Fossil Fuel-based Energy System Research Articles

Towards Achieving 100% Renewable Energy Supply for Sustainable Climate Change in Pakistan

Fossil fuel-based energy systems are mostly used for supplying energy that creates negative impacts on the environment, so in this study, the development of a 100% renewable energy system is evaluated for Pakistan for sustainable climate change. This study modeled three scenarios, namely, ongoing (ONG), energy saving policy (ESP), and green energy policy (GEP) scenarios using low emission analysis platform (LEAP) software for the study period 2022 to 2050 for Pakistan. The results revealed that a 100% renewable energy supply could be achieved through the GEP scenario. Model results show that the share of renewable sources in the total energy mix is 1117.08 TWh and non-renewable sources contribute only 18.12 TWh to meet the energy demand of 966.05 TWh until 2050. Non-renewable production leads to the generation of 8.85 million metric tons of carbon emissions, which is too low compared with the 135.47 million metric tons under the ONG scenario. The USD 1482.46 billion investment cost required for adding renewable energy capacity until 2050 is too high as compared with the USD 46.80 billion under the ONG scenario. Energy demand and production requirements are reduced by 34.18% under the ESP scenario until 2050. This approach can also be applicable to the majority of nations worldwide.

Implementation of Formic Acid as a Liquid Organic Hydrogen Carrier (LOHC): Techno-Economic Analysis and Life Cycle Assessment of Formic Acid Produced via CO2 Utilization

To meet the global climate goals agreed upon regarding the Paris Agreement, governments and institutions around the world are investigating various technologies to reduce carbon emissions and achieve a net-negative energy system. To this end, integrated solutions that incorporate carbon utilization processes, as well as promote the transition of the fossil fuel-based energy system to carbon-free systems, such as the hydrogen economy, are required. One of the possible pathways is to utilize CO2 as the base chemical for producing a liquid organic hydrogen carrier (LOHC), using CO2 as a mediating chemical for delivering H2 to the site of usage since gaseous and liquid H2 retain transportation and storage problems. Formic acid is a probable candidate considering its high volumetric H2 capacity and low toxicity. While previous studies have shown that formic acid is less competitive as an LOHC candidate compared to other chemicals, such as methanol or toluene, the results were based on out-of-date process schemes. Recently, advances have been made in the formic acid production and dehydrogenation processes, and an analysis regarding the recent process configurations could deem formic acid as a feasible option for LOHC. In this study, the potential for using formic acid as an LOHC is evaluated, with respect to the state-of-the-art formic acid production schemes, including the use of heterogeneous catalysts during thermocatalytic and electrochemical formic acid production from CO2. Assuming a hydrogen distribution system using formic acid as the LOHC, each of the production, transportation, dehydrogenation, and CO2 recycle sections are separately modeled and evaluated by means of techno-economic analysis (TEA) and life cycle assessment (LCA). Realistic scenarios for hydrogen distribution are established considering the different transportation and CO2 recovery options; then, the separate scenarios are compared to the results of a liquefied hydrogen distribution scenario. TEA results showed that, while the LOHC system incorporating the thermocatalytic CO2 hydrogenation to formic acid is more expensive than liquefied H2 distribution, the electrochemical CO2 reduction to formic acid system reduces the H2 distribution cost by 12%. Breakdown of the cost compositions revealed that reduction of steam usage for thermocatalytic processes in the future can make the LOHC system based on thermocatalytic CO2 hydrogenation to formic acid to be competitive with liquefied H2 distribution if the production cost could be reduced by 23% and 32%, according to the dehydrogenation mode selected. Using formic acid as a LOHC was shown to be less competitive compared to liquefied H2 delivery in terms of LCA, but producing formic acid via electrochemical CO2 reduction was shown to retain the lowest global warming potential among the considered options.

Tuning the Electronic Structure of Cobalt Selenide on Copper Foam by Introducing a Ni Buffer Layer for Highly Efficient Electrochemical Water Splitting.

