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
Akyl halide in a substutution reaction
If reacted with a hydroxide ion, the hydroxide switches with the halogen and makes an alcohol
can also happen in a strong base
Alkanes in a substitution reaction
Reacts with chlorine or Bromine in the presence of ultraviolet light
Aromatic Hydrocarbons in a substitution reaction
Reacts with chlorine or bromine if there is a catalyst
Esterification Reaction
A reaction where alcohol combines with a carboxylic acid to make an ester and H2O
is an example of a condensaton reaction
Condensation reaction
a reaction where two molecules combine to form a large molecule, and also makes a small molecule (usually water)
Polymer
- very long molecule made by linking monomers together
- can be natural or synthetic
- can consist of different monomers
DNA is a polymer with 4 different monomers
Plastics
Polymers that can be heated and shaped into different forms
Naming a polymer
Use the prefix “poly-“ before the name of the monomer
Ester linkage
3 traits
- happens in condensation polymerization
- bonds a polyester together
- produces water
Addition polymerization
2 traits
- Alkene monomers joined together with addition reactions
- use broken double bonds to join monomers together
Condensation polymerization
2 traits
- Monomers combined with multiple condensation reactions
- each monomer must have two functional groups (one at each end)
Polyester
a carboxyl group (-COOH) and an alcohol group (-OH) react to make an polymer ester group (COOC)
Amide linkage
3 traits
- happens in condensation polymerization
- Bonds polyamide/nylon together
- produces water
Polyamide
an amino group (NH2) and a carboxyl group (COOH) makes an amide group (CONC)
Environmental considerations of producing PVC
3 points
- dioxins are released during production, which are highly toxic
- produces gas emmissions and water contamination
- many synthetic polymers to not degrade in the environment
Cellulose
a polymer of glucose that makes up fibre in our diet
We cannot digest it
Starch
a polymer of glucose that has lots of branching
Glycogen
a polymer of glucose that is highly branched (more than starch). Animals use it as emergency glucose storage
Protein
a polymer made of amino acid monomers linked together with amide linkages
20 different amino acids
DNA
A polymer made from nucleotides that each contain a sugar, a phosphate and a nitorgenous base (A,C,G,T)
