If waste plastics are to be recycled as a material, the
negative influence of degradation is obvious. The reason
that degradation also affects the quality of pyrolysis oil
lies in the fact that the chemically bound oxygen from the
degraded polymer chains is carried over into to the pyrolysis
oil. As a result, the oil becomes acidic and attacks
the inner walls of combustion engines and fuel pipes. In
addition, chemically bound oxygen reduces the heating
value of the oil (i.e. the amount of heat released during
combustion of a given amount of oil, e.g. 1 kg).