IMPROVED ALKYL ESTATE-CONTAINING OIL COMPOSITIONS AND METHOD FOR THEIR MANUFACTURE AND USE
Patent Information
- Application Number
- DE602017093179
- Authority / Receiving Office
- DE · DE
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2017-05-24
- Publication Date
- 2025-12-17
- Estimated Expiration
- 2037-05-24
AI Technical Summary
Recycled asphalt in pavement and shingles is often very stiff and viscous which can cause premature cracking due to lack of durability as well as loss of workability in its use.
[0007]Recycled asphalt in pavement and shingles is often very stiff and viscous which can cause premature cracking due to lack of durability as well as loss of workability in its use. Recycled asphalt can be rejuvenated by reducing the viscosity, softening, and increasing the durability of asphalt mixtures by addition of corn oil enhanced with fatty acid esters such as ethyl esters (FAEE). Additionally, such a material can be used to modify the grade of various performance grade (PG) asphalts in order to improve the low temperature properties. High ethyl ester containing corn oil is shown here to rejuvenate recycled asphalt and improve low temperature properties of virgin asphalt in the aforementioned ways better than corn oil with a lower ethyl ester content.
Description
Background
[0001] Ethanol can be produced from grain-based feedstocks (e.g., corn, sorghum / milo, barley, wheat, soybeans, etc.), from sugar (e.g., sugar cane, sugar beets, etc.), or from biomass (e.g., lignocellulosic feedstocks, such as switchgrass, corn cobs and stover, wood, or other plant material).
[0002] In a conventional ethanol plant, corn is used as a feedstock and ethanol is produced from starch contained within the corn. Corn kernels are cleaned and milled to prepare starch-containing material for processing. Corn kernels can also be fractionated to separate the starch-containing material (e.g., endosperm) from other matter (such as fiber and germ). The starch-containing material is slurried with water and liquefied to facilitate saccharification, where the starch is converted into sugar (e.g., glucose), and fermentation, where the sugar is converted by an ethanologen (e.g., yeast) into ethanol. The fermentation product is beer, which comprises a liquid component, including ethanol, water, and soluble components, and a solids component, including unfermented particulate matter (among other things). The fermentation product is sent to a distillation system where the fermentation product is distilled and dehydrated into ethanol. The residual matter (e.g., whole stillage) comprises water, soluble components, oil, and unfermented solids (e.g., the solids component of the beer with substantially all ethanol removed, which can be dried into dried distillers grains (DDG) and sold, for example, as an animal feed product). Other co-products (e.g., syrup and oil contained in the syrup), can also be recovered from the whole stillage. Water removed from the fermentation product in distillation can be treated for re-use at the plant.
[0003] Various processes for recovering oil from a fermentation product are currently known in the art. Such processes, however, can be expensive, inefficient or even dangerous.
[0004] Conventional processes for recovering oil from a fermentation product can sacrifice oil quality such that the oil contains a high level of free fatty acids. The presence of a high level of free fatty acids can hamper the production of end products. Processes for producing ethanol, such as the process set forth in WO 2004 / 081193, produce fermentation byproducts which contain increased levels of oils while maintaining a low level of free fatty acids.Summary
[0005] The disclosure provides the use of a corn oil composition comprising corn oil having a fatty acid ethyl ester content that is greater than 7% w / w based on the total weight of the oil composition in an asphalt binder blend composition comprising the corn oil, recycled asphalt and optionally virgin asphalt or in an asphalt mix composition comprising the corn oil and virgin asphalt, the corn oil being for use in an amount that is effective to alter one or more properties of the asphalt binder blend composition or asphalt mix composition relative to a corresponding composition that lacks the corn oil composition, wherein the one or more properties include viscosity, ΔTc value, rutting or thermal cracking; and wherein the corn oil is for use in an asphalt binder blend composition in which the corn oil is 0.5 wt% to 25 wt% of the asphalt or wherein the corn oil is for use in an asphalt mix composition in which the corn oil is 0.5 wt % to 25 wt % of the weight of the asphalt (bitumen without aggregates).
[0006] The corn oil may comprise a lower alkyl ester (methyl, ethyl, propyl or butyl ester, or any combination thereof) content that is greater than 7%, e.g., a lower alkyl ester content that is greater than 18%, w / w based on the total weight of the oil composition and optionally one or more of: an iodine value of not greater than 125 and / or a combined moisture and insoluble content of no greater than 1.5% w / w based on the total weight of the composition; and also optionally a further component selected from the group consisting of: a lutein content of at least 50 mcg / g, a cis-lutein / zeaxanthin content of at least 10 mcg / g, an alpha-cryptoxanthin content of at least 5 mcg / g, a beta-cryptoxanthin content of at least 5 mcg / g, an alpha-carotene content of at least 0.5 mcg / g, and a cis-beta-carotene content of at least 0.1 mcg / g. In one embodiment, the corn oil comprises a free fatty acid content of no greater than 5% w / w based on the total weight of the oil composition. In one embodiment, the corn oil comprises at least one fatty acid selected from the group consisting of C16 palmitic, C18 stearic, C18-1 oleic, C18-2 linoleic, and C18-3 linolenic. In one embodiment, the oil composition further comprises an unsaponifiables content of no greater than 3% w / w based on the total weight of the composition. In one embodiment, the oil composition further comprises an unsaponifiables content of no greater than 2.5% w / w based on the total weight of the composition. In one embodiment, the further component comprises a lutein content of at least 50 mcg / g, a zeaxanthin content of at least 30 mcg / g, a cis-lutein / zeaxanthin content of at least 10 mcg / g, an alpha-cryptoxanthin content of at least 5 mcg / g, a beta-cryptoxanthin content of at least 5 mcg / g, an alpha-carotene content of at least 0.5 mcg / g, a beta-carotene content of at least 1 mcg / g, a cis-beta-carotene content of at least 0.1 mcg / g, an alpha-tocopherol content of at least 50 mcg / g, a beta-tocopherol content of at least 2 mcg / g, a gamma-tocopherol content of at least 300 mcg / g, a delta-tocopherol content of at least 15 mcg / g, an alpha-tocotrienol content of at least 50 mcg / g, a beta-tocotrienol content of at least 5 mcg / g, a gamma-tocotrienol content of at least 80 mcg / g, a delta-tocotrienol content of at least 5 mcg / g, or any combination thereof. In one embodiment, the lower alkyl ester content is greater than about 20% w / w in the total weight of the oil composition. In one embodiment, the lower alkyl ester content is greater than about 30% w / w in the total weight of the oil composition. In one embodiment, the lower alkyl ester content is greater than about 40% w / w in the total weight of the oil composition. In one embodiment, the lower alkyl ester content is greater than about 50% w / w in the total weight of the oil composition. In one embodiment, the lower alkyl ester content is greater than about 60% w / w in the total weight of the oil composition. In one embodiment, the lower alkyl ester content is greater than about 70% w / w in the total weight of the oil composition. In one embodiment, the lower alkyl ester content is greater than about 80% w / w in the total weight of the oil composition. In one embodiment, the oil composition is a fuel composition. In one embodiment, the oil composition is a fuel additive. In one embodiment, the oil composition is an asphalt rejuvenator. In one embodiment, the oil composition is an asphalt performance enhancer.
[0007] Recycled asphalt in pavement and shingles is often very stiff and viscous which can cause premature cracking due to lack of durability as well as loss of workability in its use. Recycled asphalt can be rejuvenated by reducing the viscosity, softening, and increasing the durability of asphalt mixtures by addition of corn oil enhanced with fatty acid esters such as ethyl esters (FAEE). Additionally, such a material can be used to modify the grade of various performance grade (PG) asphalts in order to improve the low temperature properties. High ethyl ester containing corn oil is shown here to rejuvenate recycled asphalt and improve low temperature properties of virgin asphalt in the aforementioned ways better than corn oil with a lower ethyl ester content.
[0008] Further provided is a method to alter one or more properties of asphalt, e.g., recycled asphalt, virgin asphalt or performance-grade asphalt. The method includes in one embodiment combining recycled asphalt, performance-grade asphalt, or recycled asphalt and virgin asphalt, and an amount of a corn oil composition effective to alter at least one property of the asphalt, thereby forming an asphalt mix composition (if aggregates are present, e.g., from the recycled asphalt), or an asphalt binder blend composition (if aggregates are absent), wherein the corn oil has a lower alkyl ester content that is greater than 7%, e.g., ester content that is greater than 18%, w / w based on the total weight of the oil composition. Optionally the corn oil has an iodine value of not greater than 125 and / or a combined moisture and insoluble content of no greater than 1.5% w / w based on the total weight of the composition; and also optionally a further component selected from the group consisting of: a lutein content of at least 50 mcg / g, a cis-lutein / zeaxanthin content of at least 10 mcg / g, an alpha-cryptoxanthin content of at least 5 mcg / g, a beta-cryptoxanthin content of at least 5 mcg / g, an alpha-carotene content of at least 0.5 mcg / g, and a cis-beta-carotene content of at least 0.1 mcg / g. In one embodiment, the corn oil has a free fatty acid content of no greater than 5% w / w based on the total weight of the composition. In one embodiment, the free fatty acid content of the oil composition comprises at least one fatty acid selected from the group consisting of C16 palmitic, C18 stearic, C18-1 oleic, C18-2 linoleic, and C18-3 linolenic. In one embodiment, the oil composition further comprises an unsaponifiables content of no greater than 3% w / w based on the total weight of the composition. In one embodiment, the oil composition further comprises an unsaponifiables content of no greater than 2.5% w / w based on the total weight of the composition. In one embodiment, the lower alkyl ester content is greater than about 30% w / w in the total weight of the oil composition. In one embodiment, the lower alkyl ester content is greater than about 50% w / w in the total weight of the oil composition. In one embodiment, the lower alkyl ester content is greater than about 20% w / w in the total weight of the oil composition. In one embodiment, the lower alkyl ester content is greater than about 60% w / w in the total weight of the oil composition. In one embodiment, the oil composition is about 0.5% w / w to about 50% w / w the total weight of the bitumen without aggregates (referred to as an asphalt binder composition), or a combined weight of the bitumen and the oil composition (an asphalt binder blend). In one embodiment, the oil composition is about 1% w / w to about 50% w / w the total weight of the asphalt binder composition, or a combined weight of the asphalt binder composition and the oil composition. In one embodiment, the oil composition is about 1% w / w to about 25% w / w the total weight of the asphalt binder composition or a combined weight of the asphalt binder composition and the oil composition. In one embodiment, the oil composition is about 1% w / w to about 10% w / w the total weight of the asphalt binder composition, or a combined weight of the asphalt binder composition and the oil composition.
