JP2013057075A - Lowering process of total acid number (tan) of liquid hydrocarbon quality feedstock - Google Patents

Abstract

PROBLEM TO BE SOLVED: To selectively lower the total acid number of feedstocks such as a crude oil by hydrogenation.SOLUTION: A lowering process of a total acid number (TAN) of a liquid hydrocarbon quality feedstock is characterized as follows. The liquid hydrocarbon quality feedstock is made to contact with a catalyst that includes a metal oxide of the column third or fourth group of the Periodic Table of Elements or that of a lanthanide oxide, but does not essentially include a metal or a compound thereof of the fifth to tenth group under the existence of a hydrogen-containing gas at the temperature range of 200-400°C and at high pressure, whereby a liquid hydrocarbon quality product having a low total acid number is obtained.

Description

The present invention relates to a method for reducing the total acid number (TAN) of liquid hydrocarbonaceous feedstocks, particularly crude oil.

Background of the Invention Crude oil and other liquid hydrocarbonaceous streams containing large amounts of acid are difficult to refine. Especially in crude oil refinery distillation units, large amounts of acid cause corrosion problems. It is known that acids are removed from liquid hydrocarbonaceous feedstocks by hydrotreating, that is, hydrotreating methods that remove other heteroatoms such as sulfur and nitrogen. However, hydrotreating is a method that takes place downstream of the distillation unit in a refinery.

  In order to avoid the corrosion problems caused by the acid content in crude oil, different crude oil streams are generally blended to obtain crude oil containing an acceptable amount of acid.

  The acid content of crude oil or other hydrocarbonaceous liquids is generally expressed as the total acid number (TAN) of such liquids. TAN represents KOH mg / g liquid required to neutralize the acid according to the method described in ASTM D664.

  There is a need in the art for a method that can minimally convert sulfur-containing compounds, nitrogen-containing compounds, and unsaturated hydrocarbons to reduce the TAN of liquid hydrocarbonaceous streams such as crude oil used in refineries. By such a method, an acceptable refinery feedstock is obtained with minimal hydrogen consumption.

SUMMARY OF THE INVENTION Catalysts that are essentially free of hydrocomponents typically used in hydroconversion reactions, such as hydrodesulfurization, hydrodenitrogenation, and hydrocracking, ie, any of columns 5-10 of the periodic table It has been found that one metal compound can be used to selectively hydrogenate liquid hydrocarbonaceous streams, particularly acids in crude oil.

  Accordingly, the present invention oxidizes a liquid hydrocarbonaceous feedstock in the presence of a hydrogen-containing gas at a temperature in the range of 200-400 ° C. and a high pressure, the oxide or lanthanide metal oxide in the third or fourth column of the periodic table of elements. A liquid hydrocarbonaceous product having a low total acid number (TAN) by contacting with a catalyst containing a product, but essentially free of a metal in columns 5 to 10 or a compound thereof. A method for reducing the total acid number of a hydrogenous feedstock is provided.

  An advantage of the present invention is that other hydrogenation reactions such as hydrodesulfurization, hydrodenitrogenation and saturation of unsaturated hydrocarbons are minimized while reducing the total acid number of the feedstock by hydrogenation.

DETAILED DESCRIPTION OF THE INVENTION In the process of the present invention, the liquid hydrocarbonaceous feedstock is a metal oxide in the third or fourth column of the periodic table of elements at a temperature and pressure in the range of 200-400 ° C. in the presence of a hydrogen-containing gas. The catalyst is contacted with a catalyst comprising an oxide of lanthanide, but essentially free of the metals in columns 5-10 or compounds thereof.

  The feed may be any liquid hydrocarbonaceous stream containing carboxylic acid, i.e. organic acid. The process is particularly suitable for feedstocks containing naphthenic acid. The feedstock is preferably a feedstock comprising preferably a distillation stream such as crude oil, naphtha or gas oil, an atmospheric distillation residual fraction of crude oil, or a hydrocarbonaceous distillation product that does not conform to TAN product standards, such as heating oil. Is preferred. The method of the present invention is particularly suitable for reducing the total acid value of crude oil.

  The hydrogen-containing gas is preferably hydrogen or synthesis gas. The use of synthesis gas as the hydrogen-containing gas is particularly advantageous in remote locations such as offshore oil platforms in situations where hydrogen-containing gas is not available.

