Abstract:

Under the "Dual Carbon" initiative, biomass stands out as a zero-carbon or even negative carbon resource with significant development potential. Through pyrolysis and gasification technologies, biomass can be transformed into syngas, which serves as a feedstock for fuel cells or can be further converted into high-value products such as methanol, dimethyl ether, and aviation fuel. However, the presence of tar and particulate matter (PM) in syngas represents a major challenge in its downstream processing. In traditional biomass gasification systems, the gasification, tar cracking/reforming, and gas-solid separation units operate independently. As a consequence, the raw syngas has to be cooled down to a temperature below 300℃ to match the operating temperature conditions of the dust removal equipment. This cooling process gives rise to issues including tar condensation and blockage, equipment corrosion, and heat loss. To tackle these challenges, this study introduces a novel approach that employs a membrane reactor integrated with a catalyst for the in-situ purification of syngas during poplar wood gasification. Silicon carbide (SiC) membranes were employed to capture PM, and Fe/Ni-loaded carbon-based catalysts were used to catalyze the cracking/reforming of the tar volatiles. The research revealed that at an optimal temperature of 800℃ and a steam-to-biomass mass ratio (S/B) of 1.5, employing a SiC membrane reactor in conjunction with activated carbon-based catalysts loaded with Fe-Ni, the yield of syngas was 56mmol/g, and the molar ratio of hydrogen to carbon monoxide in the syngas was approximately 1.9; the tar yield from the gasification of poplar wood was reduced to 8.4g/m³ of syngas, with a tar conversion of 91.6%; the production of PM was minimized to 0.08g/m³ of syngas, and the PM removal efficiency was 89.0%, aligning with the technical specifications for syngas used in solid oxide fuel cells.

Key words: biomass gasification, membrane reactor, carbon-based catalyst, clean syngas

摘要：

在“双碳”背景下，生物质作为一种零碳甚至负碳资源具有巨大的发展潜力。通过热解气化技术，生物质可用于生产合成气，合成气可用于燃料电池，或进一步加氢可生产甲醇、二甲醚、航煤等高附加值产品。然而，合成气中含有的焦油和固体颗粒（particulate Matter，PM）是其在下游加工中面临的一大挑战。在传统生物质气化系统中，气化、焦油重整和气固分离单元独立运行，导致粗合成气需降温至300℃以下以适应除尘设备的操作温度要求，引发焦油冷凝堵塞、设备腐蚀及热损失问题。为了解决这些问题，本文提出在杨木气化反应中利用膜反应器与催化剂耦合实现合成气原位净化。其中，碳化硅（SiC）膜用于截留挥发分中的PM，铁/镍负载的碳基催化剂用于催化裂解焦油组分。研究发现，在最佳温度800℃、水蒸气与生物质的质量比为1.5时，利用SiC膜反应器耦合Fe-Ni负载的活化后的碳基催化剂，合成气收率为56mmol/g（H₂/CO~1.9），合成气中的焦油收率为8.4g/m³，焦油脱除率为91.6%；固体颗粒产量为0.08g/m³，颗粒截留率为89.0%，该合成气组成符合固体氧化物燃料电池用合成气技术规范。

关键词: 生物质气化, 膜反应器, 碳基催化剂, 清洁合成气