[0009] Also provided is an asphalt binder blend composition comprising a bitumen composition (without aggregates; an asphalt binder composition) and a corn oil composition having a lower alkyl ester content that is greater than 7%, e.g., an ethyl ester content that is greater than 18%, w / w based on the total weight of the oil composition; and optionally an iodine value of not greater than 125 and / or a combined moisture and insoluble content of no greater than 1.5% w / w based on the total weight of the composition; and also optionally a further component selected from the group consisting of: a lutein content of at least 50 mcg / g, a cis-lutein / zeaxanthin content of at least 10 mcg / g, an alpha-cryptoxanthin content of at least 5 mcg / g, a beta-cryptoxanthin content of at least 5 mcg / g, an alpha-carotene content of at least 0.5 mcg / g, and a cis-beta-carotene content of at least 0.1 mcg / g. In one embodiment, the corn oil is about 0.5 wt % to about 25 wt % of the weight of the asphalt binder composition (bitumen without aggregates), or a combined weight of the asphalt binder composition and the oil composition. In one embodiment, the corn oil is about 4 wt % to about 12 wt % of weight of the bitumen composition (without aggregates), or a combined weight of the asphalt binder composition and the oil composition (asphalt binder blend). In one embodiment, the corn oil is about 5 wt % to 10 wt % of the weight of the of the asphalt binder composition (bitumen without aggregates), or a combined weight of the asphalt binder composition and the oil composition. In one embodiment, the corn oil is about 0.5 wt % to about 50 wt % of the weight of the asphalt binder composition, or a combined weight of the asphalt binder composition and the oil composition. In one embodiment, the corn oil is about 1 wt % to about 25 wt % of the weight of the of the asphalt binder composition (bitumen without aggregates), or a combined weight of the asphalt binder composition and the oil composition. In one embodiment, the lower alkyl ester content is greater than about 18% and up to about 80% w / w in the total weight of the oil composition. In one embodiment, the lower alkyl ester content is greater than about 20% up to about 60% w / w in the total weight of the oil composition. In one embodiment, the lower alkyl ester content is greater than about 30% and up to about 50% w / w in the total weight of the oil composition. In one embodiment, the corn oil has a free fatty acid content of no greater than 5% w / w based on the total weight of the oil composition. In one embodiment, the asphalt comprises recycled asphalt. In one embodiment, the asphalt comprises virgin asphalt. In one embodiment, the asphalt comprises performance grade asphalt. In one embodiment, the asphalt comprises recycled asphalt. In one embodiment, the asphalt binder composition comprises an emulsion, e.g., which also includes water and an emulsifier.
[0010] Further provided is a pavement or paving composition (asphalt mix) comprising aggregate, e.g., virgin aggregate, and from about 1.0% to about 10.0% of an asphalt binder composition and a corn oil composition having: a lower alkyl ester content that is greater than about 7%, such as greater than 18%, w / w based on the total weight of the composition; and optionally an iodine value of not greater than 125 and / or a combined moisture and insoluble content of no greater than 1.5% w / w based on the total weight of the composition; and also optionally a further component selected from the group consisting of: a lutein content of at least 50 mcg / g, a cis-lutein / zeaxanthin content of at least 10 mcg / g, an alpha-cryptoxanthin content of at least 5 mcg / g, a beta-cryptoxanthin content of at least 5 mcg / g, an alpha-carotene content of at least 0.5 mcg / g, and a cis-beta-carotene content of at least 0.1 mcg / g. Methods of making a paving composition are also provided. In one embodiment, the lower alkyl ester content is greater than about 20% and up to about 60% w / w in the total weight of the oil composition. In one embodiment, the lower alkyl ester content is greater than about 30% up to about 50% w / w in the total weight of the oil composition. In one embodiment, the lower alkyl ester content is greater than about 30% and up to about 70% w / w in the total weight of the oil composition. In one embodiment, the corn oil has a free fatty acid content of no greater than 5% w / w based on the total weight in the oil composition.
[0011] In addition, an asphalt mix composition is provided comprising: bitumen, aggregate and a corn oil composition having a lower alkyl ester content that is greater than 7%, e.g., greater than about 18%, w / w based on the total weight of the oil composition; and optionally an iodine value of not greater than 125 and / or a combined moisture and insoluble content of no greater than 1.5% w / w based on the total weight of the composition; and also optionally a further component selected from the group consisting of: a lutein content of at least 50 mcg / g, a cis-lutein / zeaxanthin content of at least 10 mcg / g, an alpha-cryptoxanthin content of at least 5 mcg / g, a beta-cryptoxanthin content of at least 5 mcg / g, an alpha-carotene content of at least 0.5 mcg / g, and a cis-beta-carotene content of at least 0.1 mcg / g. In one embodiment, the lower alkyl ester content in the corn oil is greater than about 20% and up to about 60% w / w in the total weight of the oil composition. In one embodiment, the lower alkyl ester content in the corn oil is greater than about 30% up to about 70% w / w in the total weight of the oil composition. In one embodiment, the lower alkyl ester content in the corn oil is greater than about 40% and up to about 80% w / w in the total weight of the oil composition. In one embodiment, the corn oil has a free fatty acid content of no greater than 5% w / w based on the total weight of the composition. In one embodiment, the aggregate comprises a plurality of solids comprising sand, gravel, crushed stone, crushed concrete, crushed glass, industrial slag, or any combination thereof. In one embodiment, the asphalt mix is a combination of virgin asphalt and recycled asphalt. In one embodiment, the corn oil is about 0.5 wt % to about 25 wt % of the weight of the asphalt binder composition (bitumen without aggregates), or a combined weight of the asphalt binder composition and the oil composition. In one embodiment, the corn oil is about 4 wt % to about 12 wt % of weight of the asphalt binder composition (bitumen without aggregates), or a combined weight of the asphalt binder composition and the oil composition. In one embodiment, the corn oil is about 5 wt % to 10 wt % of the weight of the asphalt binder composition , or a combined weight of the asphalt binder composition and the oil composition. In one embodiment, the corn oil is about 0.5 wt % to about 50 wt % of the weight of asphalt binder composition, or a combined weight of the asphalt binder composition and the oil composition.Brief Description of the Figures
[0012] Figure 1 is a schematic block flow diagram of a process for producing ethanol from corn. Figure 2 is a schematic flow diagram of a process for producing ethanol from corn. Figure 3 shows the effect of pH on the fatty acid content of the oil composition. Figure 4 shows an exemplary process flow diagram. Figures 5A-E show various exemplary flow diagrams for providing the oil composition and the distillers dried grains. Figure 6 shows that conventional ethanol fermentation including a liquefaction step prior to fermentation decreases the ethyl ester content of the extracted oil post fermentation compared to a control corn composition (BPX). N = 5 fermentations for both conventional and BPX. Figure 7 shows that addition of lipase at the beginning of BPX fermentation increases the level of FAEE in corn oil extracted at the end of fermentation. The various enzyme doses of control (0.0%), 0.04%, 0.4%, and 4.0% are based upon lipase weight added to weight of corn fat available in the fermenter. Each dose was performed in duplicate. Figure 8 shows that reduction of viscosity as a function of ethyl ester content in corn oil. The dynamic viscosity of corn oil at 25°C is reduced as ethyl ester concentration is increased. Data was obtained with a Brookfield viscometer. Figure 9 shows that effect of corn oil rejuvenators with 3% and 100% ethyl esters (EE) content on ΔT c of aged asphalt. An increase in ΔT c is favorable and is a measure of the relative durability of the asphalt. Values were obtained from the bending beam rheometer test (AASHTO T313). Figure 10 shows performance grade tests demonstrating modification of a 64-22 asphalt to a 58-28 and 52-34 with 4 and 7 percent inclusion of distiller's corn oil (DCO), respectively. Figure 11 shows that DCO at 4 percent inclusion significantly increases the cracking resistance of the asphalt mixture containing 50% RAP. Tests were carried out by overlay tester (TxDOT Tex-248-F). Figure 12 shows the effect on rutting by inclusion of 4 percent DCO in a 50% RAP mixture compared to 50% RAP control. Line shown on graph indicates the maximal rutting specification of 12.5 mm over 10,000 wheel passes. Tests were carried out by Hamburg Wheel Track (AASHTO T-324). Detailed Description
[0013] This disclosure relates to a vegetable oil, e.g., corn oil, composition with enhanced lower alkyl ester content and a method for producing the same, as well as the use of vegetable oil, e.g., corn oil, compositions, for example, to enhance the properties of performance grade or rejuvenated asphalt.
[0014] It must be noted that as used herein and in the appended claims, the singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "an alkali metal ion" includes a plurality of alkali metal ions.Definitions
[0015] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. As used herein the following terms have the following meanings.
[0016] As used herein, the term "comprising" or "comprises" is intended to mean that the compositions and methods include the recited elements, but not excluding others. "Consisting essentially of" when used to define compositions and methods, shall mean excluding other elements of any essential significance to the combination for the stated purpose. Thus, a composition consisting essentially of the elements as defined herein would not exclude other materials or steps that do not materially affect the basic and novel characteristic(s) of the claimed invention. "Consisting of shall mean excluding more than trace elements of other ingredients and substantial method steps. Embodiments defined by each of these transition terms are within the scope of this invention.
