With REHAP entering its final phase, there is increasing interest in its impressive results, highlighted now by the publication of two new papers in influential publications Industrial Crops and Products and the Journal of Industrial Ecology. Both are published in Open Access, while the latter received a prestigious gold standard award for data transparency.
Industrial Crops and Products published a paper titled Valorisation of Hydrolysis Lignin Rest from Bioethanol Pilot Plant: Process Development and Upscaling based on the work in the project at Tecnalia, the Bio-Based Europe Pilot Plant (BBEPP) and VTT.
The aim of this work was to find a scalable process to purify lignin and separate the cellulose-rich fraction from a poplar wood hydrolysis rest produced at a bioethanol pilot-plan and the results support the suitability of the solid rest hydrolysate as a fermentation feedstock, allowing an enhanced valorisation of this lignocellulosic residue.
Lead author on the paper was Ingemar Svensson with Tomás Roncal and Aitor Barrio of Tecnalia, Karel de Winter, Anoek Van Canneyt of BBEPP and Tarja Tamminen and Atte Mikkelson of VTT.
More recently, the Journal of Industrial Ecology published another REHAP paper titles Environmental Benefits of Large-Scale Second-Generation Bioethanol Production in the EU: An Integrated Supply Chain Network Optimisation and Life-Cycle Assessment Approach.
The work, conducted by REHAP partners at the University of Augsburg, examined the environmental benefits and economic viability of optimal second-generation bioethanol production network configurations to substitute petrol and/or first-generation bioethanol in the EU using multi-criteria mixed-integer linear programming in a multi-dimensional analysis approach.
The results comprise environmentally optimal decisions for 18 impact and three damage categories, as well as economically optimal solutions for different excise and carbon tax scenarios.
The impact categories global warming potential, particulate matter, and land use are affected the most. Optimal network decisions for different environmental objectives can be clustered into three groups of mutual congruencies, but opportunity costs between the different groups can be very high, indicating conflicting decisions. The decision to substitute petrol or first-generation ethanol has the greatest influence. The results of the multi-dimensional analysis suggest that the damage categories human health and ecosystem quality are suitable to unveil tradeoffs between conflicting environmental impacts, e.g. global warming and land use. Taking human health and ecosystem quality as environmental decision criteria, second-generation bioethanol should be used to concurrently substitute first-generation bioethanol and petrol (100% and 18% of today’s demand in the EU respectively). However, economic optimization shows that with current taxation, bioethanol is hardly competitive with petrol, and that excise tax abatement or carbon taxes are needed to achieve these volumes.
Lead author on the paper was Lars Wietschel along with Lukas Messmann, Andrea Thorenz and Axel Tuma, all of the Institute of Materials Resource management at the University of Augsburg.