DE102007026654A1 - Preparing fatty acid alkyl esters and glycerin comprises preparing a catalyst containing a basic component and alcohol, making an activated catalyst, mixing triglycerides with the activated catalyst and contacting the reactants - Google Patents

Abstract

Preparation of fatty acid alkyl esters and glycerin by transesterification process, comprises preparing a catalyst that contains a basic component and alcohol, making an activated catalyst in such a way that a coemulsifier dissolves in the prepared homogeneous catalyst, mixing the triglycerides with the activated catalyst, and contacting the reactants during the transesterification process in a paper or in flow reactor, under a condition that promotes increased contact between the reactants. Preparation of fatty acid alkyl esters and glycerin by transesterification process, comprises: either preparing a catalyst that contains a basic component and alcohol, making an activated catalyst in such a way that a coemulsifier dissolves in the prepared homogeneous catalyst, mixing the triglycerides with the activated catalyst, and contacting the reactants during the transesterification process in a paper or in flow reactor, under a condition that promotes increased contact between the reactants; or making an activated agent in such a way that the coemulsifier dissolves in the alcohol, mixing the triglycerides with the activated agent, and contacting the reactants during the transesterification process under a condition that promotes increased contact between the reactants, in a flow reactor or in serially arranged flow reactors, which contain a heterogeneous transesterification catalyst. Independent claims are included for: preparing fatty acid alkyl esters using the esterification process, comprising either: making an activated agent in such a way that the coemulsifier dissolves in the alcohol, mixing the activated agent with a homogeneous acid catalyst for making activated catalyst, mixing carboxylic acids with the activated catalyst, and contacting the reactants during the transesterification process in a paper or in flow reactor, under a condition that promotes increased contact between the reactants; and making an activated agent in such a way that the coemulsifier dissolves in the alcohol, mixing carboxylic acids with the activated agent, and contacting the reactants during the transesterification process under a condition that promotes increased contact between the reactants, in a flow reactor or in serially arranged flow reactors, which contain a heterogeneous transesterification catalyst; or making an activated agent in such a way that the coemulsifier dissolves in the alcohol, mixing an activating agent with the triglyceride, which contains free carboxylic acids, at the end of the esterification process under a condition that promotes increased contact between the reactants, in a flow reactor or in serially arranged flow reactors, which contain a heterogeneous transesterification catalyst, and mixing the activating agent of the triglyceride, which contains converted alkyl esters from fatty acids, at the end of the transesterification process, under a condition that promotes increased contact between the reactants, in a flow reactor or in serially arranged flow reactors, which contain a heterogeneous transesterification catalyst.

Description

The The invention relates to a process for the preparation of fatty acid alkyl esters, and glycerin using the transesterification process.

The Application of alkyl esters recorded in the biofuels market a constant growth. It is expected that by 2010 only in Europe the share of biofuels in transport by more than 6% grows. The increased consumption and demand make the optimization of the current production capacities necessary for alkyl esters. The invention relates to the method for the preparation of fatty acid alkyl esters, as components diesel fuels or as biodiesel fuels can. It will be new knowledge and experience applied to the field of colloid chemistry with a new line of sight on the mechanism of transesterification and esterification. This mechanism has been expanded in the sense that it is now a new, feasible method for the production of alkyl esters in a broad industrial application in homogeneous-based processes and heterogeneous catalysts.

reactions for the direct conversion (transformation) of vegetable oils or animal fats in fatty acid alkyl esters and glycerol have been known for several years. Currently Above all, interest in the production of methyl esters is growing or ethyl esters of vegetable oils such as rapeseed, Soy, sunflower, olive and other vegetable oils, also from animal fats, from commodities of used frying oils and fats whose quality no longer suitable for food.

Today's commercially produced fatty acid alkyl esters used in current diesel internal combustion engines must meet strict quality parameters. So z. B. in the European Standard Method EN 14105 / EN 14103 , a minimum content of methyl ester of 96.5% hm (mass) is required. In addition, the maximum permissible levels of mono-, di- and triglycerides, free glycerol and of metals and phosphorus are limited.

In general, the process of transesterification can be represented by the following stoichiometric reaction of vegetable oil:

The process of transesterification of triglycerides into methyl esters of fatty acids is in 1 shown as a catalyzed reaction.

Around To achieve a high degree of conversion is in the reactions the transesterification a high excess of methanol necessary. As conventional catalysts are both homogeneous as well as or heterogeneous catalysts used.

The basic catalysts are selected from the group of hydroxides (NaOH, KOH), alkoxides (sodium methoxide, potassium methoxide), the z. In H. Kreutzer, J. Am. Oil. chem. soc. 61 (1984) 343 are listed.

The However, transesterification can also be done using acid Catalysts such as hydrochloric acid, sulfuric acid or Sulfonic acid take place, also using metallic Bases, such as As titanium alkoxides or tin, magnesium or zinc oxides. These mentioned catalysts are used in the homogeneous phase, go into the reaction products and must Therefore, after the expiration of methanolysis with the help of a purifying Neutralization step can be removed again from the reaction product.

Sodium methoxide and also potassium methoxide are often used as the homogeneous catalyst. As well as from the product (alkyl ester) must also from the glycerol phase (the glycerol product) after the reaction, the sodium or potassium methoxide as resulting sodium or potassium soaps of fatty acids be be sideways. This is done by acidification with an inorganic acid (hydrochloric acid or phosphoric acid). In this case, the fatty acids and the glycerin, which still contains salts such as sodium chloride, sodium diphosphate, potassium chloride or potassium diphosphate, separated from each other. Depending on the process, final glycerine can be obtained in a concentration of 70-95%.

