Catalyst for producing hydrogenated biodiesel and method of producing the same

Abstract

Disclosed herein is a catalyst for producing biodiesel, including a carrier having water resistance and an active component supported on the carrier and used in a hydrotreating reaction or a decarboxylation reaction. Since the catalyst for producing biodiesel includes a carrier having strong water resistance, the deactivation of the catalyst due to the water produced through a process of producing HBD can be prevented, thus remarkably improving the long term stability of a catalyst.

Claims

1. A method of producing biodiesel through a hydrotreating reaction or a decarboxylation reaction in the presence of a catalyst comprising a carrier having water resistance and an active component supported on the carrier and used in a hydrotreating reaction or a decarboxylation reaction, wherein the carrier is not alumina, and wherein the active component is not leached out when the catalyst has been reacted for 30 days.

2. The method of producing biodiesel according to claim 1, wherein the catalyst comprises a group VIB metal as the active component supported on the carrier.

3. The method of producing biodiesel according to claim 2, wherein the catalyst further comprises a group VIM metal or a group VIII metal as the active component supported on the carrier.

4. The method of for producing biodiesel according to claim 1, wherein the carrier is selected from among zirconia, titania, aluminum phosphate, niobia, zirconium phosphate, titanium phosphate, silicon carbide, carbon and mixtures thereof.

5. The method of for producing biodiesel according to claim 2, wherein the group VIB metal is Mo or W, and the amount thereof is 0.1-70 wt % among total active agent.

6. The method of for producing biodiesel according to claim 3, wherein the group VIII metal is Ni, Pd or Pt, and the amount thereof is more than 0 and less than or equal to 60 wt % among total active agent.

7. The method of producing biodiesel according to claim 3, wherein the group VIIB metal is Co, Ru, Fe, Mn or Ir, and the amount thereof is more than 0 and less than or equal to 60 wt % among total active agent.

8. The method of producing biodiesel according to claim 2, wherein the group VIB metal is present in an amount of 1-40 wt % based on the carrier.

9. The method of producing biodiesel according to claim 3, wherein the group VIII metal or group VIIB metal is present in an amount of more than 0 and less than or equal to 20 wt % based on the carrier.

10. The method of producing biodiesel according to claim 1, wherein biomass, such as plant oil, plant fat, animal fat, fish oil, recycled fat, plant fatty acids, animal fatty acids or mixtures thereof, is used as a feed.

11. The method of producing biodiesel according to claim 10, wherein the plant fat, animal fat or recycled fat includes triglycerides, each chain of which is composed of 1-28 carbon atoms, and each of the plant fatty acids or animal fatty acids has 1-28 carbon atoms.

12. The method of producing biodiesel according to claim 10, wherein, in addition to the biomass, one or more hydrocarbon mixtures are used as the feed.

13. The method of producing biodiesel according to claim 12, wherein the hydrocarbon includes kerosene, diesel, light gas oil, and recycled hydrogenated biodiesel.

14. The method of producing biodiesel according to claim 1, the method comprises the steps of: pretreating a feed through hydrotreatment; separating unreacted hydrogen after a hydrodeoxygenation reaction to form hydrocarbons; and cooling, separating and isomerizing the formed hydrocarbons.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) The above and other objects, features and advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

(2) FIG. 1 is a view showing a process of producing HBD when only plant oil is used as a feed; and

(3) FIG. 2 is a view showing a process of producing HBD when a mixture of plant oil and hydrocarbons is used as a feed.

BEST MODE FOR CARRYING OUT THE INVENTION

(4) Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings.

(5) When the commercial hydrotreating catalyst is used to produce HBD, it is difficult to produce HBD for a long period of time since the hydrotreating catalysts has become deactivate. As previous stated, prior arts have many efforts to overcome the problem but has been limitedly solved through process operation control, such as a process of recycling the reacted HBC fraction but a catalyst specified in the HBD reaction has not been developed yet.

(6) The present inventors found the fundamental cause of lowering long-term catalyst activity that the side reaction in the process of HBD formation reaction produced the water which leached out the active sites of catalyst thus resulted in the deactivation of catalyst.

