Search

Biomass can be considered as a potential resource for the production of renewable fuels. Lignocellulose biomass is a widely available, renewable, biodegradable, and biocompatible resource that can potentially reduce the dependence of modern society on fossil resources. It is a potential feedstock for the production of heat, electricity, fuel, chemicals, and other bioderived products. Considerable attention of researchers is directed to the conversion of biomass into bioenergy through chemical, biochemical, or thermochemical processes. Hydrolysis is considered to be one of the important steps to convert biomass into valuable chemicals. During hydrolysis, liquid rich in sugars with a certain amount of dissolved lignin, usually called hydrolysate, is formed. In this paper, the influence of the catalyst type, temperature, catalyst concentration, and solvent type on the conversion and composition of hydrolysate was studied. The highest yield of hydrolysis products (hexoses and pentoses) reached up to 80 wt. % at a temperature of 220 °C in water medium in the presence of 1.5 wt. % of sulfuric acid.

The integration of biofuel upgrading processes in the existing technologies of crude oil refining is considered to be one of the promising directions for the production of liquid motor fuels. In this work, the co-processing of bio-oil obtained from biomass waste and heavy oil fractions in the supercritical solvent was studied. The bio-oil was obtained by the slow pyrolysis of birch and pine wood sawdust in the presence of a Fe-containing zeolite-based catalyst. The influence of the catalyst on the yield and composition of liquid products was studied. To find the optimal reaction conditions, the co-processing of the model compounds (anisole – eicosane – dibenzothiophene) was carried out by varying the solvent, reaction temperature, and the initial nitrogen pressure. Full removal of oxygen and sulfur as well as a decrease in the concentration of heavy and polyaromatic compounds from the feedstock were observed under the following process parameters: solvent – propanol-2, reaction temperature – 260 °C, initial nitrogen pressure – 1.5 MPa, total pressure – 7.2 MPa.

In this work, for the first time, naphthalene (NA)-based polymers were synthesized by one-stage Friedel–Crafts crosslinking. The influence of NA functionalization by -OH, -SO3H, and -NO2 groups on the polymers’ porosity and distribution of the catalytically active phase (Pd) was studied. Synthesized catalytic systems containing 1 wt.% of Pd either in the form of Pd(II) species or Pd(0) nanoparticles supported on NA-based polymers were tested in a model reaction of Suzuki cross-coupling between 4-bromoanisole and phenylboronic acid under mild reaction conditions (60 °C, ethanol-water mixture as a solvent). These novel catalysts demonstrated high efficiency with more than 95% of 4-bromoanisole conversion and high selectivity (>97%) for the target 4-methoxybiphenyl.

Nowadays, the processes for the conversion of biomass to fuels are of great interest. One of the widely studied reactions is the deoxygenation of oxygen-containing compounds. The process is performed in two main directions: in hydrogen presence (namely hydrodeoxygenation) and using supercritical fluids as a hydrogen source. The modern problem in deoxygenation is catalyst stability and selectivity. Thus, the development of novel catalytic systems is an urgent task. Schungite is a natural carbon-reach material that has high sorption ability and excellent reductive properties. These properties make this material suitable for its use as catalyst support. In this work, the study of the effectiveness of novel schungite-based catalysts in supercritical deoxygenation of fatty acids and bio-oil model compounds is presented. The catalyst synthesis was performed by the recently developed method of Ni hydrothermal deposition on the schungite surface. The synthesized catalysts were tested in the deoxygenation of stearic acid and guayacol in the supercritical hexane. The experimental results showed that the developed catalysts allow 100 % conversion of the substrate to be reached in both processes providing over 90 wt.% of gasoline and diesel-range hydrocarbon yield.

The search of the novel stable and active catalysts for the Fischer-Tropsch synthesis aimed at the formation of gasoline-range hydrocarbons is one of the main directions for the production of liquid transportation fuels from the alternative feedstock. The stabilization of the active phase is one of the key challenges for the development of the catalysts of CO hydrogenation into liquid motor fuel. This problem can be solved by the choice of optimal support as well as the method of synthesis. The rigid polymeric matrices allow obtaining highly effective and stable metal-containing nanoparticles characterized by the high surface area and enhanced activity. A hydrothermal deposition is a promising way to produce catalysts with the high dispersion of the active phase avoiding the pore blockage by the metal-containing particles. The current work is devoted to the development of novel polymer-based mono- and bimetallic Co-, Ni-, and Ru-containing nanocatalysts for the liquid-phase Fischer-Tropsch synthesis. It was shown that 1 % Ru-HPS and 10 % Co-1 % Ru-HPS allow obtaining a high yield of gasoline-range C5-C9 hydrocarbons (over 70 %) providing high CO conversion (up to 23 %). The chosen polymer-based systems showed high stability in the FTS process. The activity loss was found to be insignificant for both catalysts (3.2 % for 1 % Ru-HPS, and 8.2 % for 10 % Co-1 % Ru-HPS) after 20 h of the process.