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Abstract: Pre-combustion capture of carbon dioxide (CO2) from synthesis gas has been demonstrated using a solvent absorption pilot plant. The plant was designed to capture 30–50kg/h (∼1tonne/day) of CO2 from 300kg/h of syngas. The solvent used in these trials was a potassium carbonate (K2CO3) solution. Potassium carbonate shows promise as a solvent for CO2 capture because it requires lower energy for regeneration and has a low environmental impact when compared with the traditional amine-based solvents. However, the rate of CO2 absorption in K2CO3 is slow and as such there have been several studies evaluating rate promoters for this process. Boric acid has been identified as one such promoter. The pilot plant in this study was successfully operated on a campaign basis for 16 days using both an un-promoted 30wt% K2CO3 solution as well as a 30wt% K2CO3 solution promoted with 3wt% boric acid. There was no net improvement in the absorption of CO2 observed in the presence of boric acid. This result is attributed to the boric acid having reduced the pH and therefore OH− concentration of the system, which in turn reduced the rate of the controlling kinetic reaction to form potassium bicarbonate (KHCO3) from CO2. Changes in the solvent physical properties, due to interaction with syngas impurities, were found to influence the hydrodynamic performance of the packed columns. Bicarbonate precipitation and vessel level control issues also led to operational difficulties. ASPEN Plus™ simulations have been developed to predict the performance of the plant. In general the model predicts the performance of the plant well (to within ±5%) and will be important for future process development, design and optimisation. [Copyright &y& Elsevier]

Abstract: Commissioned in 2009, the CO2CRC/H3 Capture Project is demonstrating post-combustion carbon capture (PCC) on a lignite fired power plant in the Latrobe Valley, Victoria, Australia. The facility is located within International Power’s Hazelwood Power Plant and uses three different CO2 capture technologies — solvent, adsorption and membrane processes. This project, addressing the PCC issues specific for Victorian brown coal fired power stations, was initiated in July 2007 as a three year research project by the Cooperative Research Centre for Greenhouse Gas Technologies (CO2CRC) under the Victorian State Government’s Energy Technology Innovation Strategy (ETIS) program. The project is part of the Latrobe Valley Post Combustion Capture (LVPCC) Project — a multi site, multi scale, multi technology PCC trial. The integrated research and development program includes an evaluation of these technologies for commercial scale application. This paper describes the technologies used, how they have progressed from laboratory to pilot demonstration, the main outcomes, and plans for future developments. [Copyright &y& Elsevier]

Abstract: The Mulgrave capture project, which is funded under the Victorian Government’s Energy Technology Innovation Strategy (ETIS) program, has the objective of demonstrating technologies designed to capture carbon dioxide (CO2) from synthesis gas (syngas) produced from the air-blown gasification of brown coal. The technologies being investigated include solvent absorption, membrane-based solvent absorption, membrane gas separation and gas adsorption. Each technology was successful in demonstrating capture of CO2 from syngas during three separate campaigns, which were completed from May 2009 until July 2010. The performance data and operational knowledge obtained from the Mulgrave capture project will be central to future larger scale project work undertaken by the CO2CRC and partners. [Copyright &y& Elsevier]

Abstract: A 25 TPD post-combustion CO2 capture plant for brown coal and a 0.5TPD pre-combustion CO2 capture IGCC process have been designed and are being built in Victoria, Australia to assess developments in solvent absorption capture technologies. In this paper, the flowsheets developed for these processes will be discussed along with the underpinning research in the following areas: [•] New contact equipment — recent work has shown that the SMR packing has enhanced performance over structured packing and standard Pall rings. [•] The influence of promoters to enhance kinetics - using a wetted-wall column, experiments have been conducted with boric acid added to potassium carbonate solvent with results showing an enhancement in CO2 absorption rates. [•] The influence of flue gas impurities - post-combustion impurities, including SO x and NO x , have been studied with potassium carbonate to evaluate their effects on CO2 absorption. [•] Process modeling — ASPEN Plus™ simulations have been developed to predict column performance and the effects of impurities on the equilibrium relationship. [Copyright &y& Elsevier]

Abstract: Pre-combustion carbon capture separates carbon dioxide from syngas before combustion. Rubbery polymeric membranes offer the ability to separate carbon dioxide from syngas, and in particular hydrogen, with reasonable selectivity. Here, the gas separation performance of three rubbery polymeric membranes, poly dimethyl siloxane (PDMS), cross-linked polyethylene glycol (PEG) and poly (ether-b-amide) (PEBAX 2533), are reported upon exposure to real unshifted syngas, as part of the CO2CRC Mulgrave capture project. At low temperatures, all three membranes were able to separate CO2 from syngas; however competitive sorption by other syngas components significantly altered their performance relative to reported laboratory results. For PDMS, under syngas conditions CO2 permeability was reduced compared to the pure gas permeability, but CO2/H2 and CO2/N2 selectivity were improved in the presence of syngas. This resulted in good CO2 separation performance for this membrane. However over 24h of exposure the performance decreased somewhat. In contrast, both PEG and PEBAX membranes demonstrated poor CO2 separation performance upon exposure to syngas. In particular, low CO2/H2 selectivities where observed, indicating that both membranes upon exposure to syngas had poor selective ability. [Copyright &y& Elsevier]