Carbon-neutral Source Research Articles

Recycling of Protonic Solid Oxide Cells with Physio-Electrochemical Networks (RSPEN)

The global shift towards renewable and sustainable energy, with a focus on reducing reliance on fossil fuels and curbing carbon emissions, has led to the rise of hydrogen production via water electrolysis, powered by carbon-neutral sources. As demand for hydrogen grows, so does the need for efficient electrolyzers, such as solid oxide electrochemical cells (SOCs), with projections indicating a significant increase in global hydrogen electrolyzer capacity by 2050. However, the scaling up of SOC production presents challenges, including the need for large-scale raw material production, reliance on commercial products, and environmental impacts of waste. Particularly, over a ton of valuable waste ceramic materials are used per megawatt of SOC stack, necessitating effective recycling methods. Herein we propose a novel, scalable closed-loop recycling method for both proton conducting and oxygen ion conducting SOCs, involving active comminution, followed by electrochemical leaching and cell regeneration using recycled raw materials/precursors. The technology could achieve above 90% electrolyte material recovery, 95% CRM recovery from cathode and = 95% recovery in full cell performance. This technology not only addresses a significant gap in current recycling practices but also sets a precedent for future advancements in the field, potentially influencing broader practices in the recycling of multi-functional ceramic systems.

Unveiling Direct Electrochemical Oxidation of Methane at the Ceria/Gas Interface.

Solid oxide fuel cells (SOFCs) stand out in sustainable energy systems for their unique ability to efficiently utilize hydrocarbon fuels, particularly those from carbon-neutral sources. CeO2-δ (ceria) based oxides embedded in SOFCs are recognized for their critical role in managing hydrocarbon activation and carbon coking. However, even for the simplest hydrocarbon molecule, CH4, the mechanism of electrochemical oxidation at the ceria/gas interface is not well understood and the capability of ceria to electrochemically oxidize methane remains a topic of debate. This lack of clarity stems from the intricate design of standard metal/oxide composite electrodes and the complex nature of electrode reactions involving multiple chemical and electrochemical steps. This study presents a Sm-doped ceria thin-film model cell that selectively monitors CH4 direct-electro-oxidation on the ceria surface. Using impedance spectroscopy, operando X-ray photoelectron spectroscopy, and density functional theory, it is unveiled that ceria surfaces facilitate C─H bond cleavage and that H2O formation is key in determining the overall reaction rate at the electrode. These insights effectively address the longstanding debate regarding the direct utilization of CH4 in SOFCs. Moreover, these findings pave the way for an optimized electrode design strategy, essential for developing high-performance, environmentally sustainable fuel cells.

Hydrogen and Hydrocarbon Fuels from Abundant Resources and Solar Energy: Current Activities and Perspectives in DLR’s Institute of Future Fuels

Abstract Chemical energy carriers, centralized around Hydrogen products, will play an essential role in the energy system of the future. The advantages of comparable power density and reliability to fossil fuels, as well as their versatile applications, make them an important component of the energy transition. DLR is conducting research on technologies that ensure the efficient production of chemical energy carriers. De-carbonizing the energy system and of industry needs not only electricity from carbon-neutral sources but also green fuels. DLR’s Institute of Future Fuels steps in at that point by developing and investigating production methods for hydrogen and synthetic hydrocarbon fuels. Those are mostly based on the utilisation of concentrated sunlight but in additionally also on other renewable resources. The development goes all along the way of identifying and qualifying suitable functional materials, over integrating them in specific components allowing to introduce renewable energy into the process, towards the demonstration of a representative overall process along the chain from raw materials to the targeted fuel. Hydrogen plays a key role in this context, either as the fuels itself or as a core building block of synthetic hydrocarbon fuels and chemicals. The institute has a specific focus on thermochemical processes, in particular for water and CO2 splitting, but also on air separation, thermochemical heat storage and upgrading of biomass and other hydrocarbons.

