Cost-effective Decarbonisation Research Articles

A new strategy to prepare MLG-SiCw/SiCp composites via three-roll milling exfoliation and catalytical-conversion for advanced refractories

Cost-effective decarbonization and structural strengthening of carbon-containing refractory materials are crucial for the development of low-carbon steel (LCS) and ultra-low-carbon steel (ULCS) technologies. In this study, a carbonaceous-ceramic reinforcement assembly structure composed of multilayer graphenes and silicon carbide whiskers/particles (MLGs-SiCw/SiCp) has been successfully designed and fabricated. By employing three-roll milling (TRM) for low-cost exfoliation of expanded graphite (EG) into MLGs in a phenolic resin (PF) medium, we optimized the exfoliation cycles to fine-tune the morphology of MLGs. Subsequently, the catalytical solid-state conversion of PF/MLGs reacting with Si into SiCw/SiCp at 1400 °C, under varying C/Si molar ratios and catalyst contents, not only retained the structural integrity of MLGs but also embedded them within a novel SiCw/SiCp composite matrix. Our research elucidates the catalytic conversion mechanism, underscoring the significant role of nickel catalysts in promoting efficient SiC conversion. This work offers a promising pathway for developing high-performance, economical, low-carbon refractories.

High-Temperature Heat Pumps for Electrification and Cost-Effective Decarbonization in the Tissue Paper Industry

High-Temperature Heat Pumps for Electrification and Cost-Effective Decarbonization in the Tissue Paper Industry

Decarbonizing the US Energy System

Recent rapid and unexpected cost reductions in decarbonization technologies have accelerated the cost-effective decarbonization of the US economy, with greenhouse gas (GHG) emissions falling by 20% from 2005 to 2020. The literature on US economy-wide decarbonization focuses on maximizing long-term GHG emissions reduction strategies that rely mostly on renewable energy expansion, electrification, and efficiency improvements to achieve net-zero GHG emissions by 2050. While these studies provide a valuable foundation, further research is needed to properly support decarbonization policy development and implementation. In this review, we identify key decarbonization analysis gaps and opportunities, including issues related to cross-sectoral linkages, spatial and temporal granularity, consumer behavior, emerging technologies, equity and environmental justice, and political economy. We conclude by discussing the implications of these analysis gaps for US decarbonization pathways and how they relate to challenges facing major global emitters.

Effects of emissions caps on the costs and feasibility of low-carbon hydrogen in the European ammonia industry

The European ammonia industry emits 36 million tons of carbon dioxide annually, primarily from steam methane reforming (SMR) hydrogen production. These emissions can be mitigated by producing hydrogen via water electrolysis using dedicated renewables with grid backup. This study investigates the impact of decarbonization targets for hydrogen synthesis on the economic viability and technical feasibility of retrofitting existing European ammonia plants for on-site, semi-islanded electrolytic hydrogen production. Results show that electrolytic hydrogen cuts emissions, on average, by 85% (36%-100% based on grid price and carbon intensity), even without enforcing emission limits. However, an optimal lifespan average well-to-gate emission cap of 1 kg carbon dioxide equivalent (CO2e)/kg H2 leads to a 95% reduction (92%-100%) while maintaining cost-competitiveness with SMR in renewable-rich regions (mean levelized cost of hydrogen (LCOH) of 4.1 euro/kg H2). Conversely, a 100% emissions reduction target dramatically increases costs (mean LCOH: 6.3 euro/kg H2) and land area for renewables installations, likely hindering the transition to electrolytic hydrogen in regions with poor renewables and limited land. Increasing plant flexibility effectively reduces costs, particularly in off-grid plants (mean reduction: 32%). This work guides policymakers in defining cost-effective decarbonization targets and identifying region-based strategies to support an electrolytic hydrogen-fed ammonia industry.

