Home – Home – Jornals – Chemistry for Sustainable Development 2011 number 2

Processes of carbon dioxide extraction from biogas by means of sorption using the inorganic residue from the integrated processing of organics-containing wastes (IPOW) as a sorbent were studied. Advantages of the IPOW process and sorption method are demonstrated, the kinetics of carbon dioxide adsorption on the inorganic residue from IPOW was investigated. It was established that the sorption on the inorganic residue is comparable in its capacities with adsorption on activated carbon. Approximate estimation of the volumes of adsorbers for IPOW set-up with the productivity of 500 t/y with respect to biogas was made. A complete scheme of the IPOW set-up including the unit of the sorption separation of biogas is presented.

Thermally reversible polymeric gel forming systems based on polymer solutions with the lower critical temperature of dissolution – cellulose ethers – were developed to increase the oil recovery from highly heterogeneous strata. The reversible phase transition solution–gel occurs due to the thermal energy of a stratum or injected heat transfer agent. Temperature and time of gelatinization can be controlled by adding electrolytes and non-electrolytes. Laboratory studies of the gelatinization kinetics, rheological and filtration characteristics in the system cellulose ethers–aqueous phase–oil are presented. Results of experimental-industrial tests of the technologies of oil recovery enhancement involving thermally reversible polymeric gels for limitation of water inflow, increase in stratum coverage degree during flooding and thermal steam formation treatment are presented. Technologies are economically profitable and ecologically safe; the pay-back period is 5–9 months. The products of large-scale industrial production are used as reagents.

Methods for obtaining biodegradable films based on protein-carbohydrate components by varying their content and establishing optimal physical and mechanical characteristics depending on the ratio of protein components were developed. The resulting films possess integral structure, strength and ability to biodegradation under natural environmental conditions. Singularity of the obtained copolymer films consists in the fact that their destruction leads to the formation of ecologically safe products being a mixture of carbohydrates and amino acids.

Data are presented concerning the macro- and microcomponent composition of the salt lakes of the North-West Mongolia. The evaluation of Li, U-238, B, Br, Sr, Rb content was performed for several lakes of the North-West Mongolia. It was demonstrated that the concentration of U-238 in lake waters can reach 1 mg/L, Li – 50 mg/L, Br – 460 mg/L, B – 100 mg/L. By the example of the Shaazgay Nuur Lake we estimated a daily intake of macro- and microcomponents at the expense of water flowing into the Hargayn Gol River. It was demonstrated that the complex processing of hydromineral raw from the lakes of the North-West Mongolia requires for purifying them from uranium.

Effect of presowing seed treatment and leaf-treatment of plants with different doses of sodium selenite on growth processes, photosynthesis characteristics, spring wheat yield and selenium accumulation in wheat under the conditions of selenium-deficient biogeochemical province in Transbaikalia were studied.

The composition of sulphur and nitrogen compounds contained in the bitumenoid isolated from Cambrian rocks oil shale formation was studied. It has been demonstrated that the sulphur compounds contain benzo-, dibenzo-, naphthobenzothiophenes and dibenzothiophene sulphoxides. Nitrogen compounds are presented by weak bases and neutral components. Among the weak bases, there are predominately alkyl homologues of dibenzoquinolone, dibenzothiaquinolone, dibenzoquinolinecarboxylic acids. The maximum in the distribution of neutral nitrogen-containing components corresponds to the alkyl derivatives of benzocarbazole and benzothiophenecarbazole as well as mononaphtheno derivatives of carbazolecarboxylic acids.

Basing on the components of an available naturally occurring renewable raw material, a synthesis of a novel chiral optically pure diamine belonging to diterpene series was realized. The tricyclic trans-1,2-diamine obtained and its derivatives could be used as ligand for metal complex catalysts of asymmetric reactions.

