17 research outputs found
Electro-oxidative depolymerisation of technical lignin in water using platinum, nickel oxide hydroxide and graphite electrodes
In order to improve the lignin exploitation to added-value bioproducts, a mild chemical conversion route based on electrochemistry was investigated. For the first time, soda lignin Protobind™ 1000 (technical lignin from the pulp & paper industry) was studied by cyclic voltammetry to preliminarily investigate the effect of the main reaction parameters, such as the type of electrode material (platinum, nickel oxide hydroxide, graphite), the pH (12, 13, 14), the scan rate (10, 50, 100, 250 mV s-1), the substrate concentration (2, 20 g L-1) and the oxidation/reduction potential (from -0.8 to +0.8 V). Under the optimal reaction conditions among those tested (NiOOH electrode, pH 14, lignin 20 g L-1, 0.4 V), the electro-oxidative depolymerisation of lignin by electrolysis was performed in a divided cell. The reaction products were identified and quantified by ultra-pressure liquid chromatography coupled with mass spectrometry. The main products were sinapic acid, vanillin, vanillic acid, and acetovanillone. The obtained preliminary results demonstrated the potential feasibility of this innovative electrochemical route for lignin valorisation for the production of bio-aromatic chemicals
Процессы низкотемпературной дипольной релаксации в системах бычий сывороточный альбумин–нанооксид–вода
Методом термостимулированной деполяризации проведены сравнительные исследования процессов низкотемпературной дипольной релаксации в замороженных водных дисперсиях нанооксидов, индивидуальных и в присутствии бычьего сывороточного альбумина (БСА). Для последних систем характерно увеличение вкладов релаксационных процессов при Т > 160–170 К, в то время как для водных дисперсий оксидов бóльшие токи ТСД наблюдаются при Т 160…170 К, в той час як для водних дисперсій оксидів більші струми ТСД спостерігаються при Т 160- 170 К, since for aqueous suspensions of nanooxides, greater TSD currents are observed at Т < 160-170 К. This difference is due to the participation of the BSA molecules (polar bonds, groups, fragments, whole molecules) in the relaxation processes, whose features depend also on the nature of nanooxide and a character of BSA interactions with its surface
Recovery of galium and indium from liquid crystal displays and CIGS photovailtaic modules
Abstract: The increasing amount of electronics, such as consumer products and green technologies (e.g. solar PV cells) increases the demand of metals such as indium and gallium. This increasing demand together with the dependency on import of these metals drive research on recycling of waste electronics from secondary sources, so called urban mining. A hydrometallurgical process for the recovery of indium and gallium from flat panel displays and photovoltaic panels is under development within the RECLAIM project. Characterisation of flat panel displays and photovoltaic cell has been performed and has been compared with manual and automatic disassemblement. Results indicate that mineral acids can be used to release indium and gallium. Preliminary results of recovery and purification processes are presented and further research regarding these processes is outlined
Meteorological impact assessment of possible large scale irrigation in Southwest Saudi Arabia
On continental to regional scales feedbacks between landuse and landcover change and climate have been widely documented over the past 10¿15 years. In the present study we explore the possibility that also vegetation changes over much smaller areas may affect local precipitation regimes. Large scale ( 105 ha) irrigated plantations in semi-arid environments under particular conditions may affect local circulations and induce additional rainfall. Capturing this rainfall `surplus¿ could then reduce the need for external irrigation sources and eventually lead to self-sustained water cycling. This concept is studied in the coastal plains in South West Saudi Arabia where the mountains of the Asir region exhibit the highest rainfall of the peninsula due to orographic lifting and condensation of moisture imported with the Indian Ocean monsoon and with disturbances from the Mediterranean Sea. We use a regional atmospheric modeling system (RAMS) forced by ECMWF analysis data to resolve the effect of complex surface conditions in high resolution (¿x = 4 km). After validation, these simulations are analysed with a focus on the role of local processes (sea breezes, orographic lifting and the formation of fog in the coastal mountains) in generating rainfall, and on how these will be affected by large scale irrigated plantations in the coastal desert. The validation showed that the model simulates the regional and local weather reasonably well. The simulations exhibit a slightly larger diurnal temperature range than those captured by the observations, but seem to capture daily sea-breeze phenomena well. Monthly rainfall is well reproduced at coarse resolutions, but appears more localized at high resolutions. The hypothetical irrigated plantation (3.25 105 ha) has significant effects on atmospheric moisture, but due to weakened sea breezes this leads to limited increases of rainfall. In terms of recycling of irrigation gifts the rainfall enhancement in this particular setting is rather insignificant
