Machine learning for surrogate process models of bioproduction pathways

Technoeconomic analysis and life-cycle assessment are critical to guiding and prioritizing bench-scale experiments and to evaluating economic and environmental performance of biofuel or biochemical production processes at scale. Traditionally, commercial process simulation tools have been used to develop detailed models for these purposes. However, developing and running such models can be costly and computationally intensive, which limits the degree to which they can be shared and reproduced in the broader research community. This study evaluates the potential of an automated machine learning approach to develop surrogate models based on conventional process simulation models. The analysis focuses on several high-value biofuels and bioproducts for which pathways of production from biomass feedstocks have been well-established. The results demonstrate that surrogate models can be an accurate and effective tool for approximating the cost, mass and energy balance outputs of more complex process simulations at a fraction of the computational expense.

Technoeconomic and life cycle analysis of soluble dietary fiber concentrate production from waste orange peels

This research aims to optimize the environmentally sustainable and economically feasible process for soluble dietary fiber concentrate (SDFC) production from waste citrus peel by different physical methods, including micronization, autoclave, autoclave followed by micronization, extrusion, and ultrasonication. The study is mainly divided into two sections. The first section deals with a detailed life cycle assessment (LCA) of the size 40 kg SDFC/batch process and investigates the influence of various renewable energy sources, including biomass, solar, and wind electricity, on the environmental impact and compares it with mixed grid electricity. It was observed that the use of solar and wind electricity reduces CO₂ emissions by 95.93 % and 99.07 %, respectively. In the second section, technoeconomic analysis (TEA) was performed of all processes for the same capability as LCA, with sensitivity analysis to investigate the influence of batch size by varying batch size from 10 kg to 250 kg to investigate the impact of scale-up from pilot to industrial scale. Moreover, study the impact of energy sources from mixed-grid to renewable energy on total plant economics. TEA shows that extrusion performs the best among all, with an internal rate of return of 43.77 %. Whereas by using solar-based electricity, the overall utility cost is reduced by 58 % compared to the mix grid electricity.

Technoeconomic assessment of an FTTH network investment in the Greek telecommunications market

Recent years have seen an increasing need for higher broadband connections, fueled by novel applications including fifth generation wireless networks (5G). The European Commission is working on achieving specific milestones regarding the development of next generation networks. Many EU countries have opted to adopt a gradual migration path towards the Fiber-to-the-Home (FTTH) technology in view of the high costs of implementation. The Fiber-to-the-Cabinet (FTTC) architecture, combined with very-high-bit-rate digital subscriber line 2 (VDSL2) and vectoring noise cancellation techniques may therefore provide a viable short-term basis solution. Techno-economic modeling and assessment is vital at the initial stages of the development of a telecommunication network investment project involving high capital expenditures for the infrastructure. The present work provides a techno-economic model in order to assess the prospects of such a network upgrade project from a financial perspective, following a three-way migration path. The three stages are: the implementation of the FTTC architecture with VDSL2 vectoring technology, the upgrade to FTTC with G.Fast and finally the migration to FTTH. The analysis is implemented over a suburb of the city of Athens, Greece. Different scenarios are evaluated, predicting profits even from the first years following the investment. The analysis includes the estimation of the degree of market penetration, analytical cost calculations for the implementation and operation of the network and the evaluation of crucial financial indicators, regarding the prospects of the investment in vectoring services. The study can serve as a complete road-map and can be applied in similar upgrade scenarios. The most important outcome of the analysis is that the profits resulted from each upgrade will finance the next step.

A review on strategies to reduce ionic liquid pretreatment costs for biofuel production

Worldwide demand for renewable energy has promoted the considerable exploration of biofuel production from lignocellulosic biomass. Ionic liquid pretreatment is of great interest to render biomass amenable for biofuel production, however, its unaffordable cost stimulates significant attention to the feasibility of commercialization. This review aims to compile the latest advances with respect to reducing production costs for ionic liquids-based biorefineries. Protic ionic liquids offer relatively low synthesis costs, but excessive antisolvent washing of the pretreated biomass is often inevitable. Recovering ionic liquids requires several separation and purification steps, and the reuse of ionic liquids could significantly lose functionality due to the degradation. It is promising to screen ionic liquids-tolerant enzymes and strains for one-pot saccharification and fermentation without solid-liquid separation, however, there is still a need for subsequent recovery of ionic liquids. Additionally, technoeconomic analysis and life cycle assessment are highly recommended to evaluate the economic and environmental impacts.

