In addition to the basic technology of the biofuel industry, the raw materials used directly determine the environmental protection of the finished biofuel. For example, biodiesel is a very mature industry in Europe, America and Southeast Asia, but at present it is mainly based on a generation of grain crop oil, such as; Palm oil, soybean oil, rapeseed oil and so on are all in line with the international futures market. There is a lot of controversy here. Many people think that using grain as raw material to produce energy has increased the price of international grain supply in disguise, including deforestation and indirect change of land use. Therefore, from the very beginning, the bio-jet fuel industry was determined to use the second-generation raw materials that are more environmentally friendly, including waste and some non-food crops.
Generally speaking, most fuels are hydrocarbons at present. So in theory, many organic substances on the earth can be refined into aviation fuel. If the raw materials are relatively pure (waste oil is mainly hydrocarbons and oxygen), then relatively pure hydrocarbons can be obtained through catalytic deoxidation and hydrodeoxygenation.
But the cost is not low, and there is no stable and sufficient supply of raw materials. In the Netherlands, restaurants and food stores have standardized recycling systems. Generally, the remaining cooking oil will be collected and recycled, but the cooking oil at home is often dumped into the trash can or washed into the toilet and never recycled. SkyNRG, a subsidiary of KLM, found that waste oil can be a good biofuel raw material if handled properly. They deoxidized the vegetable oil first, and then carried out a series of organic chemical processes, so that these waste oils were thoroughly remoulded and became the "renewable flight fuel" they needed.