Apparatus and process for heat exchange with fluid beds

Apparatus for reacting at least one reactant with molecular oxygen-containing gas in the presence of a fluidised bed of catalyst which apparatus comprises a reactor having:

• (a) means for fluidising a bed of fluidisable catalyst within a fluidisation zone in the reactor;
• (b) means for introducing at least one reactant into the reactor;
• (c) means for introducing a molecular oxygen-containing gas into a fluidised bed of catalyst in the fluidisation zone in the reactor and contacting the at least one reactant with the molecular oxygen-containing gas in the presence of the fluidised bed of catalyst in the fluidisation zone;
• and
• (d) heat-exchange tubes located in the fluidisation zone longitudinally with respect to the axis of the fluidisation zone with a rectangular pitch, one side of which having a length at least one and a half times the length of the other side and/or with a triangular pitch, having two sides each at least one and a half times the length of the shortest side.

A process for reacting at least one reactant with molecular oxygen-containing gas in the presence of a fluidised bed of catalyst which process comprises:

• (a) fluidising a bed of fluidisable catalyst within a fluidisation zone in a reactor having means for supporting the fluidised bed of catalyst;
• (b) introducing at least one reactant into the reactor;
• (c) introducing a molecular oxygen-containing gas into the fluidised bed of catalyst in the fluidisation zone in the reactor;
• (d) contacting the at least one reactant with the molecular oxygen-containing gas in the presence of the fluidised bed of catalyst in the fluidisation zone;
• and
• (e) removing at least part of the heat of reaction from the fluidisation zone by heat-exchange tubes located in the fluidisation zone longitudinally with respect to the axis of the fluidisation zone with a rectangular pitch, one side of which having a length at least one and a half times the length of the other side and/or with a triangular pitch, having two sides each at least one and a half times the length of the shortest side.