The emerging international trade in hydrogen: Environmental policies, innovation, and trade dynamics

Hydrogen produced from renewable energy and other carbon-neutral sources has the potential of becoming an important medium for storing and transporting energy, partially taking on the role that fossil fuels play to date. We develop a novel theoretical and empirical model of sequential trade based on long-term contracts with one or more fixed-capacity projects entering each period in a modified Nash-Cournot competition. We simulate the emerging international trade in hydrogen using calibrated demand, supply, transportation, and policy data, exploring a set of scenarios to determine which factors have significant influence—in particular environmental, innovation, and trade policies. Our findings suggest that hydrogen trade exhibits significant price dispersion and two-way trade as vintages of contracts overlap in a market defined by endogenous innovation and policy interventions. Trade costs and the mode of transportation (pipelines or ammonia conversion, possibly others) play a pivotal role and influence the relative share of hydrogen production types (green, blue, or turquoise). Trade policies emerge as a more essential determinant of hydrogen trade than carbon and innovation policies.

Ultrasonication-induced metabolic pathway shifts and reduced electron carrier washout with biomass enhanced hydrogen yield in a continuous stirred tank reactor

Biohydrogen is pivotal for hydrogen economy, providing a renewable, carbon–neutral source of hydrogen from organic waste and biomass. It addresses environmental concerns and supports circular economy principles. However, challenges like managing metabolic pathways and dissolved hydrogen hinder attainment of higher hydrogen yields. This study explored the impact of organic loading rates (OLR) and ultrasonication on glucose fermentation by Clostridium pasteurianum for biohydrogen production.Results showed ultrasonication, particularly at 10 g/L.d OLR, increased hydrogen yield from 1.04 to 1.28 mol-H₂/mol-glucose. Higher OLR boosted biogas production, and at 10 g/L.d OLR, ultrasonication improved hydrogen purity from 46% to 53%, enhancing yield by 13%. C. pasteurianum shifted metabolic pathways under higher OLR, increasing lactate production to address redox imbalance. However, ultrasonication negatively affected lactate and acetate reutilisation, redirecting carbon flux from lactate to butyrate, increasing hydrogen yield.Combining ultrasonication and increased OLR enhanced glycolysis carbon flux by 14.5% and reduced biomass carbon flux by 10.5%. Hydrogen yield, influenced by glycolysis carbon flux, reached 82% under ultrasonication and increased OLR. Ultrasonication mitigated inhibitory effects on electron carrier molecule re-oxidation, emphasising the need to balance biomass, dissolved hydrogen concentration, and OLR for optimal hydrogen recovery.Despite decreased acetate/butyrate ratio and unchanged theoretical hydrogen production with ultrasonication, hydrogen yield increased. This likely resulted from reduced electron carrier molecule wastage with biomass, influenced by higher biomass concentration and ultrasonication. The study underscored preventing electron carrier molecule washout for higher hydrogen production and recommends using batch reactors over continuous stirred tank reactors in dark fermentation operations.

Strategic pathways to sustainable energy: Carbon emission pinch analysis for Bangladesh's electricity sector

Balancing burgeoning energy demands in the electricity sector while curbing carbon emissions poses a formidable challenge for emerging economies like Bangladesh, which is heavily reliant on fossil fuels. Despite the country's power system master plan (PSMP) until 2041 and submitted intended nationally determined contributions (INDC) to tackle mounting energy needs and associated emissions, the PSMP lacks specific emission reduction strategies. Thus, this study employs carbon emission pinch analysis to facilitate Bangladesh's long-term energy planning, highlighting emission reduction hurdles. This research aims to set emission limits, delineate fossil fuel and carbon-neutral source (i.e., zero emission during operation) compositions, ascertain carbon-neutral source ranges for targeted emissions, and propose viable carbon-neutral sources to meet escalating energy demands. Three scenarios are extensively explored: fulfilling INDC mandates, a 10% increase in renewable energy, and maintaining 2035 emission levels in 2040. The analysis unveils emission limits of 55 758.83 and 84 778.61 × 109 grams of CO2 equivalent for 2025 and 2030, respectively. Projections indicate a foreseen 10% surge in renewable energy by 2035, elevating its share to 18.16%. Carbon-neutral energy sources, encompassing solar, wind, hydroelectricity, biomass, and nuclear, are estimated to cover 56.06% of energy demand by 2040, driving a 33.30% emissions reduction.

