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Using carbon dioxide (CO2) 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 CO2. In this context, the aim of this work is to propose an optimized and integrated CO2to methanol process and then to compare it to the CO2to SNG process from economic and environmental points of views. An optimized reactor configuration in the CO2to 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 CO2emission reduction of 70 % in the CO2to SNG route and of 60 % in the CO2to methanol route were obtained. Concerning the fossil depletion impact, in both cases, a reduction of more than 60 % was noticed (ca. 75 % in CO2to SNG route and 61 % in CO2to methanol case).

The ability of two structurally related small-pore metal–organic frameworks (MOFs) to capture CO2was investigated by a combination of gas sorption measurements, X-ray powder diffraction (XRPD) analysis, microcalorimetry experiments, and ideal adsorbed solution theory (IAST) calculations. The title solids, formulated Mg(H2gal) and Fe(Hgal) (H4gal = gallic acid), are made of a naturally occurring ligand and were both prepared on the multigram scale under mild conditions. They both present very similar structures, with identical channels of ca 3.5 Å diameter, but present different amounts of acidic protons on the surface of the pores. These compounds were found to be extremely hydrophilic and exhibit moderate stability toward the water. While their ability to adsorb CH4and N2is very limited, they both adsorb significant amounts of CO2even at atmospheric pressure (3 and 5 mmol g–1at 303 K for the Fe and Mg derivatives, respectively). As a consequence, these compounds present high CO2/N2and CO2/CH4selectivities (380–910 and 190–460, respectively) together with good working capacities, making them of interest for the capture of CO2from flue gas or for landfill gas upgrading in pressure swing adsorption or vacuum swing adsorption processes. Finally, the analysis of the Mg derivative by X-ray diffraction (XRD) and adsorption microcalorimetry revealed that its high affinity for CO2relies on a strong and specific site of adsorption involving double hydrogen bonds between the CO2molecules and the acidic protons of the framework.

The complexity of Ti chemistry in solution not only leads to the difficulty of isolating crystalline titanium metal-organic frameworks (Ti-MOFs) but also brings the challenge of controlled assembly of the crystal structure. We report here the first example of a controlled synthesis of a Ti-MOF structure through a linker-exchange strategy directly from a preformed Ti-O cluster. A Ti8O8cluster precursor with terminal formate and acetate ligands (Ti8AF) was reacted with trimesic acid (BTC) under green and mild conditions, generating a microporous Ti-MOF (MIP-207) while preserving the connection and configuration of the Ti8O8core. In addition, due to the ditopic meta-positional connection mode of the linker, the chemical environment and functionality of the structural voids could be easily tuned by substituting trimesate moieties with isophthalate-type linkers via concise one-pot reactions. This finally resulted in an adjustable performance in CO2capture over N2.

One of the most promising technologies, with a low energy penalty, for CO2capture from diverse gas mixtures is based on the adsorption process using adsorbents. Many efforts are still currently deployed to search for water stable porous metal–organic frameworks (MOFs) with high CO2affinity combined with large CO2uptake. In this context, we have selected the water stable and easily scalable Al-based MOF MIL-160 showing an ultramicroporosity and potential interacting sites (hydroxyl and furan), both features being a priori relevant to favor the selective adsorption of CO2over other gases including H2, N2, CH4, and CO. Density functional theory (DFT) and force-field-based grand-canonical Monte Carlo (GCMC) simulations were first coupled to predict the strength of host/guest interactions and the adsorption isotherms for all guests as single components and binary mixtures. This computational approach reveals the promises of this solid for the selective adsorption of CO2with respect to these other investigated gases, controlled by a combination of thermodynamics and confinement effects. These predicted performances were further supported by real-coadsorption measurements performed on shaped samples which indicated that MIL-160(Al) shows promising performance for the selective CO2capture in post- and pre-combustion conditions.

The use of porous materials to eliminate volatile organic compounds (VOCs) has proven very effective towards achieving sustainability and environmental protection goals. The activity of zeolites and macro–mesoporous metal‐oxide supports in the total oxidation of VOCs has been investigated, with and without noble‐metal deposition, to develop highly active catalyst systems where the formation of by‐products was minimal. The first catalysts employed were zeolites, which offered a good activity in the oxidation of VOCs, but were rapidly deactivated by coke deposition. The effects of the acido‐basicity and ionic exchange of these zeolites showed that a higher basicity was related to exchanged ions with lower electronegativities, resulting in better catalytic performances in the elimination of VOCs. Following on from this work, noble metals were deposited onto macro–mesoporous metal‐oxide supports to form mono and bimetallic catalysts. These were then tested in the oxidation of toluene to study their catalytic performance and their deactivation process. PdAu/TiO2and PdAu/TiO2‐ZrO280/20 catalysts demonstrated the best activity and life span in the oxidation of toluene and propene and offered the lowest temperatures for a 50 % conversion of VOCs and the lowest coke content after catalytic testing. Different characterization techniques were employed to explain the changes occurring in catalyst structure during the oxidation of toluene and propene.

