A critical review of syngas cleaning technologies - fundamental limitations and practical problems

The importance of syngas cleaning has driven research in this area for over two decades but so far a robust and completely reliable technology has not been developed especially for gas cleaning over 600 degrees C to achieve higher efficiencies. The greatest evidence of this is continuation of research and development to improve particulate filtration, various sorbents and associated equipment. Although significant improvement has been made in these gas cleaning technologies in the past few years there still seems to be a long way to go to achieve complete reliability of these systems which have never been tested successfully in a real integrated gasification (IG) based system environment. The question then arises as to whether these conventional gas cleaning technologies will ever be perfected. This raises a few secondary questions such as what are the hurdles in the development of these technologies. Is there any fundamental limitation with the concept behind conventional gas cleaning technology? What are the practical problems these conventional technologies face and are unable to cope with? This paper summarizes the research conducted at the Centre for Low Emission Technology and CSIRO Energy Technology over the past year and presents a brief summary of current status of syngas cleaning technologies particularly of particulate removal systems and a review of practical problems and limitations faced by these gas cleaning systems. These problems have been qualitatively analyzed to evaluate if there is any link between these practical problems and fundamental limitations with the basic concept behind these gas cleaning technologies. Recommendations are also made to overcome these fundamental limitations. (C) 2007 Elsevier B.V. All rights reserved.