Use of measurement uncertainty analysis to assess accuracy of carbon mass balance closure for a cellulase production process |
| |
Authors: | Schell Daniel J Sáez Juan Carlos Hamilton Jenny Tholudur Arun McMillan James D |
| |
Institution: | (1) National Renewable Energy Laboratory, 1617 Cole Boulevard, 80401 Golden, CO;(2) University of Puerto Rico, Mayagüez Campus, PO Box 9046, 00681 Mayagüez, Puerto Rico;(3) Covance Biotechnology Services, Inc., 3000 Weston Parkway, 27513 Cary, NC |
| |
Abstract: | Closing carbon mass balances is a critical and necessary step for verifying the performance of any conversion process. We
developed a methodology for calculating carbon mass balance closures for a cellulase production process and then applied measurement
uncertainty analysis to calculate 95% confidence limits to assess the accuracy of the results. Cellulase production experiments
were conducted in 7-L fermentors using Trichoderma reesei grown on pure cellulose (Solka-floc), glucose, or lactose. All input and output carbon-containing streams were measured and
carbon dioxide in the exhaust gas was quantified using a mass spectrometer. On Solka-floc, carbon mass balances ranged from
90 to 100% closure for the first 48 h but increased to 101 to 135% closure from 72 h to the end of the cultivation at 168
h. Carbon mass balance closures for soluble sugar substrates ranged from 92 to 127% over the entire course of the cultivations.
The 95% confidence intervals (CIs) for carbon mass balance closure were typically ±11 to 12 percentage points after 48 h of
cultivation. Many of the carbon mass balance results did not bracket 100% closure within the 95% CIs. These results suggest
that measurement problems with the experimental or analytical methods may exist. This work shows that uncertainty analysis
can be a useful diagnostic tool for identifying measurement problems in complex biochemical systems. |
| |
Keywords: | Cellulase carbon mass balance cellulose uncertainty analysis Trichoderma reesei |
本文献已被 SpringerLink 等数据库收录! |
|