A rapid and accurate method for on-line measurement of straw–coal blends using near infrared spectroscopy

On-line measurement of biomass–coal blends is very important for developing appropriate subsidy policies for biomass co-firing power generation. Near infrared reflectance spectroscopy (NIRS) was used for on-line qualitative analysis of straw, coal and straw–coal blends and on-line quantitative analysis of straw content of straw–coal blends. A total of 80 straw samples, nine coal samples, 120 straw–coal blends samples with straw content from 70% to 99% (blends1) and 120 straw–coal blends samples with straw content from 1% to 30% (blends2) were prepared. Spectra were obtained using a Thermo Fisher Scientific Antaris Target FT-NIR spectrometer. Linear discriminant analysis method was used for qualitative analysis, correct classification percentages of straw, blends1, blends2 and coal were 89.87%, 79.66%, 94.92% and 100%, respectively. The ratio of standard error of performance to standard deviation (RPD) of quantitative analysis model was 3.52. It is concluded NIRS is a rapid and accurate method for on-line measurement of straw–coal blends.