Search

Hydrogen is being increasingly considered as a chemical feedstock and energy storage vector within the iron and steel industry. This study compares the cost and CO 2 emissions associated with green steel production as a function of location for the components in its supply chain between Australia (Pilbara) and China (Beijing). Results are benchmarked against a new facility using conventional coal-based technology, producing Hot Rolled Coil (HRC) steel in China as a common final product. Green steel production in Australia using hydrogen is considerably cheaper and presents lower emissions than exporting the hydrogen and iron ore to China for subsequent processing. Costs are comparable when intermediate Hot Briquetted Iron (HBI) is exported but with increased emissions. However, utilising blue hydrogen produced in China is the most immediately dispatchable with a 35% reduction in CO 2 emissions and an increase in levelised cost of steel (LCOS) of only 11% relative to current practice. [Display omitted] • Steel production using Chinese blue H 2 (Blue Steel) is currently cost competitive. • Exporting green steel is cheaper than exporting hydrogen for steel manufacture. • Exporting Hot Briquetted Iron (HBI) does not provide a cost reduction. [ABSTRACT FROM AUTHOR]

Nuclear power is typically deployed as a baseload generator. Increased penetration of variable renewables motivates combining nuclear and renewable technologies into Integrated Energy Systems (IES) to improve dispatchability, component synergies and, through cogeneration, address multiple markets. However, combining multiple energy resources heavily depends on the proper selection of each system’s location and design limitations. In this paper, co-siting options for IES that couple nuclear and concentrating solar power (CSP) with thermal desalination are investigated. A comprehensive siting analysis is performed that utilizes global information survey data to determine possible co-siting options for nuclear and solar thermal generation in the United States. Viable co-siting options are distributed across the Southwestern U.S., with the greatest concentration of siting options in the southern Great Plains, although siting with higher solar direct normal irradiance is possible in other states such as Arizona and New Mexico. Brackish water desalination is also attractive across the southwest U.S. due to high water stress, but for brackish water desalination reverse osmosis (an electricity driven process) is most cost- and energy-efficient, which does not require co-siting with the thermal generator. The most attractive state for nuclear and thermal desalination (which is more attractive when using seawater) is Texas, although other areas may become attractive as water stress increases over the coming decades. Co-siting of all CSP and thermal desalination is challenging as attractive CSP sites are not coastal.

Nuclear power is typically deployed as a baseload generator. Increased penetration of variable renewables motivates combining nuclear and renewable technologies into Integrated Energy Systems (IES) to improve dispatchability, component synergies and, through cogeneration, address multiple markets. However, combining multiple energy resources heavily depends on the proper selection of each system's location and design limitations. In this paper, co-siting options for IES that couple nuclear and concentrating solar power (CSP) with thermal desalination are investigated. A comprehensive siting analysis is performed that utilizes global information survey data to determine possible co-siting options for nuclear and solar thermal generation in the United States. Viable co-siting options are distributed across the Southwestern U.S., with the greatest concentration of siting options in the southern Great Plains, although siting with higher solar direct normal irradiance is possible in other states such as Arizona and New Mexico. Brackish water desalination is also attractive across the southwest U.S. due to high water stress, but for brackish water desalination reverse osmosis (an electricity driven process) is most cost- and energy-efficient, which does not require co-siting with the thermal generator. The most attractive state for nuclear and thermal desalination (which is more attractive when using seawater) is Texas, although other areas may become attractive as water stress increases over the coming decades. Co-siting of all CSP and thermal desalination is challenging as attractive CSP sites are not coastal. [ABSTRACT FROM AUTHOR]

The growing interest in bamboo fibers for pulp, paper, and board production in the USA necessitates a comprehensive financial viability assessment. This study conducts a detailed technoeconomic analysis (TEA) of bamboo fiber production, primarily for the consumer hygiene tissue market although it is also applicable to other industrial uses. The economic viability of two pulping methods – alkaline peroxide mechanical pulping (APMP) and ammonium bisulfite chemical pulping (ABS) – was explored within three different pulp mill settings to supply pulp to two nonintegrated tissue and towel mills in South Carolina, USA. The target was to produce wet lap bamboo bleached pulp at 50% consistency and 70% ISO brightness. Despite higher initial capital invesment and operating costs, ABS achieved a lower minimum required selling price – USD 544 to 686 per bone dry metric ton (BDt = 1000 BDkg) – in comparison with USD 766 to 899 BDt−1 for APMP. This price advantage is partly due to an additional revenue stream (lignosulfonate byproduct), which not only boosts revenue but also circumvents the need for expensive chemical recovery systems. When compared with traditional kraft pulping, both methods require significantly lower capital investments, with minimum required selling prices (estimated to achieve 16% IRR) below current market rates for extensively used bleached kraft pulps in the USA tissue industry. The economic benefits derive from several factors: the low cost of bamboo as raw material, reduced capital needs for new pulping technologies, lower transportation costs from the pulp mill to tissue and towel manufacturing facilities, and the high market price of bleached kraft pulp. [ABSTRACT FROM AUTHOR]

Increasing development of wind and solar generation in the power sector can create economic opportunities for the deployment of water electrolyzers that produce hydrogen. Temporal variation in the marginal cost of energy in future decarbonized grids can make it favorable for electrolyzers to dispatchably ramp hydrogen production up and down in response to low‐ and high‐cost times. Using this strategy, low‐cost hydrogen production is enabled by electrolyzers that are low‐capital cost and tolerant to frequent on/off cycling. Ramping down hydrogen production to a designated turndown ratio can avoid performance degradation caused by on/off cycling by not shutting the electrolyzer completely off. This comes with a slight cost penalty which can be minimized if the turndown ratio is low (i.e., the system ramps down hydrogen production to close to zero). These results suggest that electrolyzers integrated into future power systems are likely to benefit from the ability to ramp operation up and down quickly and operate in a standby mode. This analysis forms a basis for comparative tradeoffs between electrolyzer capital cost, operating strategy, and system durability and demonstrates the importance of considering all three factors in technoeconomic analysis. [ABSTRACT FROM AUTHOR]

