Techniques, systems, apparatus and material are described for generating renewable energy from biomass waste while sequestering carbon. In one aspect, a method performed by a reactor to dissociate raw biomass waste into a renewable source energy or a carbon byproduct or both includes receiving the raw biomass waste that includes carbon, hydrogen and oxygen to be dissociated under an anaerobic reaction. Waste heat is recovered from an external heat source to heat the received raw biomass waste. The heated raw biomass waste is dissociated to produce the renewable fuel, carbon byproduct or both. The dissociating includes compacting the heated raw biomass waste, generating heat from an internal heat source, and applying the generated heat to the compacted biomass waste under pressure.