(7) Therefore, the present inventors minimized the deactivation of the catalyst by introducing active sites into a water-resistant carrier having a hydrogenation function. Further, in the course of the present research, it was found that the hydrotreating catalyst manufactured using the technology of the present invention maintains higher long-term catalyst activity than that of the commercial hydrotreating catalyst by two fold or more in the process of producing HBD.

(8) Plant oil mainly consists of triglycerides. As below figure, in the general hydrotreating process, triglycerides reacted by hydrogen produces normal paraffin such as C14-C18 and byproducts such as propane, H2O, CO, CO2.

(9) ##STR00001##

(10) The paraffin produced at this time is C14-C18, and it is commonly named as HBD since it is diesel oil. The above produced H2O unavoidably results in dissolving the catalyst. When Group III+Group IV metal/carrier catalyst of the commercial hydrotreating catalyst is used, H2O is produced with rate of about 10 wt %. After a while a small amount of water does not influence the leaching out of catalyst carrier very much, increased amount of water causes the carrier to be leached out and thus the catalyst to be deactivated.

(11) The present invention provides a catalyst for producing biodiesel, including a carrier having water resistance and an active component supported on the carrier and used in a hydrotreating reaction or a decarboxylation reaction.

(12) The carrier used in the present invention is selected from among zirconia, titania, aluminum phosphate, niobia, zirconium phosphate, titanium phosphate, silicon carbide, carbon and mixtures thereof.

(13) The present invention provides a catalyst for producing HBD (hydrogenated biodiesel), which is used to produce a diesel fraction from biomass through a hydrotreating reaction or a decarboxylation reaction, and which is a catalyst formed by adding an active material having a hydrogenation function or a decarboxylation function to a carrier having strong water resistance, such as zirconia, titania, aluminum phosphate, niobia, zirconium phosphate, titanium phosphate, silicon carbide, carbon and mixtures thereof or the like. In the catalyst of the present invention, a carrier having strong water resistance is used, so that the deactivation of the catalyst due to the water produced through a process of producing HBD can be prevented, thereby remarkably improving the long term stability of the catalyst.

(14) The catalyst used in the present invention can be applied to a hydrotreating reaction or a decarboxylation reaction using an alumina declining durability of carrier due to generated water as well as to a process of producing HBD.

(15) When the catalyst of the present invention is used in a process of producing HBD, the catalyst used in a hydrotreating reaction or a decarboxylation reaction can be used in the process of producing HBD without limitation, and the catalyst in which a carrier is supported with a group VIB metal as an active component can also be used in the process of producing HBD.

(16) Further, in the catalyst of the present invention, a carrier having strong water resistance can be supported with a group VIB metal or a group VIIB metal as another active component in addition to the group VIB metal.

(17) As the active component used in the present invention, the group VIB metal may be Mo or W, the group VIII metal may be Ni, Pd or Pt, and the group VIIB metal may be Co, Ru, Fe, Mn or Ir, but the present invention is not limited thereto.

(18) The catalyst of the present invention includes 0.170 wt % of a group VIB metal as an active component. When the amount of the group VIB metal included in the catalyst is less than 0.1 wt %, the activity of the catalyst is very low, thus the catalyst cannot serve as a catalyst. When the amount thereof is more than 70 wt %, it is difficult to support the group VIB metal on the catalyst in an oxidation state. Preferably, the amount of the group VIB metal may be 140 wt %.

(19) Further, the catalyst of the present invention includes 060 wt % of a group VIII metal or a group VIIB metal as an active component. When the amount of the group VIII metal or group VIIB metal is more than 60 wt %, it is difficult to support the group VIII metal or group VIIB metal on the catalyst. Preferably, the amount of the group VIII metal or group VIIB metal is 020 wt %.

(20) In the process of producing biodiesel according to the present invention, biomass, such as plant oil, plant fat, animal fat, fish oil, recycled fat, plant fatty acids, animal fatty acids or mixtures thereof, can be used as a feed.

