WO2003016442A1

WO2003016442A1 - Transesterification device comprising an inclined reactor

Info

Publication number: WO2003016442A1
Application number: PCT/DE2002/002942
Authority: WO
Inventors: Bruno Berger
Original assignee: Bruno Berger
Priority date: 2001-08-14
Filing date: 2002-08-09
Publication date: 2003-02-27
Also published as: DE10138822A1; DE20113126U1

Abstract

The invention relates to a device and a method for the transesterification of triglycerides of saturated, unsaturated or polyunsaturated fatty acids (R1) of vegetable and/or animal origin comprising between 6 and 24 carbon atoms with a monovalent or polyvalent alcohol (R2-OH) comprising between 1 and 10 carbon atoms, to form esters of the general formula (I). In said formula, R1 represents a fatty acid group of vegetable and/or animal origin, or a saturated, unsaturated or polyunsaturated fatty acid group comprising between 6 and 24 carbon atoms and R2 represents a monovalent or polyvalent alcohol comprising between 1 and 10 carbon atoms. Said device and method comprise one or more assemblies (2) for transesterification, each assembly having one or more inclined reactors (5), connected in series or in parallel.

Description

Urnesterification device with inclined tube reactor

The present invention relates to a device and a method for the transesterification of fatty acid triglycerides of plant and / or animal origin with mono- or polyhydric alcohols with the features specified in the preamble of claim 1.

Fatty acids of vegetable or animal origin are usually present as esters of the trihydric alcohol glycerol, known as triglycerides.

A prerequisite for the usability of fatty acids of plant or animal origin as fuel for internal combustion engines is, among other things, that the individual fatty acids are not firmly connected to one another via a triglyceride bridge, but rather can be moved freely against one another.

In order to substitute the triglyceride group connecting three fatty acids, a transesterification reaction can be carried out, for example, with a monohydric alcohol under the action of a base.

For this purpose, a urnestertion device is known from the prior art, which comprises a reaction column to which a mixture of potassium hydroxide, methanol and rapeseed oil triglyceride is fed simultaneously.

The transesterified rapeseed oil methyl ester is taken off from the column bottom together with glycerol as a cleavage product. This known device for the transesterification of fatty acids of vegetable origin is disadvantageous in many ways:

A particularly serious disadvantage of this known device is its very low throughput. The production of rapeseed oil methyl ester, for example, is extremely time-consuming and ranges from 3 to 5 hours per ton.

Another significant disadvantage of this known device can be seen in the high reaction temperature of about 95 ° C. which is absolutely necessary there. On the one hand, this high reaction temperature requires an enormous amount of energy for heating purposes, which has an adverse effect on the operating costs.

On the other hand, the hot reaction containers pose a risk of burns that should not be underestimated, which is disadvantageous from the point of view of safety at the workplace.

This device belonging to the prior art is also disadvantageous because it has a particularly large number of separators,

Washing systems and lines and thus a high level of design effort.

This high design effort also leads to high manufacturing costs.

In addition, the space requirement of such a known plant for the transesterification of fatty acid triglycerides of plant origin is enormous. After all, the handling and operation of this previously known system are very tedious, cumbersome and time-consuming.

The object of the present invention is therefore to provide a device for the transesterification of fatty acid triglycerides of plant and / or animal origin with mono- or polyhydric alcohols, which allows a particularly high throughput with high product purity, which works at particularly low reaction temperatures and essentially at ambient pressure , whose operating costs are low, which is harmless even from the aspect of safety in the workplace, whose design and manufacturing costs are low and whose space requirement is particularly small.

According to the invention, this object is achieved in a generic device by the features specified in the characterizing part of patent claim 1.

Particularly preferred embodiments are the subject of the dependent claims.

Embodiments of the invention are described in more detail with reference to the drawings. Show it:

1 shows a schematic cross section through a catalyst mixing reactor used according to the invention for mixing the alcohol (R ₂ -OH) with a catalyst for the transesterification reaction, in particular with a base;

FIG. 2 shows a schematic cross section through an inclined tube reactor according to the invention with a bypass for the complete conversion of the reaction components; FIG. 3 shows a schematic cross section through a separator according to the invention for separating solids, impurities, accompanying substances, soaps or alcohol not used;

Figure 4 is a schematic flow diagram of a complete device according to the invention.

The device according to the invention is used in particular for

Transesterification of triglycerides, of saturated, unsaturated or polyunsaturated fatty acids (R) of plant and / or animal origin with 6 to 24 carbon atoms with a mono- or polyhydric alcohol (R ₂ - OH), preferably an alkanol, with 1 to 10 carbon atoms Esters of the general formula

0 // Rι-C-0-R ₂ ,

wherein Ri is a fatty acid residue of plant and / or animal origin or a saturated, an unsaturated or a polyunsaturated fatty acid residue with 6 to 24 carbon atoms and wherein R _{2 is} a mono- or polyhydric alcohol, especially an alkanol residue with 1 to 10 carbon atoms.

