Appeal 2007-4234
Application 10/929,891
varies with the type of crude and conditions under which it has been
transported (Specification at 5:15 through 6:2).
[5] Numerous pumping lines are said to be clogged daily or monthly due
to wax precipitating out of the crude oil (Specification at 6:11-12).
[6] Additionally, one of the main sites of corrosion in pipelines and
storage tanks is said to be areas of paraffin wax buildup
(Specification at 7:4-5).
[7] The specification describes chemical dispersants which preferably act
as (i) wax liquifiers, converting slop oil waxes from crystalline to
amorphous forms which are readily dispersible in crude oil; (ii)
demulsifiers, separating out water, sand or grit present in the slop oil;
(iii) degreasers; and, (iv) pour point depressants (Specification at
10:2-15).
[8] The wax is said to be dispersed as hydrocarbon into the crude oil
(Specification at 10:15-16).
[9] Keeping the wax dispersed in the crude oil is said to lower
maintenance costs and downtimes due to pipeline clogging and
corrosion and to increase the throughput and flow rate of crude oil
through the pipelines (Specification at 11:4-11).
[10] A preferred chemical dispersant is a homogenous mixture of (a)
about 25% to about 99.5% by weight surface active agent, (b) about
15% to about 35% by weight butyl cellosolve (i.e., 2-butoxy-ethanol),
and (c) about 5% to about 15% by weight of (i) pine oil and (ii) a
catalyst made of saturated higher fatty acids, an alkylphenol and an
oil-water soluble copolymer of partially sulfonated, maleic anhydride
and polystyrene with a molecular weight ranging from about 2,000 to
4
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