Sustainability faces many challenges, including the availability of materials necessary for technological advancement. Rare earth elements (REEs), for example, are key materials for several manufacturing industries that can unlock renewable energy and sustainable development. In this study, a decanter centrifuge has been employed to successfully separated phosphoric acid and REE-containing particles from phosphoric acid sludge with concentrations ranging from 1000 to 2200 ppm REEs. Operating efficiently with up to 35 wt.% solids, the centrifuge was demonstrated to achieve approximately 95% phosphoric acid recovery and 90% REE recovery in a single pass, eliminating the need for additional processing steps. This breakthrough supports a proposed rare earth oxide (REO) recovery process integrating phosphoric acid (PA), elemental phosphorus (P4), and REO into two potential pathways: PA-REO and PA-P4-REO. These processes aim to reintroduce recovered phosphoric acid into the main product to significantly increase output and revenue. Post-separation, phosphorus-rich particles can be converted to P4, while REE-containing solids undergo further treatment including acid leaching, extraction/stripping, precipitation, and calcination to produce a marketable REO material. Technoeconomic analysis indicates promising profitability, with the PA-REO process showing a delta net present value (∆NPV) of USD 441.8 million over a 12-year period and expected return within a year of construction, while the PA-P4-REO process yields a ∆NPV of USD 178.7 million over a 12-year return period. Both pathways offer robust financial prospects and demonstrate the feasibility of commercial-scale REO recovery from phosphoric acid sludge, offering an economically feasible approach to produce REEs for future sustainable development challenges related to sustainability. [ABSTRACT FROM AUTHOR]

Summary: Building sustainable platforms to produce biofuels and specialty chemicals has become an increasingly important strategy to supplement and replace fossil fuels and petrochemical‐derived products. Terpenoids are the most diverse class of natural products that have many commercial roles as specialty chemicals. Poplar is a fast growing, biomassdense bioenergy crop with many species known to produce large amounts of the hemiterpene isoprene, suggesting an inherent capacity to produce significant quantities of other terpenes. Here we aimed to engineer poplar with optimized pathways to produce squalene, a triterpene commonly used in cosmetic oils, a potential biofuel candidate, and the precursor to the further diversified classes of triterpenoids and sterols. The squalene production pathways were either re‐targeted from the cytosol to plastids or co‐produced with lipid droplets in the cytosol. Squalene and lipid droplet co‐production appeared to be toxic, which we hypothesize to be due to disruption of adventitious root formation, suggesting a need for tissue specific production. Plastidial squalene production enabled up to 0.63 mg/g fresh weight in leaf tissue, which also resulted in reductions in isoprene emission and photosynthesis. These results were also studied through a technoeconomic analysis, providing further insight into developing poplar as a production host. [ABSTRACT FROM AUTHOR]

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

A multitubular Fischer–Tropsch (FT) reactor with gas recycle and a cobalt‐based catalyst is simulated by a 2D fixed‐bed model that considers the complex kinetics, all relevant mass and heat transfer aspects, and also the influence of the changing molar flow rate by the FT reaction, of pressure drop, and of formation of steam, which decreases the reaction rate of FT synthesis. Optimal values of gas velocity and single‐tube diameter and length are determined by a technoeconomic analysis. The comparison of the data of the FT reactor modeled in this work with data of commercial reactors indicates that the used model reflects reality well and is reliable. A superficial gas velocity of 0.5 m s−1, a tube diameter of 3 cm, and a length in a range of 12–20 m are appropriate for a high production rate of C2+‐hydrocarbons with minimal operating costs of the FT unit, even for a large range of the electricity price from 0.06 to 0.3 € kWh−1. [ABSTRACT FROM AUTHOR]

Alpha-1 antitrypsin deficiency (AATD) is a genetic disorder characterized by the insufficient production of the AAT protein. Due to availability limitations, not all AATD patients receive protein therapy treatment. In this study, the technoeconomic analysis of different processes (conventional and intensified) producing 200 kg/year of PEGylated recombinant AAT (PEG-AAT) using a Chinese hamster ovary cell line was investigated. All bioprocesses consist of upstream, downstream, and PEGylation sections. A base-case model (process A) of the conventional fed-batch production bioreactor was developed using SuperPro Designer software (Version 13) to evaluate the economic feasibility of the process. The cost of goods (COG) was estimated to be approximately USD 387.6/g. Furthermore, an intensified process (B) was modeled and evaluated to reduce the COG. Process intensification was implemented in the process (N-1 perfusion bioreactor). The specific operating COG for process B was found to be 10% less than that of process A. Scenario analysis was performed to assess the impact of process capacity (100–1000 kg/year) and cell-specific productivity (30–90 pg/cell/day). With an increase in process capacity, the specific operating COG was reduced for all processes. Increasing cell-specific productivity decreases the specific operating COG at different rates for each process, depending on the titer level. Future investigations into the PEGylation section are required since it has the highest COG of all the sections. [ABSTRACT FROM AUTHOR]

Renewable Hydrogen is a key building block for a sustainable energy economy. An attractive resource for its production is waste biomass. This contribution analyses a promising new Biomass-to-H 2 two-step approach, consisting of (1) biomass oxidation to formic acid and methyl formate in the so-called OxFA-Process and (2) hydrogen generation by dehydrogenation or decarbonylation of these intermediates. This contribution explains a novel hydrogen production concept and compares three distinct process routes for their efficient implementation. By using Aspen Plus® V12 the process was designed and optimized to achieve maximum hydrogen yield. An economic analysis allowed to compare the different characteristics of each process concept and to select the most promising option. The chosen concept was subject to a detailed cost and sensitivity analysis showing that this new route has high potential and competitiveness for hydrogen production from waste biomass. [Display omitted] • Novel catalytic concept for renewable H 2 production from waste biomass via intermediate formic acid and methyl formate. • The mild operating conditions of the novel concept are favourable for decentralized hydrogen production. • Process simulation allowed the selection of the most economic process route for hydrogen production. • Economic feasibility of the novel route for hydrogen production for biomass wastes is demonstrated. [ABSTRACT FROM AUTHOR]

In the recent times, the application of process simulation software has found its way to the simulation of bioprocesses. Presently, bioprocesses are simulated and technoeconomic analysis is performed in commercially available software for such as SuperPro Designer®, Aspen Plus® etc. These softwares are not freely available and therefore, there exists a need for an open source software for the simulation of bioprocesses. Furthermore, the chemical process softwares show compatibility issues, when used for bioprocesses. More recently, an open source process simulator called DWSIM was introduced for the simulation of chemical processes. However, the applicability and compatibility of DWSIM for complex bioprocess simulation involving microbial biomass has not been reported yet. Therefore, the present study evaluates and reports the simulation results of the bioethanol production process developed by NREL (National Renewable Energy Laboratory, USA), performed in DWSIM. The simulator results were compared to those of existing commercial software, and the results showed good agreement with the literature. This suggests that DWSIM could be a promising alternative for bioprocess flowsheeting and simulation, and further technoeconomic analysis. [ABSTRACT FROM AUTHOR]

