Compatibility of Direct Sugar to Hydrocarbon (DSH-76) with Combined Contaminated Fuel Detector

Testing of the Navy's Combined Contaminated Fuel Detector with alternative sourced fuels was conducted as a part of the ongoing effort to certify the use of renewable fuels in all Navy aircraft and ships. Current certification efforts are focused on F-76 produced from the direct sugar to hydrocarbon (DSH) production process. Petroleum sourced F-76, alternative fuel source DSH-76 and 70/30 & 50/50 blends of F76/DSH76 fuel were contaminated with various levels of synthetic dirt or free water and tested in accordance with current CCFD operating guidelines. The particulate levels for all four samples were found to be measured much lower than the known amount of contaminant added or the results obtained by the ASTM referee gravimetric method. This discrepancy is a known issue with F-76 and the CCFD. To mitigate this issue, a comparison instrument response was plotted for each of particulate contaminants in various fuel types. This analysis showed that CCFD measurements are the same for all four of the fuels tested. The free water measurements were similar for neat DSH-76 and DSH-76 and petroleum F-76 blends within repeatability of the method. Based on the results of this study, use of F-76 produced by the DSH process will not adversely affect the contaminant measurements made by the CCFD. The original document contains color images.