Recent advances in biogas production using Agro-Industrial Waste: A comprehensive review outlook of Techno-Economic analysis

Agrowaste sources can be utilized to produce biogas by anaerobic digestion reaction. Fossil fuels have damaged the environment, while the biogas rectifies the issues related to the environment and climate change problems. Techno-economic analysis of biogas production is followed by nutrient recycling, reducing the greenhouse gas level, biorefinery purpose, and global warming effect. In addition, biogas production is mediated by different metabolic reactions, the usage of different microorganisms, purification process, upgrading process and removal of CO₂ from the gas mixture techniques. This review focuses on pre-treatment, usage of waste, production methods and application besides summarizing recent advancements in biogas production. Economical, technical, environmental properties and factors affecting biogas production as well as the future perspective of bioenergy are highlighted in the review. Among all agro-industrial wastes, sugarcane straw produced 94% of the biogas. In the future, to overcome all the problems related to biogas production and modify the production process.

An integrated deep eutectic solvent-ionic liquid-metal catalyst system for lignin and 5-hydroxymethylfurfural production from lignocellulosic biomass: Technoeconomic analysis

There is an increasing interest in deep eutectic solvent (DES) and ionic liquid (IL) for lignin and 5-hydroxymethylfurfural (HMF) production from lignocellulosic biomass, but their economic costs raise great concerns. In this study, the effects of DES (ZnCl₂-lactic acid)/IL([EMIM]Cl)/metal catalysts (CuCl₂-CrCl₂) recycling time, acetone/water washing volume, HMF yield, and production capacity on total capital investment, annual operating cost, and net present value (NPV) of the refinery were elucidated. Results showed that annual operating cost was highly associated with DES/IL/metal catalysts recycling time as it determined raw materials cost. The HMF MSP of $16453/MT for the base case (ZnCl₂/lactic acid recycling 5 times, acetone/water washing 5 volumes, CuCl₂-CrCl₂-[EMIM]Cl recycling 10 times, HMF yield of 55%, and production capacity of 100 MT/h) was achieved with an IRR of 10%. Sensitivity analysis identified the unit costs of lactic acid and [EMIM]Cl as the dominant contributors to the HMF MSP.

Catalytic conversion of waste corrugated cardboard into lactic acid using lanthanide triflates

The efficient strategy for waste conversion and resource recovery is of great interest in the sustainable bioeconomy context. This work reports on the catalytic upcycling of waste corrugated cardboard (WCC) into lactic acid using lanthanide triflates catalysts. WCC, a primary contributor to municipal solid wastes, has been viewed as a feedstock for producing a wide range of renewable products. Hydrothermal conversion of WCC was carried out in the presence of several lanthanide triflates. The reaction with erbium(III) triflate (Er(OTf)₃) and ytterbium(III) triflate (Yb(OTf)₃) resulted in high lactic acid yields, 65.5 and 64.3 mol%, respectively. In addition, various monomeric phenols were readily obtained as a co-product stream, opening up opportunities in waste management and resource recovery. Finally, technoeconomic analysis was conducted based on the experimental results, which suggests a significant economic benefit of chemocatalytic upcycling of WCC into lactic acid.