With the increase in population at an immense rate, electricity demand is growing exponentially. Researchers and policymakers are seeking alternating means of power generation to meet the load demand. These resources should be cost-effective, environmentally friendly and least carbon emissions. To mitigate the load demand Renewable Energy Sources (RES) are integrated into electrical networks. In this work, an off-grid solar photovoltaic (PV) system is designed for rural areas of Dera Ghazi Khan (DG Khan), Pakistan. These areas often lack access to reliable grid power. Installing PV systems in these areas can help provide a reliable source of electricity, reduce reliance on fossil fuels, and improve living conditions. This case study is simulated using PVsyst 7.2. of Roonghan village such as hospitals, shops, and residential houses for techno-economic analysis of off-grid solar PV. The economic viability shows that installing off-grid solar PV in DG Khan is much cheaper. The electricity taken from the grid that's almost 80.01%is expensive. This case study helps other researchers and policymakers to mitigate the electricity requirement of remote areas located far away from the national grid. To install a transmission line, having cost $26.98 corer but using an off-grid to provide electricity to the same area is $2.16 corer. Additionally, it integrates Battery Energy Storage (BES) with Renewable Energy Sources (RES) to achieve a 5 % annual energy cost reduction and enhanced self-sufficiency, filling a gap in existing literature.

Concentrating solar thermal (CST) power towers can provide high flux concentrations at commercial scale. As a result, CST towers exhibit potential for high-temperature solar industrial process heat (SIPH) applications. However, at higher operating temperatures, thermal radiation losses can be significant. This study explores the trade-off between thermal and optical losses for SIPH applications using a collection of three case studies at operating temperatures that range from 900-1,550 °C. We assume blackbody radiation to represent the thermal losses at the receiver and we use ray tracing to estimate the optical losses. The results show the impact of process temperature on the maximum attainable system efficiency, as well as the higher flux concentration requirements as the temperature increases.

Plants and microbes share common metabolic pathways for producing a range of bioproducts that are potentially foundational to the future bioeconomy. However, in planta accumulation and microbial production of bioproducts have never been systematically compared on an economic basis to identify optimal routes of production. A detailed technoeconomic analysis of four exemplar compounds (4-hydroxybenzoic acid [4-HBA], catechol, muconic acid, and 2-pyrone-4,6-dicarboxylic acid [PDC]) is conducted with the highest reported yields and accumulation rates to identify economically advantaged platforms and breakeven targets for plants and microbes. The results indicate that in planta mass accumulation ranging from 0.1 to 0.3 dry weight % (dwt%) can achieve costs comparable to microbial routes operating at 40 to 55% of maximum theoretical yields. These yields and accumulation rates are sufficient to be cost competitive if the products are sold at market prices consistent with specialty chemicals ($20 to $50/kg). Prices consistent with commodity chemicals will require an order-of-magnitude-greater accumulation rate for plants and/or yields nearing theoretical maxima for microbial production platforms. This comparative analysis revealed that the demonstrated accumulation rates of 4-HBA (3.2 dwt%) and PDC (3.0 dwt%) in engineered plants vastly outperform microbial routes, even if microbial platforms were to reach theoretical maximum yields. Their recovery and sale as part of a lignocellulosic biorefinery could enable biofuel prices to be competitive with petroleum. Muconic acid and catechol, in contrast, are currently more attractive when produced microbially using a sugar feedstock. Ultimately, both platforms can play an important role in replacing fossil-derived products.

The rational management of water, which is determined by the Framework Directive 2000/60/EC of the EU, is a contractual obligation of the Agricultural Sector of Cyprus, both towards the European Union and the next generations of Cypriot citizens. To make decisions about sustainable water use and improve water use, it is necessary to understand the water use of crops in different water-use areas. Especially in large water projects in Cyprus, there must be a good way to determine the water use of crops so that the correct use of crops can be ensured, thus eliminating problems such as a lack of new information about the crop area and agricultural evaporation, Demand, and water. In most projects, water is managed and supplied based on historical data, and current information is available to determine water demand and availability for large areas. This paper also adds, apart from the clear positive effect of remote sensing and new technologies in crop irrigation, to the emerging need for advisory services for the diffusion of innovation to Cypriot farmers since the estimation of crop water requirements is part of estimating the carbon footprint under the project CARBONICA (EU Funded) for carbon farming. [ABSTRACT FROM AUTHOR]

This study presents a technical and economic assessment of the potential of a second-generation biorefinery process targeted at the conversion of lignocellulosic biomass to ethylene and propylene. The process was developed through the integration of several catalytic processes involving hydrolysis, hydrogenation, decarboxylation, metathesis and cracking. Additional alternative configurations were developed as an improvement to the base case process using the combustion of all generated hydrocarbon and solid by-products, and reduced levulinic acid concentration in the hydrolysis process. The viability of the proposed bio-olefin production route was assessed using the target product yield, energy efficiencies and the minimum olefin selling price (MOSP). The results revealed that 30 ktonnes per year of lower olefins can be produced from the process at a plant processing capacity of 701 ktonnes of sugarcane bagasse per year with a base case energy efficiency and MOSP of 40% and $4.8/kg respectively. However, a reduction in the energy requirement of the hydrolysis unit in the alternative configurations (scenarios A , B and C ) resulted in scenario C as the most viable process with a reduced MOSP of $2.8/kg. A sensitivity analysis of the effect of the major cost drivers on the MOSP showed that the cumulative effect of the reduction in the feedstock cost, nitrogen gas cost and other economic parameters could lead to a more cost-competitive MOSP. Therefore, the developed process is a viable option for the production of ethylene and propylene from lignocellulosic biomass. [ABSTRACT FROM AUTHOR]

