基于Aspen Plus的玉米秸秆与煤共气化模拟优化研究

Simulation and Optimization of Co-Gasification of Corn Stover and Coal Using Aspen Plus

摘要: 为妥善利用生物质秸秆和减少对传统能源利用方式的依赖，本文提出了玉米秸秆与煤共气化方案，利用Aspen Plus流程模拟软件对秸秆与煤共气化行为进行模拟研究，并对不同操作条件对合成气组分等因素进行了灵敏度分析，结果表明气化温度在750℃之前对模拟结果影响较大，气化压力和氧气流量的增加对模拟结果产生负面影响，而水蒸气流量对H₂体积分数和产量有积极作用，故结合以上规律，以合成气产率为正交优化目标，通过极差分析得到最佳操作条件，将玉米秸秆与煤炭比例设置为40:60，气化温度设置为723℃，气化压力设置为1 bar，气化剂中氧气流量为200 kg·h⁻¹，水蒸气补充流量为440.43 kg·h⁻¹。得到最优模拟结果，产气组分中H2占比29.72%，CO占比20.18%，CO₂占比6.49%，CH₄占比0.298%，氢气产量为78.21 kg·h⁻¹，气体产率2.923 Nm³·kg⁻¹。

Abstract: To effectively utilize biomass straw and reduce reliance on traditional energy sources, this study proposes a co-gasification scheme of corn straw and coal. The gasification behavior of straw and coal co-gasification is simulated using the Aspen Plus process simulation software. Sensitivity analysis is conducted on various operating conditions, focusing on the composition of synthesized gas. The re-sults indicate that gasification temperature has a significant impact on the simulation results below 750˚C. An increase in gasification pressure and oxygen flow rate has a detrimental effect on the simulation results, while steam flow rate has a positive influence on H₂ volume fraction and yield. By integrating these observations, and considering synthetic gas yield as the orthogonal optimization objective, the optimal operational conditions are determined through range analysis. The corn straw-to-coal ratio is set at 40:60, gasification temperature at 723˚C, gasification pressure at 1 bar, oxygen flow rate in the gasification agent at 200 kg·h⁻¹, and steam supplementation flow rate at 440.43 kg·h⁻¹. The optimal simulation results yield gas components with H₂ occupying 29.72%, CO occupying 20.18%, CO₂ occupying 6.49%, CH₄ occupying 0.298%. The hydrogen production rate is 78.21 kg·h⁻¹, and the gas yield is 2.923 Nm³·kg⁻¹.