What is the most advanced oil refining process?

Introduction to Major Refining Processes: Atmospheric Distillation and Vacuum Distillation. Atmospheric distillation and vacuum distillation are commonly referred to together as atmospheric-vacuum distillation; this process is essentially a physical one. In the distillation tower, crude oil is separated into different oil fractions with varying boiling points based on their evaporation capacity. Some of these fractions are blended and enhanced with additives before being sold as finished products, while a large portion of them serve as raw materials for further processing units. Therefore, atmospheric and vacuum distillation is also referred to as the primary processing of crude oil. It includes three processes: desalination and dewatering of crude oil ； atmospheric distillation ； Vacuum distillation. 　　 Desalination and dewatering of crude oil, also known as pretreatment. Crude oil transported from oil fields to refineries often contains salts (mainly chlorides) and water (either dissolved in the oil or in an emulsified state), which can cause equipment corrosion, lead to scaling on the inner walls of the equipment, and affect the composition of the refined oil; therefore, it needs to be removed prior to processing. The common method is to add demulsifiers and water, which causes the water in the oil to aggregate and separate from it; the salts dissolve in the water. Along with the application of a high-voltage electric field, this helps to remove the larger water droplets that are formed. 　　Catalytic cracking Catalytic cracking was developed from the thermal cracking process. It is the most important process operation for increasing the degree of crude oil processing and producing high-quality gasoline and diesel. The feedstock is mainly heavy oil from the 350–540°C fraction of crude oil distillation or other refining units. The catalytic cracking process consists of three parts: catalytic cracking of the feedstock oil, catalyst regeneration, and product separation. The products obtained from catalytic cracking can be separated by distillation to yield gas, gasoline, diesel, and heavy distillates. Some of the oil returns to the reactor for further processing, which is known as recycled oil. Changes in the operating conditions of catalytic cracking or fluctuations in feedstock can cause variations in the product composition. 　 　Catalytic reforming 　　 Catalytic reforming (abbreviated as reforming) is a process in which light gasoline obtained through atmospheric distillation is converted into reformate gasoline with a higher content of aromatics, in the presence of a catalyst and hydrogen. If fractions at 80–180°C are used as raw materials, the product is high-octane gasoline ； If distillates at 60–165°C are used as the feed oil, the products are mainly aromatics such as benzene, toluene, and xylene; hydrogen is produced as a by-product of the reforming process, and this hydrogen can be used as a source for hydrogenation operations in refineries. The reaction conditions for reformation are: a reaction temperature of 490–525°C, and a reaction pressure of 1–2 MPa. The reforming process can be divided into raw material pretreatment and reforming. 　 　 Hydrocracking is carried out under high pressure in the presence of hydrogen, and a catalyst is required to convert heavy feedstocks into gasoline, kerosene, diesel, and lubricating oils. Due to the presence of hydrogen in hydrocracking, less coke is formed during the conversion of raw materials, and harmful compounds containing sulfur, nitrogen, and oxygen can be removed. The process is flexible and can be adjusted according to the requirements of the desired products. The product yield is high, and the quality is good. 　 　Delayed coking: It involves the deep cracking of feedstock over a prolonged reaction time, with the main objective of producing solid petroleum coke, while also generating gaseous and liquid products. The feedstock for delayed coking is mainly high-boiling-point residue oil. The main operating conditions for delayed coking are: the temperature of the feedstock after heating is around 500°C, and the coke tower operates under slight positive pressure. Changing the raw materials and operating conditions can adjust the proportions of gasoline, diesel, cracking feedstock oil, and coke. 　 　Refinery gas processing: All the production units involved in the primary and secondary processing of crude oil generate gases, which are collectively referred to as refinery gas. In terms of their composition, these gases mainly include hydrogen, methane, ethane and ethylene composed of 2 carbon atoms, propane and propylene composed of 3 carbon atoms, and butane and butenes composed of 4 carbon atoms. Their main uses are as raw materials for producing gasoline and petrochemicals, as well as for producing hydrogen and ammonia. The prerequisite for developing refinery gas processing is to first separate and then utilize the refinery gas. The proportion of refinery gas that is separated for use as chemical raw materials is increasing; for example, purer ethylene can be obtained for use in the production of ethylbenzene ； The purer propylene can be separated out for use in polypropylene and other products.

Is the hydrocracking process more advanced?

Each unit has its own characteristics; for example, in the case of refining units – atmospheric and vacuum distillation units – the focus is on increasing the yield. Previous processes are modified, such as by altering the tray design and vacuum ejectors, in order to adapt to current production requirements.

During the petroleum refining process, especially during the secondary processing steps aimed at converting heavy oils into lighter ones, large amounts of gas are generated. Apart from the hydrogen-rich gas produced by catalytic reforming, the gases produced by other units mainly consist of gaseous hydrocarbons ranging from carbon-1 (methane, CH4) to carbon-4 (butane, butylene, etc.), along with small amounts of impurities. Among these units, catalytic cracking units generate the largest volume of gas, and they also produce the highest amount of olefins in the gases. Therefore, catalytic cracking gas is the main source for refinery gas processing units. Refinery gas is usually divided into two parts; the hydrocarbons consisting of C1 and C2 compounds (ethane, ethylene) are known as dry gas. This component is present in small quantities and is generally used as fuel gas for heating furnaces. The ethylene component in the dry gas can also be utilized to produce styrene and other substances ； Hydrocarbons with three carbon atoms (propane, propylene, etc.) and four carbon atoms, namely liquefied petroleum gas, can be further processed to produce various chemical raw materials, and they constitute the main focus of refinery gas processing. The first step in processing refinery gas is to separate the various components as required, that is, through gas distillation. As for the processes involved in processing the gas after distillation, only those units that are closely related to oil refining production will be discussed here, such as alkylation, copolymerization, and methyl tert-butyl ether production.

As mentioned above, the refining process is a fairly standardized system; every refinery is composed of these same components. If we’re to talk about which processing technologies are advanced, I believe it’s the improved processes for processing heavy crude oil. Because this is also the direction in which oil refining will develop in the future, it is indeed necessary to put a lot of effort into this area.