Co-generation of hydrogen with value-added by-products is a promising route for affordable low-carbon hydrogen. This work presents a system for and a technoeconomic analysis of hydrogen with the co-generation of chlorine and sodium hydroxide from waste brine. The system uses a conceptual triple-junction gallium arsenide (3-J GaAs)-based photoelectrochemical (PEC) reactor at high solar concentrations (50–500x). The base case of 200x solar concentration results in a solar-to-chemical (SCE) efficiency of 15% and a levelized cost of hydrogen (LCOH) production of $15.76/kgH2. Revenue from by-products ($45.36/kgH2) is critical for offsetting the operating costs, with sodium hydroxide constituting 64% of total by-product revenue. The sensitivity analysis showed that under favorable combinations of the key variables (sodium hydroxide price, waste brine pretreatment price, and PEC replacement lifetime) PEC hydrogen generation from waste brine would be viable and have prices reaching $0.78/kgH2. • Analysis of concentrated triple-junction photoelectrochemical hydrogen production. • Desalination waste brine as feed with co-production of chlorine and sodium hydroxide. • Results show that solar hydrogen can be reduced below the U.S. Department of Energy target of $1/kg H2. • Reactor lifetime, concentration factor, and co-product prices have economic leverage. [ABSTRACT FROM AUTHOR]

Manufacturing low-carbon ammonia (NH 3) is paramount for the green transition of the chemical industry and society at large. The conventional Haber-Bosch (HB) process based on steam methane reforming (SMR) entails whopping CO 2 emissions (i.e., 400 Mt y−1), therefore we propose a sustainable plant design comprising water electrolysis and cryogenic distillation for H 2 and N 2 production, respectively. This electrified configuration powered by wind energy affords 80% lower carbon emissions than the conventional SMR-based process. However, the electrolyser unit can represent between 36 and 61% of the total capital cost, depending on its energy efficiency, and its high energy demand drives the electricity cost which accounts for more than 68% of the plant operational costs. Thus, even with anticipated improvements in efficiency of the electrolyser unit, the Levelized Cost of Production (LCOP) of e-NH 3 in a 2050 scenario is 65% higher than the current benchmark; nonetheless, the two processes could be equally viable with a 135.8 $ t CO2 −1 carbon penalty on the average conventional process. Notably, the cost of electricity is the most prominent cost driver in the e-process, which could be more economically viable than the fossil counterpart with electricity prices below 12.5 $ MWh−1. These findings provide evidence that the proposed e-process can replace the commercial benchmark in small-scale, standalone applications. [Display omitted] • H 2 from water electrolysis enables green NH 3 production with 98% CO 2 reduction. • Water electrolyzer accounts for 36% of CAPEX and 68% of OPEX comes from electricity. • Electricity price below 12.5 $ MWh−1 makes e-NH 3 economically viable. • Production cost of e-NH 3 is equal to benchmark with 117.6 $ ton co2 carbon tax. [ABSTRACT FROM AUTHOR]

In recent years, aqueous organic redox flow batteries (AORFBs) have attracted considerable attention due to advancements in grid‐level energy storage capacity research. These batteries offer remarkable benefits, including outstanding capacity retention, excellent cell performance, high energy density, and cost‐effectiveness. The organic electrolytes in AORFBs exhibit adjustable redox potentials and tunable solubilities in water. Previously, various types of organic electrolytes, such as quinones, organometallic complexes, viologens, redox‐active polymers, and organic salts, were extensively investigated for their electrochemical performance and stability. This study presents an overview of recently published novel organic electrolytes for AORFBs in acidic, alkaline, and neutral environments. Furthermore, it delves into the current status, challenges, and prospects of AORFBs, highlighting different strategies to overcome these challenges, with special emphasis placed on their design, composition, functionalities, and cost. A brief techno‐economic analysis of various aqueous RFBs is also outlined, considering their potential scalability and integration with renewable energy systems. [ABSTRACT FROM AUTHOR]

The relatively high concentration of thorium and uranium in monazite poses significant environmental issues in the extraction process of rare earth elements from monazite if left untreated. A new process route that recovers both thorium and uranium as oxides has been proposed, and an analysis of its economic feasibility is presented in the current paper, based on analysis and processing of a Korean monazite sample. Comparative evaluations with existing acidic and alkaline routes have also been carried out. It was estimated that the largest proportion of the operational cost for the new process related to the materials and reagent costs. Sensitivity analysis predicted that the value of neodymium oxide followed by Heavy Rare Earth Oxides (HREO) and praseodymium oxide affect the revenue significantly. Increasing the average basket price of the total rare earths oxide by 1.5 times would result in revenues of US$158.8 million/year for the proposed route, compared to US$161.5 and US$156.3 million/year for the alkaline and acidic routes, respectively. The discounted cash flow analysis and the resulted Net Present Value (NPV) suggested that the proposed processing route was in fact the only process estimated to be economically feasible with the payback period expected to be around 4.5 years. The sale of thorium oxide and uranium oxide by-products of the proposed route contributed to the positive discounted NPV. It was also estimated that a minimum sale price of US$20/kg total rare earth oxide is required to ensure all the processes generate a positive discounted NPV. These results shown that the proposed new processing route is estimated to be economically feasible.

There is an urgent need for building energy services that are not only low-carbon but reliable. District energy systems (DES) have the potential to meet building power, heating and cooling needs efficiently and reliably, but further research is needed to understand their coupling with local renewable energy sources such as biomass. Here we assess the cost and greenhouse gas implications of using bioenergy from local organic waste to power DES in California communities. We describe a set of possible scenarios for bioenergy integration into DES, including fuel switching and retrofitting of existing systems and DES expansion through new projects. In all locations, DES have higher combined capital and operating expenses (ranging from $5–12 million) than conventional fossil fuel building thermal systems. However, the net amortized annual cost of DES can reach as low as 70% that of the conventional system from the sale of excess electricity. Bioenergy-powered DES can offer a cost of carbon abatement on par with distributed solar-powered building thermal systems (50% less to 34% more). Furthermore, upgrading existing DES from fossil to renewable natural gas represents an immediate economical path to decarbonize buildings.

A central question surrounding possible human exploration of Mars is whether crewed missions can be supported by available technologies using in situ resources. Here, we show that photovoltaics-based power systems would be adequate and practical to sustain a crewed outpost for an extended period over a large fraction of the planet’s surface. Climate data were integrated into a radiative transfer model to predict spectrally-resolved solar flux across the Martian surface. This informed detailed balance calculations for solar cell devices that identified optimal bandgap combinations for maximizing production capacity over a Martian year. We then quantified power systems, manufacturing, and agricultural demands for a six-person mission, which revealed that photovoltaics-based power generation would require (Formula presented.) 10 t of carry-along mass, outperforming alternatives over ∼50% of Mars’ surface.