(21) As the plant fat, animal fat or recycled fat, fat including triglycerides, each chain of which is composed of 128 carbon atoms may be used, and, as the plant fatty acids or animal fatty acids, fatty acids having 128 carbon atoms may be used, but the present invention is not limited thereto.

(22) In the process of producing biodiesel, in addition to the biomass, one or more hydrocarbon mixtures (099%) may be used as a feed. This hydrocarbon may include kerosene, diesel, light gas oil (LGO), and recycled HBD, but the present invention is not limited thereto.

(23) The process of producing biodiesel may include the steps of: pretreating a feed through hydrotreatment; separating unreacted hydrogen after a hydrodeoxygenation reaction to form hydrocarbons; and cooling, separating and isomerizing the formed hydrocarbons. If necessary, one or two steps may be added or omitted.

(24) A process of producing HBD using only plant oil as a feed is shown in FIG. 1, but is not limited thereto.

(25) FIG. 2 is a view showing a process of producing HBD when a mixture of plant oil and hydrocarbons is used as a feed. The process of producing HBD using the mixture of plant oil and hydrocarbons is different from the process of producing HBD using the only plant oil in the point that a fractionator for separating hydrocarbons is required.

(26) In the process of producing HBD, a mixture in which 1% of dimethyl disulfide (DMDS) is mixed with plant oil is also used as a feed. This feed is simultaneously introduced into a HBD reactor together with hydrogen, and then hydrotreated to form a reaction product. The reaction product is distilled in a stripper and then fractionated according to boiling point. Thus, among the fractionated reaction product, HBD is selectively extracted, and others are recycled.

Mode for the Invention

(27) Hereinafter, a catalyst for producing HBD and a method of producing biodiesel through a hydrotreating process using the catalyst will be described in detail with reference to the following Examples.

EXAMPLES

Example 1: Preparation of a Mo/ZrO2 Catalyst

(28) A catalyst containing about 10 wt % of molybdenum (Mo) was prepared using a zirconia (ZrO2) carrier having a diameter of 1 mm.

(29) Ammonium heptamolybdate tetrahydrate (hereinafter, referred to as AHM) was used a molybdenum (Mo) precursor. A zirconia (ZrO2) carrier was impregnated with an aqueous solution formed by dissolving AHM in distilled water, dried at a temperature of 150 C. for 2 hours, and then continuously calcined at a temperature of 500 C. for 2 hours to prepare a Mo/ZrO.sub.2 catalyst (here, in addition to AHM, various types of molybdenum (Mo) precursors may be used, and the molybdenum (Mo) precursor is not limited to AHM).

(30) 6 cc of the Mo/ZrO.sub.2 catalyst prepared through the above procedures was charged in a cylindrical reactor, and then heated to a temperature of 400 C. while introducing hydrogen (H2) into the cylindrical reactor at a flow rate of 16 cc/min with R-LGO including 3 wt % of DMDS at the flow rate of 0.08 cc/min and a reaction pressure of 45 bars, and then pretreated for 3 hours at a temperature of 400 C.

(31) Subsequently, as a feed, soybean oil including 1% of dimethyl disulfide (DMDS) was reacted at a reaction rate of 0.1 cc/min (LHSV=1) using the pretreated Mo/ZrO.sub.2 catalyst under the conditions of a reaction temperature of 350 C., a reaction pressure of 30 bars and a hydrogen flow rate of 100 cc/min. Sampling was conducted every 8 hours to obtain reaction products. The patterns of the obtained reaction products were observed through simulated distillation, and whether the Mo/ZrO.sub.2 catalyst was leached was confirmed through ICP analysis. The results thereof are given in Table 1 and Table 2.

Example 2: Preparation of a NiMo/ZrO2 Catalyst

(32) A catalyst containing about 10 wt % of molybdenum (Mo) and about 3 wt % of nickel (Ni) was prepared using a zirconia (ZrO2) carrier having a diameter of 1 mm. Ammonium heptamolybdate tetrahydrate (hereinafter, referred to as AHM) was used a molybdenum (Mo) precursor, and nickel nitrate hexahydrate (hereinafter, referred to as NNH) was used as a nickel (Ni) precursor. Here, various types of molybdenum (Mo) precursors and various types of nickel (Ni) precursors may be used, and the molybdenum (Mo) precursor and nickel (Ni) precursor are not limited to AHM and NNH, respectively.

