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A conceptual biorefinery process has been designed for the integration of the protein extraction and the ethanol production from brewers’ spent grain (BSG) and palm kernel meal (PKM). The conceptual process is designed for an industrial scale biorefinery annually processing 20 kton dry weight BSG and 50 kton dry weight PKM with 8000 production hours per year and is used to techno-economically analyse the performance. The techno-economic analysis showed that the biorefinery of BSG has a high economic potential with an internal rate of return of 24 %. However, despite the high raw material costs, the biorefinery of PKM still has a positive internal rate of return of 12 %. The presented virtual biorefinery demonstrated the economic potential of integrating the production of a valuable product, like protein powder for food applications, with the production of biofuel, like ethanol, from the remaining biomass, thereby valorising a larger portion of the biomass with the same raw material costs.

Enzymes are extraordinary catalysts and a preferred tool for green chemistry, but they have not evolved to tolerate the harsh conditions required in large-scale chemical processes, making the replacement of inorganic catalysts extremely expensive in most cases. However, the continuous knowledge generated by protein engineers helps to realize the promise of using biocatalysts to address critical environmental and industrial challenges. The increasing demand for food and biofuels pressures the vegetable oil industry to continuously improve its manufacturing efficiency and at the same time mitigate the environmental pollution caused by the refineries. Enzymatic degumming is a key enabling technology to obtain cleaner and more efficient methods, but advanced enzymes are needed for widespread adoption. Here, we present an enzymatic degumming process based on chPLC, a synthetic phospholipase C with remarkable thermal stability and catalytic properties. The process developed does not require modifications in current soybean oil factories, avoiding upfront investments, and is four times faster than the enzymatic processes available in the market. A techno-economic analysis predicts a ~ 60% cost reduction for a base-case scenario, establishing the largely expected conditions to promote the global adoption of enzymatic oil degumming by refineries of all sizes. To the best of our knowledge, this is the first report showing the application of a synthetic enzyme designed to address an industrial need having an impact on both the global economy and the environment, in the billion-dollar range.

This paper introduces novel modification for conventional air conditioning systems through utilizing a thermal ice storage system integrated with solar panels. Alexandria and Aswan, cities in Egypt, are chosen to represent two climates for hot-humid and hot-dry climates respectively. Exergy analysis is performed for the proposed solar-ice thermal storage system based on transient analysis. Results showed that, the proposed system is more effective approach in hot-humid than hot-dry climate and more efficient with all-water system than with all-air system. The maximum energy saving is 205.16 GJ having a percent of 27.5% in August for all water system in case of Alexandria city and 224.67 GJ with a percent of 25.38% in August for all-water system in case of Aswan city. All air system simulation showed maximum energy saving of 175.05 GJ with a percent of 18.13 % in case of August for Alexandria and 175.45 GJ having a percentage of 17.43% in case of Aswan in August. Moreover, the all-water system achieved a reduction in CO2 emissions by 467 tons/year in Aswan city and 390 tons/year in case of Alexandria city. These reductions decrease to be 435 and 353 tons/year when the all-air system used for the same two cities.

Climate change and the unsustainability of fossil fuels are calling for cleaner energies such as methanol as a fuel. Methanol is one of the simplest molecules for energy storage and is utilized to generate a wide range of products. Since methanol can be produced from biomass, numerous countries could produce and utilize biomethanol. Here, we review methanol production processes, techno-economy, and environmental viability. Lignocellulosic biomass with a high cellulose and hemicellulose content is highly suitable for gasification-based biomethanol production. Compared to fossil fuels, the combustion of biomethanol reduces nitrogen oxide emissions by up to 80%, carbon dioxide emissions by up to 95%, and eliminates sulphur oxide emission. The cost and yield of biomethanol largely depend on feedstock characteristics, initial investment, and plant location. The use of biomethanol as complementary fuel with diesel, natural gas, and dimethyl ether is beneficial in terms of fuel economy, thermal efficiency, and reduction in greenhouse gas emissions.

A techno-economic analysis is performed for a solar farm with a 35 MWe installed capacity using bifacial solar panels and compared with standard monofacial solar panels at the same installed capacity level. The bifacial panel usage gain from total panel efficiency is identified from 4-year measurements to be within a range of 7.9–16.8% depending on monthly yield. A Monte Carlo simulation is carried out to forecast electricity prices under uncertainty. In terms of Net Present Value, it is found that the bifacial farm yields 12.6% higher values than the monofacial options under reference assumptions. An incremental internal rate of return (IRR) analysis is carried out yielding an IRR for the bifacial panels of 44% under various scenarios. The sensitivity analysis reveals that results are highly sensitive to discount rate and lifetime, and less sensitive to electricity prices. SWOT analysis performed to compare the bifacial with the monofacial panel and evaluate panels according to internal and external factors. The study was concluded with a summary of the technical specifications based on the test results. The results were used to identify that 12.2% added net present value corresponding to $186.7 – $214.5 per unit MW (under various electricity price trajectories) can be used as a reference for assessing the benefit for usage of bifacial PV for 35 MW type medium-size projects. In summary, it is suggested that bifacial solar PV with its outstanding techno-economic results can be the driving force of the growing solar PV market. First published online 08 July 2022

Remote areas electrification is usually achieved through costly and eco-unfriendly diesel generator (DG) systems with additional cost-obstacles arising through diesel–fuel transportation. Hybridization of renewable energy systems (RESs) with DG units offers a dynamic approach of electrification for the remote areas. A techno-economic study is required to assess the viability of RES in such locations. This research work examines the case of Al-Shumaisi cluster, located in the west of Makkah Province, Kingdom of Saudi Arabia (KSA). This is where the Makkah transport company (MTC) is located. A techno-economic investigation is performed for a commercial load profile of MTC with a hybrid wind/DG/fuel cell/battery/electrolyzer system. In this study, two hybrid configurations are proposed: 1) wind/DG/FC/battery system; 2) wind/FC/battery system. Moreover, another configuration that uses only DG units is also investigated. A comparative study is achieved for the most optimal combination, depending on the gross present cost (GPC) and levelized cost of energy (LCOE) as the essential parameters. Furthermore, other financial parameters like operation and maintenance (O&M) costs, capital costs, and replacement costs are investigated. The well-recognized simulation tool, HOMER (Hybrid Optimization of Multiple Energy Resources) developed by the National Renewable Energy Laboratory, is used to fulfill this study. The sensitivity investigation is carried out by optimally scaling the configuration capacities as well as by monitoring the future changes like weather, load demand, and fuel price uncertainties. The results of the sensitivity investigation and HOMER simulation confirm that the wind/DG/FC/battery hybrid off-grid configuration is the most economic and eco-friendly solution with a total GPC of 7.045 million USD, COE of 0.271 USD/kWh, and CO2 emissions of 566 tons. This signifies the 13.84% reduction of net present cost compared to DG-based units, with a 64.2% decrease of pollutants and zero unmet load.

