How to distinguish the weight of catalytic raw materials?

Catalytic cracking raw materials include: 1. Straight-run vacuum distillate oil ； 2. Delayed coking distillate oil ； 3. Normal pressure residual oil ； 4. Vacuum residual oil ； 5. Deasphalted oil. Generally, raw oils are classified into light and heavy ones based on raw material density, ash content, heavy metal content, etc.

Generally speaking, the weight of catalytic raw materials depends on its density and distillation range.

At the same reaction temperature, the raw material becomes heavier, there is more oil slurry and recycled oil, and there is less dry gas and liquefied gas. At this time, we should increase the reaction temperature and increase the reaction depth. Or increase the speed of small-scale feeding to improve the activity of the catalyst. On the contrary, if the raw material becomes lighter, at the same reaction temperature, there will be more dry gas and liquefied gas, the reaction pressure will increase, and there will be less oil slurry and recycled oil. In terms of operation, we can analyze the weight of raw materials through the distribution of products, which requires long-term operation and continuous accumulation of experience. In addition, we can also look at the specific gravity of the raw materials from the laboratory analysis data, and get the weight data of the raw materials from the full distillation range analysis data of the raw materials. In short, reading more and analyzing more is the key to improvement.

It mainly depends on the distillation range, 50% and dry point, as well as metal content and carbon residue.

The raw materials for catalytic cracking generally look at the residual carbon and metal content (Ni, V). Literature shows that the residual carbon is less than 5%, the heavy metal content is less than 10/ug.g, and passivation is used for routine regeneration. ； The residual carbon is less than 10% and the heavy metal content is less than 30/ug.g. It can be completely regenerated by using passivation agent and regenerator for heat. ； The carbon residue is greater than 10% and less than 20%, and the heavy metal content is greater than 30/ug.g and less than 150. The raw materials need to be processed before they can be used for catalysis. ； The residual carbon is greater than 20% and the heavy metal content is greater than 150, making it suitable as a coking raw material. Raw materials for catalytic cracking processing generally refer to raw materials with a 538°C component of more than 5%. 1. Normal pressure residual oil, vacuum wax oil ； 2. Deasphalted oil (DAO) ； 3. Remove residual oil ； 4. Coked distillate oil (CGO) ； 5.Hydrotreated oil ；

Generally, they are distinguished based on density and carbon residue!

Judgment based on the density of raw materials, cutting process, and residual carbon. It can also be judged based on changes in operating conditions.

If the raw material becomes heavier, this will be reflected in the operation by an increase in the temperature of the regenerator and an increase in the liquid level at the bottom of the refining tank and fractionation tower.

The weight of raw materials is mainly divided by density, process, and carbon residue, and is also determined by the origin and blending volume of the raw materials. :handshake

We judge the original weight based on the specific gravity (density) of crude oil and product distribution.

The weight of catalytic cracking raw materials mainly refers to density, followed by distillation range and carbon residue.

The weight of the feed to the catalytic cracking unit is relative to each other and is mainly determined based on the raw material density, distillation range and carbon residue. For example, generally speaking, if VGO, DAO and CGO have the same distillation range, DAO will be considered heavier, VGO will be lighter, etc.