(33) A NiMo/ZrO2 catalyst was prepared through the following procedures.

(34) First, a zirconia (ZrO2) carrier was impregnated with an aqueous solution formed by dissolving AHM in distilled water, dried at a temperature of 150 C. for 2 hours, and then continuously calcined at a temperature of 500 C. for 2 hours to prepare a Mo/ZrO.sub.2 catalyst.

(35) Subsequently, the Mo/ZrO.sub.2 catalyst was impregnated with an aqueous solution formed by dissolving NNH in distilled water, dried at a temperature of 150 C. for 2 hours, and then continuously calcined at a temperature of 500 C. for 2 hours to prepare a NiMo/ZrO.sub.2 catalyst.

(36) Thereafter, subsequent procedures were conducted as in Example 1, except that the pretreatment of the NiMo/ZrO.sub.2 catalyst was performed at a temperature of 320 C. The results thereof are given in Table 1 and Table 2.

Example 3: Preparation of a CoMo/TiO2 Catalyst

(37) A catalyst containing about 10 wt % of molybdenum (Mo) and about 3 wt % of cobalt (Co) was prepared using a titania (TiO2) carrier having a diameter of 1 mm. Ammonium heptamolybdate tetrahydrate (hereinafter, referred to as AHM) was used a molybdenum (Mo) precursor, and cobalt nitrate hexahydrate (hereinafter, referred to as CNH) was used as a cobalt (Co) precursor. Here, various types of molybdenum (Mo) precursors and various types of cobalt (Co) precursors may be used, and the molybdenum (Mo) precursor and cobalt (Co) precursor are not limited to AHM and CNH, respectively.

(38) A CoMo/TiO.sub.2 catalyst was prepared through the following procedures.

(39) First, a titania (TiO2) carrier was impregnated with an aqueous solution formed by dissolving AHM in distilled water, dried at a temperature of 150 C. for 2 hours, and then continuously calcined at a temperature of 500 C. for 2 hours to prepare a Mo/TiO.sub.2 catalyst.

(40) Subsequently, the Mo/TiO.sub.2 catalyst was impregnated with an aqueous solution formed by dissolving CNH in distilled water, dried at a temperature of 150 C. for 2 hours, and then continuously calcined at a temperature of 500 C. for 2 hours to prepare a CoMo/TiO.sub.2 catalyst.

(41) Thereafter, subsequent procedures were conducted as in Example 2. The results thereof are given in Table 1 and Table 2.

Example 4: Preparation of a NiW/TiO2 Catalyst

(42) A catalyst containing about 10 wt % of tungsten (W) and about 3 wt % of nickel (Ni) was prepared using a titania (TiO2) carrier having a diameter of 1 mm. Ammonium metatungstate hydrate (hereinafter, referred to as AMT) was used a tungsten (W) precursor, and nickel nitrate hexahydrate (hereinafter, referred to as NNH) was used as a nickel (Ni) precursor. Here, various types of tungsten (W) precursors and various types of nickel (Ni) precursors may be used, and the tungsten (W) precursor and nickel (Ni) precursor are not limited to AMT and NNH, respectively.

(43) A NiW/TiO.sub.2 catalyst was prepared through the following procedures.

(44) First, a titania (TiO2) carrier was impregnated with an aqueous solution formed by dissolving AMT in distilled water, dried at a temperature of 150 C. for 2 hours, and then continuously calcined at a temperature of 500 C. for 2 hours to prepare a W/TiO.sub.2 catalyst.

(45) Subsequently, the W/TiO2 catalyst was impregnated with an aqueous solution formed by dissolving NNH in distilled water, dried at a temperature of 150 C. for 2 hours, and then continuously calcined at a temperature of 500 C. for 2 hours to prepare a NiW/TiO.sub.2 catalyst.

