System and method for controlling the calorie content of a fuel

The present invention pertains generally to a system 10 and method for providing fuel having a desired calorie content 54 to a combustion engine 46 over a range of operating levels. The system 10 mixes a first fuel from a first fuel supply pipe 20 with a second fuel from a second fuel supply pipe 22 at a mixing point 26 to create a mixed fuel having a first calorie content. A control valve 24 is located in the second fuel supply pipe upstream of the mixing point 26. A process system downstream of the mixing point 26 processes the mixed fuel to create a processed mixed fuel having a second calorie content. A first control signal 42 is reflective of the first calorie content of the mixed fuel. A second control signal 44 is reflective of the second calorie content of the processed mixed fuel. A third control signal is reflective of the operating level of the combustion engine. A controller 40 connected to the control valve operates the control valve 24 based on the first, second, and third control signals 42, 44, 46.