JPH07268366A - Production of light oil reduced in pollution - Google Patents

Abstract

PURPOSE:To obtain light oil reduced in pollution which can reduce the concentrations of NOx and fine soot particles in exhaustion gas simply and very economically by admixing diisopropyl ether and isopropyl alcohol to the light oil. CONSTITUTION:This production method for light oil reduced in pollution comprises: propylene is hydrated, unreacting propylene is separated from the reaction mixture and recycled to the hydration, light oil fraction is admixed to the remaining of the reaction mixture and mixed therewith under stirring and allowed to stand, and the formed aqueous phase is recycled to the hydration and the oil phase is separated and collected as the low pollution light oil.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to nitrogen oxides (NOx).
The present invention relates to an economical production method of low-pollution gas oil in which generation of so-called particulate matter (PM) such as soot, heavy unburned hydrocarbon (SOF), and particulate matter of sulfate is suppressed, and more specifically, By mixing isopropyl alcohol and diisopropyl ether produced by the hydration reaction of propylene with a gas oil fraction and directly extracting the alcohol and ether,
The present invention relates to a method for producing low pollution gas oil simply and economically.

A large amount of NOx and PM are released from exhaust gas from a diesel engine that uses light oil as a fuel, and adverse effects such as air pollution and deterioration of living environment are becoming a problem. There is a strong demand for reduction of substances. The present invention addresses this problem.

[0003]

2. Description of the Related Art When an oxygen-containing organic compound such as ether is added to diesel fuel such as light oil, the combustibility of diesel fuel is improved and the amount of NOx, soot, etc. generated is reduced. No.

Generally, the method for producing isopropyl alcohol is the Weber method (Hydrocar) by indirect hydration using sulfuric acid.
bon Processing, November, Vol.46, No.11), Tokuyama Soda Method (catalyst Vol.18, No.6, 1976), which directly hydrates in a liquid phase homogeneous system using heteropolyacid, sulfonic acid cation exchange The German Texaco method (JP-A-49-126607) in which a resin is directly hydrated in a gas-liquid mixed phase system has already been industrialized.

Further, a method for producing diisopropyl ether is a synthetic method by direct hydration of propylene and water (Japanese Patent Laid-Open No. 1-58242).
No. 246233), a synthesis method from propylene and isopropyl alcohol (JP-A No. 52-131508), and the like are known.

As disclosed in the above-mentioned JP-A-58-74789, in the known method, a method is used in which the oxygen-containing organic compound to be used is separated and purified by distillation or the like, and then added to gas oil. Up to now, no method has been reported for obtaining low-pollution gas oil by using propylene as a raw material and directly mixing the hydration reaction product with gas oil.

In each of the above alcohol and ether production methods, when isopropyl alcohol and diisopropyl ether are efficiently separated from a mixed solution of water, isopropyl alcohol and diisopropyl ether by distillation, the water azeotrope mixture and the separation process are complicated. Becomes a problem, and it is difficult to reduce the cost.

Further, in the method of extracting and separating the target substance with a solvent, although the recovery efficiency is high, distillation purification is indispensable for recovering the extraction solvent, and the process becomes complicated. In any case, the cost increase due to the utility associated with the distillation operation cannot be avoided.

[0009]

DISCLOSURE OF THE INVENTION According to the present invention, a low-pollution gas oil capable of reducing the concentrations of NOx and PM in exhaust gas can be produced simply and extremely economically by incorporating diisopropyl ether and isopropyl alcohol into the gas oil. It provides a method.

[0010]

DISCLOSURE OF THE INVENTION The inventors of the present invention have proposed that a reaction product containing water, isopropyl alcohol and diisopropyl ether after removing unreacted propylene from a reaction product produced by a hydration reaction of propylene is treated with a gas oil distillate. It is possible to reduce NOx and PM in the exhaust gas at low cost without distillation by directly blending with the components and extracting and separating isopropyl alcohol and diisopropyl ether into an oil phase consisting of a gas oil fraction. The inventors have found that low-pollution diesel oil can be produced and completed the present invention.

That is, the gist of the first invention is that a gas oil fraction is added to the product obtained by the hydration reaction of propylene, and the mixture is stirred, mixed, and allowed to stand, and the resulting oil phase is separated and recovered. And a second invention is to separate unreacted propylene from a reaction product obtained by a propylene hydration reaction step, and separate the separated propylene from the hydration reaction step. Gas oil fraction was added to the rest of the reaction product, and the mixture was stirred, mixed and allowed to stand, the resulting aqueous phase was recycled to the hydration reaction step, and the oil phase was separated as low pollution gas oil. , A method for producing low-pollution diesel fuel, which comprises recovering.

The method of the present invention will be described in detail below. The direct hydration reaction of propylene can be applied by any known method, and may be either a batch method or a continuous method, but a fixed bed flow continuous method is industrially preferable.

