Global warming and climate change concerns have triggered global efforts to reduce the concentration of atmospheric carbon dioxide (CO2). Carbon dioxide capture and storage (CCS) is considered a crucial strategy for meeting CO2 emission reduction targets. In this paper, various aspects of CCS are reviewed and discussed including the state of the art technologies for CO2 capture, separation, transport, storage, leakage, monitoring, and life cycle analysis. The selection of specific CO2 capture technology heavily depends on the type of CO2 generating plant and fuel used. Among those CO2 separation processes, absorption is the most mature and commonly adopted due to its higher efficiency and lower cost. Pipeline is considered to be the most viable solution for large volume of CO2 transport. Among those geological formations for CO2 storage, enhanced oil recovery is mature and has been practiced for many years but its economical viability for anthropogenic sources needs to be demonstrated. There are growing interests in CO2 storage in saline aquifers due to their enormous potential storage capacity and several projects are in the pipeline for demonstration of its viability. There are multiple hurdles to CCS deployment including the absence of a clear business case for CCS investment and the absence of robust economic incentives to support the additional high capital and operating costs of the whole CCS process.

https://www.elsevier.com/__data/assets/pdf_file/0005/96980/Current-status-carbon-capture.pdf

An overview of current status of carbon dioxide capture and storage technologies

Carbon capture and storage (CCS) is broadly recognised as having the potential to play a key role in meeting climate change targets, delivering low carbon heat and power, decarbonising industry and, more recently, its ability to facilitate the net removal of CO2 from the atmosphere. However, despite this broad consensus and its technical maturity, CCS has not yet been deployed on a scale commensurate with the ambitions articulated a decade ago. Thus, in this paper we review the current state-of-the-art of CO2 capture, transport, utilisation and storage from a multi-scale perspective, moving from the global to molecular scales. In light of the COP21 commitments to limit warming to less than 2 °C, we extend the remit of this study to include the key negative emissions technologies (NETs) of bioenergy with CCS (BECCS), and direct air capture (DAC). Cognisant of the non-technical barriers to deploying CCS, we reflect on recent experience from the UK's CCS commercialisation programme and consider the commercial and political barriers to the large-scale deployment of CCS. In all areas, we focus on identifying and clearly articulating the key research challenges that could usefully be addressed in the coming decade.

/pdf/carbon-capture-and-storage-ccs-the-way-forward-11rgsqyer0.pdf

Carbon capture and storage (CCS): the way forward

In recent years, Carbon Capture and Storage (Sequestration) (CCS) has been proposed as a potential method to allow the continued use of fossil-fuelled power stations whilst preventing emissions of CO2 from reaching the atmosphere. Gas, coal (and biomass)-fired power stations can respond to changes in demand more readily than many other sources of electricity production, hence the importance of retaining them as an option in the energy mix. Here, we review the leading CO2 capture technologies, available in the short and long term, and their technological maturity, before discussing CO2 transport and storage. Current pilot plants and demonstrations are highlighted, as is the importance of optimising the CCS system as a whole. Other topics briefly discussed include the viability of both the capture of CO2 from the air and CO2 reutilisation as climate change mitigation strategies. Finally, we discuss the economic and legal aspects of CCS.

Carbon capture and storage update

https://www.wto.org/english/tratop_e/envir_e/wksp_envir_nov12_e/3floriankern_sprusussexuniversity_e.pdf

Carbon Capture and Storage

While Carbon Capture and Storage (CCS) technologies are being developed with the focus of capturing and storing CO2 in huge quantities, new methods for the chemical exploitation of carbon dioxide (CCU) are being developed in parallel. The intensified chemical or physical utilization of CO2 is targeted at generating value from a limited part of the CO2 stream and developing better and more efficient chemical processes with reduced CO2 footprint. Here, we compare the status of the three main lines of CCS technologies with respect to efficiency, energy consumption, and technical feasibility as well as the implications of CCS on the efficiency and structure of the energy supply chain.

