This paper presents a new Composite Adaptive Controller for trajec- tory tracking and disturbance compensation on the basis of a second-order continuous anaerobic digestion model. The proposed controller comprises an Algebraic Di erential Estimation based compensation component and a Re- cursive Model Free Controller based stabilization component which does not require any knowledge of the model parameters. The proposed entire con- trol overperforms existing anaerobic digestion control schemes such as classical Proportional-Integral-Derivative control or a nonlinear PI control. Computer simulation examples illustrate the performance and robustness of the proposed approach.