A Case Study about Biomass Torrefaction on an Industrial Scale: Solutions to Problems Related to Self-Heating, Difficulties in Pelletizing, and Excessive Wear of Production Equipment

The search for different forms of biomass that can be used as an alternative to those more traditional ones has faced numerous difficulties, namely those related to disadvantages that the majority of residual forms present. However, these residual forms of biomass also have advantages, namely the fact that, by being outside the usual biomass supply chains for energy, they are usually much cheaper, and therefore contribute to a significant reduction in production costs. To improve the less-favorable properties of these biomasses, thermochemical conversion technologies, namely torrefaction, are presented as a way to improve the combustibility of these materials. However, it is a technology that has not yet demonstrated its full potential, mainly due to difficulties in the process of scale-up and process control. In this article it is intended to present the experience obtained over 5 years in the operation of a biomass torrefaction plant with an industrial pilot scale, where all the difficulties encountered and how they were corrected are presented, until it became a fully operational plant. This article, in which a real case study is analyzed, presents in a descriptive way all the work done during the time from when the plant started up and during the commissioning period until the state of continuous operation had been reached.