Electric Vehicle (EV) usage across the world has rapidly increased in the recent times and has opened the doors for researchers working in the area of EV charging station (EVCS). The presence of EVs in India is equally growing and creating a charging infrastructure resource is a big challenge. In this paper, biogas–solar powered EVCS is proposed for a typical location in South Indian state of Karnataka. Techno economic assessment and environmental analysis of PV-Grid with Biogas Powered EVCS in a microgrid was comprehensively carried out using Hybrid Optimization of Multiple Energy Resources (HOMER) software. Results obtained demonstrated that the dependency on the grid purchase was significantly reduced with improved environment benefits in terms of lesser CO2 emissions. This study shall be beneficial in renewables based EVCS infrastructure development.

The efficiency by which monomers may be recovered during the chemical recycling of plastic waste has thus far dominated the discussion over which future polymer chemistries might be more sustainable than those in use today. However, at scale, other factors emerge as equally important, such as the costs of primary versus secondary resin production as well as the energy and carbon intensity of circular manufacturing processes. We apply systems analysis to identify problematic chemical processes used for the primary production of plastics designed for infinite recyclability: polydiketoenamine (PDK) resins from novel triketone and amine monomers. Leveraging this knowledge, we advance a less intensive process for triketone production, which lowers the cost of primary PDK production by 57% and results in 66% less life-cycle greenhouse gas (GHG) emissions. Using the automotive sector as a case study, we discuss the impact of replacing nonrecyclable polyurethane with circular PDK over the next 60 years. We find that the cumulative GHG emissions associated with introducing PDK are half those of staying the course with polyurethane. However, the extent to which circularity is realized through targeted collection and sorting plays the dominant role in determining how much of those savings is practically achievable.

Technoeconomic analysis (TEA) is commonly used to determine economic viability of power-generating technologies, including concentrating solar power (CSP) and thermal (CST) production plants. Levelized cost of electricity (LCOE) and analogous measures provide an estimate of long-term costs for operating power plants over their designed lifetimes by accounting for revenues and costs in a time-discounted manner. While these measures are effective when assessing a technology’s total lifecycle costs and productivity under various designs, TEA of candidate incremental technology improvements from the lens of LCOE can be limited when required investment and LCOE impacts are small. In this work, we propose a novel metric for TEA of a plant component technology that recasts relative changes in levelized system costs into component-specific capital cost budgets. This measure, which we refer to as the equivalent breakeven installed cost, is the maximum budget for the technology component that leads to improved levelized costs. We illustrate the usefulness of this metric using the example of candidate heliostat improvements for a CSP tower plant. Here, the results suggest that a reduction in mirror washing costs yield a total plant O&M cost of $37/kWe-yr, which is a breakeven proposition if the average reflectance is reduced from 0.90 to 0.85 as a result of the cost savings.

In response to technological advances, environmental concerns, and the depletion of conventional energy sources, the world is increasingly focusing on renewable energy sources (RES) as a means of generating electricity in a more sustainable and environmentally friendly manner. Türkiye, with its advantageous geographical location, long hours of sunshine, and favourable climatic conditions, has a high potential for the use of solar energy. The objective of this study was to identify an energy system that minimizes investment costs while optimizing the levelized cost of energy (LCOE) and minimizing greenhouse-gas (GHG) and carbon dioxide emissions. To achieve this, the study used the concept of nanogrids (NGs) and carried out different evaluations for electric vehicle charging stations (EVCS) at different energy levels connected to the grid. The research focused on classic apartment buildings and multistory condominium-style buildings in Istanbul, Türkiye. Using HOMER Grid 1.11.1 version software, the study identified two optimal configurations: a PV–GRID system with 7 kW photovoltaic capacity and a PV–WT–GRID system with 90 kW PV capacity and 6 kW wind-turbine capacity. These configurations had a significantly lower LCOE compared to the cost of electricity from the conventional grid. When examining the sensitivity to economic factors, it was observed that the net present cost (NPC) and LCOE values fluctuated with electricity prices, inflation rates, and equipment costs. In particular, the two optimal configurations did not include a battery energy-storage system (BESS) due to the low energy demand in the PV–GRID system and the efficiency of the wind turbines in the PV–WT–GRID system. This highlights the need to tailor energy solutions to specific consumption patterns and resource types. In conclusion, the adoption of PV–GRID and PV–WT–GRID systems in Istanbul's urban buildings demonstrates economic viability and environmental benefits, highlighting the importance of renewable energy sources, particularly solar PV, in mitigating energy-related environmental challenges, such as reducing CO2 emissions and reducing dependence on conventional grid electricity. [ABSTRACT FROM AUTHOR]

The study aimed to evaluate the effect of utilizing solar energy as a heat source for gasification reactions during the production of methanol from corn stover. For this purpose, two biorefinery scenarios were modelled: a standalone scenario where gasification was performed in a conventional dual-bed gasifier, and a solar-aided scenario where solar energy was used to drive the gasification reactions. In the solar-aided scenario, biochar was exported as a co-product rather than combusted. Results obtained revealed that the incorporation of solar energy could enhance the net gasification efficiency by 10 to 24%, depending on the biomass moisture content. Also, the biorefinery energy conversion efficiency was found to be 48% for the standalone scenario and 61% for the solar-aided scenario. Moreover, the export of biochar as a co-product resulted in a 35% decrease in potential environmental impact. Furthermore, the methanol production costs could be 0.31 $/litre for the standalone scenario and 0.50 $/litre for the solar-aided scenario. While the minimum biochar selling price was estimated to be 13.04\ $/GJ (0.37 $/kg). These results suggest that the adoption of solar-aided gasification could be one way to advance the circular bioeconomy concept, where lignocellulose is used to produce not only fuels but also bio-products capable of gradually substituting fossil-based alternatives. [ABSTRACT FROM AUTHOR]

In a blue ammonia plant, hydrogen required for ammonia synthesis is traditionally produced through steam reforming. This process is cost competitive but has the drawbacks of high CO2 emissions and excessive energy consumption. On the other hand, in a green ammonia plant, hydrogen production through water electrolysis avoids CO2 emissions and utilizes renewable energy sources. However, high stack costs and electricity prices degrades the economic viability of the process. Recognizing the potential benefits of both green and blue ammonia production methods, novel hybrid processes have been proposed to integrate these approaches. A thermoneutral tri-reformer has been introduced as a replacement for the energy-intensive steam reforming process, offering a means to eliminate CO2 emissions. In the green ammonia process, hydrogen generated by a water electrolyzer, along with nitrogen obtained from an air separation unit (ASU), are employed for ammonia synthesis. However, the high-purity oxygen produced as a byproduct from the electrolyzer and ASU has not been utilized thus far. This oxygen can be fed into the tri-reformer to produce blue hydrogen or syngas. To evaluate the technical and economic advantages resulting from the integration of these systems, a techno-economic assessment was conducted on these hybrid processes as well as conventional ones in the literature [3]. The results demonstrate that the proposed processes exhibit superior economic performance compared to conventional approaches, highlighting the potential benefits of system integration. [ABSTRACT FROM AUTHOR]

