AbstractsBiology & Animal Science

Impact of torrefaction on grindability, hydrophobicity and fuel characteristics of biomass relevant to Hawaiʻi

by Dong Li




Institution: University of Hawaii – Manoa
Department:
Year: 2016
Keywords: Torrefaction; Fuel; Biomass; Pretreatment
Posted: 02/05/2017
Record ID: 2110889
Full text PDF: http://hdl.handle.net/10125/42578


Abstract

M.S. University of Hawaii at Manoa 2015. Torrefaction is a thermal treatment process that can significantly improve fuel properties of solid biomass, provide alternative fuel source for coal fired plants, and contribute to greenhouse gas emission mitigation. This thesis studied the impact of torrefaction on selected tropical biomass: leucaena, energy cane, eucalyptus, sugarcane, sugar cane bagasse and purple banagrass, at torrefaction temperatures of 182, 206, 220, 248 and 273°C. Dewatering/leaching treatment was used on energy cane, sugarcane and purple banagrass. Fuel properties, including heating value, mass, energy yield and ultimate, proximate analysis, were determined. All biomass species generally experienced an increase in mass loss and HHV with rising temperature. Energy yield for woody and dewatered/leached (S3) grass biomass was substantially larger than parent grass species (S0) that were not subjected to dewatering/leaching. Proximate analysis verified that increasing torrefaction temperature resulted in increased fixed carbon content and decreased volatile matter content. A Van Krevelen diagram constructed from ultimate analysis data was presented. The research also explored about the grindability and hydrophobicity characteristics of all samples. Torrefaction improved the grindability and temperatures of 200 to 225 °C are recommended to attain comparable grinding behavior to coal commonly used in Hawaii. Leucaena was the exception, requiring a torrefaction temperature of 260 °C to achieve similar results. Torrefaction generally improved the hydrophobicity characteristics of all samples and hydrophobicity increased with increasing torrefaction temperature. Woody and dewatered/leached grass species were more hydrophobic than grass species that were not dewatered/leached.