Abstract: Apparatus for the detection of carbon monoxide concentration of a gas. The apparatus comprises a base from which a pair of arms extend, a resistance layer disposed on each arm serving both to measure the difference in temperature between the arms and to heat a catalyst layer; a protective layer on the resistance layers to prevent electrical shorts caused by deposit of conductive particles in the gas to be detected; and a catalyst layer on one and only one of the arms in contact with the protective layer.

Abstract: Apparatus for detecting the concentration of a gas by measuring the amount of mercury vapor generated when the gas is passed through a mercuric oxide bed. The apparatus includes a body having a central bore therein with a quartz rod at one end for directing ultraviolet light from a source through the central bore. A second quartz rod at the opposite end of the central bore directs the ultraviolet light to a detector coupled to an electronics circuit for analysis purposes. A fitting coupled to the body has a gas inlet port and a passage from the port to the central bore of the body. The mercuric oxide bed is across the passage so that the gas, in passing through the bed, causes mercury vapor to be generated and to pass into the central bore of the body. The amount of mercury vapor is measured by its spectral absorption in the ultraviolet range when the mercury vapor is in the central bore of the body.

Abstract: In a selective hydrogenation process wherein at least two catalyst beds in series are utilized, the temperature of the feed stream flowing to the first catalyst bed and the temperature of the feed stream flowing from the first catalyst bed to the second catalyst bed are controlled using a combination of feed forward and feed back control. The feed forward control is based on the change in a process variable during a specified period of time. The feed back control is based on a comparison to the actual concentration of acetylene in the product stream flowing from the second catalyst bed to the desired concentration of acetylene in the product stream flowing from the second catalyst bed.