Recently, the industrial focus has shifted to renewable raw materials due to the exhaustion and rising pressures about environmental and political issues. Lignocellulosic biowaste can be derived from a range of sources, such as animal manure, forestry waste, and agricultural waste, and it can be transformed into lactic acid through a biochemical process. There are 942.63 million cattle in the world and annually generate 3.7 billion tons of manure, which could be used to produce lactic acid. The economic viability of a lactic acid plant from cow manure has not yet been determined and is, thus, considered in this study. Using the modeling program Aspen Plus data and other sources, as well as collecting all economic inputs, the feasibility analysis of a lactic acid plant handling cow manure is assessed in this paper. Three scenarios are calculated to check the feasibility depending on the plant size: scenario I handles 1,579,328 t·year−1, scenario II handles 789,664 t·year−1, and scenario III handles 315,865 t·year−1. The results demonstrate that treating the tested lignocellulosic biomass for the manufacture of lactic acid is economically feasible because the economic analysis shows positive net present values for scenarios I, II, and III. The technoeconomic analysis reveals that the minimum lactic acid selling price for scenario I is 0.945 EUR·kg−1, which is comparable to the cost of commercial lactic acid produced from starch feedstock. Scenario II achieves a minimum selling price of 1.070 EUR·kg−1, and scenario III 1.289 EUR·kg−1. The sensitivity analysis carried out reveals that the factor with the biggest impact on the NPV is the yield. Moreover, this study provides a model of industrial application and technoeconomic evaluation for lactic acid production from cow manure. [ABSTRACT FROM AUTHOR]

Near-term decarbonization of aviation requires energy-dense, renewable liquid fuels. Biomass-derived 1,4-dimethylcyclooctane (DMCO), a cyclic alkane with a volumetric net heat of combustion up to 9.2% higher than Jet A, has the potential to serve as a low-carbon, high-performance jet fuel blendstock that may enable paraffinic bio-jet fuels to operate without aromatic compounds. DMCO can be produced from bio-derived isoprenol (3-methyl-3-buten-1-ol) through a multistep upgrading process. This study presents detailed process configurations for DMCO production to estimate the minimum selling price and life-cycle greenhouse gas (GHG) footprint considering three different hydrogenation catalysts and two bioconversion pathways. The platinum-based catalyst offers the lowest production cost and GHG footprint of $9.0/L-Jet-Aeq and 61.4 gCO2e/MJ, given the current state of technology. However, when the supply chain and process are optimized, hydrogenation with a Raney nickel catalyst is preferable, resulting in a $1.5/L-Jet-Aeq cost and 18.3 gCO2e/MJ GHG footprint if biomass sorghum is the feedstock. This price point requires dramatic improvements, including 28 metric-ton/ha sorghum yield and 95-98% of the theoretical maximum conversion of biomass-to-sugars, sugars-to-isoprenol, isoprenol-to-isoprene, and isoprene-to-DMCO. Because increased gravimetric energy density of jet fuels translates to reduced aircraft weight, DMCO also has the potential to improve aircraft efficiency, particularly on long-haul flights.

Forage sorghum is a promising feedstock for the production of biofuels and bioproducts because it is drought tolerant, high-yielding, and familiar to farmers across the world. However, sorghum spans a diverse range of phenotypes, and it is unclear which are most desirable as bioenergy feedstocks. This paper explores four forage sorghum types, including brown-midrib (bmr), non-bmr, photoperiod sensitive (PS), and photoperiod insensitive (non-PS), from the perspective of their impact on minimum bioethanol selling price (MESP) at an ionic liquid pretreatment-based biorefinery. Among these types, there are tradeoffs between biomass yield, lignin content, and starch and sugar contents. High biomass-yielding PS varieties have previously been considered preferable for bioenergy production, but, if most starch and sugars from the panicle are retained during storage, use of non-PS sorghum may result in lower-cost biofuels (MESP of $1.26/L-gasoline equivalent). If advances in lignin utilization increase its value such that it can be dried and sold for $0.50/kg, the MESP for each scenario is lowered and non-bmr varieties become the most attractive option (MESP of $1.08/L-gasoline equivalent). While bmr varieties have lower lignin content, their comparatively lower biomass yield results in higher transportation costs that negate its fuel-yield advantage.

With a diverse and widely distributed global resource base, woody biomass is a compelling organic feedstock for conversion to renewable liquid fuels. In California, woody biomass comprises the largest fraction of underutilized biomass available for biofuel production, but conversion to fuels is challenged both by recalcitrance to deconstruction and by toxicity toward downstream saccharification and fermentation due to organic acids and phenolic compounds generated during pretreatment. In this study, we optimize pretreatment and scale-up of an integrated one-pot process for deconstruction of California woody biomass using the ionic liquid (IL) cholinium lysinate [Ch][Lys] as a pretreatment solvent. By evaluating the impact of solid loading, solid removal, yeast acclimatization, fermentation temperature, fermentation pH, and nutrient supplementation on final ethanol yields and titers, we achieve nearly full conversion of both glucose and xylose to ethanol with commercial C5-utilizing Saccharomyces cerevisiae. We then demonstrate process scalability in 680 L pilot-scale fermentation, achieving >80% deconstruction efficiency, >90% fermentation efficiency, 27.7 g/L ethanol titer, and >80% ethanol distillation efficiency from the IL-containing hydrolysate post fermentation. This fully integrated process requires no intermediate separations and no intermediate detoxification of the hydrolysate. Using an integrated biorefinery model, current performance results in a minimum ethanol selling price of $8.8/gge. Reducing enzyme loading along with other minor process improvements can reduce the ethanol selling price to $3/gge. This study is the largest scale demonstration of IL pretreatment and biofuel conversion known to date, and the overall biomass-to-ethanol efficiencies are the highest reported to date for any IL-based biomass-to-biofuel conversion.

