Carmona Oscar M, Vederza Arnaldo, Morales R Andrés D, Lenis Yuhan A
Grupo de Investigación e Innovación en Energía (GIIEN), Institución Universitaria Pascual Bravo, Calle 73 No. 73 - 226, Medellín, 050034, Colombia.
Departamento de Ingeniería Industrial, Universidad Simón Bolívar, Carrera 59 No. 59-65, Barranquilla, 080002, Colombia.
Heliyon. 2024 Jul 23;10(15):e34781. doi: 10.1016/j.heliyon.2024.e34781. eCollection 2024 Aug 15.
Gasification is a thermochemical process that has gained significant interest in the field of biomass energy conversion. Despite the level of technological maturity of the process, the dynamic variation of the process as a result of changes in both the properties of the gasifying agent and biomass has not been analysed in sufficient depth. Therefore, the present study characterizes the process dynamically as a function of step-type changes in rice husk biomass moisture content and gasifying airflow. To identify stability conditions and the range for inducing disturbances, steady-state tests were carried out using a 3-factorial design. The experimental results demonstrate that within the tested range of airflow, the gasification process operates in the oxygen-limited zone. Despite increasing the airflow from 20 to 40 standard liters per minute (SLPM) and driving the reaction towards the combustion zone, the high temperatures achieved resulted in the gas reaching a peak Lower Heating Value (LHV) of 2.6 MJ/Nm3 and a gas power of 2.6 kW, with a Cold Gas Efficiency (CGE) of 62%. In contrast, the effect of biomass moisture content was negligible due to the thermal inertia of the reactor and the natural variation of the process. Dynamic evaluation revealed that the oxidation temperature and gas concentration were the variables that took the longest to return to stability after air disturbances. It took approximately 1200 s for the hydrogen (H) concentration to stabilize, while the gas power required about 300 s. No clear results were observed regarding the impact of the dynamic disturbance in moisture content, which varied between 12.3% w.t and 21.5% w.t.
气化是一种热化学过程，在生物质能转化领域引起了广泛关注。尽管该过程的技术成熟度较高，但由于气化剂和生物质特性的变化导致的过程动态变化尚未得到充分深入的分析。因此，本研究将该过程动态地表征为稻壳生物质水分含量和气化气流阶跃式变化的函数。为了确定稳定性条件和诱导干扰的范围，采用三因素设计进行了稳态测试。实验结果表明，在测试的气流范围内，气化过程在氧气受限区域运行。尽管将气流从每分钟20标准升增加到40标准升，并使反应朝着燃烧区进行，但达到的高温导致气体的低位热值（LHV）峰值达到2.6 MJ/Nm³，气体功率达到2.6 kW，冷煤气效率（CGE）为62%。相比之下，由于反应器的热惯性和过程的自然变化，生物质水分含量的影响可以忽略不计。动态评估表明，氧化温度和气体浓度是在空气干扰后恢复稳定所需时间最长的变量。氢气（H）浓度稳定大约需要1200秒，而气体功率大约需要300秒。对于水分含量在12.3%（重量）至21.5%（重量）之间变化的动态干扰影响，未观察到明确的结果。
