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Optimization and scaling up of the Baeyer-Villiger oxidation of 3,3,5-trimethyl-cyclohexanone to trimethyl-ϵ-caprolactones (CHLs) were studied to demonstrate this technology on a 100 L pilot plant scale. The reaction was catalyzed by a cyclohexanone monooxygenase from Thermocrispum municipale that utilizes the costly redox cofactor nicotinamide adenine dinucleotide phosphate (reduced form), which was regenerated by a glucose dehydrogenase (GDH). As a first stage, different cyclohexanone monooxygenase formulations were tested: cell-free extract, whole cells, fermentation broth, and sonicated fermentation broth. Using broth resulted in the highest yield (63%) and required the least biocatalyst preparation effort. Two commercial glucose dehydrogenases (GDH-105 and GDH-01) were evaluated, resulting in similar performances. Substrate dosing rates and biocatalyst loadings were optimized. On a 30 mL scale, the best conditions were found when 30 mM h-1 dosing rate, 10% (v/v) cyclohexanone monooxygenase broth, and 0.05% (v/v) of glucose dehydrogenase (GDH-01) liquid enzyme formulation were applied. These same conditions (with oxygen instead of air) were applied on a 1 L scale with 92% conversion, achieving a specific activity of 13.3 U gcell wet weight (cww) -1, a space time yield of 3.4 gCHL L-1 h-1, and a biocatalyst yield of 0.83 gCHL gcww -1. A final 100 L demonstration was performed in a pilot plant facility. After 9 h, the reaction reached 85% conversion, 12.8 U gcww -1, a space time yield of 2.7 g L-1 h-1, and a biocatalyst yield of 0.60 gCHL gcww -1. The extraction of product resulted in 2.58 kg of isolated final product. The overall isolated CHL yield was 76% (distal lactone 47% and proximal lactone 53%). © 2019 American Chemical Society., The research in this work has received funding from the European Union project ROBOX (grant agreement no. 635734) under EU’s Horizon 2020 Programme Research and Innovation actions H2020-LEIT BIO-2014-1. This document reflects only the authors’ view and the agency is not responsible for any use that may be made of the information it contains. The Department of Chemical, Biological and Environmental Engineering of Universitat Autònoma de Barcelona constitutes the Biochemical Engineering Unit of the Reference Network in Biotechnology and the research group 2017 SGR 1462, Generalitat de Catalunya. The authors thank COST Action CM 1303: Systems Biocatalysis for financial support and Marie Delgove et al. from the University of Maastricht for providing analytical standards. J.S. also acknowledges UAB for funding his Ph.D. grant.

An electrochemical reactor was developed to recover zinc from the spent pickling solutions coming from the hot dip galvanizing industry. These solutions mainly contain ZnCl2 and FeCl2 in aqueous HCl media. The effect of the applied potential on the figures of merit (fractional conversion, current efficiency, space-time yield and specific energy consumption) of the electrochemical reactor was analysed. Voltammetric experiments were performed previously in order to select the optimum conditions to be applied in the electrolysis experiments. From the I-V curves it was inferred that bulk zinc deposition started from potential values more cathodic than -0.99 V. The hydrogen evolution reaction (HER) appeared from -0.45 V and masked the zinc cathodic peak C1, related to bulk zinc deposition, at high HCl concentrations. The presence of HCl inhibited iron deposition in synthetic samples. The additives present in the real baths, which diminish the massive hydrogen generation, allowed the observation of peak C1. The potential values to be applied in the electrolysis experiments were chosen from the voltammetric experiments and ranged between -1 V and -1.75 V. In the absence of iron in solution, as the electrode potential was shifted towards more negative values, the space-time yield of zinc and its fractional conversion increased because of the increase in the electrode roughness and the hydrogen turbulence-promoting action. Simultaneously, the specific energy consumption decreased initially due to the increase in the zinc conversion rate but decreased for the most cathodic potential value due to HER. The presence of iron in synthetic solutions led to a decrease in current efficiency associated with the reverse redox Fe 2+/Fe3+ system and to the enhancement of the HER, which also induced increments in the local pH and the subsequent zinc redissolution for the most cathodic potential values. On the contrary, the additives present in the real spent pickling baths avoided the adverse effects of iron, and zinc electrodeposition was possible even at high cathodic potential values. In fact, a potential value of -1.75 V was selected as the optimum since the conversion, the current efficiency and the space time yield obtained in the real baths were relatively high., Authors want to express their gratitude to the Universidad Politecnica de Valencia for the economical support in the project reference PAID-06-08, and to the Generalitat Valenciana for the financing of the project reference GV/2010/029.

PMCID: PMC4902134, The exceptional porosity of Metal-Organic Frameworks (MOFs) could be harnessed for countless practical applications. However, one of the challenges currently precluding the industrial exploitation of these materials is a lack of green methods for their synthesis. Since green synthetic methods obviate the use of organic solvents, they are expected to reduce the production costs, safety hazards and environmental impact typically associated with MOF fabrication. Herein we describe the stepwise optimisation of reaction parameters (pH, reagent concentrations and reaction time) for the room temperature, water-based synthesis of several members of the CPO-27/MOF-74-M series of MOFs, including ones made from Mg(ii), Ni(ii), Co(ii) and Zn(ii) ions. Using this method, we built MOFs with excellent BET surface areas and unprecedented Space-Time Yields (STYs). Employing this approach, we have synthesised CPO-27-M MOFs with record BET surface areas, including 1279 m2 g-1 (CPO-27-Zn), 1351 m2 g-1 (CPO-27-Ni), 1572 m2 g-1 (CPO-27-Co), and 1603 m2 g-1 (CPO-27-Mg). We anticipate that our method could be applied to produce CPO-27-Ni, -Mg, -Co and -Zn with STYs of 44 kg m-3 per day, 191 kg m-3 per day, 1462 kg m-3 per day and a record 18720 kg m-3 per day, respectively., This work was supported by the Spanish MINECO (project PN MAT2012-30994) and the EC (project FP7 ERC-Co 61594). I. I. acknowledges the Spanish MINECO for a Ramón y Cajal grant. ICN2 acknowledges support of the Spanish MINECO through the Severo Ochoa Centres of Excellence Program (Grant SEV-2013-0295).