JPH0354295A - Purification of light hydrocarbon and adsorbent for purification of light hydrocarbon - Google Patents

Abstract

PURPOSE:To remove efficiently nitrogen compd. and oxygen compd. from a light hydrocarbon by using a silica/alumina carrying a rare earth metal as an absorbent. CONSTITUTION:A light hydrocarbon obtd. by cracking a petroleum or coal heavy oil, especially a 4-10C paraffin, olefin, etc., is brought into contact with an adsorbent consisting of an amorphous silica/alumina (the alumina content is pref. 10-50 wt.%) carrying 0.1-5.5 wt.%, pref. 0.1-2.0 wt.% rare earth metal (e.g. Ce, La, Y, etc.) (at ordinary temp. and usually at 10 kg/cm<2> or lower) to absorb and remove nitrogen compd. (e.g. amines, pyridines, nitriles, etc.) and/or oxygen compd. (e.g. phenols and others) contained in the hydrocarbon.

Description

[Detailed description of the invention]

stomach. OBJECTS OF THE INVENTION The present invention relates to a method for adsorbing and removing nitrogen compounds and oxygen compounds contained as impurities in light hydrocarbons, and an adsorbent for the same. Carbon number 4 obtained by cracking light hydrocarbons, especially heavy oil
The light fraction in the range of ~10 contains 10 to 1000 ppm by weight of nitrogen compounds and oxygen compounds as impurities, but these impurities are used when light hydrocarbons are used as gasoline, solvents, raw materials for chemicals, etc. In some cases, various problems arise. One of the major problems is that these light hydrocarbons act as catalyst poisons for the catalysts that process them, and effective pretreatment techniques are long-awaited. E&TSU fl) Hydrorefining method Hydrorefining is a common method for refining hydrocarbons, but the cracked light fraction contains 20 to 50% of olefins that can be used effectively. This is not preferable since these are hydrogenated at the same time during hydrorefining. (2) Adsorption method Because it was thought that basic nitrogen compounds such as pyridine were contained in these light hydrocarbons and were particularly harmful to catalysts, titanium oxide and/or silica (Japanese Patent Laid-Open No. 60-1989) -401.95). Shinoka alumina,
Acidic adsorbents such as alumina have been proposed. In addition, for the purpose of further increasing the affinity with basic nitrogen compounds,
Silica, zeolite X. An adsorbent in which anhydrous acidic gas is adsorbed on Y, alumina, silica alumina, etc.
7103) etc. were proposed. However, the nitrogen compounds contained in light hydrocarbons include basic ones such as amines and pyridines, and non-basic ones such as nitriles such as benzonitrile and alkylvirols, and oxygen Since the adsorbent contains acidic or neutral compounds such as phenols, cresols, and ethers, it is not possible to select an adsorbent based only on acid and base considerations. Therefore, in order to adsorb both acidic and basic substances, an amphoteric substance that is neither an acid nor a base is required. Regarding oxygen compounds, silica gel (Japanese Patent Publication No. 55-44049) has been proposed for removing ethers. Furthermore, in Japanese Patent Application No. 63-49471, surface areas of 100 to 800
A method has been proposed in which nitrogen compounds and oxygen compounds are simultaneously adsorbed and removed using silica gel with an average pore size of 10 to 150 m"/g, but although silica gel has excellent adsorption performance, it has poor regeneration properties. Repeated use will significantly degrade performance.The present invention aims to adsorb and remove nitrogen compounds and oxygen compounds, which are excellent in terms of both adsorption performance and regeneration, and to reduce It is an object of the present invention to provide a method for refining hydrocarbons. It is characterized in that it adsorbs and removes nitrogen compounds and/or oxygen compounds contained in hydrocarbons by contacting with an adsorbent made of silica alumina supported by weight%. Alternatively, it is a light hydrocarbon containing an oxygen compound, particularly a hydrocarbon such as paraffin or olefin having a carbon number of 4 to 10, and may be a single component or a mixture of two or more types of hydrocarbons.Adsorption Examples of nitrogen compounds and oxygen compounds to be removed include the various ones listed above, especially nitrogen compounds and oxygen compounds contained in light distillates obtained by cracking petroleum-based and coal-based heavy oils. The base of the adsorbent of the present invention is non-quality Zirica alumina, and it is necessary that it has a pore size sufficient to adsorb the above-mentioned substances to be adsorbed. It is preferable that the alumina content in the silica alumina is 10 to 50% by weight.The amount of rare earth metal supported on the silica alumina is 0.1 to 50% by weight.
The amount is 5.5% by weight, preferably 0.1 to 2.0% by weight. As is clear from Example 1 and FIG. 1 below, especially when the amount of rare earth metal supported is 0.1% by weight,
After exceeding 5.5% by weight, no improvement in adsorption performance is observed. That is, the amount of rare earth metal supported is 0.1 to 5.
．． The effect of improving adsorption performance and regeneration performance is observed only when the content is within the range of 5% by weight. Rare earth metals include cerium, lanthanum, yttrium, etc., but they do not need to be pure metals, and mixed rare earth metals that are easily available on the market may be used. Although the contact between the adsorbent and the hydrocarbon can be carried out batchwise by adding the adsorbent to the hydrocarbon, it is preferable to continuously treat the hydrocarbon by sending the hydrocarbon to a tower filled with the adsorbent. When used by filling a tower with adsorbent, the shape of the adsorbent may be spherical, extruded, tablet, etc., but 1 mm
As mentioned above, it is desirable to have a size of preferably about 1 to 5 mm. Furthermore, a plurality of columns, for example two columns, filled with adsorbent may be provided to perform adsorption and regeneration alternately. The adsorption conditions may be room temperature and the pressure may be selected appropriately, preferably within a range that is not subject to high pressure regulations. Usually 10k
The regeneration conditions are a temperature of 400 to 600°C and a pressure of any value, but usually the adsorbed material is burned while flowing an oxygen-containing gas in the range of normal pressure to 10 kg/cm. The present invention will be explained in detail below using Examples, but the present invention is not limited to these Examples. [Example 1] Silica alumina (1,
A predetermined amount of a commercially available mixed rare earth reagent (mainly cerium and lanthanum) dissolved in water was impregnated into a 8-3 mm extrusion molded product, dried, and calcined at 500°C in air to obtain the composition shown in Table 1. of adsorbent was obtained. As a hydrocarbon raw material, a heavy oil pyrolysis light fraction (hydrocarbon having 4 to 10 carbon atoms) having the following properties was used. Specific gravity (1 5/4℃): 0.705 total N min
= 33 ppm by weight Total S content: 310 ppm by weight Phenol content 2670 ppm by weight Olefin content: 31 ppm by weight Distillation properties IBP:
33℃ EP: 1 6 1. 'C A stainless steel reactor with an inner diameter of 16.1 mm was filled with 40 ml of the adsorbent shown in Table 1, and after drying in a nitrogen stream at 200°C for 3 hours, the raw material was mixed into 80 ml. /hr and distributed through upflow. Adsorption conditions are 5kg/cm”G,
Room temperature, LHSV2. Ohr-'. Analyze the N content of the refined oil at the outlet and find that the N content in the oil is 0 pp by weight.
The amount of oil processed per 1 mβ of adsorbent was determined. The results are shown in Table 1 and Figure 1. (Margins below) 1 Table 1 shows the loading rate (wt%) of rare earth metals on silica alumina [shown on the horizontal axis] and the N content in hydrocarbon oil (O weight %).
Oil processing amount per lm12 of adsorbent (mβ)