[0017] As used herein, the term "about" modifying any amount refers to the variation in that amount encountered in real world conditions of producing sugars and ethanol, e.g., in the lab, pilot plant, or production facility. For example, an amount of an ingredient employed in a mixture when modified by "about" includes the variation and degree of care typically employed in measuring in an ethanol production plant or lab. For example, the amount of a component of a product when modified by "about" includes the variation between batches in an ethanol production plant or lab and the variation inherent in the analytical method. Whether or not modified by "about," the amounts include equivalents to those amounts. Any quantity stated herein and modified by "about" can also be employed in the present invention as the amount not modified by "about." For instance, the term "about" when used before a numerical designation, e.g., temperature, time, amount, and concentration, including range, indicates approximations which may vary by (+) or (-) 10%, 5% or 1%.
[0018] As used herein, the term "unrefined vegetable oil" refers to vegetable oil which has not been subjected to a refining process, such as alkali refining or physical refining (i.e., distillation, deodorization, bleaching, etc.).
[0019] As used herein, the term "free fatty acid" (FFA) refers to an unesterified fatty acid, or more specifically, a fatty acid having a carboxylic acid head and a saturated or unsaturated unbranched aliphatic tail (group) of from 4 to 28 carbons. The term "aliphatic" has it generally recognized meaning and refers to a group containing only carbon and hydrogen atoms which is straight chain, branched chain, cyclic, saturated or unsaturated but not aromatic. In contrast, a fatty acid ester, such as a fatty acid ethyl ester (FAEE), is an esterified (not free) fatty acid. For example, FAEE is a fatty acid esterified with ethanol.
[0020] As used herein, the term "moisture content" refers to the amount of water and other soluble components in the oil composition. The moisture in the vegetable oil composition contains the alkali and / or alkaline metal, and may contain other soluble components, such as volatile material including hexane, ethanol, methanol, and the like.
[0021] As used herein, the term "an alkali metal ion" refers to one or more metal ion of Group 1 of the periodic table (e.g., lithium (L +< ), sodium (Na +< ), potassium (K +< ), etc.).
[0022] As used herein, the term "an alkaline metal ion" refers to a metal ion of Group 2 of the periodic table (e.g., magnesium (Mg 2+< ), calcium (Ca 2+< ), etc.).
[0023] As used herein, the term "insoluble" refers to material in the oil which is not solvated by the aqueous portion, the oil or the moisture content within the oil.
[0024] As used herein, the term "unsaponifiables" refers to components of the oil that do not form soaps when blended with a base, and includes any variety of possible non-triglyceride materials. This material can act as contaminants during biodiesel production. Unsaponifiable material can significantly reduce the end product yields of the oil composition and can, in turn, reduce end product yields of the methods disclosed herein.
[0025] As used herein, the term "peroxide value" refers to the amount of peroxide oxygen (in millimoles) per 1 kilogram of fat or oil and is a test of the oxidation of the double bonds of the oils. The peroxide value is determined by measuring the amount of iodine (I -< ) via colorimetry which is formed by the reaction of peroxides (ROOH) formed in the oil with iodide via the following equation: 2 I -< +H 2 O+ROOH->ROH+20H -< +I 2 .
[0026] As used herein, the term "oxidative stability index value" refers to the length of time the oil resists oxidation at a given temperature. Typically, the oxidation of oil is slow, until the natural resistance (due to the degree of saturation, natural or added antioxidants, etc.) is overcome, at which point oxidation accelerates and becomes very rapid. The measurement of this time is the oxidative stability index value.
[0027] As used herein, the term "vegetable fermentation residue" refers to the residual components of a vegetable fermentation process after the ethanol has been recovered, typically via distillation. Typically, the vegetable fermentation residue comprises water, any residual starch, enzymes, etc.
[0028] As used herein, the term "syrup" refers to the viscous composition which is provided by the evaporation of the thin stillage.
[0029] As used herein, the term "base" refers to a compound or composition which raises the pH of an aqueous solution. Suitable bases for use in this invention include, but are not limited to, sodium hydroxide, potassium hydroxide, calcium hydroxide, or spent alkali wash solution.
[0030] As used herein, the term "alkali wash solution" refers to the basic solution which is used to disinfect the fermentor after the fermentation process has been completed. The alkali wash solution typically comprises sodium hydroxide.
[0031] As used herein, the phrase "without cooking" refers to a process for converting starch to ethanol without heat treatment for gelatinization and dextrinization of starch using alpha-amylase. Generally, for the process of the present invention, "without cooking" refers to maintaining a temperature below starch gelatinization temperatures, so that saccharification occurs directly from the raw native insoluble starch to soluble glucose while bypassing conventional starch gelatinization conditions. Starch gelatinization temperatures are typically in a range of 57°C to 93°C depending on the starch source and polymer type. In the method of the present invention, dextrinization of starch using conventional liquefaction techniques is not necessary for efficient fermentation of the carbohydrate in the grain.
[0032] As used herein, the phrase "plant material" refers to all or part of any plant (e.g., cereal grain), typically a material including starch. Suitable plant material includes grains such as maize (corn, e.g., whole ground corn), sorghum (milo), barley, wheat, rye, rice, and millet; and starchy root crops, tubers, or roots such as sweet potato and cassava. The plant material can be a mixture of such materials and byproducts of such materials, e.g., corn fiber, corn cobs, stover, or other cellulose and hemicellulose containing materials such as wood or plant residues. Suitable plant materials include corn, either standard corn or waxy corn.
[0033] In one embodiment, an asphalt binder blend composition is provided containing a corn oil composition disclosed herein and virgin asphalt or an asphalt mix composition containing a corn oil composition disclosed herein and asphalt material containing recycled asphalt. The addition of a corn oil composition to virgin asphalt is referred to as "asphalt modification", whereas addition of a corn oil composition to an asphalt material containing recycled asphalt, such as recycled asphalt pavement (RAP) or recycled asphalt shingles (RAS) which may contain aggregates, is referred to as "asphalt rejuvenation". An asphalt binder blend containing virgin asphalt includes corn oil containing in one embodiment less than 5% free fatty acid (FFA) and between about, for example, greater that about 18% fatty acid lower alkyl esters, about 20 to about 40% lower alkyl esters, or about 40 to about 80% or more lower alkyl esters, by weight of the corn oil. An asphalt mix containing recycled asphalt includes in one embodiment corn oil containing in one embodiment less than 5% free fatty acid (FFA) and between about, for example, greater than about 18% fatty acid lower alkyl esters, about 20 to about 40% fatty acid lower alkyl esters, or about 40 to about 80% or more fatty acid lower alkyl esters, by weight of the corn oil. The binder blend or asphalt mix may also contain other asphalt modifiers including, but not limited to, various petroleum fractions, polymers, polyphosphoric acid, lime, waxes, and / or antistrip agents. The range of inclusion of DCO into asphalt is 1% to 25% by weight of the total binder blend.
[0034] The virgin or recycled asphalt can have a range of viscosity, penetration, stiffness, and viscoelastic properties that result in Superpave performance grades (PGs) ranging from a high temperature of 46°C to 172°C and a low temperature from -46°C to 2°C. The final PG of the resulting binder blend containing the asphalt, corn oil composition, and other modifiers can range in a high temperature from 46°C to 82°C and a low temperature ranging from -46°C to -10°C. The blending of a corn oil composition with recycled asphalt should increase the ΔT c , which is decreased during the aging process indicating a loss in asphalt durability. The ΔT c is defined as the difference between the continuous stiffness temperature and continuous relaxation temperature as measured by the bending beam rheometer (BBR) test (AASHTO T313).
[0035] For asphalt modification of virgin asphalt, the amount of a corn oil composition added in the final binder blend is dependent on the properties of the virgin asphalt. A stiffer asphalt, defined as having a large G* complex modulus (AASHTO T315), would require a higher inclusion of DCO or a DCO with higher fatty acid lower alkyl ester content. For example, a refining residue with a G* of 30.08 kPa at 64°C requires 10% inclusion of DCO to reduce it to 1.07 kPa at the same measuring temperature. A virgin asphalt with a G* value of 1.21 kPa at 64°C can be blended with 4% inclusion of DCO to reduce the G* value to 0.57 kPa at the same temperature. As a result of the modification, the low temperature property of the binder blend is improved as well. The binder blend low temperature is determined by the stiffness and m-value measured by the BBR test.
[0036] A corn oil composition can also be used in asphalt rejuvenation of recycled asphalt present in RAP and RAS. As asphalt is aged, the binder becomes oxidized and hardens decreasing the ΔT c value indicating a loss of durability. In order to rejuvenate aged asphalt, a corn oil composition can be added to the recycled asphalt in order to increase the ΔT c value. In addition, inclusion of a corn oil composition increases the mix performance of RAP blends as observed as an increase in both low and intermediate cracking resistance without causing the mix to become susceptible to rutting. Typical inclusion of RAP in asphalt mixes may range from 1% to 50%. Inclusion of a corn oil composition in RAP containing asphalt mixes may range from 1% to 25% based upon the weight of the asphalt binder blend composition. For a hot mix, RAP or RAS can be rejuvenated by several different methods. A corn oil composition can be added onto the RAP or RAS stockpiles, added directly into the mix drum, or injected into the virgin asphalt. RAP / RAS can be pretreated by spraying the stream prior to its addition to the mix drum. A corn oil composition can also be added to virgin asphalt in storage tanks equipped with mixers or it can be added with an in-line static mixer downstream prior to reaching the mix drum.
[0037] The pH level capable of providing an oil composition containing a low level of free fatty acid can be determined (Figure 3). First, an oil fraction in the form of an emulsion separated from fermented product may be adjusted to the pH levels of 7.7, 7.9, 8.0, 8.1, 8.2, and 8.3. The samples may then be centrifuged to separate the oil composition and the oil composition was analyzed for free fatty acid content.
[0038] In summary, those samples tested at lower pH (i.e., below 8.0) exhibited free fatty acid contents above 3.5% w / w while those tested at a pH above 8.1 exhibited a free fatty acid content of below 2% w / w. TABLE 1pH7.77.98.08.18.28.3Free Fatty Acids (percent)3.52.22.02.22.01.8Experiment 1Free Fatty Acids (percent)4.83.53.12.22.01.8Experiment 2
[0039] A series of oil fractions, in the form of emulsions samples previously separated by a first application of a centrifugal force were treated with NaOH to adjust the pH to various levels as shown in Table 2. Each sample contained the same amount of oil before adjusting the pH. After adjusting the pH to the targeted value, the volume of free oil was measured.
