High Quality Biowaxes from Fatty Acids and Fatty Esters: Catalyst and Reaction Mechanism for Accompanying Reactions

[EN] Biowaxes are interesting materials for pharmaceutical industry and consumer goods. Here the production of waxes from alternative renewable resources has been evaluated on the basis of the ketonic decarboxylation of fatty acids. The latter converts carboxylic acids (or their derivatives) into ketones with almost double chain length. Hence, sunflower oil was employed as starting material and passed over monoclinic zirconium. A wax fraction of 43% yield was obtained, though high content of molecules with more than 30 carbon atoms was not achieved due to prevalent carbon chain degradation. However, reaction of methyl stearate over zirconium oxide gave 60% wax fraction. Together with the waxes, an almost oxygen-free diesel fraction was obtained in more than 25% yield. Labeling experiments showed that the ketone intermediate is degraded by a radical chain mechanism. It is further concluded that methyl stearate radical formation is induced by carbon carbon bond scission at high temperature whereas the glycerol part of the triglyceride may act as radical initiator. As a consequence, long linear alkane waxes should be produced in the absence of glycerol (moieties). The exploitation of the side-product as high quality diesel together with the waxes improves the economic feasibility of the process.The authors thank MINECO (CTQ2015-67591-P and Severo Ochoa program, SEV-2016-0683) and Generalitat Valenciana (PROMETEO II/2013/011 Project) for funding this work. B.O.-T. is grateful to the CSIC (JAE program) for his Ph.D. fellowship.Oliver-Tomás, B.; Renz, M.; Corma Canós, A. (2017). High Quality Biowaxes from Fatty Acids and Fatty Esters: Catalyst and Reaction Mechanism for Accompanying Reactions. Industrial & Engineering Chemistry Research. 56(45):12871-12878. https://doi.org/10.1021/acs.iecr.7b01794S1287112878564

Evaluation of hydrothermal carbonization in urban mining for the recovery of phosphorus from the organic fraction of municipal solid waste

[EN] The organic fraction of municipal solid waste was identified as an alternative phosphorus resource: hydrothermal carbonization provided phosphorus-rich hydrochar. Two alternative valorization pathways can be considered for the latter: the use as a fertilizer or as solid fuel after phosphorus extraction. By means of life cycle assessment (LCA) the environmental impact of extracting phosphorus and using the hydrochar as solid fuel was evaluated. Therefore, in a first step, phosphorus extraction with nitric acid, hydrochloric acid and sulfuric acid was experimentally investigated on laboratory scale. Nitric acid proved to be the most suitable because it offered high extraction efficiency and improved solid fuel properties such as lower ash content and lower levels of chlorine and sulfur. In contrast, hydrochloric acid increased the chlorine content and sulfuric acid only replaced phosphate by sulfate, but did not reduce the ash content of hydrochar. Then phosphorus can be precipitated and used as fertilizer. Although technically feasible, LCA points out that the separate use of hydrochar and phosphorus represents an overall environmental burden for wide range of impact categories, including climate change and resource depletion. Therefore, other applications for phosphorus-rich hydrochars, like agriculture and horticulture, should be considered.The authors are grateful for the financial support received from the Spanish Ministry of Economy and Competiveness under the RTC-2015-4017-3 of the state programme "Research, Development and Innovation Oriented to the Challenges of Society"Oliver-Tomás, B.; Hitzl, M.; Owsianiak, M.; Renz, M. (2019). Evaluation of hydrothermal carbonization in urban mining for the recovery of phosphorus from the organic fraction of municipal solid waste. Resources Conservation and Recycling. 147:111-118. https://doi.org/10.1016/j.resconrec.2019.04.023S11111814

Conversion of levulinic acid derived valeric acid into a liquid transportation fuel of the kerosene type

[EN] In the transformation of lignocellulosic biomass into fuels and chemicals carbon-carbon bond formations and rising hydrophobicity are highly desired. The ketonic decarboxylation fits these requirements perfectly as it converts carboxylic acids into ketoneThe authors thank MINECO (Consolider Ingenio 2010-MULTICAT, CSD2009-00050 and CTQ2011-27550) and the Spanish National Research Council (CSIC, Es 2010RU0108). B.O.-T. is grateful to CSIC for a fellowship (JAE Programme).Corma Canós, A.; Oliver-Tomás, B.; Renz ., M.; Simakova, I. (2014). Conversion of levulinic acid derived valeric acid into a liquid transportation fuel of the kerosene type. Journal of Molecular Catalysis A Chemical. 388:116-122. https://doi.org/10.1016/j.molcata.2013.11.015S11612238

Effect of the C-alpha substitution on the ketonic decarboxylation of carboxylic acids over m-ZrO2: the role of entropy