The use of new vehicle technologies such as fuel cell hybrid electric and fully electric powertrains for biomass feedstock supply is an unexplored solution to reducing biofuel production cost, greenhouse gas emissions, and health impacts. These technologies have found success in light-duty vehicle applications and are in development for heavy-duty trucks. This study presents the first detailed stochastic techno-economic analysis and life-cycle assessment of biomass feedstock supply systems with diesel, fuel cell hybrid electric, and fully electric trucks and determines their impacts on biofuel production considering butanol as a representative biofuel. This study finds that fuel cell hybrid electric and fully electric trucks consume less energy relative to the diesel-powered truck regardless of the evaluated circumstances, including payloads of truck (loaded and empty), pavement types (gravel and paved), road conditions (normal and damaged), and road networks (local and highways). The use of fuel cell hybrid and fully electric trucks powered by H2-fuel and renewable sources of electricity, respectively, results in a large reduction in cost and carbon footprint, specifically for a long-distance hauling, and minimize other economic and environmental impacts. While the economic advantage of fuel cell hybrid electric vehicle is dependent on the price of H2-fuel and road conditions, use reduces the GHG emissions of biobutanol per 100 km-trucking-distance by 0.98–10.9 gCO2e/MJ. Results show that converting to fully electric truck transport decreases the biobutanol production cost and GHG emissions per 100 km-trucking-distance by 0.4–7.3 cents/L and 0.78 to 9.1 gCO2e/MJ, respectively. This study establishes the foundation for future investigations that will guide the development of economically, socially, and environmentally sustainable biomass feedstock supply system for cellulosic biorefineries or other goods transportation systems.

Biomass sorghum is a promising feedstock for cellulosic biorefineries because of its high yield and drought tolerance. However, the difficulty of effectively drying sorghum in some regions means that it may require different handling than previously studied grassy feedstocks. This study compares the delivered cost and life-cycle greenhouse gas (GHG) footprint of field drying and baling, module storage (wrapped, densely packed biomass), pelletizing, and ensiling. Ensiling has not been widely considered for use in bioenergy production. For farms within 66 km of the biorefinery, ensiled biomass is of the lowest cost and GHG strategy despite additional cost and energy demand for hauling wet biomass. Field drying and baling, if feasible, is the most cost-effective option for sorghum between 66 km and 104 km, beyond which pellets are preferable. A 2000 bone-dry-metric ton (bdt)/day biorefinery can source sorghum with 18 bdt/ha yield cultivated on 5% of surrounding land at costs ranging from $122 (silage) to $167 (pellets)/bdt and a life-cycle GHG footprint of 111 (silage) to 179 kg CO2e/bdt (pellets). With 28 bdt/ha biomass yield, 10% cultivation of surrounding land, and low fertilizer application, costs can range from $66 (silage) to $85 (pellets)/ bdt and GHG footprint of 43 (silage) to 96 kg CO2e (pellets)/bdt.

Biopharmaceutical protein production using transgenic plant cell bioreactor processes offers advantages over microbial and mammalian cell culture platforms in its ability to produce complex biologics with simple chemically defined media and reduced biosafety concerns. A disadvantage of plant cells from a traditional batch bioprocessing perspective is their slow growth rate which has motivated us to develop semicontinuous and/or perfusion processes. Although the economic benefits of plant cell culture bioprocesses are often mentioned in the literature, to our knowledge no rigorous technoeconomic models or analyses have been published. Here we present technoeconomic models in SuperPro Designer® for the large-scale production of recombinant butyrylcholinesterase (BChE), a prophylactic/therapeutic bioscavenger against organophosphate nerve agent poisoning, in inducible transgenic rice cell suspension cultures. The base facility designed to produce 25 kg BChE per year utilizing two-stage semicontinuous bioreactor operation manufactures a single 400 mg dose of BChE for $263. Semicontinuous operation scenarios result in 4-11% reduction over traditional two-stage batch operation scenarios. In addition to providing a simulation tool that will be useful to the plant-made pharmaceutical community, the model also provides a computational framework that can be used for other semicontinuous or batch bioreactor-based processes.

Coproduction of high-value bioproducts at biorefineries is a key factor in making biofuels more cost-competitive. One strategy for generating coproducts is to directly engineer bioenergy crops to accumulate bioproducts in planta that can be fractionated and recovered at biorefineries. Here, we develop quantitative insights into the relationship between bioproduct market value and target accumulation rates by investigating a set of industrially relevant compounds already extracted from plant sources with a wide range of market prices and applications, including $100/kg (artemisinin). These compounds are used to identify a range of mass fraction thresholds required to achieve net economic benefits for biorefineries and the additional amounts needed to reach a target $2.50/gal biofuel selling price, using cellulosic ethanol production as a test case. Bioproduct market prices and recovery costs determine the accumulation threshold; we find that moderate- to high-value compounds (i.e., cannabidiol and artemisinin) offer net economic benefits at accumulation rates of just 0.01% dry weight (dwt) to 0.02 dwt%. Lower-value compounds, including limonene, latex, and PHB, require at least an order-of-magnitude greater accumulation to overcome additional extraction and recovery costs (0.3 to 1.2 dwt%). We also find that a diversified approach is critical. For example, global artemisinin demand could be met with fewer than 10 biorefineries, while global demand for latex is equivalent to nearly 180 facilities. Our results provide a roadmap for future plant metabolic engineering efforts aimed at increasing the value derived from bioenergy crops.

The investigation of fuel cell vehicles (FCVs) connected to grid (FCV2G) technology regarding the reduction of consumer costs is proposed. Herein, the key contribution is to investigate the energy and profit analysis aspects of an FCV2G system supported by photovoltaic (PV) panels for a 24 h operation. For this, an FCV in the rating of 100 kW is connected to the grid/homes, and a detailed analysis is performed for the FCV2G system supported by PV energy in the rating of 40 kW. The designed system is primarily tested for energy transfer from FCV/PV to grid/homes, and the results are verified for dynamic loading situations. It is observed that FCV + PV supply excess power to the grid during flexible hours of the day, and consumer homes use additional energy from the grid during peak hours. The profit analysis of the established FCV2G system is conducted using the load profile data for the 24 h situation. FCV2G supported by a PV system verifies that the homes' consumption cost is reduced significantly, and the remaining energy is utilized by selling the energy to the grid. [ABSTRACT FROM AUTHOR]

Cellulosic biomass shows great potential as feedstock for bioethanol production. Despite clear benefits in terms of greenhouse gas mitigation and bioproduct potential, the commercial production of cellulosic ethanol remains economically challenging at the current state of technology. This paper presents a technoeconomic analysis of a fungal pretreatment-based cellulosic ethanol plant with a processing capacity of 2000 tonnes of switchgrass per day. The production process model was designed and simulated using SuperPro Designer. The plant's ethanol yield, capital investment per unit capacity, and unit ethanol production cost were estimated to be 211.90 L/t of switchgrass, $ 3.60/L, and $ 1.44/L of ethanol, respectively. Fungal pretreatment was the major contributor (72%) to the total capital investment, mainly due to the large quantity of equipment required in the process. A positive net present value (NPV) was generated for the baseline model at ethanol selling price of $ 1.50/L, which increased by 5-fold for 80% glucose yield. Glucose yield was the most sensitive to NPV for all the process parameters evaluated.

