WO2008044641A1

WO2008044641A1 - Light oil composition

Info

Publication number: WO2008044641A1
Application number: PCT/JP2007/069584
Authority: WO
Inventors: Hitoshi Hayashi; Tadao Ogawa; Eiichi Sudo; Ayako Ohshima; Keiko Fukumoto; Atsushi Murase
Original assignee: Toyota Jidosha Kabushiki Kaisha
Priority date: 2006-10-06
Filing date: 2007-10-05
Publication date: 2008-04-17
Also published as: JP2008094879A; EP2083061A1; EP2083061A4; US20100012551A1

Abstract

Disclosed is a light oil composition which does not cause any deterioration in a nylon-based material. Specifically disclosed is a light oil composition containing a paraffin at a concentration of 97% by mass or more, wherein the content of an isoparaffin having 14 or less carbon atoms in the paraffin is 10% by mass or less.

Description

Specification

Light oil composition

Technical field

[0001] The present invention relates to a gas oil composition, and more particularly, to a GTL (Gas to Liquid) gas oil composition.

Background art

[0002] Much research on particulate matter (PM) has been made since it was reported that particulate matter (PM) emitted from diesel vehicles was carcinogenic in the 1970s. As measures to reduce PM, the fuel injection pressure has been increased and exhaust aftertreatment systems have been developed for vehicles, and low sulfur has been promoted for diesel oil. Urban diesel oil (Class-1), which has been used in Sweden since 1993, is a typical low-sulfur diesel oil (see Non-Patent Document 1, for example).

[0003] On the other hand, the use of GTL diesel oil has attracted attention from the viewpoint of reducing PM emissions. GTL diesel oil converts natural gas and heavy oil into water gas, obtains synthetic oil by Fischer-Tropsch synthesis (FT synthesis), and fractionates high-boiling fractions in the synthetic oil. This is a fraction corresponding to the boiling range of light oil obtained by hydrocracking, isomerization and the like.

[0004] This GTL diesel oil was produced in Germany during the Second World War, after which production was discontinued. In the late 1980s, the problem of environmental pollution began to be addressed globally, and GTL diesel was once again attracting attention. In 1992, production of GTL diesel oil was started by Mossgas in South Africa. Since 1998, SwRI's Melin da Sirman announced at the SAE international conference that GTL diesel oil has the lowest PM emissions (see Non-Patent Documents 2 and 3, for example). Attention has been focused on and GTL plants have been built around the world.

[0005] GTL diesel oil is currently produced at 100,000 barrels per day worldwide, and 600,000 barrels per day (total consumption of Japanese diesel oil in 2010) when all the plants currently under construction are in operation. It is said that it will be produced! /, Ru (for example, see Non-Patent Document 4).

Non-Patent Document 1: Sweden Class-1: RF Tucker, RJ Stradling, PE Wolve ridge, KJ Rivers and A. Ubbens, The Lubricty of Deeply Hydrogen ated Diesel Fuels— The Swedish Experience, SAE942016

Non-Patent Document 2: Kaoru Kawada, Prospects for Next-Generation Synthetic Fuel Oil (1st) "Quality Trends of Petroleum Products and Issues of Existing Refining Technology", Petrotech, 23, (12) ppl061-1066

Non-Patent Document 3: Jun Fujimoto, Shizukiri Kiryu, Prospects for Next-Generation Synthetic Fuel Oil (3rd) "Technology Development Trends for FT Synthesis", Petrotech, 24, (2) ppl l3-118

Non-Patent Document 4: Yukihiro Tsukazaki, Recent Trends in Automotive GTL Fuel, Automotive Technology, 55, (5), pp. 67-72, (2001)

Disclosure of the invention

Problems to be solved by the invention

[0006] The power that GTL diesel oil is expected to spread steadily in the future The effects of GTL diesel oil on fuel-based materials are hardly clarified. We investigated the effects of GTL diesel on the resins and rubbers used in diesel vehicle fuel systems. As a result of a tensile test with resin and rubber immersed in GTL diesel oil, it was found that the elongation of nylon 66 immersed in general GTL diesel oil was greatly reduced. Until now, nylon has been widely recognized as a material that can withstand hydrocarbons, so the elongation of nylon soaked in GTL gas oil has been greatly reduced, and the phenomenon is completely unexpected.

[0007] Since GTL diesel oil has just been used in the market, there are no reports investigating the effects of GTL diesel oil on fuel system materials. Therefore, the impact of GTL diesel oil on nylon degradation is completely unpredictable! Considering a significant future increase in demand, the development of GTL diesel oil that does not degrade nylon is urgently needed.

