Search

Copper stearate was applied as a catalyst for the oxidation of heavy oils. The catalytic effect was investigated by high-pressure differential scanning calorimetry (HP-DSC) and accelerating rate calorimetry (ARC). The results showed that copper stearate significantly improved the oxidation performance including decreasing activation energies, enhancing combustion efficiency of coke, and reducing induction time and ignition temperature. CuO nanoparticles were in-situ formed due to the decomposition of copper stearate. To understand the catalytic mechanism, the catalytic effect of copper stearate was compared with nickel stearate, iron stearate and CuO. Furthermore, the existed form and transition of copper stearate during the oxidation process of crude oil were investigated using thermogravimetric analyser coupled with FTIR-spectrometer (TG-FTIR), HP-DSC, X-ray diffraction (XRD), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The results indicated that copper stearate and in-situ formed CuO nanoparticles played their catalytic roles as a homogeneous and heterogenous catalyst in low and high-temperature ranges, respectively. It was believed that the high catalytic activity of CuO can be not only attributed to those well-known catalytic mechanisms, but also benefits from the well-distribution of both copper stearate and in-situ formed CuO nanoparticles.

In this paper, we demonstrate that dicalcium salt of 1-hydroxyethane-1,1-diphosphonic acid (HEDP) can be used as a component of nucleating agents for isotactic polypropylene (iPP) - one of the most widely used commercial polymers. Based on dicalcium HEDP salt novel nucleators show high efficiency in the nucleation of iPP α-crystals. At a concentration of 0.25 wt% the nucleators demonstrate an increase in crystallinity (+ 1.5 % in composition with calcium stearate and + 4% - with zinc stearate). When the dicalcium HEDP salt based nucleator is added to the iPP, the flexural modulus increases by 8–12 %. Assumptions are suggested about the mechanism of action of the new nucleator, based on its core-shell structure. The main component of the nucleating agent, the dicalcium HEDP salt, is synthesized by the one-step reaction in a non-toxic aqueous medium with commercially available reagents. The synthetic protocol gives a finely friable product that does not require further grinding. The synthesis is cheap and environmentally friendly since only deionized water is used as a solvent.

In this study, oil-soluble transition metal-based catalysts (Fe, Co, Ni) are proposed for catalyzing aquathermolysis reactions in steam injection process for heavy oil production to achieve in-situ upgrading of heavy oil. Their catalytic performance and possible mechanism were investigated by autoclave experiments together with a comprehensive analysis of the change in physical and chemical properties of the upgraded oil using SARA analysis, viscosity measurement, GC, GC–MS, FTIR, and 13C NMR, etc. Simultaneously, the in-situ transformation of these catalysts was also analyzed by TG-FTIR, XRD, and Mossbauer spectra, etc. to better under the possible catalytic mechanism. The results showed that the in-situ transformation of these oil soluble catalysts occurred during the thermal treatment process at 250 °C and 300 °C, and their metal-based complexes, oxide, sulfide, and sometime pure metal were in-situ generated and played a catalytic role for aquathermolysis reactions. These catalysts showed a good catalytic performance at 300 °C for heavy oil upgrading in reducing viscosity, increasing saturates content (especially low molecule weight alkanes), decreasing resins and asphaltenes content, removing sulfur and nitrogen, and decreasing polyaromatics content, etc. by inhibiting the condensation and recombination reactions and promoting thermal decomposition reactions of heavy components (resin, asphaltene, and polycyclic aromatics, long chain alkanes, etc.) and hydrogenation reaction. Nickle gives the best catalytic performance. The low cost and easy access together with its high catalytic activity make its wide application a great potential in catalyzing aquathermolysis reaction in steam injection process for in-situ upgrading and heavy oil recovery.