A novel two-stage immobilized bioreactor for biohydrogen production using a partial microalgal-bacterial (Chlorella vulgaris and wastewater activated sludge) co-culture

Biohydrogen (bioH2) has the potential to be a sustainable and carbon–neutral source of bioenergy, as it does not produce any greenhouse gas emissions. Various strategies and techniques such as algal-bacterial co-culturing and bioreactor configurations have been applied to improve bioH2 yield and regulate process inhibitors (low pH and high organic acids yield). Therefore, in current study, the co-culturing of Chlorella vulgaris (C. vulgaris) and domestic wastewater activated sludge (WWAS) was exploited in an innovative way by immobilization in two separate bioreactors. The C. vulgaris and WWAS were immobilized in sodium alginate and Z-medium was utilized as a source of nutrient supplemented with 10 g/L of glucose as external carbon source. The maximum bioH2 production of 9.8 and 222.7 mL/L was obtained in microalgal and bacterial chambers, respectively. Acetic acid accumulation was reduced to below 150 mg/L which is 90 % less compared to previous studies and subsequently the pH raised ranging from 7.0 to 10.0 during six days of incubation period. The results suggest that immobilized microalgae and WWAS in partial co-culture tend to reduce process inhibitors by increasing pH via microalgal photosynthesis and bioH2 production via sugar fermentation, respectively. The strategy to split microalgal-bacterial co-culture into separate chambers provides the ability to work microalgae and bacteria separately but in a symbiotic manner.

Visible Light Photocatalysis: Green Hydrogen Production

The next few decades will experience the convergence of diverse materials and scientific disciplines resulting in innovative products and processes for the benefit of mankind. If the proliferation of today’s technologies and the urgent need to address global climate change issues is any indication of the speed and power of changes in economies to be expected, a dramatic shift to sustainable technologies has to occur to provide cost-effective, low carbon footprint solutions. In this talk we will introduce about possible strategies based on fundamentals of physics and materials engineering that can potentially contribute to our efforts to preserve the planet’s environment at an acceptable level. Exploiting solar energy, as visible radiation constitutes a major share (~ 46%) of the solar spectrum, strategies for carbon reduction technologies can be devised. We have been working on the synergistic development of visible light active photocatalysts suitable for activating reactions by engineering nanomaterials and interfaces. Hydrogen production (H2) by Photocatalytic reactions is a promising process for green H2 generation as a fuel or an alternate energy source. Organic compounds like alcohols, polyols, sugars, as well as organic acids and lignocellulosic compounds can serve as sacrificial agents (electron donors) to reduce e−–h+ recombination leading to a more efficient process. Cellulose, the most abundant material on the earth that is a part of some of the waste generated by humans is a natural and carbon-neutral source as a sacrificial agent during photo-induced splitting of water for green H2 production and can be an attractive for building a sustainable system for photocatalytic H2 production. Some of these areas utilising visible light photocatalysis for oxidation of organic pollutant, microbe removal, anti-biofouling coatings and microplastic degradation will be briefly discussed.

