Rapid analysis method of crude biodiesel methanol content

Abstract

The invention discloses a rapid analysis method of crude biodiesel methanol content. The content of methanol in crude biodiesel is detected by using a near infrared spectrum analyzer; a spectrogram isgenerated by utilizing frequency multiplication and frequency combination absorption of methyl C-H and hydroxyl O-H vibration in grease, a methanol content measurement model is manufactured by adopting a partial least squares regression and optimal factor number selection principle factor regression method, and the methanol content of a measured sample is indirectly determined. The method particularly comprises the following operation steps: firstly, removing impurities by using a centrifugal machine to prepare a sample to be detected, then putting the sample to be detected into a quartz cuvette, and wiping the color transmitting surface of the cuvette; then selecting the established measurement model for reference, putting the cuvette filled with a sample to be measured into a sample pool for spectrum scanning, setting the sample measurement temperature of the sample pool to be 40 DEG C, and automatically calculating the methanol content of a crude biodiesel sample by a computer after near-infrared detection. The method is simple and rapid to operate, low in cost, good in applicability, free of environmental pollution and high in measurement result accuracy.

Description

technical field [0001] The invention relates to an analysis method for materials in the production process of biodiesel, in particular to a rapid analysis method for methanol content in crude biodiesel. Background technique [0002] The production of biodiesel (fatty acid methyl ester) uses oil or waste oil as the main raw material, and produces biodiesel and glycerin through transesterification with methanol, or produces biodiesel, water and glycerin through esterification and transesterification with methanol, and then produces biodiesel, water and glycerin after the reaction Glycerin and water are separated from biodiesel by standing or centrifuging, and finally biodiesel product is obtained. Since the method of excess methanol is commonly used in the production of biodiesel to increase the conversion rate and reaction speed of biodiesel, the crude biodiesel produced after the reaction contains excess methanol, which needs to be dealcoholized to recycle methanol and reduc...

AI Technical Summary

Problems solved by technology

But above-mentioned existing methanol detection technology has following defect: the one, the detection time of measuring methanol content is long, takes about 1 hour, there is hysteresis, can not meet the requirement of guiding industrialized production; The 2nd, methanol gas is produced in the experimental process , to a certain extent affect the regional atmospheric environment

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