Multi-tubular chemical reactor with igniter for initiation of gas phase exothermic reactions

A method of carrying out a gas phase exothermic reaction within a multi-tubular chemical reactor to produce desired product(s), the method comprising:

• introducing gaseous reactants into an inlet of a gaseous flow passageway of a plurality of reactor units, each reactor unit of the plurality comprising an elongate tube having a wall with an internal surface, an external surface, and a wall interior between the internal and external surfaces, at least a portion of the wall interior adapted to function as a gas phase reaction zone, the interior surface of the wall enclosing the gaseous flow passageway having the inlet at one end and an outlet at the opposing end, the interior surface of the wall adapted to permit gas flowing through the passageway to enter the wall interior at the gas phase reaction zone;
• flowing at least a portion of the gaseous reactants into the as phase reaction zones of the plurality of reactor units;
• initiating with radiant heat an exothermic reaction of the gaseous reactants within the gas phase reaction zone of at least one of the reactor units, thereby commencing the production of desired product(s) and exothermic heat;
• and
• transferring heat produced by the exothermic reaction occurring within the gas phase reaction zone of the at least one reactor unit to the gas phase reaction zone of one or more adjacent reactor units, thereby initiating an exothermic reaction within the at least one adjacent reactor unit until in such manner an exothermic reaction has been initiated in each of the plurality of spaced-apart reactor units.