The development of a cost-effective, remarkably competent, and durable bifunctional electrocatalyst is the foremost requirement of water splitting to generate H2 fuel as a renewable energy technology. Three-dimensional porous copper foam (Cuf) when electrochemically decorated with transition metal selenide results in a highly active electrocatalyst for adequate water electrolysis. In terms of water splitting, the role of cobalt selenide and Cuf has already proven to be remarkable. The introduction of a Ni buffer layer between Cuf and cobalt selenide (Cuf@Ni-CoSe2) acts as a valve to enhance the electron thrust from the substrate to the material surface with no compromise in the overall material conductivity, which not only increases the efficiency and activity but also improves the stability of the catalyst. The self-supported synthesized catalyst material showed an admirable activity toward the oxygen evolution reaction and hydrogen evolution reaction in alkaline media. The performance of the catalyst was found to be significantly better than that of the noble catalyst RuO2. The catalyst was very stable up to 93 h and attained a full cell voltage of only 1.52 V at a current density of 10 mA cm-2. Therefore, for large-scale hydrogen production, this as-synthesized catalyst hss the potential to replace conventional fossil fuel-based energy systems.

Social movements in energy transitions: The politics of fossil fuel energy pathways in the United Kingdom, the Netherlands and Poland

Pathways towards low-carbon energy transitions have become a priority in 21st century Europe. The commitment to lowering carbon dioxide emissions have triggered changes to current fossil fuel-based energy systems. Over the past decade, fossil fuel energy pathways have been characterized by closures of sites, continued extractions and new explorations, demonstrating processes of (dis)continuation. This paper contributes to the recent line of work that draws attention to the contentious politics in sustainability transitions and the role of social movements by drawing on case study work in which we trace social mobilizations alongside key policy and industry developments linked to onshore oil and gas and coal projects in the United Kingdom, the Netherlands and Poland over the past ten years. Drawing on the notion of scalar practices, we identify political strategies and opportunities for the discontinuation of fossil fuels, but we also examine how political spaces are impinged and closed down to support continuation processes. Our analysis demonstrates how decision-making powers and possibilities for scrutinizing and taking actions against fossil fuels are negotiated between local and central government, local communities and residents, grassroots movements, national NGOs, and fossil fuel industries. We conclude that all actors are involved in scalar practices, and non-fossil energy pathways remain challenging if the government and industry actors keep trying to displace the politics linked to fossil fuel energy.

Semiconducting Polymers for Oxygen Evolution Reaction under Light Illumination.

Sunlight-driven water splitting to produce hydrogen fuel has stimulated intensive scientific interest, as this technology has the potential to revolutionize fossil fuel-based energy systems in modern society. The oxygen evolution reaction (OER) determines the performance of overall water splitting owing to its sluggish kinetics with multielectron transfer processing. Polymeric photocatalysts have recently been developed for the OER, and substantial progress has been realized in this emerging research field. In this Review, the focus is on the photocatalytic technologies and materials of polymeric photocatalysts for the OER. Two practical systems, namely, particle suspension systems and film-based photoelectrochemical systems, form two main sections. The concept is reviewed in terms of thermodynamics and kinetics, and polymeric photocatalysts are discussed based on three key characteristics, namely, light absorption, charge separation and transfer, and surface oxidation reactions. A satisfactory OER performance by polymeric photocatalysts will eventually offer a platform to achieve overall water splitting and other advanced applications in a cost-effective, sustainable, and renewable manner using solar energy.

Sustainable hydrogen production: Technological advancements and economic analysis

Hydrogen (H2) is pivotal to phasing out fossil fuel-based energy systems. It can be produced from different sources and using different technologies. Very few studies comprehensively discuss all available state-of-the-art technologies for H2 production, the challenges facing each process, and their economic feasibility and sustainability. The current study thus addresses these gaps to effectively direct future research towards improving H2 production techniques. Many conventional methods contribute to large greenhouse gas footprints, with high production costs and low efficiency. Steam methane reforming and coal gasification dominate the supply side of H2, due to their low production costs (<$3.50/kg). Water-splitting offers one of the most environmentally benign production methods when integrated with renewable energy sources. However, it is considerably expensive and ridden with the flaw of production of harmful by-products that affect efficiency. Fossil fuel processing technologies remain one of the most efficient forms of H2 production sources, with yields exceeding 80% and reaching up to 100%, with the lowest cost despite their high reliance on expensive catalysts. Whereas solar-driven power systems cost slightly less than $10 kg−1, coal gasification and steam reforming cost below $3.05 kg−1. Future research thus needs to be directed towards cost reduction of renewable energy-based H2 production systems, as well as in their decarbonization and designing more robust H2 storage systems that are compatible with long-distance distribution networks with adequate fuelling stations.