[EN] The kinetics of the ketonic decarboxylation of linear and branched carboxylic acids over m-ZrO2 as a catalyst has been investigated. The same apparent activation energy is experimentally determined for the ketonic decarboxylation of both linear pentanoic and branched 2-methyl butanoic acids, while the change in entropy for the rate-determining step differs by nearly 50 kJ mol(-1). These results show that the difference in reactivity between linear and branched acids is due to entropic effects, and is related to the probability of finding the reactant molecules adsorbed and activated in a suitable way on the catalyst surface.The authors thank MINECO (Consolider Ingenio 2010-MULTICAT, CSD2009-00050 and Severo Ochoa program, SEV-2012-0267), Generalitat Valenciana (PROMETEOII/2013/011 Project), and the Spanish National Research Council (CSIC, Es 2010RU0108) for financial support. Red Espanola de Supercomputacion (RES) and Centre de Calcul de la Universitat de Valencia are gratefully acknowledged for computational facilities and technical assistance. A. P., F. G. and B. O.-T. thank MINECO (Juan de la Cierva and FPU Programme) and CSIC (JAE Programme) for their fellowships, respectively. M. R. is grateful to the Generalitat Valenciana for a BEST 2015 fellowship.Oliver-Tomás, B.; Gonell-Gómez, F.; Pulido, A.; Renz, M.; Boronat Zaragoza, M. (2016). Effect of the C-alpha substitution on the ketonic decarboxylation of carboxylic acids over m-ZrO2: the role of entropy. Catalysis Science and Technology. 6(14):5561-5566. https://doi.org/10.1039/c6cy00395hS55615566614Friedel, C. (1858). Ueber s. g. gemischte Acetone. Annalen der Chemie und Pharmacie, 108(1), 122-125. doi:10.1002/jlac.18581080124W. L. Howard , in Encyclopedia of Chemical Technology (Kirk-Othmer), Wiley-Interscience, New York, 4th edn, 1998, vol. 1, pp. 176–194H. Siegel and M.Eggersdorfer, Ullmann's Encyclopedia of Industrial Chemistry, VCH, Weinheim, 1990Huber, G. W., Iborra, S., & Corma, A. (2006). Synthesis of Transportation Fuels from Biomass:  Chemistry, Catalysts, and Engineering. Chemical Reviews, 106(9), 4044-4098. doi:10.1021/cr068360dCorma, A., Iborra, S., & Velty, A. (2007). Chemical Routes for the Transformation of Biomass into Chemicals. Chemical Reviews, 107(6), 2411-2502. doi:10.1021/cr050989dChheda, J. N., Huber, G. W., & Dumesic, J. A. (2007). Liquid-Phase Catalytic Processing of Biomass-Derived Oxygenated Hydrocarbons to Fuels and Chemicals. Angewandte Chemie International Edition, 46(38), 7164-7183. doi:10.1002/anie.200604274Renz, M. (2005). Ketonization of Carboxylic Acids by Decarboxylation: Mechanism and Scope. European Journal of Organic Chemistry, 2005(6), 979-988. doi:10.1002/ejoc.200400546Corma, A., Renz, M., & Schaverien, C. (2008). Coupling Fatty Acids by Ketonic Decarboxylation Using Solid Catalysts for the Direct Production of Diesel, Lubricants, and Chemicals. ChemSusChem, 1(8-9), 739-741. doi:10.1002/cssc.200800103Pham, T. N., Sooknoi, T., Crossley, S. P., & Resasco, D. E. (2013). Ketonization of Carboxylic Acids: Mechanisms, Catalysts, and Implications for Biomass Conversion. ACS Catalysis, 3(11), 2456-2473. doi:10.1021/cs400501hSerrano-Ruiz, J. C., Wang, D., & Dumesic, J. A. (2010). Catalytic upgrading of levulinic acid to 5-nonanone. Green Chemistry, 12(4), 574. doi:10.1039/b923907cAlonso, D. M., Bond, J. Q., & Dumesic, J. A. (2010). Catalytic conversion of biomass to biofuels. Green Chemistry, 12(9), 1493. doi:10.1039/c004654jCorma, A., Oliver-Tomas, B., Renz, M., & Simakova, I. L. (2014). Conversion of levulinic acid derived valeric acid into a liquid transportation fuel of the kerosene type. Journal of Molecular Catalysis A: Chemical, 388-389, 116-122. doi:10.1016/j.molcata.2013.11.015Rajadurai, S. (1994). Pathways for Carboxylic Acid Decomposition on Transition Metal Oxides. Catalysis Reviews, 36(3), 385-403. doi:10.1080/01614949408009466Gliński, M., Kijeński, J., & Jakubowski, A. (1995). Ketones from monocarboxylic acids: Catalytic ketonization over oxide systems. Applied Catalysis A: General, 128(2), 209-217. doi:10.1016/0926-860x(95)00082-8Pestman, R., Koster, R. M., van Duijne, A., Pieterse, J. A. Z., & Ponec, V. (1997). Reactions of Carboxylic Acids on Oxides. Journal of Catalysis, 168(2), 265-272. doi:10.1006/jcat.1997.1624Parida, K., & Mishra, H. K. (1999). Catalytic ketonisation of acetic acid over modified zirconia. Journal of Molecular Catalysis A: Chemical, 139(1), 73-80. doi:10.1016/s1381-1169(98)00184-8Hendren, T. S., & Dooley, K. M. (2003). Kinetics of catalyzed acid/acid and acid/aldehyde condensation reactions to non-symmetric ketones. Catalysis Today, 85(2-4), 333-351. doi:10.1016/s0920-5861(03)00399-7Martinez, R. (2004). Ketonization of acetic acid on titania-functionalized silica monoliths. Journal of Catalysis, 222(2), 404-409. doi:10.1016/j.jcat.2003.12.002Pulido, A., Oliver-Tomas, B., Renz, M., Boronat, M., & Corma, A. (2012). Ketonic Decarboxylation Reaction Mechanism: A Combined Experimental and DFT Study. ChemSusChem, 6(1), 141-151. doi:10.1002/cssc.201200419Ignatchenko, A. V., DeRaddo, J. S., Marino, V. J., & Mercado, A. (2015). Cross-selectivity in the catalytic ketonization of carboxylic acids. Applied Catalysis A: General, 498, 10-24. doi:10.1016/j.apcata.2015.03.017Ignatchenko, A. V., & Kozliak, E. I. (2012). Distinguishing Enolic and Carbonyl Components in the Mechanism of Carboxylic Acid Ketonization on Monoclinic Zirconia. ACS Catalysis, 2(8), 1555-1562. doi:10.1021/cs3002989Ignatchenko, A. V. (2011). Density Functional Theory Study of Carboxylic Acids Adsorption and Enolization on Monoclinic Zirconia Surfaces. The Journal of Physical Chemistry C, 115(32), 16012-16018. doi:10.1021/jp203381hJackson, M. A., & Cermak, S. C. (2012). Cross ketonization of Cuphea sp. oil with acetic acid over a composite oxide of Fe, Ce, and Al. Applied Catalysis A: General, 431-432, 157-163. doi:10.1016/j.apcata.2012.04.034Plint, N. ., Coville, N. ., Lack, D., Nattrass, G. ., & Vallay, T. (2001). The catalysed synthesis of symmetrical ketones from alcohols. Journal of Molecular Catalysis A: Chemical, 165(1-2), 275-281. doi:10.1016/s1381-1169(00)00445-3Randery, S. (2002). Cerium oxide-based catalysts for production of ketones by acid condensation. Applied Catalysis A: General, 226(1-2), 265-280. doi:10.1016/s0926-860x(01)00912-

