Gasification of non-woody biomass: a literature review

Non-woody biomass, having a lower lignin content than woody materials, is a common waste material found in agricultural processing plants and fields. Non-woody biomass is often bulky and has a comparatively low energy content. However, non-woody materials sourced from agricultural waste are abundant and cheap. Experimental studies into gasification of non-woody biomass have been conducted by various researchers. This paper reviews feedstock characteristics, pre-treatments, gasification methods, and future directions of this technology. Due to the heterogeneous nature of non-woody biomass, it is critical to apply suitable pre-treatments prior to gasification. Combining non-woody biomass with a small percentage of high grade carbon sourced from biochar or coal into fuel pellets for co-gasification has the potential to improve fuel quality. Synergistic effects of non-woody biomass-coal/charcoal co-gasification can also reduce tar formation and increase the occurrence of mineral based catalytic reactions. Factors influencing these effects are often complex and require further investigation. 15–20% of the energy content of fuel pellets may be needed to power the biomass pre-treatment process. The gasification of pelletised non-woody waste provides an attractive alternative fuel source to achieve agricultural energy self-sufficiency and off-grid operation

A preliminary assessment of cotton gin waste-mixture co-gasification performance

Co-gasification of non-woody biomass with char may induce a more stable gasification process and reduce tar and bed bridging. This paper presents a preliminary assessment of cotton gin waste-char i.e. coal co-gasification using air as the reactant. The influence of char addition in the mix of pellet fuel of cotton gin waste (CGW)-coal and gasification temperature are assessed using a thermodynamic equilibrium model. It is found that fuel compositions can significantly influence the performance and gasification products. Adding the coal can increase the syngas heating value, while increasing the gasification temperatures may lower the syngas heating value. At higher temperatures, the higher the coal ratio in the mix, the higher increment of syngas heating values. The drying and electricity energy need for a typical gin plant with the capacity of 40 bales/hour production is also assessed. The gin utilising CGW only pellet fuel may only be able to fulfil 69% of the energy required from its waste conversion to energy, while utilizing the mix of 20% coal in the pellet fuel can meet all its energy demand