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[Display omitted] • A novel framework to design sustainable biorefineries was applied through simulation. • The distribution of feedstock in the biorefinery processes impacts profitability. • The baker's yeast vinasse has a high potential as a feedstock in circular processes. The present work deals with the biotechnological valorization of the vinasse through a sustainable biorefinery. The aim was to design and analyze, through process simulation, a biorefinery for the valorization of vinasse in products such as organo-mineral fertilizers, supplements for animal feed, and biogas. For this purpose, the SuperPro Designer software was used, and a modified hierarchical decomposition method was applied. One base case and three scenarios were techno-economically assessed, and the net present value was used as a selection criterion. The technological configuration with the best techno-economic criterion was analyzed socially and environmentally. The results suggest that the best configuration of the biorefinery corresponded to scenario 3, with a net present value of USD$73,364,000, a number of direct employees of 38, and a blue water footprint of 16.16 m3/h. These findings highlight the potential of the design of biorefineries to address the valorization of vinasses in Colombia and worldwide. [ABSTRACT FROM AUTHOR]

[Display omitted] • Process design for γ-valerolactone (GVL) production from biomass-derived fructose. • The most profitable scenarios occur when energy from biomass is produced and used. • The Minimum Selling Price (MSP) of GVL obtained was 1.90 €/kg. • The price of raw materials is the most important variable to the Net Present Value. • 10 kt/y production size resulted in the lowest MSP and highest end-of-life revenue. This work proposes a process design and techno-economic assessment for the production of γ-valerolactone from lignocellulosic derived fructose at industrial scale, with the aim of exploring its feasibility, identifying potential obstacles, and suggesting improvements in the context of France. First, the conceptual process design is developed, the process modelled and optimized. Second, different potential scenarios for the energy supply to the process are analyzed by means of a set of economic key performance indicators, aimed at highlighting the best potential profitability scenario for the sustainable exploitation of waste biomass in the context analyzed. The lowest Minimum Selling Price for GVL is obtained at 10 kt/y plant fueled by biomass, i.e. 1.89 €/kg, along with the highest end-of-live revenue, i.e. 113 M€. Finally, a sensitivity and uncertainties analysis, based on Monte Carlo simulations, are carried out on the results in order to test their robustness with respect to key input parameters. [ABSTRACT FROM AUTHOR]

[Display omitted] • Construction and evaluation of novel wood-based ethanol biorefinery systems. • Maximum energy conversion rate of 39% can be achieved with integrated technologies. • Coupling scenarios exhibit less greenhouse gas emissions and improved economics. • Competitive minimum ethanol selling price is promising with higher-levels technology. Poplar is widely used in the paper industry and accompanied by abundant branches waste, which is potential feedstock for bioethanol production. Acid-chlorite pretreatment can selectively remove lignin, thereby significantly increasing enzymatic efficiency. Moreover, lignin residues valorization via gasification-syngas fermentation can achieve higher fuel yield. Herein, environmental and economic aspects were conducted to assess technological routes, which guides further process optimization. Life cycle assessment results show that wood-based biorefineries especially coupling scenarios have significant advantages in reducing global warming potential in contrast to fossil-based automotive fuels. Normalization results indicate that acidification potential surpasses other indicators as the primary impact category. In terms of economic feasibility, coupling scenarios present better investment prospects. Bioethanol yield is the most critical factor affecting market competitiveness. Minimum ethanol selling price below ethanol international market price is promising with higher-levels technology. Further work should be focused on technological breakthrough, consumable reduction or replacement. [ABSTRACT FROM AUTHOR]

Food waste represents a potential source to produce value-added materials replacing the use of virgin ones. However, the use of food waste as feedstock in biorefineries is still at an early stage of development and studies assessing its economic viability at large scale are lacking in the literature. This paper presents a techno-economic and profitability analysis of four food waste biorefineries that use wastes from tomato, potato, orange, and olive processing as feedstock. The study includes the assessment of potentially available quantities of those waste flows in Europe. Due to the low technology readiness level of this kind of biorefineries, a screening methodology to estimate the investment and manufacturing costs as well as two profitability ratios (the return on investment and the payback time) was adopted. Results show that not all the waste feedstocks have the same potential. The most profitable options are those related to implementing fewer plants, namely concentrating the production and capitalising on economies of scale while being at risk of increasing externalities, e.g. due to logistics of the feedstocks. [ABSTRACT FROM AUTHOR]

