We report herein the upscaled synthesis and shaping of UiO66-COOH for NH3 air purification. The synthesis of the zirconium-based MOF was carried out in a batch reactor in an aqueous suspension with a yield of 89% and a spacetime yield of 350 kg/day/m 3. Neither toxic chemicals nor organic solvents were used, allowing this MOF to be employed in individual or collective air purification devices. Freeze-granulation and extrusion shaping techniques were investigated. The NH3 air purification performances of UiO66-COOH in bead, tablet and extrudate forms were compared to those of commercial carbon based materials (type K adsorbents from3M and Norit). Testing conditions were chosen to reflect current standards for ammonia concentration (600-1200 ppm) and velocity. In addition, the breakthrough measurements were carried out at three different relative humidity levels (0%, 40% and 70%). Pellets and extrudates of UiO66-COOH outperformed commercial benchmark adsorbents in all conditions, especially in dry conditions, for which the commercial adsorbents suffered impaired ammonia uptake and shortened service life. Extrudates of UiO66-COOH also withstood attrition after intensive shaking.

Air purification of ammonia, a toxic industrial chemicals (TICs), by adsorption process on Metal-Organic Framework solids is attracting high scientific and commercial interests. While active carbon based adsorbents required high level of relative humidity for achieving proper performance ammonia capture, zeolite performance degrades in presence of humidity. For MOFs, the presence of humidity has been shown to be MOF dependent, either beneficial or detrimental. It appears that the role of humidity is of key importance and that different ammonia adsorption mechanisms co-exist depending on the material's physico-chemical features. Based on a screening of various microporous adsorbents including carbons, zeolites and MOFs, we show that in the presence of humidity, the ammonia uptake

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This study addresses the modeling of exchange isotherms for faujasite-type zeolites X and Y with K, Cs, Ca and Ba cations based on a large experimental dataset obtained under operating conditions of 0.5 N total normality and an exchange temperature of 80 °C. The isotherm models are based on the mass action law. Ideal solution phase is assumed. Heterogeneity of the solid phase is taken into account by using Barrer and Klinowski's approach to multi-site exchange. Three types of exchange sites are identified on these zeolites. To each exchange site j corresponds a fitted selectivity coefficient K. These parameters, estimated by least square method, evaluate the affinity of the studied cations for the identified exchange site. Globally, these fitted coefficients show that the cations considered present better affinity than Na, especially for type III sites in faujasite X and type II sites in faujasite Y. For bivalent cations, an exchange with Ba is always more favorable than with Ca. On faujasite X, type II sites are more strongly preferred by monovalent cations (with the exception of Cs) than by bivalent ones. The opposite trend is observed on faujasite Y, even for Cs. These conclusions have been confirmed and are supported by bibliographic data.

Streamlining the xylene separation process on faujasites is a promising way to design innovative adsorbents for this application. For this purpose, we present herein an original quantitative structure-property relationship (QSPR) approach. It deals with the development of a multi-linear predictive model correlating the separation properties with a set of structural descriptors for the adsorbents. The implementation of such an approach makes it necessary to (i) set an appropriate design of experiment (DOE), (ii) prepare an adsorbent database, (iii) test the adsorbent database for xylene separation and (iv) compute a set of relevant descriptors. The selected descriptors essentially characterize the nature of the confinement in the faujasite supercage, i.e., the size of the cations localized in adsorption sites II, as well as the occupancy ratio of both adsorption sites II and III. Two different statistical methods were applied to develop a structure-property relationship model linking experimental selectivity and the set of descriptors. A multiple linear regression model enables the prediction of para/meta-xylene selectivity with a correlation coefficient R2 of 0.78, while a linear discriminant analysis predicts the assignment of the adsorbents to four identified classes with a total prediction percentage of 76%.

In the current energy transition scenario, gas represents one of the main pillars for a greener energy mix. In 2015, we presented two promising schemes to produce a challenging notional gas field located 2500 meters water depth and 300 km from shore using only subsea processing [1]. The first scheme consists of subsea gas/liquid separation, gas compression and liquid boosting for multiphase export to shore; the second, developing a subsea high-pressure dehydration system for up to 300 Bara, using adsorption, to avoid the use of a monothylene glycol (MEG) loop and export dry gas directly from subsea. Performance of desiccants at such high pressure has not been studied thoroughly and qualification was necessary. This paper presents the proof-of-concept of a subsea dehydration technology at high pressure. Several criteria were used to evaluate the potential technologies: treatment performance, power consumption, production at varying pressure, sensitivity to feed contaminants, CAPEX, OPEX, weight & size, among others. The preferred solution was concluded to be temperature swing adsorption (TSA). Once TSA was selected as the most promising dehydration technology, different laboratory tests were performed and several parameters were identified to screen the potential desiccants: adsorbent working capacity, water/CH4 selectivity, water adsorption energy and regeneration temperature. Finally, a pilot was built and a test matrix was run in order to prove the concept. The adsorption, and specifically a TSA Process, was the technology selected in the first part of the study. The choice was based mainly on the energy efficiency and the technology readiness level. In the second part of this project, the feasibility of the process at high pressure (up to 300 Bara) and its application subsea were proven through experimental tests performed at a laboratory pilot. Characterization tests and water and methane adsorption/desorption isotherms are briefly presented. Based on these results, zeolite, alumina and activated carbon adsorbents were identified. Finally, complete adsorption/desorption cycles at different pressures and temperatures were performed, proving the concept and its potential. This is the first study proving experimentally the concept, and presenting the potential, of the TSA Process for subsea dehydration at high pressure. This is one of the subsea processing building blocks identified in many gas field architectures and it is especially required to produce remote and deep reservoirs at competitive costs.