CO2 Pipeline Transport Research Articles

Analysis of GHG Emission Reduction in South Korea Using a CO2 Transportation Network Optimization Model

Korea’s national carbon capture and storage (CCS) master plan aims to commercialize CCS projects by 2030. Furthermore, the Korean government is forced to reduce emissions from various sectors, including industries and power generation, by 219 million tons by 2030. This study analyzes a few scenarios of Korean CCS projects with a CO2 pipeline transportation network optimization model for minimizing the total facility cost and pipeline cost. Our scenarios are based on the “2030 basic roadmap for reducing greenhouse gases” established by the government. The results for each scenario demonstrate that the effective design and implementation of CO2 pipeline network enables the lowering of CO2 units cost. These suggest that CO2 transportation networks, which connect the capture and sequestration parts, will be more important in the future and can be used to substitute and supplement the emission reduction target in case the execution of other reduction options faces uncertainty. Our mathematical model and scenario designs will be helpful for various countries which plan to introduce CCS technology.

Implications of the New EU Maritime Emission Monitoring Regulation on Ship Transportation of CO2

In the framework of the CCSP R&D program, the regulatory gaps have been assessed at VTT using the current monitoring rules for capture, pipeline transportation and geological storage of CO2 as a benchmark. The scope of the presented work includes: (i) definition of CO2 emissions from ship transportation of CO2; (ii) review of EU regulations on MRV of maritime CO2 emissions; and (iii) review of the MRV regulation on capture, transport and geological storage of CO2 under the EU-ETS. The considered activities related to ship transportation of CO2 are liquefaction and intermediate storage with recirculation loop for boil-off CO2, loading and unloading facilities and CO2 transportation and handling during the ship voyage.Identification of the regulatory gaps, based on the above, shows what is needed to enable ship transportation of CO2 for geological storage in Europe. Based on the results, maritime transportation for CCS could be made possible with very limited new emission monitoring and verification practices. Also the trade-offs of using an MRV regulation analogous to pipeline transportation of CO2 is discussed in the results.

Towards a thorough Validation of Simulation Tools for CO2 Pipeline Transport

In this work the Schlumberger flow assurance tool OLGA and SINTEF Energy Research in-house CFD tool are assessed for their ability to describe depressurization behaviour of CO2 pipelines. For this purpose, three full-bore experimental depressurization tests with pure CO2 have been performed at the Statoil's R&D center in Trondheim, Norway.Simulations results are in general agreement with the experiments with the exception of the behaviour at the innermost position of the where OLGA predicts significantly lower temperatures, and SINTEF tool over-estimate the temperature. Both models predict liquid dry-out time with an error of a few seconds.The simulation results are sensitive to the pipe outer heat transfer coefficient, used between the pipe surface and the ambient humid air. Reduction of the uncertainty in the heat-flux to the pipe is identified as a key factor for further validation.

A fracture-propagation-control model for pipelines transporting [formula omitted]-rich mixtures including a new method for material-model calibration

This work considers a predictive numerical modelling approach for fracture-propagation control in CO2-transport pipelines, an area where current engineering tools do not work. Fluid–structure interaction model simulations are compared with three published medium-scale crack-arrest experiments with CO2-rich mixtures. The fluid flow is calculated by a one-dimensional homogeneous equilibrium model, and the thermodynamic properties of CO2 are modelled using the Span–Wagner and the Peng–Robinson equation of state. The pipe material is represented by a finite-element model taking into account large deformations and fracture propagation. Material data commonly found in the literature for steel pipes in crack-arrest experiments is not sufficient to directly calibrate the material model used here. A novel three-step calibration procedure is proposed to fill the information gap in the material data. The resulting material model is based on J2 plasticity and a phenomenological ductile fracture criterion. It is shown that the numerical model provides good predictions of the pressure along the pipe, the ductile fracture speed and a conservative estimate of the final crack length. An approximately plane-strain stress state ahead of crack tip implies that a fracture criterion accounting for a wide range of stress states is not necessary.

