Shell Oil Comapny

Chaoliang Yao

Charles C Chou

Dennis C Krueger

A passive dosimeter with a structurally reinforced sorbent wafer is used for monitoring a worker's exposure to ambient aromatics (benzene, toluene, ethylbenzene and xylenes). The wafer is preferably formed by pressing 4 mg of sorbent material between two pieces of 100 mesh stainless steel wire gauze. The thickness of the formed pellet is about 1 mm. The wafer sorbent material design produces a much smaller background noise on gas chromatographic (GC) analysis and enhances the signal-to-noise ratio during the thermal desorption process. This enables the detection of a much lower concentration level of ambient air contaminants than other types of passive dosimeters designed for thermal desorption analysis.

Thermally desorbable passive dosimeter

A process for removing Total Reduced Sulfur compounds from a gaseous stream such as those containing natural gas, industrial gas, and digester gas by oxidation with a fine flocculent acidic catalyst slurry which is regenerable during the process by pH adjustment in the absence of added heat. The catalyst slurry comprises MnO.sub.2, Mn.sub.2 O.sub.3, and Mn.sub.3 O.sub.4 having pH in the range from about 0.5 to about 6.5 and is prepared by oxidizing a divalent manganous salt in an aqueous solution having a pH in the range from about 8.0 to about 13.5 with an oxygen-containing gaseous stream.

Process for removing total reduced sulfur compounds from gaseous stream

A process for removing NO.sub.x and/or SO.sub.x from a gaseous stream by oxidation with a fine flocculent acidic catalyst slurry which is regenerable during the process, in particular by pH adjustment in the absence of added heat. The catalyst slurry comprises MnO.sub.2, Mn.sub.2 O.sub.3, and Mn.sub.3 O.sub.4 having pH in the range from about 0.5 to about 6.5 and is prepared by aerating a divalent manganous salt in an aqueous solution having a pH in the range from about 8.0 to about 13.5.

Process for removing nitrogen oxides and sulfur oxides from gaseous

A stainless steel exposure chamber utilizes either a gas cylinder standard or a permeation tube standard to generate the required test atmosphere. The concentrations of the contaminants in the chamber can be varied from lower parts per billion (ppb) to high parts per million (ppm) levels. The system is capable of testing several types of industrial hygiene samplers at the same time, under the same chamber conditions and at different orientations of the samplers. The chamber is also useful for the development and verification of industrial hygiene air-monitoring methods.

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Houston, TX, United States of America

Chaoliang Yao