A wide range of organic substances, potentially derived from biomass, were tested as reductants for CO2 (added in form of sodium bicarbonate) in hydrothermal media. The reactions were carried out in batch reactors at 300 ºC and 3h. All the substances reduced CO2 to formic acid in yields up to 65%. These results agree to […]
Category: Paper
NEW RESEARCH ARTICLE: Determination of Density and Viscosity of Binary Mixtures of Water and Dimethyl Sulfoxide with 1-Ethyl-3-methylimidazolium Diethylphosphate [EtMeIm]+[Et2PO4]− at Atmospheric Pressure
[:en]In the past few years, the global interest in the use of environmentally sustainable resources has increased. Therefore, the biopolymers, and more specifically cellulose, have received most of the attention in the search for new natural, biodegradable, and renewable resources. However, cellulose, due to its complex structure, is not easily processed because it is not […]
NEW RESEARCH ARTICLE: Applications of supercritical technologies to CO2 reduction: Catalyst development and process intensification
[:en]Our economy relies on fossil fuels that can be converted into energy and chemicals, but this model is endangered by depletion of resources and environmental problems. To solve this dilemma, we can find inspiration in photosynthetic organisms that consider CO2 as a carbon source and not as waste. CO2 utilization processes have experienced a considerable […]
NEW RESEARCH ARTICLE. PRETREATMENT EFFECT ON THE THERMAL DEGRADATION OF A FEEDSTOCK WITH LOW HEMICELLULOSE CONTENT: BRAZILIAN GINSENG
[:en]Pyrolysis is a well-known process for biomass upgrading, and a great deal of works are available about it. However, they focus on conventional lignocellulosic samples, and the information about any other less common samples, while still valuable, is very difficult to find. For instance, Brazilian ginseng (Pfaffia glomerata) is a feedstock without hemicellulose and a […]
NEW REVIEW: Understanding biomass fractionation in subcritical&supercritical water
[:en]Biomass fractionation into its individual building blocks poses a major challenge to the biorefinery concept. The recalcitrance of the lignocellulose matrix and the high crystallinity of cellulose make typical feed stocks difficult to separate into their components. Hydrothermal processing fractionates biomass by its hydrolysis. However, a deep knowledge of hydrolysis principles is required since an […]
NEW RESEARCH ARTICLE: Microwave pretreatment to improve extraction efficiency and polyphenol extract richness. Effect on antioxidant bioactivity
Microwave assisted extraction advantages are widely recognised. However, its implementation at an industrial scale is restricted due to microwave limitations. In this work, a microwave pretreatment is proposed as an easy scale-up alternative. The double effect of this pretreatment on extraction yield and on product richness is assessed. Microwaves accelerate the extraction kinetics of most […]
[Paper]: Extraction of arabinoxylans from wheat bran using hydrothermal processes assisted by heterogeneous catalysts
The extraction/hydrolysis process of arabinoxylans from destarched wheat bran was studied in this work using different mesoporous silica supports and the corresponding RuCl3-based catalysts. The effects of temperature, time, catalyst supports and ruthenium catalysts were investigated and discussed in terms of the arabinoxylans extraction yield and their polymerization degree. Relatively high temperatures (180 ºC), short […]
[Paper]: Microwave-assisted extraction of polyphenols from Clinacanthus nutans Lindau medicinal plant: Energy perspective and kinetics modelling
Microwave-assisted extraction (MAE) of polyphenols from medicinal plant, Clinacanthus nutans (C.nutans) was developed. Affecting parameters on the extraction yield of polyphenols such as ethanol concentration, solvent-to-feed ratio (S/F) and energy absorbed were studied. The variations in the effect of ethanol concentration and S/F were also explained in view of energy absorption. Polyphenols yield was found […]
[Paper]: Bimetallic Ru:Ni/MCM-48 catalysts for the effective hydrogenation of D – glucose into sorbitol
Three different bimetallic Ru:Ni catalysts supported on a mesoporous silica MCM-48 were prepared by consecutive wet impregnations, with a total metal loading of ca. 3 % (w·w-1). Ru:Ni ratios spanned in the range of 0.15 – 1.39 (w·w-1) and were compared with the corresponding monometallic Ni/MCM-48. The catalysts so prepared were characterized by X-Ray Diffraction, […]
[Paper]: Hydrothermal fractionation of grape seeds in subcritical water to produce oil extract, sugars and lignin
The fractionation of grape seeds as a model biomass was studied using a combination of two processes: solvothermal extraction using ethanol and hydrothermal fractionation-autohydrolysis process in a semicontinuous reactor using subcritial water. Around 70% of the polyphenols were extracted in the first step and close to 80% of the sugars in the second step.
