RU2800416C1 - Method for producing biooil from fat acid with high acid numbers - Google Patents

Abstract

FIELD: biooil.

SUBSTANCE: method for producing biooil is described, which includes the following stages: esterification of a source of raw materials comprising glycerol and fatty acid is carried out to obtain biooil and water in a column-type reactor, which has a plurality of trays installed in it, forming a plurality of compartments in the vertical direction inside the reactor, whereas each of the plurality of trays has a hole formed in it, through which the vertically adjacent compartments communicate with each other, and the holes in adjacent plates are formed in a cross order, whereas the raw material source comprising glycerine and fatty acid are fed through respective material inlets located in the centre of the column reactor to carry out esterification on each tray of the reaction zone; the resulting bio-oil is removed through the bottom of the reactor; and the water generated by esterification is removed by evaporation, the generated water vapours are transferred to the distillation zone located at the top of the reactor, together with the effective ingredients, including the raw material source and the bio-oil, which turn into steam when evaporated, the steam is separated into water and effective ingredients including the raw material source and the bio-oil, and the effective ingredients are allowed to pass into the reaction zone, and the separated water is removed in a vapor state through the top of the reactor, whereas the bio-oil has an acid value of 30 mg KOH/g or lower, and the esterification reaction is carried out at a temperature of 170 to 350°C at atmospheric pressure without the use of a catalyst.

EFFECT: obtaining bio-oil from fat and oil with high acid numbers.

13 cl, 5 dwg, 4 tbl, 16 ex

Description

The field of technology to which the invention belongs

The present disclosure relates to a process for producing bio-oil from high acid number fat and oil, and more specifically, to a method for producing bio-oil applicable as heavy bio-oil and marine fuel bio-oil from high acid number fat and oil.

Prior Art

In Korea, a major project for the production of heavy bio-oil for power generation has recently been launched, and the demand for heavy bio-oil is steadily increasing. In addition, under the influence of IMO (International Maritime Organization) 2020, the demand for low sulfur fuel oil for marine applications is expected to explode, with increased attention being paid to marine biofuel oil in the form of low sulfur oil.

Heavy bio-oil for power generation is produced using fat and oil bio-resources such as animal and vegetable oils as raw materials, as well as by-products of biodiesel production, etc., and is an alternative fuel to heavy oil (bunker oil C). Currently, heavy bio-oil is used as a heavy oil-based fuel for power generators. A pilot project for the production of heavy biooil was launched in 2014, and after assessing the possibility of its implementation in 2019, the main project began to be implemented.

IMO 2020 is an annex to the International Convention for the Prevention of Pollution from Ships (MARPOL) adopted by the International Maritime Organization (IMO). On January 01, 2020, a new limit on the sulfur environment (sulfur content) in fuel oil used on ships came into force. Specifically, the maximum sulfur content of marine fuel oil has been reduced from 3.5% to 0.5%. Accordingly, there is an increasing demand for the use of low sulfur marine fuel oil as one of the measures to reduce sulfur oxide emissions. As such, bio-oil is inherently low in sulfur and as such, when burned in an internal combustion engine, produces less sulfur oxide than conventional coal-based oil.

Bio-heavy oil or bio marine fuel oil should be produced with an acid number below a certain level, as a high acid number can cause corrosion of internal devices and equipment. For this reason, feedstock sources for heavy biooil or marine biofuel oil must have a low acid number, and high acid number feedstocks can only be used after acid number reduction measures have been taken.

Various methods are known for reducing the high acid numbers of fats and oils. Methods for removing free fatty acids to lower the acid numbers of fat and oil as part of the overall refining process include removing free fatty acids by neutralization with an aqueous caustic solution and removing free fatty acids by distillation. However, the higher the acid number, the more free fatty acids are to be removed, making the removal of free fatty acids less economical. The aqueous alkali neutralization method has the problem that a large amount of waste water is generated. In order to use the free fatty acids contained in oil and fat with a high acid number without removing them, a process is proposed for converting free fatty acids into bio-oil.

An example is a process for producing bio-oil without removing free fatty acids from fat and oil with high acid numbers by reacting fatty acids with glycerol to produce bio-oil (glyceride). As used herein, the term "glyceride" is intended to encompass all mono-, di-, and triglycerides.

The production of bio-oil by the reaction of fatty acids with glycerol is known as one of the pre-treatment methods before using fatty acid-enriched oil (fat and oil with high acid numbers) as a diesel (FAME) biomaterial. Typically biodiesel (FAME) is produced by transesterification between bio-oil (glyceride) and methanol (MeOH). With a high content of fatty acids in the starting material, fatty acids cannot take part in transesterification, since fatty acids react with alkaline ingredients extracted from the reaction catalyst to form an increased amount of saponification ingredients (soap), resulting in a decrease in yield.

To solve this problem, a process has been proposed for the production of a biodiesel fatty acid alkyl ester (transesterification) in which the fatty acid and glycerol are first reacted under pretreatment conditions to form a glyceride, which is then re-reacted with methanol in the presence of a basic catalyst, as illustrated in the following. reaction scheme 1:

[Reaction Scheme 1]

In order to increase the reactivity of the process of converting fatty acid into bio-oil (glyceride), a catalyst is used or water generated as a reaction product during the reaction process is continuously removed.