Comparative energy performance analysis of micro gas turbine and internal combustion engine in a cogeneration plant based on biomass gasification

With a view to replacing fossil fuels, biomass electricity generation worldwide has grown from 509 TWh in 2015 to 685 TWh in 2021 and an upward trend is expected for the next years. It is about dispatchable, low-emission power to complement generation from variable renewables. Although modern bioenergy is considered a stable and carbon-neutral source, there is a need to boost the efficiency of the Biomass-to-Energy (BtE) conversion technologies. Accordingly, in this modeling study, attention was drawn to biomass gasification for heat and power, with a special focus on the prime mover characterization for distributed generation. An internal combustion engine (ICE) and a micro gas turbine (mGT), having the same nominal capacity of about 240 kWel when fueled by natural gas (NG), were inserted into a two-way biomass gasification chain and hence fed by clean syngas deriving from a downdraft gasifier. Simulations of the main components of the thermal power plant (gasifier, syngas cleanup, power island) were validated against data available in the published literature and in technical sheets, for specific operating conditions. The next step was to evaluate the overall performance of the entire BtE chain in terms of electrical, thermal, and total efficiency, both at full and part load, in order to highlight the pros and cons of each generator, in a twofold perspective. The last goal was to simulate a load following strategy, for two typical cold and hot days. The results of the thermodynamic analysis indicate that ICE is better performing than mGT, in the simulated context where the power demand from the grid ranges from 80 kWel to 190 kWel, with an ambient temperature between 2 and 35 °C. ICE provides the best performance in CHP mode, with a total efficiency of 62–69%.

Nanomaterials mediated valorization of agriculture waste residue for biohydrogen production

Hydrogen is consider as clean fuel with potential source of unlimited clean power. The global market for the hydrogen generation is expected to be $317.39 billion by 2030. The key factors responsible for hydrogen generation market includes high demand of conventional fuel in steel, cement and power generation industries and government initiatives for green and sustainable environment. It is of the utmost note that the major production of hydrogen is based on conversion from fossil fuels such as coal, petroleum etc. Among green hydrogen production method transformation of biomass to biohydrogen via anaerobic fermentation is considered as carbon neutral source of energy. However, the yield of hydrogen production is low and depends upon various factors such waste composition, bioreactor type, and microorganisms used its production, but production is limited due to shortage of raw materials. Since, the biomass such as agriculture waste residues are largely available as corn stover, sugar beet juice, beverage waste; water, wheat straw, rice straw, wood chips, sawdust, shrubs, and branches etc. The major hurdle in dark fermentation is lower biohydrogen yield due to inefficient conversion of carbohydrates into biohydrogen. Nanomaterials can help in valorization of agriculture residue for efficient biohydrogen production. Nano-technological application like increasing surface area, enzyme stability and saccharification efficiency of enzyme can contribute in biohydrogen production. Nanoparticles may result in a shift in the microbial community and the metabolic pathway for hydrogen production. This review explore the impending application of nanomaterial for valorization of agriculture biomass, biochemical pathways, and possible application of nanomaterial as individual or in composite to improve biohydrogen production.

The effect of the future of nuclear energy on the decarbonization pathways and continuous supply of electricity in the European Union

Nuclear power plants play an extremely important role in the European Union's electricity supply. Nuclear power is the largest carbon neutral source of electricity and the most important baseload electricity producer in Europe. The existing 167 units represent a capacity of 148 000 MW, which in 2022 accounted for 22 % of the electricity generated in the EU-27. In most countries, there are plans to keep nuclear power plants in operation and then extend their lifetime. In most of the European countries that already have nuclear power the construction of new units is planned, as well as in Poland, which is a nuclear newcomer.Meanwhile, Germany has phased out nuclear power in 2023 and this move is also being considered in other countries. In this article, we address the question of what the impact would be in the EU member states if nuclear power plants were to be phased out and replaced by solar, wind and gas-fired capacities.To do this, energy strategies for EU countries with nuclear power were analysed, hourly resolution electricity supply models were constructed for 15 countries and the main electricity supply characteristics for year 2030 and 2040 were assessed for three different power plant portfolios in each country under study. For the different scenarios, specific results are presented on the primary energy mix, CO2 emissions, natural gas demand and high time resolution characteristics of electricity supply.

