Interaction of Regulatory Aspects for Carbon Capture and Utilization Applications

Carbon capture and utilization (CCU) technologies can lead to a net reduction of CO₂ emissions but also to a transfer from emissions between different regulatory areas. This paper presents a tool to evaluate the impact of CCU technology within the European regulatory framework with respect to the accounting of carbon transferred between the CO₂ source and its subsequent application. Additional emissions caused by energy requirements of the capture or any conversion steps are not considered. The tool is applied to a variety of possible combinations and their respective impact evaluated.     

High Temperature Co-Electrolysis as a Key Technology for CO2 Emission Mitigation – A Model-Based Assessment of CDA and CCU

The mitigation of CO₂ emissions is a major challenge for modern society. While the mitigation of energy-related emissions can be achieved comparatively easy by switching to renewable energy sources, reduction of process-related industrial emissions is considerably more challenging. To reduce industrial CO₂ emissions, two basic routes are available: carbon direct avoidance (CDA) and carbon capture and utilization (CCU). It is shown that in terms of efficiency, CDA is to be favored when applicable. However, for applications where emissions cannot be avoided, CCU can be a viable approach allowing for emission mitigation.     

Optimization-based identification of CO2 capture and utilization processing paths for life cycle greenhouse gas reduction and economic benefits

This paper introduces a mathematical formulation to identify promising CO₂ capture and utilization (CCU) processing paths and assess their production rates by solving an optimization problem. The problem is cast as a multi-objective one by simultaneously maximizing a net profit and life cycle greenhouse gas (GHG) reduction. Three case studies are illustrated using an exemplary CCU processing network. The results indicate the optimal solution is greatly influenced by the scale of CO₂ emission source, market demand, and hydrogen availability. Moreover, with the current system of measuring the GHG reduction regarding a business-as-usual level, if the aim is to achieve a GHG reduction within a national boundary, the question of whether CCU plants producing a product of same functionality through conventional means, which the CO₂-based product can replace, exists in the country can come into consideration. This systematic identification will assist decision-making regarding future R&D investment and construction of large-scale CCU plants.     

Optimal European cooperative supply chains for carbon capture,transport, and sequestration with costs share policies

In the past decades, CO₂ constituted nearly the 80% of anthropogenic greenhouse gases emissions therefore, global actions are needed to tackle the increase of carbon concentration in the atmosphere. CO₂ (carbon) capture and storage has been highlighted among the most promising options to decarbonize the energy and industry sectors. Considering a large-scale infrastructure at European level, economic cooperation has been highlighted as a key requirement to relieve single countries from too high risk and commitment. This article proposes an economic optimization for cooperative supply chains for CO₂ capture and storage, by adopting policies that balance the spread of costs among countries, according to local characteristics in terms of population, CO₂ emissions, and macroeconomic outcome. Results show that the additional European investment for cooperation (max. +2.6% with respect to a noncooperative network) should not constitute a barrier toward the installation and operation of such more effective network designs.     

CO2 utilization for methanol production; Optimal pathways with minimum GHG reduction cost

Mitigating CO₂ emissions from industries and other sectors of our economy is a critical component of building a sustainable economy. This paper investigates two different methanol synthesis routes based on CO₂ utilization (CO₂ capture and utilization [CCU], and tri-reforming of methane [TRM]), and compares the results with the conventional methanol production using natural gas as the feedstock (NG-MeOH). A comprehensive techno-economic analysis (TEA) model that includes the findings of the life cycle assessment (LCA) models of methanol production using various CO₂ utilization pathways is conducted. Economic analysis is conducted by developing a cost model that is connected to the simulation models for each production route. Compared to the conventional process (with a GHG emission of 0.6 kg CO₂/kg MeOH), the lifecycle GHG reduction of 1.75 and 0.41 kg CO₂/kg MeOH are achievable in the CCU and TRM pathways, respectively. Furthermore, the results indicate that, under current market conditions and hydrogen production costs, methanol production via CO₂ hydrogenation will result in a cost approximately three times higher than that of the conventional process. The integrated TEA–LCA model shows that this increased cost of production equates to a required life cycle GHG reduction credit of $279 to $422 per tonne of CO₂ utilized, depending on construction material and selected pathway. Additionally, when compared to the CO₂ hydrogenation route, the tri-reforming process (TRM-MeOH) can result in a 42% cost savings. Furthermore, a minimum financial support of $56 per tonne utilized CO₂ will be required to make the TRM-MeOH process economically viable.     

Shortcut Evaluation of Chemical Carbon Dioxide Utilization Processes

Chemical utilization of carbon dioxide seems to be an attractive option for the mitigation of greenhouse gas emissions. However, the respective processes themselves cause substantial greenhouse gas emissions. To achieve a good CO₂ balance, it is necessary not only to fix carbon but also to do this efficiently in terms of reactant supply and energy demand. An evaluation of the CO₂ balance requires detailed process simulation for the utilization reaction and the supply chain. To allow a quick evaluation of the potential to mitigate emissions, a number of estimation methods are presented.     

