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Parabolic trough concentrating solar technology (PTC) is the most deployed technology among all solar thermal technologies. The conventional receivers (heat collection elements, HCEs) suffer from issues of high-technology fabrication, high cost and frequent operational failures. This work proposes a novel parabolic trough receiver design which is facile to fabricate, maintain and repair for long-run solar field operation. The novel receiver is tested experimentally (by indoor heat loss testing) to validate a comprehensive numerical model which is then used to simulate various cases. Effect of inclination angle, absorber temperature, surface emissivity, aperture angle and thermal contact resistance are quantitatively studied by the two-dimensional numerical model incorporating natural convection and surface radiation. The resulting thermal performance is compared with standard evacuated commercial HCEs. Whereas commercial evacuated HCEs cost between 250 and 350 $/m, we show that the novel receiver costs only 42 $/m. Insights from the detailed numerical model are incorporated into a technoeconomic comparison of a solar field raising thermic fluid by 100 K from 566 K and fitted with the novel receiver and the Schott PTR HCE. The difference in cost is about 6%. • A novel heat collection element for parabolic trough concentrators proposed. • Indoor heat loss testing of novel receiver conducted. • 2D numerical model developed and experimentally validated. • Design costs 42 $/m against 250–350$/m for commercial designs. • Solar field with novel receiver is as cost effective as that with commercial designs. [ABSTRACT FROM AUTHOR]

[Display omitted] • Technoeconomic analysis of DES and IL catalysis of biomass was performed. • Annual operating cost was highly associated with DES/IL recycling time. • Acetone/water washing volume determined the chemical recovery cost of the refinery. • Lactic acid and [EMIM]Cl unit costs were dominant contributors to the HMF MSP. 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 (ZnCl 2 -lactic acid)/IL([EMIM]Cl)/metal catalysts (CuCl 2 -CrCl 2) 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 (ZnCl 2 /lactic acid recycling 5 times, acetone/water washing 5 volumes, CuCl 2 -CrCl 2 -[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. [ABSTRACT FROM AUTHOR]

Global optimization for sustainable design and synthesis of a large-scale algae processing network under economic and environmental criteria is addressed. An algae processing network superstructure including 7800 processing routes is proposed. Based on the superstructure, a multiobjective mixed-integer nonlinear programming (MINLP) model is developed to simultaneously optimize the unit cost and the unit global warming potential (GWP). To efficiently solve the nonconvex MINLP model with separable concave terms and mixed-integer fractional terms in the objective functions, a global optimization strategy that integrates a branch-and-refine algorithm based on successive piecewise linear approximations is proposed and an exact parametric algorithm based on Newton's method. Two Pareto-optimal curves are obtained for biofuel production and biological carbon sequestration, respectively. The unit annual biofuel production cost ranges from $7.02/gasoline gallon equivalent (GGE) to $9.71/GGE, corresponding to unit GWP's of 26.491 to 16.52 kg CO2-eq/GGE, respectively. © 2014 American Institute of Chemical Engineers AIChE J, 60: 3195-3210, 2014 [ABSTRACT FROM AUTHOR]

Highlights: [•] The economics of lignocellulosic ethanol without the use of enzymes was studied. [•] The process is based on acidolysis and sugar extraction. [•] The model is intended to guide scientists in addressing key technical challenges. [•] Through process optimization, the MESP could be lowered from $8.05/gal to $4.00/gal. [ABSTRACT FROM AUTHOR]

Abstract: Microalgae have been promoted as the next frontier of green biotechnology and gained widespread attention as desirable feedstocks for biofuels. Using conservative assumptions for microalgal growth rates (15gm−2 d−1) and total lipid content (25%), the entire “pond-to-pump” lifecycle of algal biofuels for 1000bbld−1 of crude algae oil production is modeled with approximately 4875ha of raceway ponds for solar collection and cultivation and 1463MLD (385MGD) of water handling capacity in the current analysis. Technoeconomic analysis based on an array of 6000 modular 0.8ha (2acre) paddlewheel-driven ponds in New Mexico identified several cost barriers and resources challenges (i.e., nutrient and water resources). For 10- and 20-year capital return scenarios, the cost of algal oil production – $4.10L−1 ($15.52gal−1) and $3.21L−1 ($12.14gal−1), respectively – requires substantial capital and facility maintenance investments with principal cost sensitivities attributed to extraction efficiency and lipid content. Baseline conditions result in an energy return on investment (EROI) of 2.73. Uncertainty in energy requirements for paddlewheels as well as water supply and circulation significantly affect the EROI and operating costs. Alternative strategies to address the major cost barriers are needed for algal biofuels to realize their full potential. [Copyright &y& Elsevier]

