The process of chemical pulping could not be achieved on a large scale without effective chemical recycling. Due to the low yield, there is a large amount of organic matter produced in the digester.
The best way to utilise this organic material is to burn it in a recovery boiler. A pulp mill is then self-sufficient in energy and can often sell energy normally in the form of electricity to the power grid. This recovery and power process consists of evaporation, recovery boiler and white liquor preparation.