期刊名称：International Journal of Energy and Environment
印刷版ISSN：2076-2895
电子版ISSN：2076-2909
出版年度：2016
卷号：7
期号：2
页码：159-168
出版社：International Energy and Environment Foundation (IEEF)
摘要：In this study torrefaction was demonstrated at a Torrec Ltd. pilot plant located in Mikkeli, eastern Finland. The pilot plant with a nominal capacity of 10,000 tonnes/year began operation in August 2014. The torrefaction solution was a batch type process based on a vertical reactor, where biomass material flows by gravity without drives or actuators and torrefaction happens by steam inertization and accurate process control. Steam was supplied from the local biomass combined heat and power (CHP) plant next to the pilot plant. The product quality of torrefied pellets was analysed by testing alternative local woody biomass sources, such as forest chips made from coniferous trees (spruce, pine) and broadleaf (birch), as well as by-products such as veneer chips. Lower heating value as dry basis varied 18.47–20.53 MJ/kg with a moisture content of 4.41-8.60% for torrefied pellets. All raw materials were suitable for torrefied pellet production without binder addition. Noteworthy was good results also with hardwood species. The potential Finnish customers are CHP plants aiming to replace coal with pellets. In 2013 coal use was 31.2 TWh, where condensing was 15.3 TWh, CHP 14.2 TWh, and separate heat 1.6 TWh in Finland. If half of the current coal use in CHP would be replaced by biocoal, then Finnish potential bio-coal markets would be 7 TWh or 1.2 million tonnes of pellets/year. Aided by the results of this demonstration study and modelling of logistics it is possible to evaluate the competitiveness of torrefied pellets based on the local circumstances .
