Cleaner Production Research Articles

Effects of the U.S. inflation reduction act on SMR economics

The U.S. Inflation Reduction Act (IRA) of 2022 provides a wide array of tax credits and other incentives for low-carbon energy. The technology-neutral clean generation production tax credit (PTC) (Section 45Y of the U.S. Internal Revenue Code) and the technology-neutral investment tax credit (ITC) (Section 48E) lower the net cost of new electricity generation projects with zero or negative greenhouse gas emission rates. We evaluate the impact of the IRA legislation—specifically the PTC and ITC—on the cost-competitiveness of small modular reactors (SMRs). We use the Argonne Low-carbon Energy Analysis Framework (A-LEAF) model to calculate the capacity factor of an SMR with a range of hypothetical variable operating and maintenance (O&M) costs in the Electric Reliability Council of Texas (ERCOT) electricity market. We selected ERCOT for market modeling because of its competitive structure, available data, and extensive use in prior literature. We use a discounted cash flow model to calculate the SMR’s net present value based on the market prices and capacity factors from A-LEAF, hypothetical ranges of capital and variable O&M costs, and other input parameters, with or without the IRA tax credits. We determine the SMR owner’s optimal choice of PTC or ITC for the hypothetical ranges of capital and variable O&M costs. We also evaluate potential shifts in the SMR owner’s optimal choice of PTC or ITC based on historical patterns of nuclear capital cost overruns in the United States. We also assess the sensitivity of our results to longer PTC period and electricity prices from the New England market, which tend to be higher than electricity prices in ERCOT. We find that even with the IRA tax credits, only SMRs with low capital and variable O&M costs would be economically feasible in the low-price ERCOT market scenario modeled. A longer PTC period and higher-price market such as New England, however, would significantly expand the economic feasibility of SMRs in the United States.

Use of whey protein concentrate to encapsulate hydrophobic natural antimicrobials to improve their incorporation into high moisture foods enhancing their antimicrobial activity

Synthetic antimicrobials have been questioned by consumers; thus, natural antimicrobials have emerged as an alternative. However, their use is limited by their low miscibility in high-moisture foods. The objective of this work was to formulate and characterize microparticles of cinnamaldehyde (E-CIN) and vanillin (E-VA) using whey protein concentrate (WPC), and to assess the effect of the encapsulation on the inactivation of L. innocua in a protein beverage. The concentration of WPC (1:1 or 2:1) in the E-CIN did not affect the droplet size and stability, thus the 1:1 ratio was selected. On the contrary, in E-VA increasing WPC concentration (2:1) reduced the droplet size, increasing stability. E-CIN presented greater antimicrobial activity than the unemulsified CIN. E-CIN (1.0 g/L) showed the greatest antimicrobial activity with 3.5 log cycles reduction of L. innocua. While vanillin encapsulation had an insignificant effect on the antimicrobial activity, reducing 1.0 log cycles of L. innocua. In conclusion, cinnamaldehyde was more effective than vanillin, and the encapsulation with WPC increased its antimicrobial activity. Further research is necessary to improve the stability and the antimicrobial activity of vanillin microparticles. Industrial relevanceThis work proposes an alternative to replace synthetic antimicrobials with natural antimicrobials of plant origin. It is based on solving the problem of the low miscibility of hydrophobic antimicrobials such as cinnamaldehyde (cinnamon oil) and vanillin, to incorporate them into foods with high moisture content. This information could be useful for the beverage and juice industry, as encapsulated natural antimicrobials can be used to obtain high-quality, fresh, clean label products. Additionally, extending the shelf life of the product can be advantageous for commercialization purposes.

China’s ecological footprint via biomass import and consumption is increasing

As China’s economic and population demands grow, the need for biomass imports rises, presenting challenges for sustainable development and global ecosystem protection. Here we examine China’s increasing influence on global ecosystems through its biomass product consumption and trade using the Human Appropriation of Net Primary Productivity framework, analyzing data from 2004 to 2017 with projections until 2050. In 2017, China was the world’s largest biomass consumer, consuming approximately 1.75 petagrams of carbon per year, projected to rise by 317.6% by 2050, highlighting China’s major role in global ecosystem stress. Our findings also show an increase in biomass imports from lower-middle-income and low-income countries between 2004 and 2017, and these imports are expected to continue increasing by 402.9% in 2050. The analysis reveals that domestic product demand and changes in foreign production efficiency are key drivers of this trend, suggesting the need for China to shift towards more efficient trade practices and support cleaner production methods internationally.

