Podcast
Questions and Answers
What is the primary function of the riser in the catalytic cracking process?
What is the primary function of the riser in the catalytic cracking process?
The catalytic cracking process operates at temperatures below 500 °C.
The catalytic cracking process operates at temperatures below 500 °C.
False
Which impurities are commonly found in residues?
Which impurities are commonly found in residues?
What is used in the catalyst stripper to improve the removal of products from catalyst particles?
What is used in the catalyst stripper to improve the removal of products from catalyst particles?
Signup and view all the answers
The Conradson carbon index for catalytic cracking residues should be higher than 15%.
The Conradson carbon index for catalytic cracking residues should be higher than 15%.
Signup and view all the answers
What types of processes are considered hydrogenation processes?
What types of processes are considered hydrogenation processes?
Signup and view all the answers
Coke is removed from the catalytic surface by burning it in the _____________ at temperatures around 680°C - 720°C.
Coke is removed from the catalytic surface by burning it in the _____________ at temperatures around 680°C - 720°C.
Signup and view all the answers
Match the following components with their respective roles in the catalytic cracking process:
Match the following components with their respective roles in the catalytic cracking process:
Signup and view all the answers
Coke deposition on catalysts during catalytic cracking is more _____ than in normal gasoil catalytic cracking.
Coke deposition on catalysts during catalytic cracking is more _____ than in normal gasoil catalytic cracking.
Signup and view all the answers
Match the following impurities with their effects on yield:
Match the following impurities with their effects on yield:
Signup and view all the answers
What technological innovation helps to minimize non-selective thermal cracking?
What technological innovation helps to minimize non-selective thermal cracking?
Signup and view all the answers
What is the purpose of cooling systems within the regenerator unit of modern reactors?
What is the purpose of cooling systems within the regenerator unit of modern reactors?
Signup and view all the answers
Air combustion in the regenerator heats catalyst particles to necessary temperatures.
Air combustion in the regenerator heats catalyst particles to necessary temperatures.
Signup and view all the answers
Residue catalytic cracking requires special catalysts due to low metal content in feed.
Residue catalytic cracking requires special catalysts due to low metal content in feed.
Signup and view all the answers
What is the typical diameter range of the riser used in the catalytic cracking process?
What is the typical diameter range of the riser used in the catalytic cracking process?
Signup and view all the answers
The temperature range for burning coke in the regenerator is ___________ °C.
The temperature range for burning coke in the regenerator is ___________ °C.
Signup and view all the answers
Give an example of a thermal (T) process in the context of carbon removal.
Give an example of a thermal (T) process in the context of carbon removal.
Signup and view all the answers
Which of the following products is NOT included in the lighter fractions separated in the fractionator?
Which of the following products is NOT included in the lighter fractions separated in the fractionator?
Signup and view all the answers
Catalytic cracking is suitable for residues with a Conradson carbon index lower than _____%.
Catalytic cracking is suitable for residues with a Conradson carbon index lower than _____%.
Signup and view all the answers
What main advantage does the high severity down flow FCC process have over traditional methods?
What main advantage does the high severity down flow FCC process have over traditional methods?
Signup and view all the answers
The hydrocracking process operates under milder conditions without the formation of coke.
The hydrocracking process operates under milder conditions without the formation of coke.
Signup and view all the answers
Name one concern associated with excessive catalyst loading.
Name one concern associated with excessive catalyst loading.
Signup and view all the answers
The addition of ________ in the hydrocracking process leads to a more flexible process.
The addition of ________ in the hydrocracking process leads to a more flexible process.
Signup and view all the answers
Match the following terms related to hydrocracking with their descriptions:
Match the following terms related to hydrocracking with their descriptions:
Signup and view all the answers
What is a consequence of high catalyst circulation in the down flow FCC process?
What is a consequence of high catalyst circulation in the down flow FCC process?
Signup and view all the answers
Single stage hydrocracking typically achieves high conversion rates above 60%.
Single stage hydrocracking typically achieves high conversion rates above 60%.
Signup and view all the answers
What type of catalysts are commonly used in the hydrocracking process?
What type of catalysts are commonly used in the hydrocracking process?
Signup and view all the answers
The high severity down flow FCC process requires higher temperatures around ________ degrees Celsius.
The high severity down flow FCC process requires higher temperatures around ________ degrees Celsius.
Signup and view all the answers
Which of the following is NOT a concern identified in the high severity down flow FCC process?
Which of the following is NOT a concern identified in the high severity down flow FCC process?
Signup and view all the answers
Which compound is NOT produced through steam cracking?
Which compound is NOT produced through steam cracking?
Signup and view all the answers
The choice of feedstock for steam cracking does not have to consider market demand.
The choice of feedstock for steam cracking does not have to consider market demand.
Signup and view all the answers
What type of bonds are broken during the thermal cracking process?
What type of bonds are broken during the thermal cracking process?
Signup and view all the answers
Steam cracking operates at high temperatures around _______ °C.
Steam cracking operates at high temperatures around _______ °C.
Signup and view all the answers
Match the following products with their respective annual production quantities:
Match the following products with their respective annual production quantities:
Signup and view all the answers
What is a significant advantage of using DAO STRIPPER and asphaltenes stripper for solvent recovery?
