If syngas is the key to packaging sustainability, why haven’t you heard of it? Why isn’t syngas part of your company’s sustainability strategy? Syngas may offer the closest thing to the perfect path for robust, truly circular, chemical recycling. What is syngas? Syngas is primarily a mixture of carbon monoxide and hydrogen, the reactive building blocks of virtually all plastic packaging materials. More importantly, syngas can be readily made from unsorted mixtures of plastic packaging waste using the well-established process of gasification. Pyrolysis is a thermal cousin to gasification, which also produces some syngas, but in lesser quantities, as pyrolysis favors production of char (e.g., charcoal is made by pyrolyzing wood) and a liquid hydrocarbon stew known as pyrolysis oil. Gasification primarily produces syngas.
During World War II, as Germany struggled to maintain petroleum supplies, it turned to coal gasification to produce syngas, from which liquid hydrocarbon fuels were made to support the war effort. Comparing the constituents of coal to packaging plastics (e.g., PET, polyethylene, polypropylene, polystyrene, polyamide, etc.), we find mostly the same elements, namely carbon, hydrogen, oxygen, and nitrogen. It is no surprise that gasification of coal and waste plastics (and paper and virtually all organic chemicals and materials) leads to the same valuable product: syngas. As shown in Figure 1, syngas is used commercially to make much more than hydrocarbon fuels.
