The schematic flow diagram below depicts a typical delayed coker. Reference 5 presents apc implementation at a delayed coking unit in khartoum refinery. Pdf advanced control of the delayed coking unit in. Delayed coking capacity has increased greatly in recent years, mostly due to the heavier crude slates being used in refineries. Although delayed coking is an old process, there are many challenges associated with it, especially as crude slates continue to change and greater throughput is. In addition to the revamp of an existing residue fluidized catalytic cracker, srip involved installation of five new units at the refinery, including an 82,000bd crude distillation unit, vacuum distillation unit, delayed coker, hydrocracker, and bitumenblowing unit. Delayed coker units in india delayed coker units dcus in india are built in extreme ambient. For the purpose of illustrating the operating cycles, figure 3.
In the next section figure 3 and figure 4, the temperaturepressure profile, will then be utilized to describe the basic process in an. Because there is so much equipment used to perform coke drum operations, to decoke the drums, and the nature of the cracked resid is to turn solid at lower temperatures and velocities, this area of the refinery stereotypically has a. Coke formation in coke drum of a delayed coking unit. Oil refining industryenergy recovery at a delayed coker unit. Hazards of delayed coker unit dcu operations showing 14 of 8 pages in this text. The next generation of switch valves for delayed coker service. Pdf advanced control of the delayed coking unit in khartoum. A pumparound heat exchange will be used to remove heat from the fractionator.
Page 1 delayed coker unit dcu introduction delayed coker unit is largestest of its type among all iocl plants in india. Wo1999060075a1 improved delayed coker unit furnace. Jul 09, 2010 houston, july 9, 2010 conocophillips nyse. Patented innovation schuf is the inventor of the lift plug valve. We would appreciate hearing from you about this document. East china university of science and technology date. These include the addition of electric, hydraulic and. However, inorganic solids are not as typical and it is the interaction of the. Schuf valves for delayed coker systems pb1010907 revision 1. In one such study the source of chloride in coker distillation column was identified to be the desalter drain water containing soluble mg and ca chlorides which was added to the slop.
Since its invention schuf has continued to develop the valve, with many innovations. The objective of this paper is to compare the prediction capability of different correlations for calculating delayed coking yields. Total investment is a primary concern for most refinery upgrade projects. Feed to coking unit is heavy hydrocarbon from bottom of different units and also includes slop. The effects of pressure, feed type, and temperature on product yields were analyzed. The return bend elbow fittings 18 connecting straight sections 16 of adjacent tubes in a delayed coker furnace are improved by subjecting the interior surface of the fittings to a diffusion hardfacing process. The proponent proposes the construction and operation of a delayed coker complex equipped with a small integrated crude oil fractionation unit, a distillate hydrotreater, and assorted utilities in come by chance, northwest of the existing refinery. When the two processes are compared, the investment cost per barrel of installed capacity for a delayed coker is usually lower than an ebullated bed. Becht knowledgeondemand series turndown fired equipment pdf. Manipulation of coker operations to avoid shot coke production is typically not economically advantageous for the refiner because of the resultant loss of liquid yield and coker throughput. 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.
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. See the complete equipment and unit turndown and shutdown series of topics as part of oracle from becht, the global engineering knowledgeondemand platform for the energy, process and power industries. Analysena, mg and ca chloride in vacuum residue water 4. There are three types of cokers used in oil refineries. Mcdermott awarded epc contract for delayed coker unit for. Comparison of correlations for estimating product yields.
Pdf process flow determines coker heater performance. Preventing emissions in coke removal digitalrefining. The condensation reactions that give rise to the highly aromatic coke product also tend to retain sulfur, nitrogen, and metals, so that the coke is enriched in these elements relative to. Delayed coking units fractionate the coke drum overhead products into fuel gas low molecular weight gases up. Recently, a new type of morphology, called transition coke, has been described, but this morphology. Crude and vacuum distillation delayed coker fluidizedbed catalytic cracker fcc alkylation hydrotreating hydrogen plant blending delayed coker is the second unit in this sevenstep overview of refining. Industrial mechanical equipment operation and maintenance training courses include stepbystep general procedure for installation, assembly and dismantling. Eil has already licensed five grass roots delayed coker units and. Delayed coker feed material delayed coker coker feedstock is material from the refinery vacuum unit, which is otherwise used as road asphalt. Decoking, however, was still a manual job accomplished by using. All equipment including the coke cutting systems have to meet these requirements. The delayed coker process is a batch process, one of the most hostile environments in the refinery due to the abrasive and erosive properties of the coke byproduct and crucial to a refinerys profitability. The process thermally cracks the long chain hydrocarbon molecules in the residual oil feed into shorter chain molecules leaving behind the excess carbon in the form of. Delayed coker free download as powerpoint presentation.
Delayed coking is the technology most used to upgrade vacuum residue into highvalue products, but in this process, secondary reactions produce coke. The delayed coking unit is the main converter of residue and usually a refinery that owns a coker is considered to be residual free sawarkar et al. A study for the implementation of an economic optimization of. 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. Narl fuels lp summary of environmental assessment process. Delayed coking is one of the unit processes used in many oil. Popwasher case study use on delayed coker unit dcu martinez, ca a refinery owner needed a safer, faster, and better method to breakout their critical path dcu flanges. Eil has experience in process design and engineering for both open art and licensed units.
