Depolymerisation of oligolactic acid: Simulation and pilot plant trial

The oligolactic acid thermodestruction process was studied using the pilot plant. The process was described by the system of differential rate equations. The model satisfactorily simulating the pyrolysis of oligolactic acid was built and reactions rate constants were determined. It was shown that to obtain a high purity product higher molecular weight feedstock should be used. That will result in a longer process times. The main impurities are low molecular weight homologues with polymerisation degree 1–3. No significant changes in a molecular mass and molecular mass distribution occur during the pyrolysis. The only changes that have place occur at the initial steps and are due to stripping of light components and, possibly, depolymerisation. When the oligomer molecular mass Mn reaches a certain threshold value no further changes occur. Pilot plant trials showed the good agreement of simulation and experiment.