Abstract: Typically in algae farm economic feasibility analyses capital expenses (CAPEX), operating expenses (OPEX), and other parameters are assumed at the outset. In the reverse engineered algae farm (REAF) approach the production level is specified and then CAPEX, OPEX, and other parameters are set to provide a high probability of success. The Farm-level Algae Risk Model (FARM) is used for a technoeconomic analysis of a REAF farm. The analysis incorporates production, price, and financial risks the farms will likely face over a 10-year period. The base values assumed for CAPEX and OPEX are $20,000,000 and $3,600,000. Average production for the 485ha farm is approximately 600,000gal of lipid and 10,000tons of lipid extracted algae per year. The base farm did not have a high probability of success; so, a sensitivity analysis for reductions in CAPEX and OPEX and increases in biomass production and lipid content were conducted. To generate a 95% or greater probability of economic success, 40% reductions in OPEX and CAPEX and 10% increases in biomass production and lipid content will be required. There are numerous scenarios which generate a 95% or greater probability of success but they require additional reductions in CAPEX. [Copyright &y& Elsevier]

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., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

[Display omitted] • A novel process for EG and LNG from steel mill off-gases is proposed. • Exergy efficiency of the proposed process is improved by 10.05%. • Total production cost of the proposed process is reduced by 17.46%. • Market fluctuations have much lower impact on the proposed process than the standalone processes. Coke oven gas and Linz Donawitz gas are pollutive off-gases of steel mill plants. Their potential chemical value can be used to produce high value-added chemicals and fuels by means of coproduction. Thus, a novel coproduction system for ethylene glycol and liquid natural gas from steel mill off-gases (CG-ELNG) is proposed and optimized through a rigorous process modeling and simulation. The thermodynamic and technoeconomic performance of the proposed process are analyzed and compared with the conventional standalone ethylene glycol and liquid natural gas production processes. Results show that the optimal feed ratio of coke oven gas and Linz Donawitz gas is 2.42 to have the most suitable hydrogen to carbon ratio and the highest resource utilization efficiency of the proposed processes. The exergy efficiency of the process is high to 60.45%, which is 10.05% higher than that of the standalone off-gases based ethylene glycol production process. The total production cost is reduced by 17.46%, and internal rate of return is improved by 7.47% in comparison with the standalone processes. In addition, the sensitivity analysis results reveal that the fluctuations of raw material, utilities consumption, and production capacity have much lower impact on the proposed process than the standalone processes. Therefore, the findings of this study provide a newly promising direction for highly efficiently utilization of steel off-gases. [ABSTRACT FROM AUTHOR]

The development of technologies that utilize carbon dioxide is important to mitigating climate change. The electrochemical reduction of carbon dioxide is one technology that can utilize greenhouse gasses that would be otherwise be emitted to the atmosphere by producing chemicals and fuels from carbon dioxide and electricity. Significant progress has been made in the experimental performance of carbon dioxide reduction systems with novel catalyst designs, new materials, and systems engineering; however, no work has linked such changes in stack design and materials to capital costs for the stack itself. Here we present an analysis that accounts for and analyzes the impacts of alternative materials and system architectures on manufactured costs of carbon dioxide reduction stacks, thus providing a framework to understand exactly how these advances impact the at-scale capital costs of these systems. Specifically, we consider the impact that the addition of a catholyte buffer layer has on an electrolyzer reducing carbon dioxide to formate, finding that the cost of manufacturing this part only increases stack costs by about $30/m2 at high manufacturing rates, while previous work finds that this part improves system performance. This work shows that the links between system performance, materials, and costs are nonlinear, and that achieving low-cost scalability requires optimization of not just performance parameters but also the use of low-cost and highly scalable materials. These results bridge experimental and techno-economic analysis of processes for carbon dioxide reduction, informing researchers by providing a quantifiable estimate of the impact of advances in electrochemical carbon dioxide reduction technology on manufactured stack capital costs. • Estimates of manufactured cost of carbon dioxide reduction stacks are presented. • Costs of two carbon dioxide reduction stack architectures are discussed. • Case study estimating the economic impact of recent experimental advances is given. • Cost optimization requires consideration of materials, performance, and scalability. [ABSTRACT FROM AUTHOR]