Initializing a regional climate model with satellite-derived soil moisture
Regional climate simulations over Europe were initialized with soil moisture derived from the Advanced Microwave Scanning Radiometer-Earth Observing System (AMSR-E) in order to assess the model accuracy in predicting soil moisture and other components of the hydrological cycle. The AMSR-E soil moisture initially showed systematic differences with model-predicted soil moisture. For proper initialization the AMSR-E product had to be rescaled and after that vertically profiled. To retrieve a root zone soil moisture profile, we tested the application of an exponential filter. The smoothing through the layers of the ERA-Interim soil moisture profile was applied to the rescaled AMSR-E surface soil moisture. The filter performed very well for that part of the data set where the top layer is positively correlated with the deeper layers. After the preparation of the soil moisture fields, several sensitivity simulations were performed. The model's soil moisture was replaced with the vertically profiled AMSR-E soil moisture at different initial times for a dry summer (2003) and a wet summer (2005). In general, the surplus of soil moisture in the AMSR-E data resulted in a better performance in predicting temperature when compared with observations. This finding was more pronounced in the dry summer of 2003 when the model results appeared very sensitive to land-atmosphere feedbacks. Our results suggest that in dry years, the use of appropriate observed soil moisture may help more to reduce modeled surface temperatures than inducing additional rainfall in the model. Using the AMSR-E product led to a decrease in areal extent sensitive to land-atmosphere interactions. Copyright 2011 by the American Geophysical Union
Continuous electrochemical oxidation of biomass derived 5-(hydroxymethyl)furfural into 2,5-furandicarboxylic acid
Abstract: A continuous electrochemical process with integrated product separation has been developed for production of 2,5-furandicarboxylic acid (FDCA) by oxidation of 5-(hydroxymethyl)furfural (HMF) in aqueous alkaline media on non-noble Ni/NiOOH foam electrodes at ambient conditions. Initially, voltammetry studies were performed in both, acid and alkaline media, on various catalyst materials: Au, Au3Pd2, Pt, PbO2, Ni/NiOOH and graphite. Preparative electrolysis was performed on Au, Au3Pd2, Pt, PbO2, Ni/NiOOH electrodes in a divided glass cell and Ni/NiOOH showed the best performance with an FDCA yield of ≈ 90% and a Faradaic efficiency of ≈ 80%. The electrolysis conditions were then optimized to industrially relevant conditions in a filter-press type flow reactor with Ni/NiOOH foam anode. HMF concentrations as high as 10 wt% were converted to FDCA at pH 12 in a buffer free 0.1 M Na2SO4 electrolyte with continuous addition of NaOH to maintain constant pH. An FDCA separation yield up to 95% was achieved via pH shift crystallization. The electrolysis and FDCA separation results were used for the design and construction of a bench-scale system where continuous FDCA production, including integrated product separation, was tested and reported in this work. This publication for the first time presents a continuous electrochemical FDCA production system with integrated product separation at industrially relevant product concentrations, 10 wt% HMF, and utilizing non-noble electrode materials. Graphical Abstract: [Figure not available: see fulltext.
Identification and typing of Brucella spp. in stranded harbour porpoises (Phocoena phocoena) on the Dutch coast.
The presence of Brucella (B.) spp. in harbour porpoises stranded between 2008 and 2011 along the Dutch coast was studied. A selection of 265 tissue samples from 112 animals was analysed using conventional and molecular methods. In total, 4.5% (5/112) of the animals corresponding with 2.3% (6/265) Brucella positive tissue samples were Brucella positive by culture and these were all confirmed by real-time polymerase chain reaction (real-time PCR) based on the insertion element 711 (IS711). In addition, two more Brucella-positive tissue samples from two animals collected in 2011 were identified using real-time PCR resulting in an overall Brucella prevalence of 6.3% (7/112 animals). Brucella spp. were obtained from lungs (n=3), pulmonary lymph node (n=3) and lungworms (n=2). Multi Locus Variable Number of Tandem Repeats (VNTR) Analysis (MLVA) typing based on the MLVA-16 showed that the Brucella isolates were B. ceti. Additional in silico Multi Locus Sequence typing (MLST) after whole genome sequencing of the 6 Brucella isolates confirmed B. ceti ST 23. According to the Brucella 2010 MLVA database, the isolated Brucella strains encountered were of five genotypes, in two distinct subclusters divided in two different time periods of harbour porpoises collection. This study is the first population based analyses for Brucella spp. infections in cetaceans stranded along the Dutch coast