Near infrared spectrometry method for neutral oil in ester exchange production process of biodiesel

Abstract

The invention discloses a near infrared spectrometry method for neutral oil in the ester exchange production process of biodiesel. According to the near infrared spectrometry method, doubled-frequencyand combined-frequency absorption of vibration of glyceride hydric groups C-H and COO-H in grease is utilized to generate a spectrogram, a neutral oil measurement model is produced by partial least-squares regression and optimum-factor-number selection principle factor regression methods, and the neutral oil in a measured sample is indirectly determined. The near infrared spectrometry method comprises the operation steps of: (1) carrying out a centrifugal operation on a grease ester exchange process sample in the production to prepare a to-be-measured sample; (2) filling the to-be-measured sample into a quartz cuvette, and wiping the translucent surface of the cuvette clean with lens wiping paper; (3) selecting the preset neutral oil measurement model to carry out reference according to an original state of an instrument, then placing the cuvette with the to-be-measured sample into a sample pool to carry out spectrum scanning, and after near infrared detection, calculating content ofthe neutral oil in the sample by neutral oil measurement analysis model software; and (4) recovering the test sample after taking the test sample out of the sample pool, washing the cuvette and aftersoaking the cuvette with absolute ethyl alcohol, air-drying for later use. The near infrared spectrometry method is simple, rapid and convenient to operate, low in cost, high in accuracy and high in applicability.

Description

technical field [0001] The invention relates to a method for measuring the neutral oil of biodiesel (fatty acid methyl ester), in particular to a near-infrared spectrum method for measuring the neutral oil in the biodiesel transesterification production process. Background technique [0002] Neutral oil is a main process control index in the transesterification process of biodiesel production. It is the mass fraction of glycoside oil esters that have not completed the transesterification process. It is an index for determining the process of transesterification reaction, and finally affects the product index of biodiesel total glycosides and combined glycerin. Biodiesel Blend Fuel (B5) [1] Put forward clear requirements on the total glycerol index. [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 fr...

AI Technical Summary

Problems solved by technology

At present, there is no corresponding national standard applicable to the field of biodiesel (chromatographic method requires derivatization, and then chromatographic analysis [2] , it takes too long to guide industrialized production), Joyo Group currently adopts atmospheric distillation cracking detection method ("Testing Center - XMZYQD-29(11)-2011-Neutral Oil Analysis Operation Method Regulations") [3] ) has relatively strong production guidance, but the disadvantage is that the entire experiment takes nearly an hour, and there is a certain lag

[0004] In the industrialized production of oil transesterification, the detection frequency of neutral oil is very high, and the workload is very large when the detection is carried out according to the above-mentioned prior art, and a large amount of chemicals are consumed, and cracking gas is generated during the experiment, and the taste is relatively strong. Affects the regional atmospheric environment to a certain extent