Hydrocarbons (1) Flashcards
what is organic chemistry?
branch of chemistry that deals with compounds of carbon, excluding oxides and ionic compounds of carbon based ions
what are hydrocarbons
compounds containing carbon atoms bonded to hydrogen atoms
what is refining
technology that includes separating physical and chemical processes for separating complex mixtures into simpler mixtures or near-pure components
refining - natural gas
extraction: natural pressure underground
physical: condensation and distillation
chemical: removal of hydrogen sulfide and carbon dioxide at a gas plant
uses: heating building, source of ethane, propane, and butane
coalbed methane refining
extraction: water removed from underground if necessary
physical: removal and disposal of saline water
chemical: removal of noncombustibles at gas plant
uses: natural gas uses, + production of hydrogen and methanol
crude oil refining
extraction: water or gas injection underground
physical: water, sand, and salt removal, and fractional distillation tower
chemical: hydrocracking and catalytic reforming
uses: gasoline, jet fuel, and asphalt
heavy oil refining
extraction: steam injection underground
physical: separation from water and solids, fractional distillation
chemical: heavy oil hydrocracking and catalytic reforming
uses: gasoline, jet fuel, and asphalt (same as crude)
oil sands refining
extraction: physical mining and in situ steam or hot water injection
physical: hot water extraction and floatation, centrifugation, fractional distillation
chemical: coking, hydrocracking, hydrotreating
uses: synthetic crude used as crude oil
coal refining
extraction: surface and underground mines
physical: sorting crushing and/or grinding
chemical: none, or gasification or alternative delivery
uses: energy for producing electricity
what is fractionation
taking advantage of the differences in boiling points to physically separate the components
what are fractions
product in fractionation process, identified by boiling-point range or # of carbon atoms in molecules
lower boiling points = smaller molecules
what are alkanes
-hydrocarbons whose empirically determined molecular formulas indicate that the carbon-to-carbon bonds are only single bonds
- general formula: CnH2n+2
- example of both homologous series and saturated hydrocarbon
what is a homologous series
sequence of molecules with similar structure and differing only the number of repeating units (e.g. Ch2)
what are saturated hydrocarbons
compounds of carbon and hydrogen containing only carbon-carbon single bonds, with max number of hydrogen atoms bound to each carbon
prefix formula (1-10) for carbon atoms and alkanes
meth - 1
eth - 2
prop -3
but - 4
pent - 5
hex - 6
hept - 7
oct - 8
non - 9
dec - 10
what are structural isomers?
compounds with same molecular formula but different structures
explain difference in physical and chemical properties
as carbon atoms increase, # of isomers increase
what is an alkyl branch?
branch consisting of only carbon and hydrogen atoms
prefix followed by -yl
what are cycloalkanes
when all carbon-carbon bonds in a cyclic hydrocarbon are single bonds
what are alkenes
hydrocarbons with carbon-carbon double bonds
end in -ene
general formula: Cnh2n
cycloalkanes are isomers are alkenes
what is hydrogenation
adding sufficient quantity of hydrogen to convert unsaturated hydrocarbons to saturated ones
what are alkynes
- chemical properties explained by presence of triple carbon bonds
- end in yne
- general formula: CnH2n-2
what are cycloalkenes
- cycle of carbon atoms with at least one double bond
- isomers of alkynes
- general formula: CnH2n-2
what is ethane cracking?
- production of ethene by cracking ethane (large molecules) into smaller hydrocarbons
- ethane separated from gas, piped to plant, and broken down by removal of two hydrogen atoms
what are aliphatic hydrocarbons?
broad class including straight or branched chains or rings of alkanes, alkenes and alkynes, but not aromatics
what are aromatics
benzene, and al other carbon compounds that contain benzene-like structures and properties
contain benzene ring
what is a phenyl group
benzene ring in aromatic, attached as branch on parent chain
what is hydrocracking
combination of catalytic cracking and hydrogenation, often with those of complex aromatic compounds
larger molecule + hydrogen = smaller molecules
what is catalytic cracking
breaks apart larger molecules with the presence of a catalyst, produce less residual material and more desirable fractions
larger molecules = smaller molecules + carbon
what is catalytic reforming?
chemical processes involved in converting molecules in naphtha (gasoline) into aromatic gasoline molecules, have better burning properties
aliphatic molecule = aromatic molecule + hydrogen
