Abstract: A process and apparatus are disclosed to achieve high per-pass synthesis conversion of ammonia. A nitrogen/hydrogen synthesis gas mixture is passed sequentially through a plurality of catalyst beds. The effluent from a subsequent catalyst bed is cooled by direct quench with a partially reacted gas which has passed through at least a first catalyst bed.

Abstract: An apparatus for the synthesis of ammonia having at least two synthesis reactors in series in which two high temperature heat sink tube bundles are combined in a single shell which is close coupled to the inlet and outlet of a reactor, the second tube bundle being disposed in an interior portion of the exchanger shell inside of the first tube bundle, the first tube bundle being connected for flow from its tubes to the reactor inlet, the second tube bundle being connected for flow to its tubes from the reactor outlet.

Abstract: A method of making high purity sulfur dioxide by submerged combustion is disclosed. Sulfur is combusted in a first liquid pool with an oxygen-containing gas and the vapor effluent is removed and cooled in a first cooling zone to a temperature above approximately 600.degree. F. The condensed sulfur is separated as liquid sulfur from the vapor in the cooled effluent and passed back to the reactor as the supply of liquid sulfur for conversion to sulfur dioxide.

Abstract: Apparatus is disclosed for synthesizing ammonia from an ammonia feed gas passing to an ammonia synthesis converter from a heat exchanger. The synthesis converter is close coupled through a channel to a heat exchanger and a conduit extends through the channel and is adapted to be connected to the tube side of the heat exchanger.

Abstract: A combined heat exchanger particularly suited for ammonia converter reactor effluent is described. The combined exchanger includes a first exchanger and a high temperature heat sink, such as a steam superheater, within a single exchanger shell. In a preferred embodiment, gas leaving the ammonia converter is conveyed into a single pass tube bundle which comprises the feed-effluent exchanger section and then passes through a tubesheet which separates the feed effluent exchanger section from the steam superheater section, passing over a U-tube bundle which comprises the steam superheater section in the other part of the shell. Means are provided for protecting the shell in the steam superheater section adjacent the tubesheet.