Carbon capture from stationary power generation sources: A review of the current status of the technologies

The world will need greatly increased energy supply in the future for sustained economic growth, but the related CO₂ emissions and the resulting climate changes are becoming major concerns. CO₂ is one of the most important greenhouse gases that is said to be responsible for approximately 60% of the global warming. Along with improvement of energy efficiency and increased use of renewable energy sources, carbon capture and sequestration (CCS) is expected to play a major role in curbing the greenhouse gas emissions on a global scale. This article reviews the various options and technologies for CO₂ capture, specifically for stationary power generation sources. Many options exist for carbon dioxide capture from such sources, which vary with power plant types, and include post-combustion capture, pre-combustion capture, oxy fuel combustion capture, and chemical looping combustion capture. Various carbon dioxide separation technologies can be utilized with these options, such as chemical absorption, physical absorption, adsorption, and membrane separation. Most of these capture technologies are still at early stages of development. Recent progress and remaining challenges for the various CO₂ capture options and technologies are reviewed in terms of capacity, selectivity, stability, energy requirements, etc. Hybrid and modified systems hold huge future potentials, but significant progress is required in materials synthesis and stability, and implementations of these systems on demonstration plants are needed. Improvements and progress made through applications of process systems engineering concepts and tools are highlighted and current gaps in the knowledge are also mentioned. Finally, some recommendations are made for future research directions.     

Assessment of Industrial Greenhouse Gas Reduction Strategies Within Consistent System Boundaries

With respect to the climate goals of the greenhouse gas (GHG) neutrality in 2050, different GHG reduction strategies are discussed for industrial processes. For a comparison of the strategies carbon direct avoidance (CDA), carbon capture and storage, and carbon capture and utilization (CCU), the method system expansion is applied. Exemplarily, the CO₂ reduction potential and the energy demand are determined. The Carbon2Chem® project is described as an example of CCU for the steel and chemical production. The direct reduction with H₂ represents the CDA strategy for the steel industry.     

Comparative study of coal,natural gas,and coke-oven gas based methanol to olefins processes in China

Traditional olefins production mainly depends on oil. In view of the short supply of oil, feedstocks are expanded to coal, natural gas, coke-oven gas, and methanol in China. In this paper, a comparative study of alternative olefins production is conducted from aspects of techno-economic feasibility and environmental friendliness. Results show that coal-to-olefins has a significant cost advantage. However, it suffers from low energy efficiency and serious CO₂ emissions. To address these problems, this study proposes and analyses coal-to-olefins with CO₂ capture, coal and natural gas-to-olefins, and coal and coke-oven gas-to-olefins. The two co-feed systems ensure great reduction of CO₂ emissions and significant improving energy efficiency. They should be actively developed in regions with rich coal and gas. While in regions with rich coal and lean gas, coal-to-olefins with CO₂ capture should be developed in large scale. This paper also provides several suggestions on planning these olefins production routes in China.     

Mathematical modelling of sustainable wastewater reuse networks considering CO<Subscript>2</Subscript> emissions

Water resource management poses a challenge in the process industry because a large amount of water must be used, even when prices increase. Companies struggle to minimize consumption by reusing wastewater, and the resulting water-reuse-network problem has been actively investigated. With the rising impact of global climate change, it is necessary to develop a sustainable methodology to reduce carbon dioxide emissions in the process industry. This paper proposes a mathematical model for sustainable water reuse networks that explicitly considers CO₂ emissions. To construct a sustainable network, emissions due to the construction and operation of the water network and additional water demand due to CO₂ capture facilities are incorporated. Actual case studies of steel manufacturing processes and eco-industrial parks are presented to illustrate the applicability of the model.     

Combined Decarbonization of Electrical Energy Generation and Production of Synthetic Fuels by Renewable Energies and Fossil Fuels

Power generation from renewable energy sources and fossil fuels are integrated into one system. A combination of technologies in the form of a carbon capture utilization (CCU)-combined power station is proposed. The technology is based on energy generation from fossil fuels by a coal power plant with CO₂ recovery from exhaust gases, and pyrolysis of natural gas to hydrogen and carbon, completed by reverse water-gas shift for the conversion of CO₂ to CO, which will react with hydrogen in a Fischer-Tropsch synthesis for synthetic diesel. The carbon from the pyrolysis can replace other fossil carbon or can be sequestered. This technology offers significant CO₂ savings compared to the current state of technology and makes an environmentally friendly use of fossil fuels for electricity and fuel sectors possible.     

