Modelling, simulation and design of an integrated radiant syngas cooler and steam methane reformer for use with coal gasification

Abstract

In this work, a novel process intensification design is proposed to integrate the Radiant Syngas Cooler (RSC) utilised to cool the coal-derived synthesis gas in entrained-bed gasifiers and a steam methane reformer (SMR). The feasibility of the proposed integrated system is analyzed by developing a rigorous, dynamic, multi-dimensional model and establishing design heuristics for the integrated system. Two different flow configurations are explored; co-current and counter-current. The simulation results show that the proposed concept is feasible that allows for methane conversions as high as 80% in co-current mode and 88% in counter-current mode. The results also demonstrate that the counter-current design, though with higher conversion and cooling duty provided when compared to co-current designs, is limited by the tube wall material limitations. Our analysis shows that the total avoided CO2 emissions is 13.3tonnes/h by using the proposed integrated configuration in place of an external reformer for the natural gas feed rates considered in this study. In addition, a sensitivity analysis is performed on key model assumptions and the resulting effect on the performance is assessed. The sensitivity results have helped identify key factors to consider prior to pilot-scale implementation and further improvement for agile designs; a one third reduction in tube length reduced pressure drop by as much as 50% but reduces methane conversion by 15% points, neglecting slag deposition on tubes over-predicts performance only by 3%, and a 10% change in gas emissivity calculations affects model prediction of performance by less than 1%.