KR20110012041A - Method for production of hydrotreated bio diesel - Google Patents

Abstract

PURPOSE: A method for production of a hydro-treated bio diesel is provided to remarkably improve the processing efficiency by recycling biomass for which hydrogenation is treated. CONSTITUTION: A method for production of a hydro-treated bio diesel comprises the steps of: hydrolyzing biomass by using catalysts; performing a hydrogenation process for the hydrolyzed biomass in first and second hydrolyzing reactors(2a,2b); and recycling the biomass into the previous processing step.

Description

Production method of biodiesel {METHOD FOR PRODUCTION OF HYDROTREATED BIO DIESEL}

The present invention relates to a method for producing biodiesel by converting biomass, and more particularly, to a method for producing biodiesel comprising a hydroprocessing step.

As high oil prices continue, the development of alternative energy resources and the need for reduction of greenhouse gases has emerged globally, leading to the development of bioenergy resources. Furthermore, as the supply of biodiesel at home and abroad increased due to taxation and legislation worldwide, the bioenergy market is growing at an annual rate of 8-12%.

Representative technology for producing diesel oil from biomass is a technique for producing Fatty Acid Methyl Ester (FAME). In addition to the advantages of alternative energy obtained from biomass, FAME has the advantage of higher cetane number compared to diesel oil obtained from conventional mineral oils in terms of physical properties, but has a disadvantage of low oxidation stability and high manufacturing cost.

Presented as the next generation technology is HBD (Hydrotreated biodiesel) prepared by directly hydrogenating triglycerides through a hydrogenation reaction. The production cost of HBD is higher than that of diesel obtained from mineral oil, but the oxidation stability is relatively high because of the hydrogenation process compared to the conventional FAME.

In addition, the cetane number has the advantage of producing high-quality diesel oil close to 100. In addition, in terms of energy efficiency and greenhouse gas reduction, HBD fuel has the most advantages over mineral oil and FAME.

There are two main processes of manufacturing HBD. One is a process consisting of only a hydrotreating process, and the other is a process in which an isomerization process is attached to a rear end of the hydrogenation process.

Hydro-treating in HBD is used to hydrogenate fat or fatty acid through hydrogenation reaction, and similar terms are used by mixing hydrogenation, deoxygenation (deoxidation), hydrodeoxygenation, decarboxylation and decarbonylation. Decarboxylation and decarbonylation are used interchangeably with hydrogenation reactions in the production of HBD because hydrogenation occurs when one of the carbon in the feed fat or fatty acid escapes.

In general, the vegetable oil used as a feed for producing biodiesel is composed of triglycerides. Hydrogenation of this ester form of triglycerides yields C15-C18 paraffinic materials, which can be used as biodiesel as the boiling point of these materials falls within the diesel range.

Conventional processes for hydroprocessing triglycerides have rapid reaction rates. As a result, instantaneous high exotherm occurs, which greatly shortens the life of the catalyst and causes a problem of stability of the process. In addition, there are many problems, such as the need for hydrogen consumption above the hydrocracking process level.

There are literatures that disclose existing HBD manufacturing techniques, and US 4,992,605 describes a process for producing biodiesel using CoMo, NiMo, or transition metals as a feedstock of crude palm oil as a conventional commercial hydrotreating catalyst. Is starting.

US 2007/0175795 discloses a process for directly hydrotreating triglycerides.

US 7,232,935 discloses a catalytic process for producing HBD using a vegetable oil as a feed followed by an isomerization step after the hydrogenation step.

US Pat. No. 7,279,018 discloses a patent for producing a product by mixing 0-20% of an antioxidant with isomerized HBD after hydrogenation.

US 2007/0010682 also includes a hydrotreating process and an isomerization process, wherein the feedstock comprises at least 5% by weight of free fatty acids and diluents, with a diluent: feedstock ratio of 5 It is limited to ˜30: 1.

As described above, a method of directly hydrogenating triglycerides is currently used as a collaborator for producing HBD, and this method requires high hydrogen consumption and has a problem of generating calorific value accordingly.

In order to overcome the above problems, the present invention further includes a step of recycling the hydrolyzed and hydrogenated biomass in a conventional HBD production process, far more than the hydrogen consumption required in the conventional HBD hydrogenation step. It is an object of the present invention to provide a new method of producing HBD which enables the same process to be carried out with a low amount of hydrogen consumption and which can control a high invention.

In order to achieve the above object, in one embodiment of the present invention, in the method for producing a biodiesel,

i) hydrolyzing the biomass using a catalyst;

ii) hydrotreating the hydrolyzed biomass; And

iii) recycling said hydrotreated biomass to at least one of steps i) and ii)

It provides a method for producing a biodiesel comprising a.

