Torrefaction Process of Millet and Cane Using Batch Reactor

Abstract

Energy crops and waste coming from agricultural production have the most promising perspective from all kind of renewable energy sources in Poland. Biomass is most often subjected to a compaction process in order to facilitate its energy use. Currently, intensive works on the process of biomass torrefaction are being carried out. In this paper author presents research results which are the optimum parameters of the torrefaction process. The most important information about torrefaction process are temperature and residence time. Both parameters are essential to designing and construction of industrial biomass torrefaction installations. In this investigation, authors examined the torrefaction process of two types of energy crops: cane, millet. Those types of biomass were dictated by the indicators: both biomass grow in low-grade soils and have increase in HHV. In this paper author has chosen thermogravimetric analyses and a setup with a batch reactor. Using thermogravimetric analyzer and installation with special design batch reactor for torrefaction process, cane and millet were investigated to obtain an optimal torrefaction process temperature, residence time and best fuel characteristic. Installation with batch reactor ensured the stability of energy crops torrefaction process and continues conditions. New founding’s about torrefaction process done by the authors were done using two types of analyzes: thermogravimetric and second using experimental setup with batch reactor to find best operation condition for carbonization of energy crops which is 30% of mass loss and the highest caloric value with that loss. Proper torrefaction process temperatures are a temperature in a range of 242–244 °C, and a residence time in a range of 12–13 min. These parameters could be used as a constraint in the design of torrefaction installations and also maintenance.