Burner and process for producing synthesis gas
A burner for producing synthesis gas by partial oxidation of liquid or gaseous, carbon-containing fuels in the presence of an oxygen-containing oxidant and a moderator, which burner can be operated uncooled, i.e. without a fluid coolant being passed through the burner, is proposed. Steam or carbon dioxide or else mixtures of these materials are used as moderator. This is achieved by the feed channels being configured so that mixing of the fuel, the moderator and the oxidant occurs only outside the burner.
1. The process for producing a synthesis gas comprising hydrogen and carbon oxides by partial oxidation of liquid or gaseous, carbon-containing fuel in the presence of an oxygen-containing oxidant and a moderator containing steam and/or carbon dioxide, comprising the following steps:
(a) providing a burner, wherein the burner comprises:
means for separately feeding in the carbon-containing fuel, the oxygen-containing oxidant and the moderator,
a central first feed channel having a circular cross section,
a second feed channel which coaxially and concentrically surrounds the first feed channel, forming an annular gap between an outer wall of the first feed channel and an inner wall of the second feed channel,
a third feed channel which coaxially and concentrically surrounds the second feed channel, forming an annular gap between an outer wall of the second feed channel and an inner wall of the third feed channel, wherein an outer wall of the burner is formed by an outer wall of the third feed channel, and
an absence of cooling fluid channel disposed outside of the third feed channel;
(b) feeding of the oxygen-containing oxidant to the first feed channel, of the moderator to the second feed channel and of the liquid or gaseous, carbon-containing fuel to the third feed channel;
(c) discharging, without having been mixing therein, the carbon-containing fuel, the oxygen-containing oxidant, and the moderator from the burner and introducing the carbon-containing fuel, the oxygen-containing oxidant, and the moderator into a reaction chamber downstream of the burner;
(d) reacting the carbon-containing fuel with the oxygen-containing oxidant in the reaction chamber under conditions of partial oxidation; and
(e) discharging a crude synthesis gas from the reaction chamber,
wherein the outer wall of the third feed channel, the dividing wall between the second feed channel and the third feed channel and the dividing wall between the first feed channel and the second feed channel end in a common plane which runs perpendicularly to the longitudinal axis of the burner and forms the burner mouth,
wherein the feed channels are configured so that mixing of the fuel, the moderator, and the oxidant occurs only outside the burner.
2. The process of claim 1 , further comprising the absence of a step of passing a fluid coolant through the burner.
3. The process of claim 2 , wherein at least two of the feed channels are equipped with swirl-inducing devices, where the directions of rotation imparted to the media flowing through the at least two feed channels are counter to one another relative to the longitudinal axis of the burner.
4. The process of claim 1 , wherein at least one of the feed channels is equipped with a swirl-inducing device.
5. The process of claim 4 , wherein all feed channels are equipped with swirl-inducing devices, where the directions of rotation of the media which flow through the first feed channel and the third feed channel are the same relative to the longitudinal axis of the burner and the direction of rotation of the moderator flowing through the second feed channel is counter thereto.
6. The process of claim 1 , wherein the exit velocity of the moderator from the burner mouth is in the range from 20 to 200 m/s.
7. The process of claim 1 , wherein the ratio of the exit velocities of moderator to oxidant is in the range from 0.2 to 2.5.
8. The process of claim 1 , wherein the ratio of exit velocities of moderator to fuel is in the range from 0.2 to 2.0.
9. The process of claim 1 , wherein the exit velocity of the moderator is kept constant when the exit velocity of the oxidant and/or of the fuel is reduced.
10. The process of claim 1 , wherein carbon dioxide is separated off from the crude synthesis gas in at least one of the further conditioning or processing steps and at least partly recirculated as moderator to the burner.
11. The process of claim 1 , further comprising introducing the crude synthesis gas into further conditioning or processing steps.