Design and performance evaluation of dry cleaning process for syngas

Coal gasification is one of the most promising options for clean, efficient and continuous power generation, though little progress has been made towards its commercialisation. One of the main hurdles of the commercialisation is reliability of the syngas cleaning process involving separation of critical impurities which can adversely affect the downstream process, and may result in plant shutdown. For example, failure of particulate capturing operation could have instant effect on downstream turbine, catalytic membrane, fuel cell and CO2 separation, therefore hot filtration is considered as the most critical process step in the gas cleaning process. Failure of sulphur, chlorine, alkali and trace element capture steps may also cause serious damage to the downstream processes but the effect will be noticeable after a relatively longer period of operation. During this period it could be possible to take some corrective actions, either manually or through an automatic control system, to prevent the damage. An automatic control system for particulate system could also be suggested to prevent the damage during filter failure but this would also demand installation of an additional backup filtration unit to continue the operation while failed unit is bypassed for repair. Considering these factors, the reliability of gas cleaning process at reasonable costs appears to be the biggest challenge for the commercialisation of the gasification technologies. A laboratory scale dry gas cleaning unit has been developed and tested at CSIRO to address some of these challenges. This paper illustrates some of the performance results obtained from the tests prior to detailed scale-up studies to be undertaken. © 2011 Elsevier Ltd. All rights reserved.