TWI472609B - Continuous oil alkylation reactor - Google Patents

Description

Continuous fat alkylation reactor

This invention relates to a reactor, and more particularly to a continuous oil and fat alkylation reactor.

Conventional biodiesel is completed by an alkali process or an acid process. Because of the use of an acid or alkali catalyst, it requires acid-base neutralization, water washing, etc. in the post-treatment, and there is a waste liquid treatment problem. In addition, due to the poor compatibility of methanol with vegetable oil, the transesterification reaction takes a long time, so most of them are batch processes. The main disadvantages of the traditional biodiesel process are as follows: 1. The reaction time is long, generally more than 2 hours. 2. The instruction type and the process are complicated, and the equipment covers a large area. 3. Catalyst, acid-base neutralization, water washing, waste liquid treatment, etc. increase operating costs. 4. The moisture of the raw materials is sensitive to the content of free fatty acids, and is generally controlled to be less than 3%. Therefore, if waste cooking oil is used as a raw material, pretreatment is required to avoid saponification.

According to the literature, the esterification or transesterification reaction of methanol in the supercritical state is completely unaffected by the presence of impurities such as water and free fatty acids in the raw material, and has the following advantages: 1. Fast reaction speed , generally within 30 minutes. 2. Continuous process, simplified steps, and small equipment footprint. 3. No need to add acid-base catalyst, no acid-base neutralization, water washing, waste liquid treatment and other issues. 4. Completely unaffected by the water and fatty acid content of the raw materials.

Republic of China Patent Publication No. 466271 "Method for producing alkyl esters of fatty acids from oils and fats", providing a method for producing esterified diesel fuel by transesterification in a supercritical lower alcohol state without using a metal acid or a base catalyst . The patent can use a source of oil and fat containing free fatty acids to react with a lower alcohol, and transesterify the triglyceride contained in the oil and fat in a supercritical alcohol state to produce an alkyl group of a fatty acid. The ester can be reacted without using a metal base catalyst or an acid catalyst, so that the treatment before the esterification of the free fatty acid is not required, and the by-product of the fatty acid soap is not formed, so that the formation can be omitted or simplified. Recycling and refining of materials. This patent discloses that it is preferred to carry out the reaction of the oil and the alcohol on one side continuously through the tubular reaction vessel, but the method of carrying out the tubular reaction vessel is not described.

U.S. Patent Nos. 6,187,939, 6, 211, 390, 6, 570, 030, and 6, 818, 026 discloses a method of transesterification of supercritical alcohols using a batch of autoclave as a reactor; U.S. Patent Nos. 6812359, 7193097 discloses supercritical alcohol transesterification The process was carried out using a continuous reactor, but did not reveal the method of implementation of the continuous reactor.

According to the literature, a continuous reactor is generally used in a tubular reactor. In order to increase the conversion rate of the transesterification reaction and avoid the occurrence of a reverse reaction, an excess of a lower alcohol (1 to 4 carbon alcohols) is generally used. Class) is also the high alcohol to oil ratio. A stirrer is generally used in the batch type reaction tank to increase the contact area of the alcohol with the oil to improve the reaction efficiency, but it cannot be carried out in the tubular reactor. Excessive low-carbon alcohols can increase the efficiency of the reaction, but recycling in the latter stage wastes more energy.

Since the solubility of low-carbon alcohols to oils and fats is not good, it is necessary to increase the reaction temperature to above 300 °C in order to have a conversion rate of 98% or more, but there are disadvantages of energy consumption, high-temperature cracking, and reduction of fatty acid alkyl ester yield. In addition, the tubular reactor is not easy to maintain the temperature uniformity from the center of the tube to the tube wall when the diameter of the tube is enlarged, which greatly reduces the reaction efficiency and the conversion rate. In addition, the use of metal oxide solid phase catalysts according to the literature can reduce the reaction temperature and increase the conversion rate, but the solid phase catalyst is not easy to implement in the tubular reactor: the powdery catalyst is easy to cause blockage of the pipeline and the valve; porous or mesh Sieve-like catalysts tend to cause large pressure drops and blockage of impurities. What's more, tubular reactors are suitable for medium to low viscosity grease feeds and are not suitable for use with higher viscosity or waste cooking oils or scraps containing solid suspended impurities.