[Display omitted] • Pretreatment is a key step for biomass conversion. • Deep Eutectic Solvents have shown compare favorably with other pretreatment methods. • Biorefinery approach based on DES pretreated materials is reviewed. • Tecno-economic and environmental issues dealing with DES application are considered. • Updated state-of-the-art and barriers to improvement are discussed in this review. Pretreatment processes — recognized as critical steps for efficient biomass refining — have received much attention over the last two decades. In this context, deep eutectic solvents (DES) have emerged as a novel alternative to conventional solvents representing a step forward in achieving more sustainable processes with both environmental and economic benefits. This paper presents an updated review of the state-of-the-art of DES-based applications in biorefinery schemes. Besides describing the fundamentals of DES composition, synthesis, and recycling, this study presents a comprehensive review of existing techno-economic and life cycle assessment studies. Challenges, barriers, and perspectives for the scale-up of DES-based processes are also discussed. [ABSTRACT FROM AUTHOR]

[Display omitted] • The selection of waste stream for synthesis of biopolymer is an important task. • Recycling of waste stream for biopolymer production reduces several ecological risks. • Processing of green plastic from different waste stream is possible. • Environmental sustainability and its impact on biopolymer production is reviewed. • The emission of greenhouse gas and non-renewable energy use is index of lifecycle assessment. Polyhydroxyalkanoates (PHA) are the more attractive sustainable green plastic, and it has the potential to replace petroleum-based plastics (PBP) in the global market. Recently, most of the developed and developing countries have banned the use of traditional PBP. This increases the demand for green plastic production and positively impacts the global market. Producing green plastic from various waste streams such as whey, animal, and crude glycerol will be eco-friendly and cost-effective. However, the factors influencing the environmental sustainability of PHA production from different waste streams are still unclear. This review could be reinforced concrete to researchers to gather deep knowledge on techno-economic analysis, life-cycle assessment, environmental and ecological risks caused during PHA production from different waste streams. [ABSTRACT FROM AUTHOR]

[Display omitted] • Bioprocess optimization increased in ∼ 2-fold protein productivity (0.39 g.L-1.h−1). • The scaling up in a 65-L bioreactor resulted in 54 g.L-1 protein in 7 days. • The enzyme cocktail showed similar saccharification efficiency to Cellic® CTec2. • The cost of the enzyme produced at pilot scale was estimated in 3.2 USD.Kg−1. • Life-cycle assessment indicates an environmental impact of 6.4 kg CO 2 eq.kg−1. Despite decades of research and industrial applications of Trichoderma reesei , the development of industrially relevant strains for enzyme production including a low-cost and scalable bioprocess remains elusive. Herein, bioprocess optimization, pilot plant scale-up, techno-economic analysis and life-cycle assessment for enzyme production by an engineered T. reesei strain are reported. The developed bioprocess increased in ∼ 2-fold protein productivity (0.39 g.L-1.h−1) and 1.6-fold FPase activity (196 FPU.L-1.h−1), reducing the fermentation in 4 days. Cultivation in a 65-L pilot plant bioreactor resulted in 54 g.L-1 protein in 7 days, highlighting the robustness and scalability of this bioprocess. Techno-economic analysis indicates an enzyme cost of ∼ 3.2 USD.kg−1, which is below to the target proposed (4.24 USD.kg−1) in the NREL/TP-5100–47764 report, while life-cycle assessment shows a carbon footprint reduction of approximately 50% compared to a typical commercial enzyme. This study provides the fundamental knowledge for the design of economically competitive Trichoderma technologies for industrial use. [ABSTRACT FROM AUTHOR]