US Patent Application No. 13/92435 discloses that the reaction is carried out in the presence of a solid catalyst. The reaction using a catalyst has the disadvantage of high production cost, not only because the catalyst is expensive, but also because the service life of the catalyst is shortened because it is poisoned by impurities or carbon deposits. In addition, water is removed in the form of vapour, in order to promote the smooth running of the reaction.

Fig. 1 is a schematic representation of a batch reactor commonly used for biooil production. As shown in FIG. 1, one reactor (1) is equipped with one stirrer (3). Although no reactants or products are fed into or removed from the reaction during the reaction, the batch reactor is designed to continuously remove the by-product, water resulting from the esterification, through the condenser (5).

Chinese Patent Nos. CN 2012-10580909 and CN 2018-10088660 propose a method in which the reaction without a catalyst is carried out under a low vacuum/reduced pressure or in a stream of nitrogen under atmospheric pressure, while water is carefully removed. Korean Patent No. 10-1073721 discloses a process in which the reaction is carried out in the presence of a catalyst under a low vacuum/reduced pressure or under a stream of nitrogen under atmospheric pressure while removing a by-product, water. As such, a batch reactor needs a device to easily remove by-product water in order to increase reactivity. The batch reaction process takes time to feed the raw material, withdraw the product, raise the temperature, etc., which has the disadvantage of lower output, higher production cost, and more labor than the continuous reaction process.

To solve the problem associated with periodic reaction processes, as well as to increase the volume of production and process yield, a continuous reaction process has been proposed. Fig. 2 is a schematic view of a continuously stirred reactor (CSTR). As shown in FIG. 2, the feedstock is pumped (2) into the reactor (6) while being heated by the heating device (4). The product formed in the reactor (6) is discharged from the bottom of the reactor while being cooled by the condenser (7). In addition, a by-product, water formed by the esterification reaction, is distilled off to the top of the reactor and can be removed using a condenser (8).

Since it is difficult to react the reactants in the order in which they are received in the CSTR reactor, it is difficult to achieve the goal of the reaction using only one reactor block. To compensate for this, some patents disclose the implementation of continuous reactions in a plurality of interconnected reactor blocks. To achieve the target level of reaction, Chinese Patent No. CN 2017-10598802 discloses a method in which reactions are carried out in four boiler-type reactor blocks connected in series, and US Patent Application No. 13/924235 discloses that continuous reactions are carried out in two reactor blocks. CSTR connected to each other. As such, when connected to each other, multiple CSTR stacks allow continuous reactions to be carried out at a higher reactivity than single CSTR stacks.

However, in the proposed batch reactors and CSTRs, there are losses of reactants and products along with the liberated water when side water is removed in the form of vapours.

According to the application for US patent No. 13/92435 water is removed in the form of vapors for a smooth reaction. However, since the vapor stream contains water, the feedstock and glycerol, there is even a decrease in yield. Thus, the raw material source and the glycerol must be separated from the vapor stream to be removed.

According to Korean Patent No. 10-1073721, by reacting 583.9 g of soap, 654.68 g of glyceride was isolated, and the total amount of distillation products is 58.58 g with about 3.5 ml of low molecular weight fatty acids contained therein. This indicates that fatty acids were lost in the form of vapors in an amount of about 0.5% of the mass. from the mentioned product, which is about 5.5% of the mass. from the total amount of distillation products.

In contrast to the column reactor, the stirred reactor (batch reactor, CSTR reactor) is designed in such a way that it is impossible to extract the reactant and product that are released in the form of vapors along with water during the removal of the by-product - water, with the loss as a result of the main substances during the reaction. Due to the inability to effectively remove water without loss of reactant and product, the reactor contains moisture from sources of raw materials. In addition, in a stirred reactor, it is not possible to fully process as reactants are received, so it is possible that a feedstock source does not take part in the reaction, but is released from the reactor. In contrast, the column reactor makes it possible to carry out the process as the reactants arrive, so that even a single reactor can guarantee sufficient reactivity.

[Prior Art Documents]

Patent document 1

US Patent Application 13/92435

Patent Document 2

Korean Patent No. 10-1073721

The essence of the invention

In some embodiments, the implementation of the present disclosure provides a method for the continuous production of biooil (glyceride) by reacting a fatty acid with glycerol without the use of a catalyst.

In other embodiments of the present disclosure, a process for producing biooil is provided that utilizes a column reactor to effectively remove the water by-product and make it unnecessary to purify the raw glycerin, whereby glycerol can be used as a source of raw materials, regardless of its content. moisture, and increase the yield of the reaction, while at the same time achieving economical production of bio-oil as a result.