As can be seen in particular from FIG. 4, the device according to the invention for the transesterification of triglycerides generally comprises at least one or more arrangements (2) for the transesterification, each of which comprises one or more inclined tube reactors (5) connected in series or parallel to one another. FIG. 4 further shows that the device according to the invention for the transesterification of triglycerides, in particularly preferred embodiments, comprises one or more one-part or multi-part, upstream arrangements (1) for catalyst mixing.

As shown in FIG. 1, in this arrangement (1) for mixing the catalyst, the mixing of a ci to cio alcohol with a catalyst for a transesterification reaction and / or with a base, for example KOH or NaOH, can be carried out.

In general, the device according to the invention for the transesterification of triglycerides further comprises one or more arrangements (2) for the transesterification downstream of the arrangement (1) for catalyst mixing, which comprise one or more inclined tube reactors (5) connected in series or parallel to one another.

Preferably, the device according to the invention for the transesterification of triglycerides furthermore comprises one or more one or more part arrangements (3) downstream of the arrangement (2) for transesterification for washing out soaps and / or impurities and / or accompanying substances and / or of excess alcohol.

In particularly preferred embodiments of the device according to the invention for the transesterification of triglycerides, it can further comprise one or more one or more part arrangements (4) downstream of the washing arrangement (3) for drying and / or fine cleaning of the transesterified end product. The at least one arrangement (1) for catalyst mixing can comprise, for example, one or more bag emptying devices (6) for a preferably solid catalyst for a transesterification reaction and / or for a base, for example for KOH or NaOH.

In principle, all commercially available catalysts suitable for starting or accelerating a transesterification reaction can be used as catalysts. Particularly suitable catalysts for the transesterification of oils and fats are, for example, sodium or potassium methoxide, barium, potassium or sodium hydroxide, zinc silicate, lead oxide, zinc chloride, dihydrofluoroboric acid, lead oleate or calcium oxide.

Figure 4 shows that the arrangement (1) for catalyst mixing further one or more dry feeders (7), one or more mixing reactors (8) and one or more feed lines (10) for a liquid alcohol (R ₂ -0H), preferably for one Alkanol, can include in the mixing reactor (8). As a rule, the finished catalyst mixture flows into one or more mixing devices (9) for mixing with the fatty acid triglyceride to be transesterified.

Figure 1 in particular shows that the mixing reactor (8) can be designed in the form of a stirred tank reactor. Before ^¬ preferably are a stirred tank reactor or in this example, sieve-like container ehre- re integrated, in which the solids-shaped catalyst for a transesterification reaction and / or a base such as KOH or NaOH are vorlegbar. As a rule, the catalyst and / or the base ^"placed in the sieve-like ^{" container "can} be sprayed with a liquid alcohol (R ₂ -OH), preferably an alkanol, optionally via a spray lance or a spray head. The liquid reaction product can then drip through the sieve-like container into the stirred tank reactor and be homogenized there by an optional stirrer.

The alcohol / catalyst / base ratio may range, for example, from 20 to 1. The mixing time for the catalyst mixing is, for example, between 5 and 15 minutes and depends on the solubility or the moisture content of the catalyst / base.

Figure 4 shows that the arrangement (2) for transesterification one or more mixing devices (9) for mixing the catalyst reaction product (R ₂ -OH + catalyst / base) from the arrangement (1) for catalyst mixing with the u starching fatty acid triglyceride [(RiCOO) ₃ triglyceride]. The mixing device (9) is, for example, a static mixer.

Downstream of the mixing device (9), one or more heating devices (11) can be provided for heating the mixture and thus for increasing the reaction rate.

In order to increase the reaction rate, the mixture flowing out of the mixing device (9) can, for example, to a temperature in the range from 25 ° C. to 60 ° C., preferably in the range from 30 ° C. to 58 ° C., in particular in the range from 35 ° C. can be heated up to 55 ° C. Downstream of the mixing device (9) or the heating device (11), one or more stirred tank reactors (12) can be provided for the continuous or discontinuous as well as complete or at least partial transesterification.

The reactor outlet of the respective stirred tank reactor (12), in particular for the liquid transesterified reaction product, is preferably in the upper region of the stirred tank reactor (12).

As a rule, each stirred tank reactor (12) has at least one or more bypasses (13) for the at least partial recycling of reaction products which have not been or are not fully converted, and of glycerol formed as accelerator.

The at least one bypass (13) preferably begins in the stirred tank reactor discharge line (14) leading away from the stirred tank reactor (12) and opens into the lower region of the stirred tank (12).

The temperature in the stirred tank reactor (12) is, for example, in the range from 25 ° C. to 70 ° C., preferably in the range from 30 ° C. to 60 ° C., in particular in the range from 40 ° C. to 55 ° C.

Within the stirred tank reactor (12), the pressure can, for example, be in the region of the ambient pressure or be slightly larger or slightly smaller than this.

In the lowermost region of the stirred tank reactor (12) there are preferably one or more discharge openings which can be opened discontinuously or continuously to remove during the transesterification reaction _. resulting glycerin, like separation product, provided.

If appropriate, these lower discharge openings of the stirred tank reactor (12) are connected to a glycerine tank (13), for example via a disposal line (16).

In the stirred tank reactor (12), a particularly rapid and complete or at least partial transesterification of the fatty acid e-triglyceride to be transesterified takes place due to the elevated temperature (25 ° C. to 70 ° C.) and due to the turbulence.

A continuous volume flow of light and heavy phase (transesterified product, glycerol and transesterified fatty acid triglyceride) can preferably be drawn off through the bypass (13) on the stirred tank reactor (12). Due to the different specific weights of the transesterified product, the glycerol and the fatty acid triglyceride to be transesterified, the light and heavy phases are separated in the bypass - directly in the trousers.

The heavy fluid is pumped back into the stirred tank reactor (12) via the bypass (13) due to the suction effect of the stirring plate.

The light phase is preferably passed on via the trouser piece or the pipeline (14) into the first part of a downstream one-part or multi-part inclined tube reactor (5).

As a rule, the degree of transesterification after the stirred tank reactor (12) and before the inclined tube reactor (5) is in the range from 80.0% to 91.0%, preferably in the range from 81.0% to 89.0%, in particular in the range from 85.0% to 88.0%. It is shown in FIG. 4 that the device according to the invention for the transesterification of a fatty acid triglyceride downstream of an optionally present stirred tank reactor (12) can comprise one or more inclined tube reactors (5) connected in series or in parallel and operated continuously or discontinuously.

These are used in particular to complete the transesterification reaction, which may be only partial in the upstream stirred tank reactor (12), and to separate glycerol and / or soaps and / or impurities and / or accompanying substances and / or excess alcohol.

As a rule, at least one outlet of the at least one inclined tube reactor (5) is, for example, via a line (22) with an arrangement (3) which may be present for washing out soaps and / or contaminants and / or accompanying substances and / or excess alcohol Connection.

As a rule, each inclined tube reactor (5) comprises one, two, three, four, five, six, seven, eight, nine, ten or more inclined tubes (17). The inclined tubes (17) are preferably aligned such that they cut the horizontal at an acute angle in the range from 40 ° to 80 °, preferably in a range from 45 ° to 78 °, in particular in a range from 55 ° to 75 ° ,

The inclined tubes (17) of each inclined tube reactor (5) can be aligned parallel to one another or can intersect or can be connected to one another with respect to their entirety or at least in the region of their lower sections in an essentially Y or V manner (see FIG. 2). As a rule, the incomplete or incompletely converted reaction products and, if appropriate, glycerol from the stirred tank reactor (12) for the transesterification flow into the upper end of the inclined tube (17).

The completely or at least almost completely transesterified reaction product can then flow out of the upper end (s) of the other inclined pipe (s) (17).

In the meantime, in the lower area of each inclined tube reactor (5), for example, glycerin or the respective cleavage product can accumulate, which flows continuously or discontinuously through one or more outlet openings (19), for example into a disposal line (16) for glycerin.

At the end of the continuous process, an enriched glycerol phase with a glycerol content of 50 to 85% is obtained.

Each inclined tube reactor (5) preferably comprises one or more bypasses (18) in its central region and / or in its lower region for connecting the inclined tubes (17) to one another (see FIG. 2).

As a rule, the bypass (18) is oriented essentially horizontally and serves to shorten the flow path, in particular of the completely transesterified reaction product, and to increase the throughput.

In particularly preferred embodiments of the device according to the invention for the transesterification of fatty acid triglycerides, each inclined tube (17) of an inclined tube reactor (5) through which reaction products and glycerol which are not or not completely transesterified can be added to the respective one Inclined tube reactor (5) are supplied, comprise one or more fluidizing devices, optionally in the form of cascades (20) for separating glycerol and for fluidizing the reaction mixture and thus for increasing the reaction rate and increasing the throughput.

The flow rate through this inclined inlet pipe (17) with swirling device (20) is, for example, in the range from 0.01 m per second to 0.8 m per second, preferably in the range from 0.02 m per second to 0.5 m per second, especially in the range of 0.03 m per second to 0.4 m per second.

In particularly preferred embodiments of the present invention, each inclined tube (17) of the inclined tube reactor (5) through which the completely or almost completely transesterified reaction product flows out of the respective inclined tube reactor (5) can have baffles (21) for the retention of, if necessary existing solids.

The swirling devices, optionally in the form of cascades (20), in the upstream

Inclined tube (17) of the inclined tube reactor (5) serves in particular as a flow breaker and brings about a quick and successful phase separation.