(1) Source of raw oil The range of catalytic cracking raw materials is very wide. There are 350~500℃ straight-run distillate oil, atmospheric pressure residual oil and vacuum residual oil. There are also secondary processing fractions such as coked wax oil, lubricating oil dewaxed wax paste, wax base oil, deasphalted oil, etc. 1. Straight-run distillate oil is generally normal pressure heavy distillate and vacuum distillate. The straight-run fractions of different crude oils have different properties, but the straight-run fraction contains high amounts of alkanes and less aromatic hydrocarbons (see Table 3-1), so it is easy to crack, and the light oil yield and total conversion rate are also higher. According to the situation of my country’s crude oil, straight-run distillate catalytic feed oil has the following characteristics:: (1) There are few light components in crude oil, mostly below 30%, so there is sufficient raw material for catalytic cracking ； (2) Low sulfur content and low heavy metal content. The sulfur content of most catalytic cracking raw materials is 0.1% to 0.5%, and the nickel content is generally 0.1 to 1.0 mg/kg. Only the Gudao crude oil distillate has high sulfur content and heavy metal content. ； (3) The main crude oil catalytic cracking raw materials, such as Daqing, Renqiu, etc., have high wax content, so the characteristic factor K is also high, generally 12.3 to 12.6. The above shows that my country's catalytic cracking raw materials are large in quantity and high in quality, making them ideal catalytic cracking raw materials. ⒉Table 3-2 of catalytic cracking raw materials obtained from secondary processing lists the properties of several commonly used secondary processing oils. (1) Wax paste and wax base oil dewaxed with benzene are ideal catalytic cracking raw materials that contain more alkanes, are easy to crack, and produce less coke. (2) Coked wax oil and visbroken cracked distillate oil are oils that have been cracked. They have high aromatic hydrocarbon content, poor cracking performance, and high coke yield. Generally, they cannot be used as catalytic cracking raw materials alone. (3) Deasphalted oil and raffinate oil contain more aromatic hydrocarbons, which are easy to condense and difficult to crack. Therefore, the conversion rate is low and the amount of coke is high. They can only be blended with straight-run distillate oil and used as catalytic cracking raw materials. ⒊Atmospheric pressure residue and vacuum residue Most of my country's crude oil is heavy crude oil. The yield of vacuum residue accounts for about 40% of crude oil, and the yield of atmospheric residue accounts for 65% to 75%. The amount of residual oil is large. Over the past decade, my country's heavy oil catalytic cracking has made great progress. The heavy oil catalytic cracking process was developed to increase the depth of crude oil processing and effectively utilize precious petroleum resources. The carbon residue and heavy metal content in conventional catalytic cracking feedstock oil are relatively low, while heavy oil catalytic cracking is to mix different proportions of vacuum residue oil into conventional catalytic cracking feedstock oil or directly use full-distillation atmospheric pressure residue oil. Due to changes in the feed oil, the increase in colloid, asphaltenes, heavy metals and carbon residue values, especially the change in group composition, has a great impact on the catalytic cracking process. Therefore, for heavy oil catalytic cracking, we must first solve the impact of high residual carbon value and high heavy metal content on the catalytic cracking process in order to better utilize limited petroleum resources. Table 3-3 and Table 3-4 list the properties of several atmospheric pressure residues and vacuum residues in my country. (2) Indicators for measuring the properties of raw materials The following indicators are usually used to measure the properties of raw oil. 1. Fraction composition Fraction composition can determine the weight of raw materials and the width of the boiling point range. When the chemical composition of the feed oil is similar, the heavier the fraction, the easier it is to crack. ； The lighter the fraction, the less likely it is to crack. Due to the rational utilization of resources, pure wax oil type catalytic cracking has become less and less popular in recent years. 2. Hydrocarbon composition Hydrocarbon composition is usually expressed by the content of alkanes, cycloalkanes, and aromatics. The composition of raw materials varies depending on the source of the raw materials. Paraffin-based raw materials are easy to crack, resulting in low gasoline and coke yields and high gas yields. ； Naphthenic raw materials are the easiest to crack, with high gasoline yield, high octane number and low gas yield. ； Aromatic raw materials are difficult to crack, resulting in low gasoline yield and excessive coking. It is difficult to analyze the hydrocarbon composition of heavy feed oil. It is rarely measured in daily production. This analysis is only done during device calibration. Usually, it is indirectly judged by measuring physical properties such as density, characteristic factor, and aniline point. (1) Density The greater the density, the heavier the raw material. If the fraction composition is the same, the density is high, and the content of naphthenes and aromatics is high ； The density is small and the alkane content is high. (2) Characteristic factor K Characteristic factor is related to density and fraction composition. A high K value of the raw material indicates that it contains many alkanes, and a low K value indicates that it contains many aromatic hydrocarbons (see Table 3-1). The K value of the raw material can be calculated from Engler's distillation data and density. It can also be obtained from density and aniline point lookup plots. (3) Aniline point The aniline point is an indicator of the aromatic hydrocarbon content in the oil. The lower the aniline point, the higher the aromatic hydrocarbon content in the oil. 3. Carbon residue The carbon residue value of raw material oil is one of the main indicators to measure the properties of raw materials. It is related to factors such as the composition of the raw materials, the width of the fraction and the content of gum and asphaltene. If the residual carbon value of the raw material is high, there will be more coke. The residual carbon value in conventional catalytic cracking feedstock is relatively low, generally around 6%. In the catalytic cracking of heavy oil, part of the vacuum residual oil is mixed into the raw material or the full-distillation atmospheric pressure residual oil is directly processed. As the raw material oil becomes heavier, the colloid and asphaltene content increases, and the residual carbon value increases. 