The main purpose of this work is to examine the techno-economics and environmental assessment of the Solid Recovered Fuel and Lignite to methanol pathway. Methanol is produced by gasifying the solid fuels to carbon monoxide and hydrogen and then reacting to produce methanol under pressure during the methanol synthesis process. The data obtained from the partners is used to adapt this study for the liquid fuel synthesis application. The in-house personal computer-based process simulation package, ECLIPSE, is used to perform process modelling and the techno-economic assessment of methanol production. The @Risk 8.2© software is used to estimate the cost contingency of the project. The SimaPro© software package was used to carry out the Life Cycle Assessment (LCA). The gasifier plant contributes significantly to the capital costs. The results show that increased Solid Recovered Fuel (SRF) in the feedstock mix has favourable economics due to the negative SRF charges resulting in a lower break-even selling price (BESP) than feedstock mixes with higher ratios of Lignite. Plant availability, capital investment and the time value of money are the factors that have the greatest impact on BESP. Increasing the SRF in the feedstock mix decreases the Global Warming impact of the methanol production compared to higher proportions of Lignite. However, the resultant impact is much greater than that of a natural gas reformer. Furthermore, the employment of off-gas recovery and carbon capture can further reduce both the Global Warming impact and the overall Single Score of the process, making it favourably comparable to the natural gas water gas shift configurations. Graphical abstract

Sugarcane bagasse (SCB) is a significant agricultural residue generated by sugar mills based on sugarcane crop. Valorizing carbohydrate-rich SCB provides an opportunity to improve the profitability of sugar mills with simultaneous production of value-added chemicals, such as 2,3-butanediol (BDO). BDO is a prospective platform chemical with multitude of applications and huge derivative potential. This work presents the techno-economic and profitability analysis for fermentative production of BDO utilizing 96 MT of SCB per day. The study considers plant operation in five scenarios representing the biorefinery annexed to a sugar mill, centralized and decentralized units, and conversion of only xylose or total carbohydrates of SCB. Based on the analysis, the net unit production cost of BDO in the different scenarios ranged from 1.13 to 2.28 US$/kg, while the minimum selling price varied from 1.86 to 3.99 US$/kg. Use of the hemicellulose fraction alone was shown to result in an economically viable plant; however, this was dependent on the condition that the plant would be annexed to a sugar mill which could supply utilities and the feedstock free of cost. A standalone facility where the feedstock and utilities were procured was predicted to be economically feasible with a net present value of about 72 million US$, when both hemicellulose and cellulose fractions of SCB were utilized for BDO production. Sensitivity analysis was also conducted to highlight some key parameters affecting plant economics.

Techno-economic analysis is a core methodology for assessing the feasibility of new technologies and processes. The outcome of an analysis is largely dictated by the product’s price, as selected by the practitioner. Representative future price distributions are required as inputs to investment, sensitivity, and uncertainty analyses across the 20 to 25 year plant life. However, current price selection procedures are open to subjective judgment, not adequately considered, or neglected by calculating a minimum selling price. This work presents a machine learning methodology to produce unbiased projections of future price distributions for use in a techno-economic analysis. The method uses an ensemble of 100 neural network models with Long Short-Term Memory layers. The models are trained on the Energy Information Administration’s (EIA) long-term crude oil projections and a commodity’s historic price data. The proposed method is demonstrated by projecting the price of five commodity chemicals 26 years into the future using 12 years of historic data. Alongside the economic outlook extracted from the EIA projections, the five commodity price distributions capture stochastic and deterministic elements specific to each commodity. A statistically significant difference was observed when using the price projections to revise the Net Present Value distributions for two previous techno-economic analyses. This suggests that relying on heuristics when selecting price ranges and distributions is unrepresentative of a commodity’s price uncertainty. The novelty of this work is the presentation of an unbiased machine learning approach to project long-term probabilistic prices for techno-economic analyses, emphasising the pitfalls of less rigorous approaches.

Due to an overburdened national grid, chronic energy challenges, and the growing municipal solid waste menace, a unique opportunity to deploy waste-to-energy technology in Ghana is apparent. A techno-economic analysis was performed for meeting the primary electrical load of selected blocks at the University of Energy and Natural Resources through Municipal Solid Waste gasification. Three scenarios were simulated and assessed based on their Net Present Costs (NPC) and Levelised Cost of Energy (LCOE): a gasifier-standalone system, a grid-tied gasifier system and a grid-alone system. The grid-tied gasifier system was found to meet the 230.1kWh/day electrical load at the least NPC ($2, 049790.00) and COE ($0.09426/kWh). The sensitivity analysis showed that the load factor, sell-back price of electricity and cost/ton of MSW had the most impact on the NPC of the gasification system. MSW gasification is, therefore, an economically viable alternative if grid-integrated. Finally, the study showed that Feed-in Tariffs, plant siting and demand response strategies are crucial to ensuring the cost-effectiveness of gasification systems.

Present study investigates techno-economic feasibility of trimellitic acid (TMLA) production from a biorenewable precursor 5-hydroxymethyl furfural (HMF) for the first time . A 5 kmol/hr HMF feed rate to produce 99% pure TMLA is considered to provide a roadmap for fixing the minimum sales price of TMLA for significant return on investments and a shorter payback period. The current TMLA sales price varies significantly ($10/kg-$1000/kg) in different markets; depending on the process for TMLA production. Thus, techno-economic feasibility study for TMLA production is investigated considering variable sales price . It is also observed that two distinct reaction routes for TMLA production from HMF are possible and both routes can be profitable even at the minimum sales price of $10/kg. Nevertheless, TMLA production from direct conversion of HMF in one step showed better IRR (105.94%) than IRR (39.42%) calculated for a two-step process. It is also observed that catalyst and raw materials costs are main contributing factor in capital and operating costs, respectively. Thus, cost of feed is varied to study the possible future cases, as HMF cost may decrease in the future with advances in the development of biomass conversion technologies. It is observed that the IRR of the TMLA production plant would further increase significantly by ∼16% if raw material cost is reduced by 10-40% in the future.

Renewable cooling via absorption chillers being supplied by various green heat technologies such as solar collectors has been widely studied in the literature, but it is still challenging to get positive economic outcomes from such systems due to the large expenses of solar thermal systems. This study offers the use of a new generation of solar collectors, so-called eccentric reflective solar collectors, for driving single-effect absorption chillers and thereby reducing the levelized cost of cooling. This article develops the most optimal design of this system (based on several different scenarios) using multi-objective optimization techniques and employs them for a case study in Brazil to assess its proficiency compared to conventional solar-driven cooling methods. For making the benchmarking analyses fair, the conventional system is also rigorously optimized in terms of design and operation features. The results show that the eccentric solar collector would enhance the cost-effectiveness by 29%. In addition, using optimally sized storage units would be necessary to get acceptable economic performance from the system, no matter which collector type is used. For the case study, at the optimal sizing and operating conditions, the levelized cost of cooling will be 124 USD/MWh and an emission level of 18.97 kgCO2/MWh.