Results are reported concerning a model experiment for studying the physiological characteristics of two plant species, the activity of soil enzymes, the intensity of oil pollution accumulation and oil composition depending on the amount of oil introduced into the permafrost soil. It was suggested that with increasing the intensity of oil pollution, the soil-plant system mechanisms from the antioxidant and DNA repairing systems to apoptosis and SOS reparations. Introducing the same amount of oil into the soil (0.16 %) in the experiments with growing plants without them demonstrated that the action of the soil microflora resulted in the biodegradation of about one-third (32.2 %) of the oil introduced. In the case of plant growth (wormwood and peppergrass) the transformation of oil-caused contamination was much more profound amounting to 60.0 and 66.7 %, respectively. In the presence of the plants the process of destruction, alongside with n-alkanes and 2- and 3-methylalkanes, involve a wide range of structural isomers, including 12- and 13-methylalkanes and isoprenoids. As a result, the hydrocarbon composition of bitumenoids demonstrates changes direction toward restoring the natural geochemical background. The results obtained in studying the adaptive capacity of plants and the pollution transformation efficiency allow one to find out the maximum permissible residual oil contamination level in the soil, which level amounted to 0.1 %, or 1 g/kg of soil.

Studies concerning the liquid-phase catalytic reductive dechlorination of toxic man-made products using catalysts M/Sibunit (M = Ni, Pt, Pd) were performed. It has been demonstrated that the most pronounced activity is exhibited by catalysts based on palladium.

The reaction of catalytic hydrocracking the triglycerides of fatty acids from rapeseed oil with obtaining a mixture of С₁₂–С₁₉ alkanes on Ni–Cu/CeO₂–ZrO₂ catalyst under mild conditions (0.5 MPa Н₂, 300–380 °С) was studied. Basing on the distribution of hydrocracking products at different contact time and temperature values, a scheme is proposed for stepwise hydrocracking the triglycerides of fatty acids that takes into account the formation of oxygen-containing intermediate products (fatty acids, esters, alcohols, and waxes).

Using the method of Fourier transform infrared spectroscopy, a study was performed concerning the composition of surface functional groups inherent in birch activated carbon BAU-A as well as changing their qualitative and quantitative composition in the course of gold sorption from chloride solutions with different composition under the action of ultraviolet irradiation and without it. It has been demonstrated that under the action of UV irradiation the amount of hydroxyl groups on the surface of birch activated carbon exhibits an increase, which results in an increase in its sorption capacity for [AuCl₄]^– anions. The method of EXAFS spectroscopy revealed that after the sorption from hydrochloric acid solutions, gold on the surface of birch activated carbon is in the form of dimers Au₂Cl₆ both after ultraviolet irradiation and without it. The sorption mechanism is suggested to involve the following stages: ion exchange of surface hydroxyl groups for the complex ions [AuCl₄]^– as well as the formation of dimers Au₂Cl₆ on the surface of carbon.

Lead content in woody vegetation at the genetic profile level was investigated at the territory of Irkutsk, a large industrial centre of Eastern Siberia. It was demonstrated that lead income caused by technogenic emissions contributes significantly to the pollution of the urban ecosystem. Lead accumulation in needles and leaves of the woody plants at the urban area can exceed the background levels more than 10 times, maximally up to 25 times. The high level of lead is also revealed in the top humus and humus accumulative horizons. Its active vertical migration into textural illuvial and pedogenic horizons of the soil genetic profile was discovered. It is shown that the redistribution of the labile lead in the soil solution of the organic and mineral horizons is accompanied by its interaction with phosphate and sulphate ions, exchange cations (sodium, potassium, magnesium), and heavy metal ions (zinc, copper, cadmium, manganese). Reliable direct correlations between the content of mobile lead in urban soil and lead concentration in the assimilative organs of woody plants are revealed.

Obtaining dimethyl ether from synthesis gas with the use of a two-layer catalyst was studied. An optimum level-by-level loading was determined for two catalytic systems such as methanol production catalyst Katalco-58 and methanol dehydration catalyst γ-Al₂O₃ It was demonstrated that increasing the temperature and contact time results in increasing the CO conversion level and the yield of dimethyl ether, whereas their maximum values are attained at a pressure of 3 MPa. The optimum process conditions are: Т = 280 °С, Р = 3 MPa, Н₂/СО = 2, the contact time 6 s.

Reactions of (+)-limonene and (-)-β-pinene with hetarenesulphenyl chlorides (2-benzothiazolesulphenyl chloride, 3-methoxycarbonyl-2-pyridylsulphenyl chloride) were studied.

Basing on betulin vinylation by acetylene in superbasic medium KOH/DMSO, mono- and divinyl esters of betulin, valuable monomers and intermediates for the synthesis of polymers and biologically active compounds were obtained.