PYROLYSIS OF PROTEINS IN THE PRESENCE OF ACTIVE INORGANIC SOLIDS

摘要

Analytical studies on the effect of active solids on the pyrolytic behavior of biomass components havernbeen conducted principally to lignin and cellulose. Proteins have been less investigated, nevertheless they mayrnconstitute an abundant fraction of some biomass feedstock (e.g. algae). Here the pyrolytic behaviour of proteins in thernpresence of CaO and zeolite H-ZSM-5 was investigated by off-line analytical pyrolysis utilising bovine serumrnalbumin (BSA) as model protein. Pyrolysis products evolved at 700 ℃ were analysed by GC-MS and the yields ofrnmain 2,5-diketopiperazines (DKP, cyclic dipeptides) were determined by internal standardisation. Active solids at 1/1rnratio with respect to BSA did not affect markedly the pyrolysate composition which was dominated by thermalrnfragmentation products of the side chain of aromatic amino acids and lower levels of DKPs. At higher ratios (9/1)rnzeolite induced aromatisation and alkylation with the formation of polyaromatic hydrocarbons (PAHs) andrnmethylated phenols and indoles. The formation of DKPs, among which cyclo(Pro-Leu) was the most abundant, wasrnfavoured by catalytic pyrolysis. The yields of DKP increased from about 1‰ from untreated BSA to 5 ‰ in thernpresence of zeolite.