  The temperature and pressure for contact with the feedstock catalyst is such that carboxylic acid hydrogenation occurs, ie 200 ° C. or higher. This temperature is lower than the temperature at which thermal decomposition of the carboxylic acid occurs, i.e. below 400 ° C. This temperature is preferably in the range of 250 to 390 ° C, more preferably 300 to 380 ° C.

  The method is performed at high pressure, i.e. higher than atmospheric pressure. This pressure is preferably in the range of 2 to 200 bar gauge pressure, more preferably 10 to 150 bar gauge pressure, even more preferably 25 to 120 bar gauge pressure.

  The catalyst contains a metal oxide or a lanthanide oxide in the third or fourth column of the periodic table of elements (according to recent IUPAC notice). The metal oxide may be a mixed oxide of two or more of these metals. The catalyst is essentially free of metals or compounds thereof in columns 5-10 of the periodic table. Here, this specific compound is essentially free of the minimum possible contamination or residue that may be present in the ore refining of the oxide of column 3 or column 4 or the oxide of lanthanide. Except in amounts, usually in the ppm range or lower, refers to catalysts that do not contain these compounds.

  The catalyst preferably contains column 4 metal oxides or lanthanide oxides. Preferred Group 4 metal oxides are titanium oxide and zirconium oxide, and preferred lanthanide oxide is ceria. Further preferred catalysts consist of titanium oxide and / or zirconium oxide, even more preferably zirconium oxide.

The catalyst can be produced by any production method known in the art. Preferably the catalyst is produced with a specific surface area of at least 10 m ² / g, more preferably at least 30 m ² / g.
The total acid number of the feed used in the process of the present invention is 0.2 mg KOH or more, preferably 0.5 mg KOH or more, and even more preferably 1.0 mg KOH or more per feed.
Here, the total acid value is the amount of KOH (mg) per gram of feedstock as measured by ASTM D664.

The TAN of the liquid hydrocarbonaceous product is preferably 0.2 mgKOH or less, more preferably 0.1 mgKOH or less, and even more preferably 0.5 mgKOH or less per gram of feedstock.
The TAN of the liquid hydrocarbonaceous product having a low total acid value is lowered to such an extent that it is preferably 50% or less, more preferably 30% or less, relative to the TAN of the feedstock.

Hydrogenation method Crude oil in a micro-flow reactor in the presence of hydrogen-containing gas or nitrogen, solid inert material (0.1 mm silicon carbide particles) or one of the catalysts described below (catalyst particles diluted with silicon carbide particles) For at least 100 hours. Various crude oils were used. Experiments 1-8 and 13-16 used West African crude oil (crude oil 1), and Experiments 9-12 used Middle East crude oil (crude oil 2). The specifications for both crude oils are shown in Table 1. The exact conditions for each experiment are shown in Table 2.

  The total acid number (TAN) of the liquid effluent of each experiment was measured by ASTM D664. The concentration of hydrogen sulfide in the vapor phase effluent was measured by gas chromatography. The TAN of the liquid effluent and the hydrogen sulfide concentration in the vapor phase effluent are also shown in Table 2.

  Experiments 3, 4, 6, 7, 9, 10, 12, and 14-16 are experiments according to the present invention. Experiments 1, 2, 5, 8, 11, and 13 are comparative experiments.

Catalysts The following catalysts were used in the hydrogenation experiments.
Titania catalyst 1
A titania catalyst (further referred to as titania 1) was produced as follows. An amount of 3192 g of titania powder (from P25, Degussa; loss on combustion: 4.4 wt% at 540 ° C.) was mixed with 100 g of oxalic acid dihydrate in a mixing mill kneader (Simpson). After 4 minutes of mixing and milling, 981 g of deionized water and 100 g of polyethylene glycol were added and mixing and milling was continued for another 12 minutes. Next, 100 g of methylcellulose was added and mixing and grinding continued for another 20 minutes. The mixture thus formed was shaped by extrusion through a trilobal die plate having a diameter of 1.7 mm. The trilobal body was dried at 120 ° C. for 2 hours and then calcined at 500 ° C. for 2 hours.

