A method includes blending a first fuel with a second fuel in a ratio to produce a third mixed fuel. The first fuel has a first heating value, the second fuel has a second heating value, and the third mixed fuel has a third heating value. In addition, the first heating value is different than the second heating value. The method also includes feedforward controlling the third heating value of the third mixed fuel via prediction and correction of a fuel flow rate of the first and/or second fuels to adjust the ratio of the first and second fuels based at least in part on a comparison between a measurement and a target for the third heating value.