As a result, the lighter transesterified end product separates from the heavier glycerol phase, the heavier glycerol phase collecting at the flow rate in the range from 0.01 m per second to 0.8 m per second at the bottom of the inclined tube reactor (5). The transesterified reaction product can get into the second part of the inclined tube reactor (5) more quickly via the bypass line (18), if any, due to its lower flow resistance and its lower specific weight.

There, by means of the continuous or section-wise baffle surfaces (21), which are designed, for example, in the form of baffle plates or an inclined, rigid or rotating static mixer, a swirl can again be brought about, whereby the rest of the fatty acid triglyceride that has not yet been transesterified, possibly still present further esterified in this area.

When leaving the first inclined tube reactor (5), the reaction mixture has a degree of transesterification of approximately 94-95%.

After passing through the first inclined tube reactor (5), the reaction mixture is preferably passed into a second inclined tube reactor (5), in which the same process as in the first inclined tube reactor (5) takes place.

At the end of the inclined tube reactor stage, that is to say upon exiting the third inclined tube reactor (5), for example, there is a reaction product with a degree of transesterification in the range from 99.5 to 99.9%.

Due to this continuous process, these special hydrodynamic conditions and in particular due to the inclined tube reactor stage, the esterification time is in the smallest case about 15 minutes, but at most 45 minutes, with the catalyst mixture being mixed with the fatty acid to be esterified over a period of 45 minutes -Triglyceride is already included. The arrangement (3), optionally downstream of the arrangement (2) for transesterification, for washing out soaps and / or impurities and / or accompanying substances and / or excess alcohol can be one or more, optionally cyclone-like separators (23 ) or vertical separators for separating solids and / or impurities and / or accompanying substances (see FIGS. 3 and 4).

In addition to this, the device according to the invention can comprise one or more separators (23) which are flushed in countercurrent or in cocurrent with water or another liquid medium in order to remove soaps and / or alcohol (R ₂ -OH) and / or accompanying substances and / or wash out impurities from the reaction mixture supplied to the respective separator (23).

As an alternative or in addition to this, the separator (s) (23) can be flushed with a gaseous medium, for example C0 ₂ , for conditioning the washing medium in order to neutralize excess catalyst or excess base.

As a rule, the reaction mixture, if appropriate mixed with water or another liquid medium, flows after the separators (23) have passed through a device (4) for drying and fine cleaning.

The almost pure transesterified product flowing out of the arrangement (2) for transesterification is preferably fed to a separator battery (23), which are usually designed as vertical separators in which the input ^{substances are} separated from one another ^¬ due to their different densities. The washing water optionally used to rinse the separators (23) has the property of binding the alcohol content (maximum 50%) and also soap residues by means of a solution. In addition, the washing water can, after prior conditioning, serve to inactivate excess catalysts, in particular bases, by neutralization.

If necessary, the alcohol can then be distilled off from the wash water and returned to the process. The cleaned and, if necessary, further processed washing water can, if appropriate, be continuously returned to the process.

FIG. 4 shows that the device according to the invention for the transesterification of fatty acid triglycerides further comprises an arrangement (4) for drying and fine cleaning, for example in the form of a distillation device (24) for separating off the water or other liquid added in the separator (s) (23) Media as well as excess, unreacted alcohol.

An outlet of the most downstream separator (23) of the arrangement (3) for washing may open directly or indirectly into this distillation device (24).

One or more outlets for glycerol can be present in the bottom area of the distillation device (24). The distillation device (24) which may be present can be filled with packing elements and / or have an inner tube which may be heated.

The distillation column (24) can be constructed in two stages and preferably have two different temperature zones, one in the upper part of the column Temperature zone, for example in the range from about 110 ° C to 140 ° C and in the lower part of the column, for example in the range from 50 ° C to 85 ° C.

The formation of at least two temperature zones in the distillation column (24) is advantageous both in order to evaporate methanol, which may still be bound in excess in the transesterified product, and in order to separate excess water from the transesterified reaction product.

If necessary, the evaporated alcohol and the evaporated water are each condensed in a container, the alcohol is separated from the water and water and alcohol are fed back into the process.

In particularly preferred embodiments of the present invention, the arrangement (4) for drying and fine cleaning further comprises one or more separators downstream of the distillation device (24)

(23) for the separation of any glycerin still present and any traces of impurities.

Furthermore, the arrangement (4) for dry and fine cleaning can comprise one or more filters (25) or membrane filters or sieve filters downstream.

In a particularly preferred embodiment of the present invention, the arrangement (4) for drying and / or fine cleaning can additionally comprise a container (26) for the transesterified reaction product, which on the one hand is directly or indirectly connected to the distillation device (24) and on the other hand one or has several exit options, which with the arrangement (3) for washing and / or with the Inclined tube reactors (5) or with the stirred reactor (s) (12) in connection to allow adjustment of the entire system, especially in the start-up phase.

