Study of asphaltene deposition from Tahe crude oil

Borehole blockage caused by asphaltene deposition is a problem in crude oil production in the Tahe Oilfield, Xinjiang, China. This study has investigated the influences of crude oil compositions, temperature and pressure on asphaltene deposition. The asphaltene deposition trend of crude oil was studied by saturates, aromatics, resins and asphaltenes （SARA） method, and the turbidity method was applied for the first time to determine the onset of asphaltene flocculation. The results showed that the asphaltene deposition trend of crude oil by the turbidity method was in accordance with that by the SARA method. The asphaltene solubility in crude oil decreased with decreasing temperature and the amount of asphaltene deposits of T739 crude oil （from well T739, Tahe Oilfield） had a maximum value at 60℃. From the PVT results, the bubble point pressure of TH 10403CX crude oil （from well TH10403CX, Tahe Oilfield） at different temperatures can be obtained and the depth at which the maximum asphaltene flocculation would occur in boreholes can be calculated. The crude oil PVT results showed that at 50,90 and 130 ℃, the bubble point pressure of TH 10403CX crude oil was 25.2, 26,4 and 27.0 MPa, respectively. The depth of injecting asphaltene deposition inhibitors for TH10403CX was determined to be 2,700 m.

Intraspecific Chemical Variability of Essential Oil of Hoslundia opposita

Chemical investigation on leaves oil of Hoslundia opposita, aromatic plant used in traditional medicine, harvested from 20 localities of C?te d’Ivoire was realized by GC and GC/MS. In total, 101 compounds were identified accounting to 92% - 99%, aromatic compounds such benzyl benzoate and sesquiterpenes namely germacrene D, β-caryophyllene and α-humulene hydroxyl were found as the major constituents. As regard, the chemical profiles of our samples, it was found a great chemical variability suggesting a high polymorphism degree. In order to study this chemical variability, the results were submitted to the principal components and cluster analysis which allowed distinguishing two main groups of essential oils with respect to sampling site. The cluster I was dominated by benzyl benzoate (15%) and thymol (7.4%) comprising 6 localities, cluster II was characterized by phytol (8.5%) and α-humulene (7%) and constituted by 14 localities.

Micro- and nanoporous materials capable of absorbing solvents and oils reversibly： the state of the art

Treatment of petroleum spills and organic solvent pollution in general is an important issue; several techniques are under development to remove oil from water. The use of absorbents is one of the most common techniques to tackle this problem. These absorbents can be classified based on their characteristics of recyclability into irreversible and reversible ones. In this review, we discuss the application of several materials as oil absorbents, according to their classification and characteristics such as hydrophobicity, surface area and oil absorption capacity. Also, the fabrication methods for some materials are presented and analyzed.

Influence of Oil Paper Composition on the Space Charge Characteristics

Space charge inside oil paper insulation can severely distort the electric field distribution and lead to degradation of electrical performance of materials.A vast number of articles about the space charge characteristics of oil paper insulation under different conditions has been published;however,few report the influence of oil paper composition.In this paper,a comparison of the space charge distribution as well as the electrical conductivity of four combinations of transformer oil(Kunlun#25 and Nynas oil)and paper(type I from XD factory,type II imported from France)is carried out.The results show that the combination of type II paper and Kunlun oil performs well with minimal charge accumulation inside the materials.To understand the phenomenon,results of space charge measurements and electrical conductivity are associated.A microscopic inspection of two types of paper is conducted to acquire the surface condition of the paper.The relationship between space charge injection quantity and surface condition of the papers is discussed.It is observed that a relatively higher conductivity of oil as well as a smooth,dense surface of paper can suppress space charge in oil paper insulation.

COMPOSITION OF SEA BUCKTHORN OIL AND ITS MEDICAL ASPECTS

The composition of sea buckthorn oil (Hippophac rhamnoides) from north China was analyzed by means of gas chromatography. high pressure liquid chromatography and thin layer chromatography and thin layer chromatography. This wild vegetable oil consisted of many unsaturated fatty acids, e.g. almitoleic acid (13.9%). oleic acid (27.9%), linoleic acid (23.2%) and linolenic acid (14.9%). α-tocopherol (105.2 mg/ 100g),β-tocopherol (8.3 mg/ 100). γ-tocopherol (52.7

海拔高度因素对伊朗Nour巴拉代区产多头菊蒿挥发油含量及质量的影响(英文)

Medicinal plant are grown and produced in different ecosystems and sites under the influence of different potential factors,including the altitude as one of the vital determinants in the quantity and quality of the plants.One of the species that grows in the highlands is Tanacetum polycephalum,an aromatic perennial of the Asteraceae.This species is characterized to be antiseptic,analgesic,anesthetic,disinfective,expectorant,anti-cancer,anti-allergic,and conducive to low blood pressure.The purpose of this study is to investigate the essential compositions in the aerial parts of T.polycephalum at the time of flowering,and in three different altitudes of the Baladeh region of Nour.Thus,the essential oil was extracted from the aerial parts in the flowering stage of the plant at three altitudes of 1 600,2 400 and 3 200 m using a water distillation method,and the essential oil compositions were identified using GC and GC/MS instruments.One-way ANOVA method was conducted to analyze the obtained data using SPSS,and a Duncan test was administered to compare the means.The results indicated that the essential output obtained from the altitudes of 1 600,2 400 and 3 200 m was(0.74±0.01)%,(1.09±0.02)%,and(1.32±1.2)%,respectively,so that the altitude of 3 200 m revealed the greatest quantity,and the altitude of 1 600 m represented the smallest quantity.Moreover,the essential oil compositions showed the highest percentage in the altitude of 3 200 m and the lowest percentage at the altitude of 1 600 m.The results showed that as the altitude increases,the essential oil compositions revealed the greater quantity and percentage in the aerial parts of T.polycephalum.

Composite microcapsules with enhanced mechanical stability and reduced active ingredient leakage

A calcium shellac （CS） matrix was used to encapsulate polymeric melamine formaldehyde microcapsules （A） or CaCO3 nanoparticles-stabilized microcapsules （B）, both of which encapsulated an oil-based active ingredient, producing A-CS or B-CS composite microcapsules. The mechanical properties and oil release profiles of the composite microcapsules were evaluated. The composite microcapsules showed enhanced mechanical stability and reduced leakage of the active ingredient hv one order of magnitude.