Biomass Availability Based Novel Approach for Lignocellulosic Biorefineries and Biomethane Plants

Design of biorefineries has been often addressed by process flowsheet optimization tools without adequately considering the local biomass availability. In particular, the optimal plant size does not depend simply on the economies of scale, but also on the biomass feedstock availability and the topology of the territory affecting logistics costs. On the other hand, works aiming at the supply chain optimization consider literature data or approximate correlations to estimate biorefinery technical performance, capital and operating expenditure. The analysis of the biomass availability was developed in the framework of the Basilicata region where residual straw appears to be the most abundant product with an overall production of 400 kton/y. The paper also describes the current value chains and provides some potential scenarios for the conversion to biobased products. In particular, two biobased biorefineries were considered: case 1) production of fuel grade ethanol through the sugar platform; case 2) co-digestion of biomass feedstocks to produce biomethane. The analysis indicated that in the Basilicata region the fuel grade ethanol production offers concrete advantages in terms of CO2 reduction. On the other side, mixed feeding of biogas plants produces a biofuel with a higher energy density thanks to the increased plant production, but lower CO2-equivalent savings