Abstract: A process for the catalytic decomposition of dinitrogen monoxide in a gas stream by contacting the gas stream at temperatures of 200.degree.-900.degree. C. and pressures of 0.1 to 20 bar with a catalyst free of noble metals, the catalyst being prepared by combining a spinel CuAl.sub.2 O.sub.3 with another spinel-forming metal component selected from the group consisting of tin, lead, zinc, magnesium, calcium, strontium and barium or mixtures thereof in elemental form or as an oxide or salt, and calcining at temperatures of 300.degree.-1300.degree. C. and under pressures of 0.1-200 bar in order to at least partially liberate the copper from the spinel by replacement with the other metal component.

Abstract: Caprolactam is obtained from caprolactam-containing polymers in the presence of a base under reduced pressure by depolymerizing polymers which contain the repeating unit --[--N(H)--(CH.sub.2).sub.5 --C(O)--] or mixtures consisting essentially offrom 50 to 99.99% by weight of a polymer containing the repeating unit --[--N(H)--(CH.sub.2).sub.5 --C(O)--]--from 0.01 to 50% by weight of additives selected from the group consisting of inorganic fillers, organic and inorganic pigments and dyes,from 0 to 10% by weight of organic and/or inorganic additives,from 0 to 40% by weight of non-polyamide-containing polymers andfrom 0 to 20% by weight of polyamides, with the exception of polycaprolactam and copolyamides prepared from caprolactam,in at least two depolymerization reactors connected in series.

Abstract: Nitrous oxide is removed from gases containing hydrogen, nitric oxide and nitrous oxide by a process in which the gases are treated with molecular sieves.