Due to the coexistence of lignocellulosic materials and syn-thetic polymers in solid wastes in very large quantities, theserequire effective co-management. The pyrolysis, as a non-oxidativethermochemical conversion process, is a simple way of cellu-lose degradation with a formation of various liquid products,mainly monosaccharides, furans and pyrans derivatives [17,18].The fact that polyolefins are rich in high hydrogen (14%) andcarbon contents may raise the interest of obtaining liquid com-pounds (hydrocarbons) characterized with high calorific value. It isassumed that polyolefinic polymers may provide hydrogen duringpyrolytic conversion of biomass and increase the bio-oil production[19