Near infrared spectrometric method of iodine value of biodiesel

Abstract

The invention discloses a near infrared spectrometric method of iodine value of biodiesel. The iodine value of a detected sample is indirectly determined by using doubled-frequency absorption and combined frequency absorption of C=C and hydrogen group C-H vibrations in a grease to generate a spectrogram and using a partial least squares regression and optimal factor number selection principle factor regression method to make an iodine value measuring model. The near infrared spectrometric method of the iodine value of the biodiesel comprises the operation steps of (1) centrifuging a grease sample obtained in production to eliminate an impurity effect so as to prepare a sample to be detected; (2) putting the sample to be detected into a quartz cuvette, and using a lens wiping paper to wipea color through surface of the cuvette; (3) according to an original state of an instrument, selecting a pre-made iodine value measuring model for reference, placing the cuvette filled with the sampleto be detected into a sample cell to be scanned, and calculating the iodine value of the sample by using an iodine value measuring and analyzing model software after near infrared detection; and (4)taking out a test sample in the sample cell and recycling the test sample, washing the cuvette, and dipping the cuvette in absolute ethyl alcohol and drying the cuvette for future use. The near infrared spectrometric method of the iodine value of the biodiesel, disclosed by the invention, has the advantages of simple and fast operation, low cost, high accuracy and good applicability.

Description

technical field [0001] The invention relates to a method for measuring the iodine value in the production process of biodiesel (fatty acid methyl ester), in particular to a method for measuring the iodine value of biodiesel with near-infrared spectroscopy. Background technique [0002] Iodine value is a main product index of biodiesel products, which is the quality of neutralizing iodine absorbed by 100 grams of fatty acid methyl esters. The value represents the degree of unsaturation of fatty acid methyl esters, that is, the number of C=C double bonds. Biodiesel Blend Fuel (B5) [1] There are clear requirements for the iodine value index. [0003] Biodiesel has a wide range of applications in fine chemicals, especially as a bio-based environmentally friendly plasticizer to replace the non-environmentally friendly plasticizer DOP [2] (Methyl epoxy ester, methyl chloride) has attracted much attention, and its iodine value index has a great influence on the plasticizing perfo...

AI Technical Summary

Problems solved by technology

Therefore, in the industrialized production of fatty acid methyl esters, the frequency of iodine value detection is very high, but the detection time of the above-mentioned prior art for the determination of iodine value is long, the detection workload is large, and a large amount of chemicals are consumed, and the detection cost is high

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