Method of making an asphalt composition containing ester bottoms

Abstract

This invention involves the addition of ester bottoms to an asphalt paving composition to improve the usable temperature range (UTR). The ester bottoms are a byproduct of refining a feedstock containing all or a portion of vegetable oil or animal fat.

Claims

1. A method of making .[.paving.]. .Iadd.a modified .Iaddend.asphalt .Iadd.composition .Iaddend.comprising: adding 0.1 wt % to .[.20.]. .Iadd.50 .Iaddend.wt % ester bottoms to an asphalt mixture wherein the ester bottoms are a byproduct of methyl ester refining; and adding 0-20 wt % of a polymer modifier to the ester bottoms and asphalt mixture.

2. The method .[.according to.]. .Iadd.of .Iaddend.claim 1.Iadd., .Iaddend.wherein the ester bottoms contain .Iadd.one or more of .Iaddend.methyl esters, .[.sodium soap,.]. monoglycerides, diglycerides, triglycerides, .[.and.]. .Iadd.or .Iaddend.unsaponifiables.

3. The method .[.according to.]. .Iadd.of .Iaddend.claim 2.Iadd., .Iaddend.wherein the unsaponifiables make up about 10 wt % of the ester bottoms.

4. The method of claim 1.Iadd., .Iaddend.wherein the ester bottoms have a viscosity range of 10-900 .[.cp.]. .Iadd.cP .Iaddend.at 64° C.

5. A method of making a .[.paving.]. .Iadd.modified .Iaddend.asphalt .Iadd.composition .Iaddend.comprising adding ester bottoms to an asphalt mixture to increase the useable temperature range of the paving asphalt, wherein the ester bottoms are a byproduct of methyl ester refining.

6. A method of making a .[.paving.]. .Iadd.modified .Iaddend.asphalt .Iadd.composition .Iaddend.comprising adding ester bottoms to an asphalt mixture to meet a predetermined useable temperature range, wherein the ester bottoms are a byproduct of methyl ester refining.

.Iadd.7. A method of making a modified asphalt composition, the method comprising: reacting methanol and dry oil to generate reaction products, the reaction products including at least methyl ester and glycerin, the dry oil being an oil that is at least partially dried to remove moisture therefrom; settling the glycerin from the reaction products; creating a distillation feedstock that has at least a portion of the glycerin removed from the reaction products; distilling the distillation feedstock; recovering distillation bottoms as ester bottoms; and adding the ester bottoms and an asphalt-modifying polymer to an asphalt to define a modified asphalt composition, the ester bottoms being between about 0.1 wt % to about 50 wt % of the modified asphalt composition, the asphalt-modifying polymer being between about 0 wt % to about 20 wt % of the modified asphalt composition, and the asphalt being between about 50 wt % to about 99.9 wt % of the modified asphalt composition..Iaddend.

.Iadd.8. The method of claim 7, wherein the reacting of the methanol and the dry oil includes reacting the methanol and the dry oil in a multistage continuous reactor and adding methoxide catalyst to one or more stages of the multistage continuous reactor..Iaddend.

.Iadd.9. The method of claim 7, wherein the ester bottoms are added to the asphalt in an amount to achieve a preselected useable temperature range of the modified asphalt composition..Iaddend.

.Iadd.10. The method of claim 7, wherein the ester bottoms include unsaponifiables in an amount of at least about 10% thereof..Iaddend.

.Iadd.11. The method of claim 7, wherein the ester bottoms have a viscosity range of between about 10 cP and about 900 cP at 64° C..Iaddend.

.Iadd.12. The method of claim 7, wherein the ester bottoms include diglycerides and triglycerides..Iaddend.

.Iadd.13. The method of claim 7, wherein the asphalt includes from about 20 wt % to about 60 wt % recycled asphalt..Iaddend.

.Iadd.14. The method of claim 7, wherein the asphalt-modifying polymer has one or more monomers selected from the group consisting of butadiene, styrene, vinyl acetate, ethylene, propylene, acrylate, isoprene, and acrylamide..Iaddend.