Numerical Analysis of a Residential Energy System That Integrates Hybrid Solar Modules (PVT) with a Heat Pump

Photovoltaic-thermal (PVT) collectors are hybrid solar collectors that convert solar and ambient energy into thermal and electrical energy. Integrated PVT-HP, in which PVT collectors are combined with a heat pump, offers an efficient and renewable option to replace conventional fossil fuel-based energy systems in residential buildings. Currently, system concepts in which the selection, design and control of the components are aligned towards the system performance are lacking. The development of a system model enables the comparison of a variety of system parameters and system designs, informed decision making based on the energetic performance and the market diffusion of PVT-HP systems. This contribution presents a simulation model of a PVT-HP system. By means of numerical simulations, with simulation program TRNSYS, the energetic performance of a PVT-HP system and the system components are investigated. It is shown that the PVT-HP can cover the annual energy demand of a residential building. The corresponding Seasonal Performance Factor (SPF) is equal to 3.6. Furthermore, the effect of varying weather conditions, occupancy and building orientations on the performance of the reference system is analyzed. The SPF for the investigated scenarios varies between 3.0 and 3.9. Lastly, two system parameters, the PVT collector area, and the PVT collector type are varied as an initial step in the optimization of the system performance. To sum up, the presented PVT-HP model is suitable for dynamic system simulation and the exploration of the system concepts. The simulation study shows that a PVT-HP system can cover the annual energy demand of a residential building. Lastly, parametric variations showcase the optimization potential of PVT-HP systems.

Demand-side management and renewable energy business models for energy transition A systematic review

Recent developments in technology have been considered a critical factor in fighting climate change and accelerating energy transition. These developments are changing the current centralized and fossil fuel-based energy system into a new system with integrated renewable energy resources. The developments also facilitate the emergence of new business models and allow entrepreneurs to propose new products and services. This paper aims to identify the existent energy business models based on a systematic literature review, focusing on two main areas: renewable energy and demand-side management. With that purpose, a framework is described including specific characteristics for energy business models. Based on this framework, 22 different energy business models are presented clustered in eight patterns. The study draws on an exhaustive picture of the emerging business models and provides insights for researchers and for early-stage companies to innovate through business model transformation.

Study on the capacity-operation collaborative optimization for multi-source complementary cogeneration system

Combining renewable energy with fossil fuel-based energy systems is a promising way to develop renewable energy power generation and decrease CO2 emissions with lower capital investment. In this paper, a multi-source complementary cogeneration (MCC) system is investigated in which the wind farm and solar aided combined heat and power (SA-CHP) system are integrated at the power grid level. A bi-level capacity-operation collaborative optimization model for this MCC system has been established to simultaneously optimize main components capacities and system annual load dispatch. In the proposed model, the upper level is a multi-objective optimization searching for the optimal trade-off between economy and CO2 emissions. At the same time, the lower level aims to obtain the optimal load dispatch of the MCC system for the whole year to maximize the annual operating income. The linear model of the SA-CHP system is built to simplify the lower-level problem–solution process. The bi-level optimization model is handled with a nested approach that combines non-dominated Sorting Genetic algorithm-II and linear programming. The proposed bi-level model is applied in a study case to simultaneously optimize thermal energy storage capacity, solar field size, wind farm capacity, as well as annual power and heat load dispatch of an MCC system located in Zhangbei, China. Besides, the influences of capacity parameters on the performances of the MCC system are analyzed.

