WO2013091451A1

WO2013091451A1 - Improver for visbreaking and process for co-visbreaking to coal tar or bio-oil containing the same and heavy oil

Info

Publication number: WO2013091451A1
Application number: PCT/CN2012/084531
Authority: WO
Inventors: Carlos A Cabrera; Ke Liu; Li Weng; Xiaofen GUO
Original assignee: Shenhua Group Corporation Limited; National Institute Of Clean-And-Low-Carbon Energy
Priority date: 2011-12-22
Filing date: 2012-11-13
Publication date: 2013-06-27
Also published as: CN103173240A; CN103173240B

Abstract

Disclosed is an improver for vis - breaking processing containing organic oxygen functional groups, such as carbonyl group [-C(O)-]; ether group [R-O-R']; aldehyde group [-CHO]; ketone group [R-C(O)-R']; quinine group [C₆H₄O₂]; furan group [C₄H₄O] and/or any substituted derivative of furan and quinine, wherein R and R' independently are alkyl radicals or other organic groups respectively, as well as a process for co-vis breaking to coal tar or bio-oil containing the above organic oxygen functional groups and heavy oil.

Description

IMPROVER FOR VISBREAKXNG AND PROCESS FOR CO-VISBREAKP G TO COAL TAR OR BIO-OIL CONTAINING

THE SAME AND HEAVY OIL

TECHNICAL FIELD OF THE INVENTION

The present invention is directed to an improvement of viscosity breaking (is referred thereafter to a visbreaking or vis-breaking) processing, more particularly, to an improver for visbreaking processing while the present invention also relates to a process for co-visbreaking to coal tar or bio-oil containing the above improver and heavy oil.

BACKGROUND OF THE INVENTION

Visbreaking is a well known petroleum refining process in which heavy oils including reduced crudes or residual fractions are cracked, or pyrolyzed, under comparatively mild conditions to provide products having lower viscosities, thus reducing the amounts of more valuable and less viscous blending oils (is also referred to cutter stock) required to make the residual stocks useful as fuel oils. The visbreaker feeding stock usually composes one or more refinery streams derived from various sources including vacuum residuum, atmospheric residuum, furfural extract, propane-deasphalted tar and catalytic cracker bottoms etc. Most of these feedstock components, except the heavy aromatic oils, behave independently to each other during the visbreaking operation. Consequently, the severity of the operation for such a mixed feeding stock is limited greatly by the least desirable (highest coke-forming) components. In a typical visbreaking process, the heavy crude or residuum feeding stock is passed through a heater and heated to about 425 °C to about 525 °C at about 450 to about 7000 kPa. A portion of distillates such as light gas oil may be recycled from the product fractionator to quench the visbreaker reactor effluent to about 260 °C to about 370 °C . Cracked products after the reaction are flash distilled with the vapor overhead being fractionated into a light distillate overhead product, for example naphtha such as gasoline, and light gas-oil bottoms, and the liquid bottoms are vacuum fractionated into heavy gas-oil distillate and residual tar. Example of such visbreaking methods is described in U.S 4,233,138.

Generally, visbreaking is deemed as a relatively mild thermal cracking process in which heavy atmospheric or vacuum-distillation bottoms of crude or similar carbonaceous materials are cracked at moderately high temperatures to form light products and produce a lower viscosity residuum than the initial feeding stock to the unit. Vis-breaking process could achieve approximately 30% of residue conversion to lighter products.

On the other hand, visbreaking is supposed to be one of the least costly upgrading processes for poor quality heavy oil material, and is very common where there is still a relative large use of heavy oil. In fact, visbreaking is a well-established non-catalytic or catalytic thermal treating process that converts atmospheric or vacuum treated residues to gas, naphtha, distillates, and cracked residuum or tar. It could be said that visbreaking facilitates to reduce the quantity of cutter stock required to meet fuel oil specifications while reducing the overall quantity of fuel oil produced.

General speaking, the conversion of these treated residues is accomplished by heating the above residue raw material as feedstock to moderately high temperatures in a furnace. The above material is passed through a soaking zone, located either in the heater or in an external drum, under proper temperature and pressure constraints so as to produce the desired products. The heater effluent is then quenched with a quenching medium to terminate the cracking reaction.