The economic feasibility and environmental impact is investigated for the conversion of agricultural waste, delactosed whey permeate, through yeast fermentation to a renewable diesel via hydrothermal liquefaction. Process feasibility was demonstrated at laboratory-scale with data leveraged to validate systems models used to perform industrial-scale economic and environmental impact analyses. Results show a minimum fuel selling price of $4.78 per gallon of renewable diesel, a net energy ratio of 0.81, and greenhouse gas emissions of 30.0 g-CO 2 -eq MJ −1 . High production costs and greenhouse gas emissions can be attributed to operational temperatures and durations of both fermentation and hydrothermal liquefaction. However, high lipid yields of the yeast counter these operational demands, resulting in a favorable net energy ratio. Results are presented on the optimization of the process based on economy of scale and a sensitivity analysis highlights improvements in conversion efficiency, yeast biomass productivity and hydrotreating efficiency can dramatically improve commercial feasibility. [ABSTRACT FROM AUTHOR]

This work presents a techno-economic and environmental assessment for a biorefinery based on sugarcane bagasse (SCB), and coffee cut-stems (CCS). Five scenarios were evaluated at different levels, conversion pathways, feedstock distribution, and technologies to produce ethanol, octane, nonane, furfural, and hydroxymethylfurfural (HMF). These scenarios were compared between each other according to raw material, economic, and environmental characteristics. A single objective function combining the Net Present Value and the Potential Environmental Impact was used through the Analytic Hierarchy Process approach to understand and select the best configurations for SCB and CCS cases. The results showed that the configuration with the best economic and environmental performance for SCB and CCS is the one that considers ethanol, furfural, and octane production (scenario 1). The global economic margin was 62.3% and 61.6% for SCB and CCS respectively. The results have shown the potential of these types of biomass to produce fuels and platform products. [ABSTRACT FROM AUTHOR]

Microalgae biofuel production has been extensively evaluated through resource, economic and life cycle assessments. Resource assessments consistently identify land as non-limiting and highlight the need to consider siting based on combined geographical constraints of land and other critical resources such as water and carbon dioxide. Economic assessments report a selling cost of fuel that ranges between $1.64 and over $30 gal −1 consistent with large variability reported in the life cycle literature, −75 to 534 g CO 2-eq MJ −1 . Large drivers behind such variability stem from differences in productivity assumptions, pathway technologies, and system boundaries. Productivity represents foundational units in these assessments with current assumed yields in various assessments varying by a factor of 60. A review of the literature in these areas highlights the need for harmonized assessments such that direct comparisons of alternative processing technologies can be made on the metrics of resource requirements, economic feasibility, and environmental impact. [ABSTRACT FROM AUTHOR]

Highlights: [•] We assessed the economic viability of algal biodiesel under current uncertainties. [•] A global sensitivity analysis was performed using a HDMR technique. [•] Biodiesel production cost for large plants is likely to be £0.8–1.6 per kg. [•] The algae oil content has the greatest effect on the biodiesel production cost. [•] Annual productivity, and future oil and carbon prices are relatively important. [ABSTRACT FROM AUTHOR]

Abstract: The techno-economic characteristics of macro-algae utilisation from European temperate zones was evaluated in a selected Anaerobic Digester (AD) using the chemical process modelling software ECLIPSE. The assessment covered the mass and energy balance of the entire process followed by the economic feasibility study, which included the total cost estimation, net present value calculation, and sensitivity analysis. The selected plant size corresponded to a community based AD of 1.6MWth with a macro-algae feed rate of 8.64tonnes per day (dry basis). The produced biogas was utilised in a combined heat and power plant generating 237kWenet electricity and 367kWth heat. The breakeven electricity-selling price in this study was estimated at around €120/MWh. On the ground of different national and regional policies, this study did not account for any government incentives. However, different support mechanisms such as Feed-in-Tariffs or Renewable Obligation Certificates can significantly improve the project viability. [Copyright &y& Elsevier]

