School of Mechatronic Engineering, Xian Technological University, Xian 710021, China.
School of Mechatronic Engineering, Xian Technological University, Xian 710021, China.
Sci Total Environ. 2021 Jan 20;753:141690. doi: 10.1016/j.scitotenv.2020.141690. Epub 2020 Aug 13.
Biomass, as a renewable energy source, has high potential for supplying the energy needs of modern societies. Gasification is a thermochemical route for converting biomass into combustible gas at high temperatures. The main purpose of the present study was to develop an Aspen Plus model of air-steam gasification of biomass (sawdust) to predict the gasification characteristics and performances. The prediction capability of the model was evaluated by comparison with experimental data obtained in a fluidized bed biomass gasifier. First, the influence of gasification temperature on gas composition, product yields and gasifier performances was investigated. The biomass feeding rate and air flow rate were set at~0.445 kg/h and 0.5 Nm/h, respectively, while the gasifier temperature was varied between 700 °C to 800 °C. With the increase of temperature, the gas yield (DGY) increased steadily from 1.72 to 2.0 Nm/kg, while the HHV of the produced syngas (HHV) increased initially from 5.38 to 5.73 MJ/Nm and then decreased to 5.69 MJ/Nm. After determining optimal temperature (800 °C), the influence of equivalence ratio (ER) and steam/biomass ratio (S/B) on gasification characteristics, dry gas yield (DGY) and tar yield (TRY) was studied. As ER increased from 0.19 to 0.23, TRY decreased from 9.13 g/Nm to 8.45 g/Nm. In contrast, DGY initially increased from 2.02 Nm/kg to 2.43 Nm/kg as ER increased from 0.19 to 0.21 and then dropped to 2.24 Nm/kg at ER of 0.23. An increase in S/B from 0.61 to 2.7 also resulted in a slight increase in HHV; however, TRY showed a decreasing trend (from 9.65 g/Nm to 8.95 g/Nm). The results showed that the model developed in this paper is a promising tool for simulating the biomass gasification at various operating conditions.
生物质作为一种可再生能源，具有为现代社会提供能源需求的巨大潜力。气化是一种在高温下将生物质转化为可燃气体的热化学途径。本研究的主要目的是开发一种基于 Aspen Plus 的生物质（木屑）空气-蒸汽气化模型，以预测气化特性和性能。通过与流化床生物质气化炉获得的实验数据进行比较来评估模型的预测能力。首先，研究了气化温度对气体成分、产品收率和气化炉性能的影响。生物质进料速率和空气流量分别设定为~0.445kg/h 和 0.5Nm/h，而气化炉温度在 700°C 至 800°C 之间变化。随着温度的升高，气体产率（DGY）从 1.72 稳定增加到 2.0Nm/kg，而产生的合成气的高热值（HHV）最初从 5.38 增加到 5.73MJ/Nm，然后降低到 5.69MJ/Nm。在确定最佳温度（800°C）后，研究了当量比（ER）和蒸汽/生物质比（S/B）对气化特性、干气产率（DGY）和焦油产率（TRY）的影响。随着 ER 从 0.19 增加到 0.23，TRY 从 9.13g/Nm 降低到 8.45g/Nm。相反，随着 ER 从 0.19 增加到 0.21，DGY 从 2.02Nm/kg 增加到 2.43Nm/kg，然后在 ER 为 0.23 时降至 2.24Nm/kg。S/B 从 0.61 增加到 2.7 也导致 HHV 略有增加；然而，TRY 呈下降趋势（从 9.65g/Nm 降至 8.95g/Nm）。结果表明，本文开发的模型是在各种操作条件下模拟生物质气化的有前途的工具。