If necessary, the quality of the transesterified end product can be determined in the container (26). If the transesterified product in the container (26) is not of the expected quality, it can be returned to the corresponding area of the process (see FIG. 4).

This possibility of feedback is particularly advantageous for starting up the system, since the technically specific parameters first have to be adjusted when starting up the system.

The present invention further relates to a process for the transesterification of fatty acid triglycerides of plant and / or animal origin with 6 to 24 carbon atoms with mono- or polyhydric alcohols, in particular alkanols, with 1 to 10 carbon atoms in the presence of a catalyst for a transesterification reaction and / or a base.

An essential feature of the process according to the invention is that the transesterification reaction takes place completely or partially in one or more inclined tube reactors (5) connected in series or in parallel to one another, in that in each inclined tube reactor (5) designed according to the above, a fatty acid to be converted Triglyceride of the general formula

H

wherein Ri is a saturated, mono- or polyunsaturated fatty acid residue of vegetable or animal origin with 6 to 24 carbon atoms with a mono- or polyhydric alcohol (HO-R ₂ ), in particular with an alkanol, with 1 to 10 carbon atoms in the presence of a catalyst for one Transesterification action and / or a ^'' Ba'se - such as KOH or a NaOH - and optionally in the presence of an accelerator such as glycerol is reacted.

The reaction temperature is, for example, in the range from 25 ° C. to 70 ° C., preferably in the range from 30 ° C. to 60 ° C., in particular in the range from 40 ° C. to 55 ° C. The transesterification is preferably carried out at ambient pressure or at a slightly higher pressure or at a slightly lower pressure.

The flow rate of the reaction mixture flowing through the inlet inclined tube (17) with swirling device (20) of the inclined tube reactor (5) is preferably in the range from 0.01 m per second to 0.8 m per second, preferably in the range from 0.02 to 0.5 m per second, especially in the range of 0.03 to 0.4 m per second. In detail, the method according to the invention can include the following method steps:

As a rule, a catalyst is first mixed, for example in an arrangement (1) described above, for mixing the catalyst by mixing a catalyst for a transesterification reaction and / or a base (for example KOH or NaOH) with a mono- or polyhydric alcohol (HO-R ₂ ), in particular an alkanol with 1 to 10 carbon atoms, in a mixing reactor (8), which is optionally in the form of a stirred tank reactor.

The catalyst mixture [alcohol (H0-R ₂ ) and catalyst / “bubble] is preferably subsequently mixed with a fatty acid triglyceride [R _α COO) ₃ - triglyceride] to be transesterified] in a mixing device (9) which is in the form of a static mixer.

This can be followed by at least a partial reaction (transesterification reaction) of the alcohol (HO-R ₂ ) with the fatty acid triglyceride [(RiCOO) ₃ triglyceride] to be transesterified in the presence of a catalyst and / or a base and, if appropriate, an accelerator (Glycerol), for example in a system (2) for the transesterification described in more detail above, optionally with one or more stirred tank reactors (12).

The temperature within such a stirred tank reactor (12) is, for example, in the range from 25 ° C. to 70 ° C., preferably in the range from 30 ° C. to 60 ° C., in particular in the range from 40 ° C. to 55 ° C. The transesterification reaction taking place in the stirred tank reactor (12) is preferably carried out at ambient pressure or at a pressure which is only slightly higher or lower than the ambient pressure.

Following the at least partial transesterification in the stirred tank reactor (12), a complete or almost complete reaction of the alcohol (HO-R ₂ ) with the fatty acid triglyceride to be transesterified [(RiCOO) ₃ -triglyceride] in the presence of a catalyst and / or in several stages can be carried out or a base and optionally an accelerator (glycerol) in a system (2) for transesterification with one or more of the inclined tube reactors (5) described above.

The flow rate of the reaction mixture flowing into the inclined tube reactor (5) is in the inlet region of the inclined tube reactor (5), for example in the range from 0.01 m per second to 0.8 m per second, preferably in the range from 0.02 rα per second to 0, 5 m per second, in particular in the range from 0.03 m per second to 0.4 m per second.

The temperature inside the inclined tube reactor (5) is, for example, in the range from 25 ° C. to 70 ° C., preferably in the range from 30 ° C. to 60 ° C., in particular in the range from 40 ° C. to 55 ° C.

Within the inclined tube reactor (5), the pressure essentially corresponds to the ambient pressure, for example, or is only slightly higher or lower than this.

Following the essentially complete transesterification (approximately 99.0 to 99.9%), the reaction mixture can be washed out and soaps and / or contaminants separated off. conditions and / or accompanying substances and / or unreacted alcohol in an arrangement (3) described above for washing out.

