Excessive Consumption Of Fossil Fuels Research Articles

Enhancement of CO2 Adsorption Kinetics onto Carbon by Low-Frequency High Amplitude Resonant Vibrations

Due to the excessive consumption of fossil fuels, which leads to significant greenhouse gas emissions and rapid climate change, it is crucial to develop various carbon capture and sequestration strategies. CO2 sequestration in solid, porous adsorbents like low-cost biochar has emerged as a promising approach to achieve this goal. However, slow adsorption kinetics are one of the issues that limit the widespread use of this approach. While the characteristics of the biochar are important and impact CO2 adsorption, the conditions under which adsorption occurs are equally critical. In this work, a novel strategy is proposed to accelerate the CO2 uptake rate on carbon adsorbents by utilizing Low-Frequency High Amplitude resonant vibratory mixing during the adsorption process. With this approach, the rate of adsorption (characterized by the adsorption rate constant) exhibits an increase of 46.6% and 91.3%, as calculated by two different kinetic models: the Weber and Morris model, and the Pseudo-First-Order model. Experimental observations indicate that adsorption kinetics have a mixed control between external/internal diffusion and the physisorption process. Resonant vibrations enhance system energy, promoting collisions between CO2 molecules and carbon surfaces, subsequently improving CO2 transport and surface/gas interactions, facilitating the adsorption process and thus leading to enhanced kinetic rates. Furthermore, an analysis of variance determined the sensitivity of CO2 uptake to several operating parameters associated with the resonant vibrations. This analysis indicated that the adsorption of CO2 is most sensitive to the level of fill of the adsorption vessel and the time exposed to resonant vibrations.

Interface engineering of BiVO4/Zn3V2O8 heterocatalysts for escalating the synergism: Impact of Cu electron mediator for overall water splitting

The risk of global warming is increasing due to excessive consumption of fossil fuels. To fill the gap between production and consumption of conventional energy sources, modern societies are searching green and renewable alternatives. In this work, BiVO4/Zn3V2O8 heterocatalysts were synthesized and interfacially engineered for overall water splitting reactions. To obtain the structural and interfacial morphologies, catalysts were characterized by XRD, FTIR, Raman spectroscopy, SEM and AFM techniques. The optical and chemical characteristics of as-synthesized catalysts were evaluated using UV–Vis/DRS, PL, EIS, EDX, XPS and BET analysis. The role of Cu metal, synergism between BiVO4/Zn3V2O8 and mechanistic approaches were further revealed. The results depict that Cu metal exceptionally compete to sustain the synergism as an electron mediator source. The synergistic effect and electron mediator were found as key factors to boost the overall water splitting efficiencies. Due to interfacial engineering of BiVO4/Zn3V2O8 system, charge transfer becomes more feasible for the redox reactions (i.e. water splitting). It was examined that due to presence of Cu metal, rate of overall water splitting reaction was higher than the catalysts having no mediator (i.e. absence of Cu). During photoreaction, two successive rates for H2 and O2 evolution were speculated 17.66 and 8.96 mmol g−1 h−1, respectively which delivers approximately 5.04 kJ g−1 h−1 energy. On the basis of results and activities, it could be concluded that, this research will exhibit exceptional potential and hold promise of an ultimate transition to the water splitting and green energy technologies.

Photoelectrochemical CO2 reduction with copper-based photocathodes

The excessive consumption of fossil fuels has led to a rapid surge in atmospheric CO2 concentration, triggering severe energy crises and environmental concerns. In this context, photoelectrochemical (PEC) technology for CO2 reduction is perceived as a highly appealing resolution, due to its integration of the advantages offered by both photocatalysis and electrocatalysis. Undoubtedly, the photocathode plays a pivotal role within the PEC CO2 reduction system. Among various catalysts, copper (Cu)-based photocathodes have garnered significant attention owing to their low toxicity, affordability, advantageous band gap and distinctive active sites that enable the conversion of CO2 into a diversity of reduction products including carbon monoxide (CO), formic acid (HCOOH), methane (CH4), ethylene (C2H4), ethanol (C2H5OH) and so on. This review primarily delves into the current developments of Cu-based photocathodes in PEC CO2 reduction, encompassing aspects like material fabrication processes and modification techniques. Subsequently, an analysis is presented regarding the reaction mechanisms underlying different CO2 conversion products. Finally, an anticipatory perspective is provided regarding future research in the field of PEC CO2 reduction. This review enables researchers to promptly capture the latest advancements of Cu-based photocathode for PEC CO2 reduction, offers valuable insights for future research on the design and synthesis of Cu-based photocathode, and provides a guideline to achieve enhanced improvements in PEC CO2 conversion.