[Display omitted] • Novel PEM-CTEG and SOEC-CTEG processes are proposed and modeled. • Technical and economic performance of the proposed processes is detailed analyzed. • Proposed processes increase carbon efficiency 21% and reduce CO 2 emissions by 84%. • Proposed processes increase exergy efficiency by 8%–14% and IRR by 3–10%. • Proposed processes have better anti-risk ability of coal and ethylene glycol prices. Many Belt and Road Countries are actively taking measures to achieve carbon peaking and carbon neutrality. It greatly promotes to transform and upgrade the coal based chemical industries. This study proposed a coal-to-ethylene glycol process integrated with proton exchange membrane electrolyzer (PEM-CTEG) and a process integrated with solid oxide electrolysis electrolyzer (SOEC-CTEG) technologies to address the shortcomings of traditional process such as high carbon emissions and unreasonable process structure. The proposed processes are integrated with different renewable energy-based hydrogen production technologies to balance the hydrogen and carbon elements in the system to achieve carbon neutrality. Techno-economic performance of the two proposed processes is analyzed and compared with a traditional CTEG process based on the modeling and simulation of the processes. The results show the carbon utilization efficiency of the proposed processes are increased by 20.64%, and the CO 2 emissions are reduced by 84.01%. The exergy efficiency of the PEM-CTEG and SOEC-CTEG processes is enhanced by 8.29% and 13.98%, and the internal rate of return is improved by 3.50% and 10.09%, respectively. In addition, the influence of the fluctuations of the key economic factors on the economic performance of the two proposed processes is studied through a sensitivity analysis. Results show that the proposed processes have better anti-risk ability of the fluctuations of coal and ethylene glycol prices. Thus, the proposed PEM-CTEG and SOEC-CTEG processes can effectively improve the techno-econo-environmental performance of traditional process, and have promising industrialization prospect. [ABSTRACT FROM AUTHOR]

While many papers report biomethanation potential of various substrates subjected to various treatments, very few report the economic implications of their work. Here, we report a simple but effective mechanistic model, using Contois and Monod kinetics, considering only two classes of micro-organisms (a) acidogens and (b) acetomethanogens. We fitted our model to CH 4 and CO 2 evolution data from biomethanation studies of water lettuce (pistia stratiotes) inoculated with buffalo dung at five different ratios of substrate to inoculum. The data was obtained by gas chromatography. The model has been used to simulate three types of biodigestors: (a) 1-stage continuous digestor, (b) 2-stage continuous digestor and (c) semi-batch digestor with intermittent draining of digestate. The 2-stage digestor exhibited no major improvement over the 1-stage digestor presenting only a 4% increase in methane production rate with 25% longer response times. The best performance was shown by the semi-batch operation due to tolerance of high microbial loads. Biogas generated from water lettuce grown on a farm pond and using the semi-batch approach can be monetized by offsetting use of market bought LPG. The return on investment is 24.7% and 25 kg of CO 2 emissions are abated per ton of water lettuce utilized. [Display omitted] • Simple, effective mechanistic model using Contois and Monod kinetics for bioreactor design developed. • Pistia Stratiotes inoculated with buffalo dung used for biomethanation potential experiments. • Model calibrated with CO2 and CH4 evolution data from experiments. • Several reactor configurations simulated using the model. • Semi-batch 1-stage is optimum configuration, with 24.7% RoI for LPG offset. [ABSTRACT FROM AUTHOR]

