MOST- Novel microwave fluidized bed reactor for catalytic pyrolysis of biomass residues and biochar applications

据估计，不列颠哥伦比亚省每年有3000万吨森林残留物，可以转化为高价值的液体生物燃料或生物化学品，以抵消与收集和预处理相关的高昂成本。生物质热解是生物质在无氧条件下的热裂解过程，将生物质转化为生物油和生物炭。生物油可以进一步升级为液体燃料。热解已被认为是将生物质残渣转化为生物燃料(柴油和喷气燃料)和生物化学品(如碳、醇)的一条很有前途的途径。然而，生物油和生物炭的质量较低，给升级和应用带来了挑战。具体地说，生物油含氧量高，在升级操作中消耗大量氢气，占与化石燃料制氢相关的整个液体生物燃料供应链温室气体排放总量的66%以上。生物炭的劣质也使其无法用作土壤肥料和冶金过程中的还原剂。在这个加拿大和台湾的合作项目中，我们将开发一种新型的微波沸腾床反应器和低成本的天然催化剂，将生物质就地热解为生物油和生物炭。由于生物质颗粒独特的内部微波加热，以及有机蒸汽在高温催化剂表面的原位微波辅助催化裂化，生物油的质量可以显著提高，这在我们的初步试验中体现为低氧含量、低酸度和低粘度。由于内部的快速加热，产生了具有多孔结构和高比表面积的生物炭颗粒，它们与剩余的天然催化剂作为营养物质一起成为一种高价值的碳基肥料，具有高保水和高养分的能力。即将开发的新型催化反应器系统将把丰富的生物质残渣转化为优质生物油和生物炭，为加拿大的生物经济做出贡献，为实现国家温室气体减排目标做出贡献。

There are estimated 30 million tonnes of forest residues available each year at British Columbia, which can be converted to high-value liquid biofuels or biochemicals to offset the high cost associated with collection and pretreatment. Pyrolysis is a thermal cracking process of biomass in the absence of oxygen, which converts biomass to bio-oil and biochar. Bio-oil can be further upgraded to liquid fuels. Pyrolysis has been identified as a promising pathway for converting biomass residues to biofuels (diesel and jet fuel) and biochemicals (e.g. carbon, alcohols). The low quality of bio-oil and biochar, however, imposes challenges in upgrading and application. Specifically, the high oxygen content in bio-oil consumes large amount hydrogen in upgrading operation, which accounts for more than 66% of total greenhouse gas emissions over the whole liquid biofuel supply chain associated with hydrogen production from fossil fuels. The poor quality of biochar also surrenders its use as fertilizer for soil applications and as a reducing agent in metallurgical processes.In this Canada-Taiwan collaborative project, we will develop a novel microwave fluidized bed reactor and low-cost natural catalysts to in-situ pyrolyze biomass to bio-oil and biochar. Due to the unique internal microwave heating of biomass particles, and in-situ microwave-assisted catalytic cracking of organic vapours on hot catalyst surface, bio-oil quality can be improved significantly, as reflected by low oxygen content, low acidity and viscosity in our preliminary tests. Due to the internal rapid heating, the biochar particles of much porous structure and thus high specific surface area are created, which in conjunction with remaining natural catalysts as nutrients serve as a high-value carbon-based fertilizer with high water and nutrient holding capacity. The novel catalytic reactor system to be developed will convert abundant biomass residues to high-quality bio-oil and biochar, contributing to the Canadian bioeconomy, and contribute to meeting the national greenhouse emission reduction target.