EP2065460A1 - Biological fuel and method for its production - Google Patents

Abstract

Biofuel comprises monoglycerides (5-20 wt.%), diglycerides (30-40 wt.%) and triglycerides (45-60 wt.%), where the biofuel is obtained by esterification of palm oil fatty acid containing educts with glycerin; and exhibits a calorific value of at least 35000 J/g and free fatty acids content of = 2 wt.%.

Description

The present invention relates to a biological fuel and method for its production.

Vegetable oils have found increased use in recent years as fuels and heating fuels, for example for the operation of combined heat and power plants. The most common oils for this purpose are palm oil, rapeseed oil and soybean oil. In terms of global production, soybean oil and palm oil are at the top.

Palm oil is the oil that is extracted from the pulp of the oil palm. Palm kernel oil is extracted separately from the palm kernel. Main production sites for palm oil are Malaysia and Indonesia.

Vegetable oils require refining before use. Here, the vegetable oil is divided into different fractions, which are suitable for different purposes. Refining palm oil produces an inferior fraction known as "palm fatty acid distillate" (PFAD), which consists largely of free fatty acids. Such free fatty acids have a corrosive effect on machine parts. Corresponding materials can therefore practically not be sensibly used as fuel.

It has already been attempted to obtain neutral fats by esterification of fatty acids.

DE 10 2006 019 763 A1 describes, for example, a method for reacting acid fats and oils with polyhydric alcohols. The aim of this document is a substantially complete implementation, for example with the polyhydric alcohol glycerol, as this high calorific values are achieved.

Although the most complete possible formation of triglycerides is advantageous from the point of view of the calorific value. Surprisingly, it has become however, it has been shown that the products thus obtained cause problems in use as a fuel.

The object of the present invention was therefore to provide a fuel which avoids the disadvantages of the prior art.

• einen Brennwert von mindestens 35.000 Joule/g,
• einen Gehalt an freien Fettsäuren (FFA) ≤ 2 Gew.-% und
• eine Zusammensetzung von
  • 5 bis 20 Gew.-% Monoglyceriden,
  • 30 bis 40 Gew.-% Diglyceriden und
  • 45 bis 60 Gew.-% Triglyceriden.

The object is achieved by a fuel obtainable by esterification of palm oil fatty acid-containing educts with glycerol, wherein the product is characterized by

• a calorific value of at least 35,000 joules / g,
• a content of free fatty acids (FFA) ≤ 2 wt .-% and
• a composition of
  • From 5 to 20% by weight of monoglycerides,
  • 30 to 40 wt .-% diglycerides and
  • 45 to 60 wt .-% triglycerides.

According to the invention, therefore, a palm oil fatty acid-containing educt, in particular PATH, is reacted with glycerol, whereby not a complete conversion to triglycerides is desired, but the aim is to obtain a mixture of mono-, di- and triglycerides.

The palm oil-containing product comes from the refining of palm oil.

Surprisingly, it has been found that, although the fuels thus obtained have slightly lower calorific values, they contain less by-products resulting from the reaction, which have a disruptive effect on the use as fuel.

The interfering ingredients are especially in the reaction product solids, therefore, it is preferred that the fuel of the invention contains less than 5 mg residue / kg fuel on a 0.8 micron filter.

Suitable starting materials are in particular fatty acid-containing products with a content of free fatty acids (FFA)> 85 wt .-%. FFA is determined according to DIN EN 14104 (2003).

The fuel according to the invention has a calorific value of at least 35,000 joules / g, preferably the calorific value is somewhat higher, preferably at least 36,000 joules / g.

The biological fuel according to the invention is prepared by esterifying the palm oil fatty acid-containing starting materials, in particular PATH, with glycerol during the esterification, during which a reaction control takes place and the reaction is stopped if the content of tri-, di- and monoglycerides is in the range claimed according to the invention.

The invention is explained in more detail by the following examples.

example 1

12.36 t of PATH with an acid content of 89.3% by weight were reacted with 2.64 t of glycerol (content 80.97%). The compositions of the fatty acids in the PATH were as follows: palmitic acid: 47.6% by weight Oleic acid: 35.1% by weight linoleic acid: 9.7% by weight stearic acid: 4.3% by weight myristic: 1.2% by weight palmitoleic: 0.5% by weight linolenic acid: 0.4% by weight arachidonic acid: 0.3% by weight

Other acids ≤ 0.1% by weight.

The PATH was heated to 87 ° C and the glycerol added. The mixture was then heated to 230 ° C over 285 minutes, thereby forming an intermediate plateau at the temperature of 170-190 ° C. The pressure was 200 mbar.

During the reaction, the FFA content was determined continuously. The reaction was stopped after 390 minutes at an FFA content of 1.5%.

The mixture was pumped to a filtration unit using the heat of the mixture to preheat the next PFAD batch. At a temperature of about 130 ° C, a filtration was carried out with the addition of different grain sizes of perlites.

The product obtained had the following specification: Energy: 35509 y / g FFA: 1.2% monoglycerides: about 10% by weight diglycerides: about 35% by weight triglycerides: about 55% by weight.

Example 2

12.53 t of PATH with an acid content of 90% and the same percentage compositions of acids contained as in Example 1 were reacted with 2.47 t of glycerol (content 84.01% by weight). To remove short-chain fatty acids, an additional 100 kg of water was added. PATH was heated to 92 ° C and heated to 230 ° C over a period of 330 minutes. Again, a plateau formed at a temperature in the range of 180 to 190 ° C; the pressure amounts to approx. 200 mbar.

The FFA content was monitored continuously. At an FFA content of 1.5% after 420 minutes, the reaction was stopped.

It was cooled and filtered as in Example 1. The product obtained had the following specification: Energy: 25110 yr FFA: 1.5% monoglycerides: about 15% by weight diglycerides: about 35% by weight triglycerides: about 50 wt .-%.

Claims (6)

Biological fuel obtainable by esterification of palm oil fatty acid-containing educts with glycerol, the product being characterized by A calorific value of at least 35,000 joules / g, • a content of free fatty acids (FFA) ≤ 2 wt .-% and • a composition of 5 to 20% by weight of monoglycerides, - 30 to 40 wt .-% diglycerides and - 45 to 60 wt .-% triglycerides. Biological fuel according to claim 1, characterized in that a filter residue on a 0.8 micron filter <5 mg / kg. Biological fuel according to claim 1 or 2, characterized in that the palm oil fatty acid-containing educt has a content of free fatty acids (FFA)> 85 wt .-%. Biological fuel according to at least one of claims 1 to 3, characterized in that the calorific value is at least 36,000 Joule / g. A process for producing a biological fuel according to at least one of claims 1 to 4, characterized in that palm oil fatty acid-containing starting materials are esterified with glycerol. A method according to claim 5, characterized in that the palm oil fatty acid-containing starting materials have a content of free fatty acids (FFA)> 85 wt .-%.