Development of a novel rotary kiln-type reactor for intensified gas-solid reactions: Performance evaluation for solid fuels processing

Abstract

Rotary kiln-type reactors have been investigated at bench, pilot and demonstration scale for a broad range of processes involving solids thermal conversion and gas-solid chemical reactions, such as (among others) lignite drying and lignite/biomass pyrolysis and gasification by means of either indirect heating (gas or electricity), or direct heating through a chemical looping energy carrier. This work focuses on the evolutionary development of a novel reactor of rotary kiln-type for intensified gas-solid reactions. Design and performance highlights are reported, while relevant processes serve herein as benchmarks for reactor evaluation. In the context of the latter class of processes, which constitute an example of a promising energy technology, we evaluated a pair of advanced rotary kiln-type reactors, that is, a gasifier to produce synthesis gas rich in H₂ and a calciner for the regeneration of the solid energy carrier (CaCO₃) and the production of clean CO₂ for chemical exploitation. The novel reactors feature intensified mass and heat transfer rates enabling in this example up to 80 % LHV gasification efficiency and 96 % overall energy efficiency at 0.36 kg/h/L_R solids throughput and 10–12 MJ_syngasLHV/Nm³ fuel gas energy density with up to 80 % v/v H₂ content when operating in Calcium-chemical looping gasification mode.