During these times of fluctuating freight rates and oversupply, selection of optimum speed will give an operator a crucial advantage. Until the recession, the emphasis has always been on larger capacity and higher speed. Now, design innovation and slow steaming are becoming important and this article details new software, which is set up to assist the speed optimization process for large container ships. The software uses both propulsion and revenue-cost analysis with an ultralarge container ship model of 20,000 20-ft.unit (TEU) as a case study to derive the most profitable speed. Shippers' costs are also estimated to assess the impact on shippers. This software can be used for new construction or existing ships. The results show that 19.5 knots is the optimum speed, which is a departure from the current trend of 25 knots but supporting the concept of slow steaming. The results are validated by Det Norske Veritas container cost models. Besides that, the multivariable nature of the optimum speed problem is discussed and further analysis has been carried out to determine the range of fuel cost, freight rate, and load factor in which this optimum speed is applicable (in this case, $1100/TEU < freight rate < $1300/TEU, $650/MT < fuel cost < $750/MT and load factor = 40%). This will be useful to ship operators for forecasting purposes. [ABSTRACT FROM AUTHOR]

Abstract: The economic feasibility of a facility producing monosaccharides, hydrogen and transportation fuels via fast pyrolysis and upgrading pathway was evaluated by modeling a 2000 dry metric ton biomass/day facility using Aspen Plus®. Equipment sizing and cost were based on Aspen Economic Evaluation® software. The results indicate that monosaccharide production capacity could reach 338 metric tons/day. Co-product yields of hydrogen and gasoline were 23.4 and 141 metric tons/day, respectively. The total installed equipment and total capital costs were estimated to be $210 million and $326 million, respectively. A facility internal rate of return (IRR) of 11.4% based on market prices of $3.33/kg hydrogen, $2.92/gal gasoline and diesel, $0.64/kg monosaccharide was calculated. Sensitivity analysis demonstrates that fixed capital cost, feedstock cost, product yields, and product credits have the greatest impacts on facility IRR. Further research is needed to optimize yield of sugar via the proposed process to improve economic feasibility. [Copyright &y& Elsevier]

During these times of fluctuating freight rates and oversupply, selection of optimum speed will give an operator a crucial advantage. Until the recession, the emphasis has always been on larger capacity and higher speed. Now, design innovation and slow steaming are becoming important and this article details new software, which is set up to assist the speed optimization process for large container ships. The software uses both propulsion and revenue-cost analysis with an ultralarge container ship model of 20,000 20-ft.unit (TEU) as a case study to derive the most profitable speed. Shippers' costs are also estimated to assess the impact on shippers. This software can be used for new construction or existing ships. The results show that 19.5 knots is the optimum speed, which is a departure from the current trend of 25 knots but supporting the concept of slow steaming. The results are validated by Det Norske Veritas container cost models. Besides that, the multivariable nature of the optimum speed problem is discussed and further analysis has been carried out to determine the range of fuel cost, freight rate, and load factor in which this optimum speed is applicable (in this case, $1100/TEU < freight rate < $1300ATEU, $650/MT < fuel cost < $750/MT and load factor = 40%). This will be useful to ship operators for forecasting purposes. [ABSTRACT FROM AUTHOR]

Abstract: The addition of a biorefinery to an organic farm was investigated, where ethanol was produced from germinated rye grains and whey, and the effluent was separated into two streams: the protein-rich solid fraction, to be used as animal feed, and the liquid fraction, which can be co-digested with clover grass silage to produce biogas. A method for ethanol production from rye was applied by utilizing inherent amylase activity from germination of the seed. Biogas potential of ethanol fermentation effluent was measured through anaerobic digestion trials. The effluent from the trials was assumed to serve as natural fertilizer. A technoeconomic analysis was also performed; total capital investment was estimated to be approximately 4MUSD. Setting a methane selling price according to available incentives for “green electricity” (0.72USD/m3) led to a minimum ethanol selling price of 1.89USD/L (project lifetime 25yr, at a discount rate 10%). [Copyright &y& Elsevier]

Abstract: A sustainable business model is necessary for viable and future proof fiber-based Metropolitan Area Networks (MANs), in light of FTTH/O developments, which necessitate public initiatives, towards the leverage of broadband adoption. Following a detailed analysis and benchmarking of international practices, a pool of business solutions for the MANs development, especially for the Greek case, is presented. Taking into account pros and cons, a set of four appropriate business models is analyzed, and a quantitative financial analysis concludes the findings. Guidelines for the further development of these initiatives, useful for other countries with low broadband penetration, are presented and discussed. [ABSTRACT FROM AUTHOR]

