Carbon Clean’s pyrolysis process works by taking a waste material and feeding it through an indirect fired rotary kiln. Heat, in the absence or near absence of oxygen, is applied to the material. In the many common applications, the material is then baked and agitated for a period of time until it has been separated into syngas, oil and carbon rich solids. The output is clean fuel (which can be used to fuel the process itself) and carbon based materials such as biochar which acts as a carbon sink and fertility catalyst when added to soil. There are several other applications for pyrolysis where the outputs differ from the explanation above.
Our pyrolysis process has one major piece of equipment and a number of ancillaries that each have industrial precedent. Indirect fired rotary kilns, which are at the core of our process, have been used in large-scale industries for decades. We have worked with and identified the best rotary kiln technology available and added our own improvements and upgrades. This is how we can create low risk, high throughput, scaleable processes with accurate opex and profitability estimations.
The process starts when material is fed into our indirect fired rotary kiln via a series of materials handling equipment, hoppers, feedscrews and sometimes through a dedicated materials drying unit. Once inside the kiln, material moves along a heated, rotating tube with internal lifters for a predetermined period of time at a consistent target temperature (600degC for example). The application of heat and gentle agitation, in the absence of oxygen, breaks the feedstock down into its constituent components. Typically but not always these components consist of: carbon rich solids, syngas and oils.
The solids are discharged from the kiln and cooled via a cooling screw. They are then collected and sent for further sorting/packing/storage etc. When the primary feedstock is biomass based, pyrolysis produces carbon dense material (known as biochar) from the sugars created by the plants during photosynthesis. Biochar represents the carbon present in biomass feedstock that would otherwise have decomposed and escaped into the atmosphere. Biochar amendment in soil is now recognised as one of the most effective means of capturing atmospheric C02.
In the final step, energy rich syngas is directed through a gas cleaning system. The cleaned syngas can be redirected to specialised burners on the pyrolysis unit, making the system self-fuelling and significantly reducing OPEX. Alternatively it can be collected and used as a clean fuel for other processes.
Global demand for circular processes is increasing, driven by increased environmental awareness and the demand for cleaner air, greener energy, clean water and soils, lower emissions and the elimination of waste. As demand for a clean, decarbonised future increases the use of pyrolysis technology will become increasingly important. Carbon Clean’s pyrolysis process is defined by a number of key features and benefits.