Many experts believe that hydrogenation can be used to treat mixed plastic products. When mixed plastic fragments are placed in the hydrogen reactor at a specific temperature and pressure, raw materials such as synthetic crude oil and gas can be produced. This treatment method can be used to treat PVC waste. Its advantage is that it does not produce toxic dioxins and chlorine gas. This method can be used to treat mixed plastic products. According to different plastic components, 60%-80% of them can be converted into synthetic crude oil. In a joint research report, three national chemical companies, such as Basf, Germany, pointed out that hydrogenation is the best way of pyrolysis, and the synthetic crude oil produced by precipitation is of good quality and can be used for refining.
The University of Kentucky in Lexington has invented a process of plastic recycling, which converts waste plastics into high-quality plastic fuel oil. The fuel produced in this way is very similar to crude oil, even lighter than crude oil, and it is easier to refine into high octane number fuel oil. The fuel oil produced from waste plastic recycling contains no sulphur and very few impurities. A similar method is used to liquefy plastics with coal. It can also produce high quality fuel oil.
Researchers mix plastics with zeolite catalysts and tetrahydronaphthalene in baths, and then put them into a reactor called a "pipe bomb". Hydrogen is pressurized and heated to decompose macromolecule plastics into compounds with smaller molecular weight. This process is similar to the combination in crude oil treatment. The oil yield of waste plastics after treatment is very high, and the oil yield of polyethylene plastic bottles can reach 88%. When waste plastics and coal are mixed and liquefied in a ratio of roughly 1:1, better fuel oil can be obtained. After evaluating the economic benefits of this process, it is predicted that the fuel oil produced by waste plastics will be transformed into blast furnace in 5-10 years. At present, Germany has begun to build waste plastic recycling equipment with a promising capacity of 200 tons of plastic fuel per day in Botep.