Correlative comparison of gas CO2 pipeline transportation and natural gas pipeline transportation

Correlative comparison of gas CO2 pipeline transportation and natural gas pipeline transportation

Effects of Impurities on CO2 Pipeline Performance

Carbon dioxide (CO2) is a chief constituent of greenhouse gases and should be captured, transported and stored in saline aquifers or used for enhanced oil recovery. This study is focused on pipeline transportation of impure CO2. The major impurities in captured CO2 from power plant stations and gas processing facilities are mainly nitrogen, methane, hydrogen sulphide, and water. Impurities affect the density and viscosity of the CO2 stream thereby impacting on the fluid phase, pressure and temperature of the stream. CO2 pipeline models, however, rarely consider the effects of impurities in the determination of design parameters. Aspen HYSYS (ver.9) is used to model the effect of impurities on the pressure drop, phase envelope and critical pressure and temperature of captured CO2 fluids flowing in pipelines. Cortez, Canyon Reef and Choctaw pipelines in the USA and Weyburn pipeline in Canada were selected as the case studies. The results show that the pressure drop increased in these pipelines due to the impurities with the highest pressure drop occurring in the Canyon Reef pipeline. The impurities increased the pressure drop by about 0.09 bar/km, 0.2 bar/km, 0.10 bar/km and 0.04 bar/km for Cortez, Canyon Reef, Choctaw and Weyburn pipelines respectively. The lower molecular weight gases were found to decrease the mixture density and increase the pressure drop. The results also reveal that the bubble point pressure was increased by impurities in three pipelines but slightly reduced in the Weyburn pipeline and the critical temperature was reduced in all pipelines.

Robust and stepwise optimization design for CO2 pipeline transportation

Carbon capture, utilization, storage (CCUS) technology is an effective means to reduce the CO2 emissions. It has been noted that engineering and economic design of the pipeline transportation are important components for CCUS. However, the uncertainties of the pipeline transportation model may make an infeasible design in practice and cause unnecessary cost. In this paper, a novel robust optimization method is proposed for CO2 pipeline transportation design, which can deal with the multiple uncertainties. A stepwise method is presented to further improve the optimization performance. The proposed optimal algorithm is validated by using numerical studies, which shows that the proposed approach can deal with the multiple uncertainties and improve the design performance in comparison with the existing

Research on CO2Quality Pipeline Transportation Based on Yanchang Oilfield CCUS

CO 2 capture,utilization and storage (CCUS) is now recognized as an important technology in the global scope of CO 2 emission reduction, pipeline transportation is the main center to connect the capture point and the use storage point, the first issue to CO2 pipeline transportation is to solve CO 2 source quality research. Yanchang Oilfield has the advantages of CCUS, its coal chemical capture of CO 2 contains different impurities. In the CO 2 pipeline transportation, the impurity content in CO 2 is based on its end use and the actual situation of pipeline. The impurities will affect the efficiency of CO 2 -EOR, the choice of CO 2 state equation, the changes of CO 2 phase diagram and the capacity of pipeline transportation.

Flow measurement of CO2 in a binary gaseous mixture using an averaging Pitot Tube and Coriolis mass flowmeters