Visbreaking units are generally classified into two categories including tubular and tower structures while the visbreaking of feeding stock therein could be carry out in the presence or absence of cracking catalyst well known to those skilled in the art. According to well common general knowledge in the art, visbreaking generally includes normal visbreaking, hydro-visbreak, and hydrogen donor visbreaking etc.

With refineries today processing heavier and heavier crudes and having a greater and greater demand for distillate products, visbreaking gradually shows its importance by offering a low-cost conversion capability to produce incremental gas and distillate products while simultaneously reducing fuel oil viscosity. Visbreaking can be even more attractive if the refiner has idle equipment available that can be modified for this service.

When a visbreaking is considered to upgrade the heavy residual streams derived from crude, the following objectives must be typically realized for such service:

(1) Viscosity reduction of residual streams which will reduce the quantity of high-quality distillates or cutter stock necessary to produce a fuel oil meeting commercial viscosity specifications.

(2) Conversion of a portion of the residual feedstock to distillate products by cracking the feedstock, that is achieved by operating a vacuum flasher downstream of a visbreaker to produce vacuum gas oil cut.

Presently, a number of improvement proposals have been already made for upgrading poor quality residuum stream derived from crude or similar carbonaceous material by visbreaking processes.

For example, US4,292,168 discloses the upgrading of heavy hydrocarbon oils without substantial formation of coke by heating the heavy oil with hydrogen and a hydrogen transfer solvent without a catalyst. This process described in US4,292,168, which uses free hydrogen has the disadvantage, however, of being relatively expensive both in capital outlay and operating costs since pressure vessels and enlarged gas plants are necessary and hydrogen is expensive. It would therefore be desirable to upgrade heavy residuum, other heavy oils, and similar carbonaceous materials without the need for free hydrogen.

US4,615,791 discloses a process in which heavy petroleum oils such as residuum stream are subjected to visbreaking in the presence of a hydroaromatic hydrogen donor solvent having an aromatic and alpha-to-aromatic protons content each of at least 20 % of the total solvent hydrogen. The amount of donor solvent is 0.1 - 50%, preferably 0.1 - 20% by weight of the heavy oil feedstock. The visbreaking may be carried out at relatively high severities as the use of the donor solvent reduces coke of formation as well as producing a product of reduced viscosity, pour point and sedimentation characteristics. Reaction severity in this process is usually in the range of 250 to 1500 (seconds) equivalent reaction time (ERT) at 427 °C but may range up to 15000 (seconds) ERT. Suitable solvents may be obtained from catalytic cracking process, for example, fluid catalytic cracking (FCC) cycle oils, slurry oils and main column bottoms. The above process does not need any solvent separation unit since the above solvent materials are oil materials of which qualities and grades are higher than the heavy petroleum oil feedstock in visbreaker.

US4,298,455 discloses a process for reducing the viscosity of a heavy hydrocarbon oil having an American Petroleum Institute Gravity (API gravity) of less than about 15 while inhibiting polymer formation therein, which comprises subjecting said heavy oil to a visbreaking treatment in the presence of a halogenated hydrocarbon free radical initiator present in an amount between 0.001 and 1.0% by weight of the heavy oil and also in the presence of a chain transfer agent present in an amount between 0.1 and 5.0% by weight of the heavy oil, in which the free radical initiator could a ,a '-azo-bis-iso-butyronitrile and a peroxide such as benzoyl peroxide while the chain transfer agent could be carbon tetrachloride. The materials used as the free radical initiator and the chain transfer agent such as carbon tetrachloride, however, are a little expensive, that prevents it from the it's industrialization applications.

US4,293,404 discloses a process in which the phenolic oxygen and/or the thiol sulfur present in the polycyclic aromatic compounds in a heavy oil, such as vacuum pipestill bottoms, crude oil, reduced crude, vacuum residual oil or tar sands oil, are removed as H₂0 and/or H₂S by contacting the heavy oil with a hydrogen donor at an elevated temperature in the presence of a specified catalyst of an iron-containing porous solid, coal or coal liquefaction residue. Some components of the above specific catalyst as solid particles, however, would exist in final treated heavy oil residuum.

US3,453,202 discloses a process for visbreaking coal tar comprising hydrogenating the coal tar at elevated temperature and pressure in the presence of an iodine catalyst while using as the hydrogenating gas a mixture of hydrogen and diluents gas in a mol ratio of about 25 mol : 75mol - 75 mol : 25mol , and recovering the visbroken coal tar. The above iodine catalyst could be recycled after separation from other components in visbroken solid product, but the apparent char formation still exists in the above process.