[0040] A pH at about 8.2 may result in the highest value of free oil volume. The volume of free oil was shown to increase up to this value and then deteriorate thereafter. Thus, an optimum pH for separation exists for each oil fraction sample. TABLE 2pH7.07.47.88.08.28.48.89.210.0Free Fatty Acids (percent)1.03042456048504543Experiment 1
[0041] Experiments may be conducted to demonstrate that the combination of adjusting the pH and applying a centrifugal force resulted in (a) higher quality corn oil compositions and (b) higher corn oil composition yield compared to those oil compositions obtained upon application of a centrifugal force alone. The free fatty acid content may be shown to be reduced by up to 3% by adjusting the pH in combination with centrifugal force as opposed to centrifugal force alone. The yield of separated oil composition may be increased by 140%. The experiment was run for about 30 days, and includes 3 daily samples.
[0042] A compositional analysis of the products obtained from one embodiment of the system may be performed. The syrup fraction obtained from the ethanol production process may be centrifuged to separate into a light fraction (emulsified oil) and a heavy fraction (stickwater). The syrup obtained may be mostly free of oil. The heavy fraction may be returned to the normal process to be further evaporated and added to wet cake and dried.
[0043] The pH of the light fraction may be raised to approximately 8.2 from a pH of approximately 3.5. The pH adjusted emulsified material may be fed to a second centrifuge step. The heavy fraction (soapstock) from the second centrifuge step may be high in soaps and proteins and may be mixed with the stickwater and added to the wet cake and dried. The light fraction from the second centrifuge may be oil. The oil may exhibit a high quality and low free fatty acid content, insolubles, moisture, phospholipids and unsaponifiables. The oil may be used with or without further refining. The distiller's dried grains composition projected to result from the combination of wet cake, soapstock, and low fat syrup may exhibit lower fat and higher protein than typical for distillers dried grain. TABLE 3Fat (percent)Protein (percent)Moisture (percent)Other (percent)***Starting Material*5.44.18010First Light Fraction (Emulsified Oil)*353.6556.8First Heavy Fraction (Stickwater)*3.54.28310Second Light Fraction (Oil Composition)*980.00.81.6Second Heavy Fraction (Soapstock)*5.55.97711Low Fat DDGS**4.0308.757*= Sampled, **= Projected, ***= Includes fiber, ash, starch, etc.
[0044] In a conventional dry-grind ethanol process, whole corn is ground to a flour, mixed with water and cooked at a high temperature to gelatinize the starch and to make it more available for subsequent liquefaction and saccharification by enzymes. The cooked mash is then cooled to facilitate fermentation of the sugars into ethanol. The resulting beer includes soluble and insoluble components, such as proteins, oil, fiber, residual starch and glycerol. The beer is separated into ethanol and whole stillage in distillation. The whole stillage can be dewatered to produce wet cake by removing a thin stillage component by centrifugation. The oil partitions fairly equally, by weight, between thin stillage and the wet cake. Thin stillage is typically further evaporated into syrup, which can be added back onto the wet cake during a drying process that produces distillers dried grains with solubles (i.e., DDGS). Corn oil can be recovered from the syrup by a simple centrifuging step, as described for example in U.S. Pat. No. 7,601,858.
[0045] Some dry-grind ethanol processing facilities utilize a modified dry grind process known as raw starch ethanol production. In these facilities, the corn is ground to fine flour, mixed with water and enzymes, and fermented to ethanol-containing beer in a simultaneous saccharification and fermentation reaction. The rest of the raw starch process is similar to the conventional process. However, in the raw starch process the oil cannot be separated from the syrup by a simple centrifugation step, but requires an additional treatment step (pH adjustment) and a second centrifugation step to recover the oil. Overall, raw starch ethanol production requires less energy and cooling water.
[0046] Oil extracted from corn DDGS using solvents, and oil extracted centrifugally from thin stillage have similar, or slightly lower concentrations of tocopherols than corn germ oil, but have higher concentrations of phytosterols, tocotrienols, and steryl ferulates, than corn germ oil.
[0047] The following provides exemplary methods and analyses of vegetable oil compositions.Materials and MethodsChemicals
[0048] Dry chemicals (ACS grade or better) were obtained from Sigma-Supelco (St. Louis, Mo.) unless otherwise noted in referenced methods. Solvents were HPLC grade and were obtained from Fisher (Fairlawn, N.J.).Oils
[0049] The five oils that were characterized included hexane Soxhlet extracts of corn germ (CG) and DDGS (DDGS), and three oils that were centrifugally extracted from dry grind ethanol production facilities (CS-1, CS-2, CS-3). The corn germ was obtained from an ethanol production facility that operates a dry fractionation process where the corn kernels are separated into germ, fiber, and endosperm fractions prior to fermentation. Corn DDGS was obtained from a raw starch ethanol production facility operated by POET, LLC (Sioux Falls, S.D.). CG and DDGS were extracted overnight (about 20 hr) by Soxhlet extraction using hexane. Four parallel Soxhlet extractors with about 100 g / thimble were used several days in a row and the extracts were combined to obtain enough oil from the germ and DDGS for analyses and storage studies. Hexane was removed by rotary evaporation at 40°C, oil was then stirred for 4 hours under a high vacuum to remove any excess hexane, after which the oil was put into several amber bottles, topped with argon to prevent lipid oxidation, and frozen at -20°C until used for analyses. CS-1 was obtained from a conventional dry grind ethanol plant. CS-2 and CS-3 were obtained from two different production runs from a raw starch ethanol production facility operated by POET. CS-1, CS-2, and CS-3 were shipped overnight, on dry ice, to the research location, and immediately transferred to glass bottles, topped with argon, and frozen (-20°C) until used for analyses.Oil AnalysisAcid Value
[0050] Acid Value was determined by titration using AOCS official method Cd 3d-63 (AOCS, 1998). The acid value was used to calculate the percent free fatty acids (FFA) as percent oleic acid by dividing the acid value by 1.99 as stated in the method. Each oil was analyzed in triplicate for Acid Value and the mean is reported.Fatty Acid Composition and Iodine Value
[0051] Oil triacylglycerols were transesterified using the method described by Ichihara (1996). Fatty acid methyl esters were analyzed in triplicate by GC. The Iodine Values were calculated based on the fatty acid composition according to the AOCS Method Cd 1c-85 (AOCS, 1998).Tocopherols, Phytosterols, and Steryl Ferulate Analysis
[0052] The contents of tocopherols, tocotrienols, and steryl ferulates were analyzed in triplicate in the crude oils by HPLC with a combination of UV and fluorescence detection as previously described (Winkler et al., 2007). In order to analyze total phytosterol content and composition, the oils were saponified, and the phytosterols were extracted and derivatized as previously described (Winkler et al., 2007). Phytosterols were quantitated by GC as described by Winkler and Vaughn (2009). The identity of phytosterol peaks was confirmed by GC-MS analysis performed on an Agilent (Santa Clara, Calif., USA) 6890 GC-MS equipped with a HP-5MS capillary column (30 m 9 0.25 mm 9 0.25 Im), a 5973 mass selective detector, and an 7683 autosampler. The transfer line from GC to the MSD was set to 280°C. The injector and oven temperature programs were the same as described above for the GC-FID instrument. MSD parameters were as follows: scan mode, 50-600 amu, ionizing voltage, 70 eV, and EM voltage, 1,823 V. Mass spectral identification was performed using the Wiley MS database combined with comparison to literature values for relative RT (compared to β-sitosterol) and mass spectra (Beveridge et al., 2002).Carotenoid Analysis
[0053] Carotenoid analysis and quantitation were conducted by HPLC as described by Winkler and Vaughn (2009).Oxidative Stability Index
[0054] The OSI at 110°C was determined in triplicate following the AOCS Official Method Cd 12b-92 (AOCS, 1998). A Metrohm (Herisau, Switzerland) 743 Rancimat with software control automatically controlled air flow and temperature and calculated the OSI values based on induction time.Accelerated Storage Study
[0055] The study protocol followed AOCS Recommended Practice Cg 5-97 (AOCS, 1998). Oil samples (5 g) were weighed into 40-ml amber glass vials which were loosely capped. For each treatment and day, triplicate vials were prepared. Vials were stored in completely randomized order in a dark oven held at 40±1°C. For each oil, three vials were removed on days one through six and on day eight. CG oil samples were also removed on days 10 and 12. However, as the study progressed, it was determined that the DDGS and CS-2 oils were oxidizing more slowly than the CG oil, so samples were removed on days 12 and 14 order to extend their storage by two more days. Upon removal from the oven, vials were immediately topped with argon, tightly capped, and frozen (-20°C) until analysis. Analyses were conducted either on the same day or within 2 days of removal from the oven. Peroxide values were determined using the method described by Shantha and Decker (1994). Each oil replicate from the storage studies was analyzed in duplicate. Hexanal in the oil headspace of each replicate was quantified in duplicate by solid-phase microextraction (SPME) and GC analysis as described by Winkler and Vaughn (2009).Room Temperature Storage Study
[0056] CS-2 oil was placed into three, 4L amber bottles. Each bottle was filled to the same volume level of 3.4 L. The amount of headspace above the oil samples amounted to 0.9 L. Bottles were tightly capped and stored in the dark at 20°C±3°C, the temperature was monitored daily and the high and low temperature was recorded. Samples were taken once a week for 13 weeks. To sample, bottles were first gently shaken for 30 seconds to mix the contents. Then a glass pipet was inserted into the center of the bottle and 5 ml oil was taken and placed into a screw cap vial, covered with argon, and frozen (-20°C) until analysis. Peroxide value and headspace analysis of hexanal were performed on the oil samples as described above, and were typically run on the same day or within 1-2 days of sampling.Fatty Acid Composition and Free Fatty Acids