The concept of cofiring (algal biomass burned together with coal or natural gas in existing utility power boilers) includes the utilization of CO2 from power plant for algal biomass culture and oxycombustion of using oxygen generated by biomass to enhance the combustion efficiency. As it reduces CO2 emission by recycling it and uses less fossilfuel, there are concomitant benefits of reduced greenhouse gas (GHG) emissions. The by- products (oxygen) of microalgal biomass can be mixed with air or recycled flue gas prior to combustion, which will have the benefits of lower nitrogen oxide concentration in flue gas, higher efficiency of combustion, and not too high temperature (avoided by available construction materials) resulting from coal combustion in pure oxygen. A technoeconomic analysis of microalgae cofi ring process for fossil fuel-fired power plants is studied. A process with closed photobioreactor and artificial illumination is evaluated for microalgae cultivation, due to its simplicity with less influence from climate variations. The results from this process would contribute to further estimation of process performance and investment. Two case studies show that there are average savings about $0264 million/MW/yr and $0203 million/MW/yr for coal-fired and natural gas-fired power plants, respectively. These cost savings are economically attractive and demonstrate the promise of microalgae technology for reducing GHG emission from fossil fuel-fired power plants. [ABSTRACT FROM AUTHOR]

Abstract: We present a process model for a lignocellulosic ethanol biorefinery that is open to the biofuels academic community. Beyond providing a series of static results, the wiki-based platform provides a dynamic and transparent tool for analyzing, exploring, and communicating the impact of process advances and alternatives for biofuels production. The model is available for download (at http://econ.jbei.org) and will be updated based on feedback from the community of experts in biofuel-related fields. By making the assumptions and performance metrics of this model transparent, we anticipate this tool can provide a consensus on the energy-related, environmental, and economic performance of lignocellulosic ethanol. [Copyright &y& Elsevier]

[Display omitted] • Bioconversion of soybean hulls and transgenic poplar to acetone and green H 2. • Bioproducts from extremely thermophilic fermentation are industrially feasible. • Hydrogen co-production with acetone significantly improves process economics. • Acetone preferred to ethanol to optimally allocate reducing equivalents. 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 H 2 per metric ton of soybean hull, or 174 kg acetone and 21 kg H 2 per metric ton transgenic poplar. Beyond this specific case, the model demonstrates industrial feasibility and economic advantages of thermophilic fermentation. [ABSTRACT FROM AUTHOR]

• Indirect MA production based on DME using FER@FER catalyst from shale gas. • Four different syngas production processes including DRM, POX, SRM, and TRM. • The economic feasibility of proposed MA production processes. Shale-gas-derived methyl acetate (MA) production is an energy-efficient value-added chemical process. Therefore, we first simulated dimethyl ether (DME) production process from shale-gas-derived syngas (CO/H 2) by controlling the syngas composition using a membrane separation process and then converted the resulting DME into MA as a proof-of-concept strategy. Our proposed integrated MA synthesis process consisted of syngas production (including Matrimid® 5218 membrane separation), DME production/separation (Cu–ZnO–Al 2 O 3 /ferrierite catalyst), and MA production/separation (FER@FER catalyst). In addition, the DME-based MA yield and selectivity were determined using a fixed-bed reactor, and the results were applied to the Aspen PlusTM simulator to describe the overall MA production process from shale-gas. Our proposed MA production process enabled continuous MA production from shale gas and simultaneous H 2 production. Furthermore, the proposed catalyst increased MA selectivity to 97% and exhibited relatively high conversion (27.82%) of DME to MA in excess CO. Most importantly, our rigorously mathematically modeled technoeconomic analysis (TEA) estimated that the MA production costs were approximately 0.71, 0.64, 0.60, and 0.63 $/kg MA for dry reforming of methane, partial oxidation, steam reforming of methane, and tri-reforming of methane syngas production methods, respectively. The net present values (NPVs) of the respective processes were 617, 525, 667, and 835 MM$ during 30 years of plant operation. Such low MA production costs and relatively high NPVs were comparable to those of the most mature conventional MA production processes (0.95 $/kg MA) owing to enhanced membrane-separation-based DME production and selective recycling streams, thereby supporting the feasibility of industrially producing MA using syngas-derived DME intermediates. [ABSTRACT FROM AUTHOR]

