Comparison of CO2 gasification reactivity and kinetics: petcoke, biomass and high ash coal

Abstract

It is desirable to exploit biomass energy along with coal and petcoke through gasification, and understanding the differences between petroleum coke (petcoke), coal and biomass gasification behaviour becomes very essential. Consequently, present investigation compares gasification components of petcoke, sawdust and high ash coal with their physico-chemical properties under isothermal conditions in CO2 atmosphere in the temperature range of 1173–1623 K. Physico-chemical characterisation includes proximate and ultimate analyses, porous structure analysis by Brunauer-Emmett-Teller (BET) surface area from nitrogen (N2) adsorption isotherm, ash composition analysis and ash fusion temperature. The effects of temperature and nature of different solid fuels on gasification reactivity have been discussed. Gasification kinetics has been investigated using two nth-order kinetic models, such as homogeneous model (HM) and shrinking core model (SCM). Influence of diffusion resistance on gasification behaviour of different solid fuels is also reported. Thus, the present study will be helpful to realise the effects of high ash in gasification behaviour as well as in designing and modelling of the suitable gasifier and to establish optimum gasification conditions for petcoke, biomass and high ash coal.