Development of Integrated QFD/MCDM Framework for Optimal Selection of Gasifier Reactor for Crop Residue Gasification in Ghana

Abstract

A comprehensive methodological approach taken into account concerns of end users, optimal technical engineering parameters is proposed in this study to select optimal gasifier reactor type for the gasification of crop residues in Ghana.  Eleven technical/economic user requirements based on the existing challenges of the gasification system in Ghana were identified. The Analytical Hierarchy Process (AHP) was used to determine the weight of importance of each user requirement. Thirteen gasifiers operating and design engineering parameters were identified. A Quality Function Deployment (QFD)/Multi-Criteria Decision-Making techniques (MCDM) methodological approach for the optimal selection of gasifier reactor using the user requirement, engineering parameters and seven gasifier reactor types was developed. Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) was used to rank the various gasifier types based on the thirteen technical parameters and corresponding weights as determined from the QFD. Low tar content, use of multiple feedstocks and high syngas quality with relative weights of importance of 0.28, 0.14 and 0.13 respectively were identified to be the three most important user requirement in the selection of optimal gasifier for crop residue gasification in Ghana. Similarly, based on the outcome of the QFD framework, feedstock moisture content, gasifier operating temperature and feedstock particle size were identified to be the three most important gasifier engineering parameters. The results of the study revealed that, stratified downdraft gasifier reactor is the optimal gasifier type with the required engineering characteristics for crop residue gasification in Ghana.