US4,356,077 discloses a pyrolysis process in which pyrolytic vapors, produced by the pyrolysis of coal, are contacted with a quench liquid which comprises a hydrogen donor solvent to condense the pyrolytic vapors and form a liquid mixture which comprises pyrolytic condensate. The liquid mixture is separated by vacuum flashing into a vapor containing tar acids and a liquid mixture containing the quench liquid and condensate remainder. This liquid mixture is then heated to transfer hydrogen from the hydrogen donor solvent to the condensate remainder. The hydrogenated liquid mixture is then separated into a heavy hydrocarbon stream and a solvent mixture which contains the spent and unused hydrogen donor solvent. The above process described in US4,356,077 is actually such process as combination of coal pyrolysis process and coal tar hydrogenation process, which is produced by coal pyrolysis.

The disclosures of above-mentioned all patent documents are incorporated hereby in entirety by reference.

It could be obviously seen from the above documents, however, to those skilled in the art that there still are many defects or technical problems needed to be overcome or solved with respect to the prior visbreaking processing. For example, the degree of viscosity reduction is not desirable while the yield of light product including distillates such as naphtha and light gas oil is too low, and coke formation in the final cracked residuum is seriously apparent, thereby amount of the sediments therein is not allowed to be ignored. Furthermore the severity, residence time, temperature, and pressure, as well as harmony among them for visbreaking processing operation need still be improved so as to obtain higher industrial productivity of the visbreaking process.

In the fact, the reduction in cutter stock requirement could be achieved by minimizing the above coke formation in the visbreaker, by excluding the worst coke formers, permitting more severe operation of the visbreaker.

SUMMARY OF THE INVENTION

In accordance with the first aspect of the present invention, there is provided an improver for vis- breaking processing containing organic oxygen functional groups, such as carbonyl group [-C(O)-]; ether group [R-O-R']; aldehyde group [-CHO]; ketone group [R-C(0)-R']; quinine group [C₆H₄O₂] ; furan group [C₄H₄O] ; any substituted derivative of furan and quinine; and/or mixture thereof etc, wherein R and R' independently are alkyl radicals or other organic groups respectively. In accordance with the second aspect of the present invention, there is provided a process for visbreaking heavy oil and/or similar carbonaceous materials.

In accordance with the third aspect of the present invention, there is provided a process for co-visbreaking to coal tar and/or bio-oil containing the above organic oxygen functional groups and heavy oil and/or similar carbonaceous materials.

In accordance with the fourth aspect of the present invention, there is provided a process for co-visbreaking to coal and/or bio-substance pyrolytic vapor containing the improver identified by the present invention and heavy oil and/or similar carbonaceous materials.

In accordance with the fifth aspect of the present invention, there is provided an application of an organic oxygenates including organic oxygen functional group containing [-CO-] and/or [-0-] radical as an improver for visbreaking processing to heavy oils and/or similar carbonaceous materials.

Broadly, the present invention aims at looking for an efficient improver to greatly promote visbreaking, to increase the yield of light products, and to prevent apparent formation of coke or char in visbreaker. We surprisingly found that some certain organic oxygenates could play the above roles.

Meantime it has been ascertained that the above these specific organic oxygenates almost exist in all types of coal tar and bio oil produced by rapid and medium & low temperature pyrolysis of coal or bio-substances. Thus the present inventor(s) smartly conceived out the above process for co-visbreaking to coal tar and/or bio-oil containing the above organic oxygenates and heavy oil and/or similar carbonaceous materials after numerous experiments.

Therefore, it is an object of this invention to provide with a less costly improver for visbreaking processing; it is another object of this invention to efficiently reduce the viscosity of mixture of heavy oil and/or similar carbonaceous materials and coal tar and/or bio oil by co-visbreaking while minimizing the formation of char and sediments produced in visbreaker. Another still object is to convert mixture of heavy oil and/or similar carbonaceous materials and coal tar and/or bio oil, as difficulty pumpable oil, into one which may be pumped from the production site to a petroleum refinery. These and other objects will be obvious to those skilled in the art from the following disclosure.

