276149 Aspen Simulation of Mobile Biomass to Liquid Facility the Beauti-Fuel Concept

Wednesday, October 31, 2012: 3:00 PM
306 (Convention Center )
Xinying Liu1, Bilal Patel1, Diane Hildebrandt2 and David Glasser3, (1)Centre of Material and Process Synthesis, University of the Witwatersrand, Johannesburg, South Africa, (2)Centre of Material and Process Synthesis (COMPS), University of the Witwatersrand, Johannesburg, South Africa, (3)Chemical Engineering, University of the Witwatersrand, Johannesburg, South Africa

The BeauTi-fueL facility is a mobile biomass to liquid facility, where the key equipment of the biomass to liquid process is placed into a commercial container and can be transported to a biomass site for liquid fuel production.  This facility can be used to process the biomass such as agriculture and forestry waste as well as mulniciple solid waste, to convert them into energy products and can be useful for energy needed remote area.  In the facility, biomass is fed into a plasma gasifier.  The gas existing the gasifier is then cooled and cleaned before sent to the Fischer Tropsch synthesis unit.  Liquid hydrocarbons formed in the Fischer Tropsch Synthesis is knocked out in the cooling and separation system and the tail gas with light hydrocarbons and unreacted CO and H2 is sent to a gas engine to generate electricity.  The electricity generated is to be used for the process itself.
The reason why a plasma gasifier was selected was because of its compactness and low tar formation because of the high temperature achieved.  The gasification chamber of the plasma gasifier with the needed capacity is small and can be fit into the container, where the size of the fixed bed gasifier and fluidized gasifier are all too large for this situation.  The disadvantage of using a plasma gasifier is it utilizes a high quality energy form, which is electricity, to provide energy needed for the gasification process.  This raises the question of the overall energy efficiency of the whole process.
An aspen simulation is conducted on this process concept at the claimed capacity of 1 barrel per day liquid hydrocarbon production.  Process conditions such as air feeding rate, air enrichment, plasma gasification operation temperature and pressure, the Fischer Tropsch synthesis operation pressure, syngas conversion, hydrocarbon selectivity and the gas engine efficiency are studied.  It is found that with the optimized process condition and the right biomass feed, only 1 dry ton per day biomass fed is needed for 1 barrel per day production.

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