Delayed coking process design, operations and optimization. F in a highly optimized unit design thermal cracking in the fired heater has been reported to be as low as 680. The nature of the delayed coking process virtually dictates that organic fines will be present either because of 1 feedstock composition, especially in the delayed coking process or 2 coke attrition, especially in the fluid coking and flexicoking processes. Delayed coker feed originates from the crude oil supplied to the refinery. Refining community chevron coker safety and reliability. 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. Coking process technologies available commercially differ in the type of reactor used and fall into two main categories. This cracks the heavy, long chain hydrocarbon molecules of the residual oil into coker gas oil and petroleum coke. Come by chance refinery delayed coker project proponent. A typical schematic flow diagram of a delayed coking unit. The delayed coker unit is basically a tertiary unit for producing value added products such as petroleum cokepetcoke. Delayed coking was the first type of coker introduced in the refining market place. A reference list is available upon request the first switch valve built to our design was installed in 1983.
Valves are cycled frequently and failure can lead to a complete shutdown of a unit, resulting in large process and financial costs. Dec 26, 2016 the delayed coker unit is basically a tertiary unit for producing value added products such as petroleum cokepetcoke. 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. The process itself and decoking methods can cause erosion to the tubes and especially the ubends. The complete bidding document for above mentioned mrtender are. The preowned delayed coker unit belongs to an entire package, consisting of a crude distillation unit, vacuum unit and a hydrogen production unit with psa. While delayed coking is simple enough, the cyclic nature of the process gives ample scope to the talents of the troubleshooter. The process configuration of a delayed coking unit resembles that of visbreaking figure 5.
Delayed coker operators with a pitpad system have made efforts, together with mechanical equipment suppliers, to improve the mechanical steps in the process, in particular with installation of top and bottom unheading equipment. Once removed from the coke drums, the coke is transported away from the receiving area. From here, the coke is either exported from the refinery or crushed, washed, and stored prior to export. Although delayed coking is an old process, there are many challenges associated with it, especially as crude slates continue to change and greater throughput is required of delayed coking units. Wo1999060075a1 pctus1999007353 us9907353w wo9960075a1 wo 1999060075 a1 wo1999060075 a1 wo 1999060075a1 us 9907353 w us9907353 w us 9907353w wo 9960075 a1 wo9960075 a1 wo 9960075a1 authority wo wipo pct prior art keywords fittings furnace delayed coker coker unit return bend prior art date 19980515 application number. Oct 29, 2015 oil refining industryenergy recovery at a delayed coker unit. The delayed coking complex will be built at the 17 milliontonyear kstovo refinery in central russias nizhny novgorod region. Industrial maintenance training plant operator training. 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.
To understand the delayed coking process, one must understand how the delayed coker is integrated with the rest of the refinery. This unit uses vacuum residue obtained from fractionation as the feed the main objective of this unit is to separate out middle distillates, and give products such as lpg and naphtha. This part of the presentation will explore a refinerys experience with coker furnace tube thinning that was unusual compared to typical damage profile. The heavy feed, typically from the refinerys atmospheric andor vacuum unit, is introduced into the bottom of the fractionator vessel, t1. Work is fast and continuous, and downtime is crippling to production. The technology of choice for most of these projects has been delayed coking.
The primary focus on multimedia inputs like graphics, animation and interactivity help in very clearly understanding operating working principles and maintenance procedures. The preheated feed is flown into the bottom of the reactor, an isolated. Reliability of the structure block equipment is covered in the delayed coker operations and reliability training, a twoday course offered at refcomm budapest. A basic refinery flow diagram is shown on the following page in figure 1. Pdf delayed coking units convert heavy crude oil or topping refinery. Research pdf available january 2014 with 412 reads. Unit ontime capacity has been increased, contributing to the units cash flow. 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. Title link to download bidding document bidding document. Our delayed coker unit fractionator boot water chloride. Paul of great lakes carbon corporation of port arthur, tx. Schematic diagram of delayed coker unit to gascon section salient features minimization of shot coke formation by parametric and feedstock quality adjustment. Mcdermott will provide epc for a delayed coker unit in kstovo, russia, that will process 2. Therefore, brief descriptions of each of the processing steps preceding the delayed coking unit are provided below.
The delayed coker furnace is the heart of the unit. A foam over in a delayed coker unit can be a costly event, not only causing loss of production but also requiring a lot of manual labour to clean coke out of the. On 29 february 2000, exxon mobil usa announced the start of construction of the new delayed coker at its existing baytown refinery. The one that is by far the most commonly used is the delayed coker. Thus, in the current economic environment, the coker is frequently the most important unit in the refinery. It is already known that the chemical and physical properties and composition of the feedstock and processing conditions affect coke morphology.
Delayed coker unit dcu civil engineering ce notes edurev. It is based upon a rigorous and highfidelity mathematical process model to provide a realistic dynamic response of a process unit. Page 38 the hot product vapours from the filling drums will be routed to the coker fractionator. Knowledge of commercial delayed coking units as well as that of the glc pilot delayed coker is used in. Pdf simulation of delayed coking reaction in coke drum.
This part of the presentation will explore a refinerys experience with coker furnace tube thinning that. Delayed coker unit pinch an article from linhoffmarch on how to do a pinch for delayed coker unit with examples and calulations. 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. Petroleum residue upgrading via delayed coking publications of. By far the largest amount of coking capacity is represented by the delayed coking process. See the complete equipment and unit turndown and shutdown series of topics as part of oracle from becht, the global engineering knowledgeondemand platform for the energy, process and power industries the series including high risk, high impact concerns, symptoms and consequences to evaluate during transient operations in conjunction with expert insights.
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