Technically pyrolysis is defined as the thermal degradation of material at a high temperature in the absence of oxygen gas. The resulting byproducts of this degradation are condensate (water/tar) and non-condensable gasses. If the feedstock is biomass, then the byproducts can also include biochar. The proportions for each of these byproducts mainly depend on the feedstock and operating conditions.
Some pyrolyzers are called ‘slow pyrolyzers’ because they break down the feedstock slowly, resulting in carbon, syngas, oxides, and biochar as significant byproducts.
The other type of system is referred to as a fast pyrolyzer, and the resulting outputs can include solids, liquids, and gasses. In biomass applications, the focus is often on bio-oils and biochars as an effective carbon sequestration output.
The primary goal of most pyrolysis technologies is to convert existing feedstocks into higher-value intermediate liquids, which can then be refined and added to a range of products, including hydrocarbon fuels, petrochemicals, and oxygenated fuel additives.