[0057] The fatty acid compositions (Table 4) of all five oils were typical for corn oil. The Iodine Values ranged from 122.4 to 124.3. These results concur with other reports that the fatty acid composition of oil extracted from DDGS and thin stillage are similar to corn oil. The two oils (CS-1 and CS-2) that were centrifugally extracted from syrup from the raw starch ethanol production facilities had the lowest % FFA (2.03% and 2.48%, respectively). The oil recovered by centrifugation of syrup from the traditional dry grind ethanol production plant had the highest Acid Value, with 10.1% FFA. Other studies have reported FFA content of oil recovered by centrifugation of thin stillage ranging from 11.2-16.4%. These results indicate that the elimination of the cooking step in the raw starch process reduces the production of FFA. The oil extracted from DDGS using hexane had the second highest acid value (7.42% FFA). Winkler-Moser and Vaughn (2009) reported FFA content of 6.8% (w / w) in hexane Soxhlet extracted DDGS oil, while Moreau et al. (2010) reported FFA content ranging from 8-12% in DDGS that was extracted with hexane using accelerated solvent extraction. FFA content of DDGS extracts has been shown to vary widely depending on the extraction method and conditions and on the solvent used. The DDGS used in this study also came from a raw starch ethanol plant, so it might be expected to have lower FFA. However, high temperatures used to dry the wet grains may have contributed to the increase in FFA. In one experiment, Moreau et al. (2010) demonstrated that oil extracted from thin stillage and distillers dried grains (prior to mixing the grains with the syrup) had high FFA content that carried through to the DDGS. The FFA content of hexane extracted corn germ was 3.8%, which is slightly higher than the average of 2.5% FFA typically found in crude corn germ oil. For biodiesel production, oil with an Acid Value greater than one requires pretreatment because the free fatty acids form soaps during base-catalyzed esterification, which interfere with the separation of the glycerol from the fatty acid methyl esters. Thus, crude oils with lower free fatty acids will have lower oil loss due to the pre-treatment. Free fatty acids decrease the oxidative stability of oils and can also precipitate at ambient temperatures, both of which could negatively impact fuel performance. TABLE 4Acid value, fatty acid composition, and calculated Iodine Value of oils extracted from corn germ (CG), distillers dried grains with soluble (DDGS), and centrifugally extracted thin stillage syrup (CS-1, CS-2, CS-3)CGDDGSCS-1CS-2CS-3Acid Value (mg KOH / g)10.7 ± 0.0720.8 ± 0.3628.3 ± 0.325.70 ± 0.136.88 ± 0.09FFA (% oleic acid)3.80 ± 0.037.42 ± 0.1310.1 ± 0.112.03 ± 0.052.48 ± 0.05Fatty Acid Composition (%)16:013.112.911.512.212.916:10.00.10.10.10.118:01.51.81.71.81.518:129.228.129.328.327.518:255.055.555.655.355.920:00.20.30.30.40.318:31.01.21.171.21.220:10.00.00.20.30.2Calculated Iodine Value122.4123.1124.3123.7124.1 Content and Composition of Tocopherols, Tocotrienols, and Carotenoids
[0058] Tocopherols are common in vegetable oils and are the primary antioxidants protecting most oils. With corn and other plants, the tocopherol and tocotrienol content will vary based upon factors including hybrid, growth conditions, post-harvesting and processing conditions, as well as the type of solvent used for extraction. Therefore, in this study little can be inferred about how processing practices affected tocopherol levels since each production facility and even each production run will have started with different batches of whole corn. Gamma- and alpha-tocopherol were the most prominent homologues detected in all five oils (Table 5), along with a small amount of delta-tocopherol, which is the typical tocopherol profile for corn oil. CG oil had the highest total concentration of tocopherols (1433.6 µg / g oil) followed by the hexane extracted DDGS (1104.2). The levels in the DDGS oil are similar to what was previously reported in hexane extracted DDGS from a conventional dry grind production facility. Tocopherols in corn are localized in the germ portion of the kernel, so the rest of the corn kernel contributes little to the tocopherol content. CS-1, CS-2, and CS-3 were all lower in alpha-tocopherol compared to CG and DDGS oils, but were similar to levels reported in oil extracted centrifugally from thin stillage (Moreau et al., 2010). TABLE 5Content of tocols and carotenoids, and the oxidative stability index (OSI) at 110° C., for oils extracted from corn germ (CG), distillers dried grains with solubles (DDGS), and centrifugally extracted thin stillage syrup (CS-1, CS-2, CS-3)CGDDGSCS-1CS-2CS-3Total Tocopherols (µg / g)1433.61104.21056.9931.3783.4Alpha-tocopherol213.8295.6164.5160.4123.2Gamma-tocopherol1185.4760.8852.7742.0640.0Delta-tocopherol34.347.839.728.820.2Total Tocotrienols (µg / g)235.61762.31419.61224.41175.2Alpha-tocotrienol21.9471.9328.5243.6269.4Gamma-tocotrienol165.61210.01063.6963.4880Delta-tocotrienol48.180.327.517.325.8Total Carotenoids (µg / g)1.3375.02129.4861.185.0Lutein0.3746.6975.6938.1353.7Zeaxanthin0.424.1645.5816.7823.7Beta-cryptoxanthin0.563.317.354.125.1Beta-caroteneNDa0.860.862.072.5OSI (hr)3.916.624.454.525.27 a< Not detected
[0059] Tocotrienols are common in rice bran oil and palm oil, but are not abundant in most commercial vegetable oils. Their antioxidant activity is similar to tocopherols in bulk oil systems, but they also appear to have hypocholesterolemic, anti-cancer, and neuroprotective properties. The post-fermentation corn oils (DDGS, CS-1, CS-2, and CS-3) were higher in tocotrienol concentration compared to CG oil, because tocotrienols are found in the endosperm fractions, which are mostly removed during the fractionation of corn germ. Thus, despite having lower tocopherol concentration, all of the post-fermentation oils were higher in total tocol concentration compared to the CG oil.
[0060] The post-fermentation corn oils were much higher in carotenoids than the extracted corn germ oil as well. However, the concentration of carotenoids was substantially lower than the tocols in five oils (Table 5). As with tocotrienols, carotenoids are localized to the endosperm fraction of corn kernels. The main carotenoids in the oils were lutein and zeaxanthin, as well as lower quantities of beta-cryptoxanthin and beta-carotene. Carotenoid content and composition were similar to amounts found in DDGS oil in a previous study, however, Moreau et al. (2010) reported carotenoid content in centrifugally extracted thin stillage oil ranging from 295 to 405 µg / g oil. Carotenoids are substantially affected by corn hybrid, which may explain the discrepancy. Beta-carotene and beta-cryptoxanthin are both precursors to Vitamin A, while lutein and zeaxanthin are both protective against age-related macular degeneration and cataracts. Carotenoids have also been shown to have a number of beneficial physiological actions other than Vitamin A activity, including antioxidant activity, enhanced immune response, and chemoprotective activity against several types of cancer.Content and Composition of Phytosterols
[0061] The content of total phytosterols in the three oils ranged from 1.5-2.0% (w / w) (Table 6). The post-fermentation corn oils were higher in total phytosterols compared to the CG oil because they include phytosterols and ferulate phytosterol esters from the bran and pericarp, in addition to the phytosterols from the germ portion of the corn kernel. The phytosterol composition is also different between CG oil and the post-fermentation corn oils. DDGS and CS-1, CS-2, and CS-3 oils had similar concentrations of the common phytosterols campesterol, stigmasterol, and sitosterol compared to CG oil. However, they had a much higher concentration of the two saturated phytosterols (phytostanols), campestanol and sitostanol. The high content of these phytostanols is due to their preferential esterification, in corn, to steryl ferulates, the contents of which are also shown in Table 6. Steryl ferulates are found in the inner pericarp of corn and other grains. The presence of a small amount of these compounds in the corn germ oil indicates that there may have been some contamination of the germ by some inner pericarp tissue, as it has been established that these compounds are unique to the aleurone layer of the pericarp. Phytosterols are highly valued as ingredients in functional foods due to their ability to lower blood cholesterol by blocking readsorption of cholesterol from the gut. Steryl ferulates have been shown to retain the cholesterol lowering ability of phytosterols, and also have antioxidant activity due to the ferulic acid moiety. TABLE 6Content and compositions of phytosterols in oils extracted from corn germ (CG), distillers dried grains with solubles (DDGS), and centrifugally extracted thin stillage syrup (CS-1, CS-2, CS-3).CGDDGSCS-1CS-2CS-3mg / q% a< mg / g%mg / g%mg / g%mg / q%Total Phytosterols14.921.718.720.120.2Campesterol3.0820.72.9713.72.7414.72.7413.63.014.7Campestanol0.251.71.356.21.407.51.306.51.46.7Stigmasterol0.986.61.105.10.764.10.914.50.894.4Sitosterol9.0460.910.347.58.7746.99.3646.59.346.1Sitostanol0.664.43.7217.23.5919.23.4517.23.216.0Avenasterol0.543.70.934.30.864.60.944.71.05.2Cycloartenol0.281.90.713.20.593.20.743.70.733.624-methylene cycloartanolND b< 00.301.4ND00.341.70.301.5CitrostadienolND00.311.4ND00.311.60.361.8Steryl Ferulates (mg / g)0.583.93.4215.73.1516.83.3816.83.3516.6 a< The weight percentage of total phytosterols b< Not detected Oxidative Stability Index (OSI)
[0062] The oxidative stability of oils are affected by many factors, including fatty acid composition, concentration and stability of antioxidants in the oil, and the presence of prooxidant compounds, such as free fatty acids, lipid peroxides, or prooxidant metals. The Rancimat is an accelerated test (taking several hours to a day, depending on the oil and test temperature) used to establish the relative oxidative stability of oils, as measured by the induction time (called the oxidative stability index, OSI) for an oil to begin oxidizing under controlled temperature and air flow conditions. The OSI of the CG oil was lowest, while DDGS oil had the highest stability (Table 5), which corresponds to the lowest and the highest concentration of antioxidant tocopherols. CS-1 had a slightly lower OSI than CS-2 and CS-3 despite having a higher concentration of tocols; this may be explained by its higher content of FFA and higher initial peroxide value.Conclusions
[0063] This Example compared the composition and oxidative stability of oils extracted from corn germ, corn distillers dried grains, and from thin stillage from a conventional dry grind ethanol production facility as well as from a raw starch ethanol production facility. The fatty acid compositions of all five oils were typical for corn oil. Oil extracted from thin stillage in a raw starch production facility has lower FFA than from thin stillage from a conventional dry grind ethanol production facility. This is likely due to lower processing temperatures used in the raw starch process where the cooking stage is eliminated. All of the post-fermentation oils had higher concentrations of tocotrienols, carotenoids, phytosterols, and ferulate phytosterol esters compared to the corn germ oil. The increased concentrations of the antioxidant tocotrienols carotenoids, and steryl ferulates are likely responsible for their increased stability compared to corn germ oil.Other Exemplary Embodiments
[0064] Also provided is a corn oil composition comprising unrefined corn oil having an ethyl ester content that is greater than 7 weight percent, e.g., greater than 18 weight percent; and optionally a moisture content of from about 0.02 to about 1 weight percent and / or an alkali metal ion and / or alkaline metal ion content of greater than 10 ppm up to about 1000 ppm. In one embodiment, the unrefined corn oil has a free fatty acid content of less than about 5 weight percent. In one embodiment, the unrefined corn oil has an ethyl ester content that is greater than 30 weight percent. In one embodiment, the unrefined corn oil has an insoluble content of less than about 1.5 weight percent. In one embodiment, the unrefined corn oil has a free fatty acid content of less than about 3 or less than about 2 weight percent. In one embodiment, the unrefined corn oil has a peroxide value of less than about 2 parts per million. The corn oil composition may include a lutein content of at least 50 mcg / g, a zeaxanthin content of at least 30 mcg / g, a cis-lutein / zeaxanthin content of at least 10 mcg / g, an alpha-cryptoxanthin content of at least 5 mcg / g, a beta-cryptoxanthin content of at least 5 mcg / g, an alpha-carotene content of at least 0.5 mcg / g, a beta-carotene content of at least 1 mcg / g, a cis-beta-carotene content of at least 0.1 mcg / g, an alpha-tocopherol content of at least 50 mcg / g, a beta-tocopherol content of at least 2 mcg / g, a gamma-tocopherol content of at least 300 mcg / g, a delta-tocopherol content of at least 15 mcg / g, an alpha-tocotrienol content of at least 50 mcg / g, a beta-tocotrienol content of at least 5 mcg / g, a gamma-tocotrienol content of at least 80 mcg / g, a delta-tocotrienol content of at least 5 mcg / g, or any combination thereof.