Such an arrangement (3) for washing out preferably comprises one or more separators (23) which are optionally flushed with water in countercurrent or cocurrent or are flushed with other liquid and / or gaseous media.

In the downstream connection there can be drying and fine cleaning of the completely or almost completely transesterified reaction mixture in a system (4) described above for drying and fine cleaning.

Such a system (4) for drying and fine cleaning can comprise, for example, a distillation device (24) for separating off the water or other liquid medium added in the separator (s) (23) and excess alcohol (HO-R ₂ ).

For the same purpose, the reaction mixture after passing through the distillation column (24) can optionally flow through one or more separators (23) and optionally through one or more downstream filters (25).

In summary, it can be stated that the device according to the invention allows the transesterification of fatty acid triglycerides of plant and / or animal origin with mono- or polyhydric alcohols in an effective manner.

An essential advantage of the device and the method according to the invention is a particularly high throughput: While the above-mentioned device of the prior art takes 3 to 5 hours to produce a ton of transesterification product (biodiesel), in the case of the device according to the invention a very short period of only 45 minutes is sufficient for the production of a ton of transesterification product (biodiesel), which this also results in excellent quality and purity (99.5 to 99.8% transesterification), which even corresponds at least to the applicable standard for "biodiesel" according to the German industrial standard DIN 51606.

Another advantage of the device according to the invention and of the method according to the invention can be seen in the particularly low reaction temperatures in the range from 25 ° C. to 70 ° C.

For heating purposes, therefore, no enormous energy expenditure is required. This is particularly noticeable in terms of operating costs. There is also no pronounced risk of burns from the reaction containers. This fact is particularly advantageous from the point of view of safety in the workplace.

The fact that the device according to the invention and the method according to the invention essentially work at ambient pressure is of outstanding advantage from a safety point of view.

A significant advantage of the device according to the invention and of the method according to the invention can finally be seen in the particularly low design complexity of the device according to the invention, which is reflected in low production costs. It is also particularly advantageous in the case of the device according to the invention that its mass is dramatically less than the mass known in the prior art device.

Claims

claims

1. Device for the transesterification of triglycerides of saturated, unsaturated or polyunsaturated fatty acids (Ri) of plant and / or animal origin with 6 to 24 carbon atoms with a mono- or polyhydric alcohol (R ₂ -OH) with 1 to 10 carbon atoms to form the esters general formula

wherein Ri is a fatty acid residue of vegetable and / or animal origin or a saturated, an unsaturated or a polyunsaturated fatty acid residue with 6 to 24 carbon atoms and wherein R _{2 is} a mono- or polyhydric alcohol with 1 to 10 carbon atoms, characterized in that it comprises one or more arrangements (2) for transesterification, each comprising one or more inclined tube reactors (5) connected in series or parallel to one another.

2. Device according to claim 1, characterized in that it comprises:

- A one-part or multi-part, upstream arrangement

(1) for catalyst mixing, that is to say for mixing a Ci to Cι ₀ alcohol with a catalyst for a transesterification reaction and / or with a base such as KOH or NaOH, one or more arrangements (2) for transesterification downstream of the arrangement (1) for catalyst mixing, which comprise one or more inclined tube reactors (5) connected in series or parallel to one another,

- One or more of the arrangement (2) for transesterification downstream one or more part arrangements (3) for washing out soaps and / or contaminants and / or accompanying substances and / or excess alcohol and

- One or more of the arrangement (3) for washing downstream one or more part arrangements (4) for drying and / or fine cleaning of the transesterified end product.

3. Device according to one or more of the preceding claims, characterized in that the arrangement (1) for catalyst mixing comprises:

- One or more bag emptying devices (6) for a solid catalyst for a transesterification reaction and / or for a base such as KOH or NaOH; - one or more dry material feeders (7),

- One or more mixing reactors (8) and

- One or more feed lines (10) for a liquid alcohol (R ₂ -OH) in the mixing reactor (8),

the finished catalyst mixture flowing into one or more mixing devices (9) for mixing with the fatty acid triglyceride to be transesterified.

4. Device according to one or more of the preceding claims, characterized in that the mixing reactor

(8) is in the form of a stirred tank reactor in which one or more sieve-like containers are integrated, in which the solid catalyst for a transesterification reaction and / or a base such as KOH or NaOH can be placed, the catalyst placed in the sieve-like container and / or the base can optionally be sprayed with a liquid alcohol (R ₂ -OH) via a spray lance or a spray head and the liquid reaction product drips through the sieve-like container into the stirred tank reactor and can be homogenized there by a stirrer.