[0008] From the above, an object of the present invention is to solve the above problems. That is, an object of the present invention is to provide a light oil composition without deteriorating nylon materials!

Means for solving the problem

[0009] As a result of intensive studies to solve the above problems, the present inventors have conceived the following present invention and found that the problems can be solved. That is, the present invention is a light oil composition characterized in that the concentration of paraffin is 97% by mass or more and the concentration of isoparaffin having 14 or less carbon atoms contained in the paraffin is 10% by mass or less. . The invention's effect

[0010] According to the present invention, it is possible to provide a light oil composition without degrading a nylon-based material!

[0011] FIG. 1 is a graph showing the amount of dissolved oxygen in GTL diesel oil before and after immersion.

FIG. 2 is a graph showing the amount of dissolved oxygen in paraffin before and after immersion.

[FIG. 3] Thermal desorption of nylon [FIG. 3] A graph showing a GC / MS total ion chromatogram. (A) is nylon immersed in sample A, and (B) is nylon immersed in sample B.

[Fig. 4] MALDI-MS mass spectrum of nylon, (A) is nylon that has not been treated, (B) is nylon immersed in Sample-B, (C) Is nylon immersed in Sample A, (D) is oxidized nylon, and (E) is hydrolyzed nylon.

FIG. 5 is a diagram showing the results of nylon depth direction analysis.

FIG. 6 is a diagram showing the results of analysis of the depth direction of nylon by IR imaging. (A) is nylon immersed in sample—A, and (B) is nylon immersed in sample—B.

FIG. 7 is a diagram showing the results of gas chromatography / mass spectrometry analysis of model fuel before and after immersion, (A) shows paraffins and (B) shows oxidation products (alcohol).

[Fig. 8] This figure shows the results of thermal desorption and gas chromatography / mass spectrometry analysis of nylon before and after immersion.

FIG. 9 is a graph showing the relationship between isoparaffin concentration and elongation at break.

BEST MODE FOR CARRYING OUT THE INVENTION

[0012] The light oil composition of the present invention is a GTL light oil or a gas oil composition containing GTL light oil, particularly having a paraffin concentration of 97% by mass or more and having no more than 14 carbon atoms contained in norafine. The concentration of is less than 10% by mass. If the concentration of paraffin is less than 97% by mass, it cannot be said to be a clean fuel due to its PM emission capacity. Biodiesel oil is also acceptable, and degradation of the fuel itself and other materials becomes a problem. In addition, if the concentration of isoparaffin having 14 or less carbon atoms exceeds 10% by mass, the nylon material used in the fuel system oxidizes and depolymerizes to lower molecular weight, or the elongation decreases. material Will deteriorate.

By the way, the presence of isoparaffin has the effect of lowering the cetane number of GTL light oil (lowering the cetane number of normal paraffin too high) and lowering the viscosity. Therefore, when the light oil of the present invention has a high viscosity, it is preferable to adjust the viscosity by adding a highly branched isoparaffin having 15 or more carbon atoms. The content of the highly branched isoparaffin having 15 or more carbon atoms is not particularly limited as long as it has a desired viscosity and cetane number.

[0014] The light oil of the present invention can be produced, for example, as follows. That is, paraffin obtained by FT reaction (Fischer-Tropsch reaction) is hydrocracked on a solid acid catalyst to obtain isoparaffin. Next, this isoparaffin is analyzed by gas chromatography to examine the concentration of isoparaffin having 14 or less carbon atoms. Determine the concentration of isoparaffin having 14 or less carbon atoms analyzed by gas chromatography (consider that the concentration of isoparaffin after mixing is 10% by mass or less), determine the amount of addition, and obtain it by the above FT reaction with isoparaffin. Produced by mixing with the paraffin obtained.

[0015] The light oil of the present invention as described above has the following advantages.

(1) By making the GTL diesel oil into the composition as in the present invention, it can be used in a diesel vehicle without changing the nylon material used in the conventional fuel system.

(2) Also, when the GTL light oil of the present invention is mixed with conventional light oil, it can be used in diesel vehicles without changing the nylon material.

(3) Diesel vehicle exhaust can be cleaned by transferring diesel oil to GTL diesel oil or GTL diesel oil composition.

Example

Hereinafter, the present invention will be specifically described with reference to experimental examples and examples, but the present invention is not limited thereto.

[0017] [Experiment 1]

Two types of GTL diesel oil (simulated sample A and simulated sample B) with different concentrations of low molecular weight (low carbon number) paraffin were prepared. Sample-A was prepared to contain more low-molecular-weight paraffin than Sample-B, and its composition was confirmed by GC.

