Impact of CO₂ impurity on CO₂ compression, liquefaction and transportation

Abstract The impurities present in carbon dioxide (CO2) streams for Carbon Capture and Storage (CCS) schemes are extremely important for CO2 pipeline and ship transportation affecting, for instance, the range of operation, safety considerations, fracture, cracking, corrosion control, dispersion in the event of a release, fluid density, operating pressure and temperature and the quantity of CO2 that can be transported. The range and levels of potential impurities present in captured CO2 from CO2 capture facilities will differ between sources and also between the capture technologies installed at the CO2 emission sources. However, the potential CO2 specifications that could enter the transport and storage systems, particularly from industrial sources, remain relatively under-researched. Consequently, the effect of these potential impurities in CO2 streams on CO2 transportation also needs to be understood. This paper summarises the main findings of an IEAGHG study, “Impact of CO2 Impurity on CO2 Compression, Liquefaction and Transportation”, commissioned to identify potential impurities and address the consequences of their impact on CO2 transportation

Process Simulation of Impurity Impacts on CO2 Fluids Flowing in Pipelines

YesCaptured carbon dioxide flowing in pipelines is impure. The impurities contained in the carbon dioxide fluid impact on the properties of the fluid. The impact of each impurity has not been adequately studied and fully understood. In this study, binary mixtures containing carbon dioxide and one impurity, at the maximum permitted concentration, flowing in pipelines are studied to understand their impact on pipeline performance. A hypothetical 70 km uninsulated pipeline is assumed and simulated using Aspen HYSYS (v.10) and gPROMS (v.5.1.1). The mass flow rate is 2,200,600 kg/h; the internal and external diameters are 0.711 m and 0.785 m. 15 MPa and 9 MPa were assumed as inlet and minimum pressures and 33 oC as the inlet temperature, to ensure that the fluid remain in the dense (subcritical or supercritical) phase. Each binary fluid is studied at the maximum allowable concentration and deviations from pure carbon dioxide at the same conditions is determined. These deviations were graded to rank the impurities in order of the degree of impact on each parameter. All impurities had at least one negative impact on carbon dioxide fluid flow. Nitrogen with the highest concentration (10-mol %) had the worst impact on pressure loss (in horizontal pipeline), density, and critical pressure. Hydrogen sulphide (with 1.5-mol %) had the least impact, hardly changing the thermodynamic properties of pure carbon dioxide

The Importance of Dynamic Simulation on the Design and Optimization of Pipeline Transmission Systems

Traditionally, pipeline transmission systems have been designed using steady state simulations. Steady state simulations are sufficient for optimizing a pipeline when supply/demand scenarios are relatively stable. In the case of a gas pipeline, it is also important that flows in and out of storage are not highly variable. In general, steady state simulations will provide the designer with a reasonable level of confidence when the system is not subject to radical changes in mass flow rates or operating conditions."/jats:p" "jats:p"However, situations do arise which require more than a conventional analysis such as large load factors, surges in mass flow rates, the loss of facilities and facility operation (e.g. pigging procedures). In these and other instances, the designer will want to perform a dynamic (or transient) analysis to test the capability of the system, choose the system components and maintain the appropriate level of safety."/jats:p" "jats:p"This paper will illustrate the importance of transient simulations when designing transmission systems subject to aggressive conditions. Example scenarios, taken from current major projects, are used to depict a diverse range of dynamic problems. The examples help identify the need for a transient analysis and exemplify the downfalls in a system when the analysis is not employed during the optimization and design process

High Pressure Gas Pipelines: Trends for the New Millennium

The end of the 20th century has seen some major developments to the business of pipelines worldwide. In North America and Europe the trend has been toward deregulation of the industry. In other markets the trend has been toward the use of fixed transport cost contracts between shippers and the pipeline company. The net effect of these changes is increased competition in the transport of energy with the resulting requirement to provide the lowest cost of transport. At the same time pipelines need to maintain the traditionally high levels of safety and reliability that customers, the public and regulators have been accustomed to."/jats:p" "jats:p"The pipeline industry has responded to the challenge to reduce costs on a number of fronts. These include the areas of contracting, financing, planning, regulation, market development, and technical developments as well as many other areas. This paper will focus on technical developments that have allowed pipeline companies to reduce the cost of moving large volumes of natural gas at high pressures. Progress that the industry has made in the areas of capital cost reduction will be illustrated by an example of high pressure pipeline design. Capital costs will be compared for five system design pressures that all result in the same maximum flow rate. The optimum high-grade steel will be chosen for each pressure. This will also be compared to costs for using Composite Reinforced Line Pipe (CRLP) a new technology for the pipeline industry