The surface area of the obtained titania trilobule was 52 m ² / g as measured by the nitrogen adsorption method (BET method), and the pore volume was 0.31 ml / g as measured by the mercury intrusion method.

Titania catalyst 2
Commercially available X096 (from CRI Catalyst Company) titania particles were used as the titania catalyst (also referred to as titania 2). The surface area of the titania particles was 120 m ² / g as measured by the nitrogen adsorption method (BET method), and the pore volume was 0.32 ml / g as measured by the mercury intrusion method.

Zirconia Catalyst A zirconia catalyst was produced as follows. An amount of 264 g of zirconia powder (from RC100, Daiichi; loss on combustion: 5.3 wt% at 540 ° C.) was mixed with 90 g of a 5 wt% deionized aqueous solution of polyvinyl alcohol in a kneader (Werner & Pfeider Sigma kneader type LUK0.75). . After kneading for 7 minutes, cationic polyacrylamide (from Superfloc, Cytec) was added, and after kneading for 20 minutes, 8 g of deionized water was added. This mixture was kneaded for an additional 22 minutes. The mixture thus formed was shaped into a trilobal body having a diameter of 1.7 mm by extrusion. The extrudate was dried at 120 ° C. for 2 hours and then calcined at 550 ° C. for 2 hours.

The surface area of the obtained zirconia trilobal body was 54 m ² / g as measured by the nitrogen adsorption method (BET method), and the pore volume was 0.35 ml / g as measured by the mercury intrusion method.

Alumina-supported NiMo
A commercially available CRITERION RM-5030, a conventional hydrodesulfurization catalyst (from Criterion Catalyst Company), carrying Ni and Mo on alumina was used.

a) WHV: speed per hour of weight, ie kg oil / kg catalyst / hour. In Experiments 1 and 2, there was no catalyst and a comparable WHV could not be defined (the rate of oil weight per hour was 1.1 kg / kg SiC / hour in Experiments 1 and 2).
b) Gas velocity: standard liter gas per kg oil e) TAN: KOHmg per kg oil
d) Not measured: The liquid effluent had no hydrogen sulfide odor.
e) Not measured: The liquid effluent had a hydrogen sulfide odor.
f) Syngas composition: hydrogen 33.2 vol%, CO20.7 vol%, balance nitrogen

Claims (10)

  The liquid hydrocarbonaceous feedstock contains a metal oxide or a lanthanide oxide in the third or fourth column of the periodic table of elements at a temperature and pressure in the range of 200-400 ° C. in the presence of a hydrogen-containing gas, All of the liquid hydrocarbonaceous feedstock, characterized in that a liquid hydrocarbonaceous product having a low total acid number (TAN) is obtained by contacting with a catalyst essentially free of metals in columns 5-10 or a compound thereof. Method for reducing acid value.   The process according to claim 1, wherein the oxide is a column 4 metal oxide or a lanthanide oxide, preferably titanium oxide or zirconium oxide, more preferably zirconium oxide.   The method according to claim 3, wherein the catalyst contains titanium oxide and / or zirconium oxide as an essential component.   The method according to any one of claims 1 to 3, wherein the pressure is in the range of 2 to 200 bar gauge pressure, preferably 10 to 150 bar gauge pressure, more preferably 25 to 120 bar gauge pressure.   The method according to any one of claims 1 to 4, wherein the temperature is in the range of 250 to 390 ° C, preferably 300 to 380 ° C.   The method according to claim 1, wherein the hydrogen-containing gas is synthesis gas or hydrogen.   The method according to any one of claims 1 to 6, wherein the TAN of the feedstock is 0.2 mgKOH or more, preferably 0.5 mgKOH or more, more preferably 1.0 mgKOH or more per 1 g of feedstock.   The TAN of the liquid hydrocarbonaceous product is 0.2 mgKOH or less, preferably 0.1 mgKOH or less, more preferably 0.05 mgKOH or less, per gram of feedstock. Method.   9. A process as claimed in any one of the preceding claims, wherein the TAN of the liquid hydrocarbonaceous product having a low total acid number is 50% or less, preferably 30% or less, relative to the TAN of the crude product.   The method according to any one of claims 1 to 9, wherein the liquid hydrocarbonaceous feedstock is crude oil.