Delayed Coking Unit Research Articles

Study on Demulsification of the Oil-in-Water Emulsion from Column Top of a Delayed Coking Unit in Refinery. II. Synthesis and Application

Cationic demulsifiers in SM, LS series were synthesized for the oil-in-water emulsion (o/w) from the column top of a delayed coking unit in refinery, in which cationic demulsifier SM-11 in SM series had prominent demulsification efficiency. The conditions of synthesis and technological application of cationic demulsifier SM-11 were evaluated. Furthermore, cationic demulsifier SM-11 had also got a better result during industrial application.

Study on Demulsification of the Oil-in-Water Emulsion from Column Top of a Delayed Coking unit in Refinery. I

Demulsification study was carried out for the oil-in-water emulsion (o/w) existing the column top of delayed coking unit in refinery. The stability of such emulsion was investigated and various kinds of demulsifiers were evaluated. Some new kind of cationic demulsifiers were proved to be more efficient for this o/w emulsion. Furthermore, the cause of formation and steady existence of emulsion, and the mechanism of demulsification had also been investigated.

Thermal coupling between crude distillation and delayed coking units

The paper presents an industrial case study. Crude distillation unit (CDU) and delayed coking unit (DCU) are important plants in oil refineries, presenting huge energy consumption, especially due to high flowrates of process material streams. Any acceptable solution for energy saving is important in this context. The idea of thermal coupling between these two plants is good as they have potential to exchange energy, but the problem is to choose the most appropriate way to do it. The objective of this work is to present the possibility to exchange energy between the two plants, continuing a previous work [Energy saving by integration of CDU-delayed coke plants, third Conference, Process Integration, Modelling and Optimisation for Energy Saving and Pollution Reduction––PRES 2000, P7.72], where a part of the solution was already presented. The difficulty to find a solution arisen from the fact that DCU is working semi-continuous. More insights in the process allowed finding new possibilities, more attractive for rational use of energy, with better applicability. A feasibility study will be performed to give also economic sound of all the implications for the modifications proposed.

Preparation of feedstock for a delayed coking unit

Between-servicing operation of the 21-10/3M delayed coking unit and the quality of the coke produced are determined by the quality of preparation of the feedstock. Two of the fundamental canses of active clogging of the pipes in furnaces for thermal processing of heavy petroleum resids have been identified [1 – 3]: a high content of inorganic compounds in the feedstock and its low aggregate stability.

Experience in operating a delayed coking unit

Experience in operating a delayed coking unit

Modeling reactor hydrodynamics for delayed coking unit

Modeling reactor hydrodynamics for delayed coking unit

98/02553 Non destructive testing of Coke Chamber No. 1 of delayed coking unit at Digboi Refinery : Deka, D. K. Trends NDE Sci. Technol., Proc. World Conf NDT, 14th, 1996 (Pub. 1997), 2, 1035–1039. Edited by Nair, C. G., Krishnadas, Balkema, Rotterdam, The Netherlands

98/02553 Non destructive testing of Coke Chamber No. 1 of delayed coking unit at Digboi Refinery : Deka, D. K. Trends NDE Sci. Technol., Proc. World Conf NDT, 14th, 1996 (Pub. 1997), 2, 1035–1039. Edited by Nair, C. G., Krishnadas, Balkema, Rotterdam, The Netherlands

Model predictive control of a delayed coking unit with [DMC]: Development issues

Model predictive control of a delayed coking unit with [DMC]: Development issues

Radiational-thermal stability of hydrocarbons of aromatic oil obtained by adsorptive treatment

The oil investigated was obtained in a continuous pilot unit for adsorptive treatment of a heavy coker gasoil, produced in a commercial delayed coking unit from medium-sulfur feed. The radiational and thermal stability of the constituent hydrocarbons and individual groups of compounds was evaluated from the changes of their content in the oil after gamma irradiation from a cobalt 60 source. Chemical group composition was determined chromatographically. Resinous compounds were least resistant to radiation. The resistance of the organosulfur components was dependent on molecular structure; benzothiophene and dibenzothiophene contents were increased by irradiation from the conversion of naphthenobenzothiophenes.