[0065] In one embodiment, to prepare a vegetable oil composition, fermentation is employed. For example, a method for enhancing vegetable oil properties from ground plant material subjected to fermentation is provided. The method includes providing an aqueous composition comprising ground plant material, e.g., seeds, sized such that more than 50% of the ground material passes through a 0.5 mm screen, a fungal acid amylase and a glucoamylase under conditions which produce glucose including a pH of from 3 to 6, a temperature of from about 25°C to about 40°C and a solids content in said composition of from about 20 to 50 weight percent; and fermenting the glucose in the presence of a yeast and a composition comprising an esterase under conditions which produce ethanol and vegetable oil having an ethyl ester content that is greater than 18% w / w based on the total weight of the oil composition, wherein said conditions include a pH of from about 3 to 6 and maintaining a glucose concentration in the aqueous composition of less than about 2 weight percent after 12 hours of saccharification and fermentation, wherein said method produces at least 18 volume percent ethanol. In one embodiment, the vegetable oil has a free fatty acid content of no greater than 5% w / w based on the total weight of the composition. In one embodiment, the ethyl ester content is greater than about 20% w / w in the total weight of the oil composition. In one embodiment, the ethyl ester content is greater than about 30% w / w in the total weight of the composition. In one embodiment, the ethyl ester content is greater than about 50% w / w in the total weight of the oil composition. In one embodiment, the ethyl ester content is greater than about 60% w / w in the total weight of the oil composition. In one embodiment, the esterase is a plant or a fungal esterase. In one embodiment, the esterase is a carboxylic ester hydrolase (EC 3.1.1.3). In one embodiment, the esterase is a lipase. In one embodiment, the esterase is in an amount that is at least 0.01 % w / w of the weight of plant fat in the aqueous composition prior to fermentation. In one embodiment, the esterase is in an amount that is at least 0.04 % w / w of the weight of plant fat in the aqueous composition prior to fermentation. In one embodiment, the esterase is in an amount that is at least 0.4 % w / w of the weight of plant fat in the aqueous composition prior to fermentation. In one embodiment, during the production of ethanol, the pH is maintained at 3-4.5 during the first half of the fill cycle and at 4.5-6.0 during the second half of the fill cycle. In one embodiment, glucose is produced at a temperature of from about 30° C to about 35°C, a solids content in said composition of from about 25 to 45 weight percent, an amount of said fungal acid amylase which ranges from about 0.1 to about 10 fungal acid amylase units per gram of said dry solids, and an amount of said glucoamylase to dry solids in said composition which ranges from about 0.5 to about 6 glucoamylase units per gram of said dry solids. In one embodiment, the glucose is fermented under conditions comprising an initial temperature of about 35°C which temperature is decreased during fermentation to a temperature of about 30°C, and maintaining a glucose concentration in the aqueous composition of less than about 1 weight percent after 12 hours of saccharification and fermentation, wherein the production of glucose and the fermentation of glucose to ethanol is conducted simultaneously.
[0066] In one embodiment, to prepare a vegetable oil composition, fermentation is employed. For example, a method for enhancing vegetable oil properties from ground plant material subjected to fermentation is provided. The method includes providing an aqueous composition comprising ground plant material, e.g., seeds, sized such that more than 50% of the ground material passes through a 0.5 mm screen, a fungal acid amylase and a glucoamylase under conditions which produce glucose including a temperature of from about 25°C to about 40°C and a solids content in said composition of from about 20 to 50 weight percent; and fermenting the glucose in the presence of a yeast and a composition comprising an esterase under conditions which produce ethanol and vegetable oil having an ethyl ester content that is greater than 18% w / w based on the total weight of the oil composition. In one embodiment, the vegetable oil has a free fatty acid content of no greater than 5% w / w based on the total weight of the composition. In one embodiment, the ethyl ester content is greater than about 20% w / w in the total weight of the oil composition. In one embodiment, the ethyl ester content is greater than about 30% w / w in the total weight of the composition. In one embodiment, the ethyl ester content is greater than about 50% w / w in the total weight of the oil composition. In one embodiment, the ethyl ester content is greater than about 60% w / w in the total weight of the oil composition. In one embodiment, the esterase is a plant or a fungal esterase. In one embodiment, the esterase is a carboxylic ester hydrolase (EC 3.1.1.3). In one embodiment, the esterase is a lipase. In one embodiment, the esterase is added when fermentation is initiated, after fermentation is initiated, when fermentation is complete, or any combination thereof. In one embodiment, the esterase is in an amount that is at least 0.01 % w / w of the weight of plant fat in the aqueous composition prior to fermentation. In one embodiment, the esterase is in an amount that is at least 0.04 % w / w of the weight of plant fat in the aqueous composition prior to fermentation. In one embodiment, the esterase is in an amount that is at least 0.4 % w / w of the weight of plant fat in the aqueous composition prior to fermentation. In one embodiment, glucose is produced at a temperature of from about 30° C to about 35°C, a solids content in said composition of from about 25 to 45 weight percent, an amount of said fungal acid amylase which ranges from about 0.1 to about 10 fungal acid amylase units per gram of said dry solids, and an amount of said glucoamylase to dry solids in said composition which ranges from about 0.5 to about 6 glucoamylase units per gram of said dry solids. In one embodiment, the glucose is fermented under conditions comprising an initial temperature of about 35°C which temperature is decreased during fermentation to a temperature of about 30°C.
[0067] In one embodiment, a method for providing a corn oil composition with enhanced levels of, in one embodiment, ethyl ester, includes obtaining a first aqueous layer from a corn fermentation residue; adjusting the pH of the first aqueous layer to provide a corn oil layer and a second aqueous layer; and separating the corn oil layer from the second aqueous layer to provide the corn oil composition having a free fatty acid content of less than about 2% or less than about 5% and has at least 10% w / w ethyl ester. In one embodiment, the first aqueous layer has a moisture content of between about 95% and about 60%. In one embodiment, the first aqueous layer comprises thin stillage. In one embodiment, the method further comprises evaporating the thin stillage prior to the step of adjusting the pH of the first aqueous layer. In one embodiment, the first aqueous layer comprises syrup. In one embodiment, adjusting the pH comprises adding a base. In one embodiment, adjusting the pH comprises adding a base selected from the group consisting of sodium hydroxide, potassium hydroxide, calcium hydroxide, or spent alkali wash solution. In one embodiment, the pH of the first aqueous layer is less than about 4 prior to the step of adjusting the pH of the first aqueous layer. In one embodiment, the pH of the first aqueous layer is about 3.5 prior to the step of adjusting the pH of the first aqueous layer. In one embodiment, the pH of the first aqueous layer is from about 7.5 to about 10 after adjusting the pH of the first aqueous layer. In one embodiment, the pH of the first aqueous layer is from about 8 to about 9 after adjusting the pH of the first aqueous layer. In one embodiment, the pH of the first aqueous layer is about 8.2 after adjusting the pH of the first aqueous layer. In one embodiment, obtaining the first aqueous layer from the corn fermentation residue comprises centrifuging. In one embodiment, obtaining the first aqueous layer from the corn fermentation residue comprises a) separating the first aqueous layer into a water layer and an emulsion layer; and b) adjusting the pH of the emulsion layer to provide a corn oil layer and a second aqueous layer. In one embodiment, obtaining the first aqueous layer from the corn fermentation residue to provide an emulsion layer and a first aqueous layer comprises centrifuging. In one embodiment, separating the corn oil layer from the second aqueous layer comprises centrifuging. In one embodiment, the corn oil layer comprises a free fatty acid content of less than about 2 weight percent. In one embodiment, the corn oil layer comprises a moisture content of from about 0.2 to about 1 weight percent. In one embodiment, the corn oil layer comprises an alkali metal ion and / or alkaline metal ion content of greater than 10 parts per million. In one embodiment, the corn oil layer has an insoluble content of less than about 1.5 weight percent. In one embodiment, the corn oil layer exhibits a peroxide value of less than about 2 parts per million. In one embodiment, the corn oil layer exhibits an oxidative stability of greater than about 4 hours at a temperature of about 110°C.
