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The present work was focused on the application in the cement industry of the post-combustion CO 2 capture technology using amine-based chemical absorption. Besides conventional conditions, investigations were performed on a concept called “partial oxy-fuel combustion” applied to cement kilns leading to more CO 2 -concentrated flue gas (y CO2 up to 60%) and allowing to reduce the solvent regeneration energy consumption. The purpose of the study was to highlight and evaluate this reduction. Firstly, the performances of several solvents were evaluated thanks to screening tests at lab (results with a cables-bundle contactor) and micro-pilot (absorption-regeneration unit) scales considering different CO 2 contents (y CO2,in = 20-60 vol.%). Simple and blended solvents were tested in such conditions, such as primary and secondary alkanolamines (benchmark Monoethanolamine (MEA), Diethanolamine (DEA) and cyclical di-amine (Piperazine (PZ)). It was shown that the use of activated solutions (such as DEA 30 wt.% + PZ 5 wt.%) presented particularly high absorption performances both in conventional and high CO 2 contents conditions. Secondly, Aspen Hysys TM simulations were carried out considering cement plant flue gas. For MEA 30 wt.% an increase of y CO2 from 20% to 44% leads to a 26% decrease of the regeneration energy (from 3.36 to 2.48 GJ/t CO2 ), which is clearly encouraging. As perspectives, new absorption-regeneration tests at micro-pilot scale and simulations will be performed with other solvents in order to have a more global evaluation of the interest of partial oxy-fuel conditions for the cement industry. [ABSTRACT FROM AUTHOR]

In the context of Carbon Capture Storage (CCS) or Utilization (CCU), the application of a CO 2 Purification Unit (CPU) previously developed for oxyfuel power plants is here tested on flue gases coming from oxyfuel cement plants thanks to simulations with Aspen Plus TM . The CPU block is divided into three CO 2 purification steps. The compressed gas is firstly desulfurized and denitrified in a double-column (operating at 15 bar for the first column and 30 bar for the second one) unit called “Sour-Compression Unit” (SCU) where it is purified counter-currently with water to remove SO x and NO x components by a reactive absorption. Further treatments include a water adsorption step, and finally a separation step using either a distillation column or a double flash unit, to remove the residual inert gases. The present communication will be focused on the first step of the CPU, the “Sour-Compression Unit”. For this purpose, an accurate chemical mechanism was constructed based on literature reviews and critical comparison of various sources in order to represent properly the removal of SOx and NOx components and evaluate the performances of the SCU. Simulation results of this quite innovative application to cement plant flue gases are given and discussed. Future works will include an energetic and economic optimization of the SCU for the cement plant case. [ABSTRACT FROM AUTHOR]

Carbon Capture and Utilization (CCU) is one of the most widely studied technology to reduce anthropogenic CO 2 emissions and particularly the ones coming from power plants and cement plants which are currently among the world's main industrial sources of carbon dioxide. As a result, this study focuses on the optimization of an overall CCU process that should be applied to an oxyfuel cement plant, and including the CO 2 capture from flue gases and its purification in order to obtain a rich CO 2 stream that will be further converted into methane, methanol, or other chemically valuable compounds. To investigate the feasibility of such as process, two units (namely sour compression and cryogenic units) have been modeled and simulated on Aspen Plus software. These simulations were conducted considering flue gases compositions coming from both power and cement oxyfuel plants in order to compare their respective energy demands with regard to the CO 2 purity of the end-of-pipe product and to the CO 2 recovery of the overall process. It was observed that such process applied to simulated oxyfuel cement plant flue gases has a global CO 2 recovery range of 75.8 – 93.8% and that the CO 2 molar purity of the final stream is between 94.8 and 98.4%. This process appears to be completely applicable for the treatment of oxyfuel cement plant flue gases with CO 2 recovery and CO 2 molar purity in agreement with requirements for the chemical conversion of carbon. [ABSTRACT FROM AUTHOR]

• High CO 2 contents flue gases. • Both simple and activated solutions investigated in partial oxy-fuel conditions. • Simulation of absorption-regeneration CO 2 capture process. • Aspen Hysys™ simulations validated thanks to micro-pilot experimental results. • Significant energy savings. The present study is focusing on the investigation, for the cement industry, of the post-combustion CO 2 capture process using amine(s)-based solvents. The novel aspect of the work is the flue gas considered, namely the high CO 2 contents (between 20 and 60 vol.%), representative of flue gases coming from oxygen-enriched air combustion process (also called partial oxy-fuel combustion). Using the results of preliminary solvents screening tests at laboratory scale, absorption-regeneration micro-pilot experiments were carried out for the best solvents in order to characterize their respective absorption and regeneration performances. The use of the activated solution of DEA (diethanolamine) 30 wt.% with PZ (piperazine) 5 wt.% led to particularly high absorption performances in all CO 2 concentration range. Besides the experimental measurements, Aspen Hysys™ simulations of the micro-pilot tests were performed for three solvents (monoethanolamine (MEA) as the reference case, then PZ and DEA + PZ) to validate the models implemented. Finally, the validated models were used to perform industrial scale simulations. These simulations confirmed that both the regeneration energy, the equivalent work and the operating costs are reduced when the absorption-regeneration process is implemented to flue gases with high CO 2 contents. [ABSTRACT FROM AUTHOR]