U.S. patent application number 12/444339 was filed with the patent office on 2010-01-21 for light oil composition.
This patent application is currently assigned to Toyota Jidosha Kabushiki Kaisha. Invention is credited to Keiko Fukumoto, Hitoshi Hayashi, Atsushi Murase, Tadao Ogawa, Ayako Ohshima, Eiichi Sudo.
Application Number | 20100012551 12/444339 |
Document ID | / |
Family ID | 39282837 |
Filed Date | 2010-01-21 |
United States Patent
Application |
20100012551 |
Kind Code |
A1 |
Hayashi; Hitoshi ; et
al. |
January 21, 2010 |
LIGHT OIL COMPOSITION
Abstract
The invention provides a light oil composition that does not
cause deterioration in a Nylon-based material. Specifically, the
invention provides a light oil composition containing paraffin(s)
at a concentration of 97% by mass or more, wherein the content of
isoparaffin(s) having 14 or fewer carbon atoms in the paraffin(s)
is 10% by mass or less.
Inventors: |
Hayashi; Hitoshi;
(Toyota-shi, JP) ; Ogawa; Tadao; (Kasugai-shi,
JP) ; Sudo; Eiichi; (Aichi-gun, JP) ; Ohshima;
Ayako; (Nishikamo-gun, JP) ; Fukumoto; Keiko;
(Aichi-gun, JP) ; Murase; Atsushi; (Nagoaya-shi,
JP) |
Correspondence
Address: |
SUGHRUE MION, PLLC
2100 PENNSYLVANIA AVENUE, N.W., SUITE 800
WASHINGTON
DC
20037
US
|
Assignee: |
Toyota Jidosha Kabushiki
Kaisha
Toyota-shi, Aichi
JP
|
Family ID: |
39282837 |
Appl. No.: |
12/444339 |
Filed: |
October 5, 2007 |
PCT Filed: |
October 5, 2007 |
PCT NO: |
PCT/JP2007/069584 |
371 Date: |
April 3, 2009 |
Current U.S.
Class: |
208/17 |
Current CPC
Class: |
C10G 2/00 20130101; C10L
1/08 20130101 |
Class at
Publication: |
208/17 |
International
Class: |
C10L 1/04 20060101
C10L001/04 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 6, 2006 |
JP |
2006-275311 |
Claims
1. A light oil composition comprising paraffin(s) at a
concentration of 97% by mass or greater, wherein the paraffin(s)
comprise isoparaffin(s) having 14 or fewer carbon atoms at a
concentration of 10% by mass or less.
2. The light oil composition according to claim 1, further
comprising highly branched isoparaffin(s) having 15 or more carbon
atoms.
Description
TECHNICAL FIELD
[0001] The present invention relates to a light oil composition,
and in particular to a GTL (Gas to Liquid) light oil
composition.
BACKGROUND ART
[0002] There has been a lot of research relating to particulate
matter (PM) undertaken since reports in the 1970s of the
carcinogenic nature of particulate matter (PM) discharged from
diesel vehicles. Measures to reduce PM include: for vehicles,
developments such as increasing fuel injection to a higher
pressure, and post-processing systems for exhaust gas; and for
light oils there has been progress in reducing the sulfur content
thereof. City light oil (Class-1), like that use in Sweden since
1993, is a representative example of a low sulfur light oil (see
for example Non-Patent Document 1).
[0003] The use of GTL light oil has been receiving a lot of
attention from the perspective of reducing the amount of PM
discharge. GTL light oil is a synthetic oil fraction with a boiling
point within the range of that of light oil obtained by: conversion
of natural gas and heavy oil into a water gas; synthesis thereof
using a Fischer-Tropsch reaction (FT synthesis); fractionating off
the highly volatile components of this synthetic oil; and carrying
out hydrocracking and isomerization as required.
[0004] Such a GTL light oil was produced in Germany during the
Second World War, however production was halted thereafter.
Interest in GTL light oils was rekindled in the late 1980s as the
problems of environmental pollution became of global importance.
Production of GTL light oil was restarted in 1992 by a South
African company, Mossgas. Since 1998 when Melinda da Sirman of SwRI
reported at an SAE international conference that GTL light oils
have the lowest amounts of PM discharge (see for example Non-Patent
Documents 2 and 3) the US Department of Energy, oil majors etc.
have shown interest therein, so that GTL plants are now to be built
in every region of the world.
[0005] Global production of GTL light oils is currently at 100,000
barrels a day, and when all of the plants currently under
construction are in operation in 2010 this amount is said to become
600,000 barrels a day (this is equivalent to the total consumption
of light oils in Japan) (see for example Non-Patent Document
4).
