Felix Garcia-Ochoa

Bio: Felix Garcia-Ochoa is an academic researcher from Complutense University of Madrid. The author has contributed to research in topics: Catalysis & Glycerol. The author has an hindex of 42, co-authored 166 publications receiving 7574 citations. Previous affiliations of Felix Garcia-Ochoa include University of Cantabria.

Route of the catalytic oxidation of phenol in aqueous phase

Abstract: Catalytic oxidation of phenol in aqueous phase over a copper catalyst supplied by Engelhard (Cu-0203T) has been studied. A reaction pathway of phenol oxidation under intermediate temperature and pressure has been proposed. Temperatures employed were 140 and 160 °C and catalyst concentration ranged from 4 to 1550 g l −1 of liquid phase. To achieve this wide interval of catalyst concentration values, two experimental set-ups were employed: a basket stirred tank reactor (BSTR), with the liquid phase in batch, and an integral fixed-bed reactor (FBR) with co-current up-flow of gas and liquid phases. The main intermediates detected in the phenol oxidation were ring compounds (hydroquinone, catechol, benzoquinone), which break to yield CO 2 and short chain acids, mainly maleic, formic, acetic and oxalic acids, and also traces of malonic, succinic and fumaric acids. Oxalic acid was also found to form a complex with the copper which oxidizes to CO 2 . The only non-oxidizable intermediate under the conditions sets was acetic acid. In order to propose a phenol oxidation pathway, several runs were carried out where the main intermediates detected in the phenol oxidation were fed to the FBR under different temperatures and catalyst loadings. It was found that catechol oxidation does not yield either benzoquinone or maleic acid but oxalic acid which finally mineralized to CO 2 . However, benzoquinone and maleic acid are products clearly detected in the hydroquinone oxidation. Oxidation reactions of phenol and those intermediates studied take place not only on the solid surface but also in the liquid phase.

Oxidation of hardwood kraft-lignin to phenolic derivatives with oxygen as oxidant

Abstract: A hardwood kraft lignin was oxidized in alkaline medium to obtain phenolic compounds (syringaldehyde, vanillin and its acids). To avoid lignin condensation, the lignin was precipitated from a black liquor with a calcium salt dissolved in a water soluble alcohol. Oxygen was the oxidant employed, and copper (II) and cobalt (II) salts were used as catalysts. Effect of temperature, reaction time, oxygen pressure, alkali concentration and catalyst on yield and product distribution were studied. In all the range of variables lignin conversion and aldehyde yield remains low and the more important effect on aldehyde yield was due to the alkali concentration, which must be fixed at about 2 N. The precipitation method did not significantly increase the aldehyde yield, in contrast with the results of nitrobenzene and CuO oxidations. In catalyzed oxidations, no increase in phenolic aldehydes was observed and, with some catalyst, the conversion into phenolic derivatives was reduced. Lignin conversion into low molecular weight products is responsible for the low phenolic product yield and the type of catalyst could lead the oxidation into phenolic products or into low molecular weight acids.

The Catalytic Valorization of Lignin for the Production of Renewable Chemicals

Abstract: Biomass is an important feedstock for the renewable production of fuels, chemicals, and energy. As of 2005, over 3% of the total energy consumption in the United States was supplied by biomass, and it recently surpassed hydroelectric energy as the largest domestic source of renewable energy. Similarly, the European Union received 66.1% of its renewable energy from biomass, which thus surpassed the total combined contribution from hydropower, wind power, geothermal energy, and solar power. In addition to energy, the production of chemicals from biomass is also essential; indeed, the only renewable source of liquid transportation fuels is currently obtained from biomass.

Catalytic Transformation of Lignin for the Production of Chemicals and Fuels

Abstract: and Fuels Changzhi Li,† Xiaochen Zhao,† Aiqin Wang,† George W. Huber,†,‡ and Tao Zhang*,† †State Key Laborotary of Catalysis, iChEM (Collaborative Innovation Center of Chemistry for Energy Materials), Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China ‡Department of Chemical and Biological Engineering, University of WisconsinMadison, Madison, Wisconsin 53706, United States

Chemicals from lignin: an interplay of lignocellulose fractionation, depolymerisation, and upgrading

Abstract: In pursuit of more sustainable and competitive biorefineries, the effective valorisation of lignin is key. An alluring opportunity is the exploitation of lignin as a resource for chemicals. Three technological biorefinery aspects will determine the realisation of a successful lignin-to-chemicals valorisation chain, namely (i) lignocellulose fractionation, (ii) lignin depolymerisation, and (iii) upgrading towards targeted chemicals. This review provides a summary and perspective of the extensive research that has been devoted to each of these three interconnected biorefinery aspects, ranging from industrially well-established techniques to the latest cutting edge innovations. To navigate the reader through the overwhelming collection of literature on each topic, distinct strategies/topics were delineated and summarised in comprehensive overview figures. Upon closer inspection, conceptual principles arise that rationalise the success of certain methodologies, and more importantly, can guide future research to further expand the portfolio of promising technologies. When targeting chemicals, a key objective during the fractionation and depolymerisation stage is to minimise lignin condensation (i.e. formation of resistive carbon–carbon linkages). During fractionation, this can be achieved by either (i) preserving the (native) lignin structure or (ii) by tolerating depolymerisation of the lignin polymer but preventing condensation through chemical quenching or physical removal of reactive intermediates. The latter strategy is also commonly applied in the lignin depolymerisation stage, while an alternative approach is to augment the relative rate of depolymerisation vs. condensation by enhancing the reactivity of the lignin structure towards depolymerisation. Finally, because depolymerised lignins often consist of a complex mixture of various compounds, upgrading of the raw product mixture through convergent transformations embodies a promising approach to decrease the complexity. This particular upgrading approach is termed funneling, and includes both chemocatalytic and biological strategies.