Metal Sulfide‐Based Nanoarchitectures for Energetic and Environmental Applications

Despite their numerous excellent properties, metal sulfides are not particularly efficient at converting energy and purifying the environment, which limits their further applications. Fortunately, the energy conversion and environmental purification efficiencies of these materials have experienced notable advancements in recent years, accompanied by an improved understanding of their underlying mechanisms. Herein, progress in experimental researches in recent years on the engineering of single component metal sulfides by controlling morphology, construction of heterojunctions, and incorporating elements is reviewed. Methods to design and prepare metal sulfide‐based composites by building binary or ternary heterojunctions of metal sulfide/semiconductor/conductor are also discussed in detail. These materials are used in energy conversion and environmental purification systems, where they act as photocatalytic materials not only to split water, reduce carbon dioxide or nitrogen, but also to degrade pollutants (organic and inorganic) in water and gas. Finally, it is concluded by summarizing the research frontiers of metal sulfide nanomaterials in energy and environmental applications, as well as proposing potential challenges and future research directions. This work may contribute to a better understanding of metal sulfide nanocomposites and provide clues for the fabrication of more efficient metal sulfide‐based nanostructures for clean energy production and environmental remediation.

Integrated Heterogeneous Engineering with the Vacancy Defect of Porous CoPv-MoxPv Nanosheets for an Accelerated Hydrogen Evolution Reaction.

Electrochemical water splitting is a possible way of realizing sustainable and clean hydrogen production but is challenging, because a highly active and durable electrocatalyst is essential. In this work, we integrated heterogeneous engineering and vacancy defect strategies to design and fabricate a heterostructure electrocatalyst (CoPv-MoxPv/CNT) with abundant phosphorus vacancies attached to carbon nanotubes (CNTs). The vacancy defects enabled the optimization of the electronic structure; thereby, the electron-rich low-valent metal sites enhanced the ability of nonmetallic P to capture proton H. Meanwhile, the heterogeneous interface between bimetallic phosphides and CNTs realized rapid electron transfer. In addition, the Co, Mo, and P active species in the electrocatalytic process exposed increased amounts of active sites featuring porous nanosheet structures, which facilitated the adsorption of reaction intermediates and thus enhanced the hydrogen evolution reaction performance. In particular, the optimized CoPv-MoxPv/CNT catalyst possesses an overpotential of 138 mV at a current density of 10 mA cm-2 and long-term stability for 24 h. This work offers insights and possibilities for the engineering and exploration of transition metal-based electrocatalysts through combining multiple synergistic strategies.

Scalable fabrication of collagen fiber-waterborne polyurethane foams with enhanced toughness and thermal insulation by constructing energy dissipation networks

Natural fiber-based foams demonstrate outstanding potential for energy-efficient building and personal protective equipment applications due to their lightweight, high porosity, and sustainability. However, the weak interfacial interaction among fibers, functional additives, and the matrix hampers effective stress dissipation, largely affecting the material performance. Herein, this paper demonstrates a facile strategy for fabricating high-performance collagen fiber-based foams by constructing efficient energy dissipation networks using tannin-modified leather collagen fibers (T-LCF) and waterborne polyurethane (WPU). Tannin acts as a coupling bridge, linking the fiber and polyurethane to create a hydrogen-bonded network, enhancing energy dissipation and imparting excellent mechanical properties. Compared to WPU foam (WPUF), the T-LCF-based foam (WPUF/T-LCF) showed 65%, 34 times, and 35% improvements in tensile strength, compressive strength, and ultimate oxygen index, respectively. This study provides new insights into the cleaner production of high-performance natural fiber-based foam composites and a new way for the high-value utilization of collagen solid waste.