.Iadd.15. The method of claim 7, wherein adding the ester bottoms to the modified asphalt composition increases useable temperature range of the modified asphalt composition..Iaddend.

.Iadd.16. The method of claim 7, wherein the dry oil is derived from one or more of a vegetable oil or an animal fat..Iaddend.

.Iadd.17. A method of making a modified asphalt composition, the method comprising: reacting methanol with dry oil containing one or more of a vegetable oil or an animal fat to generate reaction products, the reaction products including at least methyl ester and glycerin; settling the glycerin from the reaction products; removing at least a portion of the glycerin from the reaction products to leave an ester phase; distilling the ester phase to separate purified methyl esters from ester bottoms; and blending the ester bottoms and an asphalt-modifier with an asphalt to define a modified asphalt composition, the ester bottoms being between about 0.1 wt % to about 50 wt % of the modified asphalt composition, the asphalt-modifier being between about 0 wt % to about 20 wt % of the modified asphalt composition, and the asphalt being between about 50 wt % to about 99.9 wt % of the modified asphalt composition..Iaddend.

.Iadd.18. The method of claim 17, wherein the reading of the methanol and the dry oil includes reacting the methanol and the dry oil in a multistage continuous reactor and adding methoxide catalyst to one or more stages of the multistage continuous reactor..Iaddend.

.Iadd.19. The method of claim 17, wherein the ester bottoms include unsaponifiables in an amount of at least about 10% thereof..Iaddend.

.Iadd.20. The method of claim 17, wherein the ester bottoms have a viscosity range of between about 10 cP and about 900 cP at 64° C..Iaddend.

.Iadd.21. The method of claim 17, wherein the asphalt includes from about 20 wt % to about 60 wt % recycled asphalt..Iaddend.

.Iadd.22. A method of making a modified asphalt composition, the method comprising: reacting methanol with dry oil containing one or more of a vegetable oil or an animal fat to generate reaction products, the reaction products including at least methyl ester and glycerin; settling the glycerin from the reaction products; removing at least a portion of the glycerin from the reaction products to leave an ester phase; washing the ester phase with water to remove one or more of soap, methanol, catalyst or additional glycerin; drying the washed ester phase to define dried methyl esters; distilling the dried methyl esters to separate purified methyl esters from ester bottoms; and blending the ester bottoms and an asphalt-modifier with an asphalt to define a modified asphalt composition, the asphalt-modifier being selected from the group consisting of a polymer, a resin, polyphosphoric acid, gilsonite, lignin, and crumb rubber..Iaddend.

.Iadd.23. The method of claim 22, wherein the modified asphalt composition includes between about 0.1 wt % to about 50 wt % of ester bottoms, between about 0 wt % to about 20 wt % of the asphalt-modifier, and between about 50 wt % to about 99.9 wt % of the asphalt..Iaddend.

.Iadd.24. The method of claim 22, wherein the ester bottoms include unsaponifiables in an amount of at least about 10% thereof..Iaddend.

.Iadd.25. The method of claim 22, wherein the ester bottoms have a viscosity range of between about 10 cP and about 900 cP at 64° C..Iaddend.

.Iadd.26. The method of claim 22, wherein the asphalt includes from about 20 wt % to about 60 wt % recycled asphalt..Iaddend.

.Iadd.27. A method of making a modified asphalt composition that rejuvenates recycled asphalt, the method comprising: reacting methanol and dry oil to generate reaction products, the reaction products including at least methyl ester and glycerin, the dry oil including one or more of a vegetable oil or an animal fat that has at least some moisture removed therefrom prior to reaction with the methanol; settling the glycerin from the reaction products; removing at least a portion of the glycerin from the reaction products to leave an ester phase; distilling the ester phase to separate purified methyl esters from ester bottoms; and adding the ester bottoms to recycled asphalt to define a modified asphalt composition, the recycled asphalt being obtained from a milled road surface, the ester bottoms being between about 0.1 wt % to about 50 wt % of the modified asphalt composition and the recycled asphalt being between about 50 wt % to about 99.9 wt % of the modified asphalt composition..Iaddend.