According to the present disclosure, in some embodiments, a method for producing biooil is provided, comprising the following steps: esterification of a feedstock source containing glycerol and fatty acid is carried out to obtain biooil and water in a column-type reactor having a plurality of trays installed therein, forming a plurality of compartments in a vertical direction inside the reactor, wherein each of the plurality of trays has a hole formed in it, through which vertically adjacent compartments communicate with each other, and the holes in adjacent trays are formed in a cross order, while the raw material source containing glycerol and fatty acid is fed through respective material inlets located in the center of the column reactor for esterification on each plate of the reaction zone; remove the resulting bio-oil through the bottom of the reactor; and remove the water generated by esterification by evaporation, transfer the generated water vapor to the distillation zone located at the top of the reactor, together with the effective ingredients, including the raw material source and the bio-oil, which turn into steam when evaporated, separate the steam into water and effective ingredients including the raw material source and the bio-oil, and allow the effective ingredients to pass into the reaction zone, and the separated water to be removed in a vapor state through the top of the reactor, while the bio-oil has an acid value of 30 mg KOH/g or lower, and the esterification reaction is carried out at a temperature of 170 to 350°C at atmospheric pressure without the use of a catalyst.

The process for producing biooil from fat and oil with a high acid number according to an embodiment of the present disclosure is designed to produce biooil (glyceride) continuously by reacting a fatty acid and glycerol without using any catalyst in a column reactor constructed with the ability to effectively remove the by-product - water, which makes it unnecessary to purify the raw glycerin, as a result of which it is possible to use glycerol as a source of raw materials, regardless of the moisture content in it, and increase the reaction yield while simultaneously achieving economical production of biooil as a result of this.

Brief description of the drawings

Fig. 1 is a schematic representation of a batch reactor commonly used for biooil production.

Fig. 2 is a schematic view of a continuously stirred reactor (CSTR) typically used for biooil production.

Fig. 3 is a general schematic view of a column type reactor used for biooil production according to an embodiment of the present disclosure.

Fig. 4 is a schematic view of details of a column reactor according to an embodiment of the present disclosure.

Fig. 5 is a plot of acid numbers according to internal temperatures and retention times in a reactor according to an example of the present disclosure.

Detailed description

Embodiments of the present disclosure are illustrated to set forth the technical scope of the present disclosure. The scope of the claims corresponding to the present disclosure is not limited to the embodiments described below or the detailed descriptions of said embodiments.

All technical or scientific terms used herein have the meanings generally understood by one of ordinary skill in the art to which this disclosure pertains, unless otherwise indicated. The terms used in this document are chosen only to more clearly explain the present disclosure and are not intended to limit the scope of the claims in accordance with the present disclosure.

The expressions "include", "provided with", "have" and the like used in this document should be taken as non-limiting terms, meaning the possibility of including other embodiments, unless otherwise mentioned in the phrase or sentence that includes these expressions.

To understand the scope of this disclosure, it should be understood that the term "consisting of" and its derivatives, as used herein, are limiting terms that define the presence of the specified features, elements, components, groups, integers and / or stages, and also exclude the presence other unspecified features, elements, components, groups, integers and/or stages.

The singular expression may include plural values unless otherwise noted, and the same applies to the singular expression set forth in the claims.

As used herein, the term "about" is intended to include a manufacturing process acceptable range of error for a particular value, or a small numerical change in a particular value within the scope of the technical scope of this disclosure. For example, the term "about" means a range of ±10% of a given value, ±5% of a given value in one aspect, and ±2% of a given value in another aspect. For the scope of this disclosure, the specified level of approximation is reasonable unless a value is specifically indicated requiring a narrower range.

Below will be a detailed description of the present disclosure in conjunction with the accompanying drawings.

Fig. 3 is a general configuration diagram of a manufacturing device used in a biooil production method according to an embodiment of the present disclosure. As shown in FIG. 3, the reaction apparatus used in the present disclosure is a column type reactor having a plurality of trays installed therein, which form a plurality of compartments in the vertical direction within the reactor. The plurality of trays have corresponding holes formed therein through which vertically adjacent trays communicate with each other. Holes in adjacent plates are arranged in a cross order. The method for producing bio-oil according to the present disclosure includes the following steps: performing esterification of a raw material source (10') (hereinafter referred to as simply fatty acid if necessary) containing glycerol (10) and a fatty acid to obtain bio-oil (glyceride) and water by supplying source of raw material to the column reactor through respective material inlet channels located in the center of the column reactor to carry out esterification on each plate of the reaction zone (13b) located below the material inlet channels; removal of the resulting bio-oil (glyceride) through the lower part of the reactor; and removal of water generated by esterification by evaporation, transferring the resulting water vapor to the distillation zone located at the top of the reactor, together with effective ingredients, including a source of raw materials and bio-oil, which turn into steam during evaporation, separation of steam into water and effective ingredients (raw material source and bio-oil), allowing the effective ingredients to pass into the reaction zone and the separated water to be removed as a vapor through the top of the reactor. Bio-oil (glyceride) is formed by carrying out esterification at 170 to 350° C. for 2 hours or longer at atmospheric pressure without the use of a catalyst, and may have an acid number of 30 mg KOH/g or lower.

In the present disclosure, glycerin (10) includes purified glycerin and crude glycerin. More specifically, glycerin may have a concentration of 3 to 100 wt. -%, in particular, from 5 to 99 wt. -%, and more specifically, may include crude glycerol with a concentration in the range of 5 to 85 wt. and purified glycerin with a concentration in the range from 99 to 100% of the mass. In addition, crude glycerol produced in traditional fatty acid or biodiesel processes can be easily used without additional concentration, and a liquid state may be preferred.

In some specific embodiments, the implementation of the source of raw material (10'), including fatty acid, may have a fatty acid content in the range from 15 to 100% wt., and preferably from 20 to 97% of the mass.

