In brief, the process heats the residual oil from the vacuum distillation unit in a petroleum refinery to its thermal crackingtemperature in the heat transfer tubes of a furnace. For more than seven decades, lummus technology has been designing and supplying furnaces for delayed coking projects. In the delayed coking case, all liquid products must be hydrotreated prior to. This twoday course will cover an introduction to the process, equipment, and operation of a delayed coker unit dcu in the refinery.
A delayed coker unit is a type of coker that utilizes multiple pairs of drums working in tandem, sometimes as many as eight at a time, to recover specific elements from feedstock residues, tar pitch, and residual oils. The delayed coking process is a thermal process and consists of fired heaters, coke drums and a main. A catalytic delayed coking process is disclosed that gives increased distillate yield and reduced coke make. Support facilities include closed blowdown, coke cutting and handling, and a water recovery system. Delayed coking unit how to improve the process performance. Flowserve corporation 5215 north oconnor boulevard suite 2300 irving, texas 75039 north america latin america europe.
Hazards of delayed coker unit dcu operations august 2003 once removed from the coke drums, the coke is transported away from the receiving area. Thermal stability of the heavy oil in the vacuum unit make it difficult to cut deep. Petroleum residue upgrading via delayed coking publications of. Delayed coking valve number valve description design temperature range design pressure range pipe size. The feedstock is fed directly to the bottom of the fractionator where it is heated and lighter. To delay the coking process and subsequent fouling of the furnace tubes with solid coke, the hot feed velocity through the tubes is controlled, typically between six to ten feet per second.
In the training module on the delayed coker process, a typical coking process and decoking cycle operation. If the valves do not isolate, the unit will be shutdown. Fundamentals of delayed coking joint industry project jip. Resid hydrocracking better than delayed coking in case.
Delayed coker feed originates from the crude oil supplied to the refinery. These projects have ranged from small single heaters to the current multiheater installations with air preheat systems. This cracks the heavy, long chain hydrocarbon molecules of the residual oil into coker. The flexicoking process, developed by exxon research and engineering company, is, in fact, a fluidized bed coking process that is operated in a unit including a reactor and burner, often referred to as a heater, also including a gasifier for gasifying the coke product by reaction with an airsteam mixture to form a low heating value fuel gas. Petroleum downstream crash course 17 delayed coking. In the delayed coking process, the residual oil is heated to its cracking temperature in a furnace. Until recently, expected coker yields were determined by a simple laboratory test of the feedstock. This is done through a process called cracking, and involves using heat and pressure to break down long chains of hydrocarbons.
Each batch process cycle requires 25 or more manual operations valve, winch operation, drum heading. The process thermally cracks the long chain hydrocarbon molecules in the residual oil feed into shorter chain molecules. Petroleum downstream crash course 17 delayed coking youtube. Thermal stability of the heavy oil in the vacuum unit make it difficult to. Delayed coker free download as powerpoint presentation. Oct 29, 2015 delayed coker unit pinch an article from linhoffmarch on how to do a pinch for delayed coker unit with examples and calulations. Bitumen silt which is a result the oil recovery process. Cracking begins in the furnace, continues in the transfer line, and finishes in the coke drum. The coker furnace or heater, h1, heats the feed to the temperature at which thermal cracking occurs, typically between 900 of and 950 of. Delayed coking process and a photograph of a delayed coking unit. To understand the delayed coking process, one must understand how the delayed coker is integrated with the rest of the refinery. Exports of petroleum coke accounted for about 19% of the nations finished petroleum product exports through october. Consultant expert witness lng liquefied natural gas.
In a refinery the delayed coker unit process is a type of coking process where residual oil from vacuum distillation column is converted to low molecular weight hydrocarbon gases, naphtha, etc. The process a refinerys delayed coking unit is not new technology, but is the most common process to upgrade the residual hydrocarbons remaining after upstream processing to remove water and soluble salts in the crude desalter. First unit built in 1929 some 150 units built since then 56 in the us alone. The coker is unique in the refinery world with a batch process and specialized solids removal decoking and handling equipment.
Pdf advanced control of the delayed coking unit in khartoum. We would appreciate hearing from you about this document. F high temperatures will result in excessive thermal cracking and heater fouling this results in excessive amounts of gas oil being sent to the delayed coker. The process promotes the release of these lateforming cracked volatiles, allowing them to escape into the gas phase by breaking the solid coke into small particles. Delayed coker unit process animation yes yen graphitech. Baytown refinery coker facility, tx hydrocarbons technology. Lift plug and 4way switch plug valves for delayed coker unit dcu. In its simplest terms, delayed coking is a semibatch thermal cracking process using alternating drums that are switched offline after filling. The feed to coker is usually vacuum residue which is high on asphaltenes, resins, aromatics. Visbreaking and delayed coking linkedin slideshare. Delayed coking process animation dcu unit operation.