4. Among the heavy metals in the metal feed oil, vanadium, nickel, iron, and copper have the greatest impact on the catalyst activity and selectivity. During the catalytic cracking reaction, vanadium electrodes are easily deposited on the catalyst. During regeneration, the vanadium is transferred to the molecular sieve position and reacts with the molecular sieve to generate a eutectic compound with a melting point of 632°C, destroying the crystal structure of the catalyst and permanently deactivating it. Nickel is deposited on the catalyst and transferred to the position of the molecular sieve, but does not destroy the molecular sieve. It only partially neutralizes the acidic center of the catalyst and has little effect on the catalyst activity. Since nickel itself is a dehydrogenation catalyst, the dehydrogenation reaction can be carried out under the temperature and pressure conditions of the catalytic cracking reaction, thereby increasing the hydrogen yield and reducing the liquid. Alkali metal sodium, calcium, etc. in the raw materials also affect the catalytic cracking reaction. The deposition of Na on the catalyst will affect the thermal stability, activity and selectivity of the catalyst. With the development of heavy oil catalytic cracking, people are paying more and more attention to the hazards of Na. Na not only causes acid poisoning of the catalyst, but also generates a low melting point sodium vanadate eutectic with the vanadium oxide deposited on the catalyst surface, which forms a molten state at the high temperature of catalyst regeneration, damaging the molecular sieve lattice and reducing activity. This degree of toxicity becomes more severe as the temperature increases (see Table 3-5). Therefore, for heavy oil catalytic cracking, the Na content of the raw material must be strictly controlled, generally controlled below 5 mg/kg. 5. Sulfur and nitrogen content Nitrogen-containing compounds in the raw materials, especially when the content of basic nitrogen compounds is high, will cause catalyst poisoning and decrease its activity. Studies have shown that when 0.1% (mass) of alkaline nitrogen compounds are added to the cracking raw material, the cracking reaction speed decreases by about 50%. In addition, basic nitrogen compounds are one of the important reasons for the discoloration of product oil and the deterioration of oxidation stability. The sulfur-containing compounds in the raw materials have no significant impact on the catalyst activity. In the test, the raw materials containing 0.35% to 1.6% sulfur were not found to have an impact on the catalytic cracking reaction rate. However, sulfur will increase equipment corrosion, increase the sulfur content of products, and pollute the environment. Therefore, attention should be paid to the sulfur and nitrogen content in raw materials and products during the catalytic cracking production process. If the content is too high, pre-refining treatment is required. (3) Products and Product Characteristics During the catalytic cracking process, when the raw materials, catalysts and reaction conditions used are different, the yields and properties of the products obtained will also be different. But in general, catalytic cracking products have many characteristics compared with thermal cracking. 1. Gas products Under general industrial conditions, the gas yield is about 10 to 20%, and the components included are hydrogen, hydrogen sulfide, and C1 to C4 hydrocarbons. The hydrogen content mainly depends on the degree of contamination of the catalyst by heavy metals. H2S is related to the sulfur content of the raw material. C1 is methane, C2 is ethane and ethylene, and the above substances are called dry gas. A large amount of C3 and C4 (called liquid hydrocarbons or liquefied gases) in the catalytic cracking gas are, among which C3 is propane and propylene, and C4 includes 6 components (n-, iso-butane, n-butene, iso-butene and cis- and trans-2-butene). The characteristics of gas products are as follows: (1) C3 and C4 account for the vast majority of gas products, about 90% (weight), with less C2 and below. There is less C3 than C4 in liquefied gas, and the C4 content in liquid hydrocarbons is about 1.5 to 2.5 times that of C3. (2) There are more olefins than alkanes. The olefins in C3 are about 70%, and the olefins in C4 are about 55%. (3) C4 contains more isobutane, less n-butane, more n-butene, and less isobutylene. The above characteristics make catalytic cracking gas a good raw material for the petrochemical industry. The dry gas from catalytic cracking can be used as fuel and as a raw material for ammonia synthesis. Since it contains some ethylene, ethylene oxide can be produced through hypochlorous acidification to produce ethylene glycol, ethylenediamine and other chemical products. Liquid hydrocarbons, especially olefins, can produce three major synthetic products such as various organic solvents, synthetic rubber, synthetic fibers, and synthetic resins, as well as various high-octane gasoline components such as superimposed oil, alkylate oil, and methyl tert-butyl ether. 2. Liquid products (1) The yield of catalytically cracked gasoline is 40 to 60% (mass). Because there are more olefins, isoparaffins and aromatics, the octane number is higher, generally around 80 (MON). Because it contains less alpha olefins among the olefins and basically does not contain dienes, its stability is also relatively good. It contains more low-molecular hydrocarbons, has lower temperatures at its 10% point and 50% point, and has good performance. (2) The yield of diesel is 20 to 40% (mass). Because it contains more aromatic hydrocarbons, about 40 to 50%, the cetane number is much lower than that of straight-run diesel, only about 35. It often needs to be blended with straight-run diesel before it can be used as diesel engine fuel. (3) Residual oil contains a small amount of catalyst fine powder and is generally not used as a product. It can be returned to the riser reactor for refining. If the catalyst is removed through clarification, some (3-5%) clarified oil can also be produced. Because it contains a large amount of aromatic hydrocarbons, it is a good raw material for the production of heavy aromatic hydrocarbons and carbon black. 3. Coke from coke catalytic cracking is deposited on the catalyst and cannot be used as a product. The coke yield of conventional catalytic cracking is about 5 to 7%. When residual oil is used as raw material, it can be as high as 10% or more, depending on the quality of the raw material. From the above product distribution and product quality, it can be seen that catalytic cracking has its unique advantages, which are incomparable with general thermal destruction processing.