Engineering extracellular electron transfer pathways of electroactive microorganisms by synthetic biology for energy and chemicals production.

The excessive consumption of fossil fuels causes massive emission of CO2, leading to climate deterioration and environmental pollution. The development of substitutes and sustainable energy sources to replace fossil fuels has become a worldwide priority. Bio-electrochemical systems (BESs), employing redox reactions of electroactive microorganisms (EAMs) on electrodes to achieve a meritorious combination of biocatalysis and electrocatalysis, provide a green and sustainable alternative approach for bioremediation, CO2 fixation, and energy and chemicals production. EAMs, including exoelectrogens and electrotrophs, perform extracellular electron transfer (EET) (i.e., outward and inward EET), respectively, to exchange energy with the environment, whose rate determines the efficiency and performance of BESs. Therefore, we review the synthetic biology strategies developed in the last decade for engineering EAMs to enhance the EET rate in cell-electrode interfaces for facilitating the production of electricity energy and value-added chemicals, which include (1) progress in genetic manipulation and editing tools to achieve the efficient regulation of gene expression, knockout, and knockdown of EAMs; (2) synthetic biological engineering strategies to enhance the outward EET of exoelectrogens to anodes for electricity power production and anodic electro-fermentation (AEF) for chemicals production, including (i) broadening and strengthening substrate utilization, (ii) increasing the intracellular releasable reducing equivalents, (iii) optimizing c-type cytochrome (c-Cyts) expression and maturation, (iv) enhancing conductive nanowire biosynthesis and modification, (v) promoting electron shuttle biosynthesis, secretion, and immobilization, (vi) engineering global regulators to promote EET rate, (vii) facilitating biofilm formation, and (viii) constructing cell-material hybrids; (3) the mechanisms of inward EET, CO2 fixation pathway, and engineering strategies for improving the inward EET of electrotrophic cells for CO2 reduction and chemical production, including (i) programming metabolic pathways of electrotrophs, (ii) rewiring bioelectrical circuits for enhancing inward EET, and (iii) constructing microbial (photo)electrosynthesis by cell-material hybridization; (4) perspectives on future challenges and opportunities for engineering EET to develop highly efficient BESs for sustainable energy and chemical production. We expect that this review will provide a theoretical basis for the future development of BESs in energy harvesting, CO2 fixation, and chemical synthesis.

Synergistic effect of ZnMgAl-hydrotalcite nanomaterials electrocatalysts on high efficiency electrocatalytic reduction of CO2 to CO

The excessive consumption of fossil fuels causes the increasing concentration of carbon dioxide (CO2) in the atmosphere. How to convert CO2 into various organic compounds and chemical fuels to promote the carbon cycle has become a hot issue in the forefront of science and technology in the world. In this paper, ZnMgAl-hydrotalcite (ZnxMg3-xAl-LDH, x=0, 1, 1.5, 2, 3) with different molar ratios of Zn, Mg and Al was prepared by hydrothermal synthesis method. Research results indicate that Zn1.5Mg1.5Al1-LDH with a molar ratio of n(Zn2+): n(Mg2+): n(Al3+) =1.5:1.5:1 on the layer of hydrotalcite has more appropriate metal ratio and arrangement, leading to the strongest synergistic effect among metals and demonstrating relatively optimal electrochemical performance. The Faraday efficiency of CO (FECO) preparation by CO2RR was up to 91.8% (-1.4V vs. RHE), which control the consumption within 9hours to less than 15%. The spin polarization density functional theory (DFT) method was used for calculation and structural analysis with the help of DMol3 module of Materials Studio. The results show that Zn1.5Mg1.5Al1-LDH has the lowest energy barrier of various reactions, the theoretical calculation results are consistent with the experimental results. Zn1.5Mg1.5Al1-LDH designed in this work has good catalytic activity and can be used for efficient electrocatalytic CO2 reduction to produce CO, realizing the resource utilization of CO2, and helping to improve the environmental problems caused by excessive CO2 emission. It provides a promising strategy for the environmental sciences to mitigate the effects of CO2.