[0018] Next, the amount of oxygen dissolved in each of the sample-A and the sample-B is determined by molecular sieve. Using a 3 m long column packed with probe 13X, the gas chromatographic method (with thermal conductivity detector) was used. The results are shown in Figure 1. Figure 1 shows that Sample A has more dissolved oxygen than Sample B. This is probably because sample A contains more low-molecular-weight isoparaffin than sample B.

[0019] The amount of dissolved oxygen was measured for normal paraffins and isoparaffins (2 methyl paraffins) having 8 to 12 carbon atoms. The result is shown in Fig.2. The vertical axis in FIG. 2 is the dissolved oxygen concentration at room temperature (same for FIG. 1). Figure 2 shows that (1) isoparaffin contains more oxygen than normal paraffin, and (2) the same type of paraffin contains more oxygen as the carbon number decreases.

[0020] Nylon-66 (hereinafter simply referred to as "nylon") was immersed in each of Sample-A and Sample-B. The surface layer of each nylon after being immersed for 500 hours was cut out, heated in helium at 250 ° C., and the generated gas was analyzed by gas chromatography / mass spectrometry. The result is shown in Fig. 3.

Yes

[0021] From Fig. 3, it was found that nylon immersed in sample A contained (1) more low-molecular-weight paraffin than nylon immersed in sample B. It was also found that (2) the paraffin infiltrated into nylon had a higher proportion of isoparaffin than the original sample.

[0022] Samples collected from the respective nylon surfaces were analyzed by matrix-assisted laser desorption mass spectrometry (MALDI-MS). Nylon without any treatment (Fig. 4 (A)), nylon with oxidation treatment (Fig. 4 (D)), and nylon with hydrolysis treatment (Fig. 4 (E)), respectively. The same analysis was conducted for. The results are shown in Fig. 4. From Fig. 4, it was found that the mass spectrum of nylon immersed in Sample A almost coincided with the mass spectrum of nylon that was forcibly oxidized in the atmosphere. That is, it was found that the nylon immersed in Sample A was oxidized. Fig. 4 (B) shows nylon immersed in Sample 1B, and Fig. 4 (C) shows nylon immersed in Sample A.

[0023] The surface of each of the above nylons was cut obliquely, and the cross-section was made to the actual depth of the sample, and infrared spectroscopic analysis was performed at intervals of about 4111. The results are shown in FIG. The vertical axis shows the intensity ratio between the absorption of carbonyl groups generated by oxidation (171 Ocm " ¹ ) and the absorption derived from methylene in the nylon main chain (2930 cm- ¹ ). [0024] From FIG. 5, nylon immersed in sample A is oxidized to a depth of 400 m from the surface, while nylon immersed in sample B is oxidized only a few meters from the surface. I understood it.

[0025] Cross sections of nylon immersed in sample A and nylon immersed in sample B were analyzed by infrared spectroscopic imaging. The result is shown in FIG. The vertical axis shows the intensity ratio between the absorption of the carbonyl group generated by oxidation (1710 cm— and the absorption derived from the amide bond of the nylon main chain (Ι δ δ π π ¹ ). It can be seen that the nylon immersed in the GTL diesel oil is oxidized from the surface to a depth of 400 m. From these results, the nylon immersed in Sample A is the following (1) to ( It was found that there was a high possibility of deterioration as shown in 6)!

Yes

[0026] (1) Low molecular weight paraffin contained in Sample A enters nylon.

(2) At the same time, it dissolves in norafin! /, And water and oxygen enter the nylon.

(3) The invading paraffin is oxidized to generate radicals.

(4) Radicals oxidized from paraffins generate many more radicals by intramolecular hydrogen abstraction reaction. For details of the contents, see “Sabrina Carroccio, Concerto Puglisi and Giorgio Montaudo, MALDI Investigation of the Photooxidation of Nylon—66, Macromolecules 2004, 37, (16), 6037 6049”.

(5) These radicals oxidize the carbon adjacent to the amide bond of the nylon molecule and break the molecular chain.

(6) The hydrogen bond between the oxidized and low molecular weight nylon molecules decreases, and the elongation decreases.

[0027] From the above, it was found that the paraffin having a carbon number of 14 or less in the sample swells the nylon, oxidizes the isoparaffinic force S having a carbon number of 14 or less, and oxidizes inside the nylon, thereby oxidizing the nylon.