The European Union guides its member states to a gradual uptake of sustainable aviation fuel (SAF) from 2% vol. in 2025 to 63% vol. by 2050 with the ReFuelEU proposal as part of the Fit-for-55 package. A promising production pathway for SAF presents itself in the Power Biomass to Liquid (PBtL) process, which converts non-crop-based biomass residue and renewable power via the Fischer–Tropsch route. In this study, a techno-economic and greenhouse gas (GHG) emission analysis of a small-scale (50 MWth) PBtL process concept, developed in the EU project FLEXCHX, is presented. The analysis is conducted with a thermodynamic process model implemented in Aspen Plus®, which relies on experimental project data. For the PBtL base case production costs of 1.09 €2020/l are estimated, whereby electricity and investment into the alkaline electrolyzer constitute the largest cost drivers. At low electricity prices (2 recycling is only economically reasonable below an electricity price threshold, which is found at 20 €/MWh for the base case. Further, PBtL is heavily dependent upon the availability of low GHG electricity in order to produce SAF with a low carbon footprint. Assuming full utilization of the EU’s non-crop-based biomass residues, the EU jet fuel demand for 2030 could be met with the PBtL process.

This work compares with a two-step procedure the performance of different Heat Transfer Fluids (HTF) for high temperature receiver applications (up to 715 °C) in advanced Solar Tower (ST) plants. The most promising molten salts and liquid metals are initially selected and ranked according to their performance, estimated with different Figures of Merit (FoM) available in literature or newly defined. For the best performing fluids, different hydraulic configurations and tube diameters at fixed receiver size are tested. The optimized external tubular receiver configuration for each HTF is then implemented in a ST plant and its performance is assessed through a detailed techno-economic analysis, considering the use of a direct thermal energy storage system and of a sCO2 based power cycle. As a second step, the yearly electricity yield and the LCOE are evaluated for two different sites. Results show NaCl–MgCl2 as the best option for the considered type of plant with a LCOE of 151 $/MWh, which is anyhow 10% higher than the reference Solar Salts case.

The resultant residues after thermal processes can be reused in the form of activated carbon (AC) production or used for soil amelioration. However, the economic and energy optimisation of the waste revaluation process is necessary for the prediction of technology requirements, investment boundaries and cost-benefit analysis. Mass, energy and cost estimation of the entire process were systematically executed relative to equipment sizing and type of product, as major factors in the evaluation. The economic analysis and process optimisation were quantified and evaluated with the Aspen Plus economy and an SPSS statistical tool for economic analysis. Simulation results were concomitant with economic analysis to determine the approximate annualised return on investment, profitability index and payback period, using optimised variables in the process. The four processes examined: process scenario 1-4 (pyrolysis, gasification, combustion and combined) have 16, 17, 14 and 17.2% return on investment for the 8.5, 8.2, 9.8 and 8-year payback period, respectively. The results provide a technology assessment and economic guide for investors and policymakers among others. This work is also useful for researchers in achieving the goal of efficient biomass utilisation. Palm waste ash as a potential alternative to chemical fertiliser, especially for the treatment of ultisol and acidic soils, were evaluated and it was confirmed that it is a good alternative to typical inorganic fertiliser. Finally, the results indicate that using such wastes in the AC market is a viable business option, though with high initial capital investment even though palm waste ash can be produced locally.

This paper reports the results obtained in a techno-economic analysis of the Steam Methane Reforming (SMR) technology aided with solar heat, developed and demonstrated in the European FCH JU project CoMETHy: a compact membrane reformer heated with molten salt up to 550 °C allowed to simultaneously carry out methane steam reforming, water-gas-shift reaction and hydrogen separation. This reactor can be integrated with new generation Concentrating Solar Thermal (CST) systems to supply the process heat. Experimental validation of the technology has been successfully achieved in a pilot scale plant and the results recently published. In this paper, we introduce a fully-integrated scheme and operation strategies of a plant on the 1500 Nm3/h hydrogen production scale. Then, techno-economic analysis of this new solar-driven process is presented to evaluate its competitiveness. Considering a plant capacity of 1500 Nm3/h (pure hydrogen production) and today's costs for the methane feed and the CST technology, obtained Hydrogen Production Cost (HPC) are in the range of 2.8–3.3 €/kg for a “solar-hybrid” system with high capacity factor (8000 h/year operation) and 4.7 €/kg for a “solar-only” case, while HPC≅1.7 €/kg can be obtained with the conventional route under equivalent assumptions. However, a sensitivity analysis shows that the expected drop of the cost of the CST technology will bring the HPC around 2.4 €/kg for the “solar-hybrid” case and close to 3.4 €/kg for the “solar-only” case, thus making the cost of solar reforming closer to conventional SMR with CO2 capture and with wind/solar electrolysis in the future. In the “solar-hybrid” case total CO2 production can be reduced by 13–29% with 58–70% of produced CO2 recovered as pure stream (at 1.3 bar); in the “solar-only” case total CO2 production can be reduced by 52% and 100% of produced CO2 recovered as pure stream (at 1.3 bar). However, compared to the conventional route, CO2 avoidance costs are still relatively high (≥137 €/tonCO2) and process optimization measures required. Therefore, optimization measures have been outlined to increase the overall process efficiency and further reduce the HPC.

This study assessed the environmental impacts and economic feasibility of generating heat using wood-briquettes (WBs), and heat and electricity using torrefied-wood-briquettes (TWBs). WBs and TWBs were manufactured from forest residues using portable systems and delivered to either residential consumers or power plants in the United States. An integrated cradle-to-grave life-cycle assessment (LCA) and techno-economic analysis (TEA) approach was used to quantify environmental impacts and minimum-selling prices (MSPs) of heat and electricity, respectively. Results illustrated that 82% and 59% of the cradle-to-grave global warming (GW) impact of producing heat resulted from the feedstock preparation in WBs and torrefaction in TWBs, respectively. About 46–54% of total cost in the production of heat were from labor and capital costs only. The GW impact of electricity production with TWBs was dominated by the torrefaction process (48% contribution). Capital cost (50%) was a major contributor to the total cost of electricity production using TWBs. The GW impacts of producing heat were 7–37 gCO₂eq/MJ for WBs, and 14–51 gCO₂eq/MJ for TWBs, whereas producing electricity using TWBs was 146–443 gCO₂eq/kWhe. MSPs of generating heat from WBs and TWBs were €1.09–€1.73 and €1.60–€2.26/MJ, respectively, whereas the MSP of electricity from TWBs was €20–€25/kWhe. Considering carbon and pile-burn credits, MSPs of heat and electricity were reduced by 60–90% compared to the base-case.

In this paper, we present a techno-economic analysis of providing a Cooperative, Connected and Automated Mobility (CCAM) use case, namely Cooperative Lane Merging (CLM), in a cross-border environment. Multiple network deployment scenarios are proposed to provide Vehicle to Infrastructure (V2I) connectivity with respect to PC5 Mode 4 – enabled RSUs. Total cost of Ownership (TCO) model together with four revenue models are developed to assess the viability of providing CCAM services in the studied settings. Results show that the higher the number of simultaneous connected cars, the higher the TCO of the required deployment needs to be to meet the defined KPIs and especially for the green field deployment with no existing fibre cable or electricity facilities. Another important insight from this analysis is that only with a high fleet penetration rate of connected vehicles, a viable business case can be achieved.

