Abstract: A process for selectively converting a dialkyl ether to the corresponding alkene and alkanol comprises contacting a feed containing at least one dialkyl ether with a catalyst comprising a mixed metal oxide which comprises at least one metal selected from Group 4 of the Periodic Table of Elements and at least one metal selected from Group 3 (including the Lanthanides and Actinides) and Group 6 of the Periodic Table of Elements.
Type:
Grant
Filed:
December 16, 2004
Date of Patent:
September 5, 2006
Assignee:
ExxonMobil Chemical Patents Inc.
Inventors:
Doron Levin, Shifang Luo, James Clarke Vartuli, Charles Morris Yarbrough, Dane Clark Grenoble
Abstract: Disclosed is a process for purifying 2,6-naphthalene dicarboxylic acid produced by disproportionation and more efficiently recycling byproduct dipotassium salts which includes the steps of:
a) Contacting an aqueous solution containing the disalt of 2,6-NDA(2,6-K2NDA) with carbon dioxide to form as a precipitate the monopotassium salt of 2,6-NDA (KHNDA) and an aqueous solution containing 2,3-KHNDA, K2NDA, and potassium bicarbonate;
b) Disproportionating said monopotassium salt (KHNDA) to form 2,6-NDA and an aqueous solution containing K2NDA, and potassium bicarbonate;
c) Separating said 2,6-NDA and concentrating said aqueous solution containing K2NDA and potassium bicarbonate by reverse osmosis.
Abstract: Compounds having the structure ##STR1## wherein Z--COO).sub.m is the residue of a polyiodinated aromatic acid; m is 1, 2, 3 or 4;n is an integer from 1 to 20;R.sup.1 and R.sup.2 are independently H, alkyl, fluoroalkyl, cycloalkyl, aryl, aralkyl, alkoxy or aryloxy;R.sup.3 and R.sup.4 are independently H, alkyl, fluoroalkyl, cycloalkyl, aryl, aralkyl, alkoxy, aryloxy, halogen, hydroxy or acylamino; andR.sup.5 is H, alkyl, cycloalkyl, aryl, aralkyl, alkoxyalkyl or acetamidoalkyl;are useful as contrast agents in x-ray imaging compositions and methods.
Type:
Grant
Filed:
June 20, 1994
Date of Patent:
November 14, 1995
Assignee:
Eastman Kodak Company
Inventors:
Edward R. Bacon, Sol J. Daum, Paul P. Spara
Abstract: A fuel cell electrolyte with an electrochemically inactive matrix, an electrochemically active electrolyte, and a substantially gas impervious metallic foil in the central region of the thickness of the electrolyte extending around its periphery over at least a portion of the fuel cell peripheral seal area and into the electrolyte active area reducing gas crossover between the anode and cathode chambers. The gas impervious metallic foil may extend beyond the periphery of the electrolyte into the fuel cell peripheral seal area and have a resilient gasket on each side forming the fuel cell peripheral seal with seal structures extending from separator plates, thereby eliminating conventional electrolyte wet seals. The seal structures according to this invention are also suitable for sealing internal manifolds in fuel cell stacks.
Type:
Grant
Filed:
October 20, 1992
Date of Patent:
March 29, 1994
Assignee:
M-C Power Corporation
Inventors:
Rene M. Laurens, Thomas G. Benjamin, Robert P. Bachta