Press Mud or filter cake is a by-product of sugar industry
Press mud, a solid waste obtained from the sugar mills, contains 1.2%N, 2.1-2.4% P2O5, 2.0% K2O, 238-288 ppm Zn and 112-132 ppm Cu,has thepotential of energy generation through pyrolysis and gasification. Thepaper reports its proximate and ultimate analyses, deformation andfusion ash temperatures, lower and higher heatingvalues,physico-chemical and thermal degradation in nitrogen and airatmospheres. The thermal degradation was conducted inathermogravimetric analyzer from room temperature to 900 °C atheatingrates of 20 and 40 K min-1. The thermogravimetric, derivativethermogravimetric and differential thermal analyses were carried out todetermine the rate of volatiles evolution, the effect of heatingrateson the thermal degradation characteristics and to determine theglobal mass loss kinetics of thermal degradation. The thermaldegradation was found to occur in several distinct phases: each phasegiving volatile evolution in an independent parallel lump. Eachdecomposition phase was modeled by a single irreversible reaction withrespect to the solid mass. Global mass loss kinetics was alsodetermined for the entire decomposition process, as if occurring in onesingle step. The integral and differential techniques were used for thedetermination of kinetic parameters. Using the method of Agrawal andSivasubramanian [R.K.Agrawal, M.S. Sivasubramanian, AIChE J. 33 (1987)7] for the total degradation zone, the orders of reaction were found inthe range of1.002.50 in both the atmospheres (i.e. nitrogen and air)and the activation energy in the range of 27.8433.44 and 57.4188.92 kJmol-1in nitrogen and air, respectively.
The pre-exponentialfactor was found in the range of 32.195.1 and 5.10× 104 to 5.46 × 109min-1 in nitrogen and air atmospheres,respectively.