Specifically, the raw material source comprising the fatty acid contains an acidic oil derived from soap processing. Soap is a soapy substance resulting from the reaction of a free fatty acid with an alkali added during the refining of vegetable oil. Soap is treated with sulfuric acid to make sour oil.

It is understood that the source of raw materials, including fatty acid, includes raw materials containing fatty acids, among the many products or by-products (for example, fatty acid resin) formed during the processing of oleochemical products. The term "oleochemical products" refers to vegetable and animal oils and fats or chemical products derived from them. The raw material source, including the fatty acid, may be a product or by-product formed during the production of oleochemical products, and preferably may be in the range of fatty acids content from 15 to 100 wt%.

In addition to this, the raw material source, including fatty acid, may additionally contain oil, which has fatty acid in its composition as a result of oil extraction and refining of vegetable/animal oils and fats (for example, palm oil sludge, palm oil production liquid waste , palm fatty acid distillate, etc.), the oil to be recovered (for example, edible oil waste, dark fat, etc.) and preferably can be vegetable and animal oil and fat with a fatty acid content of 15 to 100 wt%.

Before entering the reactor, the feedstock containing the fatty acid may be heated using the heater (12). In this regard, the temperature of the heater (12) may be from 100 to 250°C, and preferably from 150 to 250°C. The fatty acid may have an acid value greater than 30 mg KOH/g (high acid value) and may preferably be used in a liquid state. Once supplied, the heated feedstock can evenly maintain the temperature inside the reactor. The fatty acid can be heated prior to serving since its input is greater than the amount of glycerol.

The mixing ratio (molar ratio) of the raw material source comprising the fatty acid to glycerol refers to the molar ratio of the fatty acid contained in the raw material source to glycerol, and may range from 3:0.5 to 3:2, and preferably from 3: 0.75 to 3:1. When the amount of glycerol is less than the lower limit of the range of the mixing ratio (molar ratio), the desired acid number cannot be achieved. When the amount of glycerol exceeds the upper limit of the range of mixing ratio (molar ratio), unreacted excess glycerol remains in the final product. Specifically, in the case of supplying an excess of glycerol, the obtained bio-oil (glyceride) and glycerol are separated into different layers, which makes it necessary to carry out an additional glycerol separation process.

By the process for producing biooil according to the present disclosure, a high acid value oil and fat can be used to produce a low acid value biooil. As used herein, the term “high acid value oil and fat” refers to an oil and fat with an acid value greater than 30 mg KOH/g, greater than 40 mg KOH/g, greater than 50 mg KOH/g, greater than 60 mg KOH/g , more than 70 mg KOH/g, more than 80 mg KOH/g, more than 90 mg KOH/g, more than 100 mg KOH/g, more than 110 mg KOH/g, more than 120 mg KOH/g or more than 130 mg KOH/g, or, specifically, oil and fat having an acid value greater than 150 mg KOH/g, or 180 mg KOH/g.

According to an exemplary embodiment of the present disclosure, the biooil production process of the present disclosure used acid palm oil (PAO) with an acid value of 139 mg KOH/g or palm fatty acid distillate (DPFA) with an acid value of 189 mg KOH/g to produce bio oil. with an acid number of only 22 mg KOH/g or 26.2 mg KOH/g according to the retention time in the reactor.

Hereinafter, reaction conditions (formation) for producing bio-oil (glyceride) will be explained in detail. Prior to carrying out the reaction continuously in the column reactor, batch reaction conditions have been described, which is effective for optimizing the reaction conditions. Specifically, since the esterification according to the present disclosure is carried out in a high temperature range, a high reaction rate and a high fatty acid conversion can be achieved. The esterification is carried out at a temperature of from 170 to 350°C, and preferably from 200 to 250°C and atmospheric pressure. Even without the use of vacuum, a high reaction rate and a high degree of conversion are achieved. At a temperature outside the upper and lower limits of the reaction temperature range, the reaction rate and the conversion efficiency of the fatty acid are reduced, or the water generated by the esterification reaction between the fatty acid and glycerol is not easily removed, which may cause a reverse reaction.

The present disclosure is preferably carried out without any catalyst. In the presence of a catalyst, the reactivity can further increase. However, even if catalysts are not used, by-product water can be removed efficiently enough to increase reactivity. In the case of a catalytic reaction, the catalyst is difficult to recycle and expensive, thereby increasing the production cost. In addition, a catalyst removal process (eg, a filtration process) is additionally required. In other words, the absence of a catalyst results in the absence of catalyst removal processes, thus lowering the cost of production and enabling the economical production of biooil. In addition, the reaction is carried out for 2 hours or longer, or 2 hours 15 minutes or longer, and is considered to be completed within about 6 hours. In view of the foregoing, the reaction time, according to the present disclosure, can be from 2 to 6 hours.

Conversion is traditionally increased by applying vacuum/reduced pressure conditions or by passing a stream of nitrogen to facilitate the removal of water, a by-product of fatty acid esterification. The implementation of the process in such conditions requires the installation of equipment for operation in vacuum / under reduced pressure or for injection of nitrogen. However, since in the present disclosure the reaction is carried out at a rather high temperature of 170 to 350°C, and preferably 200 to 250°C, and atmospheric pressure, the water generated by the reaction is continuously removed from the reaction system without the use of additional equipment. Therefore, the esterification according to the present disclosure exhibits an excellent near-ideal conversion reaction rate beyond reaction equilibrium, even without the use of additional equipment.

