# Patent

## Title
Process for preparing Tier 3 reference fuel

## Abstract

A process for preparing an E10 test fuel in accordance with 40 CFR 1065.710(b) includes steps of combining an aromatic pre-blend having an aromatic distribution in accordance with 40 CFR 1065.710(b), or a combination of aromatic blendstocks that if combined into a mixture would have an aromatic distribution in accordance with 40 CFR 1065.710(b), with at least one paraffinic refining blendstock, and optionally adding ethanol, butane, olefin-containing blendstocks, sulfur compounds or sulfur-containing blendstocks as needed to meet the requirements of 40 CFR 1065.710(b).

## Background
CROSS-REFERENCE TO RELATED APPLICATIONS
Not Applicable.
FIELD OF THE DISCLOSURE
This disclosure relates to reference fuels used as a standard for emissions testing of light and heavy duty vehicles, and more particularly to the preparation of Tier 3 reference fuels.
BACKGROUND OF THE DISCLOSURE
In an effort to further reduce motor vehicle emissions and improve air quality and public health, the United States Environmental Protection Agency has promulgated new rules that require lowering of sulfur content in gasoline beginning in 2017, and reduction of evaporative emissions from passenger cars, light-duty trucks, medium-duty passenger vehicles, and some heavy-duty vehicles (40 CFR parts 79, 80, 85 et al., titled “Control of Air Pollution from Motor Vehicles: Tier 3 Motor Vehicle Emission and Fuel Standards; Final Rule). Under the Tier 3 program, gasoline shall not contain more than 10 parts per million sulfur on an annual average basis by Jan. 1, 2017. This reduction is expected to reduce catalyst fouling and substantially improve the effectiveness of the vehicle emission control systems, leading to significant reductions in emissions of nitrogen oxides, volatile organic compounds, carbon monoxide, particulate matter, benzene, sulfur dioxide, 1,3-butadiene, formaldehyde, acetaldehyde, acrolein, and ethanol.
Under the Tier 3 standards, new specifications for the gasoline emissions test fuel used for testing highway vehicles have been adopted to better match the fuel that is currently being used. Specifically, in-use gasoline has changed considerably since the EPA last revised specifications for gasoline. Sulfur and benzene levels have been reduced, and gasoline containing 10 percent ethanol by volume has replaced non-oxygenated gasoline across the country. Section 1065.710(b) of Title 40 of the Code of Federal Regulations specifies test fuel properties for gasoline with ethanol (low-level blend only). The specification requires an Antiknock Index (R+M)/2 of 87.0-88.4, a sensitivity (R−M) of 7.5 (minimum), a Dry Vapor Pressure Equivalent (DVPE) in units of kPa of 60.0-63.4, 10% evaporation during distillation at 49-60° C., 50% evaporation during distillation at 88-99° C., 90% evaporation during distillation at 157-168° C., a final boiling point of 193-216° C., a post-distillation residue of 2.0 milliliters (maximum) of a 100 milliliter specimen (see ASTM D86), total aromatic hydrocarbons content of 21.0-25.0 volume present, C6 aromatics (benzene) content of 0.5-0.7 volume percent, C7 aromatics (toluene) content of 5.2-6.4 volume percent, C8 aromatics content of 5.2-6.4 volume percent, C9 aromatics content of 5.2-6.4 volume percent, C10 plus aromatics content of 4.4-5.6 volume percent, a total olefins content of 4.0-10.0 mass percent, an ethanol content of 9.6-10.0 volume percent (blended) or 9.4-10.2 volume percent (confirmatory), a total content of oxygenates other than ethanol of 0.1 volume percent (maximum), a sulfur content of 8.0-11.0 mg/kg, a lead content of 0.0026 g/liter (maximum), a phosphorus content of 0.0013 g/liter (maximum), copper corrosion of No. 1 Maximum per ASTM D130, a solvent-washed gum content of 3.0 mg/100 milliliters (maximum), and an oxidation stability of 1000 minutes (minimum) per ASTM D525. The ethanol (blended) specification is based on the volume percent ethanol content as determined during blending by the fuel supplier and as stated by the supplier at the time of fuel delivery (see 40 CFR 1065.710(b)(3)). The ethanol (confirmatory) specification refers to the volume percent ethanol content as determined analytically.
Section 1065.710 of Title 40 also specifies that the low-level ethanol-gasoline test fuel blend having nominally 10% ethanol (commonly called “E10 test fuel”) must be prepared from typical refinery gasoline blending component, and “may not use pure compounds, except as follows: (i) you may use neat ethanol as a blendstock, (ii) you may adjust the test fuel's vapor pressure by adding butane, (iii) you may adjust the test fuel's benzene content by adding benzene, and (iv) you may adjust the test fuel's sulfur content by adding sulfur compounds that are representative of those found with in-use fuels.”
It has been determined that it is extremely difficult to meet all of the antiknock, sensitivity, distillation, and compositional requirements of 40 USC §1065.710(b) using typical refinery gasoline blending components in combination with neat ethanol, butane, benzene and representative sulfur compounds. Generally, substantial trial and error is required to achieve all specifications concurrently. Further, once an appropriate blend has been determined, it is only usable for a relatively short period of time, since typical refinery gasoline blending components are constantly changing due to factors such as the source of the crude oil and seasonal adjustments to refinery operating parameters. It is most difficult to formulate an E10 test fuel within the specification having the required ranges for the various aromatic species while also meeting the total aromatic content and fuel distillation profile. Typical refinery gasoline blending components (or blendstocks) having a high aromatic content include heavy straight run (HSR) naphtha (petroleum), Aromatic 100 (a composition generally comprising a minimum of 98.0 volume percent aromatics and having a flashpoint of about 100 degrees Fahrenheit), Aromatic 150 (a composition generally comprising a minimum of 98.0 volume percent aromatics and having a flashpoint of about 150 degrees Fahrenheit), and Aromatic 200 (a composition generally comprising a minimum of 98.0 volume percent aromatics and having a flashpoint of about 200 degrees Fahrenheit). A problem with these aromatic refinery streams is that the composition can vary widely from batch to batch. Specifically, the distribution of C7, C8, C9 and C10+ aromatics can vary considerably from batch to batch, making it very difficult to formulate a finished test fuel meeting the very tight specifications of 40 CFR 1065.710(b). It is particularly difficult to formulate an E10 test fuel in accordance with 40 CFR 1065.710(b) that complies with the various aromatic species ranges while also meeting the total aromatic content requirement and fuel distillation profile.
It is highly desirable to develop a process for preparing E10 test fuels in accordance with 40 CFR 1065.710(b) without employing a trial and error process typically requiring several iterative failures before meeting all specifications.
SUMMARY OF THE DISCLOSURE
A process for preparing E10 test fuel in accordance with 40 CFR 1065.710(6) is described. The process includes steps of: (I) providing an aromatic pre-blend prepared by mixing an aromatic refinery blendstocks to obtain a mixture comprising aromatic compounds in proportions as specified in 40 CFR 1065.710(b); (2) combining the aromatic pre-blend with ethanol and at least one paraffinic refinery blendstock to obtain a composition complying with most of the compositional, fuel quality, and distillation profile requirements of 40 CFR 1065.710(b); and (3) optionally adding butane as needed to adjust vapor pressure in accordance with 40 CFR 1065.710(b), optionally adding sulfur containing blendstock(s) or sulfur compounds as needed to comply with 40 CFR 1065.710(b), and optionally adding olefin containing blendstock(s) as needed to comply with 40 CFR 1065.710(b).
Alternatively, a process for preparing E10 test fuel in accordance with 40 CFR 1065.710(b) may comprise mixing (blending) aromatic refinery blendstocks with at least one paraffinic refinery blendstock, wherein the aromatic refinery blendstocks are selected such that if blended together without the at least one paraffinic refinery blendstock the resulting aromatic refinery blendstock mixture would comprise aromatic compounds in proportions as specified in 40 CFR 1065.710(b). Such alternative process may further comprise optionally adding butane as needed to adjust vapor pressure in accordance with 40 CFR 1065.710(b), optionally adding sulfur-containing blendstocks or sulfur compounds as needed to comply with 40 CFR 1065.710(b), and optionally adding olefin-containing blendstock(s) as needed to comply with 40 CFR 1065.710(b).
Also described is an aromatic pre-blend useful for preparing an E10 test fuel in accordance with 40 CFR 1065.710(b) by mixing it with a paraffinic refinery blendstock and optionally sulfur compound(s) and/or sulfur-containing blendstock(s), olefin-containing blendstock(s) and/or butane.
Other features and advantages of the present disclosure will become readily appreciated as the same becomes better understood after reading the following description.