[0028] [Experiment 2]

A model fuel having the composition shown in Table 1 below was prepared using a normal paraffin having 7 to 13 carbon atoms, isoparaffin having 7 to 12 carbon atoms (2 methyl paraffin) and heptane isomers (7 carbon atoms). In Table 1, “n—C7 ~! 1C13” means normal heptane, no Represents normal octane, normal nonane, normal decane, normal decane, normal dodecane, and normal tridecane. , 2-Methyloctane, 2-Methylnonane, 2-Methyldecane, 2-Methylundecane, "N-C7 ~! 1 C13 and 2-Me-C6-2-2-Me-C1 1" Represents a mixture. “◯” indicates that 2 ml of normal hexadecane was obtained as an internal standard.

[0029] [Table 1]

[0030] Then, nylon is immersed in these model fuels, and the model fuels before and after immersion are gas chromatographed.

/ Nylon before and after immersion was analyzed by thermal desorption and gas chromatography Z mass spectrometry by mass spectrometry. Figure 7 shows the results of gas chromatographic / mass spectrometry analysis of the model fuel before and after immersion.

[0031] From Fig. 7, the following was found.

(1) Isoparaffins are more easily oxidized than normal paraffins.

(2) The amount of alcohol produced from isoparaffin is about 100 times the amount of alcohol produced from normal paraffin.

(3) The amount of alcohol produced varies depending on the structure of the isomer. In other words, the ease of oxidation is different.

[0032] FIG. 8 shows the results of analyzing the nylon before and after immersion by thermal desorption / gas chromatography / mass spectrometry. At this time, no oxidation product was detected from nylon immersed in normal paraffin.

[0033] From Fig. 8, the following was found.

(1) For both paraffins and normal paraffins, the lower molecular weight paraffin Easy to penetrate.

(2) When normal paraffin and isoparaffin with the same carbon number are compared, isoparaffin is easier to penetrate.

(3) Force that alcohol can be recognized from nylon immersed in isoparaffin No alcohol is detected in nylon immersed in normal paraffin.

[0034] As described above, in order to suppress the swelling of nylon, from GTL diesel oil, to reduce the number of paraffins having 14 or less carbon atoms, and to suppress the reduction of nylon oxidation and elongation, from GTL diesel oil, It was found that it is important to reduce the number of isoparaffins with 14 or less carbon atoms.

[0035] [Example]

Model fuels (light oils) A to E were prepared with the following components A and B blended as shown in Table 2 below. The concentration of paraffin in any model fuel is 97% by mass or more.

[0036] Component A: Equal mixture of normal paraffins having 8, 10, 12, 14 carbon atoms

Component B: Mixture of isoparaffins having 8 and 9 carbon atoms (2-methylheptane: 3-methylheptane: 2-methyloctane 4: 3: 3 (volume ratio))

[0037] After each of the above model fuels! /, After immersing the prepared test piece as follows:

A tensile test was performed.

[0038] (1) Preparation of test piece:

Nylon-66 was molded according to JISK7162 (IS 03167) to produce a test piece.

[0039] (2) Immersion treatment:

A model container of 25 Oml was placed in a pressurized container (inner diameter: 45 mm, inner height: 235 mm) having an internal volume of 300 ml, and three test pieces were immersed therein and heated at 120 ° C. for 475 hours. The specimens were dried for 4 hours at 100 ° C under vacuum prior to immersion.

[0040] (3) Tensile test:

The test piece after immersion was subjected to a tensile test according to IS0527 (however, tensile speed: 50 mm / min) using a tensile test device (AG-lOkNC manufactured by Shimadzu Corporation). The specimen after immersion was stored in a desiccator until immediately before the tensile test.

[0041] (4) Results: The results of the tensile test are shown in Table 2 below. Table 2 shows the average elongation at break measured by three test pieces. A plot of the results in Table 2 is shown in Figure 9. From Fig. 9, it was found that the elongation of the nylon specimen decreases rapidly when the concentration of isobarafine exceeds 10% by mass.

[Table 2]

The entire disclosure of Japanese Patent Application No. 2006-275311, filed in Japan, is incorporated herein by reference.

In addition, all documents, patent applications, and technical standards described in this specification are the same as if each document, patent application, and technical standard were specifically and individually stated to be incorporated by reference. Which is incorporated herein by reference.

Claims

The scope of the claims

[1] A gas oil composition, wherein the concentration of norafin is 97% by mass or more and the concentration of isoparaffin having 14 or less carbon atoms contained in the paraffin is 10% by mass or less.

[2] The light oil composition according to claim 1, comprising a highly branched isoparaffin having 15 or more carbon atoms.