What is the Difference Between Catalytic Cracking and Hydrocracking

Thekey difference between catalytic cracking and hydrocrackingis that catalytic cracking involves carbon rejection, whereas hydrocracking involves a hydrogen addition process.

Cracking processes are very important inpetroleumrefineries and help in converting large molecules to small compounds, which in turn increase the octane rating of汽油。催化裂纹或更精确的流体催化裂纹是转化hydrocarbons高沸点和高分子重量为汽油，烯烃气体和其他石油产品。加氢裂缝是将高沸腾成分转化为低沸腾成分的过程。

内容

1.Overview and Key Difference
2.What is Catalytic Cracking
3.什么是加氢裂
4.催化裂化vs Hydrocracking in Tabular Form
5.Summary – Catalytic Cracking vs Hydrocracking

What is Catalytic Cracking?

催化裂纹或更精确的流体催化裂纹是高沸点，高分子量碳氢化合物转化为汽油，烯烃气体和其他石油产品。这是一个用于石油炼油厂的转换过程。有一个高沸点，高分子的原油（石油）经历了催化裂纹。

Originally, the cracking process of petroleum was done using thermal techniques. However, now it is replaced largely by catalytic cracking. This is because the latter yields a greater volume of high octane rating gasoline. Moreover, it produces byproduct gases having more carbon=carbon double bonds, such as olefins. Therefore, catalytic cracking is more economically valuable than the thermal cracking process.

For the fluid catalytic cracking process, the feedstock is heavy gas oil. It is the portion of petroleum having an initial boiling temperature of 340 Celsius degrees or above. Moreover, the molecular weight ranges from 200 to 600 or higher in these fractions.

什么是加氢裂?

加氢裂缝是将高沸腾成分转化为低沸腾成分的过程。That means the reactants of hydrocracking reaction are constituents of petroleum oil having high boiling points, and the products are compounds having low boiling points. Furthermore, this process is important because low boiling products are more valuable hydrocarbons, which include gasoline, kerosene, jet fuel, diesel, etc.

The process of hydrocracking is named as such because the breakdown of large molecules occurs in the presence of hydrogen gas. Generally, hydrocracking is done under severe conditions. It is because the reactants of hydrocracking feedstock are exposed to the reactor temperature for a long time.

We can define this process as a type of catalytic cracking because it also uses a catalyst to speed up the process; a metal catalyst. Typically, this process gives saturated hydrocarbons. However, the type of hydrocarbon given is dependent on the reaction conditions, which include the temperature of the reaction mixture, pressure, and catalytic activity. The products may include ethane, LPG, and isoparaffins.

催化破裂和加氢裂缝有什么区别？

Cracking processes are very important in petroleum refineries and help in converting large molecules into small compounds, which in turn increase the octane rating of gasoline. The key difference between catalytic cracking and hydrocracking is that catalytic cracking involves carbon rejection, whereas hydrocracking involves a hydrogen addition process. Moreover, catalytic cracking is an endothermic process while hydrocracking is an exothermic process.

The below infographic presents the differences between catalytic cracking and hydrocracking in tabular form for side by side comparison。

Summary – Catalytic Cracking vs Hydrocracking

Catalytic cracking, or more precisely, fluid catalytic cracking, is the conversion of high boiling point, high molecular weight hydrocarbons into gasoline, olefinic gases, and other petroleum products. Hydrocracking is the process of converting high boiling constituents into low boiling constituents. The key difference between catalytic cracking and hydrocracking is that catalytic cracking involves carbon rejection, whereas hydrocracking involves a hydrogen addition process.

Reference:

1.“”催化裂化。”概述|ScienceDirect主题。

Image Courtesy:

1.“”Fluid Catalytic Cracker“ 经过Valero Energy Corporation/TX- （公共领域）通过CONSONS WIKIMEDIA
2. “Slovnaft – residual hydrocracking (RHC)“ 经过Mikulova – Own work(CC BY-SA 3.0)via Commons Wikimedia