DETAILED DESCRIPTION
It has been discovered that it is possible to substantially reduce, and typically eliminate, trial and error during preparation of E10 test fuel in accordance with 40 CFR 1065.710(b) by first preparing an aromatic pre-blend having the required proportions of C6, C7, C8, C9 and C10+ aromatics, then combining the aromatic pre-blend with ethanol and a paraffinic refinery blendstock (refinery process stream) having a low aromatic content in proportions that are expected to provide the required ethanol and total aromatic content and distribution of 40 CFR 1065.710(b), and which is expected to provide the required distillation profile, antiknock index, sensitivity, lead content, phosphorus content, copper corrosion characteristic, solvent-washed gum content, and oxidation stability. Thereafter, small amounts of butane can be added as needed to adjust the fuel vapor pressure, small amounts of sulfur-containing blendstock(s) representative of those found with in-use fuels can be added to raise the sulfur content to that required by 40 CFR 1065.710(b), and a small amount of olefin-containing blendstock(s) can be added to adjust the olefin content within the range required by 40 CFR 1065.710(b).
By properly adjusting the proportions of C6, C7, C8, C9 and C10+ aromatics in the pre-blend and combining the pre-blend with other blendstocks that do not have sufficiently high aromatic content to cause the C6-C10+ proportions in the combination to deviate substantially from that of the pre-blend, it is possible to meet all specification requirements without trial and error, or at least significantly reduce trial and error. In order to reduce or eliminate trial and error, it is desirable that the aromatic pre-blend is comprised of a very high proportion of aromatic compounds, such as at least 90 volume percent, at least 95 volume percent, or at least 98 volume percent. It is also desirable that the C6-C10+ proportions are as recited in 40 CFR 1065.710(b) (as published Apr. 28, 2014 at 79 FR 23809). Specifically, it is desirable that the C7:C6, C8:C6 and C9:C6 aromatic proportions are each in the range 5.2-6.4:0.5-0.7 (in units of volume), and that the C10+:C6 aromatic proportion is in the range 4.4-5.6:0.5-0.7 (in units of volume).
The paraffinic refinery blendstock (or blendstocks) should be selected such that when it is combined with ethanol and the aromatic pre-blend to provide a 10% ethanol gasoline (E10 test fuel), the resulting mixture has the distillation profile and other fuel characteristics specified in 40 CFR 1065.710(b). The paraffinic blendstock or combination of paraffinic blendstocks should have a low aromatics content such that the distribution of aromatics in the blendstock(s) does not cause the C6-C10+ proportions in the test fuel to vary significantly from the proportions in the pre-blend. It is recommended that the aromatic content of the refinery blendstock or combination of refinery blendstocks that are mixed with the aromatic pre-blend and the ethanol does not exceed 10 volume percent, 5 volume percent, or 2 volume percent. The ethanol can be pure, or substantially pure, e.g., at least 90 volume percent ethanol, at least 95 volume percent ethanol, or at least 96 volume percent ethanol.
Suitable aromatic refinery blendstocks that can be used for preparing the aromatic pre-blend include Aromatic-100, Aromatic-150, Aromatic-200, benzene, toluene, xylene (e.g., a mixture of o-, p- and m-xylene), 1,2,4-trimethyl benzene, 1,3,5-trimethyl benzene, diethylbenzene, and tetralin. Other blendstocks comprised primarily of aromatic species are also suitable and may be employed in the preparation of the aromatic pre-blend.
The C6-C10+ aromatic distributions and distillation profile for typical Aromatic-100 blendstocks is given in Table 1.











