Effect of torrefaction temperature on energy properties of spent coffee ground Natthanant Bangkha, Wanphut Saechua, Tharathip Nuamyakul and Jiraporn Sripinyowanich Jongyingcharoen E3S Web Conf., 187 (2020) 03009 Published online: 08 September 2020 DOI: 10.1051/e3sconf/202018703009