Sudan Khartoum Refinery Co. has selected a unique route featuring delayed coking of crude in connection with the highly sour and high-calcium heavy crude extracted from Sudanese oil block No. 6.The crude oil after pre...Sudan Khartoum Refinery Co. has selected a unique route featuring delayed coking of crude in connection with the highly sour and high-calcium heavy crude extracted from Sudanese oil block No. 6.The crude oil after pretreatment for calcium removal is subjected to coking for removal of acids and metals with the coker products being further processed. The crude oil extracted from Sudanese oil block No. 6contains as high as 13 mg KOH/g of crude in addition to a calcium content of 1600 ppm. This article makes an analysis on problems related with the operation of commercial delayed coking unit for processing of highly sour crude and bring forth measures to solve these problems. The liquid yield resulted from coking of crude oil can reach 82m%, and the petroleum coke can meet the quality requirement for class 3B petroleum coke.展开更多
A cDNA(af1) encoding farnesyl pyrophosphate synthase AaFPS1 (FPS, EC2.5.1.1/EC2.5.1.10) from a high yield Artemisia annua strain 025 has been cloned from its cDNA library. Sequence analysis showed that the cDNA en-cod...A cDNA(af1) encoding farnesyl pyrophosphate synthase AaFPS1 (FPS, EC2.5.1.1/EC2.5.1.10) from a high yield Artemisia annua strain 025 has been cloned from its cDNA library. Sequence analysis showed that the cDNA en-coded a protein of 343 amino acid (aa) residues with mo-lecular weight of 39 kD. Deduced aa sequence of the cDNA was similar to FPS from other plants, yeast and mammals, containing 5 conserved domains found in both prenyl trans-ferase and polyprenyl synthase. The expression of the cDNA in Escherichia coli showed measurable specific activity of FPS in vitro. The enzyme was purified by ion exchange chromatography and its kinetics was measured. These re-sults would further promote the molecular regulation of ar-temisinin biosynthesis.展开更多
文摘Sudan Khartoum Refinery Co. has selected a unique route featuring delayed coking of crude in connection with the highly sour and high-calcium heavy crude extracted from Sudanese oil block No. 6.The crude oil after pretreatment for calcium removal is subjected to coking for removal of acids and metals with the coker products being further processed. The crude oil extracted from Sudanese oil block No. 6contains as high as 13 mg KOH/g of crude in addition to a calcium content of 1600 ppm. This article makes an analysis on problems related with the operation of commercial delayed coking unit for processing of highly sour crude and bring forth measures to solve these problems. The liquid yield resulted from coking of crude oil can reach 82m%, and the petroleum coke can meet the quality requirement for class 3B petroleum coke.
基金This work was supported by the National Natural Science Fundation of China (Grant No. 30171142).
文摘A cDNA(af1) encoding farnesyl pyrophosphate synthase AaFPS1 (FPS, EC2.5.1.1/EC2.5.1.10) from a high yield Artemisia annua strain 025 has been cloned from its cDNA library. Sequence analysis showed that the cDNA en-coded a protein of 343 amino acid (aa) residues with mo-lecular weight of 39 kD. Deduced aa sequence of the cDNA was similar to FPS from other plants, yeast and mammals, containing 5 conserved domains found in both prenyl trans-ferase and polyprenyl synthase. The expression of the cDNA in Escherichia coli showed measurable specific activity of FPS in vitro. The enzyme was purified by ion exchange chromatography and its kinetics was measured. These re-sults would further promote the molecular regulation of ar-temisinin biosynthesis.
