The objective of this paper is to present new improvements in the knowledge of the performance of an Acid Gas Removal Unit (AGRU) installed on a floating gas production facility, thanks to a R&D program testing the influence of 3D motions and accelerations. The accurate design of the Acid Gas Removal Unit has a great importance for the profitability and success of a FLNG project. In order to limit both weight and footprint, it shall rely on the lowest possible solvent flowrate and on the minimal and optimum equipment size to treat the feed gas while taking into account motions of the floating support. The proposed paper will demonstrate how a tight but safe design of an amine unit can be proposed thanks to the results of an extensive experimental program. Total, Prosernat and IFPEN have conducted a four-year R&D program at Heriot-Watt University based on pilot tests aiming at modelization of mass transfer and hydraulics of tilting and moving towers. This program has included the testing of multiple parameters such as liquid/gas flowrates, liquid viscosity, diameter of towers, height of packing beds, packing efficiency. This has been done under various conditions: static tilt, pitch and 3D motions generated by a hexapod robot with six degrees of freedom. The motion conditions tested were similar to those experienced by a column installed on a floating gas production support or on a FLNG. The collected information on hydraulics and mass transfer showed a significant impact of motions on liquid and gas distribution along the packing beds that can, under conditions of loads of gas and liquids, lead to a significant loss of absorption performances. An in-depth analysis of the large experimental data set with a comprehensive understanding of the phenomena in place allowed the development team to propose a robust model. This model is now embedded in a rated base mass transfer proprietary simulator of AGRU that can predict with good accuracy the impact of motions of the floating support on the performance of the unit. This paper will present key results accumulated along the program about the impact of motions on liquid/gas maldistribution along a packing bed. It will explain how the accumulated knowledge enables to size tight but reliable AGRU's for installation on a floating support, in the presence of CO2, but also of other contaminants like H2S. The discussion will be supported by comprehensive examples of degradation of the absorption performances on real cases affected by sea motion.

No abstract

No abstract

3D Project, standing for DMX™ Demonstration Dunkirk, is a European funded project to demonstrate an innovative CO2 capture process at semi-industrial scale: DMX™. The 11 partners of this project gathered their forces to demonstrate the capture process and to study the CCS chain (capture, transport and Storage) allowing to decrease the CO2 emissions from industries (steel mills, refineries, waste-to-energy plants etc). Objectives/Scope Carbon capture is due to play a fundamental rote in achieving Net Zero Emissions scenario in 2050. Amine scrubbing is considered nowadays a suitable technology for the sectors with large-fixed CO2 emissions due to its robustness, adaptability, and capability of producing a highly concentrated CO2 stream, suitable to be transported. Four main challenges need to be addressed for the industrial deployment of this technology: process footprint reduction, process energy penalty reduction, solvent and VOC emission limitation and long-term process stability. Some challenges can be addressed through solvent formulation and process configuration. IFPEN has developed a novel solvent and process configuration, the DMX™ process, showing promising results in terms of energy consumption and process stability. This work aims at the demonstration of the DMX™ process by means of a set of experimental campaigns with a demonstration plant treating real gases in the frame of H2020 funded project called 3D (grant agreement n° 838031). The demonstration plant is installed in the Steel Mill of ArcelorMittal Dunkirk and will absorb CO2 present in the blast furnaces gases. The design and construction of the unit is realized under the supervision of Axens. The demonstration plant is operated by a mixed team from IFPEN and TotalEnergies. Methods, Procedures, Process The DMXTM technology is a CO2 chemical absorption process involving a demixing solvent. This process consists in the continuous operation of two sections: 1) the absorption section, in which the CO2 is captured by the lean solvent, and 2) the regeneration section, in which the rich solvent is thermally stripped from the CO2 and recirculated to the absorption section. The particularity of this process is the solvent demixing in the regeneration section. Only the CO2 rich aqueous stream is thermally stripped. In addition, since the regeneration of the solvent can be performed at a relative high temperature (150-160 °C), the DMX process produces a relatively high-pressure CO2 effluent (5-6 bara). Hence, energy and investment cost savings are expected to be obtained.

CO2 capture & storage is foreseen as a necessity to limit global warming, as indicated by the recent reports from International Energy Agency. Major initiatives have to be initiated in a near future with concrete actions to get efficient results in limiting global warming. Based on its decades of experience in gas sweetening AXENS has developed an expertise in CO2 removal technologies. While conventional amine based processes can be used for some CO2 capture applications like for instance the treatment of process gas streams under pressure, other applications for low pressure gas streams like flue gases will require innovative advanced solutions. AXENS has studied various options for the removal of CO2 in SMR based hydrogen schemes, including the treatment of the process gas or the treatment of the flue gases from the SMR furnace, evaluating the respective merits of those options. For the treatment of the flue gases a new technology developed by IFPEN and AXENS based on a second generation amine solvent is considered : DMX™ DMX™ process, is foreseen as a key contributor for the removal of CO2 from all kind of low pressure gas streams. This process allows drastic reduction of CO2 capture cost in comparison to more conventional solvent such as MEA and others available solvents. The specific features of this solvent allows significant reduction of the heat requirements for the regeneration of the solvent. It also allows regenerating the solvent directly under pressure up to 6 bara, reducing the costs for downstream CO2 compression Preliminary techno-economic studies show significant advantage of DMX™ technology relatively to MEA : up to 30 % reduction in OPEX can be obtained for lower or similar CAPEX, depending on the condition. This process has been developed at the lab scale and is now going to be demonstrated in an industrial pilot unit installed in ArcelorMittal's steel mill plant in Dunkirk (France). This demonstration benefits from the support of EU's H2020 programme, under 3D project.