The rational management of water, which is determined by the Framework Directive 2000/60/EC of the EU, is a contractual obligation of the Agricultural Sector of Cyprus, both towards the European Union and the next generations of Cypriot citizens. To make decisions about sustainable water use and improve water use, it is necessary to understand the water use of crops in different water-use areas. Especially in large water projects in Cyprus, there must be a good way to determine the water use of crops so that the correct use of crops can be ensured, thus eliminating problems such as a lack of new information about the crop area and agricultural evaporation, Demand, and water. In most projects, water is managed and supplied based on historical data, and current information is available to determine water demand and availability for large areas. This paper also adds, apart from the clear positive effect of remote sensing and new technologies in crop irrigation, to the emerging need for advisory services for the diffusion of innovation to Cypriot farmers since the estimation of crop water requirements is part of estimating the carbon footprint under the project CARBONICA (EU Funded) for carbon farming.

The photocatalytic decomposition of atmospheric methane (CH _4 ) and nitrous oxide (N _2 O) could be valuable tools for mitigating climate change; however, to date, few photocatalyst deployment strategies have had their costs modeled. Here, we construct basic cost models of three photocatalytic CH _4 and N _2 O decomposition systems: (1) a ground-based solar system with natural airflow over photocatalyst-painted rooftops, (2) a ground-based LED-lit system with fan-driven airflow, and (3) an aerosol-based solar system on solid particles dispersed in the atmosphere. Each model takes as inputs the photocatalyst’s apparent quantum yield (AQY; a measure of how efficiently photons drive a desired chemical reaction) and the local CH _4 or N _2 O concentration. Each model calculates an overall rate of greenhouse gas (GHG) drawdown and returns a levelized cost of GHG removal per equivalent ton of carbon dioxide (tCO _2 e). Based on prior studies of atmospheric carbon dioxide removal, we adopt $100/tCO _2 e as a target cost. We estimate that painting rooftops with photocatalysts might meet the target cost for decomposition of >10 ppm CH _4 with catalyst AQYs >4%. If painting and cleaning costs were reduced by a factor of ∼3 from our scenario, removal of ambient CH _4 could meet the cost target with AQYs >1% and removal of ambient N _2 O could do so with AQYs >0.1%. Fan-driven systems with LED illumination appear to be very challenging, achieving removal costs 10% for CH _4 and >1% for N _2 O. Dispersing photocatalytic aerosols in the troposphere could be cost-effective with AQYs of >0.4% for ambient CH _4 or >0.04% for ambient N _2 O. However, the mass of aerosols required is large and their side effects and social acceptability are uncertain. We note that, for any system, AQYs on the order of 1% will likely be extremely challenging to achieve with such dilute reagents.

The future bioeconomy promises drop-in or performance-advantaged biofuels and bioproducts derived from lignocellulosic biomass, substantial greenhouse gas emissions reductions in sectors with few or no alternatives, and increased domestic energy production in countries with sufficient biomass resources. Despite the slower than anticipated pace of commercializing next-generation biofuels, the research community continues to make dramatic improvements at every stage of production, from feedstock cultivation through conversion to final products. However, the interdisciplinary nature of bioenergy research, and the need for cross-coordination among biologists, chemists, agronomists, and engineers, make coordinating and optimizing these strategies challenging. This Perspective surveys recent advancements in bioenergy crop engineering, lignocellulosic biomass deconstruction and fractionation, catabolism of biomass-derived sugars and aromatics, and biological conversion to fuels and products. We organize major research approaches into broad categories and comment on which strategies offer synergies or trade-offs in the context of four approaches to improving the economics and carbon-efficiency of advanced biofuels and bioproducts: (1) maximize sugar conversion to a single product, (2) utilize diverse carbon sources for producing a single product, (3) convert lignin to high-value products, and (4) fractionate the hydrolysate to derive maximum value from each component.

Some lessons learned from the EU project “Broadband e-Services and Access to the Home” (2005–2007) are presented concerning the broadband development in rural ar- eas. In particular, the paper discusses the common problems of broadband deployment in the rural environment, various aspects of stimulating demand for broadband, the limitations of public aid and, most importantly, the problems of technoeconomic analysis

The resource endowment structure of being coal-rich and oil-poor makes China's production of coal-based ammonia and urea, with a low production cost and a good market, a competitive advantage. However, the process suffers from high CO2 emissions and low energy efficiency and carbon utilization efficiency due to the mismatch of hydrogen-to-carbon ratio between raw coal and chemicals. Based on the coal-to-urea (CTU) process and coal-based chemical looping technology for urea production processes (CTUCLAS&H), a novel urea synthesis process from a coal and coke-oven gas-based co-feed chemical looping system (COG-CTUCLAS&H) is proposed in this paper. By integrating chemical looping air separation and chemical looping hydrogen production technologies and the synergies between coal gasification, low-energy consumption CO2 capture and CO2 utilization are realized; the excess carbon emissions of the CTU process are avoided through coupling the pressure swing adsorption of COG, and the low carbon emissions of the proposed system are obtained. In this work, the novel process is studied from three aspects: key unit modeling, parameter optimization, and technical-economic evaluation. The results show that COG-CTUCLAS&H achieves the highest system energy efficiency (77.10%), which is much higher than that of the CTU and CTUCLAS&H processes by 40.03% and 32.80%, respectively, when the optimized ratio of COG to coal gasified gas is 1.2. The carbon utilization efficiency increases from 35.67% to 78.94%. The product cost of COG-CTUCLAS&H is increased compared to CTU and CTUCLAS&H, mainly because of the introduction of COG, but the technical performance advantages of COG-CTUCLAS&H make its economic benefits obvious, and the internal rate of return of COG-CTUCLAS&H is 26%, which is larger than the 14% and 16% of CTU and CTUCLAS&H, respectively. This analysis will enable a newly promising direction of coal and COG-based co-feed integrated chemical looping technology for urea production. [ABSTRACT FROM AUTHOR]

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