[0068] Also provided is a method for making a paving composition. The method includes combining a plurality of solids (aggregate) with an asphalt binder blend composition to produce a paving composition, wherein the asphalt binder blend composition comprises bitumen and a corn oil composition having: an ethyl ester content of greater than 7%, e.g., greater than about 18%, w / w based on the total weight of the oil composition; and optionally an iodine value of not greater than 125 and / or a combined moisture and insoluble content of no greater than 1.5% w / w based on the total weight of the composition; and also optionally a further component selected from the group consisting of: a lutein content of at least 50 mcg / g, a cis-lutein / zeaxanthin content of at least 10 mcg / g, an alpha-cryptoxanthin content of at least 5 mcg / g, a beta-cryptoxanthin content of at least 5 mcg / g, an alpha-carotene content of at least 0.5 mcg / g, and a cis-beta-carotene content of at least 0.1 mcg / g. In one embodiment, the plurality of solids comprises sand, gravel, crushed stone, crushed concrete, crushed glass, industrial slag, or any mixture thereof.
[0069] In addition, an asphalt mix composition is provided comprising: recycled asphalt and a vegetable oil composition having an ethyl ester content that is greater than about 7% such as greater than about 18% w / w based on the total weight of the oil composition; and optionally an iodine value of not greater than 125 and / or a combined moisture and insoluble content of no greater than 1.5% w / w based on the total weight of the composition; and also optionally a further component selected from the group consisting of: a lutein content of at least 50 mcg / g, a cis-lutein / zeaxanthin content of at least 10 mcg / g, an alpha-cryptoxanthin content of at least 5 mcg / g, a beta-cryptoxanthin content of at least 5 mcg / g, an alpha-carotene content of at least 0.5 mcg / g, and a cis-beta-carotene content of at least 0.1 mcg / g. In one embodiment, the vegetable oil is about 1 wt % to about 25 wt % based on weight of the asphalt binder composition or the asphalt binder blend composition. In one embodiment, the vegetable oil is about 0.5 wt % to about 25 wt % based on weight of the asphalt binder composition or the asphalt binder blend composition. In one embodiment, the asphalt mix composition comprises virgin asphalt and recycled asphalt.
[0070] The invention will be further described with respect to the following examples.Example 1 Materials and Methods
[0071] A simultaneous saccharification and fermentation (SSF) process is employed, where starch-based feedstocks such as corn (maize), sorghum (milo), and / or wheat, are used for the production of ethanol. In this process, raw starch hydrolyzing enzymes are used to breakdown the starch into monomeric glucose which is then metabolized by the microorganism (yeast, Saccharomyces cerevisiae) to produce ethanol. This process may also be termed as raw starch hydrolysis or cold cook process.Compositional Analysis of Raw Materials
[0072] Corn is first processed with a Hammer mill using 0.5 mm to 2.0 mm screens to grind the flour to the required particle size. The percent solids and percent moisture of the corn flour and preblend used in fermentation is determined by mass loss on drying in a 100°C oven. Preblend is defined as a nutrient source derived from recycled plant makeup water composed of diluted and partially clarified thin stillage. The fat content of the flour is determined by accelerated fat extraction utilizing an extraction system (Dionex ASE 350) with hexane as the extracting solvent.Yeast propagation and conditioning
[0073] First, 1-3 colonies of yeast isolated off a yeast extract and soy peptone containing 3% glucose (YP medium) agar plate, or alternatively slurried dry yeast or crème yeast, were used to inoculate 50 mL of YP culture media in a shake flask. This was then allowed to shake in a water bath at 150 rpm overnight for approximately 17 hours at 30°C. The conditioning medium was then prepared in a 1 L Pyrex bottle capped with a lid with a hole to release carbon dioxide produced during fermentation. To the fermenter bottle, corn flour was added and slurried up to a final solids loading of 32% using preblend. The slurry was pH adjusted to 4.5 using 10% (% v / v) sulfuric acid. In addition, an appropriate amount of antibiotic, urea, a cocktail of α-amylases and glucoamylases are added to the slurry according to U.S. Patent No. 7,842,484. Yeast culture at approximately 1.0E+07 cells mL -1< was added to the fermenter to give a final number of 7.0E+08 yeast cells in the fermenter. The conditioning fermentation was allowed to ferment in a water batch shaking at 150 rpm at 30 - 32.2 °C for eight hours.Fermentation
[0074] Fermentation was carried out as in the conditioning step according to U.S. Patent No. 7,842,484 unless stated otherwise. For fermentation, a 500 mL Pyrex bottles were used for a total fermentation volume of 250 mL. The corn was slurried with preblend to a total percent solids of 36.5%. In addition, an esterase such as a lipase (Novozymes Eversa Transform 2.0), was added to the slurry as well. The dose of the enzyme is based upon the total weight of corn fat present in the fermenters. A typical dose is 0.4% (% w / w), although experiments with 0.04% and 4.0% were performed as well. Fermentation in the bottles was allowed to progress for 88 hours, at which point the beer was sampled and harvested for oil analysis.Oil Extraction and AnalysisOil Extraction
[0075] The oil was extracted from the entire volume of beer remaining after sampling. First, the beer was centrifuged at approximately 4°C for 20 minutes at 4500 rpm in a bench centrifuge. The resulting floating oil emulsion was then removed. The emulsion was put in 50 mL conical tubes to which approximately 10-20 mL of chloroform was added and vortexed. Then 10-20 mL of deionized water was also added to help with separation. The 50 mL tubes were then centrifuged at 3000 rpm for five minutes. The bottom layer (chloroform + oil) was pulled off and put into tared glass vials and inserted into a turbovap to evaporate off the solvent. The resulting dry oil was then used to quantify fatty acid ethyl esters.Fatty Acid Ethyl Ester Determination by Gas Chromatography
[0076] Approximately 50 mg of the extracted oil was added to a 10 mL volumetric flasks to which xylene was added to the 10 mL graduation. External standards including ethyl palmitoleate, ethyl oleate, and ethyl linoleate were used to generate standard curves to determine the amount of each individual fatty acid ethyl ester present in the extracted corn oil. Standard concentrations used ranged from 0.02 mg mL -1< to 0.40 mg mL -1< . The samples and standards were run on a gas chromatograph (GC) equipped with a split / splitless injector (with splitless glass liner) and flame ionization detector (FID). Also, the GC was equipped with a Phenomenex Zebron ZB-Waxplus column (30m Lx 0.32 mm ID x 0.25 µm df). Analysis was conducted by injecting 1 µL of the sample into the inlet held at 250°C. The oven was initially set at 170°C and followed an oven temperature gradient of 2°C min -1< up to 200°C holding for 15 minutes, followed by a temperature gradient of 5°C min -1< up to 230°C holding for nine minutes. The detector was maintained at a temperature of 250°C. Hydrogen was used as the carrier gas and the flow was controlled in constant flow mode at 1.80 mL min -1< .
[0077] Major ethyl esters in corn oil are ethyl palmitate, ethyl stearate, ethyl oleate, ethyl linoleate, and ethyl linolenate. In one embodiment, the ethyl esters include about 5% w / w to about 22% w / w ethyl palmitate, about 1% w / w to about 5% w / w ethyl stearate, about 23% w / w to about 30% w / w ethyl oleate, about 53% w / w to about 60% w / w ethyl linoleate, and about 1% w / w to about 2% w / w ethyl linolenate of FAEE. In one embodiment, the ethyl palmitate is about 23% w / w to about 35% w / w, ethyl stearate is about 1% w / w to about 5% w / w, ethyl oleate is about 10% w / w to about 22% w / w, ethyl linoleate is about 40% w / w to about 52% w / w, and ethyl linolenate is about 2% w / w to about 3% w / w of FAEE. In one embodiment, the ethyl palmitate is about 23% w / w to about 35% w / w, ethyl stearate is about 1% w / w to about 5% w / w, ethyl oleate is about 10% w / w to about 22% w / w, ethyl linoleate is about 40% w / w to about 61% w / w, and ethyl linolenate is about 2% w / w to about 3% w / w of FAEE. With the aforementioned instrument parameters, ethyl palmitate would elute around 11 minutes, ethyl stearate around 16.5 minutes, ethyl oleate around 17 minutes, ethyl linoleate around 18 minutes, and ethyl linolenate around 19.5 minutes. A standard curve of each ethyl ester is obtained to give the slope and y-intercept for quantitation. Ethyl palmitate concentration is determined by the ethyl palmitoleate standard curve, ethyl stearate and ethyl oleate concentration are determined by the ethyl oleate standard curve, and ethyl linoleate and ethyl linolenate concentrations are determined from the ethyl linoleate standard curve. The total FAEE content of each sample is determined using the equation below. % FAEE % mg / mg = ∑ A x − y int ⋅ 10 S ⋅ m Where: A x =Area corresponding to the peaks for the individual esters Y int =y-intercept of the linear regression S =Slope of the linear regression m =Mass of the sample, in milligrams Example 2
[0078] Corn oil extracted from ethanol fermentation is mostly in the form of triacylglyceride and is typically sold into limited markets (animal feed, food grade or bio-diesel) due to lack of industrial utility. In order to increase the utility of the corn oil, an esterase can be added directly to fermentation to facilitate chemical modification of the corn oil to give it unique properties, specifically by increasing the ethyl ester content. Increased ethyl ester content lends to lower viscosity which is desirable in asphalt rejuvenation and performance grade composition. The transesterification / esterification of corn triacylglycerides / free fatty acids with ethanol produced during fermentation can have several added benefits such as increased oil yield, increase yeast vitality due to liberation of free fatty acids and glycerol, as well as enhanced starch utilization.
[0079] Avoiding a high temperature liquefaction step of corn prior to fermentation has several benefits. One such potential benefit is that the corn oil extracted post fermentation has a higher concentration of long chain ethyl esters. The high temperature liquefaction likely destroys endogenous corn enzymes which contribute to the formation of fatty acid ethyl esters (FAEE) (Figure 6). With this knowledge, addition of exogenous esterase, e.g., a lipase, was added to the fermentation to demonstrate that ethyl ester content of extracted oil can be increased even further, e.g., greater than 60% (% w / w). Figure 7 shows that the FAEE content of the extracted corn oil can be increased beyond 80% w / w.
