Abstract: A vapor-liquid contacting tower having a tray deck, at least one downcomer and a structure packing layer in the space under the vapor-liquid bubble contacting tray wherein the tray deck has an opening such that vapor ascends upward through the opening to come into contact with the liquid flowing across the tray deck to form a froth in which the vapor and the liquid on the tray deck creates cross-flow bubble contact and with the structural dimensions of the tray deck and downcomer providing for at least 90 vol % of the total liquid flowing across the tray deck flows downwardly through the downcomer to the adjacent deck.

Abstract: This invention relates to a catalyst for ammonia synthesis. The main phase of the catalyst is a non-stoichiometric ferrous oxide expressed as Fe.sub.1-x O, which is structurally in a Wustite crystal phase form having the rock salt face-centered cubic lattice with lattice paracueter of 0.427-0.433 nm. This catalyst, which has quick reduction rate and high activity, and remarkably lowers the reaction temperature, is especially applicable as an ideal low-temperature, low-pressure ammonia synthesis catalsyt and can be widely used in ammonia synthesis industry.