Therefore, it is necessary to provide an innovative and progressive continuous oleoalkylation reactor to solve the above problems.

The invention provides a continuous oil and fat alkylation reactor comprising: a column, a rotor and a heater. The column includes: a first reactant inlet disposed at a top of one of the columns for inputting a first reactant; and a second reactant inlet disposed at a bottom of the column for inputting a second reactant; a second reactant outlet is disposed at the top of the column for outputting the second reactant that is not completely reacted; and a product outlet is disposed at the bottom of the column for outputting the first and second reactants The product after the chemical reaction. The rotor is disposed in the column and includes at least one film forming member for forming a film of the first reactant and flowing downward, wherein the second reactant forms a space along the inner wall of the rotor and the column Flowing upward and contacting the first reactant produces a chemical reaction. The heater is used to heat the column.

The invention further provides a continuous oil and fat alkylation reactor comprising: a column, a rotor and a heater. The column includes: a first reactant inlet disposed at a top of the column for inputting the first reactant; a second reactant inlet disposed at the top of the column for inputting the second reactant; A product outlet is disposed at a bottom of the column for outputting the chemically reacted product of the first and second reactants and the second reactant that is not completely reacted. The rotor is disposed in the column and includes at least one film forming member for forming the first and second reactants into a film and flowing downwardly, wherein the second reactant is in contact with the first reactant Produce a chemical reaction. The heater is used to heat the column.

The invention further provides a continuous oil and fat alkylation reactor comprising: a column, a rotor and a heater. The column includes: a first reactant inlet for inputting the first reactant; a second reactant inlet for inputting the second reactant; and a product outlet for outputting the chemical of the first and second reactants The product after the reaction. The rotor is disposed in the column and is driven to rotate by a driving component, wherein the rotor includes at least one roller and a radial arm for fixing the roller to the periphery of the rotor, a roller for forming a film of one or both of the first and second reactants, the second reactant contacting the first reactant to generate a chemical reaction, the roller being provided with a solid catalyst, Used to enhance the conversion rate of the chemical reaction. The heater is used to heat the column.

The continuous oil and fat alkylation reactor of the invention can be applied to a high-viscosity liquid reactant, and the reactants increase the contact surface area after forming a film, thereby greatly improving the reaction efficiency. In addition, the temperature uniformity control of the film is easy and there is no problem with the radial temperature gradient. The continuous fat alkylation reactor of the invention can be applied to the alkylation reaction under normal pressure or low pressure or the supercritical low alcohol alkylation reaction under high temperature and high pressure.

Referring to Figure 1, there is shown a schematic view of a continuous oleoalkylation reactor of a first embodiment of the present invention. The continuous grease alkylation reactor 10 of the first embodiment of the present invention comprises: a column 11, a rotor 12 and a heater 13. The column 11 has a first reactant inlet 111, a second reactant inlet 112 and a product outlet 113 for inputting the first reactant and the second reactant, respectively, and outputting the product.

In this embodiment, the first reactant inlet 111 is disposed at one of the tops of the column 11, the second reactant inlet 112 is disposed at a bottom of the column 11, and the product outlet 113 is disposed at the column 11 At the bottom, the first reactant has a greater density than the second reactant. The first reactant may be a grease, and the second reactant may be methanol vapor or supercritical methanol. The transesterification/esterification reaction of waste edible oil with methanol is taken as an example, wherein the first reactant is waste cooking oil. The second reactant is methanol vapor or supercritical methanol. The density of the waste cooking oil is about 800-900 kg/m ³ , and the density of the methanol vapor or supercritical methanol is about 200-600 kg/m ³ , that is, the density of the first reactant and the second reactant. The difference is at least greater than about 200 kg/m ³ . Therefore, the first reactant (waste cooking oil) enters at the top of the column 11 and flows downward, and the second reactant (methanol vapor or supercritical methanol) enters at the bottom of the column 11 and flows upward to generate a reaction.

