Process simulation and assessment of the impact of satellite biorefineries and product diversification on the economic and environmental performance of energy-targeted biorefineries

Energy-targeted biorefineries (ETBs) are in high demand for renewable and clean energy provision. However, ETBs have low economic performances due to the low economic value of energy products (e.g., ethanol, biogas, and electricity) against high feedstock transportation, capital, and operational costs. In addition, the ETBs have low environmental performance associated with feedstock transportation and operational requirements. Operating ETBs as integrated satellite biorefineries (SB) could potentially increase economic and environmental performance by minimizing feedstock transportation and emissions while diversifying into high-value products can increase profitability. Therefore, comparative techno-economic analysis (TEA), and life cycle analysis (LCA) were performed to quantify the economic and environmental benefits of SB and diversification of energy products (DEP) with the inclusion of high-value chemical products (HVCP). Three biorefinery scenarios (S1–S3) were simulated (in Aspen Plus ®) to evaluate the impact of satellites and product diversification. S1 involved producing only energy products i.e., ethanol, biogas, & electricity (EBE) at varying SB capacities (90–4368 kt/y) and centralized biorefinery (CB) at a capacity of 8 736 kt/y. S2 involved the inclusion of lactic acid (LA) in the products in S1. S3 involved the replacement of ethanol in S1 with LA. The economic performance was assessed based on net present values (NPV), annual profits (AP), and minimum product selling price (MPSP). The environmental performance was assessed via fossil resource depletion (FRD), global warming (GW), and terrestrial acidification (TA) impact categories. The SB and DEP demonstrate better economic performance compared to CB. Notably, SB coupled with DEP provides 286, 362, and 57 % improvement in NPV, AP, and FRD, respectively. For example, at the capacity of 1107 kt/y for S1 & S2 and 728 kt/y for S3 the SB increases NPV of CB from -$17280 to -$10754, $3144 to $6669 and $8575 to $13613 for S1–S3, respectively. Additionally, DEP for the SB led to an increase of NPV from -$10754 to $6669 for S1–S2, & $10754 to $13613 for S1–S3, respectively. Furthermore, SB improves the FRD from 299.31 to 127.54, 371.60 to 199.85, and 372 to 200.21 kg oil eq/FU for S1–S3, respectively. Therefore, operating ETBs as SB increases economic and environmental performances by minimizing feedstock transportation and emissions while product diversification increases profitability due to a high-value product mix.