China's cement industry accounts for over half of global production and contributes 8% of global CO2 emissions, making its decarbonization critical for achieving climate targets. While carbon capture and storage (CCS) and carbon capture and utilization (CCU) are essential deep decarbonization technologies, existing research has not adequately addressed the regional and temporal variations needed for optimal pathway selection across China's diverse provinces. This study develops a comprehensive whole-systems optimization model to design provincial-scale decarbonization pathways for China's cement industry from 2025 to 2060. The model reveals significant spatial and temporal heterogeneity in optimal technology combinations. Before 2050, traditional cement processes integrated with CCS (TCP-CCS) represent the dominant bridging technology for low-carbon transition. However, reaching carbon neutrality by 2060 necessitates an eventual shift toward widespread deployment of novel chemical proc... [more]

Conventional urea production is a centralized and fossilintensive process associated with significant greenhousegas (GHG) emissions and limited flexibility for deep decarbonization. As an alternative, the Integrated COnversion of NItrate and Carbonate steams (ICONIC) project is developing innovative electrochemical urea (eurea), via the co-electroreduction of nitrogen and carbon sources using renewable power. While recent research advances in electrocatalysis have demonstrated promising Faradaic efficiencies (FE) toward urea, the design of electrochemical systems involves inherent tradeoffs between key performance indicators (KPIs) such as current density, cell voltage, and FE. Crucially, the implications of electrolyzerlevel performance on plantlevel economics and environmental impacts remain poorly understood. To address this gap, we integrate process modelling with technoeconomic and lifecycle assessment (TEA-LCA) to evaluate the trade-offs of KPIs from a process systems per... [more]

This study presents a mixed-integer bilinear optimization model for the cost-optimal design of a Northern European hydrogen supply chain with integrated CCS, focusing on exports from Norway to Germany and CO2 sequestration in Norway. The model is formulated as a superstructure problem and implemented in Pyomo, considering multiple locations for infrastructure nodes and transport options for hydrogen, wood chips, and CO2.

This study presents a mixed-integer bilinear optimization model for the cost-optimal design of a Northern European hydrogen supply chain with integrated CCS, focusing on exports from Norway to Germany and CO2 sequestration in Norway. The model is formulated as a superstructure problem and implemented in Pyomo, considering multiple locations for infrastructure nodes and transport options for hydrogen, wood chips, and CO2.

CCS is a well investigated and fairly promising technology for reducing the emission of carbon dioxide (CO2) to the atmosphere. However, it is rarely implemented in the industry due to its high cost. Therefore, this work proposes a cost optimized CCS chain which can be operated flexibly and safely. For the capture process a post combustion chemical absorption technology is chosen due to its retrofitting possibility to already existing power plants and its low capture cost. In order to find a cost efficient absorption process for different scenarios, the five most promising process configurations from previous work are combined into a superstructure in a rigorous rate based reactive Aspen Plus model. This in turn is optimized by a two-stage stochastic programming approach in Matlab. The optimal supply chain network is identified by a tailor made transshipment model implemented in GAMS, which accounts for the most promising transportation units, storage sites as well as direct utilizatio... [more]

Shipping is the backbone of global freight. However, due to its currently strong reliance on fossil fuels, it accounts for 3 % of global greenhouse gas emissions, highlighting both the need and challenge of achieving the required rapid decarbonization. Over the past decade, Onboard carbon capture and storage (OCCS) has gained interest as a potential mitigation strategy while alternative fuels continue to develop. However, several capture technologies could be considered to capture the resulting CO2. In order to identify the most promising ones, this study performs a screening of different capture technologies (including absorption, membrane-assisted liquefaction, adsorption-assisted liquefaction, calcium-looping) through the case of a combination carrier under retrofit and newbuilding scenarios.
Overall, the results indicate that retrofit installations can reduce CO2 emissions by at least 45 %, even when using the existing ship power system. Once the utility (heat and power) is assum... [more]

The integration of carbon capture and storage (CCS) into coal and biomass co-firing systems (CBCCS) offers a promising solution for reducing carbon emissions in electricity generation. This study evaluates hypothetical scenarios in Malaysia and Indonesia, focusing on techno-economic-environmental transparency. The analysis shows a negligible change in plant net efficiency (~1%) across biomass co-firing ratios of 5-20% in both countries. The capture penalty increases at higher biomass ratios, particularly at 20% co-firing, due to higher auxiliary power demands and steam extraction. As biomass share increases, net CO2 emissions decrease by an average of 43% in Malaysia and 34% in Indonesia. Economic evaluations show a positive revenue increase for Malaysia at a 20% co-firing ratio, while Indonesia faces a revenue deficit (0.6%) under the same condition, mainly due to an unattractive carbon price and feed-in tariff from 2027 onward. Malaysia faces a higher risk of stranded assets due to e... [more]