This work compares three postcombustion CO2 capture processes based on mature technologies for CO2 separation, namely, (i) absorption using an aqueous piperazine solution, (ii) adsorption using Zeolite 13X in conventional fixed beds (either vacuum swing adsorption or temperature swing adsorption), and (iii) multistage membrane separation using a polymeric material (with CO2/N2 selectivity of 50 and permeability for CO2 of 1700 GPU). All three capture plants are assumed to be retrofitted to a generic industrial CO2-emitting source with 12% CO2 v/v (with 95% relative humidity at the inlet temperature and pressure of 30 °C and 1.3 bar, respectively) to deliver CO2 at 96% purity. In the cases of adsorption and membranes, the flue gas is dried before feeding it to the CO2 capture unit. In a first step, the capture processes (i.e., components and design parameters) are optimized based on their technical performance, defined through process exergy requirement and plant productivity; exergy–productivity Pareto fronts are computed for varying CO2 recovery rates. Second, the economic performance of the processes is assessed through a cost analysis. Estimates of CO2 capture costs are provided for each process as a function of the plant size and CO2 recovery rate. The comparative assessment shows that, although the adsorption- and membrane-based processes analyzed may become cost competitive at the small scale (i.e., below sizes of 100 tons of flue gas processed per day) and low recovery rates (i.e., below ca. 40%), the absorption-based process considered is the most cost-effective option at most plant sizes and recovery rates., ACS Engineering Au, 1 (1), ISSN:2694-2488

At present, the synthesis of ammonia through the Haber-Bosch (HB) process accounts for 1.2% of the global carbon emissions, representing roughly one-fourth of the global fossil consumption from the chemical industry, which creates a pressing need for alternative low-carbon synthesis routes. Analyzing seven essential planetary boundaries (PBs) for the safe operation of our planet, we find that the standard HB process is unsustainable as it vastly transgresses the climate change PB. In order to identify more responsible strategies from this integrated perspective, we assess the absolute sustainability level of 34 alternative routes where hydrogen (H-2) is supplied by steam methane reforming with carbon capture and storage, biomass gasification, or water electrolysis powered by various energy sources. We found that some of these scenarios could substantially reduce the global impact of fossil HB, yet alleviating the impact on climate change could critically exacerbate the impacts on other Earth-system processes. Furthermore, we identify that reducing the cost of electrolytic H-2 is the main avenue toward the economic appeal of the most sustainable routes. Our work highlights the need to embrace global impacts beyond climate change in the assessment of decarbonization routes of fossil chemicals. This approach enabled us to identify more suitable alternatives and associated challenges toward environmental and economically attractive ammonia synthesis., ACS Sustainable Chemistry & Engineering, 9 (29), ISSN:2168-0485

18 figures, 8 tables.-- © 2023. This manuscript version is made available under the CC-BY-NC-ND 4.0 license https://creativecommons.org/licenses/by-nc-nd/4.0/, The development of sustainable and renewable energy technologies has received significant attention to realize Net-Zero CO2 equivalent emission goals and meet the growing energy demand. Hydrogen is a promising energy carrier that can facilitate the large-scale deployment of renewable energy sources and assist in the replacement of fossil fuels and to reduce the impact of global warming. The objective of this research is to present an advanced hydrogen-integrated renewable energy system model to meet the energy demand of a distributed community and produce green hydrogen from excess/curtailed renewable energy. The study employs an anion exchange membrane water electrolyzer (AEM) for producing hydrogen. An optimization model of the renewable energy system and a mathematical model of the electrolyzer are developed to achieve this objective. The model uses an energy maximisation approach and optimally combines wind system, biogas plant, and solar PV system to meet the residential and commercial load demands. To increase the system stability, the model is interconnected with the local grid station for energy exchange. Moreover, an uncertainty analysis is also performed to analyse the system response under random variation in load demand. The study results show that a significant amount of clean energy (15,025 MWh/year) is produced by the system at the lowest levelized cost of 0.084 €/kWh and a reduction of 6,078 tons of CO2 emission during the first year of operation is obtained. The electrolyzer produces 63 kg/hr of hydrogen, while the cell performance remains stable at 60 °C and the cell voltage reaches 2.019 V at 2.415 A/cm2 current density., Sincere gratitude and special thanks to the Department of Mechanical Engineering at Northern Illinois University, and the Biomass Research Center, CIRIAF and the University of Perugia for providing the facilities and support to conduct this research work.

Power-to-X (PtX) is a large-scale, long-term energy storage approach for converting renewable electrical energy into various chemical fuels. Unlike conventional fossil fuel production processes that operate continuously, PtX processes encounter operational challenges due to fluctuations in renewable power supply. To improve the operational flexibility of PtX processes for industrial applications, it is crucial to develop systematic strategies that can adapt to these fluctuations, which will increase PtX's energy and cost efficiencies. This study comprehensively explores various strategies for flexible operation of renewable-powered PtX processes, which include the use of additional energy buffers and grid connections. Power and material allocation models are developed for PtX processes based on islanded; grid-assisted; and grid-assisted, bidirectional connections by using three possible energy buffers (i.e., hydrogen intermediate storage, Li-ion batteries, and Carnot batteries). Surrogate model-based optimization is performed to establish an economically optimal design for each case. A power-to-methanol process implemented in Kramer Junction, California is studied to investigate the effects of flexible operation strategies on process performance in terms of production cost, renewable penetration, and energy efficiency. The findings of this study offer new insights into the operational flexibility of PtX processes and provide general recommendations for improving the flexibility and performance of PtX, particularly with respect to the establishment of a grid connection and the selection of an appropriate energy buffer.

Optimal planning of hybrid energy systems has always been a considerable task. While several studies have conducted techno‐economic analysis on hybrid energy systems, most of them have neglected to consider appropriate electric and thermal load growth rates. This paper proposes an efficient strategy for optimizing a grid‐connected hybrid energy system considering electric and thermal load growth rates. HOMER software is used for optimizing hybrid energy systems. It uses a nonderivative optimization to recognize the system with the minimum net present cost (NPC) among hundreds of configurations. The exponential smoothing method is also used for predicting upcoming load peak values based on historical data. The proposed hybrid system includes solar photovoltaic (SPV) system, wind turbine (WT) system, converter, battery storage system (BSS), gas generator (GasGen), fuel cell (FC), fuel‐fired boiler, and resistive boiler. Unlike previous studies, electricity price growth and SPV degradation rates are considered in this study. The grid‐connected system has also been compared to the stand‐alone system to understand grid connection impacts on the optimization results. Environmental analysis has been performed to analyze the greenhouse gas emissions of each system. The effects of growth rates in thermal and electric loads and electricity price are comprehensively investigated. Neglecting load growth rates affected the financial results severely. In this condition, the NPC and COE are achieved −11 383.4 US$ and −0.02376 US$/kWh. Results indicate that the combination of WT system (15 kW), converter (10 kW), resistive, and fuel‐fired (10 kW) boilers is the most economical configuration in grid‐connected mode. The WT system plays an essential role in the electric power provision and revenues of the hybrid system. The net present cost (NPC) and the cost of energy (COE) for grid‐connected operating mode are achieved −0.0162272 US$/kWh and −5243.956 US$, respectively. For off‐grid operating mode, the NPC and COE are obtained 47 024.19 US$ and 0.1983879 US$/kWh, respectively. Thanks to the feed‐in‐tariff (FiT) policy, the proposed grid‐connected system is more economical and environmentally friendly than the stand‐alone system. In off‐grid operating mode, 63 575.45285 kg CO2 is produced, which is higher than CO2 production in the grid‐connected mode (more than 8262 kg).