Numerical investigation on the use of Dimethyl Ether (DME) as an alternative fuel for compression-ignition engines

Dimethyl Ether (DME) is an oxygenated fuel that could favour the transition of the heavy-duty transportation sector to carbon neutrality thanks to its similarities in terms of thermophysical properties with diesel fuel, which will facilitate the retrofitting of existing architectures, and the possibility to achieve good trade-offs between NOx emissions, soot formation and overall combustion efficiency. The possibility of producing it from a multitude of carbon–neutral sources and the low hydrogen-to-carbon ratio would allow for an overall lower CO2 output, making an attractive option in limiting the global warming impact of the heavy-duty transportation sector. In the present work, a numerical analysis of the combustion process of DME is carried out. First, the numerical setup is validated against experimental data available for a constant volume vessel with an initial density of 14.8 kg/m3, discussing the capabilities of a chemistry-based combustion model using tabulated kinetics of homogeneous reactors: the Tabulated Well Mixed (TWM) model. Ignition delay times (IDT) are compared for a wide range of temperatures, from 750 K to 1100 K, and oxygen concentrations, from 15% to 21%. The same setup is then applied in the simulation of a heavy-duty internal combustion engine (ICE). A first validation was done to assess the performance of the numerical methodology in a traditional Mixing Controlled Compression Ignition (MCCI) scenario. Then, two other points were simulated: an MCCI condition with 35% of EGR and a Late-Premixed Charge Compression Ignition (L-PCCI) one, with 35% of EGR and an SOIe of 4 CAD aTDC. Local temperature distributions were compared, analyzing the effect of these technologies in NOx emission mitigation and their impact on gross indicated efficiency (ηg), showing the advantages that using DME can have on a real-world application.

Mechanistic Studies of the Deoxydehydration of Polyols Catalyzed by a Mo(VI) Dioxo(pyridine-2,6-dicarboxylato) Complex

The need for renewable resources to displace petrochemical feedstocks is of great interest. Deoxydehydration (DODH) reduces biomass-derived polyols and diols to alkenes and dienes, possibly moving alkene production closer to carbon-neutral sources. We report the DODH of numerous aromatic, aliphatic, and biomass model diols by a dioxo-Mo(VI) catalyst, MoO2(pyridine-2,6-dicarboxylato)(HMPA). Optimal reaction conditions were found using PPh3 and 1-phenyl-1,2-ethanediol yielding up to 93% styrene. Mechanistic studies using in situ infrared spectroscopy support a biexponential kinetic regime where the rate constant of the rate-determining step is ∼5 × 10–5 s–1. DFT calculations support the kinetic studies and suggest that the largest kinetic barrier is a proton transfer from the substrate to a metal–oxo bond during diolate formation.

Recent Advances in Defect-Engineered Transition Metal Dichalcogenides for Enhanced Electrocatalytic Hydrogen Evolution: Perfecting Imperfections.

Switching to renewable, carbon-neutral sources of energy is urgent and critical for climate change mitigation. Despite how hydrogen production by electrolyzing water can enable renewable energy storage, current technologies unfortunately require rare and expensive platinum group metal electrocatalysts, which limit their economic viability. Transition metal dichalcogenides (TMDs) are low-cost, earth-abundant materials that possess the potential to replace platinum as the hydrogen evolution catalyst for water electrolysis, but so far, pristine TMDs are plagued by poor catalytic performances. Defect engineering is an attractive approach to enhance the catalytic efficiency of TMDs and is not subjected to the limitations of other approaches like phase engineering and surface structure engineering. In this minireview, we discuss the recent progress made in defect-engineered TMDs as efficient, robust, and low-cost catalysts for water splitting. The roles of chalcogen atomic defects in engineering TMDs for improvements to the hydrogen evolution reaction (HER) are summarized. Finally, we highlight our perspectives on the challenges and opportunities of defect engineering in TMDs for electrocatalytic water splitting. We hope to provide inspirations for designing the state-of-the-art catalysts for future breakthroughs in the electrocatalytic HER.