To combat the growing emissions of CO2 from industrial processes, Carbon Capture and Storage (CCS) and Carbon Capture and Utilization technologies (CCU) have been accepted worldwide to address these pressing concerns. So as to efficiently manage material and financial losses across the entire stream, accurate accounting and monitoring through fiscal metering of CO2 in CCS transportation pipelines are core and required features for the CCS technologies. Moreover, these technical requirements are part of the legal compliance schemes and guidelines from various regulatory bodies. The CO2 transportation pipelines will likely have multiple inputs from different capture plants, each with varying composition of CO2 and thus introducing impurities into the CO2 stream. The presence of other ordinary or hydrocarbon gases in the CO2 gas stream could affect the functionality of metering instruments by introducing additional errors, particularly in the case of volumetric flowmeters. In this study, volumetric and direct mass measurement methods for the flow measurement of CO2 mixtures using two totally different metering principles are experimentally evaluated. An Averaging Pitot Tube with Flow Conditioning Wing (APT-FCW) and Coriolis mass flowmeters (CMF) are used to assess the flow metering of CO2 in a binary gaseous mixture. Different gases (nitrogen, air, oxygen, argon and propane) are diluted as contaminants into the pure CO2 gas flow for various mass fractions to produce an adulterated mixture of the CO2 gas. Comparative analysis of the measurement results under these flow conditions relative to that of pure CO2 gas show that the measurement error of the APT-FCW sensor increases with the mass fraction of the diluent component, and gases with density closer to that of CO2 have a much lesser effect on the performance of the APT-FCW flow sensor for smaller mass fractions. The CMF proved to be very reliable in the gas combination processes and as a reference meter for the APT-FCW sensor. Further analytical observations are discussed in detail.

Impact of stream impurities on compressor power requirements for CO2 pipeline transportation

The economic viability of Carbon Capture and Sequestration (CCS) as a means of mitigating CO2 emissions is significantly dependent on the minimisation of costs associated with the compression and transportation of the captured CO2. This paper describes the development and application of a detailed thermodynamic model to compute and compare power requirements for various multistage compression strategies for CO2 streams containing typical impurities originating from various capture technologies associated with industrial and power emission sectors. The compression options examined include conventional multistage integrally geared centrifugal compressors, supersonic shockwave compressors and multistage compression combined with subcritical liquefaction and pumping. In order to estimate the power demand for inter-stage cooling and liquefaction a thermodynamic model based on Carnot refrigeration cycle is applied. The study shows that for all the compression options examined, the compression power reduces with the increase in the purity of the CO2 stream, while the inter-stage cooling duty is predicted to be significantly higher than the compression power demand. For CO2 streams carrying less than 5% impurities, multistage compression combined with liquefaction and subsequent pumping from ca 62bar pressure can offer higher efficiency than conventional gas-phase compression. In the case of a raw/dehumidified oxy-fuel CO2 stream of ca 85% purity, subcritical liquefaction at 62bar pressure is shown to increase the cooling duty by ca 50% as compared to pure CO2.

The influence of CO2 mixture composition and equations of state on simulations of transient pipeline decompression

In a CO2 transport pipeline, decompression can occur either due to planned maintenance or accidental rupture. We investigate the impact of modelling simplifications and assumptions regarding the purity of CO2 on the decompression of an industrial scale transport pipeline. Using industrially relevant compositions of impurities we both calculate simplified (isentropic) decompression curves as well as perform full-scale fluid simulations using models for heat transfer, friction and choked flow. Herein, we compare the use of the Peng–Robinson cubic equation of state (EOS) with the use of the highly accurate EOS-CG and GERG-2008 EOS.We find that the saturation pressure can change significantly when certain impurities are present, even when in small quantities. A simplifying assumption that CO2 is pure can therefore lead to significant underestimation of the fluid pressure during the decompression, with consequences for the prediction of running ductile fractures. The choice of EOS was found to mainly affect the velocities of the initial decompression wave, with the long-time evolution of the pipeline decompression remaining relatively unchanged. The temperature minimum did neither depend significantly on the choice of EOS nor the presence of impurities.

Further development and validation of CO2FOAM for the atmospheric dispersion of accidental releases from carbon dioxide pipelines

This paper reports on the further development and validation of CO2FOAM, a dedicated computational fluid dynamics solver for the atmospheric dispersion of Carbon Dioxide (CO2) from accidental pipeline releases. The code has been developed within the framework of the open source CFD code OpenFOAM® (OpenCFD, 2014). Its earlier version used the homogeneous equilibrium method for fully compressible two-phase flow. Validation of the code against CO2 releases through vertical vent pipes and horizontal shock tubes was previously reported by Wen et al. (2013). In the present study, the homogeneous relaxation model has been implemented as it is more suited to account for the presence of solid CO2 within the releases. For validation, the enhanced CO2FOAM has been used to predict CO2 dispersion in a range of full scale tests within the dense phase CO2 PipeLine TRANSportation (COOLTRANS) research programme (Cooper, 2012) funded by National Grid. The test case used in the present study involved a puncture in a buried pipe. The experimental measurements were supplied to the authors after the predictions were completed and submitted to National Grid. Hence, the validation reported here is indeed ‘blind’. The validated model has also been used to study the effect of a commercial building located downstream from the release location.