[0080] Thus, in order to increase the utility of the corn oil, an esterase such as a lipase can be added directly to the fermentation to facilitate chemical modification of the corn oil to give it unique properties, specifically by increasing the ethyl ester or FAEE content, respectively. The transesterification / esterification of corn triacylglycerides / free fatty acids with ethanol produced during fermentation can have several added benefits such as increase oil yield, increased yeast vitality due to liberation of free fatty acids and glycerol, as well as enhanced starch utilization.Example 3
[0081] Recycled asphalt in pavement and shingles is often very stiff and viscous which can cause premature cracking due to lack of durability as well as loss of workability in its use. In order to rejuvenate recycled asphalt by reducing the viscosity, softening, and increasing the durability of asphalt mixtures, vegetable oils such as corn oil that are enhanced with fatty acid ethyl esters (see Example 2) can be mixed with asphalt binder or asphalt mixes containing recycled asphalt. High ethyl ester containing corn oil is shown herein to rejuvenate recycled asphalt in the aforementioned ways better than corn oil with a low ethyl ester content.
[0082] Recycled asphalt increases the stiffness and makes asphalt blends prone to low temperature cracking (Mogawar et al., 2013). The use of rejuvenators such as waste vegetable oils, waste grease, re-refined engine oil bottoms, crude tall oils, and aromatic oils have shown promise to reduce stiffness and improve low temperature cracking characteristics (Zaumanis et al., 2014). Although corn oil is known to inherently have low viscosity properties due to the presence of unsaturated fatty acids, as described herein, the inclusion of ethyl esters or fatty acid ethyl esters reduces the viscosity even further and increases its effectiveness as a rejuvenator.
[0083] An increase in the relative durability of the asphalt is determined by calculating the increase in ΔT c of aged asphalt after rejuvenation with such a material. The ΔT c is the difference between the continuous stiffness temperature and the continuous relaxation temperature measured by the bending beam rheometer test (AASHTO T313). Asphalt binder with lower or more negative ΔT c values extracted from recycled asphalt pavement have been shown to experience premature cracking (Bennert et al., 2016).
[0084] Figure 8 demonstrates that corn oil containing higher concentrations of ethyl esters leads to a lowering of the corn oil viscosity. Figure 9 shows that blending aged asphalt with higher inclusion of ethyl esters in corn oil leads to a desirable increase in the aged asphalt ΔT c value. Higher concentrations of ethyl esters reduce the relaxation temperature of aged asphalt binder, and hence improve the low temperature properties.Example 4
[0085] Recycled asphalt in pavement (RAP) is often very stiff and viscous which can cause premature cracking due to lack of durability as well as loss of workability in its use. Distiller's corn oil (DCO), e.g., produced with added esterase in the fermentation, can be utilized to reduce the viscosity, improve the low temperature properties, as well as increase the durability of the recycled asphalt for use in asphalt mixes. DCO may be used with asphalt mixes containing 1% to 50% RAP in order to increase the cracking resistance while not exceeding the rutting limit. Additionally, DCO can be used to modify the grade of various performance grade (PG) asphalts in order to improve the low temperature properties. The composition of the aforementioned DCO contains greater than 18% fatty acid ethyl ester (FAEE) by weight.
[0086] Waste vegetable oils, waste grease, re-refined engine oil bottoms, crude tall oils, and aromatic oils can be used to modify the PG of asphalt, reducing the stiffness and improving the low temperature properties making their use more amenable to particular climates (Golalipour, 2013).
[0087] Recycled asphalt and some PG asphalts are very viscous and stiff which would benefit from a rejuvenating or softening agent. DCO can lower the stiffness of the aforementioned asphalt and can improve the low temperature properties by making it less susceptible to cracking. In addition, DCO can be added to asphalt mixes containing 1%-50% RAP in order to soften the asphalt, increase the durability of the asphalt, and improve cracking resistance while not exceeding the rutting specification.
[0088] Figure 10 shows the PG modification of a 64-22 asphalt to a 58-28 and 52-34 with 4 and 7 percent inclusion of DCO, respectively. DCO can also be used in asphalt rejuvenation applications. Figure 11 demonstrates the use of DCO can increase the ΔT c value of aged asphalt, which is a measure of the durability of the asphalt. Thus, the inclusion of 4% DCO in a 50% RAP mixture can significantly increase the cracking resistance as well as pass the specification for rutting, respectively.
[0089] DCO can also be used in asphalt rejuvenation of recycled asphalt present in RAP and RAS. As asphalt is aged, the binder becomes oxidized and hardens decreasing the ΔT c value indicating a loss of durability. In order to rejuvenate aged asphalt, DCO can be added to the recycled asphalt in order to increase the ΔT c value. In addition, inclusion of DCO increases the mix performance of RAP blends as observed as an increase in both low and intermediate cracking resistance without causing the mix to become susceptible to rutting. Typical inclusion of RAP in asphalt mixes may range from 1% to 50%. Inclusion of DCO in RAP containing asphalt mixtures may range from 0.5% to 50%, e.g., 25%, based upon the weight of the binder that includes the recycled asphalt or total weight of the asphalt. For a hot mix, RAP or RAS can be rejuvenated by several different methods. DCO can be added onto the RAP or RAS stockpiles, added directly into the mix drum, or injected into the virgin asphalt. RAP / RAS can be pretreated by spraying the stream prior to its addition to the mix drum. DCO can also be added to virgin asphalt in storage tanks equipped with mixers or it can be added with an in-line static mixer downstream prior to reaching the mix drum.
[0090] Typical mix design of asphalt formulations with and without inclusion of RAP and an exemplary corn oil composition, DCO, are shown in Table 7. Table 7. Typical Asphalt Mix Design for Virgin, 50% RAP, and 50% RAP with Inclusion of Corn Oil Compositions ("DCO")Volumetrics Virgin 50% RAP 50% RAP + DCO a< Requirement Total Binder, %6.16.06.0---Virgin Binder (PG 67-22), %6.13.163.16--Binder from RAP, %02.842.84--Air Voids, %4.04.04.04.0VMA b< , %16.816.716.5> 15.0VFA c< , %75767673-76Ratio of Dust to Asphalt1.21.21.20.6 - 1.2 a< DCO is included at 4% based upon the total weight of the binder blend (or 8% based upon the recycled asphalt binder (in the 50% mix) b< VMA: Voids in the Mineral Aggregate c< VFA: Voids Filled with Asphalt References
[0091] Bennert et al., Transp. Res. Rec. J. Transp. Res. Board, 2514:1 (2016). Cox, Asphalt Binders Containing a Glyceride and Fatty Acid Mixture and Methods for Making and Using Same. (2016). DiCosimo et al., In situ expression of lipase for enzymatic production of alcohol esters during fermentation (2014). Golalipour, Investigation of the Effect of Oil Modification on Critical Characteristics of Asphalt Binders. PhD Thesis (2013). Grichko, Fermentation processes and compositions (2004). Hughes et al., J. Assoc. Lab. Autom., 16:17 (2011). Lackey & James, Biodiesel cutback asphalt and asphalt emulsion. (2004). Mogawer et al., Road Mater. Pavement Des., 14:193 (2013). Moreau et al., J. Am. Oil Chem. Soc., 88:435 (2010) Seidel & Haddock, Constr. Build. Mater., 53:324 (2014). van den Berg et al., Biotechol. Bioenq., 110:137 (2013). Zaumanis et al., Constr. Build. Mater., 71:538 (2014). Winkler et al., J. Agric. Food Chem., 55:6482 (2007). Winkler-Moser and Vaughn, J. Am. Oil Chem. Soc., 86:1073 (2009).
Claims
1. Use of a corn oil composition comprising corn oil having a fatty acid ethyl ester content that is greater than 7% w / w based on the total weight of the oil composition in an asphalt binder blend composition comprising the corn oil, recycled asphalt and optionally virgin asphalt or in an asphalt mix composition comprising the corn oil and virgin asphalt, the corn oil being for use in an amount that is effective to alter one or more properties of the asphalt binder blend composition or asphalt mix composition relative to a corresponding composition that lacks the corn oil composition, wherein the one or more properties include viscosity, ΔTc value, rutting or thermal cracking; and wherein the corn oil is for use in an asphalt binder blend composition in which the corn oil is 0.5 wt% to 25 wt% of the asphalt or wherein the corn oil is for use in an asphalt mix composition in which the corn oil is 0.5 wt % to 25 wt % of the weight of the asphalt (bitumen without aggregates).
2. The use of claim 1, wherein the ΔTc is increased as a result of the presence of the corn oil.
3. The use of any preceding claim, wherein the fatty acid ethyl ester content is greater than about 20% w / w in the total weight of the oil composition.
4. The use of any preceding claim, wherein the corn oil composition has an iodine value of not greater than 125 and / or a combined moisture and insoluble content of no greater than 1.5% w / w based on the total weight of the composition.
5. The use of any preceding claim, wherein the corn oil has a further component selected from the group consisting of: a lutein content of at least 50 mcg / g; a cis-lutein / zeaxanthin content of at least 10 mcg / g; an alpha-cryptoxanthin content of at least 5 mcg / g; a beta-cryptoxanthin content of at least 5 mcg / g; an alpha-carotene content of at least 0.5 mcg / g; and a cis-beta-carotene content of at least 0.1 mcg / g.
6. The use of any preceding claim, wherein the free fatty acid content of the corn oil comprises at least one fatty acid selected from the group consisting of C16 palmitic, C18 stearic, C18-1 oleic, C18-2 linoleic, and C18-3 linolenic.
7. The use of any preceding claim, wherein the oil composition further comprises an unsaponifiables content of no greater than 3% w / w based on the total weight of the composition.
8. The use of any preceding claim, wherein the corn oil is for use in the asphalt blend composition and in which the corn oil is 5 wt % to 10 wt % of the weight of the asphalt binder composition.