TABLE 1








RESULTS
RESULTS


TEST
METHOD
UNITS
SAMPLE A
SAMPLE B



















Distillation - IBP
ASTM D86
° F.
316
325


5%

° F.
321
326


10%

° F.
322
326


20%

° F.
324
326


30%

° F.
326
327


40%

° F.
327
327


50%

° F.
328
327


60%

° F.
329
328


70%

° F.
332
328


80%

° F.
336
329


90%

° F.
339
330


95%

° F.
340
333


Distillation - EP

° F.
351
345


Recovery

vol %
98.3
98.5


Residue

vol %
1.1
1.0


Loss

vol %
0.7
0.5


Gravity
ASTM D4052
API
30.5
30.5


Density @ 60° F.
ASTM D4052
kg/m3
872.5
872.5


Sulfur
ASTM D5453
wt %
<1
<1


Aromatics. Total
ASTM D6733
vol %
98.3
99.0


C8 Aromatics
ASTM D6733
vol %
5.5
0.2


C9 Aromatics
ASTM D6733
vol %
76.6
92.1


C10 Aromatics
ASTM D6733
vol %
15.5
5.9


Peroxide Content
ASTM D3703
ppm
<1
<1









The compositional analysis of a typical Aromatic-150 blendstock is given in Table 2.







TABLE 2





ASTM D-6733


















Component Name
WT %
LV %
Mol %





n-Propylbenzene
0.02
0.02
0.02


1-Methyl-3-ethyJbenzene 
0.08
0.08
0.09


(METOL)