Direct conversion of carboxylic acids (C-n) to alkenes (C2n-1) over titanium oxide in absence of noble metals

Carbon-carbon bond formations and deoxygenation reactions are important for biomass up-grading. The classical ketonic decarboxylation of carboxylic acids provides symmetrical ketones with 2n+1 carbon atoms and eliminates three oxygen atoms. Herein, this reaction is carried out with titanium oxide at 400 degrees C, and an olefin with 2n + 1 carbon atoms is obtained instead of the ketone. For olefin formation hydrogen transfer reactions are required from suitable precursors to form aromatics and coke. Additional aldol condensation reactions increase further molecular weight in the product mixture. Hence, a combination of titanium oxide with a hydrodeoxygenation bed provides double amount of diesel fuel as the combination with zirconium oxide when reacting hexose-derived pentanoic acid.The authors thank MINECO (MAT2011-28009, Consolider Ingenio 2010-MULTICAT, CSD2009-00050 and Severo Ochoa program, SEV-2012-0267), Generalitat Valenciana (PROMETEOII/2013/011 Project), and the Spanish National Research Council (CSIC, Es 2010RU0108). B.O.-T. is grateful to the CSIC (JAE Programme) for his Ph.D. fellowship.Oliver-Tomás, B.; Renz, M.; Corma Canós, A. (2016). Direct conversion of carboxylic acids (C-n) to alkenes (C2n-1) over titanium oxide in absence of noble metals. Journal of Molecular Catalysis A: Chemical. 415:1-8. https://doi.org/10.1016/j.molcata.2016.01.019S1841

Optimisation of post-drawing treatments by means of neutron diffraction

The mechanical properties and the durability of cold-drawn eutectoid wires (especially in aggressive environments) are influenced by the residual stresses generated during the drawing process. Steelmakers have devised procedures (thermomechanical treatments after drawing) attempting to relieve them in order to improve wire performance. In thiswork neutron diffraction measurements have been used to ascertain the role of temperature and applied force – during post-drawing treatments – on the residual stresses of five rod batches with different treatments. The results show that conventional thermomechanical treatments are successful in relieving the residual stresses created by cold-drawing, although these procedures can be improved by changing the temperature or the stretching force. Knowledge of the residual stress profiles after these changes is a useful tool to improve the thermomechanical treatments instead of the empirical procedures used currently