(1) Source of raw oil The range of catalytic cracking raw materials is very wide. There are 350~500℃ straight-run distillate oil, atmospheric pressure residual oil and vacuum residual oil. There are also secondary processing fractions such as coked wax oil, lubricating oil dewaxed wax paste, wax base oil, deasphalted oil, etc. 1. Straight-run distillate oil is generally normal pressure heavy distillate and vacuum distillate. The straight-run fractions of different crude oils have different properties, but the straight-run fraction contains high amounts of alkanes and less aromatic hydrocarbons, so it is easy to crack, and the light oil yield and total conversion rate are also higher. According to the situation of my country’s crude oil, straight-run distillate catalytic feed oil has the following characteristics:: (1) There are few light components in crude oil, mostly below 30%, so there is sufficient raw material for catalytic cracking ； (2) Low sulfur content and low heavy metal content. The sulfur content of most catalytic cracking raw materials is 0.1% to 0.5%, and the nickel content is generally 0.1 to 1.0 mg/kg. Only the Gudao crude oil distillate has high sulfur content and heavy metal content. ； (3) The main crude oil catalytic cracking raw materials, such as Daqing, Renqiu, etc., have high wax content, so the characteristic factor K is also high, generally 12.3 to 12.6. The above shows that my country's catalytic cracking raw materials are large in quantity and high in quality, making them ideal catalytic cracking raw materials. ⒉Table 3-2 of catalytic cracking raw materials obtained from secondary processing lists the properties of several commonly used secondary processing oils. (1) Wax paste and wax base oil dewaxed with benzene are ideal catalytic cracking raw materials that contain more alkanes, are easy to crack, and produce less coke. (2) Coked wax oil and visbroken cracked distillate oil are oils that have been cracked. They have high aromatic hydrocarbon content, poor cracking performance, and high coke yield. Generally, they cannot be used as catalytic cracking raw materials alone. (3) Deasphalted oil and raffinate oil contain more aromatic hydrocarbons, which are easy to condense and difficult to crack. Therefore, the conversion rate is low and the amount of coke is high. They can only be blended with straight-run distillate oil and used as catalytic cracking raw materials. ⒊Atmospheric pressure residue and vacuum residue Most of my country's crude oil is heavy crude oil. The yield of vacuum residue accounts for about 40% of crude oil, and the yield of atmospheric residue accounts for 65% to 75%. The amount of residual oil is large. Over the past decade, my country's heavy oil catalytic cracking has made great progress. The heavy oil catalytic cracking process was developed to increase the depth of crude oil processing and effectively utilize precious petroleum resources. The carbon residue and heavy metal content in conventional catalytic cracking feedstock oil are relatively low, while heavy oil catalytic cracking is to mix different proportions of vacuum residue oil into conventional catalytic cracking feedstock oil or directly use full-distillation atmospheric pressure residue oil. Due to changes in the feed oil, the increase in colloid, asphaltenes, heavy metals and carbon residue values, especially the change in group composition, has a great impact on the catalytic cracking process. Therefore, for heavy oil catalytic cracking, we must first solve the impact of high residual carbon value and high heavy metal content on the catalytic cracking process in order to better utilize limited petroleum resources. Table 3-3 and Table 3-4 list the properties of several atmospheric pressure residues and vacuum residues in my country. (2) Indicators for measuring the properties of raw materials The following indicators are usually used to measure the properties of raw oil. 1. Fraction composition Fraction composition can determine the weight of raw materials and the width of the boiling point range. When the chemical composition of the feed oil is similar, the heavier the fraction, the easier it is to crack. ； The lighter the fraction, the less likely it is to crack. Due to the rational utilization of resources, pure wax oil type catalytic cracking has become less and less popular in recent years. 