1-Methyl-4-ethylbenzene (PETOL)
0.05
0.05
0.06


1,3,5-Trimethylbenzene
0.07
0.07
0.08


1-Methyl-2-ethylbenzene (OETOL)
0.07
0.07
0.08


1,2,4-Trimethylbenzene
1.05
1.04
1.21


Isobutylbenzene
0.10
0.10
0.10


sec-Butylbenzene
0.12
0.12
0.12


1,2,3-Trimethylbenzene
2.29
2.23
2.63


1-Methyl-3-isopropylbenzene
0.30
0.30
0.31


1-Methyl-4-isopropylbenzene
1.24
1.26
1.27


1-Methyl-2-isopropylbenzene
1.72
1.71
1.77


1-Methyl-3-n-propylbenzene
4.58
4.64
4.71


1-Methyl-4-n-propylbenzene
4.64
4.71
4.77


1,3-Dimethyl-5-ethylbenzene
5.28
5.30
5.43


1,2-Diethylbenzene
0.45
0.45
0.46


1-Methyl-2-n-propylbenzene
1.99
1.99
2.05


1,4-Dimethyl-2-ethylbenzene
4.13
4.10
4.24


1,3-Dimethyl-4-ethylbenzene
5.06
5.03
5.20


1,2-Dimethyl-4-ethylbenzene
9.58
9.55
9.85


1,3-Dimethyl-2-ethylbenzene
0.60
0.59
0.62


1,2-Dimethyl-3-Ethylbenzene
2.67
2.61
2.74


1-ethyl-4-isopropylbenzene
0.21
0.21
0.20


1,2,4,5-Tetramethylbenzene
6.37
6.28
6.55


1,2,3,5-Tetramethylbenzene
9.75
9.55
10.02


1,2,3,4-Tetramethylbenzene
1.50
1.45
1.54


Pentylbenzene
7.12
7.23
6.63


Naphthalene
1.68
1.48
1.81


C11 Aromatic
25.45
25.63
23.68


Pentamethylbenzene
0.02
0.02
0.02


2-Methylnaphthalene
0.02
0.02
0.02


1-Methylnaphthalene
0.01
0.01
0.01


Unidentified
1.78
2.10
1.71



100.00
100.00
100.00










Summary by Group










Totals
Group
% Wt
% Vol






Paraffin
0.00
0.00



Isoparaf.
0.00
0.00



Olefin
0.00
0.00



Naphthene
0.00
0.00



Aromatic
98.22
97.90



Oxygenates
0.00
0.00



Unidentified
1.78
2.10




100.00
100.00










Summary by Carbon










Totals
Group
% wt
% Vol






C4
0.00
0.00



C5
0.00
0.00



C6
0.00
0.00



C7
0.00
0.00



C8
0.00
0.00



C9
3.63
3.56



C10
61.76
61.22



C11
32.83
33.12



C12
0.00
0.00










Composition by Carbon










Group
C#
% wt
% Vol





Paraffin






C4
0.00
0.00



C5
0.00
0.00



C6
0.00
0.00



C7
0.00
0.00



C8
0.00
0.00



C9
0.00
0.00



C10
0.00
0.00



C11
0.00
0.00



C12
0.00
0.00


isoparaf.
C4
0.00
0.00



C5
0.00
0.00



C6
0.00
0.00



C7
0.00
0.00



C8
0.00
0.00



C9
0.00
0.00



C10
0.00
0.00



C11
0.00
0.00



C12
0.00
0.00


Olefin
C4
0.00
0.00



C5
0.00
0.00



C6
0.00
0.00



C7
0.00
0.00



C8
0.00
0.00



C9
0.00
0.00



C10
0.00
0.00



C11
0.00
0.00


Naphthene
C4





C5
0.00
0.00



C6
0.00
0.00



C7
0.00
0.00



C8
0.00
0.00



C9
0.00
0.00



C10
0.00
0.00



C11
0.00
0.00


Aromatic
C6
0.00
0.00



C7
0.00
0.00



C8
0.00
0.00



C9
3.63
3.56



C10
61.76
61.22



C11
32.83
33.12



C12
0.00
0.00









The compositional analysis of another typical Aromatic-150 blendstock is given in Table 3.







