Bio Adipic Acid Production from Sodium Muconate and Muconic Acid: A Comparison of two Systems

sodium muconate and trans,trans-muconic acid were heterogeneously hydrogenated to adipic acid, a strategic intermediate for the industry of polyamides and high performance polymers. Hydrogen pressure, metal to substrate ratio, substrate concentration and reaction temperature were varied to study the effect of these parameters on the reaction products. Commercial Pd/AC 5 % was used as catalyst and characterized by TEM, BET and XPS analyses. The results revealed that temperature is the parameter which mainly affect the reaction. Moreover, hydrogenation of trans,trans-muconic acid is faster than sodium muconate reduction. Full conversion and full yield toward adipic acid was obtained using trans,trans-muconic acid as substrate after 60 min at the following operating conditions: temperature=70 °C, metal/substrate=1/200 (molPd/molsub), trans,trans-muconic acid concentration=1.42E-02M and hydrogen pressure=1 bar. In all reactions (2E)hexenedioic acid was detected as main intermediate.