Two-stage combustor

A two-stage combustor comprising a housing having disposed therein:

• (a) a partial oxidation reactor comprising the following components:
• (i) a fuel inlet for feeding a hydrocarbon fuel into a reaction zone,
• (ii) a first oxidant inlet for feeding a first supply of an oxidant into a reaction zone,
• (iii) a reaction zone comprising a mesh substrate having an ultra-short-channel-length and having a partial oxidation catalyst supported thereon;
• the reaction zone being disposed in fluid communication with the fuel inlet and the first oxidant inlet;
• and
• (iv) an outlet fluidly connected to the reaction zone for exhausting a partial oxidation reaction product;
• and
• (b) a deep oxidation reactor comprising the following components:
• (i) a premixer plenum having an upstream end and a downstream end;
• wherein at the upstream end the premixer plenum is fluidly connected to the outlet of the reaction zone;
• and further wherein the premixer plenum comprises a second oxidant inlet for feeding a second supply of an oxidant into the premixer plenum;
• wherein the premixer plenum contains a foam matrix of metallic or ceramic composition having a higher pore density than a pore density of the foam matrix of the heat spreader;
• (ii) a heat spreader having an upstream end and a downstream end;
• wherein at the upstream end the heat spreader is fluidly connected to the downstream end of the premixer plenum;
• and further wherein the heat spreader comprises a metal foam matrix provided in an annular shape defined by an inner diameter and an outer diameter;
• and
• (iii) an outlet pathway fluidly connected to the downstream end of the heat spreader for exhausting a gaseous combustion product.

A process of combusting a hydrocarbon in a two-stage combustor, comprising:

• (a) in a partial oxidation reactor, contacting a hydrocarbon fuel and a first oxidant with a reforming catalyst supported on a porous substrate under fuel-rich conditions sufficient to produce a product mixture comprising hydrogen and carbon monoxide;
• (b) passing the product mixture into a premixer plenum where the product mixture is charged with a second oxidant to form a fuel-lean combustion mixture;
• (c) combusting the fuel-lean combustion mixture in a foam matrix heat spreader under fuel-lean conditions sufficient to form carbon dioxide and water and heat of reaction;
• wherein the fuel-lean combustion mixture has a superficial velocity through the foam matrix heat spreader ranging from 20 cm/sec to 60 cm/sec.

A process of combusting a hydrocarbon in a two-stage combustor, comprising:

• (a) in a partial oxidation reactor, contacting a hydrocarbon fuel and a first oxidant with a reforming catalyst supported on a porous substrate under fuel-rich conditions sufficient to produce a product mixture comprising hydrogen and carbon monoxide;
• (b) passing the product mixture into a premixer plenum where the product mixture is charged with a second oxidant to form a fuel-lean combustion mixture;
• (c) combusting the fuel-lean combustion mixture in a foam matrix heat spreader under fuel-lean conditions sufficient to form carbon dioxide and water and heat of reaction;
• wherein the fuel-lean combustion mixture has a velocity ranging from 10,000 hr−1 to 50,000 hr−1 through the foam matrix heat spreader.