TABLE 3







Sample ID Total Aromatic 150













WT %
LV %
MOL %
















Ortho-Xylene
0.01
0.01
0.01



n-Propylbenzene
0.03
0.03
0.04



1-Methyl-3-ethylbenzene
0.10
0.10
0.12



1-Methyl-4-ethylbenzene
0.06
0.06
0.07



1,3,5-Trimethylbenzene
0.11
0.11
0.13



1-Methyl-2-ethylbenzene
0.14
0.14
0.16



1,2,4-Trimethylbenzene
1.26
1.27
1.48



Cis 1,3 diethylcyclohexane
0.01
0.01
0.01



Isobutylbenzene
0.06
0.06
0.06



sec-Butylbenzene
0.07
0.07
0.07



N-Decane
0.03
0.04
0.03



1,2,3-Trimethylbenzene
1.51
1.49
1.77



1-Methyl-3-isopropylbenzene
0.15
0.15
0.16



1-Methyl-4-isopropylbenzene
0.07
0.07
0.07



Indan (2,3-Dihydroindene)
0.53
0.48
0.63



Sec-butylcyclohexane
0.01
0.01
0.01



1-Methyl-2-isopropylbenzene
0.03
0.03
0.03



Butylcyclohexane
0.64
0.70
0.64



1-Methyl-3-n-propylbenzene
2.18
2.23
2.29



1-Methyl-4-n-propylbenzene
0.76
0.78
0.80



1,4-Diethylbenzene
1.71
1.74
1.80



1,3-Dimethyl-5-ethylbenzene
2.45
2.48
2.57



1,2-Diethylbenzene
0.20
0.20
0.21



1-Methyl-2-n-propylbenzene
1.69
1.70
1.78



5-Methyldecane
0.03
0.04
0.03



2-Methyldecane
0.04
0.05
0.04



1,4-Dimethyl-2-ethylbenzene
3.09
3.09
3.25



1,3-Dimethyl-4-ethylbenzene
0.52
0.52
0.55



3-Methyldecane
0.02
0.02
0.02



1-Methyldecane
7.37
6.84
7.86



1,2-Dimethyl-4-ethylbenzene
3.42
3.44
3.59



1,3-Dimethyl-2-ethylbenzene
0.03
0.03
0.03



1,2-Dimethyl-3-Ethylbenzene
2.66
2.62
2.79



N-Undecane
0.38
0.45
0.34



1,2,4,5-Tetramethylbenzene
7.02
6.98
7.37



1,2,3,5-Tetramethylbenzene
10.74
10.61
11.28



4-Methylindan
3.33
3.09
3.55



5-Methylindan
3.08
2.86
3.28



1,2,3,4-Tetramethylhenzene
5.04
4.91
5.29



Pentylbenzene
1.79
1.83
1.70



1,1 Dimethylindan
0.63
0.59
0.61



1.2 Dimethylindan
2.51
2.34
2.42



1,6 Dimethylindan
1.34
1.25
1.29



C11 Aromatic
18.98
19.30
18.05



1,3,5-triethylbenzene
0.27
0.28
0.23



1,3 Dimethylindan
0.77
0.72
0.74



5,6 Dimethylindan
0.61
0.57
0.59



1,2,4-triethylbenzene
0.42
0.42
0.36



4,5 Dimethylindan
0.24
0.22
0.23



Tridecanes
9.58
10.45
7.72



Tetradecanes
1.64
1.76
1.22



Pentadecanes
0.12
0.13
0.08



Unidentified
0.52
0.63
0.55



Total
100.00
100.00
100.00



Total Paraffins
0.41
0.49
0.37



Total Isoparaffins
0.09
0.11
0.09



Total Naphthenes
0.66
0.72
0.66



Total Aromatics
86.98
85.71
89.31



Unclassified
11.86
12.97
9.57



Total C8
0.01
0.01
0.01



Total C9
3.74
3.68
4.40



Total C10
56.36
55.26
59.37



Total C11
27.34
27.38
26.06



Total C12
0.69
0.70
0.59



C10 Paraffin
0.03
0.04
0.03



C11 Paraffin
0.38
0.45
0.34



C11 Isoparaffin
0.09
0.11
0.09



C10 Naphthene
0.66
0.72
0.66



C8 Aromatic
0.01
0.01
0.01



C9 Aromatic
3.74
3.68
4.40



C10 Aromatic
55.67
54.50
58.68



C11 Aromatic
26.87
26.82
25.63



C12 Aromatic
0.69
0.70
0.59










The C6-C10+ aromatic distribution and distillation profile for yet another typical Aromatic-150 blendstock is given in Table 4.










TABLE 4





TEST
METHOD
UNITS
RESULTS


















Distillation - IBP
ASTM D86
° F.
372


5%

° F.
378


10%

° F.
379


20%

° F.
380


30%

° F.
380


40%

° F.
381


50%

° F.
382


60%

° F.
383


70%

° F.
384


80%

° F.
385


90%

° F.
388


95%

° F.
390


Distillation - EP

° F.
407


Recovery

vol %
98.8


Residue

vol %
1.1


Loss

vol %
0.1


Gravity
ASTM D4052
API
26.9


Density @ 60° F.
ASTM D4052
kg/m3
892.5


Reid Vapor Pressure
ASTM D5191
psi
n/a


Sulfur
ASTM D5453
wt %
<1


Aromatics. Total
ASTM D6733
vol %
98.8


C9 Aromatics
ASTM D6733
vol %
0.7


C10 Aromatics
ASTM D6733
vol %
60.5


C11 Aromatics
ASTM D6733
vol %
37.6


Peroxide Content
ASTM D3703
ppm
<1


Flash Point
ASTM D93A
° F.
10.8









A distillation profile for a tetralin blendstock is shown in Table 5. The relatively narrow distillation range suggests that the tetralin blendstock is comprised mostly of tetralin with only relatively minor amounts of isomers and components having slightly lower or slightly higher molecular weights being present.












TABLE 5







TEST
METHOD
UNITS
RESULTS





















Distillation - IBP
ASTM D86
° C.
199



5%

° C.
202.6



10%

° C.
202.7



20%

° C.
202.8



30%

° C.
202.9



40%

° C.
203



50%

° C.
203.1



60%

° C.
203.1



70%

° C.
203.2



80%

° C.
203.4



90%

° C.
203.7



95%

° C.
204.4



Distillation - EP

° C.
219.3



Recovery

vol %
99



Residue

vol %
1



Loss

vol %
0



Gravity @ 15.56° C.
ASTM D4052
° API
13.95










A distillation profile for a diethylbenzene blendstock is shown in Table 6. The relatively narrow distillation range suggests the diethylbenzene blendstock is comprised mostly of diethylbenzene, with only relatively minor amounts of isomers and components having slightly lower or slightly higher molecular weights being present.












TABLE 6







TEST
METHOD
UNITS
RESULTS





















Distillation - IBP
ASTM D86
° F.
353.0



5%

° F.
353.2



10%

° F.
353.3



20%

° F.
353.5



30%

° F.
353.7



40%

° F.
353.9



50%

° F.
354.1



60%

° F.
354.3



70%

° F.
354.5



80%

° F.
354.7



90%

° F.
355.0



95%

° F.
355.6



Distillation - EP

° F.
371.6



Recovery

vol %
99.2



Residue

vol %
0.8



Loss

vol %
0.0



API Gravity
ASTM
° API
31.6




D4052





Specific Gravity
ASTM
—
0.8676




D4052










It is a relatively simple matter to determine the C6-C10+ distributions of aromatic species in the various aromatic refinery blendstocks, and determine appropriate amounts thereof that can be blended to obtain a final aromatic pre-blend having the desired C6-C10+ distribution.
The distribution of aromatic components (C6, C7, C8, C9 and C10+) for an aromatic pre-blend prepared in accordance with this disclosure, as determined analytically, is compared with the target aromatic component distribution from 40 CFR 1065.710(b) in Table 7.











TABLE 7










Target













TEST
METHOD
UNITS
MIN
MAX
Results














Gravity @ 60° F.
ASTM D4052
° API
Report
30.1


Density @ 15.56° C.
ASTM D4052
g/mL
Report
0.8756












Composition, aromatics
ASTM D5769






C6 aromatics (benzene)

vol %

0.1
0.05


C7 aromatics (toluene)

vol %
23.5
26.0
24.6


C8 aromatics

vol %
23.5
25.0
25.0


C9 aromatics

vol %
25.0
27.0
26.3


C10+ aromatics

vol %
23.0
26.0
24.8









A compositional analysis for another aromatic pre-blend prepared in accordance with this disclosure is given in Table 8.