What is a significant advantage of using DAO STRIPPER and asphaltenes stripper for solvent recovery?
Signup and view all the answers
What is the main goal of the deasphalting process in lube oil manufacture?
What is the main goal of the deasphalting process in lube oil manufacture?
Signup and view all the answers
The yield of deasphalting processes typically ranges from 75% to 85%.
The yield of deasphalting processes typically ranges from 75% to 85%.
Signup and view all the answers
What are light paraffins used for in the deasphalting process?
What are light paraffins used for in the deasphalting process?
Signup and view all the answers
The solvent used for supercritical extraction is often _____ for optimal results.
The solvent used for supercritical extraction is often _____ for optimal results.
Signup and view all the answers
Match the following terms with their descriptions:
Match the following terms with their descriptions:
Signup and view all the answers
Which of the following is a characteristic of supercritical extraction processes?
Which of the following is a characteristic of supercritical extraction processes?
Signup and view all the answers
Increasing the extraction pressure enhances the solubility of asphaltenes.
Increasing the extraction pressure enhances the solubility of asphaltenes.
Signup and view all the answers
What happens to the metal content during the deasphalting process yield increase?
What happens to the metal content during the deasphalting process yield increase?
Signup and view all the answers
The process used to figure out the best compromise between DAO yield and _____ is important.
The process used to figure out the best compromise between DAO yield and _____ is important.
Signup and view all the answers
What is one of the main benefits of using supercritical fluids in extraction?
What is one of the main benefits of using supercritical fluids in extraction?
Signup and view all the answers
Study Notes
Components and Impurities in Residue
- Residue consists of saturates, aromatics, resins, and asphaltenes.
- Common impurities include sulfur (S), nitrogen (N), and heavy metals.
- "Residue" encompasses distillation residues, heavy oils, bitumen, and tar sands.
Hydrocracking and Hydrogenation Processes
- Hydrocracking is a catalytic cracking process involving hydrogen, allowing use of less valuable feeds like crude oil.
- It requires higher operational and investment costs due to hydrogen needs.
- Milder cracking conditions prevent coke formation, leading to olefin saturation and effective desulfurization.
Catalytic Cracking of Residue
- Improvements in gasoil fluid catalytic cracking (FCC) enable higher gasoline yield.
- Special catalysts are necessary due to the presence of metals in the feed.
- Nickel (Ni) and vanadium (V) levels must be monitored; exceeding 10-30 ppm may necessitate hydrogen treatment.
- Coke formation from Ni reduces liquid yield and from V lowers conversion and yield.
Catalyst Regeneration and Efficiency
- Catalyst coking is more common in residue catalytic cracking compared to gasoil.
- Modern reactors utilize cooling systems and regeneration units to manage excess heat.
- A Conradson Carbon Index lower than 15% makes residue suitable for catalytic cracking.
Riser and Reactor Design
- The preheated feed enters a riser (200 t/hour) that facilitates catalytic cracking within 2-4 seconds at temperatures over 500°C.
- Catalyst particles combust in the regenerator at 680°C - 720°C, with air enhancing temperature.
- The catalyst stripper uses steam to aid product removal from catalyst surfaces, assisted by cyclones.
Product Separation
- Products from catalytic cracking are separated in a fractionator, sorting lighter fractions (C1-C2, gasoline, propane, butane) from heavier oils and slurries.
- Non-selective thermal cracking can occur based on temperature and residence time despite plant designs minimizing this effect.
Advanced Catalytic Cracking Techniques
- Millisecond Catalytic Cracking (MSCC) reactor design mitigates non-selective post-riser cracking and enhances gasoline selectivity.
- High Severity Down Flow FCC combats back-mixing by utilizing down flow to improve contact efficiency with catalysts.
- Understand concerns with excessive catalyst loading, circulation, and fines generation that could affect efficiency and emissions.
Deasphalting Processes
- The single-stage process for hydrocracking leads to low conversion rates but aims for asphaltenes removal and increased gasoil yields.
- The multistage deasphalting unit leverages different solubility in solvents, primarily using light paraffins, yielding deasphalted oil (DAO).
Residuum Oil Supercritical Extraction (ROSE)
- ROSE process utilizes supercritical solvents, like CO2, yielding high asphaltene extraction rates with lower costs.
- Supercritical solvents enhance extraction and phase separation rates significantly compared to standard methods.
- DAO separation generates low MW paraffins while heavier fractions remain in the asphaltenic product.
Steam Cracking Overview
- Steam cracking is pivotal in producing ethylene (140 million t/a), propylene (70 million t/a), and C4 olefins.
- Feedstock choices include naphtha, natural gas, and ethane, dictated by market demand.
- This thermal cracking process breaks high MW molecules at temperatures around 900°C, facilitating radical mechanisms.
Steam Cracking Radical Mechanism
- High temperatures induce homolytic bond breaking in large molecules, leading to β-cleavage.
- This process generates ethylene and propylene through radical transformations, capitalizing on the energy difference between primary and secondary radicals.
- Increased molecular entropy drives the reaction, necessitating steam addition to lower hydrocarbon pressures.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
This quiz covers the key components and impurities found in petroleum residues, including saturates and aromatics. It also explores hydrocracking and catalytic cracking processes used to refine crude oil more efficiently. Test your understanding of the effects of impurities on refining and the technologies involved.