The Forming soaps of fatty acids not only reduces the alkyl ester yield by more than 1% of the alkyl ester production, but also complicates the process of separation of the product from the glycerol phase. The separator, after the reactor of transesterification installed becomes a vulnerability, the longer one Settling or the use of a more expensive separator, z. B. a centrifuge, which increases the overall cost.

at different methods of transesterification is therefore the quality of the input raw material triglyceride, vegetable oil, animal Fat according to its content of free fatty acids with a Acid value of less than 1 mg KOH / g and a water content limited by less than 0.3%.

Existing patents

The Endeavor to accelerate the reaction speed Transesterification reactions were reflected in several patented reactions Solutions.

patent CA 2131654 (1994)

The patent CA 2131654 (1994) Boocock, David GB Canada (Process for Producing Lower Alkyl Fatty Acid Esters) published a method which should increase the reaction rate of transesterification by 15-fold, due to the presence of a cosolvent and the creation of a single-phase system of reactants. As co-solvents, cyclic ethers such as 1,4-dioxane, tetrahydrofuran and metylterobutyl ether are listed. Since the addition of the cosolvent increased the volume flow of the reactants in the plant by more than 25%, and since it was necessary to eliminate this additive by distillation after completion of the reaction, and because of the risk associated with the manipulation with ether found the proposed processes are not used in real technologies.

patent US 6712867 / B-1 (2004), patent CA 2316141 (2000)

New insights into the reactions of transesterification in a dilute environment of the reactants gave rise to further patented solutions. For example the patent US 6712867 / B-1 (2004) and the patent CA 2316141 (2000) Boocock, David GB Canada, where the creation of the single-phase system of reactants by the addition of alkanol in a high molar ratio of triglycerine from 15: 1 to 35: 1 and by the addition of a co-solvent (cyclic ether) in a smaller amount is solved so that a single-phase system of the reactants is formed. Also, this solution did not eliminate the deficiency that we have cited in the previous patent.

patent WO 2004 085585 A1 , Patent US 2006 0293532 A1

In connection with the system of transesterification in the diluted environment of the reactants are also other patented solutions such as WO 2004 085585 A1 . US 2006 0293532 A1 Lee, Jin-Suk: KR and others (Manufacturing Method of BIO-DIESEL OIL), where the transesterification of the triglycerides into alkyl esters occurs with up to 30% addition of the final product alkyl ester, which is at the beginning of the transesterification reaction or at the beginning the esterification reaction is added. As in the previous patent, this patented method also utilizes a large excess of solvent additive, requiring the expansion of flow capacity at all junctions of the technical plant, thus resulting in increased costs for building a higher capacity plant as well as higher operating costs Has.

patent US 2003/0032826 A1

Another patent solution Pat US 2003/0032826 A1 Milford A. Hanna Lincoln, NE (Transesterification Process for Production of Biodiesel) describes a method of producing fatty acid alkyl esters from triglycerides and a continuous manufacturing plant. The subject of the patent solution is the use of a Venturi ejector, which forms as a construction element a series of sequentially ordered reaction zones, ie mixing elements in the pipeline. At the narrowest point of the Venturi ejector, where the flow is formed at the highest speed, either only alcohol or alcohol is added together with a homogeneous catalyst.

The protected method in the patent is characterized that in the place of addition of alcohol components of a reactant have such a speed that a turbulent flow arises, characterized by the limit of the Reynolds number is at least around 2100 to 4000.

These Patent solution uses only the already known knowledge about accelerating transesterification reactions can be when the components of the reactants in one greater mutual contact if the Conditions for greater turbulence be created (different mixing speeds, larger Shearing forces by different mixers and other facilities).

patent US 2005/0108927 A1

Another patent solution Pat US 2005/0108927 A1 Kandukalpatti Chinnaraj Velappan and others (IN) (Process for the Preparation of BIO-DIESEL) protects the method of producing biodiesel fuel, which can take less than 50 hours. The fuel may be used as a component of conventional fuels for diesel internal combustion engines. The transesterification conditions according to patent, the reaction temperature above the boiling point of the alcohol used, not higher than 215 ° C in turbulent mixing at a value of Reynold number (N _Re ) of not less than 4000, the reaction time of not less than 30 minutes, with an alcohol excess of 8-42% by mass, long separation cycles of the product from the glycerol phase. The reaction conditions specified in the patent require closed reactor plants. These systems must be designed for pressures above the vapor pressures of the alcohol used for transesterification.

patent WO 2006/002087 , Patent US 2005/0274065 A1

Another patent solution WO 2006/002087 . US 2005/0274065 A1 Marc A. Portnoff, Pittsburgh, PA (US) and others (Methods for Producing BIODIESEL) are concerned with the method of transesterification, esterification and esterification transesterification (both in one step and in two steps) in the production of biofuels.

