What is the Difference Between Catalytic Cracking and Hydrocracking?
🆚 Go to Comparative Table 🆚Catalytic cracking and hydrocracking are two different processes used in petroleum refineries to convert large hydrocarbon molecules into smaller, more useful ones. The main differences between these two processes are:
- Carbon Rejection vs. Hydrogen Addition: Catalytic cracking involves carbon rejection, whereas hydrocracking involves a hydrogen addition process.
- Endothermic vs. Exothermic: Catalytic cracking is an endothermic process, while hydrocracking is an exothermic process. Catalytic cracking requires heat for the regeneration of catalysts, whereas hydrocracking generates heat during the process.
- Catalysts: Catalytic cracking uses solid acid catalysts, usually silica-alumina and zeolites, to promote the formation of carbocations and break C-C bonds. Hydrocracking, on the other hand, uses a bifunctional catalyst that combines hydrogenation and cracking.
- Feedstock Range: Hydrocracking can handle a wider range of feedstock compared to catalytic cracking.
- Product Yield: Fluid catalytic cracking produces a high yield of petrol and LPG, while hydrocracking is a major source of jet fuel, diesel fuel, naphtha, and LPG.
Both processes are used in petroleum refineries to optimize the yield of products, but hydrocracking is generally a more costly process.
Comparative Table: Catalytic Cracking vs Hydrocracking
The main differences between catalytic cracking and hydrocracking are their processes, feedstock flexibility, and byproducts. Here is a comparison table of the two processes:
| Feature | Catalytic Cracking | Hydrocracking |
|---|---|---|
| Process | Carbon rejection | Hydrogen addition |
| Type of Reaction | Endothermic | Exothermic |
| Feedstock Flexibility | High | Moderate |
| Byproducts | Low-grade byproducts (e.g., gas, coke) | High yields of valuable distillates without producing low-grade byproducts (e.g., gas, coke) |
| Process Objective | Convert high boiling point, high molecular weight hydrocarbons into gasoline, olefinic gases, and other petroleum products | Convert high boiling constituents into low boiling constituents |
| Catalyst Susceptibility | Not susceptible to poisoning | Susceptible to poisoning |
| Hydrotreating | Not typically accompanied | Typically accompanied |
Catalytic cracking, or fluid catalytic cracking, is the conversion of high boiling point, high molecular weight hydrocarbons into gasoline, olefinic gases, and other petroleum products. It is an endothermic process that involves carbon rejection. On the other hand, hydrocracking is the process of converting high boiling constituents into low boiling constituents. It is an exothermic process that involves a hydrogen addition process.
Catalytic cracking has a higher feedstock flexibility and is less costly than hydrocracking. However, hydrocracking provides high yields of valuable distillates without producing low-grade byproducts, such as gas or coke. Additionally, hydrocracking is typically accompanied by hydrotreating to remove heteroatom species (e.g., S, N, and O), while catalytic cracking is not.
- Hydrocracking vs Hydrotreating
- Hydrogenation vs Hydrogenolysis
- Catalytic vs Non Catalytic Reaction
- Hydrogen Embrittlement vs Stress Corrosion Cracking
- Homogeneous vs Heterogeneous Catalyst
- Catalytic vs Stoichiometric Reagents
- Acid Hydrolysis vs Enzymatic Hydrolysis
- Hydration vs Hydrogenation
- Isomerization vs Hydroisomerization
- Photocatalysis vs Electrocatalysis
- Hydrolysis vs Dehydration Synthesis
- Hydrolysis vs Condensation
- Hydration vs Hydrolysis
- Alternant vs Nonalternant Hydrocarbons
- Calcination vs Pyrolysis
- Steam Distillation vs Hydrodistillation
- Hydrolysis vs Dehydration
- Hydrogenation vs Reduction
- Cocaine vs Crack