The aim of this study was to evaluate various methods for producing high-quality fuel pellets using rape stalk (RS), which is an agricultural waste. RS was used as a raw material for pellets production after three treatments [distilled water (DW), sulfuric acid (AC), sodium hydroxide (AK) solutions]. Then, fabricated pellets with two binder additions [ rapeseed flour (RF), coffee waste (CW)] were examined to evaluate their fuel qualities. Results showed that binder additions (RF, CW) improve the durability and higher heating value for RS-based pellets. The addition of CW greatly decreased ash content for fabricated pellets. Also, all immersion treatments improved all fuel qualities compared to non-immersed treatment. Particularly, DW-immersion had favorable influences on the increases of higher heating value and durability. Two immersion treatments (AC, AK solution) positively influenced the improvements of bulk density and ash content for fabricated pellets. However, they were required to rinse the residue existed on the RS, and consequently the use of DW-immersion might be the most beneficial way to improve the qualities of RS-based pellets. All qualities of the pellets were acceptable for the European agropellet standards (A- or B-grade). Hence, RS can be used as a raw material for the production of agropellets while outdoor exposure of RS or mixing RS with CW or wood sawdust might be help to better agropellets qualities.

Chemical composition and enzymatic saccharification characteristics of hemp woody core were investigated by their chemical composition analysis and enzymatic saccharification with commercially available cellulases (Celluclast 1.5L and Novozym 342). Hemp woody core have higher xylan and lower lignin contents than its bast fiber. Based on hemicelluloses and lignin composition, hemp woody core is similar with hardwood biomass. However, cellulose was more easily converted to glucose than xylan to xylose and this trend was confirmed both hemp woody core and yellow poplar. Hemp woody core biomass shows higher saccharification than yellow poplar (hardwood biomass) based on cellulose and xylan hydrolysis. With easier enzymatic saccharification in cellulose and xylan, and similar chemical composition, hemp woody core have better biorefinery feedstock characteristics than hardwood biomass.