Biomass yield and biofuel quality of switchgrass harvested in fall or spring
Biomass yield and biofuel quality of switchgrass harvested in fall or spring
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DOI：
10.2134/agronj2005.0351
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发表时间：
2006-11-01
期刊：
影响因子：
2.1
通讯作者：
Jung, Hans-Joachim G.
中科院分区：
文献类型：
--
作者：
Adler, Paul R.;Sanderson, Matt A.;Jung, Hans-Joachim G.
柳枝稷（Panicum virgatum L.）收获影响产量和生物燃料质量，平衡这两个组成部分可能因转化系统而异。一项实地研究比较了秋季和春季收获，测量生物质产量、元素浓度、碳水化合物特性和总合成气产量，作为直接燃烧、乙醇生产和气化系统产生能量的生物燃料质量指标。柳枝稷产量下降了近40%（从约7-4.4兆公顷（-1）），在冬季高于平均降雪量时，收获推迟到春季。水分浓度也有所下降（从约35070 g kg（-1）），仅达到足够低的水平，安全存储的春天。约10%的产量减少，在冬季分蘖质量的减少，但是，几乎90%的产量减少是由于生物量的增加留下的压捆机。矿物元素的浓度普遍下降，直到春天收获的延迟。从气化的能源产量并没有减少单位生物量的基础上，而乙醇生产是可变的，这取决于评估方法。当以单位面积表示时，能量产量下降。生物燃料转化系统可以决定收获时间。对于直接燃烧，春季收获的生物质中降低的矿物质浓度是理想的。然而，对于乙醇发酵和气化系统，木质纤维素产量可能更重要。在保护区的土地上，柳枝稷在冬季提供的野生动物覆盖物可能会增加春季收获的愿望，沿着更高的生物燃料质量。
Seasonal time of switchgrass (Panicum virgatum L.) harvest affects yield and biofuel quality and balancing these two components may vary depending on conversion system. A field study compared fall and spring harvest measuring biomass yield, element concentration, carbohydrate characterization, and total synthetic gas production as indicators of biofuel quality for direct combustion, ethanol production, and gasification systems for generation of energy. Switchgrass yields decreased almost 40% (from about 7-4.4 Mg ha(-1)) in winters with above average snowfall when harvest was delayed over winter until spring. The moisture concentration also decreased (from about 35070 g kg(-1)) only reaching low enough levels for safe storage by spring. About 10% of the yield reduction during winter resulted from decreases in tiller mass; however, almost 90% of the yield reduction was due to an increase in biomass left behind by the baler. Mineral element concentrations generally decreased with the delay in harvest until spring. Energy yield from gasification did not decrease on a unit biomass basis, whereas ethanol production was variable depending on the assessment method. When expressed on a unit area basis, energy yield decreased. Biofuel conversion systems may determine harvest timing. For direct combustion, the reduced mineral concentrations in spring-harvested biomass are desirable. For ethanol fermentation and gasification systems, however, lignocellulose yield may be more important. On conservations lands, the wildlife cover provided by switchgrass over the winter may increase the desirability of spring harvest along with the higher biofuel quality.