Effects of Controlled-release Blended Fertilizer on Crop Yield and Greenhouse Gas Emissions in Wheat-maize Rotation System

The increasing use of nitrogen fertilizers exerts extreme pressure on the environment (e.g., greenhouse gas emissions, GHGs) for winter wheat-summer maize rotation systems in the North China Plain. The application of controlled-release fertilizers is considered as an effective measure to improve crop yield and nitrogen fertilizer utilization efficiency. To explore the impact of one-time fertilization of controlled-release blended fertilizer on crop yield and GHGs of a wheat-maize rotation system, field experiments were carried out in Dezhou Modern Agricultural Science and Technology Park from 2020 to 2022. Five treatments were established for both winter wheat and summer maize, including no nitrogen control (CK), farmers' conventional nitrogen application (FFP), optimized nitrogen application (OPT), CRU1 (the blending ratio of coated urea and traditional urea on winter wheat and summer maize was 5:5 and 3:7, respectively), and CRU2 (the blending ratio of coated urea and traditional urea on winter wheat and summer maize was 7:3 and 5:5, respectively). The differences in yield, nitrogen fertilizer utilization efficiency, fertilization economic benefits, and GHGs among different treatments were compared and analyzed. The results showed that nitrogen application significantly increased the single season and annual crop yields of the wheat-maize rotation system (P < 0.05). Compared with those of FFP, the CRU1 and CRU2 treatments increased the yields of summer maize by 0.4% to 5.6%, winter wheat by -5.4% to 4.1%, and annual yields by -1.1% to 3.9% (P > 0.05). N recovery efficiency (NRE), N agronomic efficiency (NAE), and N partial factor productivity (NPFP) were increased by -8.6%-43.4%, 2.05-6.24 kg·kg-1, and 4.24-10.13 kg·kg-1, respectively. Annual net income increased by 0.2% to 6.3%. Nitrogen application significantly increased the annual emissions of soil N2O and CO2 in the rotation system (P < 0.05) but had no effect on the annual emissions of CH4 (except for in the FFP treatment in the first year). The annual total N2O emissions under the CRU1 and CRU2 treatments were significantly reduced by 23.4% to 30.2% compared to those under the FFP treatment (P < 0.05). Additionally, nitrogen application significantly increased the annual global warming potential (GWP) of the rotation system (P < 0.05), but the intensity of greenhouse gas emissions was reduced due to the increase in crop yields. Compared with that under FFP, the annual GWP under the CRU1 and CRU2 treatments decreased by 9.6% to 11.5% (P < 0.05), and the annual GHGs decreased by 11.2% to 13.8% (P > 0.05). In summary, the one-time application of controlled-release blended fertilizer had a positive role in improving crop yield and economic benefits, reducing nitrogen fertilizer input and labor costs, and GHGs, which is an effective nitrogen fertilizer management measure to promote cleaner production of food crops in the North China Plain.

Shaping the Future of Environmental Economics: A Bibliometric Review of Current Trends and Future Directions

Environmental economics is increasingly pivotal in addressing global environmental challenges. This study aims to elucidate the research landscape in this field, focusing on prevalent themes such as climate change, carbon emissions, sustainable development, and environmental policy. Employing a bibliometric analysis, we analyzed a substantial corpus of literature from Scopus. We applied Lotka's Law to assess author productivity and distribution and conducted institutional and country-level analyses to map the geographical spread and institutional affiliations in environmental economics research. Our analysis highlights a significant growth in the environmental economics literature, with a notable focus on climate change and sustainability. A concentration of publications among a few authors was observed, indicating influential researchers and potential for increased collaboration. The rise in publications, particularly in China and leading journals like 'The Journal of Cleaner Production,' reflects a global upsurge in environmental economics research. Distinct clusters were identified, covering diverse topics from climate change economics to environmental policy. The study acknowledges limitations due to exclusive reliance on Scopus data, suggesting future research to include other databases like the Web of Science for a more comprehensive analysis. Considering the evolving nature of environmental challenges, we advocate for interdisciplinary approaches and continual updates in research to address emergent trends in this critical field.

