Integration of bioethanol as an in-process material in biorefineries using mass pinch analysis

9 A biorefinery involving internal stream reuse and recycling (including products 10 and co-products) should result in better biomass resource utilisation, leading to a system 11 with increased efficiency, flexibility, profitability and sustainability. To benefit from 12 those advantages, process integration methodologies need to be applied to understand, 13 analyse and design highly integrated biorefineries. A bioethanol integration approach 14 based on mass pinch analysis is presented in this work for the analysis and design of 15 product exchange networks formed in biorefinery pathways featuring a set of processing 16 units (sources and demands) producing or utilising bioethanol. The method is useful to 17 identify system debottleneck opportunities and alternatives for bioethanol network 18 integration that improve utilisation efficiency in biorefineries with added value co19 products. This is demonstrated by a case study using a biorefinery producing bioethanol 20 from wheat with arabinoxylan (AX) co-production using bioethanol for AX 21 precipitation. The final integrated bioethanol network design allowed the reduction of 22 bioethanol product utilisation by 94%, avoiding significant revenue losses. 23