[Examples 2 to 5 and Comparative Examples 1 to 4]

Repeated adsorption and regeneration tests were conducted. An adsorbent saturated with adsorption in the same manner as in Example 1 was heated for 40 hours while flowing Nt gas.
The temperature was raised to 0°C (4°C), and then air was introduced to gradually raise the temperature and regenerate. The regeneration conditions are normal pressure. 500'C, GHSV7
It was set as 5hr-'. Thereafter, the adsorbent was cooled and its adsorption performance was examined again in the same manner as in Example 1. After repeating the first (initial) adsorption and regeneration, the second, third, and first
Table 2 shows the measurement results of the adsorption performance at the 0th time. (Leaving space below) Table 2 Adsorbents carrying 0.5 to 2.0% by weight of rare earth gold 11f (RE) have better adsorption performance and regeneration properties than those without it or those carrying 8.0% by weight. It can be seen that it is superior in terms of [Example 6] An adsorbent (RE of 0.5
28 wt% An20. Filled with 800 ml of silica alumina containing silica alumina, and heated at room temperature and pressure, LHSV2. O
The raw material was treated with hr-'. Air regeneration was performed when the adsorbent was saturated, and adsorption regeneration was repeated. Table 3 shows the analysis values for N and O at the first and tenth times. Table 3 shows that the adsorbent of the present invention does not change its adsorption performance for N and O (phenol) even after repeated adsorption and regeneration. [Reference experiment 1? The alumina (Aj2■O,) content in the silica anolemina, which is the base of the landing l1, and the N content in the hydrocarbon oil are 0 weight 1
The relationship between the amount of oil processed (mff) per mε of adsorbent and the amount of ppm obtained was determined in accordance with Example 1, and the results are shown in FIG. In Figure 2, the horizontal axis is the alumina content (wt%) in silica alumina, and the vertical axis is the N content in the hydrocarbon oil (ppm by weight).
This shows the oil treatment crushing (mC) per 1 mff of suction cutting. The lower the alumina content and the higher the silica content, the larger the surface area and the better the adsorption performance. The usable range is alumina content of 10 to 50% by weight. [Effects of the Invention] Since the adsorbent of the present invention is excellent in adsorption performance and regeneration performance, nitrogen compounds and oxygen compounds can be efficiently removed from light hydrocarbons.

[Brief explanation of drawings]

Figure 1 shows the loading rate (wt%) of rare earth metals on silica alumina [shown on the horizontal axis] and the amount of oil processed per 1 mg of adsorbent (mI2) where the N content in the hydrocarbon oil becomes O ppm by weight. [
Figure 2 shows the alumina content (wt%) in silica alumina, which is the base of the adsorbent.
[shown on the horizontal axis] and the oil throughput (mn) per 1 m2 of suction/cutting where the N content in the hydrocarbon oil becomes O ppm by weight [shown on the vertical axis].

Claims (1)

[Claims] 1. Light hydrocarbons are brought into contact with an adsorbent made of silica alumina carrying 0.1 to 5.5% by weight of rare earth metals to remove nitrogen compounds and/or A light hydrocarbon purification method characterized by adsorption and removal of oxygen compounds. 2. The method for refining light hydrocarbons according to claim 1, wherein the light hydrocarbons are light fractions obtained by cracking heavy oil. 3. An adsorbent for refining light hydrocarbons, characterized by being made of silica alumina carrying 0.1 to 5.5% by weight of rare earth metals. 4. The adsorbent for light hydrocarbon purification according to claim 3, wherein the alumina content in the silica alumina is 10 to 50% by weight.