• 1) durch die Anwendung von elektromagnetischer Mikrowellen-MW(Microwave) oder RF Radiofrequenzenergie
• 2) der Prozess wird so geleitet, dass die Reaktanten im Kontakt mit dem heterogenen Katalysator eine ausreichend hohe Bewegungsgeschwindigkeit erreichen
• 3) durch das Emulgieren der Komponenten des Reaktanten mit dem homogenen Katalysator
• 4) durch die Erhaltung der Reaktion bei dem partiellen Druck oder über dem partiellen Druck der verdampften Komponenten der Reaktanten

The process can be intensified in one or more ways:

• 1) by the use of electromagnetic microwave MW (Microwave) or RF radio frequency energy
• 2) the process is conducted so that the reactants in contact with the heterogeneous catalyst reach a sufficiently high rate of movement
• 3) by emulsifying the components of the reactant with the homogeneous catalyst
• 4) by maintaining the reaction at the partial pressure or above the partial pressure of the vaporized components of the reactants

By the application of one or more of the listed steps the reaction rate can be increased. As well may have higher conversion (higher alkyl ester yield) or both can be achieved.

patent US 6884900 B2

One of the patents seeking a method of increasing the rate of transesterification is the patent. US 6884900 B2 Maeda, Yasuaki (Kawachinagano, JP) and others (Method for producing fatty acid alcohol esters), in which in the usual method of transesterification of triglycerides in alkyl esters additionally the effect of ultrasonic energy in the frequency range of 15 to 100 kHz at an intensity from 0.5 to 20 W / cm ² in the presence of a homogeneous catalyst is used. Another frequency range of 200 to 3000 kHz at the intensity of 0.5 to 20 W / cm ² to shorten the sedimentation time for the separation of glycerol and alkyl ester.

The increased consumption of biofuels, the ever-increasing demand force the manufacturers of alkyl esters to intensify the production facilities. This can either be achieved by building new production facilities of greater capacity, or all the suggestions in the patents to improve the process of transesterification, especially to increase the reaction rate, can be used, whereby the amount of alkyl ester produced can also be reduced the existing one Production equipment can be increased.

a such significant contribution can be made by the methods which are the subject of this invention.

The Deficiencies of previous methods of production of fatty acid alkyl esters be through the solution according to this Invention eliminated for the most part. The main change The new process is based on the fact that the process of esterification and transesterification using a new component as defined in the claims of the subject patent and precisely demarcated, and co-emulsifier was named.

At the Studying, researching, and observing kinetics, the transformation reactions to obtain fatty acid alkyl esters We have found that there is another way to look at it Advantageously, the reaction rate of these systems under increased relatively advantageous and simple conditions can be.

If we use the work of Freedman ( Freedman JAOS, vol. 61 October 84 ), we can quote that the conversion of triglycerides under the conditions of mechanical mixing, at a temperature of 60-63 ° C, in the molar ratio of alcohol to triglyceride of 6: 1, a dose of 0.5% sodium methoxide in 60 minutes reaches a level of 98%, where the equilibrium (equilibrium) between the input reactants and the end products of the reaction stabilizes.

Abb. 3 Allgemeine Darstellung der Transesterifikationsreaktion von pflanzlichem Öl bei der Methanolyse

Fig. 3 General presentation of the transesterification reaction of vegetable oil in methanolysis

Abb. 4 Darstellung der Zusammensetzung der Produkte der Transesterifikationsreaktion nach der ersten Reaktionsstufe This is the stoichiometric equation as the final representation of the result of transesterification. The course of the reaction, however, is gradual: 1st stage:

Fig. 4 Representation of the composition of the products of the transesterification reaction after the first reaction stage

Abb. 5 Darstellung der Zusammensetzung der Produkte der Transesterifikationsreaktion nach der zweiten Reaktionsstufe 2nd stage:

Fig. 5 Representation of the composition of the products of the transesterification reaction after the second reaction stage

Abb. 6 Darstellung der Zusammensetzung der Reaktionsendprodukte 3rd stage:

Fig. 6 Representation of the composition of the reaction end products

This is the final stoichiometric composition of the products the transesterification, if we have the formation of by-products (unreacted alcohol, resulting soap, etc.) do not take into account.

For our consideration is important to note that at the transesterification stepwise intermediates arise.

In the first stage produces diazylglyceride, in the second stage monoazylglyceride. Only in the third stage does the stoichiometric final composition become 1 mol glyceride and 3 mol methyl ester, so the 100% conversion reached.

Around to reach the stoichiometric final yield such conditions are created that the reaction in the direction the origin of the products on the right side of the stoichiometric equation expires.

• • Erhöhung des Alkoholüberschusses, das stöchiometrische Verhältnis Alkohol zu Triglyzerid 3:1 steigt in kommerziellen Herstellungsanlagen auf den Wert 6:1 und auch höher
• • Erhöhung der Temperatur der Komponenten der Reaktanten auf einen Wert nahe dem Siedepunkt des Alkohols oder über den Siedepunkt des Alkohols bei Temperaturen von 70°C bei einem Druck von ca. 0.5 10⁵ Pa bis 7·10⁵ Pa, manchmal auch mehr in Technologien mit einem heterogenen Katalysator, in der Regel in Durchflussanlagen, in Druckreaktoren
• • Erhöhung der Mischintensität der Komponenten, die miteinander reagieren sollen, durch verschiedene Konstruktionsvorschläge für Mischanlagen, wo bei größerer Turbulenz ein besserer Kontakt der Reaktionskomponenten erreicht wird Andererseits kann aber die übermäßige Steigerung der dynamischen Turbulenz Schwierigkeiten bei der Abscheidung des Alkylesters vom Glyzerin verursachen, wenn schwer trennbare Emulsionen entstehen, wodurch ein Zustand der verschlechterten Separierung hervorgerufen wird (bis zu einigen Stunden), eventuell kann sich dieser Zustand im Beisein der entstehenden Seifen verschlechtern, wobei außerdem verschiedene Arten von Zentrifugen eingesetzt werden müssen, was wiederum sowohl die Investitionsals auch die Betriebskosten (Herstellungskosten) erhöht.

