نتایج جستجو برای: wax appearance temperature
تعداد نتایج: 541648 فیلتر نتایج به سال:
The effect of wax molecular weight distribution on the efficacy two alpha olefin-maleic anhydride paraffin inhibitors (PIs) having different densities alkyl side-chains were examined in light West Texas crude absence and presence asphaltenes. Interpretation data was aided by cross-polarization microscopy. Primary differences crystal morphology appear to be driven composition wax, with secondary...
We have investigated how four different pour point depressant (PPD) polymers affect the pour point transition in mixtures of a single pure wax in a solvent. We used either n-eicosane (C20), CH3(CH2)18CH3, n-tetracosane (C24), CH3(CH2)22CH3 or n-hexatriacontane (C36), CH3(CH2)34CH3 as the wax component with either n-heptane or toluene as the solvent component. For all wax-solvent combinations, t...
High molecular weight paraffin/wax precipitates in the solution of crude oil when surrounding temperature falls below wax appearance temperature, which causes problem deposition pipelines. To enhance rheology and lessen deposition, pour point depressants (PPDs) flow enhancers were utilized. These substances change crystals’ morphology, reducing crystal interlocking preventing agglomeration from...
Thermal stresses in three brands of inlay waxes were numerically analyzed under different cooling conditions using the rheological and thermal properties of waxes. On the basis of this analysis , the shrinkage of the wax pattern was calculated. The larger the stress relaxation of the wax and the higher the ambient temperature, the smaller the thermal stress induced in the wax. The shrinkage of ...
Gao and Sonin (1994) have proposed a method for rapid prototyping and microfabrication by precise deposition and solidification of molten microdrops. Objects can be fabricated by a drop-on-demand, computer-controlled droplet generator. To understand the fundamentals of droplet deposition and solidification, experiments have been conducted using microcrystalline wax droplets (Schiaffino and Soni...
Pour Point Depressant (PPD) Testing are used extensively to modify the crystallinity of hard waxes and reduce natural pour point crude. The best PPD chemical dosage for crude oil treatment will be chosen based on laboratory test results to: Reduce oil; viscosity Improve rheological properties wax deposition rate pipeline restart pressure. performance evaluation PPD, proposed use at X Oil Field ...
A procedure is presented for the simultaneous prediction of fluid–fluid and solid–fluid equilibrium of light gases/heavy hydrocarbons systems under pressure. The objective of this work is to simplify the predictive approach previously proposed by the authors, making it more useful and accessible to users at the petroleum industry. The main modification with respect to the complex LCVM (linear c...
The thermodynamics of wax formation in crude oils is examined and additional insights obtained into the problem. We show that a correlation for cloud point, or wax apppearance temperature, obtained for pure-substance waxes may be extended to mixtures of hydrocarbons, thereby generalising the usefulness of the correlation. We apply the colligative equation for freezing point depression to quanti...
The cuticle covers the aerial portions of land plants. It consists of amorphous intracuticular wax embedded in cutin polymer, and epicuticular wax crystalloids that coat the outer plant surface and impart a whitish appearance. Cuticular wax is mainly composed of long-chain aliphatic compounds derived from very long chain fatty acids. Wax biosynthesis begins with fatty acid synthesis in the plas...
BACKGROUND AND PURPOSE Bone wax is a hemostatic agent that has been reported in some instances to migrate into the sigmoid sinus following posterior fossa surgery. The purpose of this study was to characterize the CT and MR imaging findings of this entity. MATERIALS AND METHODS The study included 212 consecutive patients who underwent posterior fossa surgery and postoperative CT and contrast-...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید