweetening unit are the treated gas flowrate and operating costs.Considering the effect of the solution circulation rate,absorber tray number and absorber pressure,relatively low absorber pressure and appropriate absorber tray number should be adopted in the process.The annual profit of the sweetening unit and annual operating costs are 1.01 billion Yuan and 23 million Yuan respectively under the optimized conditions of absorber tray number 14,absorber pressure 6 MPa and solution circulation rate 23.26 Mmol/h.