EPSA: FERC Briefing Confirms Importance of Both Existing, New Generation to Reliability
June 26, 2008 // Published as a news service by IHS
The new apparatus for measuring distillation properties produces significantly detailed and accurate data needed to better understand each fuel and its sample-to-sample variation. According to researchers, the data are valuable in tailoring fuels for high performance and low emissions, and in designing new fuels, engines and emission controls.
With few exceptions, petroleum-based fuels are highly complex mixtures of hundreds of distinct components ranging from light butanes to increasingly heavy oils. For decades, distillation curves have provided a widely accepted means of characterizing a fuel. The curve charts the percentage of the total mixture that evaporates as the temperature of a sample is slowly heated. The curve holds a wealth of information - not just the basic makeup of the fuel, but also indicators as to how it will perform. Engine-starting ability, fuel system icing, vapor lock, fuel injection scheduling, fuel auto-ignition, hot- and cold-weather performance and exhaust emissions have all been correlated with features of the distillation curve. The data are important both for quality control at refineries and the design of specialty high-performance fuels.
For all its utility, there are serious problems with the common method for measuring a distillation curve in industry, based on an old ASTM D-86 standard. The method is subject to large uncertainties and systematic errors that make it difficult and/or impossible to relate the test results to thermodynamic theory used in developing modern fuels and engines.
NIST researchers added an additional temperature sensor and made other modifications, decreasing the random uncertainty in the temperature measurement and control from a few degrees to 0.05 degree and eliminating a number of systematic errors. They also added the capability to do a composition analysis of each boiling "fraction," which can provide vital insights into fuel behavior and pinpoint batch-to-batch differences to help diagnose production problems.
Details of the new fuel distillation apparatus and methodology are in two papers:
- T.J. Bruno. Improvements in the measurement of distillation curves. A composition-explicit approach. Industrial & Engineering Chemistry Research, 45(12), pp 4371-4380. http://pubs.acs.org/cgi-bin/abstract.cgi/iecred/asap/abs/ie051393j.html, May 10, 2006.
- T.J. Bruno and B.L. Smith. Improvements in the measurement of distillation curves. Application to aerospace/aviation fuels RP-1 and S-8. Industrial & Engineering Chemistry Research, 45(12) pp 4381-4388. http://pubs.acs.org/cgi-bin/abstract.cgi/iecred/asap/abs/ie051394b.html, May 10, 2006.
"[This] sobering briefing was informative and should instruct critical decisions by federal and state policymakers.
"The country will need substantial investment in new power generation, along with demand response and efficiency measures, to reliably meet increased demand while achieving key environmental objectives.
"The rising infrastructure costs documented by [this] FERC briefing firmly underscore the fundamental importance of maintaining and increasing capacity from existing power plants, as well as building new capacity.
"The economic realities discussed...make it imperative to allow the Reliability Pricing Model in Pjm [Interconnection] and the Forward Capacity Market in New England to function as intended.
"Doing so will give owners of both existing and new generation the reason and the means to make expensive investments to get the most out of existing assets and support building new ones.
"A competitive wholesale marketplace that properly values capacity from all power generation sources in light of global economic realities will bring about the best mix of electricity for consumers in the most efficient and cost-effective manner achievable under these challenging cost conditions."
Source: Electric Power Supply Association (EPSA).