Reduction of Greenhouse Gas Emissions from Gas,Oil, and Coal Power Plants in Pakistan by Carbon Capture and Storage (CCS): A Review

The production of energy in Pakistan as a developing country mainly depends on consumption of fossil fuels, which are the main sources of greenhouse gas (GHG) emissions. These emissions can be mitigated by implementing carbon capture and storage (CCS) in running plants. An overview of the current and future potentials of Pakistan for CCS is provided, indicating a great potential for this technology to capture CO₂ emissions. The amine CO₂ capture process as the most mature procedure is currently applied in many oil and gas companies in Pakistan, which can be employed to capture CO₂ from other industries as well. Pakistan has a great CO₂ storage potential in oil, gas, and coal fields and in saline aquifer as well as significant resources of Mg and Ca silicates suitable as feedstock in the carbon mineralization process. For further development and implementation of CCS technologies in Pakistan, economic and policy barriers as the main obstacles should be alleviated.     

Experimental investigation of a circulating fluidized‐bed reactor to capture CO2 with CaO

Calcium looping processes for capturing CO₂ from large emissions sources are based on the use of CaO particles as sorbent in circulating fluidized‐bed (CFB) reactors. A continuous flow of CaO from an oxyfired calciner is fed into the carbonator and a certain inventory of active CaO is expected to capture the CO₂ in the flue gas. The circulation rate and the inventory of CaO determine the CO₂ capture efficiency. Other parameters such as the average carrying capacity of the CaO circulating particles, the temperature, and the gas velocity must be taken into account. To investigate the effect of these variables on CO₂ capture efficiency, we used a 6.5 m height CFB carbonator connected to a twin CFB calciner. Many stationary operating states were achieved using different operating conditions. The trends of CO₂ capture efficiency measured are compared with those from a simple reactor model. This information may contribute to the future scaling up of the technology. © 2010 American Institute of Chemical Engineers AIChE J, 57: 000–000, 2011     

Application of a Waste Carbon Material as the Carbonaceous Reductant During Silicon Production

It is important to study the application of alternative carbon reductants for industrial silicon smelting to reduce consumption of carbonaceous reducing agents, electricity, and CO₂ emissions during silicon production. In this study, an industrial experiment was carried out in an 8 MVA submerged arc furnace using waste carbon material in place of approximately 20% partial reducing agents. The system was analyzed for silicon yield, power consumption, overall energy efficiency, CO₂ emissions, and the utilization rate of carbonaceous materials. The system improved the efficiency of carbonaceous materials and decreased power consumption using alternative carbon reductants. The results have showed that use of waste carbon materials reduced carbon emissions per ton silicon by more than 19.14% and specific CO₂ emissions decreased to 0.865 t.     

Recent advances on the membrane processes for CO2 separation

Membrane separation technology has popularized rapidly and attracts much interest in gas industry as a promising sort of newly chemical separation unit operation. In this paper, recent advances on membrane processes for CO₂ separation are reviewed. The researches indicate that the optimization of operating process designs could improve the separation performance, reduce the energy consumption and decrease the cost of membrane separation systems. With the improvement of membrane materials recently, membrane processes are beginning to be competitive enough for CO₂ separation, especially for post-combustion CO₂ capture, biogas upgrading and natural gas carbon dioxide removal, compared with the traditional separation methods. We summarize the needs and most promising research directions for membrane processes for CO₂ separation in current and future membrane applications. As the time goes by, novel membrane materials developed according to the requirement proposed by process optimization with increased selectivity and/or permeance will accelerate the industrialization of membrane process in the near future. Based on the data collected in a pilot scale test, more effort could be made on the optimization of membrane separation processes. This work would open up a new horizon for CO₂ separation/Capture on Carbon Capture Utilization and Storage (CCUS).     

An overview of the Department of Energy's CarbonSAFE Initiative: Moving CCUS toward commercialization

The U.S. Department of Energy (DOE) Office of Fossil Energy (FE) National Energy Technology Laboratory (NETL) Carbon Storage Program helps develop technologies that safely and permanently store carbon dioxide (CO₂) without adversely impacting natural resources or hindering economic growth. Since 1997, the program has significantly advanced carbon capture, utilization, and storage (CCUS) science and technology, with more than 10.5 million metric tons (MMT) of CO₂ safely stored. However, key gaps in experience and knowledge remain (e.g., the technology, expertise, and processes needed to safely characterize and monitor 50+ MMT-scale geologic CO₂ storage sites). DOE's Carbon Storage Assurance Facility Enterprise (CarbonSAFE) Initiative (launched in FY16) is beginning to address this gap. The CarbonSAFE Initiative currently consists of 13 projects in Phase I: Integrated Carbon Capture and Storage (CCS) Pre-Feasibility and six projects in Phase II: Storage Complex Feasibility. This article includes the latest updates from the CarbonSAFE Initiative.     

