Request: Operating procedures for 3.5 million tons/year delayed coking

http://bbs.hcbbs.com/viewthread.php?tid=201220&highlight=%D1%D3%B3%D9%BD%B9%BB%AF%B2%D9%D7%F7%B9%E6%B3%CC http://bbs.hcbbs.com/viewthread.php?tid=61640&highlight=%D1%D3%B3%D9%BD%B9%BB%AF%B2%D9%D7%F7%B9%E6%B3%CC It’s not 3.5 million tons per year, but it might still be useful to you.

http://bbs.hcbbs.com/viewthread.php?tid=61640&highlight=%BD%B9%BB%AF%B2%D9%D7%F7%B9%E6%B3%CC It’s available here too

Bro, you’re not turned into a tower, are you? . .

Where is the coking capacity 3.5 million tons?

These are what I found; they might be useful to you. 258. What is included in the defocusing cycle? Answer: There are several procedures such as switching, steam injection, water cooling, water discharge, opening the cover, coke cutting, closing the cover, pressure testing, preheating, and switching. 259. What is the effect of the temperature in the coke tower on the sulfur content of coke? Answer: When the temperature of the coke tower increases, more low-sulfur heavy oil evaporates from the tower, so the sulfur content in the coke increases accordingly. 260. What is the purpose of adding an antifoaming agent to the coke tower? Answer: Adding a defoamer can reduce the foam height and minimize foam entrainment. After adding the additive, the foam thickness can be reduced from 4 m to around 1 m, improving the processing capacity of the unit and thereby increasing the volume utilization rate of the coke tower. 261. What is the operating temperature for coking reactions? Answer: It generally refers to the outlet temperature of the coking heater or the top temperature of the coke tower. 262. What is the impact of the operating temperature of the coke tower on the product? Answer: When the operating pressure and recycle ratio are fixed, increasing the temperature of the coke tower will increase the yields of gas and naphtha, reduce the yield of gas oil, and decrease the volatiles in the coke. However, excessively high temperatures in the coke tower can easily lead to foam entrainment and promote the formation of pellet coke. It increases the hardness of coke, making coking difficult. Excessively high temperatures also increase the tendency for coking in the heating furnace tubes and oil transfer lines, affecting the operational cycle. If the temperature of the coke tower is too low, the coking reaction will not be complete, resulting in the formation of soft coke or pitch. During operation, the temperature of the coke tower is used to control the volatile content of the coke. 263. What is the operating pressure in coking reactions? Answer: It refers to the pressure at the top of the coke tower. 264. What is the impact of pressure on the distribution of coking products? Answer: Once the operating temperature and recycle ratio are fixed, increasing the operating pressure leads to an increase in the amount of heavy hydrocarbons retained in the coke within the tower, as well as a longer residence time for the gaseous products in the tower. This increases the likelihood of secondary cracking reactions, thereby raising the yield of coke and slightly increasing the yield of gaseous products. Meanwhile, the yield of liquid products with a molecular weight of C5 or higher decreases, and the volatile content of the coke also increases slightly. 265. What are the measures to shorten the coke cleaning cycle? Answer: Increase the furnace outlet temperature in the final hours before switching the coke tower to reduce the time required to warm it up ； Increase the capacity of the emergency cooling water pumps and the capacity of the drainage system (but pay attention to changes in the temperature gradient for cooling in order to reduce cooling stress) ； Reduce the time required for loading and unloading the caps at the bottom of the coke tower ； Reduce coke cleaning time, improve spraying performance, and enhance coke cutting tools ； High-temperature ball valves or wedge plug valves are used for the switching valves in coke towers to reduce pressure drop. 266. What are the main problems in the operation of coke towers? Answer: To increase the processing capacity by shortening the operating cycle of the coke tower, the stress on the tower increases, which in turn reduces its service life ； Rapid cooling to meet the need for shortened cycles leads to localized overheating and localized undercooling. Stress issues not considered in the establishment of cooling times ； The different expansion coefficients of coke and the tower cause the tower to deform and its diameter to increase ； Poor preheating often leads to stress concentration, which increases the stress at the tower skirt and causes cracks. 267. What is the purpose of the venting system? Answer: To control pollution and improve gas yield. 268. What is the function of the coke treatment system? Answer: The coke and water discharged during the coking removal process are collected and separated, with the coke being sent out as a finished product. The separated coke-containing wastewater is recycled after sedimentation and separation. 269. What are the most commonly used methods for coke dehydration and storage and transportation? Answer: Direct loading, charging in coking pits, charging in coke storage pits, dehydrating tanks. 270. What is hydraulic coking removal? Answer: Hydraulic coking removal involves using high-pressure water with a pressure of 14–28 MPa, along with specialized cutting tools, to remove the coke from within the coke tower. 271. What are the equipment used for hydraulic coking removal? Answer: Drill pipes, cutting components (initial cutting components, final cutter components) 272. What are the different types of hydraulic coking removal methods used in China’s existing delayed coking units? Answer: There are three types: full derrick, semi-derrick, and derrickless. 