Recent development in production of pellet fuels from biomass and polyethylene (PE) wastes

In the context of the energy crisis, biomass energy has been widely used owing to its wide distribution, astonishing storage capacity, and carbon neutrality. Pelletization is an advanced biomass utilization technology that overcomes the shortcomings of unfavorable transportation and low energy density. How to improve the performance of biomass pellet fuel is of great significance when confronting the situation that various biomass utilization methods are developed rapidly. In many studies, the addition of binders has been used as an effective way to improve the performance of biomass pellet fuels, such as durability, and to mitigate energy consumption by reducing the molding temperature. This paper reviews the forming mechanism of biomass feedstocks and then provides principles for selecting binders, such as high fixed carbon content, low ash, and a high caloric value for the adhesive itself. In addition, the process as well as the mechanism of the pellet fuels production was summarized and highlighted the potential of waste LDPE as a binder.