Pyrolysis and Gasification Processes in Coal and Biomass Systems

Pyrolysis and gasification are thermochemical routes for converting carbonaceous materials into useful products under controlled conditions. In pyrolysis, coal or biomass is heated in the absence of oxygen to yield solid char, condensable tars and vapours, and permanent gases. The relative proportions of these products depend on heating rate, peak temperature and feedstock composition. Gasification involves partial oxidation, steam or CO₂ addition to char, producing a synthesis gas rich in carbon monoxide, hydrogen and methane. Process variables such as temperature, pressure, gasifying agent and catalyst presence govern reaction pathways, tar cracking and char reactivity. Advances in reactor design—from fixed beds and fluidised beds to entrained flow systems—have enabled finer control of heat and mass transfer. Integration of pyrolysis and gasification with carbon capture and utilisation or renewable hydrogen production underscores their global significance for energy security, waste valorisation and decarbonisation of industrial processes.

Research from Nature Portfolio

Recent studies have demonstrated that employing carbon dioxide as the heat‐carrying medium in oil shale pyrolysis lowers the activation energy of key devolatilisation stages and increases the release of volatile compounds relative to nitrogen. Thermodynamic analysis reveals that CO₂ atmospheres promote endothermic cracking reactions, yielding higher gas volumes and enhancing the overall conversion efficiency. These findings suggest that CO₂‐assisted pyrolysis can simultaneously sequester carbon dioxide and improve hydrocarbon recovery, pointing towards integrated schemes for cleaner fossil resource utilisation.

Pyrolysis and Gasification Processes in Coal and Biomass Systems publication trend

The graph below shows the total number of articles in pyrolysis and gasification processes in coal and biomass systems across all publications each year (not limited to Nature Index journals).

Technical terms

Pyrolysis: Thermal decomposition of organic material in the absence of oxygen, yielding char, tars and gases.

Gasification: Partial oxidation of carbonaceous feedstock with air, steam or CO₂ to produce syngas (CO and H₂).

Activation energy: Minimum energy required to initiate a chemical reaction or bond breakage during thermal conversion.

Thermogravimetric analysis (TGA): Technique measuring mass change of a sample as it is heated under controlled atmosphere.

Alkali and alkaline earth metallic species (AAEM): Mineral elements (e.g., K, Na, Ca, Mg) that catalyse char reactivity during pyrolysis and gasification.

Torrefaction: Mild thermal pretreatment of biomass (200–300 °C) under inert atmosphere to improve grindability and energy density.

Syngas: Synthesis gas, a mixture of carbon monoxide and hydrogen, often with CO₂ and methane, derived from gasification.

References

1. Kinetics and thermodynamics evaluation of carbon dioxide enhanced oil shale pyrolysis. Scientific Reports (2021).
2. Thermogravimetric analysis and kinetic modeling of the pyrolysis of different biomass types by means of model-fitting, model-free and network modeling approaches. Journal of Thermal Analysis and Calorimetry (2024).
3. Steam Gasification of Sawdust Biochar Influenced by Chemical Speciation of Alkali and Alkaline Earth Metallic Species. Energies (2018).
4. Kinetics and Performance of Raw and Torrefied Biomass in a Continuous Bubbling Fluidized Bed Gasifier. Waste and Biomass Valorization (2017).