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SIMULATION OF THERMOCHEMICAL BIOMASS CONVERSION PROCESSES

Objective

THE AIM OF THE PROJECT IS TO OBTAIN A QUANTITATIVE RANKING IN ECONOMIC TERMS AMONG THE VARIOUS PROCESSES FOR PRODUCING LIQUID FUELS FROM BIOMASS UNDER CONDITIONS TYPICAL OF THOSE APPLYING IN THE EUROPEAN COMMUNITY.
A technical and economic study of the conversion of renewable feedstocks to liquid fuels has been initiated. The main objective was to identify and evaluate all alternative technologies for liquid fuel production from biomass, and solid wastes, in order to identify the more promising technologies and research and development needs. The methodology adopted is to construct a robust technoeconomic computer simulation of the whole range of thermochemical, biochemical and physical conversion processes. Each of the processes is divided into process steps, each process step being defined as a self contained processing operation, and a model is constructed of each step, calculating the material balance, energy balance and capital cost. Whole processes can then be constructed from the individual step models and the economics of each process evaluated. Some process steps are well established and commercially available, and state of the art technology is used in the model. Other steps, however, are still at the research or development stage and need to be evaluated to identify the more technically and economically promising alternatives. This aids identification of further research and development needs.

The full range of technologies for liquid fuel production from renewable feedstocks have been examined in a technical and economic evaluation in order to identify the most promising technologies. The technologies considered were indirect thermochemical liquefaction (ie via gasification) to produce methanol, fuel alcohol or hydrocarbon fuels and fermentation to produce ethanol. Feedstocks considered are wood, refusederived fuel, straw, wheat and sugar beet.

In order to carry out the evaluation, a computer model has been developed, based on a unit process approach. Each unit operation is modelled as a process step, the model calculating the mass balance, energy balance and operating cost of the unit process. The results from the process step models are then combined to generate the mass balance, energy balance, capital cost and operating cost for the total process.
THIS IS AN ECONOMIC MODELLING PROJECT WHICH WILL BE CARRIED OUT IN THREE OVERLAPPING PHASES OVER A PERIOD OF THIRTY MONTHS. IT WILL BE SUPPORTED BY SUB-CONTRACTS WITH CJB, PARSONS WHITMORE AND DR. J. COOMBS.
PHASE A OF THE PROJECT WILL ATTEMPT TO ASSEMBLE A TECHNICAL AND ECONOMIC DATA BASE ON BIOMASS PROCESSING TO LIQUID FUELS. BIOMASS RAW MATERIALS AND POSSIBLE LIQUID PRODUCTS WILL BE LISTED AND REPORTED SCHEMES WILL BE BROKEN DOWN INTO THEIR COMPONENT STEPS FROM PRETREATMENT THROUGH CONVERSION TO REFINING. CONVERSION CONCEPTS TO RECEIVE PARTICULAR ATTENTION INCLUDE: DIRECT LIQUEFACTION OF BIOMASS, GASIFICATION/SYNTHESIS, PYROLYSIS AND FERMENTATION.
IN PHASE B PRACTICAL CONCEPTS FOR BIOMASS CONVERSION TO LIQUID FUELS IN THE COMMUNITY WILL BE PROPOSED ON THE BASIS OF THE DATA COLLECTED. CONCEPTUAL FLOW SHEETS WILL BE DRAWN AND PERFORMANCE AND CAPITAL COST MODELS WILL BE WRITTEN FOR EACH PROCESS STEP. OVERALL PERFORMANCE AND CAPITAL COST MODELS WILL BE DERIVED FOR EACH CONCEPT BY ASSEMBLING THE SMALLER MODELS FOR PROCESS STEPS AND A PRODUCTION COST MODEL WILL BE ADDED.
IN PHASE C A SET OF CONCEPTS WILL BE ASSIGNED TO EACH PRACTICAL CASE FOR CONVERTING BIOMASS TO LIQUID FUEL AND CONCEPTS WILL BE RANKED IN ORDER OF DESIRABILITY WITH PRODUCTION COST AS THE OBJECTIVE FUNCTION USING THE MODELS DERIVED IN PHASE B. THE SENSITIVITY OF THESE RESULTS WILL BE TESTED FOR LIKELY ERRORS IN ASSUMPTIONS WITH REGARD TO FEEDSTOCK COST, SCALE OF OPERATION AND PRODUCT SLATE. THE RESULTS OBTAINED WILL ALSO BE VALIDATED AGAINST THE LITERATURE AND AGAINST RESULTS OBTAINED USING OTHER SIMULATION PACKAGES..

Funding Scheme

CSC - Cost-sharing contracts

Coordinator

ASTON UNIVERSITY
Address
Aston Triangle
Birmingham
United Kingdom