Search

KR-102962619-B1 - Method for Conversing from High Acid Value Fatty Acid to Bio Fuel Oil or Biodiesel

KR102962619B1KR 102962619 B1KR102962619 B1KR 102962619B1KR-102962619-B1

Abstract

The present invention relates to a method for efficiently converting lower-grade oils into lower-grade alkyl esters by reducing their acid value. By providing lower-grade alcohols in a liquid state at the bottom of a reactor under an acid catalyst and immediately vaporizing them inside the reactor to maximize the efficiency of the esterification reaction by increasing the mixing and contact area of the reactants, the invention provides an economical method that efficiently lowers the acid value of lower-grade oils while converting them into fatty acid alkyl esters that can be used for biodiesel.

Inventors

  • 임대재
  • 전경수
  • 양영도
  • 김보근
  • 김윤
  • 황지은

Assignees

  • 주식회사이맥솔루션

Dates

Publication Date
20260513
Application Date
20221230

Claims (13)

  1. A step of introducing low-grade oil and an acid catalyst from the top of a batch reactor and raising the temperature of the batch reactor to 90 to 190 ℃ at atmospheric pressure; A step of introducing a C1 to C4 alcohol at the bottom of the above batch-type reactor to esterify the lower oil and reduce the acid value of the lower oil; and A method for producing a fatty acid alkyl ester comprising the step of obtaining a fatty acid alkyl ester from the acid value-reducing lower oil obtained above; A method for producing a fatty acid alkyl ester, wherein in the above esterification reaction step, the water produced and the unreacted C1 to C4 alcohol are separated at the top of the reactor, and the separated unreacted C1 to C4 alcohol is recirculated at the bottom of the reactor.
  2. In paragraph 1, A method for producing a fatty acid alkyl ester, wherein the above C1 to C4 alcohols are immediately vaporized within the reactor.
  3. In paragraph 1, A method for producing a fatty acid alkyl ester, wherein the content of C1 to C4 alcohol introduced into the above reactor is 5 to 60 parts by weight per 100 parts by weight of lower oil.
  4. In paragraph 1, A method for producing a fatty acid alkyl ester, wherein when the acid value of the lower oil is 50 mgKOH/g or less, the content of C1 to C4 alcohol introduced into the reactor is 5 to 30 parts by weight per 100 parts by weight of the lower oil.
  5. In paragraph 1, A method for producing a fatty acid alkyl ester, wherein when the acid value of the lower oil is 150 mgKOH/g or less, the content of C1 to C4 alcohol introduced into the reactor is 40 to 70 parts by weight per 100 parts by weight of the lower oil.
  6. In paragraph 1, A method for producing a fatty acid alkyl ester, wherein when the acid value of the lower oil is 100 mgKOH/g or less, the content of C1 to C4 alcohol introduced into the reactor is 20 to 50 parts by weight per 100 parts by weight of the lower oil.
  7. In paragraph 1, A method for producing a fatty acid alkyl ester, wherein the content of the above acid catalyst is 0.1 to 0.5 parts by weight per 100 parts by weight of lower oil.
  8. In paragraph 1, A method for preparing a fatty acid alkyl ester, wherein the time of the esterification reaction step is 1 to 6 hours.
  9. delete
  10. In paragraph 1, A method for producing a fatty acid alkyl ester, wherein the acid value of the lower oil is 0.1 to 20 mgKOH/g, following an esterification reaction between the lower oil and a C1 to C4 alcohol.
  11. In paragraph 1, A method for producing fatty acid alkyl esters, wherein the ratio of the above lower oil reacting with a C1 to C4 alcohol to be converted into a fatty acid alkyl ester is 95% or more.
  12. In paragraph 1, A method for preparing a fatty acid alkyl ester, wherein the C1 to C4 alcohol is methanol.
  13. In paragraph 1, A method for producing fatty acid alkyl esters, wherein the above acid catalyst is sulfuric acid.

Description

Method for Reducing Acid Value of Low-Grade Oils {Method for Conversing from High Acid Value Fatty Acid to Biofuel Oil or Biodiesel} The present invention relates to a method for efficiently converting low-grade oils into high-quality fatty acid alkyl esters by reducing the acid value of the oils. Non-edible low-grade oils contain not only triglycerides but also free fatty acids, glycerin, monoglycerides, and diglycerides resulting from their breakdown; since the content of free fatty acids is the highest among these, the acid value is very high. The acid value of an oil refers to the number of milligrams of KOH required to neutralize the free fatty acids contained in 1 gram of oil. Low-grade oils with such high acid values can be used as a raw material for biodiesel by lowering the acid value or converting them into fatty acids through esterification reactions, mainly under acid or base catalysts. Biodiesel is an eco-friendly fuel produced by converting triglycerides, the main components of vegetable oils or animal fats, into alkyl esters through transesterification with alcohol. Its cetane number, calorific value, viscosity, and phase transition characteristics are very similar to those of diesel fuel refined from petroleum, and due to its unique lubricating properties, it is used as an additive or substitute for conventional diesel fuel. Currently, most biodiesel is produced using vegetable oils (rapeseed oil, soybean oil, palm oil, waste oil, etc.) as raw materials. Not only is the proportion of raw material costs in total production high, but there are also problems with the supply of raw materials being unstable due to the demand for vegetable oils in the food market. To address these issues of raw material supply instability and high costs, active process development is underway to utilize low-grade oils with high acid values, such as waste oil or palm oil byproducts (palm fatty acid distillate, PFAD; palm acid oil, PAO), which are difficult to use for food, as raw materials for biodiesel production. Accordingly, methods for converting low-grade oils into biodiesel are being developed, but most of these conversion methods use an excess amount of methanol for reaction efficiency, which is not only uneconomical but also has the problem of showing a low conversion rate relative to the reaction time. Therefore, there is a need for a method to convert low-grade oils into biodiesel that is economical and exhibits a high conversion rate. Figure 1 shows a process diagram of a method for reducing the acid value of low-grade oil according to the present invention. The present invention is described below in detail so that those skilled in the art can easily implement it. However, the present invention may be embodied in various different forms and is not limited to the embodiments described herein. Furthermore, it is not intended to limit the scope of protection defined by the claims. Furthermore, unless otherwise defined, technical and scientific terms used in the description of the present invention have the meaning commonly understood by those skilled in the art to which this invention pertains, and descriptions of known functions and configurations that could unnecessarily obscure the essence of the present invention are omitted in the following description. The numerical ranges used in this specification include lower and upper limits and all values within the range, increments logically derived from the form and width of the defined range, all of which are limited values, and all possible combinations of upper and lower limits of the numerical range defined in different forms. Unless otherwise specifically defined in the specification of this invention, values outside the numerical range that may occur due to experimental error or rounding of values are also included in the defined numerical range. Unless otherwise specifically defined in the present invention, the phrase “comprising” a certain component means that, unless specifically stated otherwise, it does not exclude other components but may include additional components. Furthermore, the singular form used in the specification and appended claims may be intended to include the plural form unless specifically indicated otherwise in the context. Units used herein without special notation are based on weight, for example, units of % or ratio mean weight % or weight ratio, and weight % means the weight percentage of any one component of the total composition that occupies the composition, unless otherwise defined. The term "substantially not in use" in this specification means that other elements, materials, or processes not listed together with the specified elements, materials, or processes may be present in an amount that does not have an unacceptably significant effect on at least one basic and novel technical concept of the invention. The present invention provides a method for reducing the acid value of a low-grade oil, comprising the steps of: