Experience with CO2 capture from coal flue gas in pilot-scale: Testing of different amine solvents

AbstractAs part of the EU project CASTOR, a 1 t/h CO2 absorption pilot plant has been erected at Esbjergværket (Esbjerg power station) in Denmark. The main purpose of the pilot plant is to demonstrate the post combustion capture technology in conjunction with a coal-fired power station. Additionally, the pilot plant has been used to test the performance of new energy efficient solvents and to validate modelling work. The pilot plant operates on a slipstream of flue gas from the power plant without any further pre- treatment. During the CASTOR project, four 1000-hours test campaigns have been conducted at the facility using conventional solvent, 30%-weight MEA as well as two novel amine-based solvents, CASTOR 1 and CASTOR 2. Among others, the test campaigns consisted of parameter variation tests and longer periods of continuous operation. This paper summarises the operation experience and some of the results obtained during the CASTOR project

Short-term response of deep-water benthic megafauna to installation of a pipeline over a depth gradient on the Angolan Slope

Large structures are introduced into deep-water marine environments by several industrial activities, including hydrocarbon exploitation. Anthropogenic structures can alter ecosystem structure and functioning in many marine ecosystems but the responses on continental margins are poorly known. Here, we investigate the short-term response of benthic megafauna to the installation of a 56 km-long 30 cm diameter pipeline on the Angolan Margin (Block 31) from 700 to 1800 m water depth using remotely operated vehicle imagery. Clear depth-related patterns exist in the density, diversity and community structure of megafauna observed in 2013 prior to pipeline installation. These patterns are altered in a subsequent survey in 2014, three-months after pipeline installation. Significant increases in density, particularly in mid-slope regions are observed. Diversity is generally, but not consistently, enhanced, particularly in the shallower areas in 2014. Clear changes are noted in community structure between years. These changes are primarily caused by increases in the abundance of echinoderms, particularly the echinoid Phormosoma sp. indet. There was no evidence of colonisation of the pipeline in three months by visible fauna. The few large anemones observed attached to the pipe may be able to move as adults. The pipeline appeared to trap organic material and anthropogenic litter, and may enhance available food resources locally as well as providing hard substratum. These results indicate complex and ecosystem-dependent responses to structure installation and caution against simplistic approaches to environmental management

Performance evaluation and optimisation of post combustion CO2 capture processes for natural gas applications at pilot scale via a verified rate-based model

CO2 absorption based on chemical reactions is one of the most promising technologies for post combustion CO2 capture (PCC). There have been significant efforts to develop energy efficient and cost effective PCC processes. Given that PCC is still maturing as a technology, there will be a continuing need for pilot scale facilities to support process optimisation, especially in terms of energy efficiency. Pilot scale PCC facilities, which are usually orders of magnitude smaller than those that will be used in future in large scale fossil power plants, make it possible to study details of the PCC process at an affordable scale. However, it is essential that pilot scale studies provide credible data, if this is to be used with confidence to envisage the future large-scale use of the PCC process, especially in terms of energy consumption. The present work therefore establishes and experimentally verifies (using a representative pilot plant as a case study) procedures for analysing the energy performance of a pilot scale amine based CO2 capture plants, focusing on natural gas fired applications. The research critically assesses the pilot plant’s current energy performance, and proposes new operating conditions and system modifications by which the pilot plant will operate more efficiently in terms of energy consumption. The methodology developed to assess and improve the energy performance of the PCC process is applicable, with appropriate inputs, to other plants of this type that employs aqueous 30 wt. % monoethanolamine (MEA) solution as the solvent. A rate based model of the post combustion CO2 capture process using an aqueous solution of 30 wt. % MEA as the solvent was developed in Aspen Plus® V.8.4, and verified using the results of experimental studies carried out using the UK Carbon Capture and Storage Research Centre / Pilot-scale Advanced Capture Technology (UKCCSRC/PACT) pilot plant, as a representative pilot-scale capture plant, and employed for parametric sensitivity studies. Several parameters have been identified and varied over a given range of lean solvent CO2 loading to evaluate their effects on the pilot plant energy requirement. The optimum lean solvent CO2 loading was determined using the total equivalent work concept. Results show, for a given packing material type, the majority of energy savings can be realised by optimising the stripper operating pressure. To some extent, a higher solvent temperature at the stripper inlet has the potential to reduce the regeneration energy requirement. A more efficient packing material, can greatly improve the pilot plant overall energy and mass transfer efficiency