The bio-oil (18) obtained in the present description includes mono-, di-, triglyceride, or a mixture thereof. The acid value of the bio-oil (glyceride), although different according to the intended use of the product, may be 30 mg KOH/g or less, and preferably 25 mg KOH/g or less.

Fig. 4 is a schematic view of details of a biooil column reactor according to the present disclosure. As shown in FIG. 4, the esterification reactor used in the present disclosure is a column type reactor that operates at atmospheric pressure. A plurality of trays (14a) are installed in the column reactor, which form a plurality of compartments in the vertical direction, each of the plurality of trays having an opening formed therein, through which vertically adjacent compartments communicate with each other, and the openings in adjacent trays are formed in a crosswise pattern. in order to allow the reagents to pass sequentially through the entire plurality of compartments.

The spaces inside the column reactor above and below the injection site of the feed source are respectively called the upper part (13a) and the lower part (13b), and the upper part is responsible for the distillation zone and the lower part for the reaction zone. The reaction zone is a space of a completely liquid type, completely filled with a liquid-phase source of raw materials and a bio-oil product. In such a column-type reactor, glycerol and fatty acid are fed through respective inlets located in the middle region of the reactor and flow down to the bottom to sequentially pass through various trays (14a) in the reaction zone (13b), while being continuously esterified, as a result whereby the rapid passage of the reactants can be prevented, and the reaction can be carried out in the order in which the reactants arrive to achieve a sufficient reaction time.

On each plate of the reaction zone, glycerol is esterified with a fatty acid to form bio-oil (glyceride) and water. The water (17) formed as a by-product evaporates at the high reaction temperature and travels in the vapor state through the steam channel (14b) formed on each tray, such as an orifice, valve or bubble cap, to the distillation zone (13b) at the top. column reactor. As the water evaporates and moves towards the distillation zone, which is the top of the reactor, the effective ingredients, including the raw material source and the bio-oil, rise with it in the upward flow. Thus, the water to be removed and the effective ingredients (feedstock source and bio-oil) to be retained coexist in vapor moving towards the top of the reactor.

The distillation zone at the top of the reactor is of the same design as the tray distillation column used for general chemical processes. As gas-liquid contact occurs on each plate in the distillation zone, the vapors leaving the reaction zone are separated into feedstock and bio-oil, which are in the liquid phase due to their high boiling point, and water in the gas phase, due to its low boiling point. The separated feedstock and bio-oil flow down the trays into the reaction zone at the bottom of the reactor, while water is released as vapor from the top of the reactor. In this regard, the water released in the form of vapors from the top of the reactor is cooled in the condenser. Some of the water is partly returned back to the reactor as a reflux and the rest is removed. The water and trace amounts of effective ingredients cooled in the condenser are subjected to reflux to improve the separation efficiency of water and effective ingredients (raw material source and bio-oil) in the distillation zone.

Under the conditions of the esterification reaction, the water formed by the reaction is removed in the form of vapors, and only the resulting bio-oil flows down the trays of the column to the bottom of the reactor. Thus, almost no water exists on the trays in the bottom part (13b) of the column reactor, which makes it possible to complete the reaction without any reverse reaction occurring. Effective ingredients that may be lost as reaction vapors are returned from the distillation zone to the reaction zone of the reactor, whereby the loss of effective ingredient can be minimized.

A plurality of trays are installed inside the column reactor, each tray (14a) enclosing a plurality of steam channels (14b). According to the tray types, different shapes can be used for the steam channels such as bubbling caps, sieves, valves, etc.

In the present disclosure, the bio-oil resulting from the esterification reaction between glycerol (10) and fatty acid (10') is removed from the bottom of the reactor (15a) along with unreacted starting materials, glycerol (10) and fatty acid (10'). Specifically, the product - bio-oil (glyceride, 18) and unreacted substances, glycerol and fatty acid, are cooled in a refrigerator (16) before extraction. In addition, each plate acts as an obstacle to the rapid passage of unreacted glycerol (10) and fatty acid (10') and allows the feedstock to pass in order, thereby ensuring that sufficient retention times are achieved and conversions are increased. These advantages can lead to the establishment of optimal conditions for obtaining bio-oil with a low acid number.

The flow rate in the reaction zone is set to achieve a retention time of 2 to 6 hours required for the reaction to proceed.

The use of such a column-type reactor makes it possible to produce a bio-oil (glyceride) having the desired low acid number, even in the case of a one-step esterification between fatty acid and glycerol.

In addition, it is possible to minimize the amount of raw material source, including fatty acid and glycerol, as well as finished bio-oil (glyceride), which leave the reactor in the form of vapors along with water and are thus lost. Only water can be effectively removed. Because the reactor is designed to effectively remove only water, it can use the source of raw materials without limitation, regardless of its water content. The bio oil (glyceride) obtained in this way can be used as a heavy bio oil and as an alternative to C bunker oil such as marine fuel oil, industrial oil, etc.