A simplified flow diagram of the delayed coker plus hydrotreating unit htu case is shown in fig. The process includes a furnace, two coke drums, fractionator. Delayed coking is one of the unit processes used in many oil refineries. The coker cracks converts the asphaltlike feedstock to a combination of products for further processing to gasoline and diesel feedstock, a coallike material called petroleum coke, plus light gas. Internet resources the search entry, delayed coker unit, yields many sources of information that are believed to be useful.
A delayed coker is a type of coker whose process consists of heating a residual oil feed to its thermal cracking temperature in a furnace with multiple parallel passes. Delayed cooking is one of the most difficult refinery units to operate and control. Delayed coker feed material delayed coker coker feedstock is material from the refinery vacuum unit, which is otherwise used as road asphalt. Delayed coking delayed coking is a type of thermal cracking in which the heat required to complete the coking reactions is supplied by a furnace, while coking itself takes place in drums operating continuously on a 24 h filling and 24 h emptying cycles. Bechtel corporation was chosen to design, develop and construct the delayed coker process unit. We would not recommend that anyone begin coker apc work without such support as the coker is a demanding unit, and. From here, the coke is either exported from the refinery or crushed, washed, and stored prior to export. The main objective of the delayed coking unit is to convert low value residual products to lighter products of higher value and to produce a coke product. Delayed coking process design, operations and optimization may 2012 canada coking conference.
The heating in the delayed coker unit operation, cracks the long chain heavy carbon and hydrogen molecules to facilitate the coking process. The schematic process flow diagram and description in this section are based. Delayed coking process design, operations and optimization may 2012 canada coking conference october 2226, 2012. F in a highly optimized unit design thermal cracking in the fired heater has been reported to be as low as 680. Coking is a refinery process that produces 19% of finished. Sep 17, 2017 the delayed coker unit animation describes the coking process in a step by step manner.
Typical process flow diagram with critical pumps and valves. However, as mentioned above, larger units may have as many as four pairs of drums eight drums in total as well as a furnace for each pair of coke drums. If the valves do not positively isolate the coker drum, product could leak into an offline drum causing a safety hazard to the personnel. Londono principal process engineer delayed coking process advantages benefits of delayed coking foster wheeler in the delayed coking industry. This results in excessive amounts of gas oil being sent to the delayed coker. Delayed coking a delayed coking is a type of coking whose process consists of heating a residual oil feed to its thermal cracking temperature in a furnace with multiple parallel passes. The valves isolating the feed heaters are also critical to operation when it becomes necessary to decoke a heater. A schematic flow diagram of the delayed coking is shown in figure below.
A coker or coker unit is an oil refinery processing unit that converts the residual oil from the vacuum distillation column into low molecular weight hydrocarbon gases, naphtha, light and heavy gas oils, and petroleum coke. Fluor daniel company is in charge of making modifications to existing utility and processing units. The heating in the delayed coker unit operation, cracks the long chain heavy carbon. The process configuration of a delayed coking unit resembles that of visbreaking figure 5.
Delayed coking is one of the chemical engineering unit processes used in many. Page 38 the hot product vapours from the filling drums will be routed to the coker fractionator. In its simplest terms, delayed coking is a semibatch. Delayed coking process animation dcu unit operation duration. In addition to the recovery of additional and more valuable volatiles, there are other benefits of the new process compared with the delayed coking process. A delayed coker is a type of coker whose process consists of heating the residual oil feed to its thermal cracking temperature in a multi parallel pass furnace. Process description a closer look at delayed coker and hydraulic decoking technologies. The coking unit converts heavy feedstocks into solid coke and lower boiling hydrocarbon products which are suitable as feedstocks to other refinery units for conversion into higher value transportation fuels. The process thermally cracks the long chain hydrocarbon molecules in the residual oil feed into shorter chain molecules leaving behind the excess.
For the commercial delayed coking process, the high mixture velocity at the. Paul of great lakes carbon corporation of port arthur, tx. The paper aims to revisit and discuss an application of advanced process control completed 7 years ago at a delayed coking unit at the agip petroli gela refinery. The coker feedstock is heated in the coker furnace and led to the coker drums where coking takes place and the vaporous effluence are passed to a fractionator from which the heavy gas oil fraction is removed as product. The melaka coker high value apc application not only improves the unit economics but also makes operator life more comfortable, and in our opinion reducing the chance of incidents. The delayed coking process is very labor intensive. Therefore, brief descriptions of each of the processing steps preceding the delayed coking unit are provided below. This cracks the long chain heavy carbon and hydrogen molecules of the residual oil into coker gas oil and pet coke. The process involves adding small amounts of cracking catalyst and hydrogen to the hydrocarbon feedstock before it is charged to the coking drum. The delayed coker unit is basically a tertiary unit for producing value added products such as petroleum cokepetcoke.
