Seasonal chemical variations of South Denmark's organic municipal waste and its estimated bioenergy potential

The paper reports the results of the annual analysis of the composition of the organic fraction of municipal solid waste (OFMSW), considering the seasonal effect. The research showed a direct association between climate characteristics of seasons and the levels of metals, organic acids, and solids. Principal component analysis further revealed the seasonal patterns based on increasing the months' distance from July. The variation of OFMSW composition significantly amplifies, making the variation in OFMSW composition between July and January most distinguishable. Moreover, the division of months into two groups was established, considering the changing OFMSW composition over the year. Partial least squares discriminant analysis was applied to identify variables that contributed the most to the deviation between the two groups. The findings highlight the content of solids, lactic acid, acetic acid, ethanol, sodium, potassium, aluminum, and manganese in OFMSW as the variables demonstrating the most substantial impact on the observed seasonal differences. Moreover, the theoretical biomethane and bioethanol potential were investigated, showing fluctuations of 376–491 mL CH4/g VS OFMSW dry matter and 15.3–22.1 bioethanol g/100 g OFMSW dry matter, respectively.