Abstract: Adhesive-backed graphite foil rings (62,64) are suited to forming a seal between a metal gasket plate (12) and adjacent pipe flanges (40, 42). To form the rings, a thin layer of adhesive (74) is applied in the form of a coating to a flexible graphite sheet (70). A release liner (80) may be applied over the adhesive layer. The rings (62,64) are cut from the adhesive coated flexible graphite sheet. In one method, the rings are die cut while leaving the release liner intact. After removal of extraneous material, a plurality of the rings remain attached to the release liner and can be peeled away from the liner as needed. In another method, a central cut-out portion (102) from a large adhesive-backed ring is later used to form a smaller adhesive-backed ring.

Abstract: An integrated process for regenerating a deactivated or partially deactivated alkylation catalyst comprising fluorosulfuric acid which comprises:(1) contacting said fluorosulfuric acid with water to form an acid-water mixture, thereby converting at least a portion of the fluorosulfuric acid therein to hydrogen fluoride and sulfuric acid;(2) removing at least a portion of the hydrogen fluoride from said acid-water mixture formed in step (1) by contacting same with a paraffin to form a gaseous phase containing hydrogen fluoride and said paraffin;(3) cooling the gaseous phase formed in step (2) by contacting with liquid paraffin to condense a portion of the fluorosulfuric acid present in said gaseous phase, thereby forming a liquid phase and a gaseous phase each containing fluorosulfuric acid and hydrogen fluoride;(4) treating the liquid and gaseous phases formed in step (3) with liquid sulfur trioxide to form a mixture comprising a liquid phase containing regenerated fluorosulfuric acid and a gas phase containi