According to the present invention, the process enables mixture feed stocks of heavy oil and/or similar carbonaceous materials and coal tar and/or bio oil to be efficiently visbroken or thermally cracked at high severities to provide with fuel oil and other products of improved viscosity and pour point. In addition, the need for cutter stock to meet fuel oil commercial viscosity specifications is substantially reduced and, in favorable cases, may be eliminated. Furthermore, the products formed by the present invention are also notable for their improved low sedimentation characteristics.

As mentioned above, according to the first aspect of the present invention, there is provided an improver for visbreaking processing to heavy oils and/or similar carbonaceous materials comprising: at least one organic oxygen functional group.

Generally, the above organic oxygen functional group includes [-CO-] and/or [-0-] radical, for example carbonyl group [-C(O)-]; ether group [R-O-R']; aldehyde group [-CHO]; ketone group [R-C(0)-R']; hydroxyl group [-OH]; quinine group [C₆H₄O₂] ; furan group [C₄H₄O] ; any substituted derivative of furan and quinine; and/or mixture thereof , wherein R and R' independently are alkyl radicals or other organic groups respectively.

Preferably, the exemplary examples, without limitation, of the above improver are 3-hydroxy-4-methoxy-phenol, furan, quinine, 4-hydroxy-3-methoxy-phenol, 4-hydroxy-3-methoxy-benzeneacetic acid, dibenzofuran, 2-methoxy-4-methylphenol, 3,4-dimethoxybenzoic acid, 2-methoxyphenol, aldehyde, 4-ethyl-2-methoxyphenol, l,4-dimethoxy-2-methylphenol, acetic acid, 2-methoxy-6-(l-propenyl)phenol,

3.4- dimethoxyphenol, 2-methoxy-5-(l -propenyl)phenol, 2,6-dimethoxyphenol, 2-methoxy-4-(l-propenyl)phenol, 4-hydroxy-3-methoxybenzoic acid, benzofuran,

2.5- dimethoxybenzyl alcohols, (l,l-dimethylethyl)-l,2-benzenediol, CrC₂ substituted benzofuran, methanol, l-(4-hydroxy-3-methoxyphenyl)ethanone, hydroxyl-propanone, 3,4-dimethoxyphenol, 3,4-dimethoxybenzoic acids, 2-methoxy-4-ethylphenol, multi-substituted benzofuran, ethanediol, 2,6-dimethoxy-4-(2-propenyl)-phenol, 2-methoxy-dibenzofuran, 2,3-diacetyl, 1-hydroxyl- aldehyde, propanoldiacid, and any substituted derivative and /or mixture thereof.

Also preferably, the exemplary examples, without limitation, of the above improver could also be at least one component as organic oxygenate existing coal tar and /or bio oil.

In the most circumstances, the above heavy oils have API Gravity (American Petroleum Institute Gravity) of less than 22.3, preferably less than 16, the exemplary examples of such heavy oils include at least one component selected from group consisting of residual fractions obtained by catalytic cracking of gas oils, solvent extracts obtained during the processing of lube oil stocks, asphalt precipitates obtained from deasphalting operations, high boiling bottoms or residuum obtained during vacuum distillation of petroleum oils, tar sand bitumen, vacuum pipestill bottoms, crude oil, reduced crude, vacuum residuum, heavy residual oil, coal liquefaction residue, or oil recovered from tar sands.

Of course, the above heavy oils could or could not derive from petroleum while the similar carbonaceous materials may include coal tar and/or bio oil , preferably, the coal tar or bio oil is that type of one produced by rapid and medium & low temperature pyrolysis of coals or bio substances, more especially, the above rapid and medium & low temperature pyrolysis of coals or bio substances is meant that the coals or bio substances is pyrolyzed under temperature of more than 450 °C but less than 750 °C within time of less than 45 minutes. General speaking, the similar carbonaceous materials could include mixture of coal tar or bio oil and the heavy oils or mixture of coal tar, bio oil and the heavy oils.

There generally are no special restrictions to the used amount of the improver, however, for the economic consideration, preferably, the improver is used in amount of 0.1-50%, more preferably 0.5-30%, based on weight of oxygen therein, by weight of the heavy oils and/or similar carbonaceous materials.

Also as mentioned above, according to the second aspect of the present invention, there is provided a process for visbreaking heavy oil and/or similar carbonaceous materials, comprising: the heavy oil and/or similar carbonaceous materials is subjected to visbreaking in the presence of the above mentioned improver, which is used in amount of about 0.1-50 %, preferably 0.5-30%, more preferably 1-20%, most preferably 1.5-15%, based on weight of oxygen therein, by weight of the heavy oils and/or similar carbonaceous materials.