Innovations in Electric Current-Assisted Sintering for SOFC: A Review of Advances in Flash Sintering and Ultrafast High-Temperature Sintering

This review discusses the groundbreaking advancements in electric current-assisted sintering techniques, specifically Flash Sintering (FS) and Ultrafast High-Temperature Sintering (UHS), for their application in Solid Oxide Fuel Cells (SOFCs). These innovative sintering methods have demonstrated remarkable potential in enhancing the efficiency and quality of SOFC manufacturing by significantly lowering sintering temperatures and durations, thereby mitigating energy consumption and cost. By providing a detailed overview of the mechanisms, process parameters, and material characteristics associated with FS and UHS, this paper sheds light on their pivotal role in the fabrication of SOFC components such as electrolytes, electrodes, multilayered materials, and interconnect coatings. The advantages, challenges, and prospective opportunities of these sintering technologies in propelling SOFC advancements are thoroughly assessed, underlining their transformative impact on the future of clean and efficient energy production technologies.

Artisanal and small-scale gold mining and biodiversity: a global literature review.

Artisanal and small-scale gold mining (ASGM) is crucial to the livelihoods of close to 20 million people in over 80 countries, including 4-5 million women, mainly in rural areas with limited alternative economic prospects, particularly in developing countries. ASGM is largely informal, which can add to the challenge of addressing negative social and environmental effects including impacts on biodiversity. However, with proper guidance, ASGM can operate in a responsible manner, using cleaner production methods that minimize impacts on human health and the environment. This study presents and analyzes the interactions between ASGM and biodiversity based on new findings from 27 ASGM National Action Plans (NAPs) developed within the framework of Article 7 and Annex C of the Minamata Convention on Mercury, as well as a global literature review of more than 100 publications. In terms of key findings according to the literature reviewed, alongside other human occupation such as agriculture and industrial activities, ASGM also has an impact on the environment and biodiversity. The interrelationship between ASGM and biodiversity, including protected areas, is pervasive at every stage of ASGM operations, from extraction to mine closure, and generates significant impacts on the surrounding ecosystems. These impacts include, in descending order of most reported impacts: deforestation, soil degradation, chemical contamination of aquatic and terrestrial systems, and changes to the turbidity of watercourses. Tropical regions and key species such as amphibians and freshwater fish are among the most affected. Singly or combined, these environmental stressors lead to loss or deterioration of habitat and, by extension, indigenous biodiversity and ecosystem services. In addition, legal, institutional, and regulatory frameworks and related measures, inadequate or non-existent in some cases, may not necessarily support sustainable practices, often resulting in exploited sites abandoned without remediation, reclamation, rehabilitation, or restoration measures. To mitigate such impacts a key recommendation arising from the literature review is to strengthen the integration of the interrelationship between ASGM and biodiversity in the implementation of existing relevant national strategies, including those developed under the NAPs. The global literature review also highlights the importance of a multi-stakeholder, systemic approach combining the use of geospatial analysis, scientific and local knowledge, as well as the adaptation of the relevant frameworks, capacity building, and awareness raising. This approach can inform decision making with a view to developing sustainable initiatives that prevent and reduce the impacts of artisanal and small-scale gold mining on ecosystems, and that preserve biodiversity.

Development of bioactive films loaded with extract and polysaccharide of Pinus brutia bark.

Society's interest in natural and clean products in many areas, such as food and cosmetics, has increased considerably. It has led to the development of new techniques in the packaging of products so that the wastes from the preferred products can be recycled. In this context, Pinus brutia bark was preferred within the scope of the study to transform natural wastes into functional components and use them as packaging material. P. brutia bark (PBB) samples were collected from Bursa, Turkey. PBB samples were ultrasonically extracted using various solvents (acetone, butanol, ethanol, ethyl acetate, hexane, methanol, petroleum ether, and water) and a solvent-acidic hydrolysis system. The phenolic content profile of PBB samples was determined using high-performance liquid chromatography with diode-array detection, and total flavonoid content, antioxidant capacity, and total phenolic content were determined. Chitosan-polyvinyl alcohol (CS-PVA) films loaded with polysaccharides and containing methanolic extract were developed. The physical, chemical, and mechanical properties of the films were characterized. It is known that the thickness of the films determines the mechanical properties required to maintain the integrity of the packaging during storage and transport. From the results of the study, it was concluded that the elongation at break value was higher in CS-PVA-PBB-M films (111.08%±10.46%), Young's modulus (31.74±21.37N/mm2), and tensile strength (3.01±0.50N/mm2) values were higher in CS-PVA films. In this case, it was concluded that adding proanthocyanidin to edible films gives flexibility to the films.

