Iam a lecturer and also a PhD student. The hypothesis of my thesis is that delignification in biorefinery pulping of papyrus using a mixture of organic acids (50% formic acid, 30% acetic acid and 20% water v/v)is not a chemical reaction-controlled reaction but that it is a mass transfer-controlled reaction and that the shrinking core model applies. The assumption is that the rate of reaction is an intensive property for a constant concentration of liquid reagents in such a heterogeneous reaction system. What do you guys think? I need your help. What kind of rate-measuring instruments could be used to prove or disprove the hypothesis? Could the % pulp yield, % hemicellulose yield and % lignin yield serve as parameters to check this hypothesis? Thank you.