Arsenic phytoextraction by Pteris vittata L. in line with frond conversion by solvolysis for restoring healthy crop production

International audienc

Single-step synthesis of well-crystallized and pure barium titanate nanoparticles in supercritical fluids

Single-step synthesis of ultra-fine barium titanate powder with a crystallinity as high as 90% and without barium carbonate contamination has been successfully performed under supercritical conditions using a continuous-flow reactor in the temperature range 150–380 °C at 16 MPa. To synthesize this bimetallic oxide, alkoxides, ethanol and water were used. The influence of the synthesis parameters on the BaTiO3 powder characteristics was investigated. The results show that the water to alkoxide precursor ratio, the reactor temperature and the Ba:Ti molar ratio of alkoxide precursor play a major role in the crystallization of pure and well-crystallized BaTiO3 nanoparticles. The continuous mode of operation without post-treatments for powder washing, drying or crystallization increase the industrial interest

Gasification study of winery waste using a hydrothermal diamond anvil cell

Nowadays, numerous projects are focussed on finding non-polluting energy sources. Interest in the use of biomass for energy purposes has been also revived in this context. Among others, agricultural biomass waste is one of the most promising resources. Its conversion into biofuel for further application via combustion increases its economic interest despite the initial low calorific value. In the present study, the conversion process is carried out in supercritical water (SCW), thus improving significantly the energy balance by eliminating the need for drying the biomass. The SCW dissolution, hydrolysis and oxidation of pure substances in a hydrothermal diamond anvil cell (HDAC) have been studied previously and unique results concerning the homogeneous dissolution of naphthalene, cellulose and glucose were acquired. The current investigation was performed for samples representing real biomass (winery residues) rather than pure substances. Visualizations of the SCW biomass gasification process were obtained and the products of the decomposition were also analyzed. It is expected that this work will contribute in valorizing winery waste by decreasing the cost required for its elimination and will also contribute significantly to green house gases mitigation

Supercritical water biomass gasification process as a successful solution to valorize wine distillery wastewaters

The biomass is the whole organic matter of vegetable or animal origin. This material can be valorized in various ways: it can be used by manufacturers (lumber, paper, and biochemistry); it can be used as energy (heat, electricity, and fuel); and it can be used as food or in cosmetics. Various processes are nowadays used to valorize biomass. This work deals with the potentialities of the biomass gasification in supercritical water. The objective is to demonstrate the potentiality of this process to treat some aqueous waste from distillery to obtain a syngas with a high hydrogen yield. The bioresources of this study come from some agricultural alcohol (beet, sugar cane, and cereal) and wine-producing distilleries. Experiments have been carried out at different conversion severities, using a 100 mL batch reactor, during 0-60 min, at a pressure of 25 MPa and at temperatures between 400 and 500 °C. Complete product analyses will be presented. Particularly detailed gas analyses have been performed. The sodium and potassium behaviors during the process have been accurately studied as a function of the substrate. Correlations between the experimental operating conditions and these analyses will be discussed in order to determine optimal experimental conditions to gasify this specific biomass

Environmental feasibility of the recycling of carbon fibers from CRFRPs by solvolysis using supercritical water

Originally developed for high-tech applications in the aeronautic and aerospace industry, carbon/epoxy composites have been increasingly used in the automotive, leisure, and sports industries for several years. Nevertheless, the carbon reinforcement is an expensive constituent, and it has been recently shown that it is also the most environmentally impacting in a composite part manufacturing. Recycling these materials (even restricted to the reinforcement recovery) could lead to economic and environmental benefits, while satisfying legislative end-of-life requirements. The solvolysis of the matrix by water under supercritical conditions is an efficient solution to recover the carbon fiber reinforcement with mechanical properties closed to the ones of virgin fibers. This paper aims at demonstrating the environmental feasibility of the recycling of carbon fiber/thermoset matrix composites by solvolysis of the matrix in supercritical water. This demonstration is based on life cycle assessment that evaluates benefits and environmental challenges of this recycling loop

Crop rotation of tobacco and sunflower on Cu-contaminated land: Cu phytoextraction, ecological restoration of ecosystem services, and biomass production for conversion technologies in line with the Bio-Economy

International audienc

Development of Sulfonated Catalysts Based on Graphite-Like Carbon Sibunit for Cellulose Hydrolysis

Твердые кислотные катализаторы, предназначенные для переработки целлюлозы в востребованные химические соединения (глюкозу и 5-гидроксиметилфурфурол) в водной среде, готовили на основе графитоподобного углеродного материала «Сибунит-4» методом сульфирования дымящейся серной кислотой при различных температурах с последующей обработкой в воде при 180 ºС. Катализаторы исследованы методами низкотемпературной адсорбции азота, кислотно-основного титрования. Изучение активности катализаторов в процессе гидролиза механически активированной микрокристаллической целлюлозы проводили при 180 °С и 1 МРа в инертной атмосфере. Основными продуктами процесса являются глюкоза и 5-гидроксиметилфурфурол с максимальными выходами до 46 и 22 %. Сравнение результатов исследования активности и устойчивости катализаторов показало, что наиболее перспективным является катализатор, сульфированный при 200 °СSolid acidic catalysts for the processing of cellulose in the value-added chemical (glucose and 5-hydroxymethylfurfural) in aqueous media ware prepared on the basis of graphite-like carbon «Sibunit - 4» using sulfonation by sulfuric acid at different temperatures, followed by treatment in water at 180 ºC. Prepared catalysts were characterized by low-temperature nitrogen adsorption and acid-base titration. Testing of catalytic activity in the hydrolysis of the mechanically activated microcrystalline cellulose was carried out at 180 ° C and 1 MPa of argon. The main products of the process are glucose and 5-hydroxymethylfurfural with yields up to 46 and 22 mol. %. Comparison of the results of the activity and stability of catalysts showed that the most promising is the catalyst sulfated at 200 °

Development of Sulfonated Catalysts Based on Graphite-Like Carbon Sibunit for Cellulose Hydrolysis

Твердые кислотные катализаторы, предназначенные для переработки целлюлозы в востребованные химические соединения (глюкозу и 5-гидроксиметилфурфурол) в водной среде, готовили на основе графитоподобного углеродного материала «Сибунит-4» методом сульфирования дымящейся серной кислотой при различных температурах с последующей обработкой в воде при 180 ºС. Катализаторы исследованы методами низкотемпературной адсорбции азота, кислотно-основного титрования. Изучение активности катализаторов в процессе гидролиза механически активированной микрокристаллической целлюлозы проводили при 180 °С и 1 МРа в инертной атмосфере. Основными продуктами процесса являются глюкоза и 5-гидроксиметилфурфурол с максимальными выходами до 46 и 22 %. Сравнение результатов исследования активности и устойчивости катализаторов показало, что наиболее перспективным является катализатор, сульфированный при 200 °СSolid acidic catalysts for the processing of cellulose in the value-added chemical (glucose and 5-hydroxymethylfurfural) in aqueous media ware prepared on the basis of graphite-like carbon «Sibunit - 4» using sulfonation by sulfuric acid at different temperatures, followed by treatment in water at 180 ºC. Prepared catalysts were characterized by low-temperature nitrogen adsorption and acid-base titration. Testing of catalytic activity in the hydrolysis of the mechanically activated microcrystalline cellulose was carried out at 180 ° C and 1 MPa of argon. The main products of the process are glucose and 5-hydroxymethylfurfural with yields up to 46 and 22 mol. %. Comparison of the results of the activity and stability of catalysts showed that the most promising is the catalyst sulfated at 200 °