Plant biomass fermentation by the extreme thermophile Caldicellulosiruptor bescii for co-production of green hydrogen and acetone: Technoeconomic analysis

A variety of chemical and biological processes have been proposed for conversion of sustainable low-cost feedstocks into industrial products. Here, a biorefinery concept is formulated, modeled, and analyzed in which a naturally (hemi)cellulolytic and extremely thermophilic bacterium, Caldicellulosiruptor bescii, is metabolically engineered to convert the carbohydrate content of lignocellulosic biomasses (i.e., soybean hulls, transgenic poplar) into green hydrogen and acetone. Experimental validation of C. bescii fermentative performance demonstrated 82% carbohydrate solubilization of soybean hulls and 55% for transgenic poplar. A detailed technical design, including equipment specifications, provides the basis for an economic analysis that establishes metabolic engineering targets. This robust industrial process leveraging metabolically engineered C. bescii yields 206 kg acetone and 25 kg H2 per metric ton of soybean hull, or 174 kg acetone and 21 kg H2 per metric ton transgenic poplar. Beyond this specific case, the model demonstrates industrial feasibility and economic advantages of thermophilic fermentation.

Corinthian currants finishing side-stream: Chemical characterization, volatilome, and valorisation through wine and baker's yeast production-technoeconomic evaluation

The industrial currants finishing generates a considerable amount of side-stream (FSS) with great potential for biotechnological exploitation. The chemical composition of FSS generated from the premium quality Vostitsa currants was studied. Its use for wine making (at low temperatures, using both free and immobilized yeast) combined with baker's yeast production (with minor nutrient supplementation), is also proposed. Analysis showed that FSS has a rich volatilome (including Maillard reaction/lipid degradation products), increased antioxidant capacity, and total lipid and phenolic contents, compared to the marketable product (currants). However, acidity levels and the presence of specific volatiles (such as acetate esters and higher alcohols) may be indicative of microbial spoilage. The wines made from FSS were methanol free and contained higher levels of terpenes (indicating hydrolysis of bound forms) and fermentation-derived volatiles, compared to FSS. A preliminary technoeconomic analysis for integrated wine/baker's yeast industrial production, showed that the investment is realistic and worthwhile.

Development and cost-benefit analysis of a novel process for biofuel production from microalgae using pre-treated high-strength fresh cheese whey wastewater

In this study, a novel two-step integrated process is proposed to facilitate the microalgae biofuel production as well as fresh cheese whey wastewater (FCWW) treatment simultaneously. The pre- and post-treatment of high-strength FCWW were performed by means of coagulation and algal cultivation, respectively. The pre-treatment of FCWW for maximum removal of chemical oxygen demand (COD), turbidity (TUR) and total solids (TS) as responses was obtained by statistical optimization of coagulation parameters. The maximum removal of COD, TUR and TS at the optimum level of variables was obtained as 68.09%, 47.80% and 73.63%, respectively. The pre-treated FCWW was further treated by Chlorella pyrenoidosa and observed a significant reduction in the above-mentioned responses (87-94%). The maximum algal biomass yield and lipid productivity were observed as 2.44 g L^-1 and 77.41 mg L^-1 day^-1, respectively. Based on promising results of FCWW treatment and its use as a third-generation biodiesel feedstock, a cost-benefit analysis of the developed process was assessed for microalgal oil production. The total profit earned by the integrated process model was $9.59 million year^-1. Accordingly, the estimated production cost of algal oil (TAG) from the developed system was estimated to be $79.03 per barrel.

Lignocellulosic ethanol production without enzymes--technoeconomic analysis of ionic liquid pretreatment followed by acidolysis

Deconstruction of polysaccharides into fermentable sugars remains the key challenge in the production of inexpensive lignocellulosic biofuels. Typically, costly enzymatic saccharification of the pretreated biomass is used to depolymerize its cellulosic content into fermentable monomers. In this work, we examined the production of lignocellulosic recovery, a process that does not require the use of enzymes to produce fermentable sugars. In the base case, the minimum ethanol selling price (MESP) was $8.05/gal, but with improved performance of the hydrolysis, extraction, and sugar recovery, the MESP can be lowered to $4.00/gal. Additionally, two scenarios involving lignin recovery were considered. Although the results based on current assumptions indicate that this process is expensive compared to more established technologies, improvements in the hydrolysis yield, the sugar extraction efficiency, and the sugar recovery were shown to result in more competitive processes.