Near infrared spectrometric method of acid value in biodiesel methyl esterification production process

Abstract

The invention discloses a near infrared spectrometric method of an acid value in a biodiesel methyl esterification production process. The acid value of a detected sample is indirectly determined by using doubled-frequency absorption and combined frequency absorption of free fatty acid hydric group COO-H in a grease to generate a spectrogram and using a partial least squares regression and optimalfactor number selection principle factor regression method to make an acid value measuring model. The near infrared spectrometric method of the acid value in the biodiesel methyl esterification production process comprises the operation steps of (1) centrifuging a grease methyl esterification process sample in the production 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 wipe a color through surface of the cuvette; (3) according to an original state of an instrument, selecting a pre-made measuring model for reference, placing the cuvette filled with the sample to be detected into a sample cell to be scanned, and calculating the acid value of the sample by using an acid 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 acid value in the biodiesel methyl esterification production process, 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 acid value of biodiesel (fatty acid methyl ester), in particular to a near-infrared spectrum method for measuring the acid value in the methyl esterification production process of biodiesel. Background technique [0002] acid value [1] It is a main product index of biodiesel products. It is the number of milligrams of potassium hydroxide consumed to neutralize free fatty acids in 1 gram of biodiesel. The value represents the degree of methylation of free fatty acids. Biodiesel Blend Fuel (B5) [2] acid value [3] Indicators set clear requirements. [0003] Biodiesel has a wide range of applications in fine chemicals, especially as a raw material for a bio-based environmentally friendly plasticizer (epoxymethyl ester, methyl chloride) that replaces the non-environmental friendly plasticizer DOP. The acid value index has a great influence on the plasticizing performance. The acid value is used as the...

AI Technical Summary

Problems solved by technology

[0004] In the industrial production of oil methyl esterification, the frequency of acid value detection is very high, and the existing detection technology not only has a very heavy detection workload, but also consumes a large amount of chemicals

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