In an exemplary embodiment of the present disclosure, the continuous column reactor of the present disclosure has been found to reduce the proportion of glyceride and fatty acid loss and produce a bio-oil with reduced acid numbers, even if the reaction is carried out at lower temperatures, compared to traditional CSTR reactors (example 15).

Further herein, a better understanding of the present disclosure may be achieved by the following examples and comparative examples, which are set forth for the purpose of explanation, but should not be construed to limit the present disclosure.

Analysis Methods

(1) Acid numbers (mg KOH/g) were determined by the indicator titration method according to KSM ISO 6618.

(2) Moisture analysis was performed using the Karl Fischer method.

(3) The concentration of glycerol in the water formed during the reaction was determined by the method in accordance with the KSM standard 2708-6.7.

(4) The content of glycerol and oil were analyzed quantitatively using internal standard calibration curves in accordance with KSM 2412 when they were modified. Internal standards will include butanetriol for glycerol and tricaprin for mono-, di-, and triglyceride. Using internal standards, the content of glycerol, monoglyceride (olein, palmitin), diglyceride and triglyceride (oil content = sum of mono-, di-, triglyceride) was determined.

(5) Fatty acid was analyzed by GC gas chromatography (Internal standard: C17 acid).

Reagents

Raw material source containing fatty acid

(1) Palm oil sludge or palm oil waste liquid (POME), also known as acid palm oil (PAO), which is palm oil extracted by separating the water layer formed by pressing oil from palm fruit.

(2) Palm fatty acid distillate (PFA), which is a by-product from the palm oil production process.

Purified glycerin: x. h. glycerin with a purity of 99% or higher.

Crude Glycerin: Low purity glycerin from oleochemical processes (biodiesel processes, fatty acids).

[Test Examples 1-4] Production of bio-oil according to reaction temperature (batch mode).

Fatty acid (PAO) and glycerol (purified or crude glycerol) were used as raw materials in an experiment to establish operating conditions for a batch type reaction. Together with the fatty acid acid numbers (PAO), Table 1 below shows the content of oil (glyceride), moisture and fatty acid. Used various glycerols with a purity in the range from 9 to 99% of the mass. Purified glycerol was used in Test Example 1 and crude glycerol in Test Examples 2-4. The concentrations of glycerol used in the reaction are shown in Table 1 below.

Together with 200 g of raw material (RAO) containing fatty acid, glycerol was fed into the reactor in an amount corresponding to the molar ratio of fatty acid : glycerol, equal to 3:2. The reactor temperature was raised to 170-250°C. The reaction time was counted from the moment the reaction temperature was reached. The by-product, water (in the vapor state) was cooled at the top of the reactor and continuously removed. The acid numbers of the bio-oil (glyceride) ultimately obtained at the given reaction temperatures are shown in Table 1 below.

Table 1

Temp.
[°C] Content of glycerin in the original raw glycerin Reaction time final
acid number
[mg KOH/g] RAO - - - 154.7 Test
example 1 250 99% or more 2 h 1.71 Test
example 2 250 35% 2 h 5.26 Test
example 3 200 9% 2 h 30.0 Test
example 4 170 35% 2 h 73.4

As shown in Table 1, in Test Examples 1-4, the acid number decreased as the fatty acid was converted to glycerides at temperatures of 170 to 250°C. Specifically, in Test Examples 1 to 3, a reaction temperature of 200 to 250° C. increased the reactivity, resulting in acid numbers of 30 mg KOH/g or less at the end of the reaction. In contrast, the final acid value of Test Example 4 did not satisfy the requirement of the present disclosure.

[Test Examples 5-9] Production of bio-oil according to reaction time (batch mode).

Fatty acid (PAO) and crude glycerol with a purity of 8.8 wt % were used as raw material sources. Fatty acid acid numbers (PAO) and oil (glyceride), moisture and fatty acid content are shown in Table 2 below.

Together with 200 g of fatty acid raw materials (RAO) crude glycerol (9% wt.) was fed into the reactor in an amount corresponding to the molar ratio of fatty acid : glycerol, equal to 3:2. The reactor temperature was raised to 200°C. Upon reaching the reaction temperature, samples were taken and analyzed over time. The by-product, water (in the vapor state) was cooled at the top of the reactor and continuously removed. The acid numbers of the bio-oil (glyceride) ultimately obtained at a given reaction time are shown in Table 2 below, along with the product contents.

table 2

Reaction time Final acid number
[mg KOH/g] Glycerol
[mass. %] Oil
[mass. %] Water
[mass. %] HML
[mass. %] RAO - 154.7 0 23.02 1.402 75.03 Test
example 5 0 h 141.2 1.4 35.46 - 68.46 Test
example 6 1 hour 86.5 3.34 56.5 0.567 41.95 Test
example 7 1 h 45 min 47.6 4.61 71.48 0.444 23.08 Test
example 8 2h 15 min 30.0 5.15 79.76 0.45 14.53 Test
example 9 2 h 30 min 21.8 5.31 84.13 0.28 10.59

As shown in Table 2, at a reaction temperature of 200° C., in Test Examples 5 to 7, the acid number rapidly decreased after a reaction time of up to 1 hour 45 minutes, but could not reach 30 mg KOH/g. In contrast, in Test Example 8, the acid number reached 30 mg KOH/g after a reaction time of 2 hours and 15 minutes, and decreased further to 21.8 mg KOH/g after 2 hours and 30 minutes in Test Example 9. Thus, it has been found that a reaction time of two hours or more is required.