Abstract: Large amount of hydrogen is consumed during the upgrading of bitumen into synthetic crude oil (SCO), and this hydrogen is exclusively produced from natural gas in Western Canada. Because of large amount of emission from natural gas, alternative sources for hydrogen fuel especially renewable feedstocks could significantly reduce CO2 emissions. In this study, biomass is converted to bio-oil by fast pyrolysis. This bio-oil is steam reformed near bitumen upgrading plant for producing hydrogen fuel. A techno-economic model is developed to estimate the cost of hydrogen from biomass through the pathway of fast pyrolysis. Three different feedstocks including whole-tree biomass, forest residues (i.e. limbs, branches, and tops of tree produced during logging operations), and straw (mostly from wheat and barley crops) are considered for biohydrogen production. Delivered cost of biohydrogen from whole-tree-based biomass ($2.40/kg of H2) is lower than that of forest residues ($3.00/kg of H2) and agricultural residues ($4.55/kg of H2) at a plant capacity of 2000dry tonnes/day. In this study, bio-oil is produced in the field/forest and transported to a distance of 500km from the centralized remote bio-oil production plant to bitumen upgrading plant. Feedstock delivery cost and capital cost are the largest cost contributors to the bio-oil production cost, while more than 50% of the cost of biohydrogen production is contributed by bio-oil production and transportation. Carbon credits of $133, $214, and $356/tonne of CO2 equivalent could make whole-tree, forest residues, and straw-based biohydrogen production competitive with natural gas-based H2 for a natural gas price of $5/GJ, respectively. [Copyright &y& Elsevier]

Abstract: Bio-oil, produced by fast pyrolysis of biomass, has high energy density compared to ‘as received’ biomass. The study assesses and compares the cost of transportation ($/liter of bio-oil) of bio-oil by pipeline and truck. The fixed and variable cost components of transportation of bio-oil at a pipeline capacity of 560m3/day and to a distance of 100km are 0.0423$/m3 and 0.1201$/m3/km, respectively. Pipeline transportation of bio-oil costs less than transportation by liquid tank truck (load capacity 30m3) and super B-train trailer (load capacity 60m3) above pipeline capacities of 1000 and 1700m3/day, respectively. When transportation distance is greater than 100km, bio-oil must be heated at booster stations. When transporting bio-oil by pipeline to a distance of 400km, minimum pipeline capacities of 1150 and 2000m3/day are required to compete economically with liquid tank trucks and super B-train tank trailers, respectively. [Copyright &y& Elsevier]

[Display omitted] • Advanced pretreatment techniques focused on destruction of lignocellulosic biomass. • Recent genetic engineering approach in lignocellulose to bioproducts conversion. • Alternative biofuels synthesized from the lignocellulosic biomass was rationalized. • Explored high value bioproducts and biochemicals from lignocellulosic biomass. • Current techno-economic assessment considered for efficient biomass valorization. Lignocellulosic biomass is a highly renewable, economical, and carbon–neutral feedstock containing sugar-rich moieties that can be processed to produce second-generation biofuels and bio-sourced compounds. However, due to their heterogeneous multi-scale structure, the lignocellulosic materials have major limitations to valorization and exhibit recalcitrance to saccharification or hydrolysis by enzymes. In this context, this review focuses on the latest methods available and state-of-the-art technologies in the pretreatment of lignocellulosic biomass, which aids the disintegration of the complex materials into monomeric units. In addition, this review deals with the genetic engineering techniques to develop advanced strategies for fermentation processes or microbial cell factories to generate desired products in native or modified hosts. Further, it also intends to bridge the gap in developing various economically feasible lignocellulosic products and chemicals using biorefining technologies. [ABSTRACT FROM AUTHOR]

[Display omitted] • Design of a continuous process for the valorization of Sargassum muticum seaweed. • Proposal of an alternative process without anaerobic digestion of biomass. • Cash flow analysis to evaluate minimum selling price of fucoidan extract product. • CAPEX estimates were 1.6 to 12.7% lower in the alternative project. • Main product minimum selling price reduced up to 55.3% in the alternative project. This work assesses scale effects in designing a biorefinery from Sargassum muticum seaweed by applying a detailed process modeling methodology. Two process conversion units were simulated: one considering anaerobic digestion steps for producing biogas and generating electricity (base project), and the other with residual seaweed solids sold as fertilizer (alternative project). A comprehensive economic analysis was performed to estimate the minimum selling price of the process's main product (fucoidan extract). Results indicated that capital expenditures are up to 12.7% times higher in the base project. Minimum selling prices of the fucoidan extract product demonstrate the biorefinery's economies of scale for both projects. Seaweed's low methane potential reduces the economic attractiveness of electricity generation from biogas in the base project. Conversely, organic fertilizer price was more influential in the alternative project. Nonetheless, risk analyses show similar results for both scenarios, mainly due to fucoidan extract selling price and CAPEX estimates uncertainties. [ABSTRACT FROM AUTHOR]