Further, in another embodiment of the present invention, step i) comprises at least two hydrolysis reactors, while one hydrolysis reactor hydrolyzes the biomass while the other hydrolysis reactor is step iii). It provides a method for producing a biodiesel, further comprising the step of washing the catalyst using a recycled hydrogenated biomass at.

In one embodiment of the invention, while the one hydrolysis reactor hydrolyzes the biomass, the other hydrolysis reactor washes the catalyst using the hydrotreated biomass recycled in step iii). It is characterized in that it is carried out repeatedly.

In another embodiment of the present invention, the biodiesel comprising the step of hydrothermal reaction of the product produced in step i) and the step of supplying hydrogen generated in the hydrothermal reaction to step ii) It provides a method of manufacturing.

By using the method according to the present invention, the process efficiency can be greatly improved, high stability can be ensured, the hydrogen consumption of the hydrotreating reaction can be reduced by about 30%, and the calorific value can be reduced by 50%.

In addition, by using two or more hydrolysis reactors alternately, it is possible to solve the problem that the intermediate product is adsorbed into the catalyst pores and thus the catalytic activity may be reduced.

The invention will be described in more detail with reference to the accompanying drawings, but the invention is not limited thereto.

The inventors found that one-third of the total hydrogen consumption is used in the conversion of triglycerides to fatty acids in the production process of HBD through direct hydrogenation of conventional triglycerides, and half of the total reaction temperature rise occurs. The present invention was thus completed based on the method of adding a hydrolysis step to the front end of the hydrotreatment step.

In figure 1 a schematic flow of the method according to the invention is shown.

First, the biomass 1 is introduced into the hydrolysis reaction step 2. The biomass introduced into the hydrolysis reactor here is hydrolyzed using a catalyst. Triglyceride of the biomass undergoes a hydrolysis reaction to form a first product containing fatty acid and glycerin. The biomass may be a biomass of vegetable oil, vegetable fat, animal fat, fish oil, recycled fat, vegetable fatty acid, animal fatty acid, or mixtures thereof. In addition, those used as catalysts in the hydrolysis reaction include solid acid catalysts. Here, the solid acid catalyst may be used in addition to silica alumina, zeolite, etc., but also a catalyst in which acid is enhanced by adding halogen such as fluorine and chlorine to aluminum oxide, but is not limited thereto.

Conventional hydrolysis processes require 30 to 50 kg / cm ² g of reaction conditions at about 250 ° C., thus consuming high energy. In addition, as fatty acids are produced at high temperature and high pressure, a process of highly corrosive material is required. However, in the present invention, by using a solid acid catalyst such as Resin, the hydrolysis step can be carried out under the conditions of 110 to 150 ℃ and atmospheric pressure.

In addition, in the hydrolysis reaction, the intermediate product may be adsorbed into the catalyst pores and interfere with the access of the reactants, thereby causing a problem of greatly lowering the catalytic activity.

In this case, in order to solve the deterioration of the catalyst activity, a regeneration process using methanol washing or burning the catalyst with air to recover the activity is required.

However, in one embodiment of the present invention, this problem can be easily solved by alternating operation using two or more hydrolysis reactors. That is, if two hydrolysis reactors are used, while the hydrolysis reaction of the biomass takes place in one hydrolysis reactor, the second one undergoes a hydrotreatment step (3) in the other hydrolysis reactor as described below. The product can maintain the activity of the catalyst by washing the catalyst.

According to an embodiment of the present invention, biomass is introduced into the first hydrolysis reactor 2a and hydrolyzed in the presence of a catalyst, and the resulting first product is sent to a hydrotreating step to be described below. When the intermediate product is stuck to the catalyst in the first hydrolysis reactor and the performance of the catalyst is lowered, the biomass introduced into the first hydrolysis reactor 2a is changed and the second hydrolysis reactor 2b is changed. The hydrolysis reaction takes place continuously.

In the first hydrolysis reactor in which the catalytic performance is reduced, the second product produced through the hydroprocessing step to be described below is recycled and introduced. The recycled second product serves to wash the intermediate reactant adhering to the catalyst of the first hydrolysis reactor 2a to restore catalyst activity. In addition, the recycled second product is sent to the hydroprocessing step together with the hydrolyzed first product in the second hydrolysis reactor 2b. As a result, the effect of diluting the fatty acid of the first product introduced into the hydrogenation step may be obtained.