The improvement of Mo/4H-SiC Schottky diodes via a P2O5 surface passivation treatment

Molybdenum (Mo)/4H-silicon carbide (SiC) Schottky barrier diodes have been fabricated with a phosphorus pentoxide (P2O5) surface passivation treatment performed on the SiC surface prior to metallization. Compared to the untreated diodes, the P2O5-treated diodes were found to have a lower Schottky barrier height by 0.11 eV and a lower leakage current by two to three orders of magnitude. Physical characterization of the P2O5-treated Mo/SiC interfaces revealed that there are two primary causes for the improvement in electrical performance. First, transmission electron microscopy imaging showed that nanopits filled with silicon dioxide had formed at the surface after the P2O5 treatment that terminates potential leakage paths. Second, secondary ion mass spectroscopy revealed a high concentration of phosphorus atoms near the interface. While only a fraction of these are active, a small increase in doping at the interface is responsible for the reduction in barrier height. Comparisons were made between the P2O5 pretreatment and oxygen (O2) and nitrous oxide (N2O) pretreatments that do not form the same nanopits and do not reduce leakage current. X-ray photoelectron spectroscopy shows that SiC beneath the deposited P2O5 oxide retains a Si-rich interface unlike the N2O and O2 treatments that consume SiC and trap carbon at the interface. Finally, after annealing, the Mo/SiC interface forms almost no silicide, leaving the enhancement to the subsurface in place, explaining why the P2O5 treatment has had no effect on nickel- or titanium-SiC contacts

Early age exposure to moisture and mould is related to FeNO at the age of 6 years

Background Exposure to indoor moisture damage and visible mold has been found to be associated with asthma and respiratory symptoms in several questionnaire-based studies by self-report. We aimed to define the prospective association between the early life exposure to residential moisture damage or mold and fractional exhaled nitric oxide (FeNO) and lung function parameters as objective markers for airway inflammation and asthma in 6-year-old children. Methods Home inspections were performed in children's homes when infants were on average 5 months old. At age 6 years, data on FeNO (n = 322) as well as lung function (n = 216) measurements were collected. Logistic regression and generalized additive models were used for statistical analyses. Results Early age major moisture damage and moisture damage or mold in the child's main living areas were significantly associated with increased FeNO levels (>75th percentile) at the age of 6 years (adjusted odds ratios, 95% confidence intervals, aOR (95% CI): 3.10 (1.35-7.07) and 3.16 (1.43-6.98), respectively. Effects were more pronounced in those who did not change residential address throughout the study period. For lung function, major structural damage within the whole home was associated with reduced FEV1 and FVC, but not with FEV1/FVC. No association with lung function was observed with early moisture damage or mold in the child's main living areas. Conclusion These results underline the importance of prevention and remediation efforts of moisture and mold-damaged buildings in order to avoid harmful effects within the vulnerable phase of the infants and children's immunologic development.Peer reviewe

Arginine- but not alanine-rich carboxy-termini trigger nuclear translocation of mutant keratin 10 in ichthyosis with confetti

Ichthyosis with confetti (IWC) is a genodermatosis associated with dominant-negative variants in keratin 10 (KRT10) or keratin 1 (KRT1). These frameshift variants result in extended aberrant proteins, localized to the nucleus rather than the cytoplasm. This mislocalization is thought to occur as a result of the altered carboxy (C)-terminus, from poly-glycine to either a poly-arginine or -alanine tail. Previous studies on the type of C-terminus and subcellular localization of the respective mutant protein are divergent. In order to fully elucidate the pathomechanism of IWC, a greater understanding is critical. This study aimed to establish the consequences for localization and intermediate filament formation of altered keratin 10 (K10) C-termini. To achieve this, plasmids expressing distinct KRT10 variants were generated. Sequences encoded all possible reading frames of the K10 C-terminus as well as a nonsense variant. A keratinocyte line was transfected with these plasmids. Additionally, gene editing was utilized to introduce frameshift variants in exon 6 and exon 7 at the endogenous KRT10 locus. Cellular localization of aberrant K10 was observed via immunofluorescence using various antibodies. In each setting, immunofluorescence analysis demonstrated aberrant nuclear localization of K10 featuring an arginine-rich C-terminus. However, this was not observed with K10 featuring an alanine-rich C-terminus. Instead, the protein displayed cytoplasmic localization, consistent with wild-type and truncated forms of K10. This study demonstrates that, of the various 3' frameshift variants of KRT10, exclusively arginine-rich C-termini lead to nuclear localization of K10