Biomass is nearly carbon neutral and can be used for the production of various liquid fuels and chemicals. Decisions on biomass utilization should be based on the most economical and mature route. This study analyzes mountain pine beetle (MPB) killed wood as the feedstock for production of bio-ethanol and bio-oil and compares it with the direct combustion route to produce electricity. The MPB infestation of British Columbia’s (BC), a western province of Canada, forest has reached an epidemic proportion and is spread over an area of 10 millionha. According to the current estimates of BC‘s Ministry of Forests and Range, about 1 billion m3 of trees would be killed by MPB by 2013. This infestation would result in large scale loss of jobs and the standing dead trees are a fire hazard and if left unharvested will decay and release carbon back to the atmosphere. The cost of bio-ethanol production from a 2100dry tonne/day plant using the infested wood for two locations (one remote and other near the industry) in BC is in the range of C$0.37–C$0.40/l (C$1.40–C$1.51/gallon). Similarly, cost of bio-oil production from a 220dry tonne/day plant using the infested wood for same two locations in BC is in the range of C$0.27–C$0.29/l (C$1.02–C$1.09/gallon). The cost of producing electricity using this bio-oil is above C$100/MWh which is higher than the current power price in BC. This cost is also higher than the cost of production of electricity by direct combustion of infested wood in a boiler (C$68–C$74/MWh). [Copyright &y& Elsevier]

[Display omitted] • Simultaneous effect of KOH and biochar was studied on hydrolysis and syntropy. • Taguchi based design of experiment was coupled with grey relation analysis. • 0.5 g/100 g straw of alkali and 10 g/L of biochar was the optimised dosing. • Techno-economic analysis showed US$ 25,652 of NPV and 11.29% IRR. The present study investigated the effect of alkali and biochar addition for simultaneous increment of hydrolysis and syntropy for higher methane yield from pearl millet straw (PMS) in solid state anaerobic digestion. A taguchi based design of experiment was coupled with grey relation analysis for multiple output optimization. Study showed that 0.5 g (g/100 g PMS) of alkali and 10 g/L of biochar was the optimised dosing. Statistically, contribution of biochar and alkali was 48 and 21% respectively on the multiple output. The confirmation test revealed that hydrolysis rate constant, k and total volatile fatty acid/alkalinity ratio for reactor having optimised conditions was 0.0521 d-1 and 0.36 while for control, it was 0.0595 d-1 and 0.76 respectively. Techno-economic assessment showed US$ 25,652 of net present value and 11.29% of internal rate of return. Sensitivity analysis showed that capital expenditure and methane yield was most sensitive to net present value. [ABSTRACT FROM AUTHOR]

• Modeling of algae biomass production costs and productivities in the Arabian Gulf. • Raceway ponds and flat panel reactors most feasible option for regional production. • Lowest biomass production costs of 2.9 €·kg−1 found for open raceway ponds. • Scale-up from 1 to 10 ha has most impact on cost reductions. • Increased photosynthetic efficiency and temperature optima reduce costs up to 42.5% The Arabian Peninsula's advantageous climate, availability of non-arable land, access to seawater and CO 2 -rich flue gas, make it an attractive location for microalgae biomass production. Despite these promising aspects, the region has seen very few studies into the commercial feasibility of algae-based value chains. This work aims to address this gap through a techno-economic feasibility study of algae biomass production costs, comparing different photobioreactor types, locations, and production scales. Flat panel and raceway pond cultivation systems were found to be the most economically attractive cultivation systems, with biomass production costs as low as 2.9 €·kg−1. Potential cost reductions of up to 42.5% and 25% could be accomplished with improvements in photosynthetic efficiencies and increased culture temperatures, respectively. As of such, efforts to source local thermo- and photo- tolerant strains could be the key to unlock the potential of the region for algae commercialization, linking into food, feed and nutraceutical industries. [ABSTRACT FROM AUTHOR]

