A cost effective alternative to the existing treatment steps of the refining by-ptoducts, is the “on site” energetical valorization through 2 comparable technologies: thermal oxidation and anaerobic digestion combined with boiler. In a thermal multifluid oxidizer Cinclus®, the mixture is injected with atomisation and combustion air at high velocity into the oxidation chamber. The jet creates a local under-pressure and thus an internal recirculation in the oxidation chamber. This results in a controlled and homogeneous temperature and residence profile that ensure an optimal combustion with low emissions. To prevent persistent boiler fouling, the gases are cooled to below 750 °C in the gas conditioning chamber by mixing the hot gases with recycled gases taken from behind the de-dusting device. Divert investment for fossil fuel boiler and soap stock splitting to install Cinclus soap stock boiler will allow: no acid waste water, no interphase, no sulfuric acid consumption, no fossil fuel consumption. The Dranco process is a well-known and reliable anaerobic digestion technology. Its simple digester design, no moving parts within the digester, provides a high reliability and low maintenance costs. The Dranco process parameters are roughly: digester loading: 10 to 20 kg COD/m3 reactor.day. The temperature range of the thermophilic organisms is 50 to 58 °C. The retention time in the digester is about 15 to 30 days. The biogas production is above 300 m3 of biogas per ton of waste. The electricity production: above 500 kWh per ton of waste. The advantages of anaerobic digestion of waste are: The production of renewable energy and reduction of fossil CO2-emissions ; the low odour emissions and in general low emissions towards the environment.