This paper presents a techno-economic assessment of three novel routes for the production of bio-based aromatics from lignin. It aims to provide insights into their feasibility and hotspots at an early stage of development to guide further research and development and to facilitate commercialization. The lignin conversion routes are: (non-catalytic) lignin pyrolysis, direct hydrodeoxygenation (HDO), and hydrothermal upgrading (HyThUp). The products generated are mixed oxygenated aromatic monomers (MOAMON), light organics, heavy organics, and char. For the technical assessment, conceptual design followed by process modeling in Aspen Plus was based on experimental yields. The models generated indispensable data on material and energy flows. An economic assessment was then conducted by estimating operating and capital costs. Return on investment (ROI), payback period (PBP), and net present value (NPV) were used as key performance indicators. Downstream processing was especially demanding in the HyThUp process due to the presence of a significant flow rate of water in the system, which significantly increased external utility requirements. Due to complex separations, the HyThUp process showed the highest capital cost (35% more than pyrolysis). Operating costs were the highest for the direct HDO process (34% more than pyrolysis) due to the use of hydrogen. Overall, the direct HDO process showed the highest ROI (12%) and the shortest PBP (5 years) due to high yields of valuable heavy organics (32%) and MOAMON (24%). Direct HDO was found to be feasible with a positive NPV based on prices used in the assessment. Among the three processes investigated, the direct HDO process therefore appeared to be the most promising, and consideration should be given to further development and commercialization of this process.

This study assesses the techno-economic and environmental performance of C6 sugars production from softwood (spruce) and corn. Two technologies were considered in the assessment: organosolv of spruce woodchips (2nd generation) and corn wet milling (1st generation). Process models were developed to generate relevant data to assess the technical performance and derive inputs for the economic and environmental assessments. The economic assessment was carried out using Net Present Value (NPV) as indicator, while the environmental assessment followed a prospective cradle-to-gate life cycle assessment (LCA) for 5 impact categories. The results indicate that when organosolv is integrated with an anaerobic digestion unit, the net energy requirements are lower than those of the wet milling process to produce an equivalent flowrate of C6 sugars. Assuming equivalent C6 sugar prices for the two technologies (300 €/t), the corn based technology shows positive NPV (178 M€) and lowest fixed capital investment requirements (55 M€). The organosolv technology (coupled to anaerobic digestion) also shows positive NPV (238 M€) at base case lignin prices (630 €/t), but higher fixed capital investment needs (236 M€). The economics of the organosolv process were found to be highly sensitive to sugar and lignin yields and prices as well as biomass feedstock costs. From an environmental perspective, the organosolv based routes show relatively better performance than corn wet milling, with 3 categories including climate change and non-renewable energy use showing lower impacts and 2 showing potentially higher impacts. Overall, the organosolv process (2nd generation) shows better performance from an environmental point of view in addition to a positive NPV. However, the inherent risks of new technologies and high investments associated with the 2nd generation technologies assessed in this work, mean that significant additional development, coupled with appropriate government support, are likely necessary before full-scale implementation.

A study on integration of Power-to-Gas technology with bio-methane production from bio-syngas produced by biomass gasification shows that a significant amount of excess electricity can be accommodated in bio-SNG production. By adding hydrogen produced from intermittent renewable sources to a CO₂ methanation section, production capacity of methane can be doubled. The business case for Power-to-Gas for bio-methane has been evaluated using three future cumulative electricity prices curves. Results show that a positive business case exists only for price curves based on large amounts of intermittent electricity installed. The room for investment for the electrolyser will mainly and highly depend on future commodity prices and price curves, and will benefit significantly from a decrease in the cost price of the electrolyser. The projected room for investment available for a PEM electrolyser is lower than for a Solid Oxide Electrolyzer (SOE), because of its lower efficiency and resulting higher operating costs. In the case of large capacity of intermittent electricity, the projected room for investment of an SOE electrolyser is 650 €/kW and for a PEM electrolyser 350 €/kW, which corresponds to the projections of future electrolyser costs.