Preventing emissions in coke removal digitalrefining. Learning from coker heater observations analysis corrective measures feedback 02 instances of bulging and sagging of radiation section tubes size. This is a report on the hazards of delayed coker unit dcu operations. Mcdermott awarded epc contract for delayed coker unit for.
The following specific operations and more general situations and conditions contribute most. Typical feed is vacuum resid atmospheric residoccasionally used. The delayed coker process is a batch process, one of the most hostile environments in the refinery due to. A delayed coker is a type of coker whose process consists of heating a residual oil feed to its. Advanced control of the delayed coking unit in khartoum. 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. Delayed coker upgrades low value residual fuel into higher value light products rum total coker unit liquid volume yield is approximately 80% of throughput. Therefore, brief descriptions of each of the processing steps preceding the delayed coking unit are provided below. Delayed coking fundamentals pdf prepared by paul j. Delayed coker is the second unit in this sevenstep overview of refining. However, neither epa nor osha control this information and cannot guarantee the accuracy, relevance, timeliness or completeness of all facets of the information. There are two kinds of coke produced by delayed coking of vdr. Eil is jointly licensing the delayed coker technology by.
Technology for refinery professionals delayed coking unit. Photograph of a 4drum delayed coking unit in a benica petroleum refinery in california. The first phase was the greenfield assembly of the smaller modules into larger modules groups of 24. Cracking begins in the furnace, continues in the transfer line, and finishes in the coke drum. This presentation provides an overview of the delayed coking system found in.
In delayed coking, the process is designed so that the coke forms in a drum. Pdf uniform tube metal temperature resulting from a change in process flow enhances the run length of a delayed coker heater. Consultant expert witness lng liquefied natural gas. Advanced control and optimization techniques extensively use coker models. On 29 february 2000, exxon mobil usa announced the start of construction of the new delayed coker at its existing baytown refinery. Valves are cycled frequently and failure can lead to a complete shutdown of a unit, resulting in large process and. 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 is a type of thermal cracking in which the heat required to. Delayed coking process and a photograph of a delayed coking unit. 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. Pdf delayed coking units convert heavy crude oil or topping refinery residue to more light valuable products including diesel, gasoline and naphtha by.
Maintaining a safe, healthy environment around the coker is critical. The fractionator tower also known as the main fractionator or combination tower receives the unit feed and the overhead hot vapors from the coking drum in the bottom tower section. A refinery built to specialize in light sweet, for example, may not be able to handle heavy sour. Basics of refining and optimization valero energy corp. Advanced control of the delayed coking unit in khartoum refinery tomadir a. Typical feed composition 6% sulfur 1,000 ppmwt metals. Revisiting advanced process control on a delayed coking unit. Water cutting valves handle suspended coke fines in recycled feed water under high pressure of 3500 to 5000 psi that erode components. Delayed cokers can convert even the heaviest residues to lighter distillates provides much needed flexibility to the refiners to process a wide variety of crude oil and therefore, is the most widely used process all over the world. Paul of great lakes carbon corporation of port arthur, tx. The delayed coker unit animation describes the coking process in a step by step manner. There are two types of coking processes, fluid cokers and delayed cokers. Refineries are designed to process only particular ranges of crude. Hazards of delayed coker unit dcu operations august 2003 pdf.
All valve sizes and classes shown in this brochure have been designed and built and are currently installed and operating in a delayed coker unit. 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. Pdf process flow determines coker heater performance. Delayed coker feed originates from the crude oil supplied to the refinery. 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. This interactive tutorial provides an overview, fundamental principles, and control and operating principles for a delayed coker unit using voice, video, animation and graphics.
Sep 17, 2017 the delayed coker unit animation describes the coking process in a step by step manner. Support facilities include closed blowdown, coke cutting and handling, and a water recovery system. In the training module on the delayed coker process, a typical coking process and decoking cycle operation. In its simplest terms, delayed coking is a semibatch thermal cracking process using alternating drums that are switched offline after filling. Water cutting valves handle suspended coke fines in recycled feed water under high pressure of 3500 to. The total fresh and recycled feed is then heated implementing coker advanced process control. Delayed coking is one of the chemical engineering unit processes used in many petroleum refineries. In the next section figure 3 and figure 4, the temperaturepressure profile, will then be utilized to describe the basic process in an. This cracks the heavy, long chain hydrocarbon molecules of the residual oil into coker gas oil and petroleum coke delayed coking is one of the unit processes used in many oil refineries. Despite the advent of fracking technologies and the production of lighter. Overview introduction importance of delayed coking process overview delayed coking process components. In addition to the delayed coker, the complex will include a diesel hydrotreater, gas fractionation unit, sulfur and hydrogen production units, and associated systems. Refinery overhead plants management aims at saturating both coking units, by adapting other units downstream and upstream to reach this goal.