According to the third aspect of the present invention, there is provided a process for co-visbreaking to coal tar and/or bio-oil containing the above mentioned improver and heavy oil and/or the similar carbonaceous materials, comprising: a mixture of the coal tar and/or bio-oil and heavy oil and/or the similar carbonaceous materials is subjected to visbreaking, mixing ratio of which is total weight of the coal tar and/or bio-oil/total weight of heavy oil and/or the similar carbonaceous materials of 1/99 - 99/1. Preferably, in the above process, the total weight of the coal tar and/or bio-oil/ the total weight of heavy oil and/or the similar carbonaceous materials further is 10/90 - 90/10, more preferably 20/80 - 80/20, particularly preferably 30/70-70/30, most preferably 40/60 - 60/40.

It needs to be said that the coal tar, bio oil, heavy oil and similar carbonaceous materials could be used alone or in combination, it is meant that the coal tar or bio-oil may be not used while the heavy oil or similar carbonaceous materials may also be not used, wherein the heavy oil is non- petroleum oil.

In the above processes according to the present invention, visbreaking operation severity is generally in range of 250 - 1500, preferably 400 - 1000 , more preferably 500 - 900, particularly preferably 600-800, most preferably 650-750, for example 700 equivalent reaction time (ERT) seconds at 427 ^°C ( 800^' F). in the same way, the visbreaking is usually carried out at a temperature 350 ^°C - 525 ^°C , preferably 375 ^°C - 515^°C , more preferably 425 ^°C - 485 ^°C , most preferably 445 ^°C - 465 ^°C with a residence time of 1 - 60, preferably 1 - 30, more preferably 1 - 20, most preferably 1 - 15 minutes, under a pressure of 0.3 - 10, preferably 0. 45 - 7, more preferably 0.6 - 6, most preferably 1.5 - 5MPa. On the other hand, the visbreaking defined by the present invention is any one of normal visbreaking, catalytic visbreaking, hydro visbreaking, hydrogen donor visbreaking etc.

According to the fourth aspect of the present invention, there is provided a process for co-visbreaking to coal and/or bio-substance pyrolytic vapor containing the improver identified by the present invention and heavy oil and/or similar carbonaceous materials, comprising: a mixture of the coal and/or bio- substance pyrolytic vapor and heavy oil and/or the similar carbonaceous materials is subjected to visbreaking, mixing ratio of which is total weight of the coal and/or bio— substance pyrolytic vapor /total weight of heavy oil and/or the similar carbonaceous materials of 1/99 - 99/1

According to the fifth aspect of the present invention, there is provided an application of an organic oxygenates including organic oxygen functional group containing [-CO-] and/or [-0-] radical as an improver for visbreaking processing to heavy oils and/or similar carbonaceous materials.

BRIEF DESCRIPTION OF THE DRAWINGS

The Figure 1 of the accompanying drawings shows a simplified flow diagram of a visbreaking process using the improver according to the present invention.

DETAILED DESCRIPTION OF THE BEST MODE FOR IMPLEMENTING THE INVENTION:

The present invention is practiced by mixing heavy oils and/or similar carbonaceous materials and at least one organic oxygenate containing [-CO-] and/or [-0-] radical, and then obtained mixture being subjected to visbreaking processing at an elevated temperature to evolve H₂0, CO and/or C0₂ from the mixture. The visbroken heavy oils have lower viscosity which improves its pumping characteristics and a lower oxygen content which makes the oil more susceptible to conventional petroleum processing.

As described above, the exemplary examples of the above [-CO-] and/or [-0-] radical may include carbonyl group [-C(O)-]; ether group [R-O-R']; aldehyde group [-CHO]; ketone group [R-C(0)-R']; hydroxyl group [-OH]; quinine group [C₆H₄0₂]; furan group [C₄H₄O] ; any substituted derivative of furan and quinine; and/or mixture thereof , wherein R and R' independently are alkyl radicals or other organic groups respectively. Theoretically, during visbreaking or thermal cracking, the above organic oxygen functional groups could be expected to, for example, take place the following reactions:

R-CO-R'( or OH, H) → R- + CO + -R' (or OH (1)

R-O-R' → R"- + CO + xH⁺ + -R' (wherein R"CH_X = R) (2) R-O-R' + CO -R'+ C0₂ (3) R-OH + H⁺ + H₂0 (4)

