Petroleum is responsible for 42% of U.S. energy-related carbon dioxide (CO2) emissions. Although use of low-carbon fuels is growing, the trend is too slow to reduce transportation dependence on petroleum-based fuels in a timely and significant manner. There is a need for transformational biofuels technologies that can convert abundant domestic biomass resources—such as the leaves, husks or stalks from corn—into transportation fuel. These technologies have the potential to substantially enhance U.S. economic and energy security.
Project Innovation + Advantages:
Iowa State University (ISU) will develop a catalytic autothermal pyrolysis (CAP) process for the production of aromatics and olefins that refiners blend into transportation fuels. Pyrolysis is the decomposition of substances by heating - the same process used to render wood into charcoal, caramelize sugar, and dry roast coffee beans. Traditionally, energy for pyrolysis is provided through indirect heat exchange, employing high temperature heat exchangers within reactors or conveying hot solids into reactors with the feedstock. This approach complicates the design and operation of reactors and requires a separate combustor to burn char, coke, or other fuel to generate the thermal energy. The ISU team plans to use an autothermal fluidized bed reactor, a specialized reactor where a gas is passed through solid granular material at high velocity. Air is used as the fluidizing gas to promote direct, partial combustion of biomass and pyrolysis products to supply the energy required for endothermic operation. This will replace indirect heating methods with direct heating within the reactor, simplifying the design and reducing capital cost while increasing throughput, improving catalyst life, and achieving product yield and quality similar to or greater than current processes. The team seeks to demonstrate CAP in the laboratory and pilot-scale reactors; identify optimal CAP operating conditions to maximize the yield of hydrocarbons; and develop engineering scaling relationships for CAP reactors to facilitate the design of commercial-scale CAP reactors.