Research on the Hydrate Formation in the process of Gas Phase CO2 Pipeline Transportation

Research on the Hydrate Formation in the process of Gas Phase CO2 Pipeline Transportation

Budget-type techno-economic model for onshore CO2 pipeline transportation in China

CO2 pipeline transportation is a cost-effective technology for the transportation of large volumes of CO2. Numerous published techno-economic models of CO2 pipelines primarily use pipeline length and another quantity, such as pipe diameter, flow rate, and flow velocity, to predict the cost of a pipeline project. The precision of such economic models is limited by the technical characteristics of CO2 pipelines and the scarcity of statistical data from natural gas pipelines, especially in China. Therefore, building budgetary techno-economic models to assess cost with less uncertainty under increased flexible conditions is essential. A budget-type techno-economic model for an onshore CO2 pipeline was established based on existing technical guidelines, budgetary parameters, and technical characteristics of CO2 pipelines. This model can be used to provide more detailed estimates for specific CO2 pipeline projects. The cost ranges of CO2 pipelines across different regions in China were studied using deterministic and stochastic analyses. The mean values and variation ranges of levelized costs in Central, East, Northeast, North, Northwest, and South China were obtained and analyzed. This study provides highly detailed cost results for onshore CO2 pipeline projects in China.

Effect of impurity on the corrosion behavior of X65 steel in water-saturated supercritical CO2 system

A range of impurities from various CO2 capture processes may exist in supercritical CO2 transport pipeline in carbon capture and storage process. In this regard, the corrosion behavior of X65 steel in water-saturated supercritical CO2 containing O2, H2S, SO2 or NO2 impurity was investigated using weight loss measurement and surface characterization. The corrosion impact factor was defined which showed that NO2 or SO2 had the greatest influence on the corrosion of X65 steel, followed by H2S and O2. Localized corrosion occurred in water-saturated supercritical CO2 system containing NO2 with or without other impurities. Low concentrations of impurities could notably change the corrosion rate and the characteristics of corrosion scale via changing the corrosion mechanism, and thus the corrosion effect of CO2 weakened in water-saturated supercritical CO2 system containing impurities.

Modelling brittle fracture propagation in gas and dense-phase CO2 transportation pipelines

The development and application of a fluid–structure interaction model for simulating the transition of a through-wall defect in pressurised dense (150bar, 283.15K) and gas phase (34bar, 283.15K) CO2 pipelines into a running brittle fracture is presented. Given the economic incentives, the fracture model is employed to test the suitability of the existing stock of natural gas pipelines with the relatively high ductile to brittle transition temperatures of 0 and −10°C for transporting CO2 in the terms of their resistance to brittle fracture propagation. The hypothetical but nevertheless realistic scenarios simulated involve both buried and above ground 10km long, 0.6m i.d. pipelines. Based on the assumption of no blowout of the surrounding soil upon the formation of the initial leak, the results show that the transition of the leak into a running brittle fracture in buried CO2 pipelines is far more likely as compared to above ground pipelines. In addition, gas phase pipelines are more prone to undergoing a propagating brittle fracture as compared to dense phase pipelines despite the lower operating pressures of the former. Furthermore, counter-intuitively, isolation of the feed flow following the discovery of a leak is shown to facilitate brittle fracture failure. The initial defect geometry on the other hand is shown to have a profound impact on the pipeline's resistance to propagating brittle fractures.

