Sichuan professor makes biocoal out of leftovers

Want China Times, Staff Reporter 2014-05-19

A staff member of a restaurant dumps leftovers into a bin. (File photo/CFP)

A scholar from Sichuan University created biocoal from leftover food that can produce more electricity than the coal currently used in electricity plants, reports the Chengdu-based WCC Daily.

Lu Hongyan, professor with the university's college of architecture and environment, came up with the idea to turn a ton of leftovers into 80 to 120 kg of biocoal. His research was reviewed and approved by seven experts from and outside of the province on April 29.

The three pieces of equipment required to produce the biocoal are a hypothermal carbonizer, which Lu spent 300,000 yuan (US$48,000) to import from Germany, a recirculated vacuum pump and an electric drum wind drying oven.

Staff members of Lu's laboratory who demonstrated the process put leftovers into the hypothermal carbonizer, where it was baked between one to four hours. The process turned the waste into a blacken porridge-like substance. Then it was placed into the pump to remove 90% of its water and into the oven until it became something similar to soil. Lu said his research team found 1.5 hours the optimal time to process leftovers in the carbonizer. The soupy result can be left to dry at room temperature if needed.

He said the process can turn 40-60% of a ton of leftovers into burnable biocoal. The remaining leftovers become gas and liquids. The biocoal can produce 6,630 to 7,730 calories of electricity per kilogram, higher than coal used to produce electricity at 4,800 to 5,500 calories.

The liquid can be used to produce biogas or even fertilizer if the leftovers do not contain any hazardous materials.

The professor was inspired by waste recycle in Germany, where he lived for eight years. He has carried out the research for three years and plans to build a factory to process larger amounts of leftovers after approval.