Vargas-Mira Alexander, Zuluaga-García Carlos, González-Delgado Ángel Darío
Chemical Engineering Department, Nanomaterials and Computer Aided Process Engineering Research Group (NIPAC), University of Cartagena, Avenida del Consulado St. 30, 130015 Cartagena de Indias, Colombia.
ACS Omega. 2019 Sep 10;4(13):15457-15470. doi: 10.1021/acsomega.9b01683. eCollection 2019 Sep 24.
Currently, the production of alternative fuels from renewable sources such as biomass has been increased in order to meet energy policies and reduce the environmental impacts of fossil fuels. This work is focused on hydrogen production from oil palm empty fruit bunches using different biomass gasification methods (direct gasification, indirect gasification, and supercritical water gasification) and purification technologies (selexol-based absorption and pressure swing adsorption). Six routes were selected based on these technologies and simulated using Aspen Plus software. Possible operating process improvements were suggested based on parametric sensitivity analysis by studying the effect of several variables on hydrogen production: gasification temperature, gasifying agent-to-biomass ratio, steam-to-carbon monoxide ratio, temperature of a high-temperature step reactor, and pressure in a hydrogen purification unit. The methodology of waste reduction algorithm was performed to assess the environmental impacts of each route. Results showed that hydrogen production was improved by increasing the gasification reaction temperature to 900 °C, oxygen-to-biomass ratio to 1.5, and pressure of purification stage to 10 atm for all routes. However, routes 1 and 2 presented a slight increase up to 0.7% in hydrogen yield using 1.5 mol O/mol biomass. The environmental assessment revealed that routes 3 and 4 exhibited the lowest toxicological and atmospheric environmental impacts because of the use of char generated in the gasification reaction for energy production. These results indicated that route 4 exhibited the best performance for producing hydrogen from an environmental viewpoint.
目前，为了满足能源政策并减少化石燃料对环境的影响，利用生物质等可再生资源生产替代燃料的产量有所增加。这项工作的重点是使用不同的生物质气化方法（直接气化、间接气化和超临界水气化）和净化技术（基于Selexol的吸收和变压吸附）从油棕空果串中制氢。基于这些技术选择了六条路线，并使用Aspen Plus软件进行了模拟。通过研究几个变量对氢气生产的影响：气化温度、气化剂与生物质的比例、蒸汽与一氧化碳的比例、高温步进反应器的温度以及氢气净化单元中的压力，基于参数敏感性分析提出了可能的操作工艺改进措施。采用废物减少算法的方法来评估每条路线的环境影响。结果表明，对于所有路线，将气化反应温度提高到900℃、氧与生物质的比例提高到1.5以及净化阶段的压力提高到10个大气压，氢气产量都会提高。然而，路线1和路线2在使用1.5摩尔氧/摩尔生物质时，氢气产率略有提高，最高可达0.7%。环境评估表明，由于将气化反应中产生的焦炭用于能源生产，路线3和路线4对毒理学和大气环境的影响最小。这些结果表明，从环境角度来看，路线4在制氢方面表现最佳。