Assessment of brittle fractures in CO2 transportation pipelines: A hybrid fluid-structure interaction model

In order to transport dense-phase CO2 captured from power and industrial emission sources in the Carbon Capture and Storage (CCS) chain, pressurised steel pipelines are considered the most practical tool. However, concerns have been raised that low temperatures induced by the expansion of dense-phase CO2, for example following an accidental puncture or during emergency depressurization, may result in a propagating brittle fracture in the pipeline steels.The present study describes the development of a hybrid fluid-structure model for simulating dynamic brittle fracture in buried pressurised CO2 pipelines. To simulate the state of the flow in the rupturing pipeline, a compressible one-dimensional Computational Fluid Dynamics (CFD) model is applied, where the pertinent fluid properties are determined using a thermodynamic model. In terms of the fracture model, an extended Finite Element Method (XFEM) is used to model the dynamic brittle fracture behaviour of the pipeline steel.Using the coupled fluid-structure model, a study is performed to evaluate the risk of brittle fracture propagation in a (real-scale) 1.22m diameter API X70 steel pipeline, containing CO2 at 0°C and 11MPa. The simulated results are found to be in good agreement with the predictions obtained using a semi-empirical model accounting for the pipeline fracture toughness. From the results obtained it is observed that a propagating fracture is limited to a short distance. As such, for the conditions tested, there is no risk of brittle fracture propagation for API X70 pipeline steel transporting dense-phase CO2.

A modelling study of the multiphase leakage flow from pressurised CO2 pipeline

The accidental leakage is one of the main risks during the pipeline transportation of high pressure CO2. The decompression process of high pressure CO2 involves complex phase transition and large variations of the pressure and temperature fields. A mathematical method based on the homogeneous equilibrium mixture assumption is presented for simulating the leakage flow through a nozzle in a pressurised CO2 pipeline. The decompression process is represented by two sub-models: the flow in the pipe is represented by the blowdown model, while the leakage flow through the nozzle is calculated with the capillary tube assumption. In the simulation, two kinds of real gas equations of state were employed in this model instead of the ideal gas equation of state. Moreover, results of the flow through the nozzle and measurement data obtained from laboratory experiments of pressurised CO2 pipeline leakage were compared for the purpose of validation. The thermodynamic processes of the fluid both in the pipeline and the nozzle were described and analysed.

Localization of CO2 leakage from transportation pipelines through low frequency acoustic emission detection

Carbon Capture and Storage is a technology to reduce greenhouse gas emissions. CO2 leak from high pressure CO2 transportation pipelines can pose a significant threat to the safety and health of the people living in the vicinity of the pipelines. This paper presents a technique for the efficient localization of CO2 leakage in the transportation pipelines using acoustic emission method with low frequency and narrow band sensors. Experimental tests were carried out on a lab scale test rig releasing CO2 from a stainless steel pipe. Further, the characteristics of the acoustic emission signals are analyzed in both the time and the frequency domains. The impact of using the transverse wave speed and the longitudinal wave speed on the accuracy of the leak localization is investigated. Since the acoustic signals are expected to be attenuated and dispersed when propagating along the pipe, empirical mode decomposition, signal reconstruction and a data fusion method are employed in order to extract high quality data for accurate localization of the leak source. It is demonstrated that a localization error of approximately 5% is achievable with the proposed detecting system.

An experimental investigation of supercritical CO2 accidental release from a pressurized pipeline

Experiments at laboratory scales have been conducted to investigate the behavior of the release of supercritical CO2 from pipelines including the rapid depressurization process and jet flow phenomena at different sizes of the leakage nozzle. The dry ice bank formed near the leakage nozzle is affected by the size of the leakage nozzle. The local Nusselt numbers at the leakage nozzle are calculated and the data indicate enhanced convective heat transfer for larger leakage holes. The mass outflow rates for different sizes of leakage holes are obtained and compared with two typical accidental gas release mathematical models. The results show that the “hole model” has a better prediction than the “modified model” for small leakage holes. The experiments provide fundamental data for the CO2 supercritical-gas multiphase flows in the leakage process, which can be used to guide the development of the leakage detection technology and risk assessment for the CO2 pipeline transportation.