Department of Mechanical Engineering, Urmia University, Urmia, Iran.
Department of Mechanical Engineering, Urmia University, Urmia, Iran.
Chemosphere. 2022 Jul;299:134408. doi: 10.1016/j.chemosphere.2022.134408. Epub 2022 Mar 24.
The issues of global plastic waste generation and demand for hydrogen energy can be simultaneously resolved by gasification process. In this regard, feasibility and efficiency of steam and air co-gasification of coal by incorporating five different and prevalent types of plastic waste were investigated in this modeling study. All steam and air coal/plastic waste co-gasification types were multi-objective optimized utilizing a response surface methodology. The best co-gasification types were selected using VIekriterijumsko KOmpromisno Rangiranje (VIKOR) analysis. Overall, the results showed that incorporating plastic waste into coal gasification improved hydrogen concentration in the syngas and increased normalized carbon dioxide production due to the high carbon content of plastic waste and activation of water-gas and CO shift reactions. VIKOR analysis revealed that steam coal/low density polyethylene was the best optimized co-gasification type with hydrogen concentration of 62.8 mol %, normalized carbon dioxide production of 2.60 g/mol, based on the feedstock entering the system, and energy efficiency of 76.6%. Increasing gasifier temperature enhanced hydrogen concentration and decreased normalized carbon dioxide production. The energy efficiency was markedly improved by increasing the moisture content and decreasing the ratio of steam/feedstock. This study confirmed the hypothesis of efficient utilization of plastic waste in coal/plastic waste co-gasification.
气化过程可以同时解决全球塑料废物产生和对氢能的需求问题。在这方面，本研究通过模拟研究考察了在蒸汽和空气中掺入 5 种不同且常见类型的塑料废物时煤的共气化的可行性和效率。利用响应面法对所有蒸汽和空气煤/塑料废物共气化类型进行了多目标优化。使用 VIekriterijumsko KOmpromisno Rangiranje (VIKOR) 分析选择最佳共气化类型。总体而言，结果表明，将塑料废物掺入煤气化可提高合成气中的氢气浓度，并由于塑料废物的高碳含量和水煤气及 CO 变换反应的活化作用而增加归一化二氧化碳的产量。VIKOR 分析表明，基于进入系统的原料，蒸汽煤/低密度聚乙烯是最佳优化的共气化类型，其氢气浓度为 62.8 mol%，归一化二氧化碳产量为 2.60 g/mol，能量效率为 76.6%。提高气化器温度可提高氢气浓度，降低归一化二氧化碳产量。通过增加水分含量和降低蒸汽/原料比，可显著提高能源效率。本研究证实了在煤/塑料废物共气化中有效利用塑料废物的假设。