CO2 utilization in Eastern Canada: Sources,sites, and grid effects

Achieving net zero carbon dioxide (CO₂) emissions will require the cessation of fossil fuel emissions into the atmosphere, yet the need for ‘fuel’ and energy storage will remain. One solution could be a carbon-based fuel system where CO₂ of biogenic origin is converted to fuels using hydrogen generated by electrolysis powered by renewable energy sources. Methane has value as an initial target given its prevalence in biogas, use in home heating and in electricity generation. Sources of CO₂ in Eastern Canada are dominated by the iron and steel, cement, and aluminium industries, all of which have biogenic fuel options. Collecting all of the potentially biogenic CO₂ would displace 75% of current natural gas use and require a 50% increase in generating capacity. Initial efforts could site a carbon capture, utilization, and storage facility near Montreal, QC, with other large-scale facilities near Hamilton, ON, and Lac St-Jean, QC. These facilities would be grid connected and expected to operate ~6200 h annually. The most high-frequency electrolysis events would be 10 h of run time and 2 h of idle time. These periods would peak during the equinox months and be at a minimum during the winter solstice. These operational assumptions will all be subject to the increased variability caused by anthropogenic climate change and increased renewable generation on the grid. A closed-loop carbon-based fuel system would require an equivalent price of $250 per tonne CO₂.     

Chemical functionalization strategies for carbon dioxide capture in microporous organic polymers

We review the design and use of microporous polymers for pre‐ and post‐combustion capture of CO₂. Microporous organic polymers are promising candidates for CO₂ capture materials. They have good physicochemical stabilities and high surface areas. Ultrahigh‐surface‐area microporous organic polymers could find use in pre‐combustion capture, while networks with lower surface areas but higher heats of sorption for CO₂ might be more relevant for lower pressure, post‐combustion capture. We discuss strategies for enhancing CO₂ uptakes including increasing surface area, chemical functionalization to provide high‐enthalpy binding sites and the potential for pore size tuning. © 2013 Society of Chemical Industry     

Recent progress of amine modified sorbents for capturing CO2 from flue gas

Under the Paris agreement, China has committed to reducing CO₂ emissions by 60%–65% per unit of GDP by 2030. Since CO₂ emissions from coal-fired power plants currently account for over 30% of the total carbon emissions in China, it will be necessary to mitigate at least some of these emissions to achieve this goal. Studies by the International Energy Agency (IEA) indicate CCS technology has the potential to contribute 14% of global emission reductions, followed by 40% of higher energy efficiency and 35% of renewable energy, which is considered as the most promising technology to significantly reduce carbon emissions for current coal-fired power plants. Moreover, the announcement of a Chinese national carbon trading market in late 2017 signals an opportunity for the commercial deployment of CO₂ capture technologies.Currently, the only commercially demonstrated technology for post-combustion CO₂ capture technology from power plants is solvent-based absorption. While commercially viable, the costs of deploying this technology are high. This has motivated efforts to develop more affordable alternatives, including advanced solvents, membranes, and sorbent capture systems. Of these approaches, advanced solvents have received the most attention in terms of research and demonstration. In contrast, sorbent capture technology has less attention, despite its potential for much lower energy consumption due to the absence of water in the sorbent. This paper reviews recent progress in the development of sorbent materials modified by amine functionalities with an emphasis on material characterization methods and the effects of operating conditions on performance. The main problems and challenges that need to be overcome to improve the competitiveness of sorbent-based capture technologies are discussed.     

Burning and cultivation effects on greenhouse gas emissions and nutrients in wetland soils from Saskatchewan,Canada

Wetland fringe areas in prairie agricultural landscapes may be subjected to burning of vegetation in autumn followed by cultivation in spring. The objective of this study was to examine the greenhouse gas (CO₂, N₂O and CH₄) emissions and plant nutrient (NO₃, PO₄ and SO₄) supplies in wetland fringe soils as affected by simulated burning + cultivation, at field capacity and saturation moisture content. Using undisturbed soil cores collected from grassed wetland fringes at four sites in southern Saskatchewan, the impacts were examined over a 20-day period. The burning + cultivation treatment generally reduced CO₂ emissions, tended to increase NO₃–N availability, and had no consistent effect on N₂O emissions, or PO₄–P and SO₄–S supply. Production of CH₄ occurred only at one site, and only under saturated conditions. Compared to field capacity, saturation reduced CO₂ emissions and NO₃–N supply, tended to increase PO₄–P availability, and had no consistent effect on N₂O emissions and SO₄–S. The CO₂ emissions and SO₄–S were greater for soil cores with higher organic matter and salinity, respectively. The N₂O emissions were only occasionally related to soil NO₃–N supply rate.