PETROLEUM
organisms exposed to oil.
Incomplete combustion of petroleum or petrol results in production of toxic byproducts.
Too little oxygen results in carbon monoxide. Due to the high temperatures and high
pressures involved, exhaust gases from petrol combustion in car engines usually include
nitrogen oxides which are responsible for creation of photochemical smog.
Formation
Structure of a vanadium porphyrin compound (left) extracted from petroleum by Alfred E.
Treibs, father of organic geochemistry. Treibs noted the close structural similarity of this
molecule and chlorophyll a (right).
Petroleum is a fossil fuel derived from ancient fossilized organic materials, such as
zooplankton and algae. Vast quantities of these remains settled to sea or lake bottoms,
mixing with sediments and being buried under anoxic conditions. As further layers
settled to the sea or lake bed, intense heat and pressure built up in the lower regions.
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