The role of regional renewable energy integration in electricity decarbonization—A case study of Japan

Decarbonization strategies depend critically on the integration of region-specific renewable energy and social acceptance, yet their roles still need to be clarified. This study designs a regional-integrated electricity system and assesses the impact of regional decisions associated with renewable energy on cost-effective national decarbonization, using Japan as a case study owing to its active engagement in regional decarbonization. A high spatial resolution renewable electricity system model that explicitly considers all 1741 Japanese municipalities and employs a hierarchical optimization approach is developed. Based on the model, the opportunity cost of limiting renewable energy development is quantified for 30 representative municipalities. The results highlight that restrictions on municipal renewable energy can increase annual system costs by hundreds of millions of euros and national electricity costs by up to 0.4%, although it varies by region and energy source. This suggests that widespread opposition to renewables could be a significant barrier to cost-effective decarbonization. However, the impact of solar photovoltaic (PV) tends to be slight. In conclusion, investments in social acceptance of region-specific renewables can minimize opportunity losses and reduce system costs. Nonetheless, relocating the project to another region is possibly more cost-effective for solar PV.

Bending the emission curve ― The role of renewables and nuclear power in achieving a net-zero power system in India

As India is on the cusp of a significant energy transition, this study explores the future pathways towards a decarbonised Indian power sector by using various plausible options such as variable renewable energy technologies, nuclear power, energy storage and green H2. The TIMES-based optimisation model with an hourly temporal resolution has been run for fifty years, from 2020 to 2070, to determine the optimal planning and operation of the Indian power sector. The model includes not only the long-term planning of the Indian power sector but also considers the short-term operational flexibility constraints of the thermal generators, grid-scale storage as balancing units, and the demand for green H2 derived from renewable energy sources (RES). Base-case model results indicate that the average coal capacity and CO2 emissions would continue to rise in the short term, reaching a peak by 2040 before gradually declining. However, the overall cost of transition is relatively independent of the technology choice, where the rise in fuel cost in the high nuclear scenario would be offset by the increased capital investment in a renewable-dominated scenario. The average annual investment required to achieve a zero-emission power sector is approximately USD 550 billion. The average ex-bus cost of electricity would increase from USD 36 per MWh in 2020 to about USD 50 per MWh in 2070. This analysis will provide valuable insights to all the relevant stakeholders in emerging and developing economies such as India to explore future cost-effective decarbonisation pathways of the power sector.

The CCS greensand project: CO2 pilot injection and monitoring

The CCS greensand project: CO2 pilot injection and monitoring

The role of electricity market design for energy storage in cost-efficient decarbonization

The role of electricity market design for energy storage in cost-efficient decarbonization

Integrated enterprise input-output and carbon emission pinch analysis for carbon intensity reduction in edible oil refinery

It is important to properly account for the emissions contribution of process units in order to develop cost-effective industrial decarbonization strategies. However, there is limited literature on this topic in the edible oil refining sector. This work addresses this research gap by developing a novel systematic technique for assessing decarbonization options in the palm oil refining process. This technique combines enterprise input-output analysis (EIOA) with graphical carbon emission pinch analysis (CEPA) into a unified approach to examining cost-effective decarbonization measures. Results show that the average carbon intensity of the system was 0.0432 kg CO2/$ while the total carbon footprint was 2339.97 kg CO2. Palm fatty acid distillate (PFAD) has the highest carbon intensity contribution (0.0392 kg CO2/$) among the multiple products. Four scenarios to achieve a 20% reduction in CO2 emissions based on heat integration and process changes were examined. Economic evaluation was also conducted for each proposed strategy.

Geographic carbon accounting: The roadmap for achieving net-zero emissions in Mauritius Island

Significant climate finance gaps exist for small islands in transitioning to net zero, as climate commitments far outweigh the government budget and international financing. To create alignment between resource allocation and climate commitments, a roadmap for strategic and cost-effective decarbonization is of supreme importance. This paper presents a geographic carbon accounting model which incorporates emissions from electricity, transportation, food systems, and human respiration, whilst accounting for the carbon uptake by the terrestrial biosphere in view of identifying high-intensity aggregated emissions estimated in the range of 200–215 ktCO2e in the coastal and inland urban regions of the remote island of Mauritius. An estimated 4641 ktCO2e, representing 79.4% of overall emissions, has been observed to originate from buildings, food, and waste systems. About 1150 ktCO2e, accounting for a share of 19.7%, is derived from transport systems. The study advocates for the enhanced participation of local authorities to better contribute to climate governance, whilst supporting legislative, financial, technological, and behavioural reforms. Despite the relatively low sequestration potential of forests replacing all non-habitable lands, which is estimated at 1002 ktCO2e and representing about 17.1% of annual net emissions, afforestation programmes are encouraged owing to multiple ecosystem services provided by trees.