H2 production from solar electricity in the region of the Atacama Desert – Chile – has been identified as strategical for global hydrogen exportation. In this study the full supply chain of solar hydrogen has been investigated for 2018 and projected to scenarios for 2025-2030. Multi-year hourly electrical profiles data have been used from real operating PV plants and simulated Concentrated Solar Power “CSP” plants with Thermal Energy Storage “TES” as well as commercial electricity Power Purchase Agreement “PPA” prices reported in the Chilean electricity market were considered. The Levelized Cost of Hydrogen “LCOH” of each production pathway is calculated by a case-sensitive techno-economic MATLAB/Simulink model for utility scale (multi-MW) alkaline and PEM electrolyser technologies. Successively, different distribution, storage and transportation configurations are evaluated based on the 2025 Japanese case study according to the declared H2 demand. Transport in the form of liquefied hydrogen (LH2) and via ammonia (NH3) carrier is compared from the port of Antofagasta, CL to the port of Osaka, JP. QC 20220808

The EU Horizon2020 consortium PHOTOFUEL joined academic and industrial partners from biology, chemistry, engineering, engine design, and lifecycle assessment, making tremendous progress towards engine-ready fuels from CO2 via engineered photosynthetic microbes. Technical, environmental, economic, and societal opportunities and challenges were explored to frame future technology realization at scale. Copyright © 2021 Elsevier Ltd. All rights reserved.

Conference contribution to ECOS 2019. This paper uses a real options framework that incorporates the option to postpone an investment to reduce market uncertainties and wait for technology learning to occur. The focus is to investigate how the usage of an investment decision rule based on real options analysis affects technology choice, the economic performance, and when in time it is favourable to invest in pulp mill integrated biofuel production, compared with using a decision rule based on traditional discounted cash flow analysis. As an illustrative case study we examine a pulp mill which has the option, but not the obligation, to invest in either of two different biofuel production technologies that both use the pulp mill by-product black liquor as feedstock: (1) black liquor gasification followed by fuel synthesis, and (2) membrane separation of lignin followed by hydrodeoxygenation.

1,3-butadiene (butadiene) is a by-product produced during naphtha steam cracking, predominantly used in tyre manufacturing. Recently, steam crackers have converted to using more cost effective, lighter feedstocks such as shale gas, yielding less butadiene. The potential shortfall, coupled with concerns around increasing greenhouse gas emissions, provides a unique opportunity for renewable production. This study investigated the techno-economics and greenhouse gas emissions associated with renewable butadiene production routes within the context of a China located pulp mill. A hybrid bio-catalytic route, utilising black liquor, was compared against two chemo-catalytic routes using forestry residues and pulpwood. The hybrid bio-catalytic route uses a novel aerobic gas fermentation platform, employing heat integrated supercritical water gasification and aerobic gas fermentation to produce acetaldehyde, followed by chemo-catalytic upgrading (Acet-BD). The two chemo-catalytic routes catalytically upgrade biomass derived syngas; where one route (Eth-BD) passes through an ethanol intermediate, and the other (Syn-BD) utilises a series of commercialised catalytic technologies with propene as an intermediate. The hybrid bio/chemo-catalytic route, Acet-BD, was the only route profitable using the nominal techno-economic inputs, producing a Net Present Value of $2.8 million and Minimum Selling Price of $1367 tn−1. In contrast, the two chemo-catalytic routes produced Minimum Selling Prices of $1954 tn−1 (Eth-BD) and $2196 tn−1 (Syn-BD), demonstrating the competitiveness of this novel platform. Sensitivity analyses highlighted the equipment capital as the main contributor to increased Minimum Selling Price for all cases, and the Acet-BD route presented a 19% probability of achieving a positive net present value. Moreover, owed to the low process emissions and sequestration of biogenic carbon, all routes produced net negative emissions within a cradle-to-gate framework. As such, renewable butadiene production has potential as a net carbon sink for pulp mill residues conventionally destined for energy recovery.

The mooring system plays a key role in a floating offshore wind turbine: it connects the floating structure to its anchor on the seabed and it is designed to prevent the platform from drifting under the action of wind, waves and currents. The layout of the mooring system is strictly connected to the installation site: in the first place it depends on the bathymetry and the type of seabed which conditions the type of anchor that can be used; secondly by the wind and waves loads in extreme sea states. To properly design the mooring system, three different configurations are proposed and discussed, respectively adapting catenary, taut leg and semi-taut methodologies for a floating offshore wind turbine located near the island of Pantelleria, in Sicily. For each configuration, the Hexafloat foundation, developed by Saipem, is considered. Important design constraints such as how large the nominal sizes are, how long the mooring lines are, how far the anchor points are located, are demonstrated in detail. The material used will range from steel chains and wires to polyester ropes, to grant economically viable solutions.

Net-metering has been introduced as an alternative to the feed-in tariff scheme to encourage consumers to act as prosumers by installing photovoltaics. Originally, net-metering referred mainly to household photovoltaic systems, however, larger prosumers connected to medium-voltage networks are also considered. Scope of this paper is to present a techno-economic assessment methodology to evaluate the viability of net-metering policy in medium-voltage prosumers. Unlike most relevant methods, the proposed methodology combines techno-economic analysis with a quasi-static simulation model incorporating the real-world operational properties of the distribution network, where the medium-voltage prosumers are connected. The analysis focuses on nine university campuses operating under net-metering policy. The impact of several important parameters on the viability of the investment as well as on the optimal size of the system is investigated; among them special emphasis is given on the applicability of the decentralized voltage regulation techniques applied to the prosumer's photovoltaic system.

