Challenges in CO₂ transportation: Trends and perspectives

Transportation of CO2 is essential for multiple applications in Carbon Capture, Utilisation and Storage (CCUS), e.g., for utilisation in methanol production, enhanced oil recovery, or permanent storage. Currently, the CCUS industry is still in its fancy, and the transportation regulation is still defined from project to project, where the existing quality specifications are tailored to the specific storage or utilisation site. It is estimated that transportation accounts for 25% of the total costs of a CCUS project, and commercialisation cannot be achieved with an infrastructure of high-grade steel together with high purity CO2. The current transportation infrastructure is based on point-to-point transport, where it is believed that it will be challenging to upscale CCUS without a common quality standard. This leaves a knowledge gap in the design, operation, and investment of CO2 transportation. This study includes an evaluation of the challenges that halt the progression in CO2 transportation based on a survey of the literature. Analysing the benefit of establishing an international quality standard for CO2 transportation for CCUS to become a global industry. A detailed description of the initiative policies within CCUS along with the challenges associated with designing the CO2 transportation infrastructure, which arises when chemical reactions form corrosive or scaling compounds. As a result, this study proposes a future action plan to make CO2 transport more feasible by forming a common CO2 quality specification and a material selection based on CO2 quality.Transportation of CO₂ is essential for multiple applications in Carbon Capture, Utilisation and Storage (CCUS), e.g., for utilisation in methanol production, enhanced oil recovery, or permanent storage. Currently, the CCUS industry is still in its fancy, and the transportation regulation is still defined from project to project, where the existing quality specifications are tailored to the specific storage or utilisation site. It is estimated that transportation accounts for ~25% of the total costs of a CCUS project, and commercialisation cannot be achieved with an infrastructure of high-grade steel together with high purity CO₂. The current transportation infrastructure is based on point-to-point transport, where it is believed that it will be challenging to upscale CCUS without a common quality standard. This leaves a knowledge gap in the design, operation, and investment of CO₂ transportation. This study includes an evaluation of the challenges that halt the progression in CO₂ transportation based on a survey of the literature. Analysing the benefit of establishing an international quality standard for CO₂ transportation for CCUS to become a global industry. A detailed description of the initiative policies within CCUS along with the challenges associated with designing the CO₂ transportation infrastructure, which arises when chemical reactions form corrosive or scaling compounds. As a result, this study proposes a future action plan to make CO₂ transport more feasible by forming a common CO₂ quality specification and a material selection based on CO₂ quality

Control-Oriented Modeling and Experimental Validation of a Deoiling Hydrocyclone System

As the treated water from offshore oil and gas production is discharged to the surrounding sea, there is an incentive to improve the performance of the offshore produced water treatment, to reduce the environmental pollutants to the sea. Regulations determine both the maximum allowed oil concentration and the total annual quantity. It is reasonable to assume that when better separation equipment or methods are developed, the regulation will become more strict, and force other producers to follow the trend towards zero harmful discharge. This paper develops and validates a hydrocyclone model to be used as a test-bed for improved control designs. The modeling methodology uses a combination of first-principles to define model structure and data-driven parameter identification. To evaluate and validate the separation performance, real-time fluorescence-based oil-in-water (OiW) concentration monitors, with dual redundancy, are installed and used on sidestreams of a modified pilot plant. The installed monitors measure the inlet and outlet OiW concentration of the tested hydrocyclone. The proposed control-oriented hydrocyclone model proved to be a reasonable candidate for predicting the hydrocyclone separation performance

Hammerstein–Wiener Model Identification for Oil-in-Water Separation Dynamics in a De-Oiling Hydrocyclone System

To reduce the environmental impact of offshore oil and gas, the hydrocarbon discharge regulations tend to become more stringent. One way to reduce the oil discharge is to improve the control systems by introducing new oil-in-water (OiW) sensing technologies and advanced control. De-oiling hydrocyclones are commonly used in offshore facilities for produced water treatment (PWT), but obtaining valid control-oriented models of hydrocyclones has proven challenging. Existing control-oriented models are often based on droplet trajectory analysis. While it has been demonstrated that these models can fit steady-state separation efficiency data, the dynamics of these models have either not been validated experimentally or only describe part of the dynamics. In addition to the inlet OiW concentration, they require the droplet size distribution to be measured, which complicates model validation as well as implementation. This work presents an approach to obtain validated nonlinear models of the discharge concentration, separation efficiency, and discharge rate, which do not require the droplet size distribution to be measured. An exhaustive search approach is used to identify control-oriented polynomial-type Hammerstein–Wiener (HW) models of de-oiling hydrocyclones based on concentration measurements from online OiW monitors. To demonstrate the effectiveness of this modeling approach, a PI controller is designed using the Skogestad internal model control (SIMC) tuning rules to control the discharge OiW concentration directly. The identification experiment emulates an offshore PWT system with installed OiW monitors, which is realistic with the legislative incentive to include online OiW discharge measurements. The proposed approach could enable the application of OiW-based control on existing offshore PWT facilities, resulting in improved de-oiling performance and reduced oil discharge