The continuous oleoalkylation reactor 10 of the present invention further includes a second reactant inlet line 114 coupled to the second reactant inlet 112 and projecting onto the bottom of the column 11. The continuous fat alkylation reactor 10 of the present invention further includes a second reactant outlet 115 disposed at the top of the column 11 to allow an excess of unreacted second reactant (methanol vapor or supercritical methanol). It flows out from the second reactant outlet 115, and after being cooled under reduced pressure, it can be recycled and reused.

The rotor 12 is disposed in the column 11 and is driven to rotate by a driving member 14 having at least one film forming member 121 for forming a first reactant to form a film 15 for the first reactant and the second reactant. Produce a reaction.

In the present embodiment, the first reactant (waste cooking oil) enters from the first reactant inlet 111 at the top of the column 11, passes through the centrifugal action of the rotor 12 and the smoothing action of the film forming member 121, in the column 11 The wall forms a film 15 and flows downward due to gravity; the second reactant (methanol vapor or supercritical methanol) enters from the second reactant inlet 112 at the bottom of the column 11, and flows upward through the rotor 12 and the column 11. The space formed by the wall is brought into contact with the film 15 formed by the first reactant (waste cooking oil) to produce a transesterification/esterification reaction. Since the smoothing action of the film forming member 121 continually renews the surface of the film 15 so that the unreacted first reactant (waste cooking oil) is continuously contacted with the second reactant (methanol vapor or supercritical methanol) The esterification/esterification reaction, so the reaction rate is quite fast.

Since the first reactant (waste cooking oil) and the second reactant (methanol vapor or supercritical methanol) are in reverse contact and reaction, the inside of the column 11 can be divided into a mixing zone, a reaction zone, and a separation from top to bottom. Three zones: the mixing zone is a premix of the first reactant (waste cooking oil) and the second reactant (methanol vapor or supercritical methanol), preferably at the first reactant inlet 111 into the column 11 A dispersing or atomizing device is arranged at the cavity to atomize the first reactant (waste cooking oil) into micro droplets, so that the second reactant (methanol vapor or supercritical methanol) is thoroughly mixed and has a diffusion effect, and the excess is unreacted. The second reactant (methanol vapor or supercritical methanol) can be discharged from the second reactant outlet 115, and can be recovered and reused after being cooled under reduced pressure.

After the film 15 is formed in the reaction zone due to the first reactant (waste cooking oil), it has the largest contact area with the second reactant (methanol vapor or supercritical methanol) and thus reacts rapidly and produces a product (fatty acid methyl ester and glycerol). The product in the separation zone (fatty acid methyl ester and glycerol) has a high density and is deposited downward and flows out from the product outlet 113 to a standing tank (not shown) to separate the fresh second reactant (methanol vapor or supercritical). Methanol) migrates upward due to low density and reacts with a trace amount of the first reactant (waste cooking oil) that is not completely reacted, thereby increasing the conversion rate to nearly 100%.

Referring to Figure 2, there is shown a schematic view of a first embodiment of a film forming member of the present invention. In the present embodiment, the film forming member 121 is at least one scraper disposed at the periphery of the rotor 12. At least two or more scrapers 121 are fixed to the rotor 12 by inlaying, locking or riveting. It is preferable that the blade 121 protrudes from the rotor 12 by a distance of 1 to 10 mm. The shape of the blade 121 contacting the inner wall of the column 11 is preferably a blade shape or a wedge shape or a round shape. Further, the scraper 121 may have a spiral groove to push the first reactant (waste cooking oil) film 15 downward with a downward thrust during rotation.

Referring to Figures 3 and 4, there is shown a schematic view of a second embodiment of the film forming member of the present invention. In the present embodiment, the film forming member 221 is at least one roller, the roller 221 is fixed to the periphery of the rotor 22 by the radial arm 222, and the roller 221 is rotated about a roller shaft 223. Wherein both ends of the rotor 22 have radial arms 222 extending to secure the roller shaft 223. Further, a solid catalyst such as nickel (Ni), platinum (Pt) or a metal oxide such as calcium oxide (CaO) or zirconium oxide (ZrO2) may be used to enhance the conversion of the transesterification/esterification reaction. The solid catalyst is mechanically processed or sintered into a roller shape for the roller 221, or is coated, deposited, impregnated, implanted or the like on the surface of the roller 221 whose base material is metal or ceramic. When the rotor 22 rotates, the radial movement of the roller 221 along the inner wall of the column through the radial arm 222 produces a knife-like action to form the first reactant (waste cooking oil) into the film 15, while the roller 221 is wound around the roller. The shaft 223 generates a rotation motion, thereby continuously contacting and renewing the solid catalyst on the roller 221 with the first reactant (waste cooking oil) film 15, thereby effectively improving the reaction efficiency.