Impedance modeling for polymer electrolyte membrane fuel cells by combining the transient two-phase fuel cell and equivalent electric circuit models

Proton exchange membrane fuel cell (PEMFC) are actively replacing fossil fuel-based energy systems in commercial applications. Evaluation of cell performance and degradation is critical and usually performed by analyzing the polarization curve and/or Nyquist plot. The polarization test provides an insight into the entire cell, whereas electrochemical impedance spectroscopy (EIS) is used to obtain the Nyquist plot that facilitates the assessment of individual voltage losses occurring in the inner components of a PEMFC. This paper highlights the degradation assessment of PEMFCs using a coupled one-dimensional (1-D) two-phase PEMFC model and Randles-TLM equivalent circuit model. The 1-D model includes a micro-scale catalyst layer (CL) model to more accurately assess electrochemical catalyst activity and mass transport inside the agglomerated porous structure of CL. This model is utilized to estimate key input parameters for various PEMFC operating conditions and degradation scenarios, which are then applied to the equivalent circuit model. The coupled model simulations successfully reproduce both experimental polarization curves and Nyquist plots for various PEMFC conditions. This study enhances the understanding of underlying physical phenomena occurring during long-term PEMFC operations.

Analysis and proposal of energy planning and renewable energy plans in South America: Case study of Ecuador

This research evaluates the South American Electric Energy System and its features related to the inclusion of renewable energies into the transition processes to leave fossil fuel-based energy systems behind. Analysis of the Ecuadorian case is a novel approach because in the first instance its matrix was based on the use of fossil fuels, with dire consequences of pollution, especially in the Amazon. Interest is growing in terms of economic, legal and social renewal, leaving behind the rapidly depleting oil systems which have been a polluting source. This research presents a novel analysis of the state of the Ecuadorian electricity system and after a flexible analysis in Energyplan, proposes the feasible renewable energy sources and their shares to guarantee the new demand in 2050 and an Ecuadorian 100% renewable electricity generation system, having a positive impact on the monetary, increasing production levels and improving the quality of life of its citizens. Installed power by 2050 is expected to be 20 GW and will require an annual production of 72.24 TWh. Hydro (6.02 GW), solar PV (5.7 GW) and wind (5.61 GW) will have the most impact on the Ecuadorian energy matrix. The average production cost of 1 MWh will be approximately 18 US cents.

Roles of Metal-Free Materials in Photoelectrodes for Water Splitting

ConspectusPhotoelectrochemical (PEC) water splitting is an appealing approach to the hydrogen evolution reaction since it converts sunlight in the form of hydrogen fuel, which has the potential to revolutionize the fossil fuel-based energy systems of the modern society. In the last half century, progress has been made with respect to the material, synthesis, and system. Recent developments of multilayered photoelectrodes have made a breakthrough to improve the sunlight conversion efficiency and strengthen the physiochemical stability. The exploration of new materials for the functional layers of photoelectrodes offers a new opportunity for practical application. Among the emerging materials, metal-free species have shown superior properties, such as high stability, sustainability, and renewability. With respect to inorganic materials, their physiochemical properties can be readily regulated, including thermodynamics and kinetics, and thus increasing attention has been devoted.In this Account, the functional components of a photoelectrodes are specified, namely conductive layers for charge separation and transfer, photocatalytic layers for light absorption, passivation layers for protection of the electrode, and cocatalysts for the acceleration of the surface reaction. We have focused metal-free materials for the functional layers, including the (1) carbon cloth and carbon quantum dots (CQDs) for the conductive layer, 2) polymeric carbon nitrides (PCNs), carbon doped boron nitride, and covalent organic frameworks for photocatalytic layers, and (3) CQDs and black phosphorene for cocatalysts. We aim to identify the relationship between the function of the metal-free materials and the performance of the water splitting reaction. With respect to the outlook, discussions have been presented for the further development of metal-free materials to improve the performance of each functional layer. Despite the fact that the use of metal-free materials for PEC water splitting is still in its infancy, this Account not only provides new thoughts and opportunities to pursue an improved performance for the water-splitting reaction but also stimulates advanced applications by using metal-free PEC systems.