On the other hand, if oxygen is included in the organic heterocycle, for example furan, quinine and/or substituted derivative thereof, the heterocycle will be broken by the following reaction:

CO + H⁺ + - CHCHCH- (5)

In this way, the above organic oxygen functional groups indeed become hydrogen donors and /or free radical fragments generators with small molecular weight during visbreaking or thermal cracking, such highly active hydrogen protons and free radical fragments then compete with the larger chain hydrocarbons to prevent from the formation of tar or coke in visbreaker. In the same time, unsaturated hydrocarbons react with the above free radicals to form saturated hydrocarbons which cannot be polymerized further. With proper control of the quantity of organic oxygenates containing the above organic oxygen functional groups added to the heavy oils and/or similar carbonaceous materials to be visbroken, and adjustment of the residence time at visbreaking reaction temperature, the formation of coke can be greatly reduced or even eliminated while obtaining a substantial reduction in the viscosity of the heavy oils and/or similar carbonaceous materials.

In fact, the polymerization during visbreaking or thermal cracking is inhibited by the use of the above organic oxygenates which readily generate hydrogen protons and/or free radicals fragments so that only lower molecular weight hydrocarbons are produced during the cracking step. The higher molecular weight hydrocarbons are cracked at high temperatures before they are repolymerized as they would be in conventional thermal cracking or visbreaking processes.

Now it has already been ascertained that -O- bridge bond is the weakest link in the hydrocarbons structure, which is readily broken to be capable of generating free radicals "fragments" by the thermal effect. It is attested by Electron Spin Resonance (ESR) measurement that the concentration of the above free radicals will rise with higher temperature, slowly rise at temperature of below 400 ^°C , promptly increase at the temperature above its decomposition point, and reach its peak value at temperature of approximating 500 ^°C , then sharply decline at the temperature of more than 550 ^°C . General speaking, the thermal stability of organic oxygen functional groups in order is -OH > C=0 > -COOH > -OCH₃, hydroxyl is not readily removed out from hydrocarbon structure by heating, only could be converted into H₂0 at the temperature of about above 700 ^°C and in the presence of hydrogen; carbonyl could be cracked at the temperature of about 400 ^°C to form CO; carboxyl thermal stability is very low, could be cracked even at the temperature of about 200 ^°C to form C0₂ and H₂0, in addition, organic heterocycle containing oxygen could be broken at the temperature of about 500 ^°C to emit CO. It has been attested by numerous experiments that almost all kinds of organic oxygen functional groups are used as hydrogen donors and /or free radical fragments generators if the strength of their effects is not over emphasized. In general circumstances, the exemplary examples, without special limitation, of the organic oxygenates containing the above organic oxygen functional groups preferably are

3- hydroxy-4-methoxy-phenol, furan, quinine, 4-hydroxy-3-methoxy-phenol,

4- hydroxy-3-methoxy-benzeneacetic acid, dibenzofuran, 2-methoxy-4-methylphenol, 3,4-dimethoxybenzoic acid, 2-methoxyphenol, aldehyde, 4-ethyl-2-methoxyphenol, l,4-dimethoxy-2-methylphenol, acetic acid, 2-methoxy-6-(l-propenyl)phenol,

2.5- dimethoxybenzyl alcohols, (l,l-dimethylethyl)-l,2-benzenediol, CrC₂ substituted benzofuran, methanol, l-(4-hydroxy-3-methoxyphenyl)ethanone, hydroxyl-propanone, 3,4-dimethoxyphenol, 3,4-dimethoxybenzoic acids, 2-methoxy-4-ethylphenol, multi-substituted benzofuran, ethanediol, 2,6-dimethoxy-4-(2-propenyl)-phenol, 2-methoxy-dibenzofuran, 2,3-diacetyl, 1-hydroxyl- aldehyde, propanoldiacid, and any substituted derivative and/or mixture thereof; and more preferably are those containing carboxyl and /or alkoxyl; and most preferably are those containing methoxyl, ethoxyl, and /or propoxyl.

It has already been found now that the large amount of organic oxygenates containing the above organic oxygen functional groups exists in coal tar and/or bio oil, especially those produced by rapid and medium & low temperature pyrolysis of coal and bio substances, for example those produced by pyrolysis of coal and bio substances at the temperature of more than 450 °C , but lower than 750 °C within the time of less than 45 minutes.

