A huge renewable energy project is currently conducted and making its way in Iowa State University that utilizes cellulosic biomass as sources of synthesis gas or SynGas, which can be processed further to desired type of fuel.
In a previous article, Iowa engineers are using pyrolysis-microbial bioconversion tandem in converting biomass to bio-oil to biofuels. In this research project, Iowa engineers combine two thermochemical processes to convert biomass into a hydrogen/carbon monoxide mixture, also called as synthesis gas.
First step is pyrolysis, a thermochemical decomposition of an organic material in the absence of oxygen, but in the presence of high temperature. Researchers subject cellulosic biomass products in a pyrolysis machine producing molasses-like smelling brown oil called bio-oil.
Second step is gasification, another thermochemical process that utilizes heat, pressure, and an oxygen source (e.g. steam or air) to break down complex organic materials directly into simple gases comprising carbon monoxide, carbon dioxide, and hydrogen. Iowa engineers have fabricated their own bio-oil gasifier whose main components are:
- Pressure vessel – stainless steel pipe, 6 inches in diameter, 3-foot long, max pressure = 700 psi
- Reactor – a pipe made of silicon carbide (same material as in sand or emery paper) that is fitted inside the pressure vessel, max operating temperature = 1,800 oF or about 982 oC
- Nozzle – mixes bio-oil with oxygen and sprays it into the top of the reactor
The bio-oil produced in pyrolysis machine is sprayed into the top of reactor producing a hydrogen/carbon monoxide gas mixture or SynGas.
The project does not end here as they are also going to develop the following: (1) a computer simulation model of bio-oil gasification to understand and predict the effects of changes in temperatures, pressure, and biomass; (2) a systems simulation tool to enable examination of technical and economic implications of bio-oil gasification; and (3) a virtual reality model of a full-size plant to enable the researchers to foresee problems and improve a plant before the actual construction.
This is a huge, visionary project for Iowa as these goals are all focused towards developing a new biorenewables landscape, where biomass will be transported for conversion to SynGas.