It is known that a higher conversion, close to the stoichiometric, can be achieved by suitable reaction conditions, such as:

• • Increasing the excess alcohol, the stoichiometric ratio of alcohol to triglyceride 3: 1 increases in commercial production plants to the value 6: 1 and higher
• • Increasing the temperature of the components of the reactants to a value near the boiling point of the alcohol or the boiling point of the alcohol at temperatures of 70 ° C at a pressure of about 0.5 10 ⁵ Pa to 7 · 10 ⁵ Pa, sometimes even more in technology with a heterogeneous catalyst, usually in flow systems, in pressure reactors
• • Increasing the mixing intensity of the components that are to react with each other, through different design proposals for mixing plants, where better contact of the reaction components is achieved with greater turbulence. On the other hand, the excessive increase in dynamic turbulence can cause difficulty in depositing the alkyl ester from the glycerin, if difficult separable emulsions are formed, causing a state of deteriorated separation (up to a few hours), possibly in the presence of the resulting soaps, and in addition, various types of centrifuges must be used, which in turn reduces both investment and operating costs ( Production costs) increased.

With the measures described above, a higher conversion is expected, but it can not be limited, in what time, that is, in which reaction time From this, the question arises, on wel It is possible to achieve a shortening of the reaction time, which ultimately has an effect on the production capacity of the plant.

If the reaction time will be short if such a solution finds, then the production capacity of the current existing production plants are increased. If a Such solution does not find the manufacturers of alkyl esters be forced by the rising demand for fuels new production facilities with larger capacities to build.

The Answer may be that if a shorter reaction time achieved at the same time as the speed of the reaction increases.

• • Erhöhung der Reaktionsgeschwindigkeit auf das bis zu 15-fache bei Verwendung von Co-Lösungsmitteln (zyklische Äther) oder in einem Zusatz von Alkoholüberschuss im Molverhältnis 15:1 bis 30:1 Alkohol zum Triglyzerid und mit einem weiteren Zusatz einer geringeren Menge von zyklischem Äther
• • Erhöhung der Reaktionsgeschwindigkeit durch Verwendung eines Zusatzstoffes, welcher mit einer bis zu 30%-igen Überschussmenge bezogen auf das Finalprodukt Alkylester zu Beginn der Transesterifikations- oder der Esterifikationsreaktion eingebracht wird
• • Erhöhung des gegenseitigen Kontaktes der Reaktanten durch die Schaffung nacheinander angeordneter Reaktionszonen, Erhöhung der Turbulenzen (Reynolds-Zahl mindestens 2100 bis 4000)
• • Erhöhung der Reaktionstemperatur nicht mehr als 215°C, Erhöhung der Turbulenzen Reynolds-Zahl nicht weniger als 4000, Erhöhung des Alkoholüberschusses 8 bis 42%
• • Erhöhung des Transformationsablaufes für die Herstellung von Alkylesterm. Erhöhung der Reaktionsgeschwindigkeit und gleichzeitige Steigerung der Konversion (eine größere Alkylesterausbeute) durch das Einwirken von Mikrowellen oder elektromagnetischer Radiofrequenzenergie oder durch das Einwirken von Ultraschallenergie unter Verwendung eines homogenen Katalysators

The effort to increase the speed of the transformation reactions was cited in the cited patents in the previous part. These were:

• Increasing the reaction rate up to 15-fold when using cosolvents (cyclic ether) or in an addition of excess alcohol in the molar ratio 15: 1 to 30: 1 alcohol to the triglyceride and with a further addition of a smaller amount of cyclic ether
• Increasing the reaction rate by using an additive which is introduced at an up to 30% excess amount based on the final product alkyl ester at the beginning of the transesterification or the esterification reaction
• • Increasing the mutual contact of the reactants by creating successively arranged reaction zones, increasing the turbulence (Reynolds number at least 2100 to 4000)
• • Increase of the reaction temperature not higher than 215 ° C, increase of the turbulence Reynolds number not less than 4000, increase of the alcohol surplus 8 to 42%
• • Increasing the transformation process for the preparation of alkyl esters. Increasing the reaction rate and simultaneously increasing the conversion (a larger alkyl ester yield) by the action of microwaves or radio frequency electromagnetic energy or by the application of ultrasonic energy using a homogeneous catalyst

The Advantages and also the shortcomings of these patent solutions were commented in the previous part of the patent.

The Measures referred to and discussed herein are to be adopted in accordance with well-known findings from this field so the Improve conditions for the process of transesterification and the esterification for the production of fatty acid alkyl esters to lead.

Let's go back to the already mentioned stoichiometric equation 3 . 4 . 5 . 6 and consider this reaction from the point of view of the findings of colloid chemistry. Already at first glance we can conclude that diazylglycerides and monoacylglycerides are intermediates of the transesterification reaction and form the stepwise reaction both in the first and in the second stage, and form a mixture with the input raw materials and the reaction products.

There Monoazyl glycerides and diazyl glycerides in a broad spectrum as emulsifiers in the food industry, in cosmetics and used in other areas, we ask ourselves the question in which way they also influence the transesterification reaction can.

The answer we are looking for z. In the table below. Value HLB of the emulsifier Property of the emulsifier 1-3 foam separator 2-6 Emulsifier type V / O (water in oil) 7-8 Wetting agent 8-18 Emulsifier type O / V (oil in water) 13-15 Detergents 15-20 solubilizers

The ability of an emulsifier to form emulsions of a particular type is given by its solubility in disperse environment and may be from its HLB value (hydrophilic-lipophilic balance) be be true. It is a dimensionless number and surfactants (emulsifiers) are assigned the value 0 to 20.

