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Using carbon dioxide (CO 2) as a raw-material to produce value-added chemicals has a strategic role to play in the decarbonization of energy resources and the transition to a climate-neutral economy. E-methanol, Synthetic Natural Gas (SNG) and e-kerosene are one of the most promising pathways to convert CO 2. In this context, the aim of this work is to propose an optimized and integrated CO 2 to methanol process and then to compare it to the CO 2 to SNG process from economic and environmental points of views. An optimized reactor configuration in the CO 2 to methanol conversion unit has been successfully implemented in Aspen Plus® and leads to a thermal energy self-sufficiency of this unit. A heat integration with an advanced capture unit has been performed where 5 % of the heat requirement could be provided from the conversion unit while 95 % come from external steam source. Techno-economic assessment of the optimized process showed that methanol is more profitable when it is used as a raw material to synthetize other chemicals. As an energy carrier, SNG is more interesting. Compared to the reference scenario, a net CO 2 emission reduction of 70 % in the CO 2 to SNG route and of 60 % in the CO 2 to methanol route were obtained. Concerning the fossil depletion impact, in both cases, a reduction of more than 60 % was noticed (ca. 75 % in CO 2 to SNG route and 61 % in CO 2 to methanol case). • CO 2 to methanol process modeling and conceptualization. • Thermal energy self-sufficiency of the conversion unit is achieved. • Heat integration between the CO 2 conversion and capture units. • TEA and LCA analyses are performed for a relevant process evaluation. • The CO 2 to methanol process is compared to a CO 2 to synthetic natural gas one. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents an improvement of the scroll compressors model previously published by . This improved model allows the calculation of refrigerant mass flow rate, power consumption and heat flow rate that would be released at the condenser of a heat pump equipped with the compressor, from the knowledge of operating conditions and parameters. Both basic and improved models have been tested on scroll compressors using different refrigerants. This study has been limited to compressors with a maximum electrical power of 14 kW and for evaporation temperatures ranging from −40 to 15 °C and condensation temperatures from 10 to 75 °C. The average discrepancies on mass flow rate, power consumption and heat flow rate are respectively 0.50%, 0.93% and 3.49%. Using a global parameter determination (based on several refrigerants data), this model can predict the behavior of a compressor with another fluid for which no manufacturer data are available. [Copyright &y& Elsevier]

Abstract: This paper presents simple and thermodynamically realistic models of two types of compressors widely used in domestic heat pumps (reciprocating and scroll compressors). These models calculate the mass flow rate of refrigerant and the power consumption from the knowledge of operating conditions and parameters. Some of these parameters may be found in the technical datasheets of compressors whereas others are determined in such a way that the calculated mass flow rate and electrical power match those given in these datasheets. The two models have been tested on five reciprocating compressors and five scroll compressors. This study has been limited to compressors with a maximum electrical power of 10kW and for the following operating conditions: evaporating temperatures ranging from −20 to 15°C and condensing temperatures ranging from 15 to 60°C. The average discrepancies on mass flow rate and power for reciprocating compressors are 1.10 and 1.69% (for different refrigerants: R134a, R404A, R22, R12 and R407C). For scroll compressors, the average discrepancies on mass flow rate and power are 2.42 and 1.04% (for different refrigerants: R134a, R404A, R407C and R22). [Copyright &y& Elsevier]

Highlights • A CO 2 de-SOx and de-NOx process was simulated for full oxy-fuel cement plants. • A comprehensive chemical mechanism has been elucidated and implemented in Aspen. • Results of a parametric study were presented for a single-column configuration. • Optimizations depending on purity targets were achieved by economic evaluations. Abstract The purpose of the present work was to investigate, for a gas issued from a full oxy-fuel combustion in the cement industry, a CO 2 de-SOx and de-NOx process, called "Sour-Compression Unit" (SCU), thanks to simulations with Aspen PlusTM. An important stage necessary for the SCU modeling has been the construction of an accurate chemical mechanism. Two-column and single-column configurations have been evaluated and compared. A parametric study and a Design Of Experiments have been conducted on a single-column process to study the influence of the operating parameters on the SOx and NOx abatement ratios. As a demonstration of the effectiveness of the model, three SOx and NOx purity specifications (depending on the further applications of the CO 2) were applied to the purified gas. The feature of the investigated model lies on optimizing the way to reach the purity target in order to decrease installation costs (CAPEX) and energy requirements (OPEX). [ABSTRACT FROM AUTHOR]