高级检索

    基于不同气化剂的生物质气化制氢工艺模拟

    Process simulation of biomass gasification for hydrogen production with different agents

    • 摘要: 气化剂种类显著影响生物质气化过程中H2产率。为系统比较不同气化剂的制氢效果,通过Aspen Plus软件建立了玉米秸秆气化制氢的流程模拟模型,使用不同的气化剂(空气、氧气、空气–水蒸气、氧气–水蒸气)模拟了玉米秸秆气化制氢工艺,系统分析了温度、当量比、水料比等相关参数对H2产量的影响,并进一步对不同气化方案进行了经济性评估。结果表明:与单一使用空气或氧气作为气化剂相比,加入水蒸气的联合气化对于H2生成均有促进作用。在所有气化剂条件下,随着气化温度升高,H2体积分数均增加,在900 ℃下保持稳定,温度增加使CO2和CH4体积分数持续下降,LHV和H2产率持续增加。随着当量比的增加(0.25~0.34),H2与CO物质的量比整体增加,H2体积分数和LHV呈现下降趋势,氧气–水蒸气条件下H2体积分数下降趋势最为明显。随着水料比增加(0~0.8),H2和CO2体积分数增加,LHV显著增加,CO和CH4含量降低,氧气–水蒸气联合气化条件下H2体积分数整体高于空气–水蒸气联合气化条件下。整体上,相同条件下氧气–水蒸气联合气化制氢效果最佳,在气化温度900 ℃、当量比为0.28、水料比为0.6时,H2体积分数和产率分别可达56%和126 g/kg。经济性分析表明,尽管氧气–水蒸气气化在制氢效果上占优,但其设备与氧气制备成本较高;相比之下,空气–水蒸气气化因运行成本较低而更具经济性优势,其平准化制氢成本可低至11.7元/kg,显示出良好的工业应用潜力。

       

      Abstract: Gasification agents significantly affect H2 yield during biomass gasification process. To systematically compare the hydrogen production efficiency of different gasification agents, this study established a process simulation model for hydrogen production from corn straw gasification using Aspen Plus software. Different gasification agents (air, oxygen, air-steam, oxygen-steam) were used to simulate the H2 production process of corn stover gasification. The effects of temperature, equivalence ratio, and steam to biomass ratio on H2 production were systematically analyzed, and economic evaluations on different gasification schemes were further conducted. The results indicated that, compared to using air or oxygen alone as the gasification agent, the combined gasification with steam addition promoted the production of H2. Under all gasification conditions, as the gasification temperature increased, the volume fraction of H2 increased and remained stable at 900 ℃. The increase in temperature led to a continuous decrease in the volume fraction of CO2 and CH4, while LHV and H2 yields continued to increase. As the equivalence ratio increased (0.25–0.34), the molar ratio of H2 to CO increased, while the proportion of H2 and LHV showed a decreasing trend. The most significant decrease in H2 volume fraction was observed under oxygen-steam conditions. As the steam to biomass ratio increased (0–0.8), the volume fraction of H2 and CO2 increased, LHV significantly increased, and the volume fraction of CO and CH4 decreased. The overall volume fraction of H2 under oxygen-steam combined gasification conditions was higher than that under air-steam combined gasification conditions. Overall, under the same conditions, oxygen-steam combined gasification had the best hydrogen production effect. When the gasification temperature was 900 ℃, the equivalence ratio was 0.28, and the steam to biomass ratio was 0.6, the volume fraction and yield of H2 could reach 56% and 126 g/kg, respectively. According to the economic analysis, although oxygen-steam gasification has a greater hydrogen production efficiency, its equipment and oxygen preparation costs are relatively high. In contrast, air-steam gasification offers economic advantages due to its lower operating costs. Its levelized hydrogen production cost can be as low as 11.7 yuan/kg, indicating good potential for industrial application.

       

    /

    返回文章
    返回