273. How is the new type of coking removal equipment operated? Answer: First, use an initial cutter to cut a guide hole with a diameter of about 750 mm in the coke layer. The rotation speed of the drill pipe is 2–4 r/min. After cutting the guide hole, lift the drill pipe. Then, the final cutting tool assembly was installed, and the coking was cut step by step to increase the diameter of the central hole in the tower. The thickness of each cut of coke depends on the diameter of the coke tower and the amount of coke inside it. Generally, with each defocusing operation, the diameter of the central hole increases by about 0.6–1.2 mm (meaning that the thickness removed per defocusing step is 0.3–0.6 mm). The nozzle remains perpendicular to the coke layer at all times, and the water jet is emitted vertically toward the coke until, in the case of the last layer, it is directed vertically toward the tower wall. 274. Under the time-temperature conditions in the coke tower, how do the asphaltenes, resins, and aromatics in residual oil form coke? Answer: Suspensions of asphaltenes and resins undergo disproportionation to form amorphous coke with a cross-linked structure. Aromatics undergo coupling and condensation reactions to form coke. 275. What are the ways to extend the service life of the coke tower in terms of operation? Answer: The cooling method for the coke tower adopted to reduce stress is to start with a low flow rate and gradually increase the water usage. The \"immersion cooling\" method should not be used for cooling coke towers. Increase the preheating temperature to >315°C. 276. What is the process for loading coke into the storage tank? Answer: The coke and water discharged during the coking removal process are sent through chutes into a concrete-made coke storage tank. There is a water collection pit on one side of the tank; the flowing water passes through some removable baskets that collect the coke present in the water. Circulating water is used to wash the coke powder in the collection pit, and a slurry pump is employed to remove the slurry from this pit. The clean water resulting from this process is then sent to a coking removal water tank for reuse. The dehydrated coke in the coking tank is loaded onto vehicles for transportation using an overhead grab crane. 277. In the delayed coking process, how do the thermal conversion reactions of residue take place? Answer: It is carried out in three steps. The first step: The crude oil is heated to 450–510°C in a heating furnace in a very short time, during which a small amount of the crude oil vaporizes and undergoes mild catalytic cracking. Step 2: The crude oil, which has been partially cracked and comes out of the heating furnace, enters the coke tower. Based on the process conditions in the coke tower, the flow inside the tower is a gas-liquid mixture, and the oil and gas continue to undergo cracking within the tower. Step 3: The liquid heavy hydrocarbons in the coke tower undergo continuous cracking and condensation reactions under the temperature and time conditions within the tower, until hydrocarbon vapors and coke are produced. 278. What are the coking methods currently used in petroleum refining? Answer: Drum coking ； Open-hearth coking ； delayed coking ； Contact coking ； Fluidized coking. 279. What determines the height of a coke tower? Answer: It is determined based on the amount of coke produced per cycle. 280. What is CGO? Answer: It refers to coker gas oil, which is known as coker wax oil in China; it generally denotes coker distillates with a boiling point range of 350–500. 281. What is VGO? Answer: Straight-run vacuum gas oil (VGO) 282. What is the difference between VGO and CGO? Answer: The main difference is that CGO has higher levels of sulfur, nitrogen, aromatics, and resin, as well as a higher carbon residue value, whereas its saturated hydrocarbon content is lower and its polycyclic aromatic hydrocarbon content is higher. All these factors are detrimental to catalytic cracking operations, especially the nitrogen content in CGO, which reduces conversion rates and gasoline yields. 283. What is the main difference between a coking fractionation tower and an atmospheric distillation tower? Answer: The feed oil for the fractionation tower enters the tower from the lower part of its washing section; the feed is preheated in this washing section, and the coke particles present in the oil gas coming from the coke tower are removed. 284. What is the cycle ratio? Answer: It is the ratio of the circulating oil volume to the volume of fresh feed oil. 285. What is the combined cycle ratio? Answer: The combined cycle ratio = (amount of fresh feed oil + amount of recycled oil) / amount of fresh feed oil. 286. What is the effect of an increased cycle ratio on the product distribution? Answer: An increase in the circulation ratio can increase the yields of coking gas and diesel, while reducing the yield of coking wax oil. The yields of coke and coking gases increase. 287. How to reduce the circulation ratio? Answer: The circulation ratio has a direct impact on the dry point of coker wax oil. In practice, the circulation ratio is generally reduced by increasing the dry point of coker wax oil. 288. What is the effect of reducing the cycle ratio? Answer: With the capacity of the coking heater fixed, reducing the circulation ratio can increase the processing volume of fresh feedstock. However, when the recycle ratio is < 0.25, the temperature at the bottom of the main distillation column may rise above 400°C; at this point cracking and condensation reactions occur, leading to coking at the column bottom. Reducing the cycle ratio can lower coke yield and increase the yield of liquid products; as the dry point of coker wax oil rises and its yield increases, its quality decreases accordingly.

Is 400 okay? I have 400

Reply to 3# rockbo: It seems there are always errors when extracting the second part, so it can’t be used.