[Test Examples 10-14] Production of Bio-Oil According to Mixing Ratio (Molar Ratio) of Fatty Acid and Glycerin (Batch Mode)

Fatty acid (PAO) and crude glycerol with a purity of 35 wt % were used as raw material sources. Table 3 below shows fatty acid acid numbers (PAO) and oil (glyceride), moisture and fatty acid content. Together with 200 g of radioactive waste, crude glycerol was fed into the reactor. In this regard, the amount of the reaction raw material component, crude glycerol, was determined in accordance with the molar ratios given in Table 3 below.

The reaction temperature was set to 250°C, but 200°C for Test Example 11. The reaction time was counted after the reactor was heated to the desired reaction temperatures.

Table 3

Molar ratio
IFA: glycerin Pace.
[°C] Reaction time
[h] final
acid number
[mg KOH/g] Glycerol
[mass. %] Oil
[wt%] Moisture
[wt%] HML
[wt%] RAO - 154.7 0 23.02 1.402 75.0 Test
example 10 3:2 250 2.5 2.82 4.03 88.31 0.26 1.4 Test
example 11 3:1.5 200 3.5 10.64 3.16 89.58 0.396 5.2 Test
example 12 3:1 250 5.5 4.50 0.03 97.35 0.17 2.18 Test
example 13 3:0.75 250 4.5 10.49 0.000 96.931 - 5.1 Test
example 14 3:0.5 250 3 46.97 0.000 76.535 - 22.8

As shown in Table 3, in the case of testing the molar ratios (mixing ratios) of fatty acid and glycerol, the acid number decreased to below 50 mg KOH/g under all conditions of Test Examples 10-14, and specifically to 30 mg KOH/g or less in Test Examples 10-13, where the mole ratio (mixing ratio) of fatty acid (FFA) to glycerol was set to 3:0.75-2. In the case of Test Examples 10-12, the final products were found to contain trace amounts of glycerol. More glycerol input is more likely to lower the acid number, but the specified component is found in greater excess in the final product, which requires an additional glycerol separation process.

[Example 15] Comparison of a continuous column reactor and a CSTR reactor for producing bio-oil (raw oil feedstock).

A comparison was made between acid numbers and loss fractions for bio-oils produced with a continuous column reactor and a CSTR reactor (Table 4 below). The percentage loss of glyceride and fatty acid, presented in table 4, was calculated according to equation 2, reflecting the ratio of the amount of glyceride and fatty acid removed in the form of vapors to the amount of biooil removed from the bottom of the reactor.

[Equation 2]

(1) Example. Application of a continuous column reactor

The operating conditions of Test Examples 1-14 were used for batch reaction. Bio-oil was obtained at a reaction temperature of 250°C and atmospheric pressure. No catalysts were used. The raw material source included fatty acid feedstock PAO (acid value 139 mg KOH/g) and crude glycerol (glycerol content 48 wt. %). RAO was fed into the reactor with heating, while crude glycerol was fed into the reactor without heating.

The following conditions were set: feed flow rate: PAO 13.6 g/min, crude glycerol 1.8 g/min [molar ratio of IFA: glycerol = 3: approx. 0.8], product flow rate 14.0 g/min and retention time in the reactor 4.5 hours. Vapors were removed from the top of the reactor. The physical properties of the final bio-oil (glyceride) are shown in Table 4 below.

(2) Comparative example. Using the CSTR Reactor

Bio-oil was obtained at a reaction temperature of 250°C and atmospheric pressure. No catalysts were used. The raw material source included fatty acid raw material PAO (acid value 139 mg KOH/g), crude glycerin (SG, glycerol content 48% wt.) at a molar ratio of 3: approx. 0.8. A mixed source of raw materials (RAW and SG) was fed into the reactor when heated.

The following conditions were set: feed flow rate (RAW and SG in the mixture) 9.5 g/min, product flow rate 8.6 g/min, and retention time in the reactor 2 hours. Vapors were removed from the top of the reactor. The physical properties of the final bio-oil (glyceride) are shown in Table 4 below.

(3) Results

Table 4

Example
(column type reactor) C. Example
(CSTR reactor) Acid number
[mg KOH/g] 22 (Retention time 4.5 h) 46.5
(Retention time 2 h) 34.6 (Retention time 2.25 h) - Percentage Loss of Glyceride and Fatty Acid (wt %) 0.2~0.25 2.82

Fig. 5 is a plot of acid numbers versus reactor core temperatures and reactor retention time for this example. The reaction zone inside the column-type reactor used in this example was maintained at a temperature of 140 to 243°C from the top to the middle of the reactor and 245°C from the middle to the bottom of the reactor. As shown in FIG. 5, it was determined that a sample of bio-oil (glyceride) taken from the middle region of the reaction zone in a column reactor at a retention time of 2.25 hours (example) had an acid value of 34.6 mg KOH/g, which is close to the target acid value 30 mg KOH/g despite the lower section temperature compared to the reaction temperature of 250°C. The acid number was below 46.5 mg KOH/g, which was the acid number measured at a retention time of 2 hours in a CSTR reactor (comparative example) (the reaction temperature was maintained at 250° C. during the retention time). In addition, the acid number reached 30 mg KOH/g or less at a retention time of 4.5 hours in a column reactor (example). The results of the reaction in the column reactor (Example) under lower temperature conditions were similar or better than those of the CSTR reactor (Comparative Example) obtained under higher temperature conditions, indicating that the column reactor (Example) is better reaction efficiency.