Referring to FIG. 1 again, the heater 13 is used to heat the column 11 and is disposed around the column 11 to make the temperature uniformity control of the first reactant (waste cooking oil) film 15 on the inner wall of the column 11 easy. Less problem with radial temperature gradients.

Referring to Figure 5, there is shown a schematic view of a continuous oleoalkylation reactor of a second embodiment of the present invention. The continuous grease alkylation reactor 30 of the second embodiment of the present invention comprises: a column 31, a rotor 32 and a heater 33. The second embodiment of the present invention relates to a continuous oleoalkylation reactor 30 which differs from the continuous oleoalkylation reactor 10 of the first embodiment in that the first reactant inlet 311 and the second reactant inlet 312 are both Located at the top of one of the columns 31, the product outlet 313 is disposed at the bottom of one of the columns 31.

In this embodiment, the first reactant may be oil and fat, and the second reactant may be liquid methanol, taking the transesterification/esterification reaction of waste edible oil and methanol as an example, wherein the first reactant is waste cooking oil. The second reactant is liquid methanol. Since the density of the waste cooking oil is about 800-900 kg/m ³ , the difference between the density of the liquid methanol and the density of the liquid methanol is about 700-800 kg/m ³ , that is, the difference between the density of the first reactant and the second reactant is at least less than about 200kg/m ³ , so the top stream is fed on the top of the column 31, the first reactant (waste cooking oil) enters from the first reactant inlet 311 at the top of the column, and the second reactant (liquid methanol) is self-contained. The second reactant inlet 312 at the top of the column 31 enters.

After the first reactant (waste cooking oil) is premixed with the second reactant (liquid methanol), the mixture of the first reactant (waste cooking oil) and the second reactant (liquid methanol) is centrifuged by the rotor 32 and The smoothing action of the film forming member 321 forms a film 35 on the inner wall of the column 31, and flows downward due to gravity and the spiral action of the film forming member 321.

The film 35 of the first reactant (waste cooking oil) and the second reactant (liquid methanol) undergoes a transesterification/esterification reaction, and the second reactant is continuously continually applied due to the smoothing and agitation of the film forming member 321 ( The liquid methanol) is sufficiently mixed with the first reactant (waste cooking oil) to promote the progress of the reaction, so that the reaction rate is faster than the conventional use of the stirring blade.

Since the first reactant (waste cooking oil) and the second reactant (liquid methanol) are mixed and reacted in the same direction, the inside of the column can be divided into three regions of a mixing zone, a reaction zone and a separation zone from top to bottom. The mixing zone is a premix of the first reactant (waste cooking oil) and the second reactant (liquid methanol), preferably at the first reactant inlet 311 and the second reactant inlet 312 into the interior of the column 31 Disposing a dispersing or atomizing device to atomize the first reactant (waste cooking oil) and the second reactant (liquid methanol) into micro droplets, so that the first reactant (waste cooking oil) and the second reactant (liquid methanol) ) Premixed and diffused.

In the reaction zone, since the first reactant (waste cooking oil) and the second reactant (liquid methanol) form the film 35, the mixture is uniform and the heat is supplied to the heater 33 to promote the reaction, so the reaction is rapid and the product is produced (fatty acid methyl ester). With glycerin). The unreacted second reactant (liquid methanol) and the product (fatty acid methyl ester, glycerol) are deposited downward in the separation zone and flow out from the product outlet 313 to a standing tank (not shown) to be layered and allowed to stand. The methanol in the tank can be separated from the product (fatty acid methyl ester, glycerol) by heating to methanol vapor, and recovered by condensation.