After a certain time, when the activity of the catalyst of the second hydrolysis reactor 2b is lowered, the biomass-supplemented catalyst layer is introduced into the washed first hydrolysis reactor 2a, and the second hydrolysis reactor ( In 2b), the recycled second product may be introduced to wash the catalyst.

Alternating use of the hydrolysis reactor as described above may be controlled by observing the reactor differential pressure since the intermediate reactant is adsorbed onto the catalyst and the catalytic activity decreases when the differential pressure is steadily increased. The shift period may also be adjusted by time.

Thus, by using the hydrolysis reactor alternately and recycling the second product, there is an advantage that can not only solve the problem of lowering the catalytic activity but also continue the reaction continuously without interruption of the process, in the conventional method The additional process required could be eliminated.

The first product is subjected to a hydroprocessing step (3) after the hydrolysis step (2). The product comprising the fatty acid forms a second product comprising n-Paraffin.

The hydrotreating step of the present invention may include various methods. For example, in one embodiment, the hydrogenation step may be a gas-phase deoxygenation reaction, and in another embodiment, it may be a liquid-phase deoxygenation performed in a hydrocarbon solvent. . As the catalyst used in the hydrogenation step, palladium, precious metals such as platinum, and NiMo, CoMo, and the like may be used, and a metal phosphorus compound catalyst may be preferably used, but is not limited thereto.

Some of the second products produced in the hydroprocessing step may be recycled to any one or more of the hydrolysis step (2) and the hydroprocessing step (3).

As described above in the hydrolysis step, when the second product is recycled to the hydrolysis step 2, washing may be performed to prevent a decrease in catalyst performance. In addition, according to the recycle can not only increase the efficiency of the entire process but also has the advantage of ensuring high stability of the process.

When the second product is recycled to the hydrogenation step, it is possible to lower the exotherm of the hydrogenation reaction. In addition, by lowering the concentration of fatty acid which is a corrosive substance in biomass, it has the advantage of controlling the exposure of the material to severe corrosive environment.

In another embodiment of the present invention, the method may further comprise the step (4) of hydrothermal reaction by separating the glycerin in the first product produced in the hydrolysis step (2). The hydrothermal reaction takes place at about 270 ° C. to 320 ° C. Glycerin produced in the hydrolysis step undergoes a hydrothermal reaction to produce some hydrogen and lactic acid. Here, the generated hydrogen can be used to partially supplement the hydrogen required in the hydrogenation step.

According to the present invention, assuming that 1 mole of triglyceride introduced into the hydrolysis step is about 6 moles of hydrogen required in the hydrotreating step, and about 1 mole of hydrogen produced in the hydrothermal reaction of glycerin is required. A significant portion of the amount of hydrogen that can be obtained can be obtained from the hydrothermal reaction of the glycerin.

Through this reaction, it is possible to supplement the hydrogen required in the hydrogenation step, there is an advantage that can be produced in parallel with the high-value products of lactic acid.

On the other hand, the present invention is not limited to the described description, it will be apparent to those skilled in the art that various modifications and variations can be made without departing from the spirit and scope of the present invention. Therefore, such modifications or variations should also be seen as belonging to the claims of the present invention.

1 shows a schematic flow of the method of the invention.

※ Explanation of code of main part of drawing

1: biomass 2: hydrolysis reaction step

2a: first hydrolysis reactor 2b: second hydrolysis reactor

3: hydrotreatment stage 4: hydrothermal reaction stage

Claims (8)

In the method for producing biodiesel, i) hydrolyzing the biomass using a catalyst; ii) hydrotreating the hydrolyzed biomass; And iii) recycling said hydrotreated biomass to at least one of steps i) and ii) Method of manufacturing a biodiesel comprising a. The method of claim 1, wherein step i) comprises biodiesel, characterized in that at a temperature of 110 to 150 ℃. The method of claim 1, wherein step i) comprises using a solid acid catalyst. The method according to claim 1, wherein step i) comprises at least two hydrolysis reactors, while one hydrolysis reactor hydrolyzes the biomass, the other hydrolysis reactor is subjected to the recycled hydroprocessed in step iii). Washing the catalyst using biomass. The method of claim 4, wherein while the one hydrolysis reactor hydrolyzes the biomass, the other hydrolysis reactor washes the catalyst using the hydrotreated biomass recycled in step iii). Method for producing a biodiesel, characterized in that. The method of claim 1 or 5, further comprising the step of hydrothermal reaction of the product produced in step i) and supplying the hydrogen generated in the hydrothermal reaction to step ii) Way. The method of claim 6, further comprising the step of separately separating the latic acid produced in the hydrothermal reaction. The method of claim 6, wherein the hydrothermal reaction step is performed at 280 to 330 ° C.

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