Hazards of delayed coker unit dcu operations august 2003. You may need a pdf reader to view some of the files on this page. Hazards of delayed coker unit dcu operations august. The delayed coking process is a thermal process and consists of fired heaters, coke drums and a main. Compounding the hazards of the process itself are the low visibility, highnoise environment and even the weather. 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. Delayed coker advanced process control at petronas melaka. We would not recommend that anyone begin coker apc work without such support as the coker is a demanding unit, and. Coking is the primary process used to upgrade petroleum residues. Delayed coking is one of the unit processes used in many oil. 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 one that is by far the most commonly used is the delayed coker. 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.
Delayed coker feed material delayed coker coker feedstock is material from the refinery vacuum unit, which is otherwise used as road asphalt. One of these conversion methods is the delayed coker unit dcu. Biomassto liquid btl congress, berlin scroll down to pdf page 9 of 21 pdf pages. The feed to coker is usually vacuum residue which is high on asphaltenes, resins, aromatics.
Attend delayed coker operations and reliability training or delayed coking process, design and troubleshooting training courses. This cracks the heavy, long chain hydrocarbon molecules of the residual oil into coker gas oil and petroleum coke. A reference list is available upon request the first switch valve built to our design was installed in 1983. Advanced control of the delayed coking unit in khartoum refinery. A 4drum delayed coking unit in a petroleum refinery. Delayed coking process design, operations and optimization. Also at check out coker process, design and troubleshooting taught by. The return bend elbow fittings connecting adjacent tubes in a delayed coker furnace are improved by subjecting the interior surface of the fittings to a diffusion hardfacing process.
Dec 26, 2016 the delayed coker unit is basically a tertiary unit for producing value added products such as petroleum cokepetcoke. Delayed coker unit process animation yes yen graphitech. Wo1999060075a1 improved delayed coker unit furnace. Pdf advanced control of the delayed coking unit in khartoum. Coking process technologies available commercially differ in the type of reactor used and fall into two main categories. This cracks the long chain heavy carbon and hydrogen molecules of the residual oil into coker gas oil and pet coke. Dependable eim electric actuators improve delayed coker. 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. The product obtained from this unit is commonly known as petroleum coke which serves as the feed for a number of different applications.
The project was initiated in november 1998 when exxon mobil awarded the contract to provide conocolicensed delayed coking technology for two of exxons refineries, to the conocobechtel coker technology alliance, a business unit of the bechtel corporation. Delayed coker free download as powerpoint presentation. Delayed coking products and services bottom and top unheading valves retractable center feed injection devices. An introduction to delayed coking coking 101 process. Unlike the other processing units in the refining business, delayed coking. The yield slate for a delayed coker can be varied to meet a refiners objectives through the selection of its operating parameters. Baytown refinery coker facility, tx hydrocarbons technology. The heavy feed, typically from the refinerys atmospheric andor vacuum unit, is introduced into the bottom of the fractionator vessel, t1. Thermal stability of the heavy oil in the vacuum unit make it difficult to cut deep. Isolation valves for coking service valvtechnologies. 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. 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. Anything that can be done to increase reliability, lower.
A typical schematic flow diagram of a delayed coking unit. Hazards of delayed coker unit dcu operations, the batch portion of dcu drum switching and. Coker unit operators appreciate reliable automation application operating ball valves, water purge and slurry gate valves on delayed coking unit process valving. This process produces a solid coke which has a high carbon content. The heating in the delayed coker unit operation, cracks the long chain heavy carbon and hydrogen molecules to facilitate the coking process. From here, the coke is either exported from the refinery or crushed, washed, and stored prior to export. This results in excessive amounts of gas oil being sent to the delayed coker. Delayed coking produces 19% of finished product exports according to eia. 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 coking has an increasingly important role to play in the integration of modem petroleum refineries, as the process can handle even the heaviest of residues.
The delayed coker unit dcu is among the most dangerous operating areas within the refinery. The preheated feed is flown into the bottom of the reactor, an isolated. To understand the delayed coking process, one must understand how the delayed coker is integrated with the rest of the refinery. Inlet temperatures of the residual oil flowing from the fractionator through the transfer line into the coke drum exceed 800f 425 c at low pressures of 1015 psig. The adjacent photograph depicts a delayed coking unit with four coke drums two pairs of two drums.
Delayed coking fundamentals colorado school of mines. The gas can also be used in the alkylation unit because of its high olefin content. Internet resources the search entry, delayed coker unit, yields many sources of information that are believed to be useful. In the training module on the delayed coker process, a typical coking. Delayed coking was the first type of coker introduced in the refining market place. In 2011 a major south american oil and natural gas plant suffered significant.
Delayed coking process design, operations and optimization may 2012 canada coking conference october 2226, 2012. Customer louisiana lake charles refinery complex, lake charles, louisiana, usa challenge operating conditions in any refinerys delayed coker units are extremely severe. Knowledge of commercial delayed coking units as well as that of the glc pilot delayed coker is used in. Hazards of delayed coker unit dcu operations august 2003 once removed from the coke drums, the coke is transported away from the receiving area. Conditions in the coker operations in any refinerys delayed coking unit are extremely severe, perhaps the harshest of any refinery operation. Hazards of delayed coker unit dcu operations unt digital. There are three types of cokers used in oil refineries.