Standalone rural microgrid (MG) systems are considered as a sustainable and economical solutions towards rural area electrifications. Specific control schemes are necessary to adopt for reliable and economic performance of these rural MGs. This study focuses on the optimal utilization of biomass potential considering specific applications of bio generator (BG) with BG-PV-WT-BSS and BG-PV-SMES based standalone rural MG systems. In the first case of the BG-PV-WT-BSS, the optimal sizing/selection of DGs of a rural MG has been proposed using the improved-MILP (I-MILP) approach. The objectives of this study were to minimize total net present cost (TNPC), the levelized cost of energy (LCOE) and GHG emissions. In the second case of BG-PV-SMES, the simulation model of the rural microgrid consisting of a variable speed bio generator (VSBG) and photovoltaic (PV) has been developed. Afterwards, a simplified EMS has been designed for the coordinated operation control of the distributed energy resources (DERs) in the rural MGs using MATLAB/Simulink® environment. For the DGs connected via power converter, FOSMC and FCS-MPC based coordinated control has been proposed in the simplified EMS. The purpose of the FOSMC and FCS-MPC based power converter is the improvement of the system performance (for instance power quality, regulated voltage and THD) under external disturbances. Simulation analysis shows the better operation of FOSMC and FCS-MPC under less THD and improved power quality.

This work designed, modeled and performed economic analysis of the base case extraction and recovery of catechin mix (CM) from Camellia sinensis leaves (CSL) using deep eutectic solvent (DES) and microwave assisted extraction (MAE) with the assistance of SuperPro Designer software. Techno-economic analysis of three commercial scales of manufacture was also investigated and compared using profitability parameters. Sensitivity and uncertainty analyses were further carried out on the most viable commercial scale to determine input variable (s) of highest significance on the profitability of the process. The 3.30 kg CM/batch is the most economically desirable scale with return on investment of 324.65%, payback period of 0.31 year, internal rate of return of 163.83% and net present value of 1,059,595,224. Out of the input variables selected for the sensitivity and uncertainty analyses, CSL and DES costs have the least effect on the selected profitability parameters of the process.

Industrial facilities release a large amount of heat as a by-product of their processes. To improve environmental performance and increase process profitability, a portion of the waste heat can be recovered and employed for power generation by recovery systems. Supercritical carbon dioxide (sCO2) plants are emerging as potential alternatives to the well-established technologies for waste heat recovery (WHR) power generation in heavy industry. This paper offers a preliminary techno-economic analysis of a waste heat-to-power system based on a sCO2 closed-loop for a heavy-industrial process. By conducting a parametric investigation on the WHR sCO2 system’s key design parameters, a number of preferable configurations from a thermodynamic perspective were initially identified; they were subsequently analyzed from the economic point of view in terms of net present value (NPV) and pay-back period (PBP). The privileged WHR system configuration achieved an overall efficiency of 30.4% and a power output of 21.6 kWe, providing an NPV of almost US k$ 376 with a PBP of approximately 4.5 years.

Libya is currently interested in utilizing renewable energy technologies to reduce the energy dependence on oil reserves and Greenhouse Gas (GHG) emissions. The objective of this study is to investigate the feasibility of a 10MW grid-connected PV power plant in Libya. NASA data are used to analyze the global horizontal irradiation, direct normal irradiation, and air temperature of 22 selected locations in Libya and to evaluate the potential of solar energy. RETScreen software is used to estimate the energy production, GHG emissions, and financial parameters for the 22 locations. Based on the solar atlas map, it is noticed that the highest global horizontal irradiation is in the southern part of Libya, which ranged from 2100 to 2500kWh/m2. These results indicate that Libya has a huge solar energy potential that can be used to ‎generate electricity. Moreover, based on techno-economic results, it is observed that the highest electricity generation of 22067.13MWh is recorded at Al Κufrah and the lowest at Al Jabal al Akhdar with a value of 17891.38MWh. Furthermore, Al Kufrah and Murzuq are the best locations for the future installation of PV power plants from annual energy and the economic parameters point of view. The maximum value of power that can be generated by the plant was estimated to be 22.06GW.

Several edible and non-edible oil sources are currently being developed as renewable basestocks for biolubricant production. However, these feedstocks possess undesirable physicochemical properties limiting their lubricant applications. Chemical modification and additive-based routes could be used to modify their properties -suitable for different biolubricant applications. The first part of this study compares how the selected modifications affect the properties of the basestocks. Next, the techno-economic analysis (TEA) was conducted to study 4 selected biolubricants and a potential biolubricant derived from marine microalgae biomass. Oxidative stabilities of chemically modified biolubricants followed the order of epoxidation> triesterification> estolide. Pour points of triesters showed minimal increments and reduced for estolides, whereas epoxidation increased pour points. Estolides exhibit maximum kinematic viscosity increment among chemical modification routes, followed by TMP-transesterification and epoxidation. The oxidative stability of chemically modified biolubricants was higher than additized biolubricants; conversely, the viscosity increments and pour point reductions for additized biolubricants were higher than chemically modified biolubricants. TEA results show that the unit cost for producing 1-kg estolide was the highest among the chemical modification routes. The unit cost per kilogram of jatropha biolubricant produced using the additive-based route was lower than chemically modified biolubricants. Due to a high microalgal oil feedstock cost, the unit cost per kilogram of additized microalgae oil biolubricant was more than the unit cost of additized Jatropha oil. The techno-economic feasibility of biolubricant production from marine microalgal oil could be improved by adopting a biorefinery approach. 2022 The authors would like to acknowledge the support of the Qatar National Research Fund (QNRF, a member of Qatar Foundation) for providing the funding (under grants UREP26-080-2-021 , MME01-0910-190028 ), and grant QUEX-QFQAQU-18/19-IDC ) for this study. Scopus

The momentous deployment of photovoltaic (PV) installations in modern times converted schemes utilised to support behind-the-meter systems to compensation mechanisms promoting self-consumption for all prosumer types. Moreover, their incorporation with battery storage systems (BSS) is expected to remove technical counter effects and assist in more self-sufficient prosumer sites. As electricity prices are continuously rising, negatively impacting consumers, we intend for this study to serve as a guideline for residential PV-BSS sizing. Additionally, its objective is to provide an operational and economic evaluation of PV-BSS by considering relevant schemes and concentrating on the most effective parameters. This study contributes to the literature with a holistic methodology for sizing and techno-economically evaluating residential systems in the Mediterranean area that is replicable for any state or consumption class. Simulations addressing PV-BSS performance were exploited with the use of real (high-resolution) data, estimating particular sizing, operational, and techno-economic indicators during the entire system lifetime within the framework of a techno-economic analysis. The simulations calculated the initial expenditure, the yearly revenues from the PV-BSS operation, and the corresponding expenses, contrasting them on a year-to-year basis. The results demonstrate that for the five countries addressed as case studies, PV-BSS sizing is significantly impacted by the supporting scheme regarding maximum financial gains. A likeness amid the ideal power-to-energy ratio (PER) indicator of every addressed state for the examined parameters (electricity price and consumption class) was demonstrated for the full self-consumption scheme, whereas for net billing, intercountry discrepancies and generally higher optimal PER values were observed. Finally, an increase in electricity prices or consumption generally decreases optimal PER; therefore, a recommendation is provided for the avoidance of inessential expenditures in surplus system component sizes.