• Min. biochar price is between € 436 and € 863 per tonne in conventional pyrolysis. • Min. biochar price is between € 564 and € 979 per tonne in microwave pyrolysis. • Conventional pyrolysis is more viable than microwave pyrolysis. • Biochar price determines a biochar production plant's feasibility. A comparative techno-economic assessment and Monte Carlo risk analysis is performed on large scale (3 tonne/h) biochar production plants for conventional (CPS) and microwave (MWP) pyrolysis using six different residue streams. Both plants are viable with minimum selling prices between € 436/tonne and € 863/tonne for CPS, and between € 564/tonne and € 979/tonne for MWP. The CPS is therefore more viable than MWP as it is a simpler and more established technology. However, a 20% biochar price increase due to higher biochar quality makes the MWP technology more viable. Nevertheless, the discounted payback period remains higher than this of CPS due to the increased CAPEX. Biochar price is the most important determinant of a biochar production plant's feasibility, motivating the need for economic and market research on biochar prices in function of biochar characteristics to reduce fluctuations in widely varying biochar prices. [ABSTRACT FROM AUTHOR]

• Techno-economic study of sophorolipid production using SuperPro Designer®. • Combined strategy of fed-batch fermentation and in-situ separation was developed. • Production of sophorolipid crystals or syrup as end product was economically feasible. • The NPV and IRR were US$183,598,000 and 36.17%, respectively. • Purchase of equipments from Mainland China reduced payback period by 1.65 years. This study evaluates the techno-economic feasibility of sophorolipid (SL) production process that co-utilizes food waste, glucose and oleic acid as substrates. Two variables are considered in terms of (a) Plant construction: Purchasing equipment either from the US or Mainland China and (b) Production: to produce SL crystals (about 97% active) or a concentrated SL liquid/syrup (about 78% active). Hence, four scenarios are generated: Scenario I: equipment made in the USA + SL crystals; Scenario II: equipment made in the USA + SL syrup; Scenario III: equipment made in China + SL crystals; Scenario IV: equipment made in China + SL syrup. It is found that all scenarios are economically feasible and Scenario I has the highest net profit. Scenario III has the highest internal rate of return, net present value and the shortest payback period at a 7% discount rate. Finally, comparison of food waste-related techno-economic studies was conducted. [ABSTRACT FROM AUTHOR]

• An integragted algal biorefinery by four microalgae-to-products chains is illustrated. • The techno-economic assessment establishes through the estimation of CAPEX and OPEX. • The life cycle assessment associated with all the stages in an integrated algal biorefinery. • The PSE approaches are suitable for solving the microalgae processing optimization problem. In the light of microalgae rich in proteins, carbohydrates, and lipids, development of multi-product biorefinery from microalgae has become a promising approach towards commercialization of microalgae-based products. This review discusses an integrated algal biorefinery (IABR) based on a combination of four microalgae-to-products chains for the production of biofuels, biopower, and byproducts. Two systematic analytical approaches by life cycle assessment (LCA) and techno-economic assessment (TEA) are used to quantify the economic and environmental benefits. From process systems engineering (PSE) aspects, the approach procedures include that (i) the engineering process model serves as the foundation for assessment, (ii) an IABR is generated via process design, simulation, and integration, and (iii) the multi-objective optimization of an IABR with respect to economic and environmental issues is addressed. [ABSTRACT FROM AUTHOR]

• Techno-economics of lignocellulose biorefineries via chemical means were assessed. • Dilute acid pretreatment had a lower production cost than steam explosion. • A high capital cost of the integrated CHP plant negatively affected profitability. Global concerns about depletion of fossil reserves has driven countries towards bio-economies utilising mostly first generation feedstocks. The economic viability of energy self-sufficient biorefineries processing sugarcane lignocelluloses into sorbitol or glucaric acid and electricity was investigated. Aspen Plus® simulations represented glucose conversion processes via SO 2 -steam explosion or dilute acid pre-treatment, followed by enzymatic hydrolysis. The most economically viable sorbitol scenario using dilute acid pretreatment with a capital investment cost per litre of US$ 3.96/L was marginally profitable having a selling price 5% below the US$ 655/t market price. To secure private investment, the sorbitol selling price should reach US$ 1283/t. [ABSTRACT FROM AUTHOR]