Showing papers by "Vitaliy L. Budarin published in 2013"

Direct microwave-assisted hydrothermal depolymerization of cellulose.

Abstract: A systematic investigation of the interaction of microwave irradiation with microcrystalline cellulose has been carried out, covering a broad temperature range (150 → 270 °C). A variety of analytical techniques (e.g., HPLC, 13C NMR, FTIR, CHN analysis, hydrogen–deuterium exchange) allowed for the analysis of the obtained liquid and solid products. Based on these results a mechanism of cellulose interaction with microwaves is proposed. Thereby the degree of freedom of the cellulose enclosed CH2OH groups was found to be crucial. This mechanism allows for the explanation of the different experimental observations such as high efficiency of microwave treatment; the dependence of the selectivity/yield of glucose on the applied microwave density; the observed high glucose to HMF ratio; and the influence of the degree of cellulose crystallinity on the results of the hydrolysis process. The highest selectivity toward glucose was found to be ∼75% while the highest glucose yield obtained was 21%.

Torrefaction/biochar production by microwave and conventional slow pyrolysis - comparison of energy properties

Abstract: The energy efficiency of torrefaction/pyrolysis of biomass to fuel/biochar was studied using conventional (slow) and microwave (low temperature) pyrolysis. Conventional pyrolysis is approximately three times as energy efficient as microwave pyrolysis, in terms of the energy required to process a unit of feedstock. However, this is more than compensated for by the higher energy content of the condensable and gaseous coproducts from microwave pyrolysis, as these can be utilized to generate the electricity required to drive the process. It is proposed that the most efficient method of torrefaction/biochar production is a combination of conventional heating with ‘catalytic’ amount of microwave irradiation.

Microwave-enhanced formation of glucose from cellulosic waste

Abstract: The conversion of cellulose and cellulosic waste to fermentable sugars has been successfully demonstrated. Using a novel microwave intensified hydrothermal depolymerisation of cellulosic materials in liquid hot water, at pressures below 300 psi, conversions of up to 40% of fermentable sugars were obtained with limited by-product formation. A high selectivity for glucose over other sugars has been observed. Temperature is the crucial parameter as limited conversion is observed below 180 °C and optimum conversion is attained around 220 °C.

From waste to wealth using green chemistry

Abstract: The availability of chemically rich food supply chain waste (FSCW) gives it con- siderable potential as a resource for the manufacture of chemicals including materials and fuels. By applying clean chemical technologies to the extraction and conversion of molecules from FSCW, we can aim to produce genuinely green and sustainable products to help meet the legislative and consumer-oriented demands of a sustainable society. Low-temperature microwave (MW) processing is a particularly powerful technology to achieve this aim and is shown to be effective for several different high-volume, geographically diverse biomass types.

Molecular-level understanding of the carbonisation of polysaccharides.

Abstract: Understanding of both the textural and functionality changes occurring during (mesoporous) polysaccharide carbonisation at the molecular level provides a deeper insight into the whole spectrum of material properties, from chemical activity to pore shape and surface energy, which is crucial for the successful application of carbonaceous materials in adsorption, catalysis and chromatography. Obtained information will help to identify the most appropriate applications of the carbonaceous material generated during torrefaction and different types of pyrolysis processes and therefore will be important for the development of cost- and energy-efficient zero-waste biorefineries. The presented approach is informative and semi-quantitative with the potential to be extended to the formation of other biomass-derived carbonaceous materials.

Shaped mesoporous materials from fresh macroalgae

Abstract: Reproducible highly mesoporous monolithic materials (0.5–0.7 cm3 g−1, 9–15 nm) are prepared from a variety of fresh shaped abundant macroalgae using a simple green approach without the necessity for supercritical carbon dioxide (scCO2) drying. This opens up the possibility for low cost and sustainable structured materials for chromatography, catalyst supports and drug delivery systems.

Microwave assisted citrus waste biorefinery

Abstract: There is described a method of isolating one or more of pectin, d-limonene, a flavour compound, a flavonoid, a soluble monosaccharide, a decomposition product of a monosaccharide and cellulose, from citrus material wherein said method comprises the microwave assisted hydrothermal low temperature treatment of citrus material.

Simple Preparation of Novel Metal-Containing Mesoporous Starches

Abstract: Metal-containing mesoporous starches have been synthesized using a simple and efficient microwave-assisted methodology followed by metal impregnation in the porous gel network. Final materials exhibited surface areas >60 m2 g−1, being essentially mesoporous with pore sizes in the 10–15 nm range with some developed inter-particular mesoporosity. These materials characterized by several techniques including XRD, SEM, TG/DTA and DRIFTs may find promising catalytic applications due to the presence of (hydr)oxides in their composition.

Bioraffinerie de déchets d'agrumes assistée par micro-ondes

Abstract: La presente invention concerne un procede d'isolement d'un ou de plusieurs parmi la pectine, le d-limonene, un composant aromatisant, un flavonoide, un monosaccharide soluble, un produit de decomposition d'un monosaccharide et de cellulose, provenant d'une matiere premiere d'agrume, ledit procede comprenant un traitement hydrothermal a basse temperature assiste par micro-ondes d'une matiere premiere d'agrume.