.Iadd.28. The method of claim 27, further comprising adding an asphalt-modifying polymer to the modified asphalt composition, the asphalt-modifying polymer being between about 0 wt % to about 20 wt % of the modified asphalt composition..Iaddend.

.Iadd.29. The method of claim 28, wherein the asphalt-modifying polymer is one or more of styrene butadiene, ethylene-vinyl-acetate, ethylene-methyl-acrylate, ethylene butyl acrylate, poly-propylene, atactic polypropylene, polystyrene, polyethylene, LDPE, HDPE, oxidized high density poly-propylene, poly-phosphoric acid, natural rubber, polybutadiene, epoxy resins, polyurethane resins, acrylic resins, phenolic resins, gilsonite, lignin, diblock polymers, styrene-butadiene-styrene, linear triblock polymers, radial triblock polymers. styrene-isoprene-styrene, diblocked polymers, hydrotreated styrene-butadiene-styrene, styrene ethylene butadiene styrene polymers, styrene butadiene rubber, polyacrylamide, glycidyl-containing ethylene copolymers, or crumb rubber..Iaddend.

.Iadd.30. A method of making a modified asphalt composition that resists moisture susceptibility, the method comprising: reacting methanol with dry oil to generate reaction products, the reaction products including at least methyl ester and glycerin, the dry oil including one or more of a vegetable oil or an animal fat that has at least some moisture removed therefrom prior to reaction with the methanol; settling the glycerin from the reaction products; removing at least a portion of the glycerin from the reaction products to leave an ester phase; washing the ester phase with water to remove one or more of soap, methanol, catalyst or additional glycerin; drying the washed ester phase to define dried methyl esters; distilling the dried methyl esters to separate purified methyl esters from ester bottoms; and blending the ester bottoms and an asphalt to define a modified asphalt composition that resists cracking, the ester bottoms being between about 0.1 wt % to about 50 wt % of the modified asphalt composition and the asphalt being between about 50 wt % to about 99.9 wt % of the modified asphalt composition..Iaddend.

.Iadd.31. The method of claim 30, further comprising adding an asphalt-modifying polymer to the modified asphalt composition, the asphalt-modifying polymer being between about 0 wt % to about 20 wt % of the modified asphalt composition..Iaddend.

.Iadd.32. The method of claim 31, wherein the asphalt-modifying polymer is selected from the group consisting of a polymer, a resin, polyphosphoric acid, gilsonite, lignin, and crumb rubber..Iaddend.

.Iadd.33. A method of making a modified asphalt composition, the method comprising: obtaining a distillation bottoms of a distilled methyl ester product that results from reaction between methanol and at least one of vegetable oil or animal fat from which glycerin is settled and removed from the methyl ester product prior to distillation, the distillation bottoms being defined as ester bottoms; obtaining an asphalt, and blending the ester bottoms and the asphalt to define a modified asphalt composition, the ester bottoms being between about 0.1 wt % to about 50 wt % of the modified asphalt composition and the asphalt being between about 50 wt % to about 99.9 wt % of the modified asphalt composition..Iaddend.

.Iadd.34. The method of claim 33, further comprising blending an asphalt-modifying polymer together with the ester bottoms and the asphalt to define the modified asphalt composition, the asphalt-modifying polymer being between about 0 wt % to about 20 wt % of the modified asphalt composition..Iaddend.

.Iadd.35. The method of claim 34, wherein the asphalt-modifying polymer is selected from the group consisting of a polymer, a resin, polyphosphoric acid, gilsonite, lignin, and crumb rubber..Iaddend.

.Iadd.36. The method of claim 33, wherein the asphalt includes recycled asphalt that is obtained from a milled road surface..Iaddend.

Description

IN THE DRAWINGS

(1) FIG. 1 is a schematic flow diagram for bio-refining.

(2) FIG. 2 is a plot of ester bottoms vs. HVGO in asphalt.