The Monoazyl glycerides and diazyl glycerides are HLB 4-6 assigned, so we evaluate them as emulsifiers, which the emergence of emulsions of the type V / O (water in oil) prefer.

Out From this point of view, it can be assumed that the presence of Diazylglyceriden and monoazylglycerides in the reaction mixture of Reactants and products of the transesterification reaction the emergence of a system in which in the external environment Reaction components are retained which have oleofilen character, and in the inner phase components arise that have a hydrofile character to have.

In the outer phase will become triglycerides, Monoazylglycerides, diazylglycerides and in the inner phase alcohol and glycerin are.

The Reactants and the products in the created system are going through Transesterification show a tendency from the point of view of Stoichiometry on the left side of the stoichiometric To remain equation.

Generally applies in chemistry, that if the yield of the reaction products and to increase the reaction rate, the reaction and their course towards the emerging products, so on shifted the right side of the stoichiometric equation must become.

We have found that such a shift can be done so that the emergence of a system of the type O / V (oil in water) is preferred. This can be achieved so that the HLB value of the system in which the transesterification takes place, is increased, so by the addition of a component with a higher HLB value.

We have established and experimentally confirmed by many experiments that the reaction rate of transesterification at the production of fatty acid alkyl esters by the addition a co-emulsifier whose HLB value is greater than 9 is considerably increased.

Also in observation, and in the study of esterification reactions the conversion of carboxyl fatty acids into alkyl esters we found similar dependencies.

Abb. 7 Allgemeine Darstellung der Esterifikationsreaktion

Fig. 7 General description of the esterification reaction

Of the Addition of a co-emulsifier with a suitable HLB value shifts the reaction towards the resulting product increases So the reaction rate of the esterification.

Proportional the reaction rate drops to the formation of water of reaction, and therefore agents are added which bind the water. Such Means are anhydrides of acids, chlorates of acids, Metaphosphoric acid, metal oxides and various sorbents.

We have found that also the co-emulsifier declared in this patent can be counted to these funds.

The Effect of co-emulsifier in the process of transesterification of Triglycerides or carboxylic acids can also be found among others Viewpoints.

• – kommen die Reaktanten auch bei mäßigeren Reaktionsbedingungen gegenseitig in Kontakt, z. B. bei niederen Temperaturen, geringerem Anspruch an intensives Mischen.
• – werden infolge dieser vorteilhaften Bedingungen die Monoazylglyzeride und die Diazylglyzeride an der Phasengrenze die Tendenz aufweisen, als diphile Moleküle dorthin zu streben, wo sich der Co-Emulgator in der Lösung aus Alkohol und homogenem Katalysator befindet, was den Verlauf der katalysierten Reaktion bedeutend beschleunigt. Die Reaktionszeit für die Erreichung einer hohen Konversion und die Schaffung des Finalproduktes Alkylester mit einem Normgehalt nichtreagierter Nebenkomponenten, wie sie zum Beispiel von der Norm DIN EN 14214 festgelegt werden, verkürzt sich.

Prüfparameter Grenzwerte Einheit Estergehalt min 96,5 % Gehalt an freiem Glyzerin max 0,02 % Monoglyzerid-Gehalt max 0,8 % Diglyzerid-Gehalt max 0,2 % Triglyzerid-Gehalt max 0,2 % Gehalt an Gesamtglyzerid max 0,25 % Tab-2 Einige Qualitätsparameter laut Norm DIN EN 14214

• • machen sich auch spezifische Interaktionen von Komponenten der Dispersion der Reaktanten mit dem Co-Emulgator beim Kontakt mit dem heterogenen Katalysator positiv bemerkbar. In der technologischen Praxis werden bei Rektionen mit heterogenen Katalysatoren die Kontakte mit den aktiven Zentren des Katalysators für sehr wichtig gehalten. Wenn eine bessere Benetzung der aktiven Oberfläche des Katalysators mit Reaktanten erreicht werden kann, bedeutet dies immer einen größeren katalytischen Wirkungsgrad in der gegebenen Reaktion.
• • Sind der Co-Emulgator, sein Typ und weitere Parameter in den Patentansprüchen definiert. Außer dieser Spezifizierung muss betont werden, dass er als Produkt ausgewählt wurde, das in basischer und sauerer Umgebung stabil ist. Bei Transesterifikations- und Esterifikationsreaktionen reagiert er nicht chemisch, verbleibt im Reaktionssystem, und da er mit einem höheren HLB-Wert ausgewählt wurde, verbleibt er nach Ablauf der Reaktion vorzugsweise in einer polaren Umgebung, also in der Glyzerinphase, oder bei Esterifikationsreaktionen in der Phase Wasser-Alkohol.
• • Bleibt er nach der Regenerierung, der Verdampfung des Alkohols aus der Wasser-Alkohol-Phase, im saueren Wasser, wenn ein homogener Katalysator verwendet wurde, und kann an den Beginn der Esterifikationsreaktion zurückkehren.
• • Spielt der Rest-Co-Emulgator, der nach der Beendigung der Transesterifikationsreaktion in der Glyzerinphase verbleibt, eine sehr wichtige Rolle. Seine Wirkung wird dadurch sichtbar, dass er in bedeutendem Maße die Sedimentierung (schnelle Abscheidung) der Glyzerinphase vom Alkylester beschleunigt. Die Abscheidungswirkung wird enorm erhöht, die Phasenteilung der Produkte erfolgt in einigen Minuten, nicht in einigen Stunden (wie dies bei einigen älteren kommerziellen Technologien der Fall ist).

