Pramod K. Sharma

Copper modified carbon molecular sieves for selective oxygen removal

Carbon molecular sieves modified by the incorporation of finely divided elemental copper useful for the selective sorption of oxygen at elevated temperatures. The carbon molecular sieves can be regenerated by reduction with hydrogen. The copper modified carbon molecular sieves are prepared by pyrolysis of a mixture of a copper-containing material and polyfunctional alcohol to form a sorbent precursor. The sorbent precursors are then heated and reduced to produce copper modified carbon molecular sieves. The copper modified carbon molecular sieves are useful for sorption of all concentrations of oxygen at temperatures up to about 200° C. They are also useful for removal of trace amount of oxygen from gases at temperatures up to about 600° C.

Thermal outgassing behavior and photoemission studies of Haynes Alloy 214

Processing of many materials at high temperatures requires a high purity environment. The outgassing from hot surfaces of the processing chamber or the heating elements is a potential problem. The total amount of outgassing as well as the time‐ and temperature‐ dependent outgassing rates are important. The outgassing from Haynes Alloy 214 has been studied experimentally under a vacuum in the temperature range from room temperature to 600u2009°C. In addition to the outgassing rates, the composition of the outgassed species was determined through mass spectrometric analysis. Alloy surface composition was determined by x‐ray photoelectron spectroscopy. Changes in surface composition before and after heating can be accounted for by the outgassed species.

Selective molecular sorption by high surface area catalyst supports

Abstract Three high surface area catalyst supports were studied for the selective molecular sorption of organic compounds. The first was a carbon molecular sieve with a well-defined pore structure. The other two were silica gel and high surface area alumina. Both have a random pore structure. A mixture of phenol and acetic acid was used to qualitatively characterize the intermolecular force potentials and pore selectivity. Thermal gravimetric analysis and mass spectroscopy were used to characterize the desorption kinetics and differential scanning calorimetry was used to study the heats of desorption. The analyses illustrate an approach for characterizing adsorption-desorption processes in catalysts and high surface area materials.

A comparison of the oxygen uptake characteristics of copper-exchanged zeolite with copper dispersed on a silica support

Abstract The kinetics of activated oxygen uptake by copper dispersed on catalytic supports was investigated. Two different adsorbents for oxygen were prepared: (a) Linde zeolite 13X was ion exchanged to replace sodium by copper, resulting in a uniform addition of copper to the zeolite; (b) dried silica gel was impregnated with copper oxide. The adsorbents were reduced by hydrogen to convert the copper oxide to elemental copper. The oxygen uptake by the reduced adsorbents was studied with the aid of a thermogravimetric analyser in the temperature range from 20 to 400°C. Global rate expressions were obtained from the kinetic data. Some insight into the role of the support in activating the copper oxidation was obtained from the rate expressions.

Surfactant studies for bench-scale operation

A phase II study has been initiated to investigate surfactant-assisted coal liquefaction, with the objective of quantifying the enhancement in liquid yields and product quality. This publication covers the first quarter of work. The major accomplishments were: (1) the refurbishment of the high-pressure, high-temperature reactor autoclave, (2) the completion of four coal liquefaction runs with Pittsburgh [number sign]8 coal, two each with and without sodium lignosulfonate surfactant, and (3) the development of an analysis scheme for the product liquid filtrate and filter cake. Initial results at low reactor temperatures show that the addition of the surfactant produces an improvement in conversion yields and an increase in lighter boiling point fractions for the filtrate.