几种高大禾草热值和灰分动态变化研究

对3种C₃类植物(芦竹、菅、芦苇)与5种C₄类植物(五节芒、芒、岗柴、斑茅、南荻)不同器官热值和灰分含量的月变化进行了研究,并探讨了其应用前景,为禾草类能源植物筛选评价提供科学依据。结果表明,1)8种高大禾草灰分含量存在差异,且具明显的季节性变化;C₃类植物平均灰分含量分别为:芦竹(7.17±1.09)%、菅(6.33±0.60)%、芦苇(7.89±1.09)%;C₄类植物平均灰分含量分别为:五节芒(4.92±1.38)%、芒(6.27±0.94)%、岗柴(6.99±1.13)%、斑茅(5.13±0.88)%、南荻(5.10±0.82)%。2)C₃类植物中芦竹干重热值较高,C₄类植物中五节芒、芒、斑茅、南荻的干重热值比较接近,无显著差异,岗柴干重热值最低。3)芦竹的干重热值与灰分含量有显著线性相关(P＜0.05),五节芒、芦苇的干重热值与灰分含量有极显著线性相关(P＜0.01),而菅、芒、岗柴、斑茅、南荻的干重热值与灰分含量无相关性(P＞0.05)。4)C₃类植物平均去灰分热值分别为:芦竹(19.01±0.27)kJ/g、菅(18.58±0.31)kJ/g、芦苇(18.72±0.23)kJ/g;C₄类植物平均去灰分热值分别为:五节芒(18.52±0.32)kJ/g、芒(18.69±0.47)kJ/g、岗柴(18.54±0.33)kJ/g、斑茅(18.48±0.41)kJ/g、南荻(18.49±0.37)kJ/g,灰分含量不同,导致去灰分热值与干重热值的月变化趋势不同。

A study on the dynamic change of gross caloric value and ash content of the several tall grasses

Monthly changes in the calorific values and ash contents of 8 tall grasses (three C_3 photosynthetic species (Arundo donax, Themeda villosa, Phragmites communis), five C_4 photosynthetic species (Miscanthus floridulus, M. sinensis, M. sacchariflorus, Saccharum arundinaceum, M. lutarioripara) are discussed in this paper to explore the prospects for applying a scientific basis to develop a screening evaluation for energy plants of these tall grasses. 1) The ash contents of the 8 tall grasses differed and varied with season; the annual average ash contents of the three C_3 photosynthesis species were 7.17±1.09% for A. donax, 6.33±0.60% for T. villosa, and 7.89±1.09% for P. communis; while those of the five C_4 photosynthesis species were 4.92±1.38% for M. floridulus, 6.27±0.94% for M. sinensis, 6.99±1.13% for M. sacchariflorus, 5.13±0.88% for S. arundinaceum, and 5.10±0.82% for T. lutarioripara. 2) Among the three C_3 photosynthesis species A. donax had the highest calorific values, while among the five C_4 photosynthesis species the calorific values of M. floridulus, M. sinensis, S. arundinaceum ,M. lutarioripara were closer to each other with no significant difference. M. sacchariflorus had the lowest calorific values. 3) Gross calorific values were correlated with ash contents for A. donax(P＜0.05), they were strongly correlated for M. floridulus and P. communis(P＜0.01), whereas there was no significant correlation between gross calorific values and ash contents for the other species. 4) The average ash free caloric values of the C_3 photosynthetic species were (19.01±0.27) kJ/g for A. donax, (18.58±0.31) kJ/g for T. villosa, (18.72±0.23) kJ/g for P. communis; and those of the C_4 photosynthesis species were (18.52±0.32) kJ/g for M. floridulus, (18.69±0.47) kJ/g for M. sinensis,(18.54±0.33) kJ/g for M. sacchariflorus, (18.48±0.41) kJ/g for S. arundinaceum, (18.49±0.37) kJ/g for M. lutarioripara. The seasonal changes in ash free caloric values were different from those of the gross caloric values due to differing ash contents in the 8 tall grasses.