Regional Environmental Impact Assessment of Renewable Energy System in California

Fossil-fuel based energy systems pose a great threat to the climate and ecosystem. Renewable energy is considered the key to achieve carbon neutrality and Sustainable Development Goals. California is a forerunner in promoting renewable energy and sustainable development. In this study, we conduct a life cycle assessment (LCA) on the renewable energy system of California between 2001 and 2019, assessing the abiotic resource depletion potential (ADP), global warming potential (GWP), ozone depletion potential (ODP), acidification potential (AP), photochemical oxidant formation potential (POFP), and eutrophication potential (EP), respectively . We show that solar energy and biomass and waste-to-energy were the main contributors to the overall life cycle impacts of California renewable energy system during 2001-2019, which accounted for 9.0%±1.2% and 90.7%±1.2%, respectively. Impacts on AP, POFP, EP and GWP from these two renewable sources are particularly evident. Geographically, Kern currently holds the most renewable energy generation (15.3 TWh in 2019) in the state, but Los Angeles has the highest environmental impact (1.2E-0.5 in 2019) due to a larger portion of waste-to-energy system. Renewable energy are essential for decarbonization, but the environmental impacts of certain sources, such as solar energy and waste-to-energy, demand further reduction through technology advancement and improved resource management.

수소연료전지차의 연료 공급을 위한 수소 공급망 구축 최적화

The hydrogen economy refers to an economic structure that uses hydrogen as its primary energy source by replacing traditional fossil fuel-based energy systems. In particular, increasing the adoption of hydrogen fuel cell vehicles(HFCVs) is one of the key factors driving the hydrogen economy, and active investment in hydrogen charging infrastructure is essential for large-scale introduction of HFCVs. In this paper, we deal with the design of the hydrogen supply network in the transportation sector. In the design of the hydrogen supply network, we determine the locations and production volumes of the hydrogen production facilities, the locations and storage capacities of the hydrogen storage facilities, and the transport volumes and means of transport of hydrogen from the production sites to the demand sites. To do this, we propose the mixed integer programming model to minimizes the cost of hydrogen production and transportation. Our case study addresses a nationwide hydrogen supply network for refuelling HFCVs planned to be introduced by 2030 in Korea. Computational experiments conducted for a variety of scenarios for the design parameters of the hydrogen supply network show that our model can be effectively used for the design of hydrogen supply network in the transportation sector.

Strategies for Reduction of Harmful Emissions from Diesel Engines

Reduction of harmful exhaust emissions from combustion of fossil fuels from automotive sectors is of prime importance and extensively researched by various strategies. Engine emissions control techniques can be bifurcated in categories of active control techniques and passive control techniques. In the active control techniques, the emissions are controlled in the combustion chamber itself while in the passive control techniques the emissions are controlled after completion of combustion. There are different strategies such as alternative fuels, fuel additives, nanofluids, water-in-diesel etc. commonly used to reduce harmful emissions and improve performance of fossil fuel-based energy systems. The alternative fuels such as alcohol and biodiesel are gaining importance. Biodiesel has certain limitations but blending with alcohol enables the maximum usage of biodiesel in the fuel blends. In this paper active control strategies are highlighted and discussed.

Optimal Planning of Integrated Nuclear-Renewable Energy System for Marine Ships Using Artificial Intelligence Algorithm

