Cyanide Sources in Petroleum Refineries
B. VAIL PRATHER, Staff Specialist
ROBERT BERKEMEYER, Laboratory Manager
Williams Brothers Waste Control, Inc.
Resource Sciences Park
Tulsa, Oklahoma 74136
INTRODUCTION
It has been known for a number of years that some petroleum refinery wastewater
effluents contain traces of cyanides. The nature or configuration of cyanide contained in the
water has not been formally reported, but is usually assumed to be organic or possibly
metallic complexes, subject to decomposition in acidic environment into hydrocyanic acid.
Recent intensified interest in cyanide content of wastewater effluents from all sources
and more particularly petroleum refinery effluent waters prompted Williams Brothers
Waste Control, Inc. to embark on a cyanide research program under contract with an oil
refining corporation.
The customary point of initiation in any research project is a literature search. We
followed this routine, and found there is considerable information on the treatment of
cyanide wastes from metal finishing and plating which contain concentrations of 50 to 300
mg/1 of cyanides. Information on cyanides in petroleum refinery wastewaters, however, is
scant and incomplete, with very little data, leaving much to the imagination.
In order to define the cyanide problem in the refinery, it was logical to locate the
sources of cyanides within the refining process. Accordingly, a plant survey was initiated to
determine those sources as the initial plant action of the research project.
Although there is no published data on cyanide production at refinery units, we did
have private data from one refinery which illustrate the concentrations that exist at various
points in the refinery. Review of this data is shown in Table I.
Although Table I lists concentrations, it does not list water volumes; therefore, it is
impossible to calculate pounds per day of cyanide produced. However, the data suggest that
cyanides are present in the crude, since analyses of crude tank bottoms waters report them
in small concentrations.
No information was given regarding the source of the water which was used in the
desalting process. If the source water was free of cyanide, then the high content shown in the
desalter effluent might be due to washing of the cyanides from the crude, or the electric
desalting process might be forming cyanide.
Atmospheric crude unit fractionator overhead separator waters varied considerably in
cyanide concentration. Again it should be noted that water volumes were not listed.
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