Usually, propylene used for the hydration reaction may be produced by any method, but it is generally produced by a fluid catalytic cracking unit, a catalytic reforming unit or an ethylene plant, and a small amount of propane or the like. The impurities may be included. That is, it is desirable that the purity of propylene is high, but if the content of impurities is 10% by weight or less, it is acceptable, and if possible, 3% by weight or less is preferable. The method of the present invention is a method for producing low-pollution diesel oil, and diisopropyl ether and isopropyl alcohol are added for the purpose of reducing NOx and PM in exhaust gas, and the purity does not cause any particular problem. Even if a small amount of other olefin such as butylene is mixed, there is no particular problem.

As the catalyst used for the hydration reaction, heteropolyacid, phosphoric acid-supporting diatomaceous earth, acidic ion exchange resin, zeolite, typically zeolite β, ZSM-5, styrene type cation exchange resin and the like are used. The reaction varies depending on the catalyst used, but generally the reaction temperature is 50 to 300.
℃, preferably 100-140 ℃, reaction pressure 10-15
0 kg / cm ^2, preferably 40~90kg / cm ^2, L
HSV 0.01 to 20 h ^-1 , preferably 0.1 to 5 h ^-1
It is performed under the conditions of. The reaction is generally carried out in a gas-liquid mixed phase.

The reaction product obtained from the hydration reaction step is
Unreacted propylene is separated by lowering the pressure, and the separated propylene is recycled to the hydration reaction step. The reaction product obtained by separating the unreacted propylene consists of water, isopropyl alcohol, diisopropyl ether and a small amount of propylene polymerized oil, but these are, as they are, the aqueous phase mainly composed of isopropyl alcohol-water and the isopropyl alcohol-diisopropyl ether-polymerized oil. It can be separated into two main oil phases. However, in the method of the present invention, these are not separated into two phases but are directly mixed with the gas oil fraction for extraction. Isopropyl alcohol is soluble in water and also in diisopropyl ether, the quantitative proportions of the two phases obtained here and their composition depend on the equilibrium, at which stage the aqueous phase contains a considerable amount of isopropyl alcohol. Like diisopropyl ether, isopropyl alcohol has the effect of reducing NOx and PM in exhaust gas, so it may be returned to the hydration reaction step to increase the yield of diisopropyl ether, but it can be extracted directly into gas oil. Is also good. By not mixing into two phases at this stage and mixing them together with the gas oil fraction at once, it is not necessary to carry out the operations such as distillation separation, which was conventionally necessary, and distillation for recovering the solvent after extraction with benzene, xylene, etc. Instead, it is possible to extract most of the isopropyl alcohol produced in the hydration reaction step into the gas oil fraction. However, since isopropyl alcohol is less effective than diisopropyl ether, it is preferable to lower the selectivity of isopropyl alcohol in the hydration reaction.

A light oil fraction, specifically, for example, a distillation property 150, is added to the reaction mixture obtained by removing the unreacted propylene.
Reaction product after removal of propylene using one or more gas oil fractions selected from light oil fraction at 370 ° C., straight-run gas oil, desulfurized gas oil, light circulating oil (LCO) of FCC, etc. An oily phase containing essentially all of the diisopropyl ether contained in the reaction product as well as most of the isopropyl alcohol is separated from. The extraction can be carried out batchwise or continuously, but industrially it is preferable to carry out extraction. The extraction conditions are not particularly limited, but the extraction temperature is 15 to 200 ° C., preferably 20 to 100.
C., the extraction pressure is preferably atmospheric pressure to 50 kg / cm < ² >, preferably atmospheric pressure to 20 kg / cm < ² >. Also,
Extraction was carried out with a gas oil fraction of 0.1 to 10 per volume of the reaction product.
It is preferable to use 0 parts by volume, preferably 0.5 to 20 parts by volume. If the ratio of light oil fractions is too large, it is necessary to upsize the equipment and the N required for the target product, low-pollution light oil.
The effect of reducing Ox and PM is also insufficient, and if it is too small, it is not preferable in terms of composition as light oil. If the temperature is too high, not only the utility cost will increase, but also pressure will be required to avoid evaporation of alcohol and ether, and the equipment cost will increase, and if it is too low, the viscosity of gas oil will increase and separation from the water phase will occur. It worsens, and in some cases unreacted water solidifies. Further, if the pressure is too high, the pressure resistance of the device must be increased, which is disadvantageous because the cost is increased.
From the above, extraction is preferably performed under the above conditions.

The obtained extraction mixed liquid is separated in a separation tank into a light oil phase (oil phase) and an aqueous phase mainly composed of isopropyl alcohol-water, and the latter is recycled to the hydration reaction step.

For extraction, a method of introducing the above-mentioned light oil fraction directly into the reaction product line from the hydration reaction step and separating it from the aqueous phase in a separation tank is simple and easy. At that time, the light oil may be simply supplied at a speed that causes a turbulent flow state in the line, but it is desirable to positively cause the reaction product and the light oil fraction to be mixed by using an orifice, a pump or the like. It is also possible to extract and separate by a countercurrent or a cocurrent method using an extraction tower. Any known extraction column may be used as the extraction column. For example, a packed column such as Raschig ring or a bell saddle, a plate column equipped with a perforated plate or a baffle plate, and the like can be used. In the case of countercurrent extraction, it is not always necessary to install a separation tank after that, but in the case of cocurrent extraction, it is necessary to install a separation tank as in the case of the above line extraction.