Cost effective decarbonisation of blast furnace – basic oxygen furnace steel production through thermochemical sector coupling

We present here a first-principles study of the sector coupling between a thermochemical carbon dioxide (CO2) splitting cycle and existing blast furnace – basic oxygen furnace (BF-BOF) steel making for cost-effective decarbonisation. A double perovskite, Ba2Ca0.66Nb0.34FeO6, is proposed for the thermochemical splitting of CO2, a viable candidate due to its low reaction temperatures, high carbon monoxide (CO) yields, and 100% selectivity towards CO. The CO produced by the TC cycle replaces expensive metallurgical coke for the reduction of iron ore to metallic iron in the blast furnace (BF). The CO2 produced from the BF is used in the TC cycle to produce more CO, therefore creating a closed carbon loop, allowing for the decoupling of steel production from greenhouse gas emissions. Techno-economic analysis of the implementation of this system in UK BF-BOFs could reduce steel sector emissions by 88% while increasing the cost-competitiveness of UK steel on the global market through cost reduction. After five years, this system would save the UK steel industry £1.28 billion while reducing UK-wide emissions by 2.9%. Implementation of this system in the world's BF-BOFs could allow the steel sector to decarbonise in line with the Paris Climate Agreement to limit warming to 1.5 °C.

Technological avenues and market mechanisms to accelerate methane and nitrous oxide emissions reductions.

Strategies targeting methane (CH4) and nitrous oxide (N2O) emissions are critical to meeting global climate targets. Existing literature estimates the emissions of these gases from specific sectors, but this knowledge must be synthesized to prioritize and incentivize CH4 and N2O mitigation. Accordingly, we review emissions sources and mitigation strategies in all key sectors (fuel extraction and combustion, landfilling, agriculture, wastewater treatment, and chemical industry) and the role of carbon markets in reducing emissions. The most accessible reduction opportunities are in the hydrocarbon extraction and waste sectors, where half (>3 Gt-CO2e/year) of the emissions in these sectors could be mitigated at no net cost. In total, 60% of CH4 emissions can be mitigated at less than $50/t-CO2. Expanding the scope of carbon markets to include these emissions could provide cost-effective decarbonization through 2050. We provide recommendations for carbon markets to improve emissions reductions and set prices to appropriately incentivize mitigation.

Environmental and economic optimization and prioritization tool-kit for residential building renovation strategies with life cycle approach

The most recent regulations, as well as the scientific studies, remark the importance of the evaluation of the entire life cycle on building renovations, relative to the environmental impact and economic feasibility, making the Life Cycle Assessment (LCA) the prioritizing analysis. The objective of the study is to develop a simplified methodology for the environmental and economic assessment of residential building renovations with life cycle approach. For this, a script-based tool-kit is developed: the first tool optimizes the thickness of envelope insulation based strategies; the second tool is for the prioritization of strategies by assessing their environmental performance and economic feasibility. In order to follow the objective, the development of the two tools is presented: both tools follow a parallel scheme where the input parameters are required by an excel file and the calculation script provides the results automatically by exporting the results excel file. The evaluation provides the quantification of the relative environmental improvement with the net energy ratio (NER), and the economic feasibility by the financial indicator of internal rate of return (IRR). The tool-kit is applied in a case study of a multifamily residential building. The results show, on the one hand, that the usability of the tool-kit can be determinant in the decision-making of stakeholders; and in the other hand, the importance of carrying out a dynamic assessment, taking into account the variation of the results caused by the uncertain parameters that differ in time. Moreover, the tool-kit can assist the development of cost-effective decarbonisation strategies.

