Prof. Jiane Zuo

School of Environment, Tsinghua University



Integrated treatment and utilization of food waste

 - a case in Shandong, China





This study works on the integrated treatment of food waste and other organic wastes to form a complete technology system. Shandong Province was chosen as the demonstration area, in which  three food waste disposal projects in Jinan, Qingdao and Yantai were included, and even the landfill biogas was combined together to build a biogas production-purification-supply integration center. The main results include: The mixing of food waste with wheat straw and corn silage is beneficial to improving the gas production and the operational stability of the system. The hydrolysis degree of kitchen waste can be enhanced by pH regulation and heating pretreatment, and the efficiency of gas production can be improved. The high efficiency extraction of waste oil from kitchen waste is developed by heating pretreatment technology. A process for preparing polylols from food waste and waste oil is developed, and polylols is synthesized from the waste oil to produce high value products. Regional joint projects for multiple gas purification was carried out and the mobile vehicle biogas purification equipment, and small mobile biogas purification equipment were developed for different scale utilization. The pyrolysis test and analysis of light substances in kitchen waste were carried out, and the external thermal and internal thermal pyrolysis system was designed for different conditions. Based on the basic principle of anaerobic digestion, a new double loop nested two-phase efficient anaerobic digestion reactor was developed. Within 4 years, 5 demonstration food waste treatment and biogas purification centers (including one in Kunming and the other in Xiamen) were built and operated, the scale of food waste treatment reached to 1450 t/d while the biogas production was more than 11.22 billion m3/year.