Ocean-going ships are one of the primary sources of Greenhouse Gas (GHG) emissions. Several actions are being taken to reduce the GHG emissions from maritime vessels, and integration of Renewable Energy Sources (RESs) is one of them. Ocean-going marine ships need a large amount of reliable energy to support the propulsive load. Intermittency is one of the drawbacks of RESs, and penetration of RESs in maritime vessels is limited by the cargo carrying capacity and usable area of that ship. Other types of reliable energy sources need to be incorporated in ships to overcome these shortcomings of RESs. Some researchers proposed to integrate fossil fuel-based generators like diesel generators and renewable energy in marine vessels to reduce GHG emissions. As the penetration of RESs in marine ships is limited, fossil fuel-based generators provide most of the energy. Therefore, renewable and fossil fuel-based hybrid energy systems in maritime vessels can not reduce GHG emissions to the desired level. Fossil fuel-based generators need to be replaced by emissions-free energy sources to make marine ships free from emissions. Nuclear energy is emissions-free energy, and small-scale nuclear reactors like Microreactors (MRs) are competent to replace fossil fuel-based generators. In this paper, the technical, environmental, and economic competitiveness of Nuclear-Renewable Hybrid Energy Systems (N-R HES) in marine ships are assessed. The lifecycle cost of MR, reliability of the proposed system, and limitations of integrating renewable energy in maritime vessels are considered in this study. The proposed N-R HES is compared with three different energy systems, namely ‘Standalone Fossil Fuel-based Energy Systems’, ‘Renewable and Fossil Fuel-based Hybrid Energy Systems’, and ‘Standalone Nuclear Energy System’. The cost modeling of each energy system is carried out in MATLAB simulator. Each energy system is optimized by using the Differential Evolution Algorithm (DEA), an artificial intelligence algorithm, to find out the optimal configuration of the system components in terms of Net Present Cost (NPC). The results determine that N-R HES has the lowest NPC compared to the other three energy systems. The performance of the DE algorithm is compared with another widely accepted artificial intelligence optimization technique called ‘Particle Swarm Optimization (PSO)’ to validate the findings of the DE algorithm. The impact of control parameters in the DE algorithm is assessed by employing the Adaptive Differential Evolution (ADE) algorithm. A sensitivity analysis is carried out to assess the impact of different system parameters on this study’s findings.

Analysis of nuclear-renewable hybrid energy system for marine ships

While several actions are being taken to reduce Greenhouse Gas (GHG) emissions from land-based transportation, marine transportations are often unnoticed. Ocean-going marine ships are accounted for a large amount of global GHG emissions. Renewable Energy Sources (RESs) are free from GHG emissions and playing an important role in sustainable development by lessening GHG emissions. Integration of RESs in ocean-going marine ships could be an option to make marine transportation free from emissions. Ocean-going marine ships require a large amount of reliable energy to support the propulsive load demand. RESs are intermittent, and a large amount of energy cannot be stored economically by the available energy storage techniques. Additionally, the penetration of RESs in a marine ship is limited by the available area and total weight carrying capacity of that marine ship. Because of these limitations of RESs in marine ships, there is a requirement of integrating other types of energy sources with RESs to support the baseload energy demand and to avoid the variableness of RESs. Conventional fossil fuel-based generators, like diesel generators, can be incorporated with RESs to overcome these shortcomings of RESs. However, as the penetration of RESs is limited to marine ships, most of the energy is supplied by fossil fuel-based generators. Therefore, the integration of RESs with fossil fuel-based generators merely reduces GHG emissions and is not a feasible option to make marine ships free from emissions. Fossil fuel-based generators need to be replaced by emissions-free and reliable energy sources to make the marine ships free from emissions. Small scale nuclear reactors, such as Small Modular Reactors (SMRs) and Microreactors (MRs), are free from GHG emissions and are competitive candidates to replace fossil fuel-based generators. In this paper, four different energy systems have been analyzed for marine ships namely ‘Stand-alone Fossil Fuel-based Energy System’, ‘Stand-alone Nuclear Energy System’, ‘Renewable and Fossil Fuel-based Hybrid Energy System’ and ‘Nuclear-Renewable Hybrid Energy System (N-R HES)’ in terms of certain Key Performance Indicators (KPIs). The KPIs include the Cost of Energy (COE), Net Present Cost (NPC), and GHG emissions. The results show that the N-R HES could be the best energy system for the marine industry to reduce GHG emissions and improve economic performance. A sensitivity analysis is also carried out by changing certain parameters to reinforce the findings of this study.

Engineering risk assessment of photovoltaic-thermal-fuel cell system using classical failure modes, effects and criticality analyses