[0006] Non-patent document 1: Sweden Class-1: R. F. Tucker, R. J.
Stradling, P. E. Wolveridge, K. J. Rivers and A. Ubbens, The
Lubricty of Deeply Hydrogenated Diesel Fuels--The Swedish
Experience, SAE942016
[0007] Non-patent document 2: Noboru Kawada, Outlook for the Next
Generation of Synthetic Fuel Oils (First) "Quality Trends in
Petroleum Products, and Issues with Existing Refining Techniques",
Petrotech, 23, (12) pp 1061 to 1066
[0008] Non-patent document 3: Kaoru Fujimoto, Seiichi Kiryu,
Outlook for the Next Generation of Synthetic Fuel Oils (Third)
"Trends in Technical Developments for FT Synthesis", Petrotech, 24,
(2) pp 113 to 118
[0009] Non-patent document 4: Yukihiro Tsukasaki, Recent Trends in
Vehicle GTL Fuels, Vehicle Technology, 55, (5), pp. 67-72,
(2001)
DISCLOSURE OF INVENTION
Problem to be Solved by the Invention
[0010] While it is thought that from now on GTL light oils will
steadily become more widely used, the effect of GTL light oils on
fuel system materials is hardly known at all. We have investigated
the effect of GTL light oils on resins and rubbers used in the fuel
systems of diesel vehicles. As a result of immersing resins and
rubbers in GTL light oils and carrying out tensile tests thereon,
we have determined that there is a large decrease in the extension
of Nylon-66 that has been immersed in a standard GTL light oil.
Since up to now Nylon has been widely known as a
hydrocarbon-resistant material, the phenomenon of the large
reduction in the extension of Nylon that has been immersed in a GTL
light oil is a completely unexpected result.
[0011] There has not been an interval of time since GTL light oils
have been used commercially, and so there are no reports of
investigations into the effects of GTL light oils on fuel systems.
Consequently the effect of GTL light oils on the deterioration of
Nylon is completely unpredictable, and there is an urgent
requirement to develop a GTL light oil that does not cause
deterioration in Nylon, in light of the expected large increase in
demand for GTL light oils.
[0012] Therefore, the objective of the present invention is to
address the above issue. Namely, objective of the present invention
is to provide a light oil composition that does not cause
deterioration in Nylon-based materials.
Method of Solving the Problem
[0013] As a result of diligent research into solving the above
problem, the inventors have arrived at the present invention and
discovered that the above problem can be solved. Namely, the
present invention is a light oil composition containing paraffin(s)
at a concentration of 97% by mass or greater, with isoparaffin(s)
having 14 or fewer carbon atoms at a concentration of 10% by mass
or less of the above paraffin(s).
EFFECT OF THE INVENTION
[0014] According to the present invention, a light oil composition
that does not cause deterioration in Nylon-based materials can be
provided.
BRIEF DESCRIPTION OF DRAWINGS
[0015] FIG. 1 is a diagram showing the dissolved oxygen amount
before and after immersion in GTL light oils.
[0016] FIG. 2 is a diagram showing the dissolved oxygen amount
before and after immersion in paraffins.
[0017] FIG. 3 are diagrams showing total ion chromatograms using
thermal desorption-GC/MS, (A) is Nylon that has been immersed in
Test Sample-A, and (B) is Nylon that has been immersed in Test
Sample-B.
[0018] FIG. 4 are diagrams showing MALDI-MS mass spectra of Nylon,
(A) is untreated Nylon, (B) is Nylon that has been immersed in Test
Sample-B, (C) is Nylon that has been immersed in Test Sample-A, (D)
is Nylon subjected to oxidizing treatment, and (E) is Nylon
subjected to hydrolysis treatment.
[0019] FIG. 5 is a diagram showing results of analysis of Nylons in
the depth direction.
[0020] FIG. 6 are diagrams showing the results of IR imaging
analysis of Nylons in the depth direction, (A) is Nylon that has
been immersed in Test Sample-A, and (B) is Nylon that has been
immersed in Test Sample-B.
[0021] FIG. 7 are diagrams showing the results of analysis by gas
chromatographic/mass spectroscopic methods of model fuels before
and after immersion, (A) is for types of paraffin, (B) is for
oxidation products (alcohols).
[0022] FIG. 8 is a diagram showing Nylon analyzed by thermal
desorption-gas chromatographic/mass spectroscopic methods before
and after immersion.
[0023] FIG. 9 is a diagram showing the relationship between
isoparaffin concentration and extension at breakage.
