Coffee grounds can also be used to extract biodiesel.

According to foreign media reports, coffee can not only satisfy your hunger as afternoon tea, but also turn it into biofuel and drive your car. This statement comes from a study by scientists at the University of Nevada in the United States, who have found that boiled coffee grounds can also be used to produce biodiesel.

The researchers said in a published article that the technology of making diesel from coffee grounds is not difficult and can be extracted with chemical solvents. According to the U.S. Department of Agriculture, more than 16 billion pounds (0.4536 kilograms) of coffee are produced worldwide each year, and coffee residues contain 11%, 20% of bio-oil. As a result, scientists estimate that coffee residue can provide more than 340 million gallons of biodiesel each year.

Manomisra, a professor of engineering at the University of Nevada, Nalasm Harrokunda Modi and Susan Ta Mohapatra conducted the study. Scientists have known for decades that coffee contains bio-oil, but Misra is the first person to scientifically analyze coffee powder. Misra and her companions believe that the coffee grounds may contain a certain amount of bio-oil. So they went to several Starbucks coffee shops, collected a total of 50 pounds of coffee grounds, dried them in an oven, and then put them in a solvent to extract oil. These solvents can be reused, and the residue can also be used as fertilizer, ethanol raw material and fuel pellets.

The study found that the content of bio-oil in coffee grounds reached about 15%, which was lower than that of soybeans, rapeseed and palm oil. But coffee oil is more stable because it contains more antioxidants. Dr. Misra says the whole process does not take much energy. They estimate that the biodiesel produced in this way can be sold for about $1 a gallon.

However, Dr. Mishra also said that there is a problem with the production of biodiesel from coffee grounds, which is that coffee grounds cannot be collected efficiently, so large-scale production is estimated to be problematic. The researchers plan to set up a small pilot coffee circulation system next year to get coffee grounds from Starbucks and send them to biodiesel processing plants. However, even if the entire world's coffee grounds are used to produce biodiesel, its biodiesel production is less than 1% of the annual diesel consumption in the United States.

"producing diesel from coffee grounds will not replace gasoline to solve the world's energy problem, but hot milk coffee will one day reduce our impact on the environment," Dr. Misra said. Moreover, our goal is to use waste materials and convert them into useful fuel. " Moreover, the biodiesel produced by coffee grounds has another advantage: using coffee grounds to produce fuel, the car exhaust will contain the strong aroma of coffee.