Extracting the energy-potential values of dolochar via an integrated steam co-gasification route with petcoke and biomass waste

Abstract

Valorization of solid waste substrates has become an essential part of society’s effort to achieve sustainability and carbon neutrality. Consequently, gasification has become a widely adopted methodology to process conventional and renewable carbonaceous feedstock into gas and liquid products in conjunction with the underutilized and prevalent waste resources. Therefore, in the current investigation, a comprehensive set of steam gasification experiments is performed for three genetically different solid waste materials, i. dolochar – an iron ore industry waste, ii. coconut waste – biomass material, and iii. petcoke – refinery waste, in a bench-scale fluidized-bed gasifier. During the detailed investigation, dolochar showed gasification reactivity and the feasibility of utilizing its carbon value to form valuable gaseous products in the form of syngas. Moreover, there was an increase in the energy value of the dolochar product gas when it was gasified with biomass and petcoke samples under identical conditions. Specifically, the carbon conversion and cold gas efficiencies significantly improved from 31.2% to 57.6% and 47.1% to 88.5% when mixed with the coconut-based biomass waste sample, with the highest H₂ content achieving 32.7% in N₂-mix. However, there was a major change in CO₂ concentration when DC was co-gasified with PC, showing an increase in concentration from 10.4% to 18.8%; CH₄ and CO contents in the mix-N₂ were also highest in this case at 8.8% and 15.2%, respectively. Furthermore, various analytical methods were applied to decipher the change in the physicochemical properties.