In response to the global imperative to address climate change, this research focuses on enhancing the transparency and efficiency of the Carbon Capture Utilization and Storage (CCUS) supply chain under carbon tax. We propose a decision-making framework that integrates the CCUS supply chain's optimization model, emphasizing carbon tax policies, with a blockchain network. Smart contracts play a pivotal role in automating the exchange and utilization of carbon emissions, enhancing the digitalization of the CCUS supply chain from source to sink. This automation facilitates seamless matching of carbon sources with sinks, efficient transfer of emissions and funds besides record-keeping of transactions. Consequently, it improves the monitoring, reporting, and verification processes within the CCUS framework, thereby simplifying compliance with regulatory mandates for net emission reductions and carbon taxation policies. By eliminating reliance on third-party verifiers, our blockchain-based... [more]

Inspired by Nature, we propose that synergies between biorefinery and mineral refinery can be exploited so that at least a part of the carbon is captured before being released to the atmosphere. In doing so, carbon is captured not only from CO2 but also from biomass and developing more such processes may be the cornerstone for controlling CO2 emissions. A comparison of circular economy in traditional biorefineries and bio-mineral refineries is done by using general chemical formulas and it is shown that the bio-mineral refinery captures carbon. In this work, we have shown that Serpentine may be used to partially neutralise biomass pyrolysis oil. The extracted oil may be used as feedstock to produce downstream chemicals and further studies are required to produce the same.

There is a need to drastically reduce greenhouse gas emissions. While significant progress has been made in electrifying transport, heavy duty transportation and aviation are not likely to be capable of electrification in the near term, spurring significant research into biofuels. When coupled with carbon capture and storage, biofuels can achieve net-negative greenhouse gas emissions via many different conversion technologies such as fermentation, pyrolysis, or gasification to produce ethanol, gasoline, diesel, or jet fuel. However, each pathway has a different efficiency, capital and operating costs, and potential for carbon capture, making the optimal pathway dependent on policy and spatial factors. We use the Integrated Markal-EFOM System model applied to the USA, adding a rich suite of biofuel and carbon capture technologies, region-specific CO2 transportation and injection costs, and government incentives from the Inflation Reduction Act. We find that under current government ince... [more]

This paper discusses the symbiotic relationship between technology research and development (R&D) and energy transition modeling. On the one hand, energy system modeling has a noteworthy history of providing macroscopic views and critical insights concerning the role that myriad technologies may play in the future energy system. On the other hand, R&D can lead to both incremental and disruptive technological advances that can shape energy transition planning. In this work, we focus on the bidirectional flow of information between the two with a particular focus on highlighting the potential role of carbon capture, storage, and sequestration technology.

Onshore gas-to-wire is considered for 6.5 MMSm3/d of natural gas, with 44% mol carbon dioxide coming from offshore deep-water oil and gas fields. Base-case GTW-CONV is a conventional natural gas combined cycle, with a single-pressure Rankine cycle and 100% carbon dioxide emissions. The second variant, GTW-CCS, results from GTW-CONV with the addition of post-combustion aqueous monoethanolamine carbon capture, coupled to carbon dioxide dispatch to enhance oil recovery. Despite investment and power penalties, GTW-CCS generates both environmental and economic benefits due to carbon dioxide’s monetization for enhanced oil production. The third variant, GTW-CCS-EGR, adds two intensification layers over GTW-CCS, as follows: exhaust gas recycle and a triple-pressure Rankine cycle. Exhaust gas recycle is a beneficial intensification for carbon capture, bringing a 60% flue gas reduction (reduces column’s diameters) and a more than 100% increase in flue gas carbon dioxide content (increases drivi... [more]

Capillary trapping of gas in porous media is important for many processes such as oil recovery and gas geo-sequestration. Foam can mitigate gravity override and viscous fingering of gas by reducing its relative permeability through gas trapping. However, there are limited studies dedicated to understanding how foam assists in gas trapping, the best mode of foam injection for trapping, and its application in geo-sequestration. This paper uses an initial−residual saturation analysis to investigate foam-assisted capillary trapping during the surfactant alternating gas (SAG) injection process in saline aquifers. More specifically, we studied the effects of pore geometric properties, in situ generated foam, and surfactant concentration on gas trapping efficiency and final residual gas saturation, Sgr. First, NMR surface relaxometry measurements were carried out on the rock samples to indicate the mean pore sizes of the rocks. A series of core flooding tests, equipped with resistivity measur... [more]

Carbon capture, utilisation and storage (CCUS) is a key area of research for CO2 abatement. To that end, CO2 capture, transport and storage has accrued several decades of development. However, for successful implementation of CCUS, utilisation or conversion of CO2 to valuable products is important. Electrochemical conversion of the captured CO2 to desired products provides one such route. This technique requires a cathode “electrocatalyst” that could favour the desired product selectivity. Copper (Cu) is unique, the only metal “electrocatalyst” demonstrated to produce C2 products including ethylene. In order to achieve high-purity Cu deposits, electrodeposition is widely acknowledged as a straightforward, scalable and relatively inexpensive method. In this review, we discuss in detail the progress in the developments of electrodeposited copper, oxide/halide-derived copper, copper-alloy catalysts for conversion of CO2 to valuable products along with the future challenges.