TABLE 8






WT %
LV %
MOL %


















Benzene
0.01
0.01
0.01


Toluene
23.27
23.31
28.44


N-Octane
0.01
0.01
0.01


Ethylcyclohexane
0.01
0.01
0.01


Ethylbenzene
3.14
3.15
3.33


Meta-Xylene
10.85
10.91
11.51


Para-Xylene
4.08
4.12
4.33


2-Methyloctane
0.01
0.01
0.01


3-Methyloetane
0.01
0.01
0.01


Ortho-Xylene
5.15
5.09
5.46


N-Nonane
0.01
0.01
0.01


Isopropylbenzene
0.05
0.05
0.05


n-Propylbenzene
0.14
0.14
0.13


1-Methyl-3-ethylbenzene
0.22
0.22
0.21


1-Methyl-4-ethylbenzene
0.23
0.23
0.22


1,3,5-Trimethylbenzene
0.05
0.05
0.05


1-Methyl-2-ethylbenzene
0.10
0.10
0.09


1,2,4-Trirnethylbenzene
26.49
26.29
24.82


Isobutylbenzene
0.04
0.04
0.03


sec-Butylbenzene
0.06
0.06
0.05


N-Decane
0.01
0.01
0.01


1,2,3-Trimethylbenzene
0.05
0.05
0.05


1-Methyl-3-isopropylbenzene
0.04
0.04
0.03


Indan (2,3-Dihydroindene)
0.01
0.01
0.01


1,3-Diethylbenzene
9.36
9.41
7.85


1,4-Diethylbenzene
12.59
12.68
10.56


1,2-Diethylbenzene
0.03
0.03
0.03


1-Methylindan
0.06
0.06
0.05


1,2-Dimethyl-3-Ethylbenzene
0.02
0.02
0.02


1,2,4.5-Tetramethylbenzene
0.02
0.02
0.02


1,2,3,5-Tetramethylbenzene
0.01
0.01
0.01


4-Methylindan
0.02
0.02
0.02


5-Methylinclan
0.01
0.01
0.01


Pentylbenzene
0.02
0.02
0.02


Naphthalene
0.31
0.27
0.27


C11 Aromatic
0.01
0.01
0.01


N-Dodecane
0.01
0.01
0.01


1,3,5-triethylbenzene
0.02
0.02
0.01


5,6 Dimethylindan
0.07
0.06
0.05


2-Methylnaphthalene
0.82
0.75
0.65


4,5 Dimethylindan
0.05
0.05
0.04


Tridecanes
0.24
0.26
0.15


1-Methylnaphthalene
0.39
0.33
0.31


Tetradecanes
0.19
0.20
0.11


Pentadecanes
0.73
0.77
0.40


Hexadecanes
0.41
0.43
0.21


N-Hexadecane
0.03
0.03
0.01


Heptadecanes
0.25
0.26
0.12


N-Heptadecane
0.01
0.01
0.00


Pristane
0.01
0.01
0.00


Octadecanes
0.04
0.04
0.02


Unidentified
0.23
0.28
0.16


Total
100.00
100.00
100.00


Total Paraffins
0.04
0.04
0.04


Total Isoparaffins
0.02
0.02
0.02


Total Naphthenes
0.01
0.01
0.01


Total Aromatics
97.79
97.64
98.75


Unclassified
2.14
2.29
1.18


Total C6
0.01
0.01
0.01


Total C7
23.27
23.31
28.44


Total C8
23.24
23./9
24.65


Total C9
27.37
27.17
25.66


Total C10
22.58
22.68
18.96


Total C11
1.36
1.22
1.08


Total C12
0.03
0.03
0.02


C8 Paraffin
0.01
0.01
0.01


C9 Paraffin
0.01
0.01
0.01


C10 Paraffin
0.01
0.01
0.01


C12 Paraffin
0.01
0.01
0.01


C9 Isoparaffin
0.02
0.02
0.02


C8 Naphthene
0.01
0.01
0.01


C6 Aromatic
0.01
0.01
0.01


C7 Aromatic
23.27
23.31
28.44


C8 Aromatic
23.22
23.27
24.63


C9 Aromatic
27.34
27.14
25.63


C10 Aromatic
22.57
22.67
18.95


C11 Aromatic
1.36
1.22
1.08


C12 Aromatic
0.02
0.02
0.01


Mol WT of Sample, gm/mol 112.59





Density of Sample, gm/cc 0.874









Total aromatics, aromatic distribution (C6, C7, C8, C9 and C10+ aromatics) and distillation profile for two additional aromatic pre-blends (DG2421BE10 and TILX353058) prepared in accordance with this disclosure are shown in Table 9.







