Co-pyrolysis and co-gasification of coal and biomass in bench-scale fixed-bed and fluidised bed reactors

A Review of Thermal Co-Conversion of Coal and Biomass/Waste

“…No synergy was found. Collot et al [37] also did not find synergy in the co-pyrolysis of Daw Mill coal (bituminous) and Silver Birch Wood in a fluidized bed reactor. In a fixed bed reactor the degree of synergy was insignificant at 1123 K and 1273 K with a heating rate of 10 K/min, using helium as the carrier gas under pressure from 1 bar to 25 bar.…”

“…The presence of dolomite in the fluidized bed has the advantage of decreasing tar content and augmenting gas yield [35]. No evidence of synergetic effect however was found by Collot et al [37] with Polish coal and forest residue mixture. Aznar et al [32] and Andre et al [35] also identified an increase in tar yield with an increase in biomass content of the feedstock, suggesting that synergetic effect during coal and biomass co-gasification might be highly dependent on biomass type as well as gasification conditions.…”

“…Many co-conversion studies related to co-gasification studies have focused on parametric studies of the gasifier [31][32][33][34][35][37][38][39][40][41][42][43], mostly omitting the mechanisms by which mixtures of coal and biomass interact and how coal and biomass thermally degrade. The interaction between coal and biomass during thermal co-conversion is an issue yet to be solved; some devolatilization and pyrolysis results of coal and biomass blends have revealed no or very little synergy between the two fuels [44][45][46][47][48][49][50][51][52][53][54][55][56] while others have revealed significant synergy [43,[57][58][59][60][61][62][63][64][65][66][67][68][69][70][71].…”

“…The char collected was subjected to a CO 2 reactivity test; results from the co-pyrolysis chars were about twice as high as those of coal char alone, and even higher than those of biomass alone while the latter [43] found synergies in a drop-tube reactor. Collot et al [37] concluded in their pyrolysis experiments that neither intimate contact between fuel particles nor their relative segregation led to synergistic effects, making the case of fuels' interaction condition for synergy even more puzzling.…”

Evaluation of Biomass and Coal Co-Gasification of Brazilian Feedstock Using a Chemical Equilibrium Model

“…Some authors (Sjöström et al, 1999;Hernández et al, 2010;Xu et al, 2011;Song et al, 2013) have observed synergies using some combinations of these fuels. However, other authors (Collot et al, 1999;Zhu et al, 2008) reported the lack of interactions among fuels. Zhou (2014) presented a review of synergy effects during co-gasification in several experimental studies.…”