Coalsmith—Coal Utilization Solutions

Bethany Snoby and I have an article in American Coal Councils publication American Coal (issue 2, 2010) on “Valuation of Precombustion Coal Cleaning Facilities for Power Plants” which describes a model for calculating the financial value of tradeoffs between coal prep costs and combustion efficiency improvements. This helps unfamiliar users estimate the amount to spend on coal prep plants to get the improvements in electric plant efficiency and performance, and what level of cleaning to pursue for optimum results. Contact me if you want to see it.

Finishing up the final report of testing for LCRA’s Sabia analyzers. The testing is completed and results are under review.

http://www.energybiz.com/article/10/09/duke-may-ditch-coal

Duke may retire several coal plants over the next 5 years, prefering to mothball them rather than pay carbon tax.

Online coal analysis testing compares the laboratory results from a conventional sampling process, to the analyzer results using PGNAA and the current calibration. The objective is to statistically compare the two readings for ash, sulfur, and btu/lb and determine if the calibration linear equation is confirmed.

There are two types of tests that can be performed. A static test of coal or prepared sample tubes is used to confirm factory calibration after installation. This checks the repeatability of the device and software to initial manufacturers specs.

The next type of test is more dynamic. Coal is flowing on the belt in batches, whose mass matches the desired response time, say 5 or 10 minutes. This mass of coal is then sub-sampled by stopped belt increment or a sweep sampler. The analysis of about 30 batches are compared by the Hotelllings t2 statistic, a multivariate student’s t test. The results should be within 10% relative variance compared to the average of the reference, the conventional coal sample. This shows why accurate coal sampling is a must for good analyzer calibration.