PTAC Questions and Answers Already Passed

PTAC Questions and Answers Already Passed Jet fuel is hydrotreated naphtha False Ethylene plants are also called olefins plants True To increase cetane number in diesel fuel refiners desire Low aromatics, high paraffins Which olefin plant compressor has the highest volume Cracked gas compressor How many isomers of xylene are there 3 Why are olefins cooled to low temperatures To liquify gases There are 7 grades of fuel False The residence time in an ethane/propane cracker is 1 second, a relatively short period False What are the 3 aromatic products Benzene, Toluene, and Xylene (BTX) In one pass through the cracking furnace about _______ of the ethane and propane are cracked 60-70% In diesel fuel, the measure of self-ignability is Cetane number How many olefins plant compressors are there 3 Cryogenics is the science of The super cold How does toluene differ from benzene One methyl branch What is the difference between gas engine and diesel Diesel has no spark plugs What is the smallest unit that defines chemical elements Atom When atoms are attached to each other they are called Bonds Double bonds are stronger than single bonds False A straight chain hydrocarbon with a single bond is a Paraffins A ringed hydrocarbon with a single bond is a Naphthene A ringed hydrocarbon with a resonating double bond is called Aromatics A straight chain double bonded hydrocarbon is a Olefins A compound with the same number of carbons but different configuration is isomer Isomers have different properties True Olefins are not naturally occuring hydrocarbons True What are the 3 aromatics referred to as BTX Benzene, Toluene, Xylene Methane is further processed in other units True The column that splits the C4's from the fat oil is called Debutanizer The sponge absorber removes lean oil from the ethane and lighter stream False The naphtha range liquid introduced into the top of the rectified absorbs in Lean Oil The naphtha coming out of the rectified absorber in the gas plant that has pr.. Fat Oil An underground natural storage space is called Caverns or Jugs Propylene and Butylene are reacted with what to form an isoparaffin called alkylate Isobutane The catalyst for the alkylation unit is Sulfuric and hydrofluoric acid The caustic wash neutralizes any acid that may remain in the hydrocarbon stream True The reaction time for the alkylation process is relatively short False The debutanizer in the alky plant removes the propane from the alkylate False Alkylation starts with small molecules and ends with larger ones True Thermal cracking and visbreaking is cracking residue to recover lighter products True The only thing that coke can be used for is furnace fire False Delayed coking has one drum being cleaned of coke while the other is letting the coke form True Decoking of coke drums uses High pressure water to cut it In a gasoline engine, compression heats the gas to the point it auto-ignites False To increase octane numbers, refiners desire in their gasoline blends High aromatics, low paraffins Octane number is a measure of whether a gasoline will knock in an engine True The different types of coke are Green, Needle, Calcinable, and Sponge The power stroke on a gasoline engine occurs when The spark plug ignites the gasoline/air mixture What is the formula used for the posted octane number on gasoline pumps Ron+Mon/2 Vapor lock occurs when there is not enough vapor in the system False The sponge absorber removes lean oil from the ethane and lighter stream True When natural gas is turned into LNG it shrinks how much 600x What is LNG Liquified natural gas What are the two sections of the gas plant called Sats and cracked To increase cetane number, desire is Low aromatics, high paraffins