TABLE 9







PRODUCT: Aromatic Pre-blend DG2421BE10 TILX 353058











TEST
METHOD
UNITS
RESULTS
RESULTS














Distillation - IBP
ASTM D86
° F.
254.0
254.4


5%

° F.
268.9
267.9


10%

° F.
271.4
271.6


20%

° F.
277.7
277.9


30%

° F.
285.0
286.0


40%

° F.
294.5
295.4


50%

° F.
305.6
305.9


60%

° F.
317.4
317.4


70%

° F.
328.6
328.4


80%

° F.
338.5
338.6


90%

° F.
351.3
350.5


95%

° F.
368.7
368.4


Distillation - EP

° F.
437.8
427.6


Recovery

vol %
97.8
97.8


Residue

vol %
1.0
1.0


Loss

vol %
1.2
1.2


Gravity
ASTM D4052
° API
30.10
30.20


Specific Gravity
ASTM D4052
—
0.8756
0.8751


C6 aromatics 
ASTM 05769
vol %
0.05
0.05


(benzene)






C7 aromatics 
ASTM D5769
vol %
24.6
26.0


(toluene)






C8 aromatics
ASTM 05769
vol %
25.0
24.4


C9 aromatics
ASTM D5769
vol %
26.25
26.45


C10+ aromatics
ASTM 05769
vol %
24.80
21.40









The aromatic pre-blend can then be combined with one or more paraffinic refinery blendstocks comprised primarily of paraffinic (saturated) species and having a low aromatic content (e.g., less than 5 volume percent) to obtain a mixture meeting most of the compositional, distillation profile, and fuel quality characteristics specified in 40 CFR 1065.710(b).
The specifications for an E10 test fuel in accordance with 40 CFR 1065.710(b) is given in Table 10.










TABLE 10









SPECIFICATION
















Low-
High





General
Temperature
Altitude
Reference


Property
Unit
Testing
Testing
Testing
Procedure














Antiknock Index
—
87.0-88.4
87.0
ASTM D2699


(R + M)/2


Minimum
and D2700










Sensitivity (R − M)
—
7.5 Minimum
ASTM D2699





and D2700












Dry Vapor
kPa (psi)
60.0-63.4
77.2-81.4
52.4-55.2
ASTM D5191


Pressure

(8.7-9.2) 
(11.2-11.8)
(7.6-8.0)



Equivalent







(DVPEf







Distillationc
° C. (° F.)
49-60
43-54 (110-
49-60 
ASTM D86


10% evaporated

(120-140)
130)
(120-140)











50% evaporated
° C. (° F.)
88-99 (190-210)



90% evaporated
° C. (° F.)
157-168 (315-335)



Evaporated final
° C. (° F.)
193-216 (380-420)



boiling point





Residue
milliliter
2.0 Maximum



Total Aromatic
volume %
21.0-25.0
ASTM D5769


Hydrocarbons





C6 Aromatics
volume %
0.5-0.7



(benzene)





C7 Aromatics
volume %
5.2-6.4



(toluene)





C8 Aromatics
volume %
5.2-6.4



C9 Aromatics
volume %
5.2-6.4



C10+ Aromatics
volume %
4.4-5.6



Olefins5
mass %
4.0-10.0
ASTM D6550


Ethanol blended
volume %
9.6-10.0
See





§1065.710(b)(3)


Ethanol
volume %
9.4-10.2
ASTM D4815 or


confirmatoryr


D5599


Total Content of 
volume %
0.1 Maximum
ASTM D4815 or


Oxygenates Other


D5599


than Ethanolf





Sulfur
mg/kg
8.0-11.0
ASTM D2622,





D5453 or D7039


Lead
g/liter
0.0026 Maximum
ASTM D3237


Phosphorus
g/liter
0.0013 Maximum
ASTM D3231


Copper Corrosion
—
No. I Maximum
ASTM D130


Solvent-Washed
mg/100
3.0 Maximum
ASTM D381


Gum Content
milliliter




Oxidation Stability
minute
1000 Minimum
ASTM D525









To the extent that vapor pressure, olefin content, or sulfur requirements are not within the specification, butane may be added to adjust vapor pressure, olefins (such as butene) may be added to adjust olefin content, and sulfur compounds may be added to adjust sulfur content, such that the resulting composition is fully compliant with 40 CFR 1065.710(b).
Table 11 lists the test results for an E10 test fuel prepared in accordance with the methods disclosed herein.









TABLE 11








EPA Tier 3 EEE




Emission 




Certification Fuel,
Batch No.: DE1821LT10



General Testing -
Tank No.:107











PRODUCT:
Regular 

SPECIFICATIONS














TEST
METHOD
UNITS
MIN 
TARGET
MAX
RESULTS
















Distillation - IBP
ASTM D86
° F.



97.7


5%

° F.



123.9


10%

° F.
120

140
131.3


20%

° F.



139.9


30%

° F.



146.7


40%

° F.



152.9


50%

° F.
190

210
193.3


60%

° F.



225.0


70%

° F.



248.8


80%

° F.



274.8


90%

° F.
315

335
315.9


95%

° F.