Home Archives Vol. 44 No. S5 (2023) Articles Waste To Wonder: Production Of Bio-Diesel From Agri-Waste- A Comprehensive Review

In the contemporary era, the world is grappling with the challenges posed by the excessive consumption of fossil fuels and the degradation of the environment. The quest for an alternative fuel source that aligns harmoniously with sustainable development, energy preservation, efficiency, and environmental protection has gained paramount importance. This issue is particularly salient in our modern lives. The physical and chemical attributes of vegetable oil closely resemble those of mineral diesel. Consequently, vegetable oil has emerged as a viable substitute for diesel. However, it's worth noting that unrestricted utilization of vegetable oils can lead to a range of engine-related complications. To address this, the process of trans-esterification has demonstrated its efficacy as a productive method to refine vegetable oil for use as fuel. This study focuses on conducting a comprehensive review of existing literature to assess the viability of pumpkin seed oil and its biodiesel as a feasible alternative to traditional diesel.

Research Advances on Nitrogen-Doped Carbon Materials in COx Hydrogenation

The excessive consumption of fossil fuels has resulted in massive carbon emissions and serious ecological and environmental crises. Therefore, achieving the efficient utilization of waste carbon sources is considered as an important pathway to addressing the aforementioned issues in the context of carbon neutrality. Developing and designing suitable catalyst materials has become the key to converting COx into valuable platform chemicals and value-added liquid fuels (e.g., CO, CH4, CH3OH, and C2+ hydrocarbons). A moderate interaction between nitrogen-doped carbon materials and active metals is more favorable for the progress of the COx hydrogenation reaction compared to traditional metal oxide carriers. In this work, we comprehensively summarize the synthesis methods of N-doped carbon materials and the relevant research progress in the field of COx hydrogenation. In addition, a general assessment of carbon-based catalysts for COx hydrogenation reactions, concerning the support and metal properties, the activity and product selectivity, and their interactions is systematically discussed. Finally, this review discusses the roles of N-doped carbon materials, the current challenges, and future development directions.

A rational design of covalent organic framework supported single atom catalysts for hydrogen evolution reaction: A DFT study

Excessive consumption of fossil fuels and CO2 emissions exacerbate global environmental concerns. Unfortunately, fossil fuel reserves are dwindling and fossil fuel energy is unsustainable, non-renewable, and costly. Due to these concerns, there is an imperative demand for eco-friendly energy conversion electrochemical systems. Hydrogen (H2) is ubiquitously regarded as a fossil fuel substitute and a potential sustainable energy source. Water electrolysis powered by renewable resources is being considered as a sustainable approach to produce H2. To cater the need, electrocatalysts with non-precious single metal atoms supported on a covalent organic framework (TM@COF SACs) have been proposed for HER. Single atoms of Co, Ni, Cu, and Zn were introduced onto the COF substrate. The thermodynamic stability, HOMO, LUMO energies, HOMO-LUMO energy gaps, DOS spectra, and change in the Gibbs free energy of adsorbed atomic hydrogen (ΔGH∗) on the catalyst's surface are used to evaluate the catalytic performance of designed complexes for HER. Among all the considered complexes, Zn@COF demonstrated the highest potential to act as a single atom catalyst, with an Eint value of −0.11 eV. Density functional theory (DFT) findings suggest that single Zn atom doped on the surface of the covalent organic framework with ΔGH∗ value of −0.88 eV has a substantial effect on the performance of the HER. This research opens up new possibilities for the advancement and utilization of highly efficient, stable, and cost-effective single-atom catalysts for HER, thereby laying the foundation for future developments in this field.

Robust sustainable canola oil-based biodiesel supply chain network design under supply and demand uncertainty.

The excessive consumption of fossil fuels has sparked debates and caused environmental damage, leading the global community to search for a suitable alternative. To achieve sustainable development goals and prevent harmful climate scenarios, the world needs to increase its use of renewable energy. Biodiesel, a clean and eco-friendly fuel with a high flash point and more lubrication than petroleum-based fuels, and without the emission of harmful environmental gases, has emerged as one of the fossil fuel alternatives. To promote the mass-level production of biodiesel, a sustainable supply chain (SC) that does not depend on laboratory production is necessary. For this purpose, this research proposes a multi-objective mixed-integer non-linear mathematical programming (MINLP) model to design a sustainable canola oil-based biodiesel supply chain network (CO-BSCND) under supply and demand uncertainty. This mathematical model aims to minimize the total cost (TC) and total carbon emission while maximizing the total number of job opportunities simultaneously. A scenario-based robust optimization (SBRO) approach is applied to deal with uncertainty. The proposed model is implemented in a real case study in Iran, and numerical experiments and sensitivity analysis are conducted to demonstrate its applicability. The results of this research demonstrate that designing a sustainable supply chain network for the production and distribution of biodiesel fuel is achievable. Moreover, this mathematical modeling makes mass-scale production of biodiesel fuel a possibility. In addition, the SBRO method adopted in this research enables managers and researchers to explore the design conditions of the supply chain network by controlling the uncertainties that affect it. This approach allows the chain's performance to be as close as possible to the actual conditions. As a result, the SBRO method enhances the efficiency of the supply chain network and boosts productivity toward achieving desired goals.

