Interests and challenges of organic solvent nanofiltration for sustainable chemistry: the case of homogeneous catalysis of metathesis

Abstract

The development of chemical reactions catalysed by homogeneous organometallic complexes has allowed a significant breakthrough in synthesis chemistry, but now research axes must integrate catalysts recycling at the early stage of their conception. Catalyst recycling by nanofiltration in organic solvent (OSN) may represent an innovative route since this separation process at a molecular level is a low energy consumer. Challenges for OSN are membrane stability in organic solvents and the mastering of filtration conditions. Molecular engineering of catalysts based on slight structural modifications is also proposed to associate activity and high retention for OSN recycling. This paper deals with the integration of OSN within the homogeneous catalytic olefin metathesis reaction.

Recovery of Valuable Solutes from Organic Solvent/Water Mixtures via Direct Contact Membrane Distillation (DCMD) as a Non-Heated Process

“…As shown in Table 3 , after two hours of operation, the leaking solute flux was less than 0.01 g/m 2 ∙h and the solute retention ratio was greater than 99.9% in all conditions. These performances were high enough to apply for solute recovery and are comparable to the conventional OSN processes [ 7 , 8 , 9 ]. The results, thereby indicate that, despite the presence of an organic solvent in the feed, the solute is recovered sufficiently.…”

“…Additionally, since OSN is a membrane technology, it is easier to scale up than the conventional distillation technologies [ 1 ]. However, because OSN membranes separate solutes by size, it is difficult to concentrate valuable resources that are smaller than the membrane pore size without incurring losses, since they easily pass through the OSN membranes [ 7 , 8 , 9 ].…”

Comparison of two nanofiltration membrane reactors for a model reaction of olefin metathesis achieved in toluene

“…Roughly and unfortunately, the modifications of the pre-catalyst did not significantly change the pre-catalyst retention [39,40]. Nevertheless, the percentage of the activated part varied with the pre-catalyst structure, opening different possibility for the reactor management.…”