Project SMART (Strategies to Promote Small-Scale Hydro Electricity Production in Europe) from the Intelligent Energy Europe (IEE) program, in which 7 institutions from 5 European states participate, pointed to the important barriers for the expansion of small hydro power plants (SHP) in Europe. One of the main barriers is the lack of suitable methodology and software able to create a clear view of the SHP potential in the given territory, as well as a complete techno-economic analysis for certain locations. Worldwide, there are a certain number of software for this purpose, and will be presented in this paper. However, in practical application for concrete cases, they show certain disadvantages. For example, one software is not able to take into account all the specifics of watercourses and plants; another does not have the option of selecting all types of turbines; in others, the calculation models are based on a limited number of equations that do not describe all possible cases; in some, economic analysis is oversimplified, etc. The aim of this paper is to develop software that is more comprehensive than any existing software. A new software for the techno-economic analysis of SHP is developed using Python and will be presented in this paper. The software is very useful for experts in the field of SHP, but also much wider, for decision-makers, potential investors, and stakeholders, especially in developing countries. It will improve water resources management, disseminate opportunities to investors, and increase the interest of stakeholders to invest in SHP, resulting in their wider use. The software is tested on location for SHP in the Republic of Croatia by comparison with the results obtained by the usual classical calculation. The agreement of the results is satisfactory.

This manuscript describes the conceptual process design of an integrated xylitol biorefinery with value-added co-products. Based on an existing three-step framework, the main product of a second-generation integrated biorefinery is chosen in the first stage. Based upon this, other decisions as the feedstock and value-added co-products are made. All relevant unit operations for the process are introduced. An initial superstructure with all potential process alternatives is composed of all introduced models. In the second step of the framework, a global sensitivity analysis is performed, firstly with coarse sampling to determine all viable flowsheet options and secondly with fine sampling to determine the most sensitive operational variables. As a result of the sensitivity analysis, most of the flowsheet options in the initial superstructure are not feasible. Based on these results, flowsheet sampling with the five most sensitive operational variables is performed to create surrogate models. In the scope of this work, three types of surrogate models are benchmarked against each other. Regarding the results of the superstructure optimization, firstly, it becomes apparent that the production of biokerosene does not contribute significantly to the net present value of the biorefinery. Furthermore, reducing the number of unit operations in the downstream processing leads to lower capital expenditures, but it lowers the product yield. Lastly, most flowsheets are economically feasible, indicated by a positive net present value. Based on this result, the most promising candidate process topology is subjected to the third step of the framework, including uncertainty in capital expenditure and operational expenses according to their estimations and uncertainties in the product prices. As a result, the net present value of the flowsheet turns negative, indicating that the high uncertainties for the expenditure and the expenses do not allow for an economically feasible operation. Lastly, the analysis of conceptually designed process flowsheets based on Monte Carlo sampling shows failure rates, with the NPV falling below the break-even point, of around 60% probability or higher. Based on these results, an economically feasible construction and operation of a xylitol biorefinery seems unlikely. Further ways to improve the metrics are elucidated.

Volatile methyl siloxanes (VMS) are persistent contaminants extensively used in industrial applications. Their presence in biogas constitutes a major hindrance for its energetic valorization or its use as renewable natural gas. Current commercial siloxanes abatement technologies are based on physical-chemical methods, whose good performance is impaired by their high investment costs, and a hefty environmental impact. Research evidences that VMS are indeed biodegradable, which opens the possibility of implementing bio-based technologies as a cost-effective and sustainable alternative for the removal of these compounds. This review uncovers the most plausible organisms and microbial pathways involved in biological VMS degradation, a relatively unexplored area. Additionally, the most commonly applied configurations and the main operating challenges are thoroughly revised and discussed, evidencing that a feasible implementation relies on the optimization and scale-up of enhanced mass transfer bioreactors. Finally, the techno-economic and environmental analysis demonstrate that, although in a very early stage, emerging biological technologies for siloxanes removal will play an important key role on the future abatement of VMS from waste gas streams such as raw biogas.

RESUMEN: Este Trabajo Fin de Máster se enmarca en una de las actividades del proyecto europeo Energy Push SOE3/P3/E0865 sobre eficiencia energética en viviendas sociales en el que participa la Universidad de Cantabria. El proyecto implementará en Cantabria un sistema híbrido de energías renovables con tecnologías de hidrógeno para el suministro autosuficiente de energía a una vivienda social en la localidad de Novales (Cantabria). En este contexto, el objetivo del presente TFM será el de evaluar diferentes configuraciones y tecnologías empleando el software de optimización HOMER Pro que tiene en cuenta aspectos climatológicos de las diferentes localizaciones, así como aspectos económicos de los elementos tecnológicos considerados. Como resultado se obtendrán las dimensiones de las configuraciones óptimas en términos económicos y técnicos que permitan llevar a cabo esta implementación con el menor coste de inversión posible. En el presente proyecto también se realizará el mismo análisis para otras localidades analizadas en el proyecto en Francia y Portugal. Máster en Ingeniería Industrial

Scalable, low-cost biofuel and biochemical production can accelerate progress on the path to a more circular carbon economy and reduced dependence on crude oil. Rather than producing a single fuel product, lignocellulosic biorefineries have the potential to serve as hubs for the production of fuels, production of petrochemical replacements, and treatment of high-moisture organic waste. A detailed techno-economic analysis and life-cycle greenhouse gas assessment are developed to explore the cost and emission impacts of integrated corn stover-to-ethanol biorefineries that incorporate both codigestion of organic wastes and different strategies for utilizing biogas, including onsite energy generation, upgrading to bio-compressed natural gas (bioCNG), conversion to poly(3-hydroxybutyrate) (PHB) bioplastic, and conversion to single-cell protein (SCP). We find that codigesting manure or a combination of manure and food waste alongside process wastewater can reduce the biorefinery's total costs per metric ton of CO2 equivalent mitigated by half or more. Upgrading biogas to bioCNG is the most cost-effective climate mitigation strategy, while upgrading biogas to PHB or SCP is competitive with combusting biogas onsite.

Recent global events emphasize the importance of a reliable energy supply. One way to increase energy supply security is through decentralized off-grid renewable energy systems, for which a growing number of case studies are researched. This review gives a global overview of the levelized cost of electricity (LCOE) for these autonomous energy systems, which range from 0.03 $2021/kWh to over 1.00 $2021/kWh worldwide. The average LCOEs for 100% renewable energy systems have decreased by 9% annually between 2016 and 2021 from 0.54 $2021/kWh to 0.29 $2021/kWh, most likely due to cost reductions in renewable energy and storage technologies. This review identifies and discusses seven key reasons why LCOEs are frequently overestimated or underestimated in research, and how this can be prevented in the future. This overview can be employed to verify findings on off-grid systems, to assess where these systems might be deployed and how costs evolve., Renewable and Sustainable Energy Reviews, 183, ISSN:18790690, ISSN:1364-0321

This paper quantifies the impact of different policy options on the economic viability of sustainable aviation fuel (SAF) production technologies. The pathways considered include isobutanol to jet from corn grain, hydroprocessed esters and fatty acids (HEFA) from inedible fats and oils, HEFA from palm fatty acid distillate, synthesized iso-paraffins from sugarcane, Fischer-Tropsch (FT) gasification and synthesis from municipal solid waste, and micro FT from wood residues. The policies considered include feedstock subsidies, capital grants, output based incentives, and two policies intended to reduce project risk. Stochastic techno-economic analysis models are used to quantify the policies’ impact on project net present value and minimum selling price of the middle distillate fuel products. None of the technology pathways studied are found to be financially viable without policy aid. The median total policy costs required for economic viability range from 35 to 337 million USD per production facility, or 0.07–0.71 USD/liter. Our results indicate that the cumulative impact of multiple policies, similar in magnitude to analogous real-world fuel policies, could result in economically viable SAF production.