Melting of phase change materials inside metal foams with uniform/graded porosity: Pore-scale simulation

Latent heat thermal storage system has the potential for industrial applications to reduce excessive consumption of fossil fuels. However, the commonly employed phase change materials (PCMs) have the drawback of poor heat transfer capability, causing slow charging/discharging rates for thermal storage systems. To enhance the melting rate of PCM, metal foams (MFs) with good thermal conductivity were exploited, focusing on the contribution of porosity gradients in foam structures to the melting characteristics. Based on tetradecahedron cells, geometric models of MFs with uniform porosity or porosity gradients were created, including negative gradient foam (NGF), homogeneous foam (HF), and positive gradient foam (PGF). Pore-scale numerical simulations (PNS) based on the tetradecahedron cells with porosity gradients were carried out. Results of PNS demonstrated that the complete melting time for the NGF, the HF and the PGF were 92 s, 92 s and 132 s, respectively. However, the NGF had the fastest integrated average temperature response rate (IATRR). Specifically, compared with the HF, the IATRR of NGF increased by 15.4%, while that of the PGF decreased by 36.1%. In addition, natural convection enhanced the heat transfer efficiency between the PCM and the metallic skeletons of the MF. The impact of natural convection on the phase transition process was analyzed from the microscopic pores. Under the influence of natural convection, the top PCM melted faster than the bottom PCM in the z-direction.

Enabling efficient decoupled alkaline water electrolysis using a low-cost sodium manganate solid-state redox mediator

The environmental pollution and energy crisis caused by the excessive consumption of fossil fuels have prompted a more urgent demand for the development of clean energy. As a carbon-free clean energy carrier, the sustainable production of hydrogen (H2) is a key step in the future decarbonization of the planet. Among many methods of hydrogen production, water electrolysis using renewable energy sources (e.g., solar, wind) can enable the generation of high-purity H2 in a low-carbon economy, which favors the alleviation of environmental and energy problems. In the past decades, water electrolysis has been dominated by alkaline water electrolysis, however, the oxidation and reduction reactions of water in conventional water electrolysis are closely coupled in space and time, which introduces challenges for the separation of gas products and the utilization of renewable energy. Herein, low-cost Na0.44MnO2 was chosen as solid-state redox mediator to decouple the evolution of H2 and O2 in alkaline electrolyte and obtain high-purity H2 without using any separator (membrane) or purification step. As an intermediate carrier for charge storage, the energy efficiency and decoupling efficiency can reach 98.7% and 97%, respectively, at constant current of 1.3 mA/cm2. Furthermore, we achieved flexible production of high-purity H2 by directly driving decoupled water electrolysis using intermittent renewable energy sources, confirming the potentially practical application of Na0.44MnO2.

Alternative to excessive consumption of fossil fuels in Nigeria: a case of solar energy system

In both affluent and developing countries, electricity serves as the focal point for all developmental initiatives. Alternative sources of energy must be found in order to ensure a reliable supply of clean energy for everyone as the world, and Nigeria in particular, are facing impending shortage of fossil fuels, most immediately oil, which has created a significant gap between energy demand and supply due to insufficient local production. In this article, the potential for solar energy to increase Nigeria’s energy supply is discussed. Sunlight, a renewable, non-depleting energy source, generates solar energy. The quantity of solar Energy being received by the Earth hourly is abundant to supply the required energy on annual basis. Due to the constant demand for power in our present age, solar energy is incredibly effective and pollution-free. As a result, in this regard, solar energy and its potential to improve Nigeria’s energy supply as well as its future trends are discussed. The article is aimed to cover several uses and strategies for promoting solar energy in our society: Nigeria as a case study.

