Catalytic reactor and associated operating method

1. A catalytic reactor for generating a hydrogen-containing synthesis gas from a rich fuel/oxidizing agent mix, comprising:

a multiplicity of parallel passages which each extend from an inlet side to an outlet side;

all the passages being catalytically active at least in a core region of a cross section though the reactor;

a catalytically active coating on surfaces of the passages which are to be exposed to the gas flow;

the multiplicity of passages comprising catalytically active first and second passages, the catalytically active first passages being in a first longitudinal part of the reactor which includes the inlet side, the first passages having a greater proportion of the surface area provided with catalytically active coating than the catalytically active second passages, the second passages being in a second longitudinal part of the reactor which includes the outlet side and adjoins the first longitudinal part.

2. The reactor as claimed in claim 1 , wherein the surfaces of the first passages are completely provided with a catalytically active coating, and the surfaces of the second passages are only partially provided with a catalytically active coating.

3. The reactor as claimed in claim 1 , further comprising:

common walls separating from one another passages which are transversely adjacent; and

wherein the walls in the first passages are catalytically active on two sides, the walls in the second passages are catalytically active on one side, or both.

4. The reactor as claimed in claim 1 , wherein the hydraulic diameter of the first passages is greater than the hydraulic diameter of the second passages.

5. The reactor as claimed in claim 1 , wherein:

the axial length of the first passages is between four and twenty-five times greater than the hydraulic diameter of one of the first passages;

the axial length of the second passages is between twenty-five and one hundred times greater than the hydraulic diameter of one of the second passages;

or both.

6. The reactor as claimed in claim 1 , wherein:

the second longitudinal part directly adjoins the first longitudinal part; or

the second longitudinal part is at an axial distance from the first longitudinal part, with the distance between the first and second longitudinal parts being less than five times the hydraulic diameter of one of the first passages or of one of the second passages.

7. The reactor as claimed in claim 1 , further comprising:

an annular region coaxially surrounding the core region and catalytically inactive passages in the first longitudinal part and in the second longitudinal part.

8. An assembly comprising:

a premix burner having a head;

a lance arranged concentrically in the head and projecting into the premix burner;

a reactor installed in the lance, the reactor comprising

a multiplicity of parallel passages which each extend from an inlet side to an outlet side;

all the passages being catalytically active at least in a core region of a cross section though the reactor;

a catalytically active coating on surfaces of the passages which are to be exposed to the gas flow; and

the multiplicity of passages comprising catalytically active first and second passages, the catalytically active first passages being in a first longitudinal part of the reactor which includes the inlet side, the first passages having a greater proportion of the surface area provided with catalytically active coating than the catalytically active second passages, the second passages being in a second longitudinal part of the reactor which includes the outlet side and adjoins the first longitudinal part.

9. A burner arrangement, comprising:

a combustion chamber having an exit side;

a main fuel feed connected to the combustion chamber;

a main oxidizing agent feed connected to the combustion chamber;

at least one catalytic reactor connected to the combustion chamber on the exit side;

an additional fuel feed connected to the reactor;

an additional oxidizing agent feed connected to the reactor; and

a heating device for preheating the fuel, the oxidizing agent, or both, upstream of the reactor;

wherein the at least one catalytic reactor comprises

a multiplicity of parallel passages which each extend from an inlet side to an outlet side;

all the passages being catalytically active at least in a core region of a cross section though the reactor;

a catalytically active coating on surfaces of the passages which are to be exposed to the gas flow; and

the multiplicity of passages comprising catalytically active first and second passages, the catalytically active first passages being in a first longitudinal part of the reactor which includes the inlet side, the first passages having a greater proportion of the surface area provided with catalytically active coating than the catalytically active second passages, the second passages being in a second longitudinal part of the reactor which includes the outlet side and adjoins the first longitudinal part.

10. The reactor as claimed in claim 4 , wherein the hydraulic diameter of the first passages is double the hydraulic diameter of the second passages.

11. A burner arrangement as claimed in claim 9 , configured and arranged for a gas turbine of a power plant.