Boosting photocatalytic activity in ternary lamellar hierarchical structured ZnFe2O4/polymeric carbon nitride by constructing an electronic bridge

Photocatalytic technology is one of the ideal approaches for clean energy production and environmental pollution control in the future. However, the rapid recombination of photo-generated charge carriers is a bottleneck problem of low solar energy conversion efficiency. Herein, a magnetic ZnFe2O4/Pt/polymeric carbon nitride (PCN) semiconductor catalyst is designed and prepared for high-performance photocatalytic hydrogen production reaction and photocatalytic degradation rate of RhB. It exhibits 339.31 μmol·g−1·h−1 hydrogen production rate and 96.08 % photocatalytic degradation rate of RhB within 120 min under visible light. The introduction of Pt, constructing an electronic bridge, accelerated the transfer of photo-generated carriers, meanwhile, the smaller band gap of the ternary composites enabled the generation of more photo-generated electrons. The internal electric field accelerated the accumulation of electrons and holes in the conduction band of ZnFe2O4 and valence band of PCN, thus photocatalytic activity is greatly enhanced. The electron-hole separation is also improved and the transport of photo-generated electrons is facilitated by the special structure of the heterojunction and the unique morphology of PCN. In addition, the used catalyst can be recovered through magnetic fields, and this magnetic catalytic system has great application prospects in the fields of photocatalytic hydrogen production and pollutant degradation.

An assessment of current hydrogen supply chains in the Gulf Cooperation Council (GCC)

The Gulf Cooperation Council (GCC), comprising: Saudi Arabia, United Arab Emirates, Kuwait, Qatar, Oman, and Bahrain, is home to an abundant number of resources, including natural gas and solar and wind energy (renewables). Because of this, the region is favourably positioned to become a significant player in both blue and green hydrogen production and their export. Current dependence on fossil fuels and ambitious national targets for decarbonisation have led the region and world to research the feasibility of switching to a hydrogen economy. This literature review critically examines the current advantages and strategies adopted by the GCC to expedite the implementation of hydrogen supply chains, as well as investigation into the methodologies employed in current research for the modelling and optimisation of hydrogen supply chains. Insight into these endeavours is critical for stakeholders to assess the inherent challenges and opportunities in establishing a sustainable hydrogen economy. Despite a substantial global effort, establishing a solid hydrogen supply chain presently faces various obstacles, including the costs of clean hydrogen production. Scaling-up storage and transport methods is an issue that affects all types of hydrogen, including carbon-intensive (grey) hydrogen. However, the current costs of green hydrogen production, mostly via the process of electrolysis, is a major obstacle hindering the widescale deployment of clean hydrogen. Research in this literature review found that compressed gas and cryogenic liquid options have the highest storage capacities for hydrogen of 39.2 and 70.9 kg/m3, respectively. Meanwhile, for hydrogen transportation, pipelines and cryogenic tankers are the most conventional and efficient options, with an efficiency of over 99 %. Cryogenic ships to carry liquid hydrogen also show potential due to their large storage capacities of 10,000 tonnes per shipment, However, costs per vessel are currently still very expensive, ranging between $ 465 and $620 million.

Reducing carbon emissions in prefabricated buildings supply chains: a focus on component manufacturing processes.

The construction sector accounts for 23% of emissions from global economic activity, with China responsible for nearly 41%. Although China has vigorously promoted the development of prefabricated buildings (PBS) in pursuit of cleaner production, the carbon emissions from prefabricated component factories (PCF) should not be underestimated. So, the focus of this research was on how to promote the decarbonization of PCF. Based on the carbon trading market mechanism, the carbon emissions trading tax and revenue tax collection, the authors established a differential game model consisting of the local government and the PCF, studied the equilibrium solutions under different decision models, and analyzed the roles of the two tax systems, carbon trading revenue, and market preferences. The results are as follows: (1) The PCF's low-carbon technology (LCT) innovation efforts can be directly affected by the carbon price, component price, and tax rate and indirectly affected by influencing the local government's efforts. Besides, the local government and the PCF strategies can be changed through the central government's regulation of carbon prices and tax rates. (2) PCF should set reasonable prices for components, improving economic efficiency and the LCT stocks. (3) Cost-sharing contracts can encourage PCF to increase their LCT innovation, which is conducive to increasing the optimal benefits of the PCF. (4) The local government cannot be motivated by cost-sharing contracts. They can increase their optimal benefits only if the cost-sharing coefficient is below a threshold or if the environmental benefits from low-carbon production are above a specific value.

