Browsing by Keyword "Green chemistry"
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Item Electrosynthesis of 2,3-butanediol and methyl ethyl ketone from acetoin in flow cells(2019) Ochoa-Gómez, José R.; Fernández-Carretero, Francisco; Río-Pérez, Francisca; García-Luis, Alberto; Roncal, Tomás; García-Suárez, Eduardo J.; Tecnalia Research & Innovation; TECNOLOGÍAS DE HIDRÓGENO; BIOECONOMÍA Y CO2Acetoin could shortly become a platform molecule due to current progress in fermentation technology, the megatrend for shifting from an oil-based economy to one based on biomass, the quest for green manufacturing processes and its two highly reactive carbonyl and hydroxyl moieties. In this paper, the successful electro-conversion of acetoin into two valuable chemicals, 2,3-butandiol (2,3-BD) and methyl ethyl ketone (MEK), at constant electrical current in aqueous phase at room temperature using both divided and undivided 20 cm2 filter-press flow cells under experimental conditions suitable for industrial production is reported. Cathode material is the key parameter to drive the electroreduction towards one or another chemical. 2,3-BD is the major chemical produced by electrohydrogenation when low hydrogen overvoltage cathodes, such as Pt and Ni, of high surface area obtained by PVD coating on a carbon gas diffusion layer are used, while MEK is the principal product produced by electrohydrogenolysis when high hydrogen overvoltage cathodes, such as graphite, Pb and Cd foils, are employed. 2,3-BD and MEK can be obtained, respectively, in 92.8% and 85.7% selectivities, 71.7% and 80.4% current efficiencies, with 1.21 and 1.08 kg.h-1.m-2 productivities and power consumptions of 2.94 and 4.1 kWh.kg-1 using undivided cells and aqueous K2HPO4 electrolysis media at pHs of 3.6 and 5.5. The reported electroconversion of acetoin is highly flexible because 2,3-BD and MEK can be produced by changing just the cathode but using the same cell, with the same electrolyte at the same current density.Item LCA case study: comparison between independent and coproduction pathways for the production of ethyl and n-butyl acetates(2018-02-01) Bories, Cecile; Guzman Barrera, Nydia Ileana; Peydecastaing, Jerome; Etxeberria, Idoia; Vedrenne, Emeline; Garcia, Carlos Vaca; Thiebaud-Roux, Sophie; Sablayrolles, Caroline; BIOECONOMÍA Y CO2Purpose: The production of ethyl acetate and n-butyl acetate was investigated through two different pathways: either by independent reactions or by coproduction. In the coproduction pathway, the n-butyl acetate was produced by reusing the by-products of the synthesis of ethyl acetate. This study provides a comparison of the environmental impacts of these two pathways using a life cycle assessment (LCA). A discussion about the use of LCA on chemicals and its challenges was also developed. Methods: Ethyl acetate and n-butyl acetate were synthesized with maximum respect to the principles of green chemistry (use of heterogeneous catalyst, energy savings, minimum steps). An innovative pathway was developed to avoid waste production, by reusing all the by-products of syntheses. After characterizing the feasibility of using these solvents in paint formulations, their potential impacts on the environment were evaluated through a cradle to gate analysis, up to the synthesis at laboratory scale. Most of the foreground data were directly collected with experimental trials. The background data that were not available in the Ecoinvent 3.1 database were estimated thanks to literature or proxys. Evaluations were then performed on the SimaPro 8.1.1 LCA software, using a derivative of ILCD 2011 1.05 as life cycle impact assessment methodology. Results and discussion: The coproduction of both acetates led to the synthesis of purified ethyl acetate (purity of 92.1% w/w) and n-butyl acetate (purity of 97.1% w/w), after distillation. These results were quite similar to those obtained when independent syntheses were carried out. On an environmental point of view, it was found that the reagents preparation was always the step of the process responsible of the majority of the environmental impacts. The comparison between independent syntheses and coproduction showed that recycling the acetic acid produced during the first esterification (ethyl acetate from ethanol and acetic anhydride) led to a decrease of the impacts from 5 to 23% for all the impact categories. Conclusions: This innovative coproduction of ethyl and n-butyl acetates led to interesting results from both a technical and environmental perspective, with a clear reduction of the environmental impacts. In a context of sustainable chemistry, this appears to be a very interesting way of production. Concerning the LCA of chemicals, a lot of work is still needed in order to improve the accuracy and the reliability of the assessment.