Utilizing waste heat gasoline engine in the design and fabrication of a fin and tube evaporator for the Organic Rankine Cycle (ORC)

The excessive consumption of fossil fuels is causing environmental problems, which can be addressed by utilizing renewable energy sources such as hydro energy, biomass, solar heat, geothermal, and waste heat. In particular, the exhaust gas from gasoline engines presents an opportunity for energy recovery, as only 25% of the energy is utilized while the remaining 75% is wasted. A fin and tube type evaporator was designed, manufactured, and tested to utilize this exhaust gas in an Organic Rankine Cycle (ORC) system. The evaporator was designed with an outer tube diameter of 9.525 mm and a total tube length of 41.4 m, featuring 90 tubes and 135 fins with a total area of 14,325 m2. It achieved an average effectiveness of 94.33%. The results showed that the waste heat from the exhaust gas of a gasoline engine could be used as a source of energy in an ORC system with an efficiency of 2.13%. It results in 7.02 kJ/s of energy absorbed by the evaporator and a net power generated of 0.15 kJ/s. This research demonstrates the potential for utilizing waste heat from gasoline engines as an energy source to generate electricity.

Thermo-economic analysis of the performance of the combined system with evacuated tube collectors

Abstract Using combined cooling, heat and power systems can be an appropriate substitute for preventing emissions of pollutants and excessive consumption of fossil fuels. Utilizing renewable energy in these systems as a source of power generation can be an appropriate substitute for fossil-fuel-based systems. Therefore, in this paper, cogeneration cooling, heat and power systems based on gas-fired internal combustion engines with a solar-thermal system with evacuated tube collectors have been modelled and thermo-economic analysis has been done to compare fossil-fuel-based systems. The required rate of heat to supply the hot water is 50 kW. In the studied system, the internal combustion engine produces electrical energy. Then, the solar-thermal system with evacuated tube collectors and the gas-burning generator provide the thermal energy required by the studied building and the primary stimulus of the absorption chiller for cooling. In this study, two different scenarios are conducted in states considering simultaneous production systems and regardless of this environmental and thermo-economic analysis system. The results showed that the efficiency of the studied system was 60% in summer and 56% in winter.

Performance study of spiral Darrieus water rotor with V-shaped blades

Because of the excessive consumption of fossil fuels, the world has begun suffering from the depleting of those sources and wide environmental problems. Hydraulic energy, considered as unlimited and non-detrimental, has become the best refuge to supply world demand while protecting the planet. Above all vertical axis water turbine, for their low cost and independency on water direction, Darrieus turbine takes the advantage to be more suitable for some implementation. Thus, various studies have been carried out to improve its efficiency. This study emphasizes on the effect of the blade chord ratio on a spiral Darrieus water rotor performance which has not been two much explored. An experimental static and dynamic tests realized in an irrigation canal were performed with a 3D printed spiral Darrieus rotor. With the intention of the performances betterment, four spiral Darrieus rotors having a chord ratio equal to 0.25, 0.5, 0.75, and 1, respectively, were tested through numerical simulations using the ANSYS FLUENT 17.0 software. Based on the numerical study, it is provided that the rotor with chord ratio of 0.5 was the optimum. In fact, it gives maximum power coefficient of 0.188 at a tip speed ratio equal to 0.71. The obtained findings present an interesting data that could provide the hydrodynamic characteristics of the water flow for the engineers and designers to improve the performance of the spiral Darrieus rotor.

Exploring Rational Design of Single-Atom Electrocatalysts for Efficient Electrochemical Reduction of CO2 to CO

The electrochemical reduction of carbon dioxide (CO2) to value-added products is a remarkable approach for mitigating CO2 emissions caused by the excessive consumption of fossil fuels. However, achieving the electrocatalytic reduction of CO2 still faces some bottlenecks, including the large overpotential, undesirable selectivity, and slow electron transfer kinetics. Various electrocatalysts including metals, metals oxides, alloys, and single-atom catalysts have been widely researched to suppress HER performance, reduce overpotential and enhance the selectivity of CO2RR over the last few decades. Among them, single-atom catalysts (SACs) have attracted a great deal of interest because of their advantages over traditional electrocatalysts such as maximized atomic utilization, tunable coordination environments and unique electronic structures. Herein, we discuss the mechanisms involved in the electroreduction of CO2 to carbon monoxide (CO) and the fundamental concepts related to electrocatalysis. Then, we present an overview of recent advances in the design of high-performance noble and non-noble single-atom catalysts for the CO2 reduction reaction.