Advances in technology and utilization of natural resources for achieving carbon neutrality and a sustainable solution to neutral environment

The greatest environmental issue of the twenty-first century is climate change. Human-caused greenhouse gas emissions are increasing the frequency of extreme weather. Carbon dioxide (CO2) accounts for 80% of human greenhouse gas emissions. However, CO2 emissions and global temperature have risen steadily from pre-industrial times. Emissions data are crucial for most carbon emission policymaking and goal-setting. Sustainable and carbon-neutral sources must be used to create green energy and fossil-based alternatives to reduce our reliance on fossil fuels. Near-real-time monitoring of carbon emissions is a critical national concern and cutting-edge science. This review article provides an overview of the many carbon accounting systems that are now in use and are based on an annual time frame. The primary emphasis of the study is on the recently created carbon emission and eliminating sources and technology, as well as the current application trends for carbon neutrality. We also propose a framework for the most advanced naturally available carbon neutral accounting sources capable of being implemented on a large scale. Forming relevant data and procedures will help the “carbon neutrality” plan decision-making process. The formation of pertinent data and methodologies will give robust database support to the decision-making process for the “carbon neutrality” plan for the globe. In conclusion, this article offers some opinions, opportunities, challenges and future perspectives related to carbon neutrality and carbon emission monitoring and eliminating resources and technologies.

A review of hydrogen production from bio-energy, technologies and assessments

Abstract The earth natural carrying capacity is being surpassed, and there is an urgent need to develop new alternatives, notably in regards to energy supplies, carbon dioxide emissions, and nitrogen supplies to the ecosystem. Hydrogen gas, produced from renewable energy by water electrolysis, may serve as a platform molecule for the 21st century low-carbon economy and electrification. The ability to utilise hydrogen metabolic processes is quite diverse, and this offers up a vast array of avenues for innovative biotechnological advancements and applications. A strategy focusing on the major role of hydrogen throughout the production of bio-based foundational element compounds through the hydrocarbon pathway would avoid the inherent low economic value of hydrocarbons in favour of products with greater value. Furthermore, hydrogen could serve as a crucial carbon-neutral source for the manufacture of third-generation proteins while allowing carbon capture and nutritional recovery immediately at the site of emission. Using these methods to deal with the seasonal changes in renewable energy sources makes the use of alternative energy as efficient as possible. The outcomes demonstrated the production technologies of bio-hydrogen is a good way to make renewable hydrogen that is both cost-effective and good for the environment compared to other ways of making hydrogen.

Feasibility and viability of procuring biohydrogen from microalgae: An emerging and sustainable energy resource technology

Abstract As the world’s population is increasing at an unprecedented rate, causing a severe impact on the limited and depleting petroleum reserves by their overexploitation and consumption. It is estimated that due to increasing socioeconomic and infrastructural advancements, we have already consumed about 50% of the petroleum reserves. Furthermore, the excessive usage of fossil fuels is believed to be a potential cause of global warming and a threat to environmental sustainability. This led the researchers to explore and study renewable and carbon-neutral sources of energy, which can be optimized as per the requirement and should be economically viable. Microalgae stand out momentous and materialized as feedstock to get all that we need at a single platform. Microalgae are the primary producers that utilize Carbone dioxide CO2 and light for their growth. They can be grown in freshwater, saline water, and even in wastewaters due to their disparate biochemical metabolism. This urged microalgae to be exploited for obtaining various renewable energy-based fuels, as it has the following significant features: potential for CO2 fixation; high biomass growth rate; its capacity to store carbon in lipids and carbohydrates to produce biofuels (bioethanol, biodiesel, biohydrogen, and biomethane). Recently, Hydrogen have gained interest as one of the most environmental friendly fuel. Hydrogen has numerous merits as compared with others fuel. The range of energy content is 120–142 MJ/Kg and it has high content (142 MJ/kg) as comparing with energy content of gasoline (47 MJ/kg), methane (56 MJ/kg), and natural gas (54 MJ/kg) while, the energy density is 8.5–10.1MJ/L. Furthermore, the yield is 92–485 mL/gVS and cetane number 50-53. This mini review provides an insight about the processes of biophotolysis, and fermentation utilized in the production of biohydrogen utilizing microalgae. It will incorporate the recent developments and innovations in biohydrogen production using microalgae. It will also give an overview of the challenges encountered in the production routes and the future perspectives.