2. Hydrocarbon composition Hydrocarbon composition is usually expressed by the content of alkanes, cycloalkanes, and aromatics. The composition of raw materials varies depending on the source of the raw materials. Paraffin-based raw materials are easy to crack, resulting in low gasoline and coke yields and high gas yields. ； Naphthenic raw materials are the easiest to crack, with high gasoline yield, high octane number and low gas yield. ； Aromatic raw materials are difficult to crack, resulting in low gasoline yield and excessive coking. It is difficult to analyze the hydrocarbon composition of heavy feed oil. It is rarely measured in daily production. This analysis is only done during device calibration. Usually, it is indirectly judged by measuring physical properties such as density, characteristic factor, and aniline point. (1) Density The greater the density, the heavier the raw material. If the fraction composition is the same, the density is high, and the content of naphthenes and aromatics is high ； The density is small and the alkane content is high. (2) Characteristic factor K Characteristic factor is related to density and fraction composition. A high K value of the raw material indicates that it contains many alkanes, and a low K value indicates that it contains many aromatic hydrocarbons (see Table 3-1). The K value of the raw material can be calculated from Engler's distillation data and density. It can also be obtained from density and aniline point lookup plots. (3) Aniline point The aniline point is an indicator of the aromatic hydrocarbon content in the oil. The lower the aniline point, the higher the aromatic hydrocarbon content in the oil. 3. Carbon residue The carbon residue value of raw material oil is one of the main indicators to measure the properties of raw materials. It is related to factors such as the composition of the raw materials, the width of the fraction and the content of gum and asphaltene. If the residual carbon value of the raw material is high, there will be more coke. The residual carbon value in conventional catalytic cracking feedstock is relatively low, generally around 6%. In the catalytic cracking of heavy oil, part of the vacuum residual oil is mixed into the raw material or the full-distillation atmospheric pressure residual oil is directly processed. As the raw material oil becomes heavier, the colloid and asphaltene content increases, and the residual carbon value increases. 4. Among the heavy metals in the metal feed oil, vanadium, nickel, iron, and copper have the greatest impact on the catalyst activity and selectivity. During the catalytic cracking reaction, vanadium electrodes are easily deposited on the catalyst. During regeneration, the vanadium is transferred to the molecular sieve position and reacts with the molecular sieve to generate a eutectic compound with a melting point of 632°C, destroying the crystal structure of the catalyst and permanently deactivating it. Nickel is deposited on the catalyst and transferred to the position of the molecular sieve, but does not destroy the molecular sieve. It only partially neutralizes the acidic center of the catalyst and has little effect on the catalyst activity. Since nickel itself is a dehydrogenation catalyst, the dehydrogenation reaction can be carried out under the temperature and pressure conditions of the catalytic cracking reaction, thereby increasing the hydrogen yield and reducing the liquid. Alkali metal sodium, calcium, etc. in the raw materials also affect the catalytic cracking reaction. The deposition of Na on the catalyst will affect the thermal stability, activity and selectivity of the catalyst. With the development of heavy oil catalytic cracking, people are paying more and more attention to the hazards of Na. Na not only causes acid poisoning of the catalyst, but also generates a low melting point sodium vanadate eutectic with the vanadium oxide deposited on the catalyst surface, which forms a molten state at the high temperature of catalyst regeneration, damaging the molecular sieve lattice and reducing activity. This degree of toxicity becomes more severe as the temperature increases (see Table 3-5). Therefore, for heavy oil catalytic cracking, the Na content of the raw material must be strictly controlled, generally controlled below 5 mg/kg. 5. Sulfur and nitrogen content Nitrogen-containing compounds in the raw materials, especially when the content of basic nitrogen compounds is high, will cause catalyst poisoning and decrease its activity. Studies have shown that when 0.1% (mass) of alkaline nitrogen compounds are added to the cracking raw material, the cracking reaction speed decreases by about 50%. In addition, basic nitrogen compounds are one of the important reasons for