Fabrication of hydrophobic surface from zein-based nanostructure and rosin to functionalize cotton textiles

A double-layer hydrophobic coating based on zein nanoparticles (ZNPs) and rosin was successfully developed as a simple and non-toxic process for textile functionalization. The bottom layer of the coating was a highly rough surface formed by the accumulation of zein nanoparticles prepared with an antisolvent method. The top layer was made of rosin to reduce the surface energy. The fabric treated with ZNPs and rosin (ZNPs/R/cotton) exhibited good hydrophobic behavior with a water contact angle (WCA) of 131.5 ± 2.3° and the hydrophobicity was long-lasting. The micromorphology and chemical composition of hydrophobic cotton fabric surface were characterized by scanning electron microscopy (SEM) and infrared spectroscopy (FTIR), respectively. The results demonstrated that zein and rosin deposited on the surface of the fabric to form a rough micro/nano-scale structure. The functional ZNPs/R/cotton retained excellent mechanical properties, air permeability and water vapor permeability. The practical application tests indicated that the fabric displayed good stain resistance ability. Even after 10 soaking cycles and 50 rubbing cycles, the fabric still retained good hydrophobic property with WCAs of 124.7 ± 2.9° and 90.3 ± 3.5°. This work offered a potential method for the clean production of functionalized textiles.

Grain boundary defect engineering in rutile iridium oxide boosts efficient and stable acidic water oxidation.

PEMWEis considered a promising technology for coupling with renewable energy sources to achieve clean hydrogen production. However, constrained by the sluggish kinetics of the anodic OERand the acidic abominable environment render the grand challenges in developing the active and stable OER electrocatalyst, leading to low efficiency of PEMWE. Herein, we develop the rutile-type IrO2 nanoparticles with abundant grain boundaries and the continuous nanostructure through the joule heating and sacrificial template method. DFT calculations verified that grain boundaries can modulate the electronic structure of Ir sites and optimize the adsorption of oxygen intermediates, resulting in the accelerated kinetics. The 350-IrO2affords a rapid OER process with 20 times higher mass activity (0.61 A mgIr-1) than the commercial IrO2 at 1.50 V vs. RHE. Benefiting from the reduced overpotential and the preservation of the stable rutile structure, 350-IrO2 exhibits the stability of 200 h test at 10 mA cm-2 with only trace decay of 11.8 mV. Moreover, the assembled PEMWE with anode 350-IrO2 catalyst outputs the current density up to 2 A cm-2 with only 1.84 V applied voltage, long-term operation for 100 h without obvious performance degradation at 1 A cm-2.

A comprehensive review on unleashing the power of hydrogen: revolutionizing energy systems for a sustainable future.

Population growth and environmental degradation are major concerns for sustainable development worldwide. Hydrogen is a clean and eco-friendly alternative to fossil fuels, with a heating value almost three times higher than other fossil fuels. It also has a clean production process, which helps to reduce the emission of hazardous pollutants and save the environment. Among the various production methodologies described in this review, biochemical production of hydrogen is considered more suitable as it uses waste organic matter instead of fossil fuels. This technology not only produces clean energy but also helps to manage waste more efficiently. However, the production of hydrogen obtained from this method is currently more expensive due to its early stage of development. Nevertheless, various research projects are underway to develop this method on a commercial scale.