In the created system of reactants, the trans-esterification of the co-emulsifier causes, even at low concentration, a decrease in the interfacial tension at the phase boundary of the dispersion between the reactants. Thereby:

• - The reactants come into contact even under more moderate reaction conditions, for. B. at low temperatures, lower demand for intensive mixing.
• As a result of these advantageous conditions, the monoazyl glycerides and the diazyl glycerides on the Phase boundary tend to aspire as diphilic molecules to where the co-emulsifier is in the solution of alcohol and homogeneous catalyst, which significantly accelerates the course of the catalyzed reaction. The reaction time to achieve a high conversion and the creation of the final product alkyl esters with a standard content of unreacted secondary components, as for example from Standard DIN EN 14214 be fixed, shortened.

Test parameters limits unit Estergehalt min 96.5 % Content of free glycerin max 0.02 % Monoglyceride content max 0.8 % Diglyceride content max 0.2 % Triglyceride content max 0.2 % Content of total glyceride max 0.25 % Tab-2 Some quality parameters according to standard DIN EN 14214

• • Also, specific interactions of components of the dispersion of the reactants with the co-emulsifier on contact with the heterogeneous catalyst are positively noticeable. In technological practice, in reactions with heterogeneous catalysts, the contacts with the active sites of the catalyst are considered to be very important. If better wetting of the active surface of the catalyst with reactants can be achieved, this always means greater catalytic efficiency in the given reaction.
• • Are the co-emulsifier, its type and other parameters defined in the claims. Besides this specification, it must be emphasized that it has been selected as a product that is stable in basic and acidic environments. In transesterification and esterification reactions, it does not react chemically, remains in the reaction system, and since it has been selected with a higher HLB value, it preferably remains in a polar environment, ie in the glycerol phase, or in esterification reactions in the phase of water after the reaction has ended -Alcohol.
• • Remains after regeneration, evaporation of the alcohol from the water-alcohol phase, in the acidic water when a homogeneous catalyst is used, and can return to the beginning of the esterification reaction.
• • The residual co-emulsifier, which remains in the glycerol phase after completion of the transesterification reaction, plays a very important role. Its action is evident in that it significantly accelerates the sedimentation (rapid separation) of the glycerol phase from the alkyl ester. The deposition effect is enormously increased, the phase sharing of the products takes place in a few minutes, not in a few hours (as is the case with some older commercial technologies).

The Most processes in nature are at the phase boundary and is related to surface phenomena. For example, biological enzyme processes become technologies understood, adsorption processes, the formation of dispersions, wetting operations and many others, according to the laws expire that apply to surface phenomena. That's exactly how we can do the transesterification reactions consider the production of alkyl esters. Already at the beginning of Process must have a dispersion with two polarities of different and immiscible reactants (triglyceride - alcohol + homogeneous catalyst) for the reaction to start. in the During the reaction, intermediates (diazyl glycerides, Monoazylglyceride), which are typical emulsifiers in the original disperse environment prefer the emergence of a type V / O emulsion (polar reactant + homogeneous catalyst in non-polar vegetable oil or animal fat). If suitable conditions exist, arise in Course of the reaction soaps (sodium or potassium soap, fatty acid compounds), which have a high HLB value and the emergence of an opposite Prefer O / V type emulsion (triglycerides, monoazyl glycerides, Diazyl glycerides in polar environment, alcohol + homogeneous catalyst).

By the fact that in the course of the reaction soaps arise, the act as accelerators of the transesterification reactions stabilized themselves in the plants for the production of alkyl esters certain standard reaction times according to which the manufacturing equipment were designed and built.

On the other hand, it is well known that the formation of soaps of fatty acids sometimes reduces the yield of the fatty acid alkyl esters by more than 1%, and also the deposition process of the Glycerin phase difficult. Longer deposition cycles were mostly solved by incorporating centrifuges into the manufacturing equipment.

Around larger yields of the required alkyl ester to try to create such conditions, prevent the formation of soaps. These are the ones in this area Well known measures that improve the quality of Input raw materials (limited content of free fatty acid, Water content and others), as well as technological measures for the water content in the homogeneous catalyst, in the recirculated Alcohol and more.

As a result These measures involved the reduction of soap formation and thus achieved higher yields, but on the other hand Emerged new problems in the quality of the produced Alkylesters, where stabilized under the conditions of the usual Cycle too high a content of mono- and diglycerides found has been. This fact means that the process of transesterification not finished.

As a result For this fact, solutions were sought, such as the reaction rate the transesterification can be increased at high yields can. Many solutions have been published in the above mentioned ones Patents.

at our solution is a method for the production of fatty acid alkyl esters according to this Inventions, but beyond the problems and shortage eliminate the transesterification process.

The individual parts were designed in such a way that answers and explanations of the mechanisms of reactions in the results of basic research were sought. There will be new insights, Applications of experience in colloid chemistry and a new one Perspective on the mechanism of transesterification discussed. From this we have derived a new, feasible procedure for the production of alkyl esters in a wide range of industrial applications developed on the basis of homogeneous and heterogeneous catalysts.

The new knowledge of the advantageous use of the co-emulsifier, which have been worked up in the individual patent claims are systematic with the conditions of increased contact connected between the reactants, which are already known Use mixing methods that are beneficial to such manufacturing equipment can be used, where even further intensification the reaction rate is necessary.

