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What is the first main step in the production process?
What is the first main step in the production process?
Silanol groups are considered acidic in nature.
Silanol groups are considered acidic in nature.
False
What type of acid sites are formed during dehydration at high temperatures?
What type of acid sites are formed during dehydration at high temperatures?
Lewis acidic sites
Zeolites are synthesized by mixing Na2SiO3 and NaAlO2 in a specific ____ range.
Zeolites are synthesized by mixing Na2SiO3 and NaAlO2 in a specific ____ range.
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Match the properties of zeolite catalysts with their descriptions:
Match the properties of zeolite catalysts with their descriptions:
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What happens to zeolite catalysts in the presence of steam during the stripping and regeneration step?
What happens to zeolite catalysts in the presence of steam during the stripping and regeneration step?
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Zeolite catalysts have low reaction rates due to the high concentration of reactants within pores.
Zeolite catalysts have low reaction rates due to the high concentration of reactants within pores.
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What do quaternary ammonium salts do in zeolite cavities?
What do quaternary ammonium salts do in zeolite cavities?
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Silica hydrogel contains silanol groups at the ____.
Silica hydrogel contains silanol groups at the ____.
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Which product is produced at the highest rate during fluid coking?
Which product is produced at the highest rate during fluid coking?
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NOVEL COKE is produced by cracking inside the reactor.
NOVEL COKE is produced by cracking inside the reactor.
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What substance undergoes partial combustion in the burner?
What substance undergoes partial combustion in the burner?
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What is the primary purpose of hydrotreating?
What is the primary purpose of hydrotreating?
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The addition of a gasifier in flexicoking makes the process more _____ by converting about 90% of the feed into liquids and gas.
The addition of a gasifier in flexicoking makes the process more _____ by converting about 90% of the feed into liquids and gas.
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Organometallic compounds do not affect catalyst activity.
Organometallic compounds do not affect catalyst activity.
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What is the pressure range typically used during hydrotreating?
What is the pressure range typically used during hydrotreating?
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Match the following products with their respective yields in delayed coking:
Match the following products with their respective yields in delayed coking:
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The process of removing hydrogen sulfide by washing is known as ______.
The process of removing hydrogen sulfide by washing is known as ______.
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What is the purpose of the cyclone in the coking process?
What is the purpose of the cyclone in the coking process?
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Match the catalyst type to its primary reaction:
Match the catalyst type to its primary reaction:
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Which of the following is NOT a compound targeted for removal during hydrotreating?
Which of the following is NOT a compound targeted for removal during hydrotreating?
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The presence of sulfur decreases SO2 emissions during catalyst regeneration.
The presence of sulfur decreases SO2 emissions during catalyst regeneration.
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What common issue can nitrogen cause during the catalyst process?
What common issue can nitrogen cause during the catalyst process?
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V is known to cause ______ which negatively affects catalyst performance.
V is known to cause ______ which negatively affects catalyst performance.
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What is one of the functions of the Claus process?
What is one of the functions of the Claus process?
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What is the primary purpose of hydrotreating?
What is the primary purpose of hydrotreating?
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Hydrocracking typically results in a lower conversion rate compared to hydrotreating.
Hydrocracking typically results in a lower conversion rate compared to hydrotreating.
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What catalyst is used in hydrotreating processes and is sensitive to sulfur?
What catalyst is used in hydrotreating processes and is sensitive to sulfur?
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The process by which heavy crude oils require additional treatments is known as __________.
The process by which heavy crude oils require additional treatments is known as __________.
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Match the following processes with their main characteristics:
Match the following processes with their main characteristics:
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Which process is more appropriate for producing diesel rather than gasoline?
Which process is more appropriate for producing diesel rather than gasoline?
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All petroleum products are considered high-value products.
All petroleum products are considered high-value products.
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What are the characteristics of the residue used in petroleum processing?
What are the characteristics of the residue used in petroleum processing?
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In the petrochemical industry, processes transform low-value raw materials into high-value products through __________.
In the petrochemical industry, processes transform low-value raw materials into high-value products through __________.
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What is a common feature of both hydrotreating and hydrocracking?
What is a common feature of both hydrotreating and hydrocracking?
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What is used to cut petroleum coke from the drum?
What is used to cut petroleum coke from the drum?
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The vapours exit the column from the bottom and return to the fractionator.
The vapours exit the column from the bottom and return to the fractionator.
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What is the temperature range of the scorching coke in the fluidized bed reactor?
What is the temperature range of the scorching coke in the fluidized bed reactor?
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The _____ is recovered and sent to other refinery units for gasoline production.
The _____ is recovered and sent to other refinery units for gasoline production.
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Match the types of gas oil with their processing purpose:
Match the types of gas oil with their processing purpose:
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What happens to the water separated from coke in the coke pit?