Unlocking the potential of depleted dry batteries: A dual-purpose approach for waste mitigation and sustainable energy production

Electronic-waste (e-waste) poses a serious environmental challenge due to the increasing consumption and disposal of electronic devices. In the present work a novel method is proposed to repurpose e-waste and bio-waste into a single-chamber and mediator-less microbial fuel cells using dead, non-rechargeable D-type dry batteries. The carbonaceous material inside the dry batteries was replaced with kitchen waste sludge, which served as the substrate. The outer zinc casing was also reused as the anode and the carbon rod as the cathode. Treating the kitchen waste sludge with dilute nitric acid improved the performance of the microbial fuel cells by enhancing the biodegradability and conductivity of the substrate. The untreated microbial fuel cells produced a maximum power density of 15.0 mW/kg at a maximum current density of 50.0 mA/kg, while the treated microbial fuel cells achieved 67.0 mW/kg at 178.0 mA/kg. The main mechanism behind the working of the device is the combined action of galvanic and microbial processes, which synergistically generate electricity from e-waste and bio-waste. Moreover, when four treated microbial fuel cells were connected in series, a high open circuit voltage of 3.3 V was achieved. These microbial fuel cells stand out as eco-conscious and lightweight alternatives to conventional dry batteries, presenting an environmentally sustainable solution for waste management and clean energy production.

Reactive liquid-liquid extraction of lactic acid from microfiltered sweet sorghum silage press juice in an agitated extraction column using a hydrophobic natural deep eutectic solvent as modifier

Downstream processing of carboxylic acids from fermentation broths is cost-intensive and environmentally harmful, which makes methods such as reactive liquid-liquid extraction attractive separation technologies. To enhance the sustainability of liquid-liquid extraction processes, research focuses on sustainable solvents like hydrophobic natural deep eutectic solvents. However, the application of hydrophobic natural deep eutectic solvents in agitated extraction columns for continuous processing has never been investigated. This is essential to facilitate their use in industrial processes, promoting cleaner production. In this study, the application of a thymol-menthol-based deep eutectic solvent as a modifier (with the extractant tri-n-octylamine) in an agitated extraction column is evaluated for reactive liquid-liquid extraction of lactic acid from microfiltered sweet sorghum silage press juice. In addition, three-stage cross-current extractions were performed. The thymol-menthol-based deep eutectic solvent showed efficient phase separation, stable operation, and chemical stability in the agitated extraction column. In three-step cross-current operation, the extraction efficiency for lactic acid was increased from 37.0 ± 0.4 % without feed pH adjustment to 76.2 ± 0.9 % with continuously adjusting the pH value to 2.05 ± 0.02. The thymol-menthol-based deep eutectic solvent shows great potential for application in agitated extraction columns. This is highly promising because natural deep eutectic solvents can enhance the sustainability of extraction processes and reduce the reliance on fossil-based solvents.

A numerical simulation and analysis of chalcogenide BaZrS3-based perovskite solar cells utilizing different hole transport materials

Recently, barium zirconium sulfide (BaZrS3) chalcogenide perovskite (CP) material has attracted much attention in the photovoltaic community because of its excellent light harvesting ability, stability, and nontoxicity. BaZrS3 has shown great potential in becoming the best alternative to hybrid halide perovskites. Herein, we have numerically simulated and optimized the performance of a device with the general architecture FTO/WS2/BaZrS3/HTL/Au, using SCAPS-1D (version 3.3.07) software. In this general device, inorganic CuSCN, Cu2O and organic poly(3-hexylthiophene) (P3HT) were inserted, and performance was evaluated as hole transport layer (HTL) materials. Moreover, the influence of various parameters on the device, such as the effect of changing the absorber defect density, varying the operation temperature, and using different metal back contacts, were examined. The best HTL material was organic P3HT, and it exhibited a power conversion efficiency (PCE) of 13.86 %, with a Fill factor (FF) of 11.97 %, open circuit voltage (Voc) of 6.58 V, and current density (Jsc) of 17.59 mA cm−2. The other tested inorganic CuSCN and Cu2O HTL showed a PCE of 13.83 and 13.70 %, respectively. For all the devices, the optimum density of defects was kept at 1.0 × 1015 cm−2. It was established that the P3HT-based device can operate and be stable between 240–––340 K temperature window, while devices with CuSCN and Cu2O can work between 280 – 400 K temperature range. Thus, the CuSCN- and Cu2O-based devices were more stable because they could form a more compact structure that can withstand relatively higher operation temperatures than organic-based devices with P3HT as HTL. Finally, it was established that relatively cheaper metals such as Pt, Ni, and Pd can be suitable alternatives to expensive gold metal back contact. It is expected that this work would shed additional light on the utilisation of BaZrS3 as a promising absorber material in the actual manufacturing of solar cells for clean energy production.