Techno‐economic evaluation of a natural deep eutectic solvent‐based biorefinery: Exploring different design scenarios

Abstract

This paper presents a comprehensive techno‐economic evaluation of an integrated natural deep eutectic solvent (NADES)‐based biorefinery – a 1 ton day−1 capacity design plant. The key parameters include payback period, net present value (NPV), and internal rate of return (IRR). These were compared with the parameters of conventional biorefineries. The ‘nth plant’ results clearly revealed that the single product‐based biorefinery is not a sustainable approach. Hence, value‐added products viz., cellulose, lignin, xylan, silica, etc., play a vital role in the cost‐effectiveness of bio‐based biorefineries. Based on ‘base‐case’ experimental results, a pilot‐scale plant design scenario is most feasible, with a NPV of 1.4 million USD, >100% IRR, and a payback period of <2 years. Sensitivity analysis revealed that lignin has the greatest impact on revenue. This report proves that multi‐product biorefineries provide better sustainability. The concepts of solvent recycling and reuse, and key challenges to the commercialization of this design approach, were also discussed. The application of NADES in biorefineries, has several advantages, making the implementation of NADES a key feature for increased sustainability in this industry. © 2020 Society of Chemical Industry and John Wiley & Sons, Ltd

Green Deep Eutectic Solvents for Microwave-Assisted Biomass Delignification and Valorisation

“…Indeed, Kumar et al demonstrated that, even after vigorous washing of the pretreated biomass with water for removal of the NADES reagent from the biomass residue, a still negligible amount of the NADES reagent was strongly bound to the biomass. Intriguingly, the cellulase activities were found to be increased significantly where the pH of the NADES reagent is close to neutrality, while it decreased in acidic NADES reagents, with a nearly complete loss in enzyme activity after 24-h incubation even in 5% ( v/v ) NADES reagent [ 42 ].…”

“…Several recent reviews highlight the potential use of NADESs for biomass pretreatment, [ 40 , 41 , 42 ]; in particular, Kumar et al (2016) [ 43 ] recently demonstrated how hydrophilic NADESs could replace other harsh chemical agents such as hydrochloric acid and sodium hydroxide for pretreatment of lignocellulosic agriresidues.…”

History repeats itself again: Will the mistakes of the past for ILs be repeated for DESs? From being considered ionic liquids to becoming their alternative: the unbalanced turn of deep eutectic solvents

“…158 Based on this DES, Kumar et al carried out a technical-economic analysis for a biorefinery process that utilises different types of biomass for the production of cellulose, lignin, and silicates in a plant-and economically viable way. 159 Although the inhibition effect of the LA component of DES was easily overcome by optimising one-pot saccharification pretreatment processes, 156 the remaining problems were more difficult to solve. Replacing LA with other organic acids only partially solved the difficulties described above.…”

“…This price can rise significantly in the case of low molecular weight native and/or high-purity lignin, thus showing the economic relevance of the above described 'lignin first' processes. 172 Of the industrial-scale pretreatment processes, Organosolv processes are the mildest towards the structure of lignin and thus the most suitable for the 'lignin-first' biorefinery. 173 Although the limitations of such processes have previously been pointed out both economically and environmentally, lignin obtained by Organosolv processes is nowadays the reference material in the lignin field.…”

“…Of the few papers dealing with techno-economic evaluations of processes involving DESs, three are related to the subject of this analysis. [353][354][355] Specifically, these reports describe the treatment of rice straw and switchgrass either with ChCl : LA or ChCl : EG with 1 wt% of H 2 SO 4 for the production of low molecular weight products. Two major conclusions can be drawn from these studies: (a) the development of multi-product biorefineries should be targeted in view of profitable and sustainable processes instead of a single, high- volume-low-value compound, and (b) the biomass/DES ratio should be as high as possible to reduce the costs of solvents required for the recovery of the biomass fractions from the DES system and for the overall DES recycling.…”