the discoloration of product oil and the deterioration of oxidation stability. The sulfur-containing compounds in the raw materials have no significant impact on the catalyst activity. In the test, the raw materials containing 0.35% to 1.6% sulfur were not found to have an impact on the catalytic cracking reaction rate. However, sulfur will increase equipment corrosion, increase the sulfur content of products, and pollute the environment. Therefore, attention should be paid to the sulfur and nitrogen content in raw materials and products during the catalytic cracking production process. If the content is too high, pre-refining treatment is required. (3) Products and Product Characteristics During the catalytic cracking process, when the raw materials, catalysts and reaction conditions used are different, the yields and properties of the products obtained will also be different. But in general, catalytic cracking products have many characteristics compared with thermal cracking. 1. Gas products Under general industrial conditions, the gas yield is about 10 to 20%, and the components included are hydrogen, hydrogen sulfide, and C1 to C4 hydrocarbons. The hydrogen content mainly depends on the degree of contamination of the catalyst by heavy metals. H2S is related to the sulfur content of the raw material. C1 is methane, C2 is ethane and ethylene, and the above substances are called dry gas. A large amount of C3 and C4 (called liquid hydrocarbons or liquefied gases) in the catalytic cracking gas are, among which C3 is propane and propylene, and C4 includes 6 components (n-, iso-butane, n-butene, iso-butene and cis- and trans-2-butene). The characteristics of gas products are as follows: (1) C3 and C4 account for the vast majority of gas products, about 90% (weight), with less C2 and below. There is less C3 than C4 in liquefied gas, and the C4 content in liquid hydrocarbons is about 1.5 to 2.5 times that of C3. (2) There are more olefins than alkanes. The olefins in C3 are about 70%, and the olefins in C4 are about 55%. (3) C4 contains more isobutane, less n-butane, more n-butene, and less isobutylene. The above characteristics make catalytic cracking gas a good raw material for the petrochemical industry. The dry gas from catalytic cracking can be used as fuel and as a raw material for ammonia synthesis. Since it contains some ethylene, ethylene oxide can be produced through hypochlorous acidification to produce ethylene glycol, ethylenediamine and other chemical products. Liquid hydrocarbons, especially olefins, can produce three major synthetic products such as various organic solvents, synthetic rubber, synthetic fibers, and synthetic resins, as well as various high-octane gasoline components such as superimposed oil, alkylate oil, and methyl tert-butyl ether. 2. Liquid products (1) The yield of catalytically cracked gasoline is 40 to 60% (mass). Because there are more olefins, isoparaffins and aromatics, the octane number is higher, generally around 80 (MON). Because it contains less alpha olefins among the olefins and basically does not contain dienes, its stability is also relatively good. It contains more low-molecular hydrocarbons, has lower temperatures at its 10% point and 50% point, and has good performance. (2) The yield of diesel is 20 to 40% (mass). Because it contains more aromatic hydrocarbons, about 40 to 50%, the cetane number is much lower than that of straight-run diesel, only about 35. It often needs to be blended with straight-run diesel before it can be used as diesel engine fuel. (3) Residual oil contains a small amount of catalyst fine powder and is generally not used as a product. It can be returned to the riser reactor for refining. If the catalyst is removed through clarification, some (3-5%) clarified oil can also be produced. Because it contains a large amount of aromatic hydrocarbons, it is a good raw material for the production of heavy aromatic hydrocarbons and carbon black. 3. Coke from coke catalytic cracking is deposited on the catalyst and cannot be used as a product. The coke yield of conventional catalytic cracking is about 5 to 7%. When residual oil is used as raw material, it can be as high as 10% or more, depending on the quality of the raw material. From the above product distribution and product quality, it can be seen that catalytic cracking has its unique advantages, which are incomparable with general thermal destruction processing.

Newcomer registration, learning* Yes, thank you for sharing..

It mainly depends on the carbon residue and density of the raw materials.