BEST MODE FOR CARRYING OUT THE INVENTION
[0024] The present invention is a light oil composition, and in
particular, a GTL light oil or a light oil composition containing a
GTL light oil, wherein paraffin(s) are contained at a concentration
of 97% by mass or greater, and isoparaffin(s) having 14 or fewer
carbon atoms are contained in the above paraffin(s) at a
concentration of 10% by mass or less. If the concentration of
isoparaffin(s) is less than 97% by mass, then it ceases to be
called a clean fuel due to the PM discharge properties and the
like. If bio light oil were to be permitted, then deterioration of
the fuel itself and deterioration of other materials becomes a
problem. If the concentration of the isoparaffin(s) having 14 or
fewer carbon atoms exceeds 10% by mass, then Nylon materials used
in fuel systems oxidize, and become low molecular weight molecules
by being depolymerized or reduce the extension thereof, leading to
deterioration in Nylon-based materials.
[0025] By the way, the presence of isoparaffins lowers the cetane
number of GTL light oils (lowers the too high cetane number of
normal paraffins), and also exhibits the effect of lowering the
viscosity. Consequently, a highly branched isoparaffin having 15 or
more carbon atoms is preferably added if the viscosity of the light
oil of the present invention becomes too high, thereby adjusting
the viscosity. There is no particular limitation to the amount
contained of the highly branched isoparaffin having 15 or more
carbon atoms as long as the resultant has the desired viscosity and
cetane number.
[0026] The light oil of the present invention can, for example, be
manufactured as described below. Namely, manufacture is by
hydrocracking paraffin obtained by FT reaction (Fischer-Tropsch
reaction) over a solid acid catalyst to obtain an isoparaffin. This
isoparaffin is next analyzed by gas chromatography and the
concentration of isoparaffin(s) having 14 or fewer carbon atoms is
investigated. An addition amount is decided in consideration of the
gas chromatography-analyzed concentration of isoparaffin(s) having
14 or fewer carbon atoms (such that the isoparaffin concentration
is 10% by mass or less after mixing) and the above isoparaffin is
then mixed with the paraffin obtained by FT reaction.
[0027] The light oil of the present invention such as above has the
following advantages.
(1) By composing a GTL light oil as in the present invention, there
is no need to change the Nylon-based materials used in current fuel
systems, and application can be made to diesel vehicles. (2) When
the GTL light oil of the present invention is mixed with a current
light oil, there is also no need to change the Nylon-based
materials used in current fuel systems, and application can be made
to diesel vehicles. (3) By switching light oil to GTL light oil or
to a GTL light oil composition, the emissions of diesel vehicles
can be made clean.
EXAMPLES
[0028] More specific explanation will be given of the present
invention below by way of Test Samples and Examples, however the
present invention is not limited thereto.
Test Example 1
[0029] Two types of GTL light oil having different concentrations
of low molecular weight (low number of carbon atoms) paraffin were
prepared (Simulation Test Sample-A and Simulation Test Sample-B).
Test Sample-A was prepared to include a greater amount of low
molecular weight paraffin in comparison to Test Sample-B, and this
composition was confirmed using a GC method.
[0030] Next the dissolved oxygen amount in Test Sample-A and Test
Sample-B was derived using a gas chromatography method (mounted to
a thermal conductivity detector) with a 3 meter long column packed
with molecular sieve 13X. The results are shown in FIG. 1. It is
clear from FIG. 1 that the dissolved oxygen amount of Test Sample-A
is greater in comparison to that of Test Sample-B. This is thought
to be because the Test Sample-A contains a greater amount of low
molecular weight isoparaffin than Test Sample-B.
[0031] The dissolved oxygen amount was measured for normal
paraffins and isoparaffins (2-methyl paraffin) having 8 to 12
carbon atoms. The results are shown in FIG. 2. The dissolved oxygen
concentration at room temperature is shown on the vertical axis of
FIG. 2 (in a similar manner to FIG. 1). It can be seen from FIG. 2
that (1) isoparaffin contains a greater amount of oxygen than
normal paraffin, and (2) for the same type of paraffin, the smaller
the number of carbon atoms the more oxygen is contained.
[0032] Nylon-66 (referred to below simply as Nylon) was immersed in
Test Sample-A and in Test Sample-B, respectively. After immersion
for 500 hours the surface layer was removed from each Nylon and
heated to 250.degree. C. in Helium, and any gas generated was
analyzed by gas chromatographic/mass spectroscopic methods. The
results thereof are shown in FIG. 3.
