Oman Crude Oil Research Articles

Effect of fluorine on hydrodenitrogenation activity of doubly promoted (Zn + Co) molybdena-alumina catalysts

By employing the EXTRACT module in Aspen Plus Software with the aid of selected PSRK equation from our previous work [W. Li, P. Du, F. Cao, W. Ying, D. Fang, Simulation and optimization of the extract segment of solvent deasphalting plant, Computers and Applied Chemistry, 26 (2009) 455–460] [18], this work simulated a solvent deasphalting (SDA) process with mixed C4 solvent and the feedstock of vacuum residue (VR) obtained from a mixed crude oil (Zhongyuan oil:Tahe oil:Changqing oil:Oman crude oil:Zafiro crude oil = 35:5:2:40:18, wt/wt). The feed of VR was lumped as paraffinic, primitive and aromatic components according to their calculated KUOP values. The relative errors not more than 3.94% illustrated the simulated results are comparable with the industrial data for both feedstock (VR and mixed C4 solvent) and products (deasphalted oil—DAO and deoiled asphalt—DOA). The DAO yield was predicted to reduce to 47.2% from 58.0% with increasing temperature of mixed C4 solvent from 100 to 120 °C under operating model-I, but increased from 51.6% to 56.1% with solvent–VR ratio up to 6.5 from 4.5. In addition, a heavier mixed C4 solvent would facilitate remarkable improvement of DAO yield but deteriorate its quality.

RECENT ACTIVITIES OF THE PRIVATE OIL SPILL COOPERATIVE IN JAPAN

ABSTRACT The grounding of the Juliana, a crude tanker, off the Niigata Port, in late November 1971, caused the first major oil spill in Japan, a spill of 7,200 kL (45,000 bbl) of Oman crude oil. The member companies of Petroleum Association of Japan (PAJ) hurriedly sent their oil booms and chemical dispersants to Niigata under the instructions of the headquarters set up in the secretariat of PAJ. This accident showed the oil industry the necessity of a nationwide network to supply oil cleanup equipment and materials in an emergency. In January 1973, a nationwide oil spill cooperative in Japan was initiated, with the agreement of 51 oil companies of PAJ. The organization of 47 branches covered all the Japan Islands, stretching about 3,000 km from Hokkaido to Okinawa. Each branch represents several petroleum facilities, a total of about 380. This oil spill cooperative has continued to act effectively. The utility of the arrangement has been proved clearly through provision of about 30 percent of the oil cleanup equipment and materials in Japan.

The occurence of unusual C 27 and C 29 sterane predominances in two types of Oman crude oil

Two types of Oman crude oils reveal unusual sterane distributions. Type “A”, which is the more common (74 examples), is characterised by a predominance of C 29 iso- and normal-steranes and generally none or only very low relative concentrations of rearranged-steranes. The triterpanes are characterised by the predominance of the C 29 17αH, 21βH norhopane over the C 30 17αH, 21βH hopane and non-predominant C 20–C 30 tricyclic terpanes. The C 29 steranes of this type of crude were not derived from the C 29 sterols of land-plant origin (frequently proposed as the source of C 29 steranes) since there is good geological evidence that these crudes were generated from a pre-Cambrian source rock, a geological period when land-plants did not exist. The type “B” crude oil (11 known examples) is characterised by a strong predominance of C 27 iso-, normal- and rearranged-steranes, relatively lower concentrations of 17αH, 21βH hopanes and relatively high concentrations of C 20–C 30 tricyclic terpanes. The remarkably different biomarker characteristics of these crude oils imply that the organisms active in the depositional environment of the respective source rocks were significantly different.

Effects of oil dispersants and oil emulsions on marine animals

The toxicities to marine animals of nine oil dispersants, three oil emulsions with Corexit and of a dispersion of Oman crude oil, have been studied in continuous flow aquarium systems at 96-h exposures followed by a recovery period in clean sea-water. New types of dispersants were found to be less toxic than older types and oil emulsions more toxic than dispersants alone or crude oil alone. Fishes and bivalves were found most sensitive. Crustaceans were the most resistant to dispersants but very susceptible to oil emulsions. The tolerance of different species was found to be related to their mode of life, more active species being more susceptible. Delayed mortality of bivalves increased their susceptibility if the recovery period was included. Effects on locomotory behaviour of fishes and crustaceans, breathing rate of fish, valve-closure of bivalves and byssal thread formation of common mussels have been demonstrated for both dispersants and oil emulsions. The general sequence of such effects was: increased activity; successively impaired activity; immobilization; and death. Recovery is good for fish and crustaceans but poor for bivalves due to the delayed effects. Ecological consequences of dispersants and oil pollution in the marine environment are discussed.