- 2 converted to sulfuric acid for manufacturing purposes or to ammonium sulfate
for sale as fertilizer.
Control of smoke and particulate matter is also receiving close attention by the industry. To avoid smoking stacks, many installations include
smoke indicators or recorders, oxygen analyzers, and other instruments to
enable close control of combustion. Where meteorological conditions indicate,
stack heights have been extended to assure complete dissipation of stack
effluents. Afterburners have been installed in many cases to eliminate coke
fines, hydrocarbons, and carbon monoxide in the stack gases. Catalyst collection devices such as cyclones and precipitators are in use to reduce the
emission of dust to the atmosphere.
The researches of Haagen-iEmit and others have shown that under certain
conditions, hydrocarbons and oxides of nitrogen can participate in the photochemical reactions that lead to the formation of "smog." Therefore in Los
Angeles, where ventilation is poor, additional emphasis has been placed on
the recovery and control of hydrocarbons. Before control can be effective,
the principal sources of hydrocarbon loss must be recognized and evaluated.
Individual companies, working cooperatively through industry trade associations and with control agencies, the USPHS, and others, have conducted
extensive surveys of refinery hydrocarbon losses. Steady progress has been
made in reducing evaporation losses from storage tanks, pumps, wholesale
distributing facilities, and water/oil separator operations, to name but a
few. For example, the installation of vapor collection systems and floating
roofs on gasoline tanks has cut evaporation losses some 70$ in the past few
years. In instances where hydrocarbons are unavoidably released from a
process unit, smokeless flares have been installed to incinerate the gas
completely so that only carbon dioxide and water vapor escape to the atmosphere. Again referring to Los Angeles County, since it is the most completely documented area, the total daily loss of hydrocarbons from refining
operations is less than the evaporation loss from carburetors and gasoline
tanks of automobiles operating on the streets on a hot summer day.
Odor abatement is another of the important phases of air pollution
control. Throughout the petroleum refining industry the philosophy is being
adopted that refineries don't have to smell bad. Incineration at high temperature to destroy such odor-producing materials as hydrogen sulfide or
mercaptans and the use of air oxidation to convert sulfur compounds to water
soluble salts are examples of odor control. Spent caustic soda solutions
containing phenols and sulfur compounds are potential odor sources in the
industry. Careful control of these waste solutions going into sewers,
chemical treatment of the wastes, and, in some cases, sale of the waste
materials to outside chemical companies for recovery of by-products, has
done much to eliminate the odor problem. In general, these are not profitable operations but again reflect the efforts of the industry to be good
citizens in the communities in which it operates.'
Ten years ago very little was known about the chemistry of the atmosphere and the mechanism of reactions leading to air pollution. Following
World War II and the growth in population and industry on the West Coast, the
increase in "smog" in Los Angeles County prompted regulations governing the
emission of atmospheric pollutants. None of these proved effective in eliminating the nuisance. About l^kj the Western Oil and Gas Association decided
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Source: http://industrydocuments.library.ucsf.edu/tobacco/docs/nycm0047