Generally, composition of coal tar and/or bio oil could greatly vary dependent to their types and geologic sites. The chemical composition of typical coal tar produced by rapid and lower temperature pyrolysis, based on dried components, is shown in table 1.

Table 1

The elemental analysis (weight %) of typical coal tar produced by rapid and lower temperature pyrolysis is shown in table 2.

Table 2

Test No. pyrolysis C% H% N% S% o% H/C temperature/ ^'C atom ratio

T-l 500 81.66 8.85 0.77 0.22 8.50 1.30

T-2 550 80.50 8.11 0.89 0.25 10.26 1.21

T-3 600 80.18 7.48 1.19 0.47 10.78 1.12

T-4 650 82.43 6.94 1.31 0.58 8.74 1.01 The chemical composition of typical bio oil produced by rapid and lower temperature pyrolysis of saw dust is shown in table 3.

Table 3

It is be apparently seen from the above tables 1-3 that about 50 - 55 wt components of both coal tar and/or bio oil are organic oxygenates containing the organic oxygen functional groups identified by the present invention, which is quite different from the chemical composition of heavy oils and /or similar carbonaceous materials. Some characteristic properties of the typical coal tar and heavy diesel oil (HDO) are shown in table 4.

Table 4

Subject Coal tar (HDO) oil

Water 15 <5

Acid number (mg KOH/g) 60 30-35 Oxygenate content, weight % 50-55 10-15

Organic volatiles (300 ^'C) 75-80 75-85

Evaporation residue (200 ^'C) 30-35 25

The elemental analysis (weight) of typical heavy oil from petroleum is shown in table 5

Table 5

It is remarkably shown by above tables 1-5 that the organic oxygenates or oxygen content present in the heavy oils and /or similar carbonaceous materials is much less than that in the coal tar and/or bio oil, that is meant that during visbreaking or thermal cracking, the amount of hydrogen protons and /or free radical fragments generated by the above organic oxygenates in the heavy oil and /or similar carbonaceous materials is also much less than that generated by the above organic oxygenates in the coal tar and/or bio oil. If a certain amount of the coal tar and/or bio oil is added into the heavy oil and /or similar carbonaceous materials to increase the amount of the above organic oxygenates in the heavy oils and /or similar carbonaceous materials, the hydrogen protons and /or free radical fragments in the heavy oil and /or similar carbonaceous materials would be greatly enhanced, as a result, increment of hydrogen protons and free radical fragments substantially prevents from the occurrence of polymerization and formation of char and/or molecule fragments with large molecular weight while forming a lot of molecules with small molecular weight. In this way, the viscosity of visbroken heavy oils is greatly reduced so that it could be pumped for transportation after mixing with smaller quantity of cutter stock while meeting fuel oil commercial viscosity specifications; and the yield of light products and/or distillates, for example gas, naphtha, and light gas oil is greatly increase; furthermore the operation severity of visbreraking reaction could become higher than usually, so as to lower the cost of production and maintenance.

More importantly, the process, according to the present invention, for co-visbreaking to coal tar and/or bio oil containing the above organic oxygenates as an improver and heavy oil and/or similar carbonaceous materials is a very low cost process because it does not need pure or separate organic oxygenates, hydrogen donors and /or free radical fragments generators of which prices sometime are very high.

Generally, in the specification of the present invention, the coal of "coal tar" refers to all types of coal or similar solid carbonaceous materials including coal liquefaction residue, oil shale, oil sand, and even industrial and metropolitan carbonaceous wastes or tailings. The pyrolysis system or method of the above coal or similar solid carbonaceous materials is please referred to the disclosure in US 4,356,077, the disclosure of this patent document is incorporated hereby in entirety by reference.

In the same way, in the specification of the present invention, bio substances of "bio oil" are meant the liquid fraction obtained by the pyrolysis, especially fast pyrolysis of such carbonaceous substances derived from all kinds of animals or plants except for fossil fuel, for example as at least one component selected from a group consisting of agricultural and forest wastes including saw dust, timbering residue, and wood or crop leftover material; aquatic plants; energetic botanic materials; metropolitan garbage; industrial waste, tailing or sludge; organic used water and even excrements of human or animal etc. The bio-oil is generally obtained from the product vapour which is produced along with char by pyrolysis. Upon removal of the char the product vapour is condensed and collected within one or more condensers which are typically linked in series. Bio-oil sometimes refers also to the combination of the condensed products obtained from all of the condensers.

