Apparatus and process for oxidant formation

A process for forming an oxidant, the process comprising:

• forming an oxidant by mixing carrier gas from at least one source of gas and/or flue gas recycled from a combustion device with oxygen from at least one source of oxygen;
• and
• feeding the formed oxidant to the combustion device as an oxidant for combustion of a fuel in a combustion chamber of the combustion device;
• wherein the mixing of the carrier gas with the oxygen is performed via a mixing device, the mixing device comprising:
• a plurality of injection devices positioned within a conduit of the mixing device, the injection devices positioned and configured to inject the oxygen into the carrier gas to form the oxidant;
• and
• the injection devices including a central region of injection devices, a first outer region of injection devices positioned between the central region of the injection devices and a first sidewall of the conduit and a second outer region of injection devices positioned between the central region of the injection devices and a second sidewall of the conduit;
• and
• the central region of injection devices being positioned between the first outer region of injection devices and the second outer region of injection devices.

A combustion apparatus comprising:

• a combustion device;
• a mixing device positioned and configured to receive a carrier gas from at least one source of gas and/or flue gas recycled from the combustion device, the mixing device also positioned and configured to receive oxygen from a source of oxygen for injecting the oxygen into the carrier gas to form an oxidant for feeding to the combustion device;
• at least one flow conditioning device positioned upstream of the mixing device;
• the mixing device comprising a plurality of injection devices positioned within a conduit of the mixing device, the injection devices positioned downstream of the at least one flow conditioning device such that the carrier gas is passable through the at least one flow conditioning device before passing along the injection devices;
• the at least one flow conditioning device configured to provide a uniform velocity profile for the carrier gas passed along the injection devices along a cross-section of the conduit;
• the injection devices positioned and configured to inject the oxygen into the carrier gas to form the oxidant;
• the injection devices including a central region of injection devices, a first outer region of injection devices positioned between the central region of the injection devices and a first sidewall of the conduit and a second outer region of injection devices positioned between the central region of the injection devices and a second sidewall of the conduit;
• the central region of injection devices being positioned between the first outer region of injection devices and the second outer region of injection devices;
• each of the injection devices of the central region of injection devices being configured to inject a mass flow rate of oxygen into the carrier gas via a central region injection rate,
• each of the injection devices of the first outer region of injection devices being configured to inject a mass flow rate of oxygen into the carrier gas via an outer region injection rate,
• each of the injection devices of the second outer region of injection devices being configured to inject a mass flow rate of oxygen into the carrier gas via the outer region injection rate, and
• the central region injection rate being at least 5% greater than the outer region injection rate;
• and
• wherein a duct aspect ratio of the conduit is between 3 and 5.