What happens to the water separated from coke in the coke pit?
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A fluidized bed reactor uses a coke furnace-burner unit to maintain motion.
A fluidized bed reactor uses a coke furnace-burner unit to maintain motion.
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What is the primary use of petroleum coke?
What is the primary use of petroleum coke?
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The OFFLINE DRUM is ______, ______, and ______ before the drum is opened to the atmosphere.
The OFFLINE DRUM is ______, ______, and ______ before the drum is opened to the atmosphere.
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What process occurs when the feed meets the scorching coke?
What process occurs when the feed meets the scorching coke?
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Study Notes
Production Process
- The production process involves three main steps: preparation of porous silica gel, addition of aluminum salt, and dehydration at temperatures exceeding 400 °C.
- The preparation stage creates spherical particles of silica hydrogel with silanol groups on the surface.
- Aluminum salts, specifically Al(OH)3·3H2O, react with silanol groups to impart a negative charge on Al3+, balanced by hydrated cations on the silica surface.
- Dehydration converts Brønsted acidic sites to Lewis acidic sites, enhancing catalytic activity.
- Catalysts derived from this process exhibit low thermal stability and are prone to sintering, especially in steam environments during stripping and regeneration.
Zeolite Catalysts
- Zeolites are natural crystalline catalysts made of sodium alumino-silicates with a porous 3D structure.
- Synthesized by mixing Na2SiO3 and NaAlO2 under specific pH conditions, zeolite crystallization is promoted through heating of the precipitate.
- The size of zeolite cavities can be altered by varying the R group of quaternary ammonium salts included during the synthesis.
- Zeolite catalysts show high selectivity for C5-C10 gasolines and are more active in hydrogen transfer than in hydrocarbon chain cleavage.
- Hydrocarbon cleavage halts at higher molecular weights due to the transformation of hydride ions to carbocations and subsequent olefin hydrogenation.
- Issues with zeolite catalysts include coke formation and potential reversible catalyst inhibition.
Effects of Compounds on Catalysts
- Sulfur increases SO2 emissions during catalyst regeneration, which can be managed through amine washing or the Claus process.
- Nitrogen can generate ammonia, which neutralizes acidic catalyst sites, while oxygen and arsenic can poison Pt catalysts.
- Organometallic compounds convert to heavy metals that can deactivate catalysts, with vanadium specifically causing sintering.
- Sodium and potassium irreversibly neutralize zeolites' acidic sites.
Hydrotreating
- A high-pressure hydrotreating process (5-20 atm) using Co-Mo, Ni-Mo, or Ni-W catalysts is effective for removing sulfur and other heteroatoms before cracking processes.
- This method helps desulfurize gasoils for diesel fuels and fuel oil, minimizing catalyst deactivation during catalytic cracking.
- Hydrotreating serves to reduce coke formation from olefins and ammonia while also removing oxygen, nitrogen, and arsenic to protect Pt catalysts.
Hydrocracking
- Hydrocracking involves severe hydroprocessing to remove heteroatoms and saturate carbon-carbon bonds.
- It results in higher yields of fuel products compared to mild hydrotreating.
- The conversion rate in hydrocracking is notably higher than in mild processes, making products more suitable for diesel rather than gasoline.
Petroleum Products
- The petrochemical industry transforms low-value raw materials into high-value products, often with a higher H/C ratio.
- Residue conversion processes address the treatment of heavy crude oils, recovering valuable products and reducing waste.
- Heavy residue is characterized as high molecular weight, carbon-rich, and low-value, leading to the recovery of fuel gas and LPG and the production of petroleum coke, which can be used as fuel in power plants.
Fluidized Bed Coking
- The fluidized bed coking process integrates a coke reactor with a furnace-burner unit, using steam to maintain coke motion and facilitate cracking at high temperatures (500-550 °C).
- The process generates various product yields, with more gasoil and less gasoline compared to delayed coking.
- A portion of produced coke is collected while combustion gases are removed for carbonaceous particle separation.
Flexicoking
- Flexicoking includes a gasifier to enhance flexibility, converting around 90% of feed into liquids and gases and allowing excess coke to be gasified for energy or chemical production.
Asphaltenes Extraction
- Asphaltenes, the heaviest petroleum components, contain impurities and are solid at room temperature.
- Removing asphaltenes increases gasoil yield during cracking processes and allows for their use as fuels in cement production and asphalt manufacturing.
- The deasphalting process involves solvent recovery of non-asphaltene materials from both atmospheric and vacuum residues.
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Description
Explore the three main steps involved in the production process of porous silica gel. This quiz covers the preparation, addition of aluminum salt, and dehydration processes that lead to the formation of silica hydrogel particles with silanol groups. Test your knowledge on this essential chemical engineering topic.
