Comparison of recovery of volatile fatty acids and mixed ketones as alternative downstream processes for acetogenisis fermentation

Abstract

Carboxylates produced by the acetogenisis fermentation of pre‐treated lignocelluloses are precursors to bio‐based products that are alternatives to second‐generation biofuels for biomass valorization. This paper compares the techno‐economic indicators for recovering either mixed ketones or mixed volatile fatty acid (VFA) products from the carboxylates in a fermentation broth through process simulation and financial modeling. This study considers scenarios for (i) an efficient process for ketone production (K‐P) involving dehydration, thermal conversion, and condensation already established in the literature; (ii) VFA production (VFA‐P) with conventional methods of carboxylate acidification and separation; and (iii) advanced VFA acidification and separation methods. In conventional acidification, using mineral acids and calcium alkalis results in wastes; while in advanced acidification, the acids and bases are regenerated. Conventional separation relies on ethyl‐acetate extraction, while advanced separation relies on amine extraction. Scenarios are compared in terms of energy and chemical use, and the internal rates of return (IRR) determined with price ranges assumed for mixed VFAs and mixed ketones. Thus, with optimistic product prices, K‐P and VFA‐P with conventional acidification‐separation have indentical IRRs at 35%, but K‐P is favorable due to the chemical‐intensiveness and waste generation of the VFA‐P. Using advanced acidification and separation could possibly improve the IRR of VFA‐P to 39%, with a capital investment of 2% above that of K‐P, which was estimated at US$ 293 million. Otherwise, a previously patented scheme that integrated acidification and separation based on amine complexation could also produce a VFA process that is environmentally and economically feasible. © 2018 Society of Chemical Industry and John Wiley & Sons, Ltd

Eco-efficient recovery of bio-based volatile C2–6 fatty acids

“…The utility cost of separation and purification accounts 60% [27] to 80% [6] of whole production cost of acids. Considering mixed acid price of $2.70/kg [54] and solvent loss equivalent to 3% of product amount, the utility cost is low enough to apply the proposed scheme to up-scaling processes.…”

Techno‐economic analysis of the valorization of brewers spent grains: production of xylitol and xylo‐oligosaccharides

“…An economic sensitivity analysis is used to identify the important parameters on viability and profitability of the various scenarios. (Assessment, Selected and Gorgens, 2016;Petersen, Franco and Görgens, 2018) b (Gerbrandt, 2014;Biddy et al, 2016) c (Llzo and Lx, no date) d Considered improved or similar feed value as BSG (Tucker et al, 2004) e Based on protein content using $1/kg protein f Price of molasses g Based on protein content wet basis h (Michael O'Donohue, 2014;Clauser et al, 2015) Results…”

“…All authors provided input to the manuscript and read and approved the final manuscript. Hong et al, 2014;Clauser et al, 2015;Petersen, Franco and Görgens, 2018) c Averages from reported literature Hong et al, 2014;Clauser et al, 2015;Petersen, Franco and Görgens, 2018) d e (Wooley, 1997;Wan, Xie and Nancy Ho, 2003) f (Wan, Xie and Nancy Ho, 2003) 6.2.3.2 Discounted cash flow Calculation of total cost of production (TCP) for a product such as xylitol will give an estimate of breakeven cost for xylitol. If market prices for xylitol are lower than TCP and there are no other revenues from production the biorefinery concept will be unprofitable.…”

Evaluation of optimal fermentation conditions for volatile fatty acids production from artisanal fish waste

“…The xed capital investment (FCI) was assumed 1500 USD/Kg FW and it was based in Colombian prices estimates. The economic assumptions used included: 1) the plant life was 20 years, 2) the annual labour and operational costs were assumed to be 25% and 21% of the FCI (Petersen et al 2018). 3) the FCI for scaling up the VFA biore nery plant was de ned by Equation 1.…”