As renewable energy technologies (RETs) replace fossil fuel-based energy systems, the need to address the risks and reliability of emerging RETs suitable for integration into energy infrastructures becomes urgent. The intermittency of renewable energy sources and individual characteristics of the components of RETs are potential causes of power curtailment, system failure, techno-economic costs, and the inertia to transit to renewable energy utilisation. Here, we applied the classical failure modes, effects, and criticality analyses to assess the effects of failure modes of the components of an integrated photovoltaic-thermal-fuel cell system. Risk items were identified with their possible failure modes, mechanisms, and effects to generate risk priority numbers and Criticality values. Results showed that the risk of no solar radiation, hydrogen leakage, failure of photovoltaic module, leakage of oxygen had risk priority number of 450, 270, 240, 240 whilst their corresponding Criticality values were 90, 54, 80, 48, respectively. Generating power with both battery and fuel cell may improve the overall reliability of the system. Eventually, some recommendations were made to improve the system for off-grid and grid-connected applications to supply electrical energy and hot water. Therefore, addressing the identified risk items could significantly improve the reliability and operational efficiency the system. • FMEA and FMECA of an IPVTFC have been implemented. • Risk of intermittency of solar radiation can be mitigated with energy storage systems. • Combining batteries and fuel cells can improve the reliability of IPVTFC systems. • Recommendations on how identified risk items can be managed are presented.

ASEAN’s Energy Transition towards Cleaner Energy System: Energy Modelling Scenarios and Policy Implications

The Association of Southeast Asian Nations (ASEAN) faces tremendous challenges regarding the future energy landscape and how the energy transition will embrace a new architecture—including sound policies and technologies to ensure energy access together with affordability, energy security, and energy sustainability. Given the high share of fossil fuels in ASEAN’s current energy mix (oil, coal, and natural gas comprise almost 80%), the clean use of fossil fuels through the deployment of clean technologies is indispensable for decarbonizing ASEAN’s emissions. The future energy landscape of ASEAN will rely on today’s actions, policies, and investments to change the fossil fuel-based energy system towards a cleaner energy system, but any decisions and energy policy measures to be rolled out during the energy transition need to be weighed against potentially higher energy costs, affordability issues, and energy security risks. This paper employs energy modelling scenarios to seek plausible policy options for ASEAN to achieve more emissions reductions as well as energy savings, and to assess the extent to which the composition of the energy mix will be changed under various energy policy scenarios. The results imply policy recommendations for accelerating the share of renewables, adopting clean technologies and the clean use of fossil fuels, and investing in climate-resilient energy quality infrastructure.

Biogas production from wastewater treatment: Evaluating anaerobic and biomagnetic systems

Biogas, a green and sustainable form of energy produced during the degradation of organic waste anaerobically comes with ecological and economic paybacks when compared to a comprehensive fossil fuel-based energy system. However, the biodiversity of microorganisms and chemical loads for enzymatic and bioconversion reactions impedes the anaerobic digester’s (AD) practicality for commercialization. Hence, this study examined the application of titanium dioxide magnetite (Fe-TiO2) (F) via a synthetic route in AD + F and a biomagnetic system (BMs) as a collective pathway to maximize methane potentials, wastewater treatment, and improve biogas production. The AD + F and BM systems were operated at a working volume of 0.8 L (inoculum to wastewater ratio of 0.6), the mesophilic temperature of 35 °C for an incubation period of 30 days. The results showed in-situ Fe-TiO2 facilitated the bio-electrolysis and bio-methanation reactions in the AD process which improved its performance as compared to the control (AD only). Above 75% of chemical oxygen demand (1600 ± 16.2 mg/L), Total Kjeldahl Nitrogen (76 ± 6.4 mg/L), total solids (135 ± 12 mg VS/L), volatile solids (94 ± 6.8 mg VS/L), and other inorganic contaminants (28 elementals) contained in the wastewater were removed by the BMs at a pH of 6.5 followed by the AD + F (65–75%) and the AD only (50–65%). On the 20th day, the control system (AD only) had a maximum daily biogas yield of 50 mL/COD.d, whereas the AD + F gave 90 mL/d and BMs 120 mL/d. Compared to the control with a methane yield of 66%, the addition of the Fe-TiO2 to AD + F and BMs increased the methane yield to 100%. Synergistically, the catalytic and biomagnetic activity of Fe-TiO2 in the BMs heightened the adsorption and reaction pathway of the contaminant’s transformations and degradation. Amidst two kinetic models investigated, the cumulative biogas yield followed the Gompertz kinetic model. In conclusion, combining the magnetic effect with green magnetic catalyst (Fe-TiO2) in AD and adsorption–based wastewater settings have viable prospects towards environmental purification.