Effect of harvesting time on biomass and combustion quality of Miscanthus lutarioriparius in Dongting lake area

Abstract

Biomass energy, recognized for its potential to supplant traditional energy sources, finds a promising alternative in Miscanthus. Particularly, M. lutarioriparius, a species within the Miscanthus genus, stands out as the most suitable for application. This study focuses on the impact of harvest timing on the biomass and combustion quality of M. lutarioriparius in the coastal wetlands of Dongting Lake, Hunan. A comprehensive field experiment was conducted in this area. The findings reveal several key trends: Firstly, the biomass yield of M. lutarioriparius decreased from 18.42 tons per hectare to 11.25 tons per hectare with the delayed harvest. there is a notable increase in the stem-to-leaf ratio of M. lutarioriparius, primarily attributed to leaf shedding. Secondly, the water content had dropped to 22.33% by the time of harvest in February of the following year. Ash content decreased from 4.55% to 2.17% from October to February of the following year. The calorific value, cellulose and lignin content increased with delayed harvest, while hemicellulose content decreased. Notably, the calorific value exhibits a significant positive correlation with cellulose and lignin content, and a markedly negative correlation with hemicellulose. Thirdly, most mineral elements in the plant demonstrate a significant decrease with delayed harvesting, except for potassium (K) and calcium (Ca), which initially increase and then decrease. The ash content shows a positive correlation with the contents of potassium (K) and silicon (Si). Despite a reduction in biomass yield due to delayed harvesting, combustion quality significantly improves. Therefore, it is concluded that optimal fuel quality is achieved when M. lutarioriparius is harvested in February of the following year.

Keywords

• biomass yield
• harvesting time
• M. lutarioriparius
• quality