The adsorption of the acid gas H2S has been explored in both MIL-47(V) and MIL-53(Cr) porous metal−organic frameworks (MOFs) by combining infrared measurements and molecular simulations. It is shown that while the MIL-47(V) structure remains rigid upon H2S adsorption up to a pressure of 1.8 MPa, the MIL-53(Cr) solid initially present in the large pore form (LP) switches to its narrow pore version (NP) at very low pressure before undergoing a second structural transition from the NP to the LP versions at higher pressure. Such structural transitions further explain the different shape of the adsorption isotherms for both MILs. A further step consists of providing some insights into the microscopic arrangements of the adsorbate molecules within the pores of the MILs. At the initial stage of adsorption, the H2S molecules mainly form hydrogen bonded species, either as hydrogen donor (in MIL-47 V) or hydrogen-acceptor (in MIL-53Cr) with the μ2-O and μ2-OH groups, respectively, present at the MOF surfaces. At higher pressure (1.8 MPa), the adsorbates are preferentially arranged within the channel in order to form dimers with a high orientational disorder. Both experimental and simulated adsorption enthalpies for H2S decrease in the following sequence: MIL-53(Cr) NP > MIL-47(V) > MIL-53(Cr) LP. The conclusions drawn from this work are then discussed considering the use of such materials for the CH4/H2S separation by means of Pressure Swing Adsorption.

Abstract In this work, we present a complete experimental procedure which aims at measuring adsorption isotherms, selectivity curves and kinetics of air compounds on porous media in broad ranges of pressure and temperature. The experimental set-up and the experimental procedures are presented as well as a complete report on treatments of the rough experimental results to obtain the adsorption isotherms, selectivity and kinetics curves. Results are provided for nitrogen/LiLSX and oxygen/LiLSX systems (adsorption isotherms curves at 278 and 303 K in the pressure range 0–400 kPa), for a binary mixture nitrogen/oxygen/LiLSX system at 303 K and 400 kPa (selectivity curves). Kinetics curves are presented for nitrogen/LiLSX and oxygen/LiLSX systems at 303 K and 400 kPa.

Abstract In this paper, we present a new experimental technique and a mathematical procedure for the calculation of the isosteric heats of adsorption of VOC-zeolite systems. This procedure provides a continuous isosteric heat curve over a large coverage ratio range including the low-coverage area. Results are given for a toluene-NaY system at 423 K. The validity of the method is discussed by comparison with other methods.

In this paper we present adsorption isotherms of carbon dioxide on five different activated carbons from CHEMVIRON CARBON Belgium (Centaur HSV, BPL 410, F30-470, WS 42, Reactivated) and on a carbon molecular sieve from BERGBAU FORSCHUNG Gmbh (CMS II). The temperature is 303 K and the pressure ranges from 100 kPa up to 4000 kPa. Such conditions correspond to relative pressures ranging from 0.01 to 0.5. We also provide, for the same six sorbents, the nitrogen isotherms at 77 K (pressure: 0.001 to 100 kPa, relative pressure: 10-5to 1). A theoretical treatment based on the Dubinin-Radushkevich and Stoeckli concept is presented and applied to the experimental results in order to obtain the micropore size distribution function (considered as Gaussian) of each sorbent. Using the CO2data, it is possible to point out important structural differences between the six carbons. The theoretical treatment provides micropore size distribution functions in agreement with what is physically expected. Using N2data, the structural differences are not so well marked. As a consequence, the structural parameters provided by the theoretical treatment are not reliable: except for the total micropore volume, they fluctuate strongly when changing the relative pressure domain of the used data.

•Process modeling and conceptual design are implemented using Aspen Plus.•Techno-economic and environmental analyses are conducted for performances evaluation.•Thermal energy self-sufficiency is achieved through an optimized integrated process.•Overall energy efficiency reaches 89.5% on a LHV basis.•Drastic reductions in terms of net CO2emissions and fossil depletion are observed.

Carbon dioxide utilization is increasingly attracting interest. CO2utilization involves a multitude of processes and chemical reactions. In this context, the goal of this review is to analyze the techno‐economic feasibility, sustainability, and social opportunities of CO2utilization, as a possible contribution to CO2mitigation in Europe. Industries and the most recent European projects related to carbon capture and utilization are also discussed, illustrating Europe's performance dynamics in science, research, and innovation in this field. The latest developments in CO2utilization are thus reviewed, including chemicals, mineral carbonation, and biological uses. This study examines a few CO2‐based pathways at high level of maturity covering a wide range of applications, and discusses their current technical feasibility, economic viability, sustainability, and social aspects. They are then evaluated using several indicators to provide a figure of merit, where qualitative results are intended. The mapping and ranking of CO2utilization pathways may provide a valuable means in prioritizing support and funding to facilitate the development of large‐scale CO2utilization projects in Europe. Finally, key challenges and opportunities are discussed. The review shows that CO2utilization may not be a complete solution for Europe, but will support climate change objectives, circular economy, and resource and energy security. This review focuses on technologies that transform CO2into useful products. Herein, several CO2utilization technologies are examined from four perspectives: technical feasibility, economic viability, sustainability, and social aspects. Key challenges and opportunities are also discussed, showing that such technologies may support climate change objectives, circular economy, and resource and energy security in Europe.

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