Appeal No. 1998-0558
Application No. 08/564,942
effluent;
(e) subjecting at least a portion of the
first hydrocarbon-rich fraction to the
contacting of step (c);
(f) increasing system pressure of the
hydrogen rich fraction, said hydrogen rich
fraction having vaporous light hydrocarbon
impurities, said increase in system
pressure
high enough to cause a phase change in the
vaporous light hydrocarbon impurities from
a vapor to a liquid phase, whereby said
phase change causes an increase in hydrogen
purity in the recycle stream; and
(g) recovering at least one C alkyl
8
aromatic product from the second fraction.
The examiner relies upon the following references as
evidence of obviousness:
Riehm 4,139,571 Feb. 13, 1979
Berger, et al. (Berger) 3,553,276 Jan. 05, 1971
Yamasaki et al. (Yamasaki) 4,300,014 Nov. 10, 1981
Appellant's claimed invention is directed to a process
for isomerizing a C alkyl aromatic hydrocarbon-containing
8
feedstock, such as one containing ethylbenzene, to produce
compounds such as paraxylene, although none of the appealed
4
Page: Previous 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Next
Last modified: November 3, 2007