Techno-economic analysis of integrated torrefaction and pelleting process

Abstract

ABSTRACT In this work, a techno-economic analysis of an integrated torrefaction and pelleting process is conducted. The proposed integrated process is a single-step process to produce torrefied rice straw pellets. The proposed process shall work as an alternative to the existing multi-step/multi-site process that has multiple disadvantages. Like the conventional process, the proposed process consists of cutting, drying, grinding, torrefaction, and pelleting unit. However, the proposed process doesn’t involve any external binder as the pelleting and torrefaction steps are merged. The binding is achieved by utilizing the lignin present naturally in the biomass and softens during the torrefaction step. The techno-economic assessment estimates that the briquetting process with a production capacity of 30,000 tons briquette/annum could be very profitable and shows a return on investment (ROI) of 30%, payout time of 2.4 years and break-even point of 42% at a selling price of briquette of 73 $/ton.