336.9


Distillation - EP

° F.
380

420
380.3


Recovery

ml

Report

98.0


Residue

ml


2.0
1.1


Loss

ml

Report

1.0


Gravity @ 60° F.
ASTM D4052
° API

Report

58.52


Density 169 15.56° C.
ASTM D4052
—

Report

0.7440


Reid Vapor Pressure 
ASTM D5191
psi
8.7

9.2
9.1


EPA Equation








Carbon
ASTM D5291
wt fraction

Report

0.8262


Hydrogen
ASTM D5291
wt fraction

Report

0.1368


Hydrogen/Carbon ratio
ASTM D5291
mole/mole

Report

1.973


Oxygen
ASTM D4815
wt %

Report

3.70


Ethanol content
ASTM D5599-00
vol %
9.6

10.0
9.9


Total oxygentates other 
ASTM D4815
vol %


0.1
NoneDetected


than ethanol








Sulfur
ASTM D5453
mg/kg
8.0

11.0
10.1


Phosphorus
ASTM D3231
g/l


0.0013
None Detected


Lead
ASTM D3237
g/l


0.0026
None Detected


Composition, aromatics
ASTM D5769
vol %
21.0

25.0
23.3


C6 aromatics (benzene)
ASTM D5769
vol %
0.5

0.7
0.6


C7 aromatics (toluene)
ASTM D5760
vol %
5.2

6.4
5.9


C8 aromatics
ASTM D5769
vol %
5.2

6.4
6.1


C9 aromatics
ASTM D5769
vol % 
5.2

6.4
5.6


C10+ aromatics
ASTM D5769
vol %
4.4

5.6
5.1


Composition, olefins
ASTM D6550
wt %
4.0

10.0
5.8


Oxidation Stability
ASTM D525
minutes
1000


1000+


Copper Corrosion
ASTM D130



1
1a


Existent gum, washed
ASTM D381
mg/100 mls


3.0
1.0


Existent gum, unwashed
ASTM D381
mg/100 mls

Report

1.5


Research Octane Number
ASTM D2699


Report

92.1


Motor Octane Number
ASTM D2700


Report

83.7


R + M/2
D2699/2700

87.0

88.4
87.9


Sensitivity
D2699/2700

7.5


8.4


Net Heat of Combustion
ASTM D240
BTU/lb

Report

17954









The described embodiments are not limiting. Various modifications are considered within the purview and scope of the appended claims.

## Claims

1. A process for preparing E10 test fuel in accordance with 40 CFR 1065.710(b), comprising:
(a) providing an aromatic pre-blend prepared by mixing aromatic refinery blendstocks in proportions that are appropriate to meet the C6 aromatic, C7 aromatic, C8 aromatic, C9 aromatic and C10+ aromatic contents of 40 CFR 1065.710(b);
(b) combining the aromatic pre-blend with at least one paraffinic refinery blendstock having a paraffin (saturates) content of at least 93 volume percent, an aromatic content less than 10 volume percent, an initial boiling point of at least 82 degrees Fahrenheit, and a final boiling point from 380 degrees Fahrenheit to 435 degrees Fahrenheit, the aromatic pre-blend, and refinery blendstock being mixed with ethanol in proportions effective to achieve the specified aromatic distribution, total aromatics content, ethanol content and distillation profile of 40 CFR 1065.710(b); and
(c) optionally adding butane, olefin-containing blendstocks, and sulfur compounds or sulfur-containing blendstocks as needed to meet the requirements of 40 CFR 1065.710(b).

2. A process for preparing E10 test fuel in accordance with 40 CFR 1065.710(b), comprising:
(a) providing an aromatic pre-blend prepared by mixing aromatic refinery blendstocks in proportions that are appropriate to meet the C6 aromatic, C7 aromatic, C8 aromatic, C9 aromatic and C10+ aromatic contents of 40 CFR 1065.710(b);
(b) combining the aromatic pre-blend with at least one paraffinic refinery blendstock having a paraffin (saturates) content of at least 93 volume percent, an aromatic content less than 10 volume percent, an initial boiling point of at least 82 degrees Fahrenheit, and a final boiling point from 380 degrees Fahrenheit to 435 degrees Fahrenheit, the aromatic pre-blend, and refinery blendstock being mixed with ethanol in proportions effective to achieve the specified aromatic distribution, total aromatics content, ethanol content and distillation profile of 40 CFR 1065.710(b); and
(c) optionally adding butane, olefin-containing blendstocks, and sulfur compounds or sulfur-containing blendstocks as needed to meet the requirements of 40 CFR 1065.710(b), wherein the aromatic pre-blend is formulated to have a C7:C6 aromatic volume basis ratio of 5.2-6.4:0.5-0.7, a C8:C6 aromatic volume basis ratio of 5.2-6.4:0.5-0.7, a C9:C6 aromatic volume basis ratio of 5.2-6.4:0.5-0.7, and a C10+:C6 aromatic volume basis ratio of 4.4-5.6:0.5-0.7.

3. A process for preparing E10 test fuel in accordance with 40 CFR 1065.710(b), comprising:
mixing aromatic refinery blendstocks with at least one paraffinic refinery blendstock, wherein the aromatic refinery blendstocks are selected such that if blended together without the at least one paraffinic refinery blendstock a resulting aromatic refinery blendstock mixture would comprise aromatic compounds in proportions as specified in 40 CFR 1065.710(b); and
optionally adding ethanol, butane, olefin-containing blendstocks and sulfur compounds or sulfur-containing blendstocks as needed to meet the requirements of 40 CFR 1065.710(b), wherein the aromatic refinery blendstock is formulated to have a C7:C6 aromatic volume basis ratio of 5.2-6.4:0.5-0.7, a C8:C6 aromatic volume basis ratio of 5.2-6.4:0.5-0.7, a C9:C6 aromatic volume basis ratio of 5.2-6.4:0.5-0.7, and a C10+:C6 aromatic volume basis ratio of 4.4-5.6:0.5-0.7.