Microalgae are promising host organisms for the production of encapsulated recombinant proteins such as vaccines. However, bottlenecks in bioprocess development, such as the drying stage, need to be addressed to ensure feasibility at scale. In this study, we investigated the potential of spray drying to produce a recombinant vaccine in microalgae. A transformant line of Chlamydomonas reinhardtii carrying a subunit vaccine against salmonid alphavirus was created via chloroplast engineering. The integrity of the recombinant protein after spray drying and its stability after 27 months storage at –80 °C, +4 °C and room temperature were assessed by immunoblotting. The protein withstood spray drying without significant losses. Long-term storage at +4 °C and room temperature resulted in 50% and 92% degradation, respectively. Optimizing spray drying and storage conditions should minimize degradation and favour short-term storage at positive temperatures. Using data on yield and productivity, the economics of spray drying- and freeze drying-based bioprocesses were compared. The drying stage corresponded to 41% of the total production cost. Process optimization, genetic engineering and new market strategies were identified as potential targets for cost reduction. Overall, this study successfully demonstrates the suitability of spray drying as a process option for recombinant protein production in microalgae at the industrial scale.

Integration of a grid with an under-developed remote hilly area faces various technical and geographical challenges. Thus, generation of power from renewable resources in off-grid conditions has become one of the most cost-effective and reliable solutions for such areas. The present research deals with the possible application of an integrated solar/hydro/biomass/battery-based system to generate power in autonomous mode for a remote hilly town of a northeastern Indian state. Four different cases of the integrated energy system (IES) were designed using the hybrid optimization model for electric renewable (HOMER Pro), examining the performance of each case. The best combination of the integrated system was chosen out of several cases depending upon the optimized solution that can meet the load demand of the proposed hilly town sustainably, reliably and continuously. The simulation results show that the integrated battery/biomass/hydro/solar-based system is the best optimized, cheapest and most suitable solution to generate renewable-based power for the specified location, having the lowest net present cost (NPC) of USD 644,183.70 with a levelized cost of energy (COE) of 0.1282 USD/kWh. Further, the result also indicates that the optimized configuration reduces the emission of CO2 gas in the environment compared to the battery/biomass/hydro system having the worst emission rate. A sensitivity study was also carried out with variation in load, hydro stream flow and solar irradiation, respectively that may largely affect the technical as well as economical aspect of an integrated energy system.

Industrial heat production is responsible for around 20% of total greenhouse gas emissions in Europe. To achieve the climate change goals defined in the Paris Climate Agreement, the EU commission has shifted its focus on sustainable means to generate heating. Moreover, global dependencies are leading to a re-organization of natural gas supplies. Therefore, there is a need for less vulnerable and less price-volatile solutions for heating. This paper focuses on two decarbonization technologies for industrial process heat supply: a) electricity-driven steam-generating high-temperature heat pumps (HTHP), a technology that is more efficient than fossil fuel boilers in generating steam, and b) solar parabolic trough collector (PTC), which can produce heat economically and at a minimal carbon footprint compared to other technologies. The main aim of this paper is to evaluate the levelized cost of heat (LCOH) of these technologies to fulfill a comparative techno-economic analysis. A maximum PTC collector's solar fraction limit (SFlimit) is defined to indicate when the LCOH for these two technologies is equal. This allows for distinguishing between the economic stronghold of each technology. The evaluation is carried out through the annual energy simulations using TRNSYS and Excel spreadsheets for HTHPs, while TRNSED and OCTAVE are used for the solar thermal part. Boundary conditions for European geographical constraints have been applied to establish use cases for the analysis. The result shows that the design of a PTC system with optimal SF can reach cost parity with HTHP for most of the analyzed locations. The developed methodology serves as a valuable guide to quickly determine a preferred lower carbon heat solution, thus easing the decision-making for industries.

A thorough techno-economic analysis where inherent carbon capture is examined against state-of-the-art blue hydrogen production configurations for large (100,000 Nm3/h) and very large (333,000 Nm3/h) capacities. Advanced solvent-based technologies based on post-combustion capture and auto-thermal reformer combined with a gas heated reformer are simulated with process flowsheet software and compared with the emerging chemical looping process. A network of dynamically operated packed bed reactors has been designed and modelled using an in-house code and key parameters generating uncertainties in the results have been examined in a sensitivity analysis. The chemical looping reforming process presents a higher net reforming efficiency than the benchmark cases (8.2 % higher at large scale and 1.5 % higher at very large scale) ranged 75.4–75.7 % while the specific energy for CO2 avoidance is negative in the range of −0.78 to −0.85 MJ/kgCO2. In the carbon capture cases, the chemical looping reforming in packed beds technology generated a levelised cost of hydrogen of 168.9 £/kNm3H2 for the large scale and 159.1 £/kNm3H2 for the very large scale, with the values for the benchmark cases being higher at 196.4 and 166.6 £/kNm3H2, respectively while the levelised cost of hydrogen values are 1 % higher in the benchmark cases where carbon emission price is accounted for. The carbon capture ratio is 99.9 % for the chemical looping reforming cases compared to 90–91 % for the benchmark ones, thus providing a significant foreground for the scale-up and implementation of chemical looping reforming technologies for hydrogen production.

Biorefinery feasibility is highly influenced by the early design of the best feedstock transformation pathway to obtain value-added products. Pretreatment has been identified as the critical stage in biorefinery design since proper pretreatment influences subsequent reaction, separation, and purification processes. However, many pretreatment analyses have focused on preserving and valorizing six-carbon sugars for future use in bioconversion processes, leaving aside fractions such as hemicellulose and lignin. To date, there has been no pretreatment systematization for the removal of lignocellulosic fractions. This work defines pretreatment efficacy through operational, economic, environmental, and social indicators. Thus, using the data reported in the literature, as well as the results of the simulation schemes, a multi-criteria weighting of the best-performing schemes for the isolation or removal of cellulose, hemicellulose, and lignin was carried out. As a main result, it was concluded that dilute acid is the most effective for cellulose isolation and hemicellulose removal for producing platform products based on six- and five-carbon sugars, respectively. Additionally, the kraft process is the best methodology for lignin removal and its future use in biorefineries. The results of this work help to elucidate a methodological systematization of the pretreatment efficacy in the design of biorefineries as an early feasibility stage considering sustainability aspects.