Analisis Potensi Pembangkit Listrik Tenaga Bayu dengan Turbin Angin Sumbu Vertikal di Kecamatan Sangkapura Kabupaten Gresik

<p><em>Gresik Regency's coastal Bawean Island is where Sangkapura District is situated. In 2020, there were 117,112 power consumers in the Sangkapura District. On the same island, there have been some regions without electricity daily. This demonstrates that there is still a need for electrical energy, which is growing along with the population. Additionally, growing global oil prices are a sign of the need for electrical energy. Fossil energy, which is non-renewable and can produce emissions, is the energy source that is most frequently used today. An energy crisis can be brought on by the excessive consumption of fossil fuels. The suggested remedy is to employ new renewable energy (EBT) as a source of electrical energy, taking into account that EBT is more environmentally friendly. Therefore, more study is required to determine the local potential of wind as a wind power plant (PLTB) using vertical axis wind turbines, taking into account the benefits and drawbacks of each type of turbine. The analysis of published works and the Meteorology, Climatology, and Geophysics Agency's online database is the research techniques used. According to the analysis, an average wind speed of 1.5 m/s and wind power of 10.47 watts were measured. Dim LED lights can be turned on with this amount of energy. Sangkapura District has a poor potential for wind power plants because this number is lower compared to numerous pertinent research and employs a home size. Therefore, we require a different strategy that can utilize low wind speeds to generate electricity.</em></p>

Bimetal Cu and Fe modified g-C3N4 sheets grown on carbon skeleton for efficient and selective photocatalytic reduction of CO2 to CO

Excessive consumption of fossil fuels leads to resource shortages and the greenhouse effect. In order to solve these problems, the conversion of CO2 to fuel using photocatalytic technology has attracted extensive attention. In this work, Cu and Fe bimetallic modified g-C3N4 sheets grown on carbonized pomelo peels (Cu/Fe-CNC) for photocatalytic reduction CO2 to CO were synthesized via chemical vapor co-deposition (CVD) method. The modification by Cu and Fe bimetallic has enhanced the transfer and separation efficiency of charge carrier and increased surface reaction sites, thereby significantly enhancing the CO yield. Compared with the bulk g-C3N4, the reduction yield of CO2 to CO is increased by 3 times and compared with C3N4 grown on carbonized pomelo peel (CNC), it increased by 2 times. And Cu/Fe-CNC can achieve 100 % reduction of CO2 to CO in the photocatalytic system. Furthermore, the Cu/Fe-CNC has excellent stability in 5 cycle experiments. This work, from a new perspective, assists in developing high active g-C3N4-based photocatalysts to achieve the efficient and selective CO2 to CO reduction.

Potential and Economic Evaluation of Biogas Resources and Location of its Power Plants with GIS in Iran

Excessive consumption of fossil fuels has led to threats to energy reserves and environmental issues as two common concerns of today’s societies. On the other hand, renewable energy sources have been growing as alternative sources to reduce severe environmental problems such as global warming, climate change, and acid rain. As a result, it is necessary to assess the potential of renewable resources and the location of power plants related to them. Among renewable energies, biomass energy and biogas have a high status and importance, accounting for a significant share of energy production. Therefore, choosing a suitable location for biogas power plants in energy production and transmission, cost reduction, and environmental aspects. Today, the use of GIS has made it possible to integrate the information needed for location effectively. Therefore, in this study, while identifying the influential factors and criteria in the location of biogas power plants and the AHP hierarchical analysis process as one of the multi-criteria MCDSS decision-making methods to the location of biogas power plants in Iran, as one of the criticalroles in the production of agricultural biomass, livestock and poultry, and waste has been addressed. The results of the economic analysis showed that the construction of biogas power plants is justified in cities where the cost of the power plant is less than 0.098 USD per cubic meter of gas produced and the average cost of biomass is less than 0.0915 USD per cubic meter of synthetic gas.

High Performance Bifunctional Electrocatalysts Designed Based on Transition-Metal Sulfides for Rechargeable Zn-Air Batteries.

Due to the energy crisis by the excessive consumption of fossil fuels, Zinc-air batteries (ZABs) with high theoretical energy density have attracted people's attention. The overall performance of ZABs is largely determined by the air cathode catalyst. Therefore, it is necessary to develop high-efficiency and low-cost bifunctional catalysts to replace noble metal catalysts to promote the development of ZABs. Among a variety of cathode catalysts, TMS has become a research hotspot in recent years because of its better electrical conductivity than metal phosphides and metal oxides. In this work, we focus on the means of improving the electrocatalytic performance of transition-metal sulfides (TMS) providing ideas for us to rationally design high-performance catalysts. Furthermore, the performance improvement law between catalyst performance and ZABs is also discussed in this work. Finally, some challenges and opportunities faced in the research of TMS electrocatalysis are briefly proposed, and strategies for improving the performance of ZABs are prospected.