Wind Microgeneration Strategy for Meeting California’s Carbon Neutral Grid Goal

As California’s Renewables Portfolio Standard continues to phase power production from fossil fuels, carbon neutral sources will need to be implemented. This sets small-scale wind production and battery storage in a position to integrate into current grid infrastructure as means of production. This would be an “E Pluribus Unum” approach where many decentralized small production and storage units would act in combination to provide a stable grid. This is often referred to as distributed generation (DG). By distributing the grid’s production in this manner and designating predetermined regional hubs for control (in the event of a fractured grid due to natural disaster), the state and its residents will be able to maintain power for critical infrastructure and basic utilities. This work presents, in detail, a sustainable plan for achieving carbon neutral Californian grid by 2045.

An Application of Instantaneous Spectral Entropy for the Condition Monitoring of Wind Turbines

For economic and environmental reasons, the use of renewable energy sources is a key aspect of the ongoing transition to a sustainable industrialised society. Wind energy represents a major player among these natural, carbon-neutral sources. Nevertheless, wind turbines are often subject to mechanical faults, especially due to ageing. To alleviate Operation and Maintenance costs, Vibration-Based Inspection and Condition Monitoring have been proposed in recent times. This research proposes Instantaneous Spectral Entropy and Continuous Wavelet Transform for anomaly detection and fault diagnosis, departing from gearbox vibration time histories. The approach is validated on experimental data recorded from a turbine suffering bearing failure and total gearbox replacement. From a computational point of view, the proposed algorithm was found to be efficient and therefore even potentially applicable for real-time monitoring.

Green pathways for urea synthesis: A review from Australia's perspective

• Historical trend of the unsustainable fertilizer manufacturing should pursue greener pathways. • Green ammonia feedstock is critical but should be complemented with non-fossil CO 2 sources. • Three potential non-fossil-fuel CO 2 resources are discussed and evaluated in Australia. • Carbon-neutral CO 2 from biomass, renewable methane, or direct air capture may fit the criteria. • Proper energy management systems are essential for process synchronization and optimization. This paper discusses the status of the global fertilizer industry with a primary focus on Australian market. The conventional energy- and carbon-intensive ammonia production industry is taking serious steps in transforming to more environmentally benign pathways via utilising ‘green’ hydrogen (hydrogen production via water electrolysis powered by renewable energy) feedstock into their production process and utilizing more of the CO 2 by-product into downstream processes such as urea production. However, it is very challenging for ammonia and other fertilizer production routes to use ‘green’ pathway to completely decarbonize agriculture and food industry. Here, we argue that urea synthesis can only be considered as a ‘green’ technology if ammonia feedstock is produced via ‘green’ pathway and the CO 2 feedstock comes from non-fossil-fuel and carbon-neutral sources. Three possible resources for carbon-neutral CO 2 are identified and discussed within Australia's context: from biomass, renewable methane, and from direct air carbon capture (DAC). Each of these carbon-neutral CO 2 routes has many opportunities and challenges that may affect the cost of production, but the trajectory urea prices and growing market demand if supported by an adequate government regulatory framework would be able to make the ‘green’ urea production cost affordable. Achieving this goal however would require proper energy management systems to synchronize and optimize such a multi-player orientation for a common objective of maximizing the penetration of renewable sources at competitive costs. In this review, it is emphasized that this challenge could be addressed more effectively via a rigours intelligent energy network (IEN) by managing the dynamics of the supply and demand, integrating reliable storage systems, reclaiming the waste heat, and improving process efficiencies. Local ‘green’ urea production at competitive costs would help Australia realizing ambitions to become a leading green fertilizer and renewable energy exporter in the region.