Module 4-6 Unit 3 Flashcards
Fractionating towers
where petroleum is heated and sorted based on density and boiling points
Fractionating tower process
4 steps
- petrueum is added
- petroleum vaporizes
- the vapor rises further away from the heat source and the tempurature decreases
- when a hydrocarbon component reaches its boiling point (height) in the tower it will condense and be collected, while still allowing other vapor to continue to rise
Large hydrocarbons traits in a Fractionating Tower
3
- higher boiling points
- higher densities
- sorted at the bottom of the tower (by the heating element)
Small hydrocarbons traits in a Fractionating Tower
- lower boiling point
- low density
- sorted at the top of the tower (away from the heating element)
Cracking
Heating of any hydrocarbon under pressure to break C-C bonds (in the absence of air)
Steam Cracking
3 points
- steam at >800’C
- Pressure > atmospheric preassure
- produces shorter alkenes and aromatic hydrocarbons
Catalytic Cracking
3 points
- powdered catylists heated at 600’C
- Low pressure
- produces diesel oil, gasoline and kerosene
Hydrocracking
3 points
- form of catalytic cracking
- hydrogen is added
- produces low-grade gasoline and heating oils
Reforming
Heat, high pressure and catalysts convert straight-chain alkenes into branched alkanes, cycilic alkanes and aromatics
Reformed alkanes and aromatics purpose
- upgrade gasoline
- form plastics and foams
- produces H2 gas (can be used for hydrocracking)
Alkylation
Short chain alkenes are chemically joint under controlled heat and preassure with an acid catalyst
Used to upgrade gasoline
Vacuum Distilation
Risidual unprocessed crude oil at the bottom of the fractionating tower is heated to 800’C it cracks into a number of products
Vacuum Distilation Products
Heavy oil, gasoline, cycloalkanes, waxes and coke (solid carbon residue)
Solvent extraction
removes impurites from heavy oil fractions, and can be performed on large or small scales
Solvent extraction steps
4 steps
- sample is placed in a speratory funnel
- solvent is added (should be oposite polarity of sample: nonpolar or polar depending)
- the more dense layer that forms at the bottom is extracted
- steps 2+3 can be repeated with a “wash” of solvent to isolate all entities from the sample
Precipitation separation
separates entities based on their solubility by using a solution to form a precipitate
Complete combustion reaction
reacton of hydrocarbons with Oxygen to produce oxygen, wator vapor, and energy
Hydrocarbon + O2 (g) –> CO2 (g) + H2O (g) + energy
Addition reaction
A reaction where atoms are added to a double or tripple bond
double/triple bond + small reactant = addition reaction
Elimination reaction
a reaction where atoms are removed from a molecule to form double bonds between two carbons
One reactant (loses 2 atoms) –> Alkene + excess product
Alcohol in Elimination reactions
Only produces alkenes in the presence of a Strong Acid (acts as a catalyst) and produces a small stable chemical like water
Alkyl Halides in elimination reactions
Only produces alkenes if they are heated in the presence of a strong base (Ex: NaOCH2CH3)
Isomers in elimination reactions
4 points
- Hydrogens like to be with hydrogens
- Hydrogen is most likely to be removed from the carbon atom with the most carbon bonds
- It can be removed from somewhere else, resulting in two products (isomers)
- “Major product” is the most likely one
Substitution reaction
A reaction where a hydrogen atom or a functional gorup is switched with another
Two compounds react to create two different compounds
Alcohol in a substitution reaction
If reacted with an acid that has a halogen, the halogen switches with the hydroxyl group and makes an alkyl halide