/pdf/worldwide-innovations-in-the-development-of-carbon-capture-5311omzkbj.pdf

Worldwide innovations in the development of carbon capture technologies and the utilization of CO2

Dynamis CO2 quality recommendations

Increased focus on reducing CO2 emissions has created growing interest in CO2 capturing from industrial processes for storage in geologic formations or injection in oil reservoirs for enhanced oil recovery (EOR). Due to the scattered CO2 sources and the uncertainty in the growth of the CO2 market, a cost effective and flexible transport system is required. In this work a ship transport concept is developed as an alternative to pipeline transport. New technical solutions, cost-, energy-, exergy- and CO2 emission analysis for ship-based transport of CO2 are presented. The concept includes all the elements in the transport chain, namely liquefaction, intermediate storage, loading system, semi-pressurized ship and offshore unloading system. Economical large-scale transport of CO2 by ship could be done in semi-pressurized vessels of around 20 000 m3 at pressures near triple point (6.5 bara and –52°C) in order to use well established design for commercial construction of LPG carriers and intermediate storage. This condition also gives the highest density in the liquid state, which reduces the transport unit cost. Liquefaction of CO2 is best achieved in an open cycle, where the refrigeration is partly or fully provided by the feed gas itself. The offshore unloading system will transport the liquid CO2 from the dedicated CO2 ship to the wellhead on the platform at the required temperature and pressure. During the unloading phase the ship is connected to a submerged turret loading (STL) system. The CO2 is pumped to a pressure high enough to avoid phase transition in the transfer lines. A flexible riser, a subsea pipeline and an insulated pipeline in the platform shaft bring the CO2 from the unloading location to the topside of the platform. The CO2 is pumped to injection pressure and heated to avoid operational problems before it is injected into the reservoir for EOR using conventional water injection wells. The total specific energy requirement for the selected transport chain is 142 kWh tonne−1 CO2, where the liquefaction process accounts for 77%. An exergy analysis of the chain is performed showing that the minimum work required in the chain is 60 kWh tonne−1 CO2, giving a chain rational efficiency of 42%. The total CO2 emissions are estimated to be approximately 1.4% of the inlet CO2. The total costs of ship-based transport are calculated to be 20–30 USD tonne−1 for volumes larger than 2 Mt y−1 and distances limited to the North Sea. Ship transport offers a flexible alternative for bringing CO2 to offshore installations. Dedicated CO2 carriers for transport of CO2 directly from the source to the oil fields might be a key element in future CO2 infrastructures.

Ship Transport of CO2: Technical Solutions and Analysis of Costs, Energy Utilization, Exergy Efficiency and CO2 Emissions

Hydrogen quality from decarbonized fossil fuels to fuel cells

One of the measures for reducing global CO2 emissions is to capture CO2 and store it safely in geological formations. Safe and effective CO2 management requires reliable tools for calculate accurately the properties of both pure CO2 and CO2 in mixtures. If the default models and parameters of commercial flow sheeting tools are used when predicting the solubility of water in CO2 and CO2 in mixtures may not always result in satisfactory results. Having in mind the need for reliable operation of the processes along the CO2 capture, transport and injection chain, reliable tools are cardinal. The purpose of the present work has been to establish reliable model parameters by selecting equation of state (EOS) models for evaluation, develop a database of reliable experimental data on solubility of H2O, CO2 and CH4 based on data collected from literature, use the data to establish and suggest model parameters based on the database, and test and document the ability of the various EOS models to predict the solubility of H2O in CO2 or a mixture of CO2 and CH4. Experimental data on solubility of H2O, CO2 and CH4 were collected from literature and compared with a model based on the rest of the experimental data in order to evaluate the quality of the data. The second order SRK-HV (SRK-Huron Vidal) model with six parameters was used as model for evaluating the experimental data. The models SRK-VdW (Soave Redlich Kwong, Van der Waals mixing rules), SRK-HV (SRK-Huron Vidal) and the CPA (Cubic Plus Association) was evaluated. Based on the data for the mutual solubilities of H2O, CO2 and CH4, new model parameters were adapted for the SRK-HV, and the CPA models. Solubility of H2O in CO2 and H2O in the CO2–CH4 mixture was emphasized. The second order SRK-HV model produced acceptable results with deviation from 3% to 9% between experiments and the model. The CPA model was less accurate, producing results with deviation from 9% to 35% between experiments and the model. The SRK-VdW model gave two different binary coefficients, one for solubility of water in liquid CO2 and another for solubility of CO2 in water. That gave same deviation as the SRK-HV model, (typically 7% for H2O in CO2 but 93% for CO2 in water, or 4% for CO2 in water but 390% for H2O in CO2 with another binary coefficient). The SRK-VdW is not indented for use of two different binary coefficients.

Mona J. Mølnvik

Papers

Dynamis CO2 quality recommendations

Ship Transport of CO2: Technical Solutions and Analysis of Costs, Energy Utilization, Exergy Efficiency and CO2 Emissions

Hydrogen quality from decarbonized fossil fuels to fuel cells

Thermodynamic Models for Calculating Mutual Solubilities in H2O–CO2–CH4 Mixtures

Optimization of a simple LNG process using sequential quadratic programming