Search

Transformations of high-molecular-weight compounds of oil sand natural bitumen under the heat treatment were studied in this work. For that purpose the natural bitumen isolated from oil sand taken from the Beke field (Kazakhstan) was used as a substrate. Thermal processing of natural bitumen leads to a general change in the chemical composition of components and to an increase in the output of certain fractions. The contents of oil, tar and asphaltenes were determined and the elemental composition of tar-asphaltene compounds was evaluated. Molecular structures of the tar and asphaltene components of natural bitumen before and after cracking have been defined from the data of elemental analysis, NMR spectroscopy and molecular weight. The high molecular compounds were presented as giant molecules containing small aromatic islands some of which were linked by aliphatic chains, that was proved by infrared spectroscopy.

In the production of sulfuric acid, sulfur cake—a waste product of the sulfur purification process—is formed in large quantities, which requires its disposal and use. For its use in composite materials, modification is necessary to convert sulfur into a polymer form. The aim of the study was to develop a method for modifying sulfur cake—a waste product of sulfuric acid production—for its disposal. Available reagents—styrene, glycerol, and oleic acid—were tested as modifiers in the work. The sample compositions consisted of 100% sulfur cake (no. 1) and its mixtures: 97% sulfur cake + 3% styrene (no. 2), 97% sulfur cake + 3% glycerol (no. 3), 97% sulfur cake + 3% oleic acid (no. 4), 95% sulfur cake + 3% styrene, 1% glycerol, and 1% oleic acid (no. 5). Modification of sulfur cake was carried out at a temperature of 140 °C for 30 min. The composition, crystal structure, and thermal properties of the samples of the original and modified sulfur cake were studied using X-ray phase and X-ray structural analyses, IR spectroscopy, differential scanning calorimetry, differential thermal and thermogravimetric analysis. The optimal modifier for sulfur cake was a mixture of styrene, glycerol, and oleic acid, which led to the formation of acetal (polyoxymethylene) and an improvement in the structure due to a decrease in the content of impurities. Modification of sulfur cake with styrene resulted in the appearance of a CAr–S bond band at 571 cm−1, and modification with oleic acid a C–S band in the region of 694 cm−1 in the IR spectra. The results of differential scanning calorimetric analysis showed an increase in the heat of fusion of sulfur by 12.45 J/g in the samples of sulfur cake modified with glycerol and styrene. Modification of sulfur cake with oleic acid and a mixture of reagents resulted in the appearance of a third peak with maxima at 244.2 and 264.0 °C, which demonstrated a significant effect of the indicated additives on the thermal behavior of the sulfur cake. Proposed schemes for modifying sulfur cake with styrene and oleic acid are presented. [ABSTRACT FROM AUTHOR]

Oil sludge is one of the main pollutants generated by the oil industry. Due to serious pollution and increasing oil production, problems arise every year in the effective treatment of oil sludge. The current study examines the composition and physicochemical characteristics of oil sludge, as well as traditional and new methods for processing oil sludge. With the tightening of environmental protection requirements, oil sludge quality reduction, recycling, and harmless treatment technologies will become necessary in the future. The primary task was to determine the composition of tank oil sludge, separate it from mechanical impurities, and study the influence of ultrasonic treatment and subsequent atmospheric distillation on the extract. The separation of the concentrate and the composition of the tank oil sludge, using an extracted mixture of hexane and benzene, are considered. The use of modern SEM methods, elemental analysis, NMR analysis, IR, ultrasound, and GC–mass spectrometry made it possible to characterize the organic part of reservoir oil sludge and its distillation products. First, 300 g of tank oil sludge was preheated and mixed with 300 mL of solvent (hexane:benzene = 1:1). After mixing with the solvent, the result mixture was filtered. Then, it was placed in an ultrasonic bath and exposed to ultrasound at a frequency of 100 kHz for 30 min. After processing, it was extracted in a Soxhlet apparatus at a temperature of 65 °C to isolate the extract. The resulting extract was analyzed on a gas chromatograph with mass detection. The composition of the extract was as follows (in %): hexane—83.99; total hydrocarbon isomers—7.12; n-hydrocarbons—2.52; benzene—6.37%. At a temperature of 85 °C, the benzene yield was 65.85%. It has been established that the fractions obtained through the distillation of oil sludge at temperatures of 65–85 °C have improved dissolving capacity. It has also been shown that the use of these fractions promotes an increase in the content of hydrocarbon isomers by 12–13% in the extract composition. [ABSTRACT FROM AUTHOR]

Demetallization and desulfurization of vacuum residuum from the Pavlodar Petrochemical Plant (Kazakhstan) was carried out by adsorbents based on zeolite modified with titanium compounds and vanadium oxide. The process was carried out at a temperature of 320-360°C for 1 to 3 hours at atmospheric pressure. The results of determining the physico-chemical characteristics of the modified adsorbents showed that, after modification, their specific surface area increases, but the specific pore volume decreases. The maximum degree of demetallization is observed when using an adsorbent based on zeolite modified with titanium oxides and vanadium oxides. The change in the structure of vanadylporphyrins in vacuum residuum composition after the demetallization process is determined. After demetallization etioporphyrins have C27-C32 with a center of mass at C29, phylloporphyrins have C28-C34, after treatment at 360 °C, the center of mass shifts towards an increase in the number of carbon atoms C31. [ABSTRACT FROM AUTHOR]

The paper presents the results of thermal cracking of natural bitumens of the Beke and Munaily Mola oil sand deposits (Kazakhstan). The data obtained show that the high-molecular components of the bitumen of the Munaily Mola deposit are more easily cracked than those of the Beke deposit. The cracking of natural Beke bitumen in a medium of water vapor, acetonitrile and isopropanol is studied at different temperatures and pressures. The effect of the heterogeneous additive - nano-sized copper (II) oxide on the cracking efficiency of natural bitumen components is identified. The total yield of gas and coke is 3.2%, while the distillate fractions is 40.8 mass % in case of cracking of the Beke natural bitumen in a flow reactor. [ABSTRACT FROM AUTHOR]