The bio-oil used in the present invention could be prepared by a fast pyrolysis reactor, and such pyrolysis systems are known within the art, for example US 5,792,340, or WO 91/11499. Fast pyrolysis of such carbonaceous material, associated residues or wastes results in the formation of product vapors and solid char. After removal of the char components from the product steam, the product vapours are condensed to obtain a bio-oil product by pyrolysis. The disclosures of above those both patent documents are incorporated hereby in entirety by reference.

Pyrolysis of coal, bio- substances and similar solid carbonaceous materials can produce a heavy viscous tar. The tar produced can be semi-solid or even solid and can have a very low hydrogen content. For example, the hydrogen-to-carbon ratio of tar produced by pyrolysis can typically be about 1.0-1.3. In the past time, in order to produce a marketable product, tar which have been produced by pyrolysis have been hydrogenated by gaseous hydrogen to increase the hydrogen content and to remove some of the hereto atoms, for example oxygen, nitrogen and sulfur.

It is believed that the initial step in the above pyrolysis is the thermal generation process of hydrocarbon free radicals via homolytic bond scission. These hydrocarbon free radicals can be terminated by hydrogen or small molecule fragments to produce tar and gas products, or they can combine with each other to produce undesirable heavy large molecules such as heavy viscous tars having a boiling point above the boiling point of desirable middle distillate tar. Ultimately, the hydrocarbon free radicals can continue to grow or combine with a carbon site to form char. It is known the polymerization and cracking of tar could take place rapidly at higher temperatures. Generally, vapors from pyrolysis have been condensed by using either direct or indirect cooling to minimize the occurrence of secondary reactions involving combination of lighter hydrocarbon molecules into the heavier, less desirable large molecules. Condensation by rapid cooling has had some effect on preventing tar from cracking, but is not completely satisfactory in preventing tar liquids from polymerizing by free radical recombination. A pyrolysis process is, therefore, desired which substantially eliminates secondary reactions in pyrolysis products and hydrogenates the pyrolysis products by using less severe operating conditions, thereby economically enhancing the yield of lower molecular weight coal-derived liquids.

In fact, the coal tar and bio oil used in present invention is liquid hydrocarbons from pyrolytic vapors produced by the pyrolysis of coal, bio-substances or coal-like carbonaceous solid materials. Pyrolytic vapors produced by the pyrolysis of the above coal, bio substances or coal-like materials have a broad range of molecular weights, boiling points, and hence viscosities, which range from very fluid and volatile liquid hydrocarbons such as benzene, to very heavy asphaltenes, preasphaltenes, tars, and pitches. Generally, the more is aromaticity of the above coal, bio-substances or coal-like carbonaceous solid materials and the lower is pyrolysis temperature and the shorter is pyrolysis time in the pyrolysis zone at an elevated temperature, the higher will be the molecular weights of the pyrolytic vapors, and the higher will be the boiling points and viscosities of the subsequently formed liquids. Higher molecular weight pyrolysis vapors are both difficult to recover and easily self polymerizable.

It has already been found now that almost all kinks of the organic oxygenates containing the above - mentioned organic oxygen functional groups exist in the above coal tar and /or bio oil. The above organic oxygenates and/or organic oxygen functional groups have been identified and/or analyzed by prior measurements well known to those skilled in the art, for example, GC, TG, GC-MS, GPC, HPLC, CNMR, HNMR, NMR, MS, IC, XRD, XPS, XAFS, SAXS, TG-DTA, and/or FTIR etc. Similarly, in the specification of the present invention, By "heavy oil" is meant a relatively high boiling petroleum or non petroleum based oil, such as at least one component selected from a group consisting of residual fractions obtained by catalytic cracking of gas oils, solvent extracts obtained during the processing of lube oil stocks, asphalt precipitates obtained from deasphalting operations, high boiling bottoms or residuum obtained during vacuum distillation of petroleum oils, tar sand, bitumen, vacuum pipestill bottoms, crude oil, reduced crude, vacuum residuum, heavy residual oil, coal liquefaction residue or oil recovered from tar sands. The "heavy oil" which may serve as the feedstock in the practice of this invention may be described as petroleum or non petroleum-derived heavy blacktop oil having an API gravity of preferably less than about 22.3, more