Further explanations of the invention are in the 1 - 7 Refer to schematically illustrated embodiments.

1 shows the basic scheme of a continuous production plant for fatty acid alkyl esters.

2 shows that system for essay esterification, transesterification with U = ultrasonic energy. The program monitoring is done by observing the effect of the mixing intensity, the effect of the temperature influence and he impact of the ultrasonic energy.

3 shows the basic representation of the system of the laboratory flow system for esterification and transesterification. The program monitoring is done by observing the dependence of the flow rate on the efficiency, the influence of temperature and pressure, the effect of the ultrasonic energy and the effect of the microwave energy.

4 Figure 7 shows the flow scheme of the transesterification process of preparing fatty acid alkyl esters with a heterogeneous catalyst according to the claims of the invention.
R ₁ , R ₂ - reactors with the heterogeneous catalyst.

5 The flow chart of the esterification process shows the preparation of fatty acid alkyl esters with a homogeneous catalyst according to the claims of the invention.

6 The flow chart of the esterification process shows the production of fatty acid alkyl ester with a heterogeneous catalyst according to the claims of the invention.
R ₁ , R ₂ - reactors with the heterogeneous catalyst.

7 Figure 7 shows the flow scheme of the esterification and transesterification process of producing fatty acid alkyl esters with a heterogeneous catalyst according to the claims of the invention.
R ₁ - reactor with an acid catalyst
R ₂ , R _n - reactors with a basic heterogeneous catalyst.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - CA 2131654 [0013, 0014]
• US Pat. No. 6,712,867 B [0014, 0015]
• - US 2316141 [0014, 0015]
• - WO 2004085585 A1 [0015, 0016]
• US 20060293532 A1 [0015, 0016]
• US 2003/0032826 A1 [0016, 0017]
• US 2005/0108927 A1 [0019, 0020]
• WO 2006/002087 [0020, 0021]
• US 2005/0274065 A1 [0020, 0021]
• US 6884900 B2 [0023, 0024]

Cited non-patent literature

• - EN 14105 [0004]
• - EN 14103 [0004]
• H. Kreutzer, J. Am. Oil. chem. soc. 61 (1984) 343 [0008]
• - Freedman JAOS, vol. 61 October 84 [0029]
• - Standard DIN EN 14214 [0058]

Claims (36)