Hazards of delayed coker unit dcu operations august. The unit takes vacuum resid fresh feed, heats it and injects it into the main fractionator bottom, where it is mixed with an internal reflux recycle of heavy cracked material. The following specific operations and more general situations and conditions contribute most. Figure 3 shows the process flow diagram of a delayed coking unit. Results show that the flow pattern in the pilot unit furnace changes from. As a result of researchers prior work, a process model was developed that, with additional work, could be used to optimize existing delayed cokers over a wide range of potential feedstocks and operating conditions. Furthermore, implementing advanced process control apc on a delayed cooker is difficult. The pfd depicts a very simplified two drum delayed coker, showing the major equipment, flow lines, and valves and the coke drum schematic illustrates a few vital parts of the coke drumstable topdrill derrick. The total fresh and recycled feed is then heated implementing coker advanced process control. Fundamentals of delayed coking joint industry project. In addition to the delayed coker knowledge within the apc team we are grateful for help from melaka process engineering, as well as from the coker operation department. In the training module on the delayed coker unit process, a typical coking and decoking process cycle is explained with detailed animation in a step by step sequence.
Multilayered strategy featuring different technologies working in synergy mpc, neural networks, spc, etc. Hazards of delayed coker unit dcu operations august 2003. The objective of the coker is to process the asphaltlike material to produce higher value products, such as gasoline, diesel fuel, lpg, and petroleum coke. Coke fines generated in the delayed coker asphaltene precipitation and agglomeration inorganic bitumen silt which is a result the oil recovery process fcc fines. This cracks the heavy, long chain hydrocarbon molecules of the residual oil into coker gas oil and petroleum coke. This presentation provides an overview of the delayed coking system found in. The delayed coker unit animation describes the coking process in a step by step manner. Pdf advanced control of the delayed coking unit in. Oil refining industryenergy recovery at a delayed coker unit. Delayed coker advanced process control at petronas melaka. The presentation has been designed for those professionals who are interested in the operation, process engineering, technical support or design of a delayed coking unit. A delayed coker is a type of coker whose process consists of heating a residual oil feed to its. Delayed coker feed material 8 delayed coker coker feedstock is material from the refinery vacuum unit, which is otherwise used as road asphalt.
Delayed coking is a key technology for residue upgrading or zero fuel oil production. The coker cracks converts the asphaltlike feedstock to a combination of products for further processing to gasoline and diesel feedstock, a coallike material called petroleum. The coker feedstock is heated in the coker furnace and led to the coker drums where coking takes place and the vaporous effluence are passed to a fractionator from which the heavy gas oil. Latest advances of the sydec delayed coking technology miguel i.
Conditions in the coker operations in any refinerys delayed coking unit are extremely severe, perhaps the harshest of any refinery operation. Dec 26, 2016 the delayed coker unit is basically a tertiary unit for producing value added products such as petroleum cokepetcoke. Despite the advent of fracking technologies and the production of lighter. Delayed coking fundamentals colorado school of mines. Delayed coking process design, operations and optimization. An introduction to delayed coking coking 101 process. Delayed coker overview a delayed coker or delayed coking unit also called a dcu or coker is a refinery unit employed to process the heaviest components of crude oil. The application had some remarkable features, including. The catalyst settles out in the coke and does not affect the utility of the coke. Delayed coking is one of the unit processes used in many oil. However, neither epa nor osha control this information and cannot guarantee the accuracy, relevance, timeliness or completeness of all facets of the information. Coking is a refinery unit operation that upgrades material called bottoms from the atmospheric or vacuum distillation column into highervalue products and, as the name implies, produces petroleum coke a coallike material.
Advanced control and optimization techniques extensively use coker models. The flow diagram and description in this section are based on a delayed coking unit with a single pair of coke drums and one feedstock furnace. This is done through a process called cracking, and involves using heat and pressure to break down long chains of hydrocarbons into shorter chains. A delayed coking process having improved liquid yield and liquid product distribution relative to coke yield is characterized by the absence of heavy recycle. A delayed coker or delayed coking unit also called a dcu or coker is a refinery unit employed to process the heaviest components of crude oil. Flow diagram and process description the schematic process flow diagram and description in this section are based on a typical delayed coking unit with two coke drums.
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