The impact of regulatory pressure to reduce international mobile roaming (IMR) charges, especially in Europe, and the potential competition from other technology alternatives will be the main motivations for existing mobile operators to find solutions that will reduce the cost of operations and increase maintain the revenue margins, while maintaining control over subscribers. This article provides an overview of the changing business dynamics of IMR. analyzes the existing and emerging IMR scenarios, and proposes a mechanism that addresses the technological disadvantages of existing ones. The article also evaluates the business implications of the proposed mechanism vis-a-vis ihe preferred roaming scenario of today (i.e.. home routed traffic) from a mobile operator's point of view. [ABSTRACT FROM PUBLISHER]

The Institute for Prospective Technological Studies (IPTS) as part of the European Union (EU) Commission''s Joint Research Centre (JRC) provides technoeconomic analysis support to European decision-makers, by monitoring and analysing science and technology (S/T)-related developments, their cross-sectoral impact, their interrelationship with the socioeconomic context, and their potential future policy implications. The effects of S/T on the economic context are multiple, including the opening up of new markets, the increase or decrease of competition in an industry, the location of production of goods/services, the demand for factors of production such as labour and capital, the implications for skills demand, the consequences for wages and employment, the environmental impact, etc. Given informational asymmetries, policy-makers need ways to extract useful information regarding S/T developments and their potential economic implications, and can benefit from policy-sensitive analysis from knowledgeable impartial sources of information. Since S/T innovations have important economic implications (and are themselves influenced by economic incentives), the better one can anticipate them, the more successfully one can adapt. What is crucial here is the capacity to think through the prospective implications of S/T developments, and foster the kinds of institutions and incentives that will make successful adaptation part of the normal working of the economy, rather than the results of ad hoc re-active policies. [Copyright &y& Elsevier]

[Display omitted] • There is sufficient camelina land in the United States to produce aviation biofuel. • Energy demand in olefin metathesis is similar to hydroprocessed renewable jet. • Increasing camelina yield reduces greenhouse gas emissions of olefin metathesis. • Olefin metathesis biorefinery achieves annual profit without tax incentive. This study performed a holistic assessment of a novel cracking alternative (olefin metathesis or OMT) that converts plant oil to aviation biofuel using lipids from Camelina sativa L. (camelina). A high-resolution spatially explicit life cycle assessment and technoeconomic analysis (HR + LCA + TEA) was employed to elucidate camelina's sustainability case. The potential camelina land was determined via the wheat-fallow Integrated Rotational Cycle (IRC) at county level for the 48 lower states in the U.S. Results revealed these lands were aggregated on the top wheat producing states of Montana, Kansas, and North Dakota at 19.5 × 106 ha, 18.2 × 106 ha, and 19.2 × 106 ha, for 2009, 2012, and 2015, respectively. If the high producing wheat lands (counties with >60,000–80,000 ha) in those states were grown with camelina at U.S. average yield of 1.2 Mg/ha, around 6.35 million m3 (1.68 billion gal) of advanced biofuel will be produced, equivalent to 11.18 % of the expanded Renewable Fuel Standard (RFS2) volume mandate for advanced biofuel (15 billion gal). LCA results using 1 MJ functional unit and "well-to-air" (WTA) system boundary showed that the operations cumulative energy demand (CED) for the OMT case producing simultaneous biojet, avgas, and diesel was 0.75 MJ/MJ, lower than for hydroprocessed renewable jet (HRJ) fuel (0.77 MJ/MJ) but 6.8 times higher than for petroleum jet (PTJ) fuel (0.11 MJ/MJ). The entire OMT energy demand was offset by the bioelectricity produced (0.57 MJ/MJ) from burning the meal. OMT's net GHG reduction relative to PTJ was 23.34 % but increasing camelina yield from 1.2 to 1.8 Mg/ha increased reduction to 75.71 %. TEA results adapting 100,000 m3/yr biofuel throughput showed that OMT and HRJ had profits of $21.94 M and $24.13 M, respectively, using mass product allocation. The limiting metric for OMT and HRJ was net present value (NPV), and the minimum camelina yield to ensure profit was 1.18 Mg/ha. OMT can achieve maximum profit by selling biojet fuel at a price not lower than $2.75/gal and selling camelina meal feed pellets at a minimum price of $330/Mg. No tax incentive was needed for biojet and avgas because even at their base median values (biojet = $2.19/gal, avgas = $2.59/gal), NPV is still positive. [ABSTRACT FROM AUTHOR]