5. The device according to one or more of the preceding claims, characterized in that the arrangement (2) for transesterification comprises:

- One or more mixing devices (9) for mixing the catalyst reaction product (R ₂ -OH + catalyst / base) from the arrangement (1) for catalyst mixing with the fatty acid triglyceride to be transesterified [(RiCOO) ₃ - triglyceride], - one or a plurality of heating means (11) for heating the mixture to a temperature ranging from 25 ° C to 60 ° C, and thus increasing the reaction rate, - one or more stirred tank reactors (12) for the continuous or discontinuous and completeness, ^¬ ended or at least partially transesterification , The reactor outlet of the respective stirred tank reactor (12), in particular for the liquid and at least partially transesterified reaction product, being in the upper region of the stirred tank reactor (12), each stirred tank reactor (12) has at least one or more bypasses (13) for the at least partial recycling of incompletely or incompletely converted reaction products and of glycerol formed (as accelerator), the at least one bypass (13) possibly in the stirred tank reactor leading away from the stirred tank reactor (12) - Gate discharge line (14) begins and opens into the lower area of the stirred tank (12) and the temperature in the stirred tank reactor (12) is in the range from 25 ° C to 70 ° C and the pressure inside the stirred tank reactor ( 12) is in the range of the ambient pressure or is slightly higher or slightly lower than this, and in the lowest area of the stirred tank reactor (12) one or more discontinuously or continuously open drain openings are provided for the removal of glycerol accumulating during the transesterification reaction, which are via a disposal line ( 16) are connected to a glycerin tank (13) one or more inclined tube reactors (5) connected in series or in parallel and operated continuously or discontinuously to complete the transesterification reaction which may be only partial in the upstream stirred tank reactor (12) and to separate glycerol and / or soaps, with at least one outlet of the at least one inclined tube reactor ( 5) is connected via a line (22) to an arrangement (3) for washing out soaps and / or impurities and / or accompanying substances and / or excess alcohol.

6. The device according to one or more of the preceding claims, characterized in that the or the inclined tube reactors (5) one, two, three, four, five, six, seven, eight, nine, ten or more straight or curved inclined tubes (17) comprise, which are aligned at an acute angle in the range from 40 ° to 80 ° or intersect them at such an acute angle, the inclined tubes (17) being aligned parallel to one another or tapering towards one another with respect to their lower sections cut or are connected to one another in their entirety or at least in the area of their lower sections in a Y- or V-like manner, the reaction products which have not or not fully been converted and, if appropriate, glycerol from the stirred tank reactor (12) in the upper end of the one inclined tube (17) flow in for the transesterification and completely from the upper end (s) of the other inclined pipe (s) (17) constantly flow out or at least almost completely transesterified reaction products, whereas accumulates (5) glycerin in the lower portion of each inclined tube reactor comprising a plurality of outlet openings (19) flows continuously or intermittently through one or into a disposal line (16) for glycerol.

7. The device according to one or more of the preceding claims, characterized in that each inclined tube reactor (5) in its central region and / or in its lower region comprises one or more bypasses (18) for connecting the inclined tubes (17), each bypass (18) is aligned essentially horizontally and serves to shorten the flow path of the completely transesterified reaction product and thus to increase the throughput.

8. The device according to one or more of the preceding claims, characterized in that each inclined tube (17) of the inclined tube reactor (5) through which not or not completely transesterified reaction products and glycerol are fed to the respective inclined tube reactor (5), one or more swirling devices, if necessary in the form of cascades (20) or stairs for separating glycerol and for swirling the reaction mixture and thus for increasing the reaction rate, the flow rate through this inlet inclined tube (17) with swirling device (20) in the range of 0.01 m per second to 0.8 m per second.

9. The device according to one or more of the preceding claims, characterized in that each inclined tube (17) of the inclined tube reactor (5) through which the completely or almost completely transesterified reaction product flows out of the respective inclined tube reactor (5) with baffles (21) for the reluctance of any solids that may still be present.

10. The device according to one or more of the preceding claims, characterized in that the arrangement (2) for transesterification downstream of the arrangement (3) for washing out soap and / or impurities and / or accompanying substances and / or excess alcohol comprises: one or more, optionally cyclonic separators (23) or vertical separators connected in series or parallel to one another for separating solids and / or impurities and / or accompanying substances,

- One or more separators (23), which are rinsed in countercurrent or in cocurrent with water or another liquid and / or gaseous medium, soaps and / or alcohol (R ₂ -OH) and / or accompanying substances and / or impurities each one

Wash out separator (23) fed reaction mixture, the rinsing of the separator (23) and / or the washing medium with a gaseous medium such as C0 ₂ optionally for conditioning the washing medium for neutralizing excess catalyst or excess base, and which optionally with water or a other liquid medium mixed reaction mixture flows in after passage of the separators (23) of a device (4) for drying and fine cleaning.