Extending the useful life of coking chambers

The authors evaluate the useful life of delayed coking unit (DCU) coking chambers and the development of engineering measures to extend this life. Results obtained in an evaluation of the remaining useful life in the example of a DCU at the Volgograd Petroleum Refinery are examined. In an investigation of the physicomechanical properties of the metal, it was found that the base metal and the cladding layer meet the requirements of the corresponding steel standards as shown. A flow chart present the scheme for evaluation of remaining useful life of DCU coking chambers. Mechanical tests were performed at 20/sup 0/C and at the working temperature (475/sup 0/C) following standard procedures. The test results shown indicate that the strength characteristics of the metal, in service for over 20 years, meet the requirements for two-layer steel. Results are presented from a test of the influence of a bandage on the stress level in the shell of a DCU coking chamber at the deformed site, by means of strain gauge measurements in a hydraulic test.

Influence of process parameters on physicomechanical properties of petroleum coke

A study of the reactor temperature field in a delayed coking unit at the refinery yielded data on the rate of cooling, as great as 10 C/min at certain points. In the zones of the coke mass directly adjoining the channels, even higher cooling rates are realized. The authors investigated the distribution of the coefficient of thermal expansion (CTE) of the coke, the values of which were measured because of the established fact of simultaneous deformation of the coke cake with the reactor shell as a result of the difference in CTE between the coke and the metal of the vessel. The cokes used in these studies were obtained in a laboratory reactor in a test unit. The first stage of reversible crystallization takes place in the pitch phase; in the second, chemical bonds are formed, and the petroleum coke is formed directly.

Reconstruction of transport system in delayed coking unit

Describes the reconstruction of the processing and transport system of a delayed coking unit (DLC) in a petroleum refinery which produces electrode coke and coke breeze. Explains that the yield of electrode coke depends to a great degree on the operation of the transport system, which, according to design, includes flight conveyors for transportation and distribution of the coke among the storage sections, classifier screens installed on the conveyors, and a toothed-roll crusher to break up the coke. Presents a flow chart of the reconstructed system. Concludes that with the reconstructed unit, it has been possible to increase the operational reliability of the unit, to extend the running time between maintenance shutdowns to 6 months, to reduce the operating costs, and to increase the coke output by 12.2%; the yield of electrode coke was increased from 49.6% to 56.5%, and the yield of coke breeze was reduced from 50.4% to 43.5%. Notes that the annual economic advantage from carrying out the reconstruction was 362,000 rubles.

Protection of air and water basins at the industrial association ?Angarsknefteorgsintez?

Discusses the development and implementation of environmental protection measures for petroleum refineries. Describes a scheme for cooling the vacuum-tower hydrocarbon vapor and gases formed by decomposition, which made it possible for 2 crude oil primary distillation units to eliminate the discharge of petroleum products to the sewer system and to the atmosphere. Reports that the introduction of air-cooled exchangers by the Association has improved operating stability and has reduced the amount of discharges to the environment. Reviews measures that have been developed to ensure good operation of the sulfur removal section of a delayed coking unit. Reveals that a compressor station for compression of gas from catalytic cracking will reduce the discharge of carbon oxides and hydrogen sulfide, and will eliminate flaring. Points out that considerable work is also being performed in the Association on curtailing the discharge of wastewater pollutants (e.g., flotation units, nozzles for furnaces, FAZA-70 level indicators, overflow schemes).

?Intensification? of delayed coking unit operation

?Intensification? of delayed coking unit operation

Improvements in operation of delayed coking unit at Nadvornaya refinery

Improvements in operation of delayed coking unit at Nadvornaya refinery

The workers' collective of the Novo-Ufa Order-of-Lenin-and-Order-of-the-October-Revolution Petroleum Refinery greets the 60th anniversary of the October Revolution in a worthy manner

Process technology has been developed and put into commercial service for the production of a component of carbon-black feedstock in a delayed coking unit; this has permitted a considerable increase in the output of thermal gas oil. After reconstruction, one of the thermal cracking units was used to produce thermal gas oil from various products obtained in catalytic cracking, coking, and lube oil treating (solvent extracts); the other two units were used for primary crude oil processing.