The method of the present invention is simply shown by a flow diagram as shown in FIG. As is apparent from FIG. 1, in the method of the present invention, there is no evaporation or distillation step other than the step of recovering unreacted propylene.

[0020]

EXAMPLES The present invention will now be described in more detail by way of examples, which are merely examples and do not limit the present invention.

Example 1 A fixed bed flow reactor was used, using an acidic ion exchange resin [Amberlyst 16 (manufactured by Organo Corporation)], a reaction temperature of 120 ° C., a reaction pressure of 70 kg / cm ² , and propylene / water. ^{1 under} the condition of molar ratio of 4 and LHSV2h ^-1
Hydration reaction was performed for 0 hours. The purity of propylene used is 9
It was 9.9% by weight.

The reaction product components after separation of unreacted propylene were 52.5% by weight of diisopropyl ether, 34.3% by weight of isopropyl alcohol, and other organic products.
It was 3% by weight and 6.9% by weight of water. The conversion rate of raw material propylene was about 14%.

1 part by volume of the reaction product component after separation of the above-mentioned propylene was commercialized as No. 2 diesel oil 4 at 50 ° C. and 5 kg / cm ² .
The ingredients were mixed in a proportion of volume part, well stirred and allowed to stand to separate into an aqueous phase and an oil phase. The oil phase obtained was 98.8% by volume, based on the total amount of treated reaction product components and commercial No. 2 gas oil added, while the proportion of the water phase obtained was 1. It was 2% by volume.

When the composition of the obtained oil phase was analyzed by gas chromatography, the contents of the above components were as follows.

Diisopropyl ether (9.8% by weight), isopropyl alcohol (5.3% by weight), other organic products (1.0% by weight), water (0.0% by weight). It was recycled to the reaction step.

Exhaust gas characteristics of a diesel engine using the oil phase obtained under the above conditions as a fuel were comparatively evaluated with a commercially available No. 2 diesel oil as a reference.

Table 1 shows the general properties of the commercial No. 2 gas oil used as the reference fuel and the oil phase obtained from the extraction process.

[0028]

[Table 1]

Table 2 shows the specifications of the diesel engine used for the evaluation.

[0030]

[Table 2]

It is known that in this type of evaluation, the measurement results vary depending on the test conditions. In this evaluation, the temperature of the room where the engine is installed is 20 to 25 ° C.
The engine intake air temperature was controlled at 25 ° C and the humidity was controlled at 50%.

The operating conditions of the engine are in accordance with the diesel vehicle 13 mode shown in FIG. 2, and the operating pattern is shown in FIG.
As shown in.

The exhaust gas was analyzed using a diversion tunnel, and the fuel consumption rate at this time was also measured.

The evaluation results are shown in Tables 3 and 4. This result is obtained by deleting the measurement results of the first and the cycle with the largest fluctuation among the five operation cycles and showing the measurement results of the remaining three times.

[0035]

[Table 3]

[0036]

[Table 4]

From these results, the oil phase obtained from the extraction process has a 4.8% reduction in NOx and a 8.2% reduction in particulate matter (PM) compared to the standard emission amount of light oil. However, there was no significant difference in the emission of carbon monoxide and unburned gaseous hydrocarbons between the two.

[0038]

According to the method of the present invention, the reaction product components obtained by simply removing the unreacted propylene from the hydration reaction product of propylene are mixed with the gas oil fraction, and the separated aqueous phase is removed. A low-pollution gas oil can be obtained easily, simply and economically without the need for operations such as distillation.

[Brief description of drawings]

FIG. 1 is a flow sheet illustrating the outline of the steps of the method of the present invention.

FIG. 2 is a graph showing D-13 mode operating conditions used in Example 1.

FIG. 3 is a graph showing an operation pattern performed at the time of sampling in Example 1.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masaura Miura 1134-2, Gongendo, Satte City, Saitama Prefecture, inside the Research and Development Center, Cosmo Research Institute Co., Ltd. (72) Haruo Takizawa, 1134, Gongendo, Satte City, Saitama Prefecture 2 Cosmo Research Institute Co., Ltd. Research and Development Center

Claims (2)

[Claims] 1. A process for producing a low-pollution gas oil, which comprises adding a gas oil fraction to a product obtained by a hydration reaction of propylene, stirring and mixing the mixture, and then leaving it to stand, and separating and recovering the resulting oil phase. 2. Unreacted propylene is separated from the reaction product obtained by the propylene hydration reaction step, and the separated propylene is recycled to the hydration reaction step, leaving a gas oil fraction as the residue of the reaction product. In addition, stir, mix, and leave still,
A method for producing a low-pollution gas oil, which comprises recycling the produced water phase to the hydration reaction step, and separating and recovering the oil phase as a low-pollution gas oil.