(3) FIG. 3 is a plot of ester bottoms PG temperatures for a number of different asphalt compositions.

(4) FIG. 4 is a table of test results on a number of different asphalt compositions when mixed with various amounts of ester bottoms.

(5) FIG. 5 is a table of test results on a number of different asphalt compositions when mixed with various amounts of ester bottoms.

(6) FIG. 6 is a plot of results of tensile tests comparing an ester bottom modified asphalt with three polymer modified asphalts.

(7) FIG. 7 is a plot of results of a rutting resistance test of an ester bottom modified asphalt with three polymer modified asphalts.

(8) FIG. 8 is a plot of results of a compaction tension test comparing an ester bottom modified asphalt with two polymer modified asphalts.

(9) FIG. 9 is a plot of a Semi Circular Bend test comparing an ester bottom modified asphalt with two polymer modified asphalts.

DETAILED DESCRIPTION OF THE INVENTION

(10) Referring to FIG. 1 feedstock is brought from the storage tanks to the dryer (T2101) wherein moisture is removed. This dry oil is then fed into a three-stage continuous reactor/settler system (T2102) where methoxide catalyst and methanol are added to each stage. Methanol reacts with the dry oil to produce methyl ester and glycerin. The dry oil is reacted to less than 1% monoglyceride and virtually no diglycerides or triglycerides as it leaves the last settler. Glycerin settles out of the of the reaction mixture and is directed from the reactors downstream for further refining. The ester phase is what remains after the glycerin is removed. The ester phase is then transferred to a single stage flash distillation tank (V-2107) to remove any remaining methanol. The ester phase is then water washed (T2103) to remove glycerin, soap, methanol, and methoxide catalyst. The washed methyl esters are dried under vacuum (T2104) to remove more methanol and water. Sodium methoxide is added to the dryer to back react any glycerin and monoglycerides into diglycerides and triglycerides. The methyl esters leave the ester dryer and are preheated before entering an ester surge tank (S2201). The methyl esters from the ester surge tank are then distilled to separate the purified methyl esters from the ester bottoms. The ester bottoms are transferred from the distillation tower (T2211) to an ester bottom surge tank (S2202) while the purified methyl ester is transferred from the distillation tower to a storage tank for distribution or sale.

(11) The ester bottoms produced in methyl ester refining are added to any suitable asphalt composition or cement, for example, industrial asphalts used for coatings, sealants, roofing materials, adhesives, and other applications. However, paving grade asphalts are used in the preferred embodiment of the invention. The asphalt feed composition will determine the amount of ester bottoms required.

(12) Referring now to FIG. 2, there is illustrated a comparison of heavy vacuum gas oil modified asphalt compared with ester bottoms modified asphalt. It can be seen in FIG. 2 that, at similar points, the ester bottoms modified asphalt produces a PG73-23 (UTR=96) versus a HVGO PG71-23 (UTR=94). Similarly, the higher the quantity of modifiers in the asphalt, the ester bottoms produce PG66-29 (UTR=95) versus an HVGO PG63-29 (UTR=92). The ester bottoms modified asphalt presents an improved UTR when compared with HVGO modified asphalts.

(13) The type of asphalt used for the present invention can vary as illustrated by FIGS. 3 and 4. The asphalts may include solvent deasphalting bottoms (SDA). FIGS. 3 and 4 illustrate testing which was done on a PG64-22 (Sample A), PG64-22 (Sample B), and two SDA blends (Samples C and D), and two stiff vacuum tower bottoms blends (Samples E and F). For instance, asphalt from two different refineries (Samples A&B), mixed with 3% ester bottoms resulted in different end products. Similarly, ester bottoms added to SDA or coker feeds affect the finished products differently. Therefore, the weight percentage of ester bottoms required for blending is determined by the asphalt composition.

