Agricultural and livestock sector's residues in Greece & China: Comparative qualitative and quantitative characterization for assessing their potential for biogas production

• Published in: Renewable & sustainable energy reviews 2022-02, Vol.154, p.111821, Article 111821
• Main Authors: Aravani, Vasiliki P., Sun, Hangyu, Yang, Ziyi, Liu, Guangqing, Wang, Wen, Anagnostopoulos, George, Syriopoulos, George, Charisiou, Nikolaos D., Goula, Maria A., Kornaros, Michael, Papadakis, Vagelis G.
• Format: Article
• Language: English
• Subjects: Agricultural residues; Agro-industrial residues; Anaerobic digestion; Biogas; Biomass; Energy; Livestock wastes
• ISSN: 1364-0321; 1879-0690
• DOI: 10.1016/j.rser.2021.111821

Greece and China are two agricultural countries in which a significant percentage of their biomass consists of agricultural and livestock wastes. In Greece, the management practice that is still applied is burning the majority of the agricultural residues in the field, while in China large amount of untreated agricultural waste causes serious adverse effects on the rural living environment. Residual biomass could arise from the agricultural sector in the form of crop residues and of animal wastes. A comprehensive literature review was performed for both countries on primary agricultural and livestock wastes that includes: (a) crop residues that are left in the fields, (b) animal manures and (c) secondary agricultural wastes consisted of liquid and solid wastes from agricultural products processing plants. The average annual quantity of agricultural residues, animal manure and agro-industrial residues in Greece and China (a small and a large country, respectively) is 10 Mt/y and 860 Mt/y, 26 Mt/y and 216.5 Mt/y, 13.2 Mt/y and 213.7 Mt/y, for each corresponding category. According to the amount of the above residues generated per country, the theoretical estimated energy can reach up to 77 TWh and 5500 TWh for Greece and China, respectively, which suggests that both countries can cover a significant part of their energy needs (approximately 135% and 99%, respectively) only from their agricultural and livestock wastes. Τhese observations constitute strong recommendations mainly addressed to policy makers to substantially strengthen the efforts of research, technological and economic optimization of the applications of energy use of agricultural residual biomass for the benefit of the environment and humanity. •There is a lack in literature regarding the detailed recording of the total quantities of residual agricultural biomass.•A review was performed for Greece and China on (a) crop residues, (b) animal manures and (c) agro-industrial wastes.•It was found that Greece and China can cover their energy needs only from their agricultural and livestock wastes.•The results can provide a sound basis to meet energy needs not only in the countries concerned but also worldwide.