[Example 16] Production of Bio-Oil Using a Continuous Column Reactor (FPFA Feedstock)

Heavy biooil was obtained at 250°C at atmospheric pressure, without a catalyst, by sequentially feeding FPFA and crude glycerol into a column reactor. Raw materials, DPFA (acid value 189 mg KOH/g; ultra-high acid number oil) and crude glycerol (glycerol content 36%), were used at a fatty acid (FAA) : glycerol molar ratio of 3:0.9 at rates feed 12.8 g/min for DPFA and 3.3 g/min for crude glycerin. FPFA was fed into the reactor with heating, while crude glycerol was fed into the reactor without heating.

The water formed as a reaction product and the water contained in the crude glycerol were removed as vapors in the upper part of the reactor, while the bio-oil (glyceride), as well as unreacted glycerol and fatty acid, were removed at a rate of 13.3 g/min from bottom of the reactor. The retention time was about 5 hours.

The bio-oil obtained at a retention time of 5 hours had an acid value of 26.2 mg KOH/g, which demonstrates that a bio-oil with an acid value of 30 mg KOH/g or less can be produced in the continuous column reactor of the present disclosure even when using sources of raw materials with ultra-high acid numbers (high content of fatty acids).

While the technical scope of the present disclosure has been described by way of the examples set forth in some embodiments and illustrated with the accompanying drawings, it should be noted that various substitutions, modifications, and changes can be made without departing from the scope of the present disclosure, which may be understood by those skilled in the art. technique to which the present disclosure relates. In addition, it should be noted that such substitutions, modifications and alterations are intended to fall within the scope of the appended claims.

Claims (17)

1. A method for producing biooil, including the following stages, in which: carry out the esterification of the source of raw materials containing glycerol and fatty acid, to obtain bio-oil and water in a column-type reactor, which has a plurality of trays installed in it, forming a plurality of compartments in the vertical direction inside the reactor, while each of the plurality of trays has a hole formed in it, through which vertically adjacent compartments communicate with each other, with holes in adjacent trays formed in a cross pattern, while the source of raw material containing glycerol and fatty acid is fed through the corresponding material inlet channels located in the center of the column reactor, for carrying out esterification on each plate of the reaction zone; remove the resulting bio-oil through the bottom of the reactor; And remove the esterification water by evaporation, transfer the generated water vapor to the distillation zone located at the top of the reactor, together with the effective ingredients, including the raw material source and the bio-oil, which turn into steam upon evaporation, separate the steam into water and effective ingredients , including a source of raw materials and bio-oil, and allow effective ingredients to pass into the reaction zone, and the separated water is removed in a vapor state through the top of the reactor, wherein the bio-oil has an acid value of 30 mg KOH/g or lower, and the esterification reaction is carried out at a temperature of 170 to 350° C. at atmospheric pressure without using a catalyst. 2. The process of claim 1, wherein water passes through a steam channel formed in each tray, is separated, and removed in a distillation zone at the top of the column reactor. 3. The method of claim 2, wherein the plurality of steam channels formed in each tray is selected from the group consisting of bubbling caps, valves, and orifices. 4. The method of claim 1, wherein the bottom of the column reactor is a reaction zone in which glycerol is esterified with a fatty acid to produce glyceride as a product, and the top of the column reactor is a distillation zone in which water is evaporated as a by-product esterification and remove it in the vapor state. 5. The method of claim 4 wherein the glycerol and fatty acid remain in the reaction zone for a retention time of 2 hours or longer. 6. The method according to claim 1, in which the fatty acid and glycerol are used at a mixing ratio in a molar ratio of from 3:0.5 to 3:2. 7. The method according to claim 1, wherein the raw material comprising the fatty acid has an acid number greater than 30 mg KOH/g. 8. Process according to claim 1, wherein the esterification is carried out at a reaction temperature of 170 to 350°C. 9. The method according to claim 1, wherein the bio-oil as a reaction product has an acid value of 25 mg KOH/g or less. 10. The method according to p. 1, in which the glycerol has a concentration of glycerol from 3 to 100% of the mass. 11. The method of claim. 1, in which water and effective ingredients, including the source of raw materials and biooil, are separated by boiling point. 12. The method of claim 7, wherein the raw material source comprising the fatty acid is selected from the group consisting of a soap-derived fatty acid oil, which is a soapy substance resulting from the removal of the free fatty acid during a vegetable oil refining process; products or by-products resulting from a process involving animal and vegetable fat and oil, or oleochemical products, which are chemical products derived from animal and vegetable fat and oil; oil containing fatty acids resulting from the extraction of oil and the refining of vegetable/animal oils and fats; recoverable oil, including waste edible oil and dark fat; as well as their combinations. 13. The method of claim 1, wherein the reaction is carried out for a reaction time of 2 hours or longer.