Appeal No. 97-3640
Application No. 08/406,272
problem with this approach is that the water vapor from the solution is introduced into
the ethylene, thus necessitating zeolite water-absorption beds which (i) would be large
and costly to install; and (ii) would be expensive to regenerate. (col. 2, lines 24-45)
Accordingly, Jones removes trace amounts of carbon dioxide from olefin gases by passing the gas
through an essentially non-aqueous liquid solution of alkali or alkaline earth metal hydroxides and/or
weak acid salts and certain selected liquid polyhydric alcohols (abstract). In cases where the ethylene
feed also contains trace amounts of water, a potassium-based system eliminates the need for water-
removing adsorbents or at least reduces their size considerably (col. 14, lines 25-34).
According to the examiner,
[i]t would have been obvious to one of ordinary skill in the art at the time the
invention was made to have contacted a fluid comprising ethylene, CO and water with
2
a soda-lime product such as is disclosed in McKernan, in order to remove CO ,
2
because McKernan teaches that CO should be removed from ethylene in order not to
2
poison downstream catalysts, and because Jones teaches that there exist fluids
comprising CO , water, and ethylene from which CO should be removed prior to2 2
catalytic polymerization into polyethylene.
With respect to the weight ratio of CO to fluid recited in claim 23, note that
2
Jones teaches CO as being present in 10-25 ppm (col. 2, lines 24-25), which falls into
2
the broad range claimed. (Ans. page 6, last two paragraphs)
Appellant argues neither McKernan, nor Jones, nor the combination of McKernan and Jones,
disclose or suggest (i) contacting a water-containing fluid with a substantially solid composition (Br.
page 12, last paragraph) or (ii) the positive step of adding water to an olefin fluid to improve CO2
removal and contacting the resulting water-containing fluid with a composition such as soda lime (Br.
page 13, paragraph two). Appellant submits the examiner not only continues to ignore the step of
Page 11
Page: Previous 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 Next
Last modified: November 3, 2007