EXAMPLE 1

(14) Referring now to FIG. 4 a conventional PG 64-22 (Sample A) is used. The control sample at high temperature is approximately 65° C., and the low temperature compliance is actually −25° C. Ester bottoms are added to the Sample A and the resulting product has a high temperature compliance of 60.1° C. and a low temperature compliance of −29.6° C. The useable temperature range of the control equals 86° C. whereas the ester modified composition has a useable temperature range of 89.7° C.

EXAMPLE 2

(15) Referring to FIG. 4, Sample B PG 64-22 has an initial high temperature control of 67.7° C. and the low temperature control is −24.6° C. resulting in a UTR of 92.3. After the addition of 3% ester bottoms the high temperature compliance is 62.4° C. and the low temperature compliance is −29.9° C. resulting in a useable temperature range of 93.2° C., while lowering the lower temperature compliance significantly.

EXAMPLE 3

(16) Referring again to FIG. 4, Samples C & D, SOA blends, were tested. Sample C having a high temperature compliance of 67.7° C. and a low temperature compliance of −18° C. Ester bottoms were added in the amount of 2.25% and 5.77%. The 2.25% ester bottoms addition resulted in a UTR of 87.8° C., while the 5.77% ester bottoms addition resulted in a UTR 89° C. In the Sample D test the 3.70% ester bottoms addition resulted in an 89.8° C. UTR and a 7.1% ester bottoms addition resulted in an 88.8° C. UTR.

(17) It can be seen from FIGS. 2-4 that ester bottoms modified asphalts are at least as good as, if not better at maintaining a UTR than the more expensive HVGO and SDA modified asphalts.

(18) Referring now to FIG. 5, tensile strength testing was employed against three SDA modified binders (1, 2, 3) in comparison with an ester bottoms modified binder (4). Moisture sensitivity results for the three SDA modified PG64-22 asphalts and the ester bottoms modified blend show that the ester bottoms modified blend competed very well against binders 1, 2 and 3. Both dry and wet strains are very strong. During this test a disk-shaped sample of the binder is pulled apart to measure the crack initiation and propagation. By measuring the area under the load and the displacement curve, fracture energy is calculated for the sample. This test provides an understanding of a mixture's ability to resist cracking at both low and intermediate temperatures.

(19) Referring now to FIG. 6 the results of a rutting resistance test, known as the Hamburg Wheel Test, compares binders 1, 2 and 3 against ester modified binder 4. Again, the ester modified binder 4 performs favorably when compared to the other refinery produced PG64-22. The test is performed by repeatedly tracking a loaded wheel over samples in heated bath water. The deformation of the samples versus the number of passes is observed. The Hamburg Wheel Test is used to measure both rutting and stripping risks.

(20) Referring now to FIG. 7 the results of a Disk Shaped Compaction Tension test (DCT) are shown. The DCT is a measure of low temperature and reflective cracking. Binder 4 with the ester bottoms additive was compared against binders 2 and 3. Binder 4 again provided results equal and favorable to the refinery binders. During this test, one set of samples is tested as it exists. For this test, two sets of each binder are tested. One set of the mixed binders are tested as is under dry conditions. The second set of test binders is put through a freeze/fall cycle and is then conditioned in water. The strength for each mix is measured from the load required to crack the sample. The reported number of this graph is the strength ratio of the wet versus dry condition. This strength ratio provides information regarding the moisture susceptibility of the asphalt mix.

(21) FIG. 8 provides the results of a Semi Circular Bend test against binder 2, binder 3 and binder 4 with ester bottoms. This test provides an indicator of resistance to crack propagation and predicts fracture performance. The test shows that binder 4 with ester bottoms additive performed better than binders 2 and 3. The test is performed by 3 point bending of a semi-circular shaped specimen with an introduced notch. This induces tension at the bottom of the sample, resulting in crack propagation throughout the specimen. The energy required to fracture the sample is calculated. The test is run at normal temperatures.

(22) The above detailed description of the present invention is given for explanatory purposes. It will be apparent to those skilled in the art that numerous changes and modifications can be made without departing from the scope of the invention. Accordingly, the whole of the foregoing description is to be construed in an illustrative and not a limitative sense, the scope of the invention being defined solely by the appended claims.