11. The device according to one or more of the preceding claims, characterized in that the arrangement (4) for drying and fine cleaning comprises:

- A distillation device (24) for separating the water or other liquid media added in the separator (s) (23) and excess, not transesterified alcohol, an outlet of the most downstream separator (23) of the arrangement (3 ) opens directly or indirectly for washing and one or more outlets for. in the lowest area of the distillation device (24) Glycerol are present and the distillation device (24) can be filled with packing elements and / or has an optionally heatable inner tube and

- If appropriate, one or more separators (23) connected downstream of the distillation apparatus (24) for separating any glycerol and residual traces of impurities and

- One or more downstream filters (25) or membrane filters or sieve filters.

12. The device according to one or more of the preceding claims, characterized in that the arrangement (4) for drying and / or fine cleaning additionally comprises:

- A container (26) for the transesterified reaction product, which is on the one hand directly or indirectly connected to the distillation device (24) and on the other hand has one or more outlet options, which with the arrangement (3) for washing and / or with the inclined tube reactor (s) (5) and / or with the stirred tank reactor (s) (12) in order to enable adjustment of the entire system, in particular during the start-up phase.

13. Process for the transesterification of fatty acid triglycerides of plant and / or animal origin with 6 to 24

Carbon atoms with mono- or polyhydric alcohols with 1 to 10 carbon atoms, characterized in that the transesterification reaction takes place completely or partially in one or more inclined tube reactors (5) connected in series or parallel to one another, in each Inclined tube reactor (5) according to claims 6, 7, 8 or 9, a fatty acid triglyceride to be transesterified of the general formula:

H

wherein R _{x is} a saturated, monounsaturated or polyunsaturated fatty acid residue of vegetable and / or animal origin with 6 to 24 carbon atoms with a mono- or polyhydric alcohol (HO-R ₂ ) with 1 to 10 carbon atoms in the presence of a catalyst for a transesterification reaction and / or a base such as KOH or NaOH and optionally in the presence of an accelerator such as glycerol at a temperature in the range from 25 ° C to 70 ° C and at ambient pressure or at slightly higher pressure or at a slightly lower pressure and at a flow rate through the inlet - Inclined tube (17) with swirling device (20) in the range from 0.01 m per second to 0.8 m per second is brought to react with one another.

14. The method according to claim 13, characterized in that it comprises the following method steps: - Mixing a catalyst in an arrangement (1) for catalyst mixing according to claims 3 or 4 by mixing a catalyst for one

Transesterification reaction and / or a base (KOH, NaOH), with a mono- or polyhydric alcohol (HO-R ₂ ) having 1 to 10 carbon atoms, in a mixing reactor (8), which is optionally in the form of a stirred tank reactor,

- Mixing the catalyst mixture [alcohol (HO-R ₂ ) and catalyst / base] with a fatty acid triglyceride [RiCOO) ₃ triglyceride] to be transesterified] in a mixing device (9) which may be in the form of a static mixer,

- At least partially, one-step or multi-step reaction of the alcohol (H0-R ₂ ) with the fatty acid triglyceride to be transesterified [(RiCOO) ₃ -triglyceride] in the presence of a catalyst and / or a base and, if appropriate, an accelerator (glycerol) in one plant (2) for transesterification with a stirred tank reactor (12) according to claim 5, at a temperature in the range from 25 ° C to 70 ° C, preferably in the range from 30 ° C to 60 ° C, in particular in the range from 40 ° C to 55 ° C, as well as at ambient pressure or a pressure that is slightly higher or lower than the ambient pressure,

- Complete or almost complete, one-step or multi-step reaction of the alcohol (HO-R ₂ ) with the fatty acid triglyceride to be transesterified [(R _α COO) ₃ triglyceride] in the presence of a catalyst and / or a base and optionally an accelerator (glycerol) in a plant (2) for transesterification with one or more inclined tube reactors (5) according to claims 6, 7, 8 or 9 at a flow rate in the inlet area of the inclined tube reactor (5) in the range of 0.01 m per second to 0.8 m per second, preferably in the range from 0.02 m per second to 0.5 m per second, in particular in the range from 0.03 m per second to 0.4 m per second and at a temperature in the range from 25 ° C to 70 ° C, preferably in the range from 30 ° C to 60 ° C, in particular in the range from 40 ° C to 55 ° C and a pressure which essentially corresponds to the ambient pressure or is slightly higher or lower than this is, and downstream thereof - a washing out of the reaction mixture and separation of soaps and / or impurities and / or accompanying substances and / or unreacted alcohol in a washing out arrangement (3) according to claim 10, which comprises one or more separators (23) , which are optionally rinsed in countercurrent or cocurrent or rinsed with another liquid and / or gaseous medium, and downstream thereof - a drying and fine cleaning of the completely or almost completely transesterified R Reaction mixture in a plant (4) for drying and fine cleaning according to claim 11, by distillation in a distillation device (24) for separating the water or other liquid medium added in the separator (s) (23) and excess alcohol (HO- R ₂ ) and optionally through one or more separators (23) downstream of the distillation device (24) for separating glycerol and / or accompanying substances and / or impurities and optionally through one or more downstream filters (25).