(46) Thereafter, subsequent procedures were conducted as in Example 2. The results thereof are given in Table 1 and Table 2.

Example 5: Preparation of a NiMo/C Catalyst

(47) A catalyst containing about 15 wt % of molybdenum (Mo) and about 5 wt % of nickel (Ni) was prepared using a carbon (C) carrier having a diameter of 1 mm. Ammonium heptamolybdate tetrahydrate (hereinafter, referred to as AHM) was used a molybdenum (Mo) precursor, and nickel nitrate hexahydrate (hereinafter, referred to as NNH) was used as a nickel (Ni) precursor. Here, various types of molybdenum (Mo) precursors and various types of nickel (Ni) precursors may be used, and the molybdenum (Mo) precursor and nickel (Ni) precursor are not limited to AHM and NNH, respectively.

(48) A NiMo/C catalyst was prepared as follows.

(49) A carbon (C) carrier was impregnated with an aqueous solution formed by dissolving AHM and NNH in distilled water, and then dried at a temperature of 300 C. for 2 hours to prepare a NiMo/C catalyst.

(50) Thereafter, subsequent procedures were conducted as in Example 2. The results thereof are given in Table 1 and Table 2.

Example 6: Preparation of a NiMo/AlPO4 Catalyst

(51) A catalyst containing about 15 wt % of molybdenum (Mo) and about 5 wt % of nickel (Ni) was prepared using a aluminum phosphate (AlPO4) carrier. Molybdenum (Mo) precursor, and nickel (Ni) precursor can be used like those of Example 2, respectively.

(52) A NiMo/AlPO4 catalyst was prepared through the following procedures.

(53) First, a aluminum phosphate (AlPO4) carrier was impregnated with an aqueous solution formed by dissolving AHM and NNH in distilled water, dried at a temperature of 150 C. for 2 hours, and then pretreated as in Example 2.

(54) The results thereof are given in Table 1 and Table 2.

Example 7: Preparation of a NiMo/Nb2O5 Catalyst

(55) A catalyst containing about 7 wt % of molybdenum (Mo) and about 2 wt % of nickel (Ni) was prepared using a niobium oxide (Nb2O5) carrier. Molybdenum (Mo) precursor, and nickel (Ni) precursor can be used like those of Example 2, respectively.

(56) A NiMo/Nb2O5 catalyst was prepared through the following procedures.

(57) First, a aluminum phosphate (AlPO4) carrier was impregnated with like Example 6 and then pretreated as in Example 2.

(58) The results thereof are given in Table 1 and Table 2.

Comparative Example 1: Preparation of a NiMo/Al2O3 Catalyst

(59) A catalyst containing about 10 wt % of molybdenum (Mo) and about 3 wt % of nickel (Ni) was prepared using an alumina (Al2O3) carrier having a diameter of 1 mm. Ammonium heptamolybdate tetrahydrate (hereinafter, referred to as AHM) was used a molybdenum (Mo) precursor, and nickel nitrate hexahydrate (hereinafter, referred to as NNH) was used as a nickel (Ni) precursor. Here, various types of molybdenum (Mo) precursors and various types of nickel (Ni) precursors may be used, and the molybdenum (Mo) precursor and nickel (Ni) precursor are not limited to AHM and NNH, respectively.

(60) A NiMo/Al2O3 catalyst was prepared through the following procedures.

(61) First, an alumina (Al2O3) carrier was impregnated with an aqueous solution formed by dissolving AHM in distilled water, dried at a temperature of 150 C. for 2 hours, and then continuously calcined at a temperature of 500 C. for 2 hours to prepare a Mo/Al2O3 catalyst.

(62) Subsequently, the Mo/Al2O3 catalyst was impregnated with an aqueous solution formed by dissolving 3.06 g of NNH in distilled water, dried at a temperature of 150 C. for 2 hours, and then continuously calcined at a temperature of 500 C. for 2 hours to prepare a NiMo/Al2O3 catalyst.

(63) Thereafter, subsequent procedures were conducted as in Example 2. The results thereof are given in Table 1 and Table 2.