The utilization of crude waste streams and the development of novel bioprocessing routes are necessary in order to expand the industrial implementation of bio-based succinic acid production. This work focuses on the utilization of zero cost municipal organic biowaste for the production of bio-based succinic acid using the engineered yeast strain Yarrowia lipolytica PSA02004. Fermentation advances focused on pH regulation towards reduced NaOH requirements. Optimum initial carbon source concentration (100–120 g/L) in crude hydrolysates was estimated in shake flask cultures. Optimum k L α (183.2 h−1) in fed-batch cultures resulted in 42.2 g/L succinic acid with 0.38 g/g yield and 0.84 g/L/h productivity. A two-stage pH regulation strategy was employed to enhance succinic acid production efficiency and reduce NaOH requirements. The gradual reduction of pH from 6 to 5.5 resulted in 54.4 g/L succinic acid with 0.44 g/g yield and 0.82 g/L/h productivity and 43% lower NaOH consumption. The minimum selling price of succinic acid was estimated at $2.7/kg and $2.94/kg at annual production capacity of 50,000 t when the production cost of organic biowaste derived sugars were considered at $10/t TS and $110/t TS , respectively. The global warming potential and abiotic depletion potential were estimated at 2.72 kgCO 2 -eq/kg SA and 33.4 MJ/kg SA , respectively. Results showed that pH regulation is an important operating parameter towards the sustainable succinic acid production using municipal organic biowaste. • Fermentation optimisation (pH and k L α) of genetic engineered Yarrowia lipolytica. • Succinic acid was efficiently produced using the municipal bio-waste. • A two-stage pH regulation led to significant reduction of NaOH requirements. • The developed process was evaluated via technoeconomic and life cycle analysis. [ABSTRACT FROM AUTHOR]

• Economic analysis for three direct air capture of CO 2 to syngas plants. • Thermocatalytic reverse water gas shift, gaseous CO 2 electrolysis, and direct (bi)carbonate electrolysis of alkaline carbon capture solution were studied. • Trade-offs between unit price and net CO 2 electrolysis were found. • Direct electrolysis of carbon capture solution can be cost competitive. Producing syngas, a blend of CO and H 2 , is the starting point to the large-scale production of valuable chemicals including fuels and methanol. This study evaluates pathways for syngas production from air-captured and tail-gas captured CO 2 in terms of net CO 2 emissions, energy efficiency and associated costs. We analyzed three direct air capture (DAC) to syngas plants (H 2 /CO = 2.5, suitable for Fischer Tropsch or methanol synthesis) that perform the CO 2 -reduction step by either: i) thermocatalytic reverse water gas shift (rWGS); ii) gaseous CO 2 -electrolysis, and iii) direct (bi)carbonate electrolysis of the carbon capture solution. The gaseous electrolysis plant did not offer any advantage over the thermolytic rWGS because it implied similar net CO 2 emissions (equivalent to 50% of the CO 2 captured initially), even if renewable electricity is used. The carbon footprint of the gas CO 2 -electrolysis pathway originates in the calcination step for the CO 2 recovery from the air and tail-gas capture solutions. Only a significant improvement in state-of-the-art single pass conversion of CO 2 in gas CO 2 -electrolyzers (10–30%) would decrease the associated CO 2 emissions. In contrast, the novel DAC-(bi)carbonate electrolysis offered the best pathway in terms of net CO 2 emissions. However, it entailed higher syngas costs (1.90 $ kg −1) compared to gaseous electrolysis (1.30 $ kg−1) or the conventional rWGS (1.1 $ kg−1) pathways. The DAC-carbonate electrolysis plant may become cost-competitive with reasonable improvements in performance, mainly faradaic efficiency to CO and cell voltage, electricity price ≤ 35 $ MWh−1 and membrane price < 450 $ m−2. Even in the best case scenario all the CO 2 -based alternatives entailed a higher levelized cost of syngas, synfuel or methanol than current retail prices. [ABSTRACT FROM AUTHOR]

