Potential errors in the quantitative evaluation of biogas production in anaerobic digestion processes.
Potential errors in the quantitative evaluation of biogas production in anaerobic digestion processes.
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DOI：
10.1016/j.biortech.2009.07.018
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发表时间：
2009-12
影响因子：
11.4
通讯作者：
M. Walker;Yue Zhang;S. Heaven;C. Banks
中科院分区：
文献类型：
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作者：
M. Walker;Yue Zhang;S. Heaven;C. Banks
对厌氧消化实验中沼气定量中常见的误差进行了研究。对于液体置换式气体流量计，其中阻隔解决方案将沼气和大气分离，实验检查了由于气体扩散引起的不准确性。酸化饱和盐水溶液是最合适的屏障溶液，因为沼气特性随时间变化最小。使用酸化水或自来水会造成相当大的沼气损失，因此应避免在测量前储存沼气。从理论上研究了三种常见的液体置换式气量计容积计算的误差。讨论了在使用该设备时，为获得标准温度和压力下的气体体积而必须进行的校正。关于实验误差，气体计量器的设计是最通用的，因为误差主要取决于平衡灵敏度。使用液体高度来计算体积需要相对于所测量的气体体积适当地确定气体计的尺寸。对低流量燃气表的校准进行了研究，发现其随流量呈近似线性变化;因此建议对此类仪器进行现场校准。大气条件的校正应在真实的时间内进行，以减少误差。
Errors that are commonly made in the quantification of biogas from anaerobic digestion experiments were investigated. For liquid displacement gasometers where a barrier solution separates the biogas and the atmosphere, inaccuracy due to gas diffusion was examined experimentally. Acidified saturated saline solution was the most suitable barrier solution, as biogas characteristics changed least with time. Using acidified or tap water caused considerable biogas losses and should therefore be avoided where biogas is stored before measurement. Errors associated with volume calculation from three common liquid displacement gasometer types were investigated theoretically. Corrections that must be made to obtain gas volumes at standard temperature and pressure when using this equipment are discussed. Regarding experimental errors, gasometer designs where displaced liquid is weighed to determine the volume are the most versatile since errors depend mainly upon balance sensitivity. Using liquid heights to calculate volume requires appropriate sizing of the gasometer relative to the volume of gas measured. The calibration of a low flow gas meter was investigated and an approximately linear variation with flow rate was found; hence in situ calibration is advised for this type of instrument. Correction for atmospheric conditions should be performed in real time to reduce errors.