[0033] It can be seen from FIG. 3 that (1) Nylon that had been
immersed in Test Sample-A contained more low molecular weight
paraffin than Nylon that had been immersed in Test Sample-B. In
addition, it can be seen that (2) the paraffin that had permeated
into the Nylon had a higher proportion of isoparaffin than the
original Test Sample.
[0034] Samples extracted from the surface of each of the Nylons
above were analyzed using Matrix Assisted Laser Desorption
Ionisation Mass Spectrometry (MALDI-MS). In addition similar
analysis was carried out on untreated Nylon (FIG. 4A), Nylon
subjected to oxidizing treatment (FIG. 4D), and Nylon subjected to
hydrolysis treatment (FIG. 4E). The results are shown in FIG. 4. It
can be seen from FIG. 4 that the mass spectrograph of Nylon that
has been immersed in Test Sample-A substantially matches the mass
spectrograph of Nylon that has been force-oxidized in the
atmosphere. Namely it is seen that Nylon that has been immersed in
Test Sample-A is oxidized. FIG. 4B is Nylon that has been immersed
in Test Sample-B, and FIG. 4C is Nylon that has been immersed in
Test Sample-A.
[0035] The surface of each of the above Nylons was machined at an
angle, and infrared spectroscopy was carried out on this cut face
at intervals of about 4 .mu.m in the real depth of the Sample.
These results are shown in FIG. 5. The relative intensity of the
absorption for carbonyl groups generated by oxidation (1710
cm.sup.-1) to the absorption for methylene of Nylon main chains
(2930 cm.sup.-1) is shown on the vertical axis.
[0036] It can be seen from FIG. 5 that the Nylon that has been
immersed in Test Sample-A is oxidized to a depth of 400 .mu.m from
the surface, and that the Nylon that has been immersed in Test
Sample-B is only oxidized to a depth of a few .mu.m from the
surface.
[0037] The cut faces of the Nylon that has been immersed in Test
Sample-A and of the Nylon that has been immersed in Test Sample-B
were analyzed with infrared spectroscopic imaging. The results are
shown in FIG. 6. The relative intensity of the absorption for
carbonyl groups generated by oxidation (1710 cm.sup.-1) to the
absorption for amide bonds of Nylon main chains (1650 cm.sup.-1) is
shown on the vertical axis. It can be seen from FIG. 6 that the
Nylon that has been immersed in the GTL light oil Test Sample-A is
oxidized to a depth of 400 .mu.m from the surface. It can be seen
from the results that there is a high probability that the Nylon
that has been immersed in the GTL light oil of Test Sample-A has
deteriorated as in the manner of the following (1) to (6).
[0038] (1) the low molecular weight paraffins contained in Test
Sample-A permeate into the Nylon.
[0039] (2) accompanying this action, water and oxygen dissolved in
these paraffins also permeate into the Nylon.
[0040] (3) the permeated paraffins oxidize, generating
radicals.
[0041] (4) radicals of the oxidized paraffins react to abstract
hydrogen atoms from within molecules, generating a large number of
radicals. For details of this matter reference can be made to
"Sabrina Carroccio, Concetto Puglisi and Giorgio Montaudo, MALDI
Investigation of the Photooxidation of Nylon-66, Macromolecules
2004, 37, (16), and 6037-6049".
[0042] (5) these radicals oxidize the carbon atoms adjacent to
amide bonds of the Nylon molecules, breaking the molecular
chains.
[0043] (6) hydrogen bonding is reduced between Nylon molecules of
oxidized and reduced molecular weight, and extension is
reduced.
[0044] It can be seen from the above that paraffins having 14 or
fewer carbon atoms within the Samples swell the Nylon, the
paraffins having 14 or fewer carbon atoms oxidize within the Nylon,
and cause oxidation of the Nylon.
Test Example 2
[0045] A model fuel was prepared of the compositions shown in Table
1 below, from reagents of normal paraffin having 7 to 13 carbon
atoms, isoparaffin having 7 to 12 carbon atoms (2-methyl paraffin)
and an isomer of heptane (7 carbon atoms). Note that in Table 1:
"n-C7 to n-C13" indicates normal heptane, normal octane, normal
nonane, normal decane, normal undecane, normal dodecane, and normal
tridecane; "2-Me-C6 to 2-Me-C11" indicates 2-methylhexane,
2-methylheptane, 2-methyloctane, 2-methylnonane, 2-methyldecane,
and 2-methylundecane; and "n-C7 to n-C13 and 2-Me-C6 to 2-Me-C11"
indicates a mixture of both of the above.
[0046] Moreover, .largecircle. indicates that 2 ml of normal
hexadecane has been added, as an internal standard.