We report a process that can use a modified turbocharged piston engine to simultaneously heat-treat aqueous streams and produce electricity. The additional electricity generated by this process more than offsets the cost of heat-treating aqueous stream: thus opening up for commercial utilization water treatment approach that was hitherto considered cost prohibitive. The process provides the technological means for remote or off-grid communities to simultaneously treat their aqueous wastes and generate electricity. In this work, we present a detailed technoeconomic evaluation of the process to demonstrate both its technical feasibility and its cost effectiveness. The variation in overall efficiency, specific work, low-grade heat efficiency and treatment cost of the aqueous stream is studied as a function of turbocharger exit pressure, piston engine compression ratio and mass flow ratio of the aqueous stream to air. For an optimized process, the overall efficiency of the system is 50%. The cost of aqueous stream treatment is negative at −0.998 US$ per cubic meter of water treated based on a 15% return on incremental investment. • Process to simultaneously heat treat aqueous streams and produce electricity. • Exergy of hot aqueous streams recovered as electricity with high efficiencies. • Simple process to generate electricity from low-grade or waste heat. • Power generated shown to offset cost of heat treatment of aqueous streams. [ABSTRACT FROM AUTHOR]

Coal to ethylene glycol technology has been fruitfully developed due to the abundant reserve of coal and the low production cost. However, its sustainable development is plagued by the high CO 2 emissions. Hence, a novel coal to ethylene glycol process integrated with methane tri-reforming technology is proposed, simulated, and optimized for low carbon emission and high efficiency. The effects of the key operational parameters on the performance of the proposed process are analyzed and optimized along with the established rigorous system modeling and simulation models. Results show the optimal ratio of coke oven gas and coal of the proposed process is 95 kmol/t, the optimal ratio among CH 4 , CO 2 , H 2 O and O 2 of the tri-reforming unit is 1: 1.43: 2.15: 0.44, and its optimal temperature is 850 °C. Compared with the conventional process, the carbon and exergy efficiencies of the proposed process are increased by 50.94% and 15.16%, the capital investment and production costs are saved by 16.1% and 14.3%, and the direct CO 2 emission is reduced by 98.06%. Therefore, it is a promising method for coal based chemical processes to integrate methane tri-reforming technology to save energy and reduce carbon emissions. • Novel integrated scheme for CtEG process with high efficiency and low emission is optimal designed. • Effects of the key operational parameters of the proposed process are investigated and optimized. • Introducing advanced methane tri-reforming increases carbon and exergy efficiencies by 51% and 15%. • Total capital investment and production costs are saved by 16.1% and 14.3%. • Direct CO 2 emission is reduced by 98% by efficient complementarity of carbon and hydrogen elements. [ABSTRACT FROM AUTHOR]

• The optimum cost of production of enriched oxygen (>90 wt%) using membranes is US$0.05–0.07/kg. • Membrane processes can produce enriched oxygen cost-effectively at a smaller scale. • Improvement in membrane oxygen permeability is the most important factor for the improved cost of production. Enriched oxygen is a valuable commodity and has a range of applications including coal-gasification and uses in the chemical industry. Enriched oxygen can be obtained from air using different processes, such as cryogenic distillation, pressure swing adsorption, membrane-based air separation, etc. Air can be separated into component gases using membranes that do not require any regenerative steps and the products can be directly used or discharged. To understand the economics of polymer membrane-based oxygen enrichment, Idaho National Laboratory (INL) has developed a spreadsheet based technoeconomic analysis model that considered numerous parameters including selectivity and permeability of the membranes, performance conditions such as number of stages, module material, electricity cost, membrane cost, financing, etc. INL calculated the cost of production of product gas (containing an enriched O 2 content) in US$/kg gas product at different oxygen purities and compared that with cryogenic distillation and pressure swing adsorption processes. This analysis helped to determine the membrane module scale performance targets in terms of permeability and selectivity of membrane modules to be economical for use in a small modular coal-fired gasification plant (10–25 tons/day). INL determined that a double staged membrane process with the selectivity of 5.5 and permeance of 1000 GPU has a cost of gas production of US$0.05/kg for 90% pure oxygen. This production cost is lower than pressure swing adsorption and competitive with cryogenic distillation, which only meets its cost targets at a much larger scale. Similarly, a three staged membrane process with the selectivity of 3.1 and permeance of 1000 GPU has the cost of production of US$0.071/kg for 90% pure oxygen. [ABSTRACT FROM AUTHOR]