Modelling the end-use performance of alternative fuel properties in flex-fuel vehicles

Renewable fuels and fuel-optimized engines play a key role in the time- and cost-effective decarbonization of current mobility. The present work introduces a state-of-the-art mathematical model that allows for the first time an accurate estimation of fuel consumption in flex-fuel vehicle engines by considering the impact of the most significant fuel properties exclusively. These engines are optimized to a higher concentration of non-drop-in fuels such as E85. Based on the literature data, a matrix was built with fuel properties as multiple independent variables and fuel consumption as a response variable. A multilinear regression with quantitative analysis was applied to develop a fuel consumption model for FFVs. The most significant fuel properties turned out to be octane sensitivity, vapor pressure, lower heating value, and density. All properties in the final model have a unique and important impact on fuel consumption, secured by extremely low p-values (P ≪ 1 %). The model reached very high accuracy represented by R-Square of 0.994, which turned into 1.41 % of the average absolute error in internal validation and only 1.9 % in external validation. The present study shows that in all alternative fuel cases, flex-fuel vehicles performed with better fuel economy than standard spark-ignition light-duty vehicles. Moreover, high concentration alcohol blends reduce energy consumption as well as tank-to-wheel CO2 emissions despite their higher fuel consumption. The developed model can be applied to fuel consumption estimations in FFVs from single chemical compounds to commercial fuel products including new fuel blends.

Machine learning analysis on the impacts of COVID-19 on India's renewable energy transitions and air quality.

India is severely affected by the COVID-19 pandemic and is facing an unprecedented public health emergency. While the country’s immediate measures focus on combating the coronavirus spread, it is important to investigate the impacts of the current crisis on India’s renewable energy transition and air quality. India’s economic slowdown is mainly compounded by the collapse of global oil prices and the erosion of global energy demand. A clean energy transition is a key step in enabling the integration of energy and climate. Millions in India are affected owing to fossil fuel pollution and the increasing climate heating that has led to inconceivable health impacts. This paper attempts to study the impact of COVID-19 on India’s climate and renewable energy transitions through machine learning algorithms. India is observing a massive collapse in energy demand during the lockdown as its coal generation is suffering the worst part of the ongoing pandemic. During this current COVID-19 crisis, the renewable energy sector benefits from its competitive cost and the Indian government’s must-run status to run generators based on renewable energy sources. In contrast to fossil fuel-based power plants, renewable energy sources are not exposed to the same supply chain disruptions in this current pandemic situation. India has the definite potential to surprise the global community and contribute to cost-effective decarbonization. Moreover, the country has a good chance of building more flexibility into the renewable energy sector to avoid an unstable future.

Gear up for Green Steel

Steel is the world's largest materials industry and is ubiquitous in everything from car bodies to construction and wind turbines. Therefore, its cost-effective decarbonisation is integral to the global net-zero agenda, as well as for individual companies that have themselves set similar ambitions. Last year a breakthrough proved it's technologically possible to decarbonise the versatile alloy. HYBRIT, a consortium consisting of Vattenfall, steel producer SSAB and miner LKAB, produced the first ever fossil-fuel free steel using green hydrogen. HYBRIT's aspiration isn't unique. Driven by the SteelZero initiative, set up in 2020 by The Climate Group to drive action to decarbonise the sector, key industry stakeholders have made a flurry of commitments and investments to reach this milestone by 2050. Industry momentum is expected to continue in 2022 with the first industrial pilot projects expected by the middle of the decade.

INTERCHANGEABILITY AND STANDARDIZATION OF THE PARAMETERS OF COMBUSTIBLE GASES WHEN USING HYDROGEN

Introduction and purpose of the study: The paper presents results of studies aimed to provide a rationale for the possibility of a gradual transition to hydrogen combustion in gas supply to domestic and commercial consumers without changes in the design and operation of burners. For this purpose, we have considered tasks of determining the indicators of interchangeability for natural gas and its mixtures with hydrogen. The main characteristics of combustible gases with various hydrogen content in a mixture have been studied. We have established the impact of the hydrogen content on the heat rate, emissions of harmful substances, as well as light back and flame lift phenomena. We have also analyzed the available interchangeability criteria and their applicability when using natural gas/hydrogen mixtures. The impact of the hydrogen content on the radiation heat transfer in the furnaces of gas equipment is described in the paper for the first time. Methods: The methodology of the paper is based on a critical analysis of available literature data on combustible gases interchangeability as well as theoretical and experimental studies performed by the authors. We have derived dependencies that allow us to determine the possibility of gas equipment transition to the combustion of natural gas/hydrogen mixtures. We have also developed recommendations on the permissible hydrogen content in a natural gas/ hydrogen mixture that would ensure the efficient, safe, and green use of such fuel in domestic and commercial heating units. Results: Scientific findings and practical results of the study make it possible to implement partial gradual costeffective decarbonization in the area of gas fuel utilization as an intermediate stage of transition to more extended hydrogen combustion.

Resource-optimised generation dispatch strategy for district heating systems using dynamic hierarchical optimisation

District heating is expected to play an essential role in the cost-effective decarbonisation strategy of many countries. Resource-optimised management of district heating networks depends on a wide range of factors, including demand forecasting, operational flexibility, and increasingly volatile market conditions. However, traditional operations often still rely on static models and rather simple heuristics, while holistic optimisation requires dynamic cross-domain interoperability to allow the consideration of all these factors. This paper demonstrates a proof-of-concept for a knowledge graph based optimisation problem to minimise total heat generation cost for a district heating provider. The optimisation follows a hierarchical approach based on a merit-order principle and is embedded in a model predictive control framework to allow the system to incorporate most recent information and react to disturbances promptly. A detailed sensitivity study is conducted to identify key model parameters and assess the impact of anticipated changes in regulation and market conditions. Simulation-based optimisation is used to determine the short-term heat generation mix based on data-driven gas consumption models and day-ahead forecasts for the network’s energy demand and grid temperatures. Seasonal autoregressive integrated moving average models with exogenous predictor variables are found to be sufficiently accurate and precise. The effectiveness of the approach is demonstrated for a case study of an existing heating network of a midsize town in Germany, where a reduction of approximately 20% and 40% compared to baseline operational data is obtained for operating cost and CO2 emissions, respectively.

Cost-effectiveness of decarbonisation options for the vegetable-oil and -fat industry in the Netherlands

There is significant emission reduction potential in the Dutch vegetable oil and fat industry, which consists of seven companies each producing more than 10 kt CO2 per year, emitting a total of 0.36 Mt CO2 in 2018. Marginal Abatement Cost (MAC) curves are constructed to provide an overview of the most cost-effective decarbonisation options. Both energy efficiency technologies and alternative heating systems are combined in order to achieve technological configurations for full decarbonisation of this industry. Energy consumption for vegetable oil processing can be reduced by 44% for rapeseed oil, 45% soybean oil, and 57% for palm oil. Vertical Ice Condensing is the most cost-effective decarbonisation option, while biogas boilers are the most cost-effective alternative heating systems that can supply energy in all stages of production. However, the availability of processing residues limits the energy substitution possible with biogas boilers. Electric boilers are therefore required to deliver the residual energy necessary to realise zero carbon emissions. Together the cost-effective decarbonisation options can abate between 38% and 40% of the total CO2 emissions by 2020 and 2030 respectively.

Integration of Photovoltaic Electricity with Shallow Geothermal Systems for Residential Microgrids: Proof of Concept and Techno-Economic Analysis with RES2GEO Model

The European Union aims to reduce Greenhouse Gas (GHG) emissions by 55% before 2030 compared to 1990 as a reference year. One of the main contributions to GHG emissions comes from the household sector. This paper shows that the household sector, when organised into a form of prosumer microgrids, including renewable sources for electric, heating and cooling energy supply, can be efficiently decarbonised. This paper investigates one hypothetical prosumer microgrid with the model RES2GEO (Renewable Energy Sources to Geothermal). The aim is to integrate a carbon-free photovoltaic electricity source and a shallow geothermal reservoir as a heat source and heat sink during the heating and cooling season. A total of four cases have been evaluated for the Zagreb City location. The results represent a balance of both thermal and electric energy flows within the microgrid, as well as thermal recuperation of the reservoir. The levelised cost of energy for all cases, based on a 20-year modelling horizon, varies between 41 and 63 EUR/MWh. On the other hand, all cases show a decrease in CO2 emissions by more than 75%, with the best case featuring a reduction of more than 85% compared to the base case, where electricity and gas for heating are supplied from the Distribution System Operator at retail prices. With the use of close integration of electricity, heating and cooling demand and supply of energy, cost-effective decarbonisation can be achieved for the household sector.