Templeton David W, Wolfrum Edward J, Yen James H, Sharpless Katherine E
National Bioenergy Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, MS 3512, Golden, CO 80401-3305, USA.
Statistical Engineering Division, National Institute of Standards and Technology, 100 Bureau Drive, Stop 8980, Gaithersburg, MD 20899-8980, USA.
Bioenergy Res. 2016 Mar;9(1):303-314. doi: 10.1007/s12155-015-9675-1. Epub 2015 Oct 29.
Biomass compositional methods are used to compare different lignocellulosic feedstocks, to measure component balances around unit operations and to determine process yields and therefore the economic viability of biomass-to-biofuel processes. Four biomass reference materials (RMs NIST 8491-8494) were prepared and characterized, via an interlaboratory comparison exercise in the early 1990s to evaluate biomass summative compositional methods, analysts, and laboratories. Having common, uniform, and stable biomass reference materials gives the opportunity to assess compositional data compared to other analysts, to other labs, and to a known compositional value. The expiration date for the original characterization of these RMs was reached and an effort to assess their stability and recharacterize the reference values for the remaining material using more current methods of analysis was initiated. We sent samples of the four biomass RMs to 11 academic, industrial, and government laboratories, familiar with sulfuric acid compositional methods, for recharacterization of the component reference values. In this work, we have used an expanded suite of analytical methods that are more appropriate for herbaceous feedstocks, to recharacterize the RMs' compositions. We report the median values and the expanded uncertainty values for the four RMs on a dry-mass, whole-biomass basis. The original characterization data has been recalculated using median statistics to facilitate comparisons with this data. We found improved total component closures for three out of the four RMs compared to the original characterization, and the total component closures were near 100 %, which suggests that most components were accurately measured and little double counting occurred. The major components were not statistically different in the recharacterization which suggests that the biomass materials are stable during storage and that additional components, not seen in the original characterization, were quantified here.
生物质成分分析方法用于比较不同的木质纤维素原料，测量单元操作周围的成分平衡，并确定工艺产率，从而确定生物质转化为生物燃料工艺的经济可行性。20世纪90年代初，通过一项实验室间比对实验，制备并表征了四种生物质标准物质（NIST 8491 - 8494标准物质），以评估生物质总量成分分析方法、分析人员和实验室。拥有通用、统一且稳定的生物质标准物质，使得我们有机会将成分数据与其他分析人员、其他实验室以及已知的成分值进行比较。这些标准物质的原始表征有效期已到，因此启动了一项评估其稳定性的工作，并使用更新的分析方法重新确定剩余物质的参考值。我们将四种生物质标准物质的样品送往11个熟悉硫酸成分分析方法的学术、工业和政府实验室，以重新确定成分参考值。在这项工作中，我们使用了一套更适用于草本原料的扩展分析方法，来重新表征标准物质的成分。我们报告了四种标准物质在干质量、全生物质基础上的中位数值和扩展不确定度值。已使用中位统计量重新计算原始表征数据，以便于与这些数据进行比较。我们发现，与原始表征相比，四种标准物质中有三种的总成分闭合度有所提高，且总成分闭合度接近100%，这表明大多数成分被准确测量，几乎没有重复计算的情况。重新表征时主要成分在统计学上没有差异，这表明生物质材料在储存过程中是稳定的，并且在此处对原始表征中未出现的其他成分进行了定量。