The continuous oil and fat alkylation reactor of the invention can be applied to a high-viscosity liquid reactant, and the reactants increase the contact surface area after forming a film, thereby greatly improving the reaction efficiency. In addition, the temperature uniformity control of the film is easy and there is no problem with the radial temperature gradient. The continuous fat alkylation reactor of the invention can be applied to the alkylation reaction under normal pressure or low pressure or the supercritical low alcohol alkylation reaction under high temperature and high pressure.

However, the above embodiments are merely illustrative of the principles of the invention and its effects, and are not intended to limit the invention. Therefore, those skilled in the art can make modifications and changes to the above embodiments without departing from the spirit of the invention. The scope of the invention should be as set forth in the appended claims.

10. . . Continuous fat oil alkylation reactor of the first embodiment of the present invention

11. . . Column

12. . . Rotor

13. . . Heater

14. . . Drive component

15. . . film

30. . . Continuous fat oil alkylation reactor of the second embodiment of the present invention

31. . . Column

32. . . Rotor

33. . . Heater

35. . . film

111. . . First reactant inlet

112. . . Second reactant inlet

113. . . Product export

114. . . Second reactant inlet line

115. . . Second reactant outlet

121. . . Film forming element

221. . . Film forming element

222. . . Radial arm

223. . . Roller shaft

311. . . First reactant inlet

312. . . Second reactant inlet

313. . . Product export

321. . . Film forming element

Figure 1 is a schematic view showing a continuous fat alkylation reactor of a first embodiment of the present invention;

Figure 2 is a schematic view showing a first embodiment of the film forming member of the present invention;

Figure 3 is a side elevational view showing a second embodiment of the film forming member of the present invention;

Figure 4 is a cross-sectional view showing a second embodiment of the film forming member of the present invention;

Figure 5 is a schematic view showing a continuous fat alkylation reactor of a second embodiment of the present invention.

10. . . Continuous fat oil alkylation reactor of the first embodiment of the present invention

11. . . Column

12. . . Rotor

13. . . Heater

14. . . Drive component

15. . . film

111. . . First reactant inlet

112. . . Second reactant inlet

113. . . Product export

114. . . Second reactant inlet line

115. . . Second reactant outlet

121. . . Film forming element

Claims (9)

A continuous fat alkylation reactor comprising: a column comprising: a first reactant inlet disposed on top of one of the columns for inputting a first reactant; a second reactant inlet disposed in the tube One of the bottoms of the column is for inputting the second reactant; a second reactant outlet is disposed at the top of the column for outputting the second reactant which is not completely reacted; and a product outlet is disposed at the column a bottom portion for outputting the chemically reacted product of the first and second reactants; a rotor disposed in the column and including at least one film forming member for forming the first reactant into a film and down Flowing, wherein the second reactant flows upward along a space formed by the rotor and the inner wall of the column and contacts the first reactant to generate a chemical reaction; and a heater for heating the column. A continuous fat alkylation reactor according to claim 1 wherein the density of the first reactant is greater than the density of the second reactant and the difference in density is greater than about 200 kg/m ³ . The continuous fat alkylation reactor of claim 2, wherein the first reactant is a grease and the second reactant is methanol vapor or supercritical methanol. The continuous fat alkylation reactor of claim 1, wherein the film forming member is at least one scraper disposed at a periphery of the rotor. A continuous fat alkylation reactor according to claim 4, wherein the scraping tool There are spiral grooves. A continuous grease alkylation reactor according to claim 1, wherein the film forming member is at least one roller, and the rotor further comprises a radial arm for fixing the roller to the periphery of the rotor. A continuous oleoalkylation reactor according to claim 6 wherein the roller is a solid catalyst. A continuous oleoalkylation reactor according to claim 6 wherein the surface of the roller has a solid catalyst. A continuous fat alkylation reactor comprising: a column comprising: a first reactant inlet for inputting a first reactant; a second reactant inlet for inputting a second reactant; and a product outlet a chemically reacted product for outputting the first and second reactants; a rotor disposed in the column and driven to rotate by a driving element, wherein the rotor includes at least one roller and a radial arm The radial arm is configured to fix the roller to a periphery of the rotor, the roller is configured to form a film of one or both of the first and second reactants, the second reactant and the The first reactant contacts to produce a chemical reaction, the roller is provided with a solid catalyst to enhance the conversion rate of the chemical reaction, and a heater is used to heat the column.