Efficient removal of tar employing dolomite catalyst in gasification: Challenges and opportunities

Thermochemical Conversion of Animal-Derived Waste: A Mini-Review with a Focus on Chicken Bone Waste

“…Generally, in the gasification process, using a catalyst reduces tar formation, increases the formation of gaseous products [117], and improves overall process efficiency. The catalysts used in the steam gasification of organic waste for increasing H 2 production were the natural catalysts dolomite (CaMg(CO 3 ) 2 ) and olivine ((Mg, Fe) 2 SiO 4 ) [118,119]; alkali and alkaline catalysts and alkaline earth metal salts (sodium additives: NaCl, NaOH, Na 2 CO 3 , and Na 2 SiO 3 ); potassium additives (K 2 CO 3 , KOH, K 2 CO 3 , CH 3 COOK, and KCl); calcium additives (CaCl 2 , CaCl 2 , Ca(OH) 2 , (Ca(NO 3 ) 2 ), and (CaHPO 4 )), magnesium salts, namely, MgCl 2 [120,121]; transition metals (Ni, Pt, Ru, Rh etc. ); and carbon-based materials (activated carbon and char) [122,123].…”

A review of the thermochemistries of biomass gasification and utilisation of gas products

“…143 During air gasification of rice husk, increase in dolomite quantity from 10 to 40%, increased hydrogen, carbon oxide, and carbon dioxide yields from 2.6 to ∼4%, 15.2 to 17.3%, and 9.3 to 10.5%, respectively. 185 The hydrogen content from gasification of cotton stalk chops using dolomite, olivine, and quartz sand was reported as 31.45, 23.72, and 22.79%, respectively, 186 showing the superior performance of dolomite. Furthermore, hydrogen yields from gasification of cellulose, 144 spruce wood pellets, 187 pine saw dust, 188 almond shell, 145 bark pellets, 150 and refuse-derived fuel (RDF), 189 using calcined dolomite were reported to be 8.33, 22.80, 49.33, 55.5, 25.8, and 13%, respectively.…”

“…Olivine ((MgFe) 2 SiO 4 ) is another well-known abundant naturally occurring mineral being used as a catalyst during biomass gasification. 145,150,186,189 As an in-bed additive, the advantages of olivine over silica sand and dolomite are their durability, tar elimination activity, and strong abrasion (anti-wear) resistance during biomass gasification. 150,189 Reduction in tar content (∼42%) was reported with an increase in olivine quantity from 10 to 40%.…”

“…Using naphthalene vapour (gas phase) as a tar model compound, 186 its conversion reactions could be presented as the idealised eqn (17)–(20) as follows:Cracking: C 10 H 8 → 3C 2 H 2 + 4C + H 2 , Δ H 298K = +531 kJ mol −1 Steam reforming I: C 10 H 8 + 10H 2 O → 10CO + 14H 2 , Δ H 298K = +1163 kJ mol −1 Steam reforming II: C 2 H 2 + 2H 2 O → 2CO + 3H 2 , Δ H 298K = +35.6 kJ mol −1 Dry reforming I: C 10 H 8 + 10CO 2 → 20CO + 4H 2 , Δ H 298K = +1575 kJ mol −1 Dry reforming II: C 2 H 2 + 2CO 2 → 4CO + H 2 , Δ H 298K = +118 kJ mol −1 Carbonisation: C 10 H 8 → 10C + 4H 2 , Δ H 298K = −150 kJ mol −1 …”