Cotton Gin Trash Biochar Porosity Enhancement - a Literature Review

To evaluate cotton gin trash as a base material for biochar production from gasification, several parallels can be drawn from other biomass sources and techniques. For activated carbon, a measure of quality is the overall porosity and surface area, which is a direct measure of the absorption capabilities of the product. The quality of the biochar varies in several ways due to the differences in the operating parameters of the gasifier. Cotton gin trash itself is a material that, for the most part, is lignocellulosic and therefore provides the underlying carbon structure necessary to produce biochar with acceptable porosity and surface area.

In other research, bio based activated carbon has been produced in different ways from physical and chemical activation. Overall, the best activation was achieved through chemical activation yielding highly porous products. Chemical activation works in helping to break apart linkages in the material yielding larger and deeper pores thereby increasing the absorptive capabilities of the carbon products produced (Viswanathan, 2009). In our work in gasifying cotton gin trash, gasification causes the biomass to undergo physical activation forming biochar. This physical activation has difficulty producing the same deep porosity as chemical processes of activation due to the inability for the heat treatment to penetrate deeply into the material. Other research has suggested chemical pretreatment can mitigate tar formation in the gasification process and leading to a better quality of biochar (Viswanathan, 2009).