TABLE-US-00001 TABLE 1 Details Normal Paraffin having Composition 2
ml of each 16 Carbon Atoms Normal Paraffin n-C7 to n-C13
.largecircle. Isoparaffin 2-Me-C6 to 2-Me-C11 .largecircle. Normal
Paraffin and n-C7 to n-C13 and .largecircle. Isoparaffin 2-Me-C6 to
2-Me-C11
[0047] Nylon was immersed in these model fuels, the model fuels
were analyzed before and after immersion using gas
chromatographic/mass spectrographic methods, and the Nylons were
analyzed before and after immersion using thermal desorption-gas
chromatographic/mass spectrographic methods. The analysis results
of using gas chromatographic/mass spectrographic methods on the
model fuels before and after immersion are shown in FIG. 7.
[0048] The following can be seen from FIG. 7.
(1) isoparaffins are relatively easily oxidized in comparison to
normal paraffin. (2) the amount of alcohols generated from
isoparaffins is about 100 times the amount of alcohol generated
from normal paraffins. (3) the amount of alcohol generated differs
depending on the structure of the isomer. Namely, the ease of
oxidation is different.
[0049] The analysis results of using thermal desorption-gas
chromatographic/mass spectrographic methods on the Nylons before
and after immersion are shown in FIG. 8. It should be noted that
there were no oxidation products detected in the Nylon that has
been immersed in normal paraffin.
[0050] The following can be seen from FIG. 8.
(1) for isoparaffins and for normal paraffins, lower molecular
weight paraffins permeate more readily into Nylon. (2) in a
comparison between a normal paraffin and isoparaffin of the same
number of carbon atoms, it is the isoparaffin that permeates more
readily. (3) alcohols were detected from Nylon that has been
immersed in isoparaffin, but alcohols were not detected from Nylon
that has been immersed in normal paraffin.
[0051] It can be seen from the above that it is important to reduce
paraffins having 14 or fewer carbon atoms in a GTL light oil in
order to suppress swelling of the Nylon, and it is important to
reduce isoparaffins having 14 or fewer carbon atoms in a GTL light
oil in order to lower oxidation and suppress the reduction in
extension of the Nylon.
Examples
[0052] Model fuels (light oils) A to E were produced of Component A
and Component B as below, in blends as shown in Table 2. The
paraffin concentration in the model fuels was 97% by mass or more
in all cases.
[0053] Component A: mixture of equal amounts of normal paraffins
having 8, 10, 12, and 14 carbon atoms.
[0054] Component B: mixture of isoparaffins having 8 and 9 carbon
atoms (2-methylheptane:3-methylheptane:2-methyloctane, at 4:3:3
(volume ratio)).
[0055] Tensile tests were carried out after immersion treatment in
each of the above model fuels of test pieces produced as described
below.
[0056] (1) Test Piece Production:
[0057] Nylon-66 was formed according to JISK7162 (ISO3167) and
manufactured into test pieces.
[0058] (2) Immersion Processing
[0059] 250 ml of model fuel was placed in a 300 ml volume pressure
container (internal diameter:45 mm, internal height: 235 mm), 3
test pieces were immersed therein and heated to 120.degree. C. for
475 hours. Before immersion the test pieces were dried for 4 hours
at 100.degree. C. in a vacuum.
[0060] (3) Tensile Test:
[0061] Tensile testing was carried out on the test pieces after
immersion using a tension testing device (made by Shimadzu:
AG-10kNC) in accordance with ISO527 (the extension velocity was set
at 50 mm/min). The test pieces were stored in a desiccator from
after immersion up until just before tensile testing.
[0062] (4) Results:
[0063] The results of tensile testing are shown in Table 2 below.
Table 2 shows values of the average extensions measured at breakage
of the three test pieces. A plot of the results of Table 2 is shown
in FIG. 9. It can be seen from FIG. 9 that the extension of the
Nylon test pieces falls off rapidly when the concentration of
isoparaffin exceeds 10% by mass.
TABLE-US-00002 TABLE 2 Isoparaffin Concentration Model Fuel in the
Paraffin (%) Extension on Breakage (mm) A 0.0 38.4 B 3.0 35.3 C 7.0
34.2 D 10.0 35.4 E 13.0 22.1
[0064] The entire disclosure of Japanese Patent Application No.
2006-275311 is incorporated by reference herein.
[0065] All publications, patent applications, and technical
standards mentioned in this specification are herein incorporated
by reference to the same extent as if each individual publication,
patent application, or technical standard was specifically and
individually indicated to be incorporated by reference.
* * * * *