Solidification characteristics of green tea as raw material of solid fuel

Abstract

Biocoke (BIC), made from all types of biomass is a solid fuel. Hemicellulose and lignin, essential chemical components of biomass, work as bonding agents of BIC solidification because they have softening and fluidity characteristics. Their characteristics make bonding structure inside of BIC during the formation process. Previous studies suggested that physical and mechanical characteristics of BIC are different if raw materials (kinds of biomass) are different even if forming conditions are the same. It was inferred that the reason was different of content rate of main components. Among various biomass, green tea has excellent formability. In this paper, we focus on the potential of green tea as a raw material of BIC. Firstly, we compared the fluidity of green tea with other biomass. Then, compressive strength tests of BIC made from green tea and other biomass were conducted. We used the trunk of conifers, the bark of conifers, bagasse, and rice straw other than green tea. The result of fluidity test indicated that green tea is easiest-to-flow biomass among the five biomasses. Moreover, the flow starting temperature was able to estimate from a content percentage and moisture content with ±30% accuracy by using our estimated equation. As results of compressive strength test, each BIC which was made from five biomasses have two peak points of compressive strength and apparent density. Green tea BIC made under all the test conditions has high apparent density 1.3-1.4g/cm³. On the other hand, green tea BIC has the lowest compressive strength among the five biomasses tested. We found out that the raw material which it is easy to fluidize by heating has low compressive strength from these results.