Comparative Example 2: Preparation of a CoMo/Al2O3 Catalyst

(64) A catalyst containing about 10 wt % of molybdenum (Mo) and about 3 wt % of cobalt (Co) was prepared using an alumina (Al2O3) carrier having a diameter of 1 mm. Ammonium heptamolybdate tetrahydrate (hereinafter, referred to as AHM) was used a molybdenum (Mo) precursor, and cobalt nitrate hexahydrate (hereinafter, referred to as CNH) was used as a cobalt (Co) precursor. Here, various types of molybdenum (Mo) precursors and various types of cobalt (Co) precursors may be used, and the molybdenum (Mo) precursor and cobalt (Co) precursor are not limited to AHM and CNH, respectively.

(65) A CoMo/Al2O3 catalyst was prepared through the following procedures.

(66) First, an alumina (Al2O3) carrier was impregnated with an aqueous solution formed by dissolving AHM in distilled water, dried at a temperature of 150 C. for 2 hours, and then continuously calcined at a temperature of 500 C. for 2 hours to prepare a Mo/Al2O3 catalyst.

(67) Subsequently, the Mo/Al2O3 catalyst was impregnated with an aqueous solution formed by dissolving CNH in distilled water, dried at a temperature of 150 C. for 2 hours, and then continuously calcined at a temperature of 500 C. for 2 hours to prepare a CoMo/Al2O3 catalyst.

(68) Thereafter, subsequent procedures were conducted as in Example 2. The results thereof are given in Table 1 and Table 2.

(69) From Table 1, in the case of the catalysts prepared using an alumina (Al2O3) carrier, it can be seen that yields rapidly decrease with the passage of reaction time although initial activity is good. In contrast, in the case of the catalysts prepared using a zirconia (ZrO2) carrier, a titania (TiO2) carrier, a carbon (C) carrier, aluminum phosphate carrier, or niobia carrier, as given in Table 1, it can be seen that their initial activity and long-term stability are excellent compared to those of the catalysts prepared using an alumina (Al2O3) carrier. In particular, as given in Table 2, the catalysts prepared using a zirconia (ZrO2) carrier, a titania (TiO2) carrier, a carbon (C) carrier, aluminum phosphate carrier, or niobia carrier have excellent water resistance and do not cause a catalyst dissolving phenomenon, but in the catalysts prepared using an alumina (Al2O3) carrier, their catalyst and carrier component are leached out therefrom and they are rapidly dissolved with the passage of reaction time.

(70) TABLE-US-00001 TABLE 1 Catalyst/diesel selectivity (%) 1 day 15 days 30 days Mo/ZrO.sub.2 83 84 80 NiMo/ZrO.sub.2 86 88 89 CoMo/TiO.sub.2 84 85 86 NiW/TiO.sub.2 89 89 87 NiMo/C 82 82 81 NiMo/AlPO.sub.4 81 80 80 NiMo/Nb.sub.2O.sub.5 78 78 77 NiMo/Al.sub.2O.sub.3 82 79 74 CoMo/Al.sub.2O.sub.3 82 78 76

(71) TABLE-US-00002 TABLE 2 Catalyst/ composition 1 day 15 days 30 days (wppm) Ni Co Mo Zr Ti Al Ni Co Mo Zr Ti Al Ni Co Mo Zr Ti Al Mo/ZrO.sub.2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 NiMo/ZrO.sub.2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 CoMo/TiO.sub.2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 NiW/TiO.sub.2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 NiMo/C NiMo/AlPO.sub.4 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 NiMo/Nb.sub.2O.sub.5 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 NiMo/Al.sub.2O.sub.3 0 0 0 0 0 0 0 0 0 0 0 57 0 0 1.3 0 0 1670 CoMo/Al.sub.2O.sub.3 0 0 0 0 0 0 0 0 0 0 0 45 0 0 0.5 0 0 1250

(72) As described above, the catalyst for producing biodiesel according to the present invention is advantageous in that it has high long-term activity and is not leached, thus improving long term stability.

(73) Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.