Process for the preparation of fatty acid alkyl esters and glycerol using the transesterification process, characterized in that it comprises: preparing the catalyst containing a basic component and alcohol, creating an activated catalyst in such a way that the Co Emulsifier in the prepared homogeneous catalyst dissolves - the mixing of the triglyceride with the activated catalyst - the course of the transesterification process either in a batch or in a flow reactor under the conditions of increased contact between the reactants Process for the preparation of fatty acid alkyl esters and glycerol using the transesterification process, characterized in that it comprises: - the Creation of an activated remedy in such a way that in Alcohol dissolves the co-emulsifier - the mixing triglycerides with the activated agent - the Transesterification process under the conditions of increased contact between the reactants in a flow reactor or in successively arranged flow reactors, the one contain heterogeneous transesterification catalyst Process for the preparation of fatty acid alkyl esters using the esterification process, characterized that it comprises: - the creation of an activated By means of such a way that in the alcohol the co-emulsifier dissolves - the Mixing of the activated agent with the homogeneous acidic catalyst to create the activated catalyst - the mixing the carboxylic acids with the activated catalyst - the Expiration of the esterification process either in a tower or in a flow-through reactor under the conditions of increased Contact between the reactants Process for the preparation of fatty acid alkyl esters using the esterification process, characterized that it includes the following: - the creation of a activated agent in such a way that in alcohol the co-emulsifier dissolves - The mixing of the carboxylic acids with the activated means - the process of the esterification process under the conditions of increased contact between the Reactants in a flow reactor or arranged in succession Flow-through reactors containing a heterogeneous esterification catalyst contain Process for the preparation of fatty acid alkyl esters using the esterification process, characterized that it comprises: - the creation of an activated By means of such a way that in the alcohol the co-emulsifier dissolves - the Sequence of the esterification process in the way that the activating agent mixed with the triglyceride which also contains free carboxylic acids contains and participates in the process of esterification, under the conditions of increased contact between the reactants in a flow reactor or in successively arranged flow reactors, which contain a heterogeneous esterification catalyst, and - the Sequence of the transesterification process in such a way that the activator the triglyceride is mixed, which converted Alkyl esters of fatty acids from the previous stage contains and participates in the transesterification process, under the conditions of increased contact between the reactants in a flow reactor or in successively arranged flow reactors, which contain a heterogeneous transesterification catalyst Process according to the claims 1, 2, 3, 4 and 5, characterized in that the increase the contact between the reactants by creating a turbulent flow or by mixing under conditions, where turbulence is generated by the action of ultrasonic energy, Microwave energy, electromagnetic radio frequency energy or achieved by their mutual combination. Process according to claim 6, characterized characterized in that mixing under the conditions of turbulent Flow characterized by the value of the Reynolds constant is greater than 1500. A method according to claim 6, characterized in that the action of the ultrasonic energy takes place at a frequency of 10 to 250 kHz at an intensity of 0.3 to 25 W / cm ² . Process according to claim 6, characterized characterized in that the action of the microwave energy or the electromagnetic radio frequency energy at a frequency of 1 MHz to 100 GHz. Process according to the claims 1, 2, 3, 4 and 5, characterized in that the co-emulsifier a nonionic surfactant is (surfactant). A method according to claim 10, characterized characterized in that the co-emulsifier consists of a group of surfactants is selected, the alkyl polyglycol ether, alkylaryl polyglycol ether, Azylpolyglycol ethers, acylated and alkylated alkanolaminopolyglycol ethers, Block copolymers of ethylene oxide with propylene oxide, esters and ethers of polyalcohols or other groups of nonionic Contains surfactants, or that the co-emulsifier from their mixtures was selected. A method according to claim 10 and 11, characterized in that the co-emulsifier has an HLB value has more than 8. Process according to the claims 1, 2, 3, 4 and 5, characterized in that the process at a Pressure takes place, which is less than the partial pressure of Components of the reactants. A method according to claim 13, characterized characterized in that the process takes place at a pressure, the is higher than the partial pressure of the components of the reactants. A method according to claim 14, characterized in that the process takes place in a pressure interval of 0.5 · 10 ⁵ Pa to 7 · 10 ⁵ Pa. Process according to the claims 1, 2, 3, 4 and 5, characterized in that the alcohol is methanol or ethanol or a mixture of both. Process according to the claims 1, 2 and 5, characterized in that the triglyceride vegetable oil or animal fat or their mixture. A method according to claim 17, characterized characterized in that the vegetable oil or the animal fat or her Mixture of common food used frying oils and fats of industrial food products or by-products the soap industry or revised municipal waste of plant or animal origin. A process according to claims 3, 4 and 5, characterized in that the carboxylic acids are higher fatty acids having a carbon number greater than C _8, usually in the range of C ₁₂ to C ₁₈ , derived from vegetable oils or animal fats, or as free fatty acids in the Triglycerides are included. Process according to the claims 1, 2 and 5, characterized in that the transesterification process catalyzed by a basic catalyst. A method according to claim 20, characterized characterized in that the homogeneous basic catalyst from the group sodium hydroxide, potassium hydroxide, sodium methoxide or ethanolate, Potassium methoxide or ethanolate, titanium methoxide or ethanolate or tin oxide, magnesium oxide or zinc oxide. A method according to claim 20, characterized characterized in that the heterogeneous catalyst is a solid catalyst of the type active component anchored on a support. A method according to claim 22, characterized characterized in that the active component of the catalyst the group of hydroxides, silicates and carbonates of alkaline metals or metals of alkaline rock, from the group of silicon oxides, the magnesium oxides selected from tin, zinc and titanium oxides, or that the active component of the catalyst is a combination this is active components. A method according to claim 22, characterized in that the catalyst is from the group of interchangeable Resins (ion exchangers) selected in active hydroxide form is. Process according to the claims 3, 4 and 5, characterized in that the Esteriflkationsprozess catalyzed by an acidic catalyst. A method according to claim 25, characterized characterized in that the homogeneous catalyst is selected from the group of Mineral acids such as hydrochloric acid, sulfuric acid, Phosphoric acid, from the group of organic acids such as arylsulfonic, alkylarylsulfonic and chloroacetic acid or that the homogeneous catalyst is a combination of these Acids is. A method according to claim 25, characterized characterized in that the heterogeneous catalyst is a solid catalyst of the type active component anchored on a support. A method according to claim 27, characterized characterized in that the active component of the catalyst the group of mineral acids, the Lewis acids, from the group of oxides and ions of the metals of silicon, aluminum, Titanium, silver or selected from the group of superacids or that the active component of the catalyst is a combination this is active components. A method according to claim 25, characterized characterized in that the catalyst is selected from the group of internal Resins (ion exchangers) in active acid form or zeolites is selected in active acidic form. Process according to the claims 1, 2 and 5, characterized in that the ratio from alcohol to triglyceride in the molar ratio 3: 1, or that the molar ratio of alcohol to triglyceride is higher than the stoichiometric. Process according to the claims 3, 4 and 5, characterized in that the ratio from alcohol to the carboxylic acids in the molar ratio 1: 1, or that the molar ratio of alcohol to the Carboxylic acids higher than the stoichiometric is. Process according to the claims 1 and 3, characterized in that the homogeneous catalyst in in an amount of 0.2 to 2% added to the mass of the triglyceride becomes. Process according to the claims 2, 4 and 5, characterized in that the heterogeneous catalyst is in the reactor, and that the filling in the reactor 3 represents up to 85% of the internal volume of the reactor or reactors. Process according to the claims 1, 2, 3, 4 and 5, characterized in that the co-emulsifier in in an amount of 0.05 to 2% of the mass of the triglyceride or the Carboxylic acid is added. Process according to the claims 1, 2 and 5, characterized in that the way of producing the Fatty acid alkyl esters and glycerine in addition includes: - the deposition of the fatty acid alkyl ester from the glycerol phase - the regeneration of the unreacted Alcohol from the products of the transesterification reaction (from the Alkylester and the Glyzerinphase) by the evaporation with diminished print - the purification of the fatty acid alkyl ester through a process involving neutralization, extraction polar impurities due to water or the removal of polar impurities on a sorbent and drying. Process according to the claims 3, 4 and 5, characterized in that the way of producing the Fatty acid alkyl ester additionally comprises: - the Separation of the water-alcohol reaction phase from the fatty acid alkyl ester - the Regeneration of unreacted alcohol from the products of Esterification reaction by evaporation at reduced pressure - the Purification of the fatty acid alkyl ester by a process which involves neutralization, the extraction of polar impurities by water or the removal of polar impurities on one Sorbent and drying.