Due to significant temperature differences between the injected medium and in situ formation, injection of CO2 (as with water or other cold fluids) at depth induces thermal changes that must be accounted for a complete understanding of the mechanical integrity of the injection/storage system. Based on evaluations for the Northern Lights Carbon Capture and Storage (CCS) project, we focus on thermal effects induced on the caprock via conduction from cooling in the storage sands below. We investigate, using both analytical and numerical approaches, how undrained effects within the low permeability caprock can lead to volumetric contraction differences between the rock framework and the pore fluid which induce both stress and pore pressure changes that must be properly quantified. We show that such undrained effects, while inducing a more complicated response in the stress changes in the caprock, do not necessarily lead to unfavourable tensile conditions, and may, in fact, lead to increase... [more]

Biomass, a basic product of agriculture, is one of the main sinks of carbon in global cycle. Additionally, it can be used as a renewable source of energy, leading to depletion in CO2 emissions. The paper presents the results of estimations on the current and potential share of catch crop cultivation in climate change mitigation, in Poland, where the agricultural sector plays a significant economic role. The estimation of CO2 assimilation in biomass was performed on the basis of our own data on yields of commonly used catch crops, obtained in randomly selected 80 farms in Poland, and the content of carbon in the biomass. Calculation of energy potential of the biomass was conducted, assuming its conversion into biogas, on the basis of our own data on catch crop yields and the literature data on their biomethane potentials. The results have shown that catch crops in Poland, which are cultivated to an area of 1.177 mln ha sequestrate 6.85 mln t CO2 yr−1. However, considering the total area... [more]

Geological carbon storage is an effective method capable of reducing carbon dioxide (CO2) emissions at significant scales. Subsurface reservoirs with sealing caprocks can provide long-term containment for the injected fluid. Nevertheless, CO2 leakage is a major concern. The presence of abandoned wells penetrating the reservoir caprock may cause leakage flow-paths for CO2 to the overburden. Assessment of time-varying leaky wells is a need. In this paper, we propose a new semi-analytical approach based on pressure-transient analysis to model the behavior of CO2 leakage and corresponding pressure distribution within the storage site and the overburden. Current methods assume instantaneous leakage of CO2 occurring with injection, which is not realistic. In this work, we employ the superposition in time and space to solve the diffusivity equation in 2D radial flow to approximate the transient pressure in the reservoirs. Fluid and rock compressibilities are taken into consideration, which al... [more]

An essential line of worldwide research towards a sustainable energy future is the materials and processes for carbon dioxide capture and storage. Energy from fossil fuels combustion always generates carbon dioxide, leading to a considerable environmental concern with the values of CO2 produced in the world. The increase in emissions leads to a significant challenge in reducing the quantity of this gas in the atmosphere. Many research areas are involved solving this problem, such as process engineering, materials science, chemistry, waste management, and politics and public engagement. To decrease this problem, green and efficient solutions have been extensively studied, such as Carbon Capture Utilization and Storage (CCUS) processes. In 2015, the Paris Agreement was established, wherein the global temperature increase limit of 1.5 °C above pre-industrial levels was defined as maximum. To achieve this goal, a global balance between anthropogenic emissions and capture of greenhouse gase... [more]

Carbon Capture and Storage (CCS) is a technology for mitigating emissions from large point-source industries. In addition to the primary role of reducing carbon dioxide (CO2) in the atmosphere, CCS forms the basis for two large-scale negative emissions technologies by coupling geologic CO2 storage with bioenergy (BECCS) and direct air carbon capture (DACCS). Despite its inclusion within the United Nations Framework Convention on Climate Change (UNFCCC), CCS has been largely unsupported by UNFCCC delegates because of its association with fossil fuels. We evaluate data from surveys given since 2015 to UNFCCC delegates at the Conference of the Parties (COPs) to ascertain how attitudes about bioenergy, BECCS, and CCS may be changing within the UNFCCC. The results show a positive change in attitudes over time for both fossil CCS and BECCS. Using a unique data analysis method, we ascertain that, in some instances, popularity of BECCS increased due to an increased acceptance of CCS despite lo... [more]

The demand for carbon capture is increasing over time due to rising CO2 levels in the atmosphere. Even though fossil emission could be decreased or even eliminated, there is a need to start removing CO2 from the atmosphere. The removed CO2 could be either stored permanently to a reservoir (CCS, Carbon Capture and Storage) or utilized as a raw material in a long-lasting product (CCU, Carbon Capture and Utilization). The capture of CO2 could be done by direct air capture, or capturing CO2 from biogenic sources. Amine absorption is the state-of-the-art method to capture CO2, but it has some drawbacks: toxicity, high heat demand, and sorbent sensitivity towards impurities such as sulfur compounds and degradation in cyclic operation. Another potential solvent for CO2 could be water, which is easily available and safe to use in many applications. The problem with water is the poorer solubility of CO2, compared with amines, which leads to larger required flow rates. This study analyzed the te... [more]

Successful geological sequestration of carbon depends strongly on reservoir seal integrity and storage capacity, including CO2 injection efficiency. Formation of solid hydrates in the near-wellbore area during CO2 injection can cause permeability impairment and, eventually, injectivity loss. In this study, flow remediation in hydrate-plugged sandstone was assessed as function of hydrate morphology and saturation. CO2 and CH4 hydrates formed consistently at elevated pressures and low temperatures, reflecting gas-invaded zones containing residual brine near the injection well. Flow remediation by methanol injection benefited from miscibility with water; the methanol solution contacted and dissociated CO2 hydrates via liquid water channels. Injection of N2 gas did not result in flow remediation of non-porous CO2 and CH4 hydrates, likely due to insufficient gas permeability. In contrast, N2 as a thermodynamic inhibitor dissociated porous CH4 hydrates at lower hydrate saturations (<0.48... [more]

All Carbon Capture and Storage (CCS) projects require the transportation of CO2 from a source to a storage location. Although, a compressor and a large diameter pipeline is the normal method used to achieve this, liquefaction, shipping and pumping is sometimes attractive. Identifying the economic optimum is important for all CCS projects, minimizing energy consumption is also important because it corresponds to a resource efficiency in fossil-fuel based projects. This article describes the development and validation of a model that estimates the energy consumption associate with CO2 transportation using the geographic location of the source and the reservoir to incorporate ambient temperature and bathymetry data. The results of the validation work show an average absolute temperature and pressure error less than 1 °C and 1 bar compared to a reference model. The model has been developed using openly accessible data and is made available in a repository for open research data.

The paper presents an analysis of the possible location of geological formations suitable for CO2 storage in the Upper Silesia Coal Basin, Poland. The range of the reservoir has been determined on the basis of an analysis of basic geological parameters, which determine the selection criteria for sites suitable for CO2 storage. A dynamic modelling of the CO2 distribution in the aquifer is presented. Based on the constructed model of migration, reactivity, and geochemical transport of CO2 in geological structures, it is possible to identify potential migration routes and escape sites of CO2 on the surface. The analysis of the technical and geological possibilities of CO2 storage was carried out according to the regulations of the complex Polish geological law, specifically in terms of sequestration possibilities in geological formations.

The effect of supercritical CO2 on the shaly caprocks is one of the critical issues to be considered in CO2 sequestration programs. Shale-scCO2 interactions can alter the seal integrity, leading to environmental problems and bringing into question the effectiveness of the program altogether. Several analytical studies were conducted on samples from Jurassic Eneabba Basal Shale and claystone rich facies of the Triassic Yalgorup Member (725−1417 m) in the Harvey CO2 sequestration site, Western Australia, to address the shale-scCO2 interactions and their effect on the petrophysical properties of the caprock. Shale samples saturated with NaCl brine were exposed to scCO2 under the reservoir condition (T = 60 °C, P = 2000 psi) for nine months and then tested to determine their altered mineralogical, petrophysical and geochemical properties. The experimental study examined changes to the mineralogical composition, capillary threshold pressure, and pore size distribution (PSD) of samples. The... [more]

Shale oil and gas resources contribute significantly to the energy production in the U.S. Greenhouse gas emissions come from combustion of fossil fuels from potential sources of power plants, oil refineries, and flaring or venting of produced gas (primarily methane) in oilfields. Economic utilization of greenhouse gases in shale reservoirs not only increases oil or gas recovery, but also contributes to CO2 sequestration. In this paper, the feasibility and efficiency of gas injection approaches, including huff-n-puff injection and gas flooding in shale oil/gas/condensate reservoirs are discussed based on the results of in-situ pilots, and experimental and simulation studies. In each section, one type of shale reservoir is discussed, with the following aspects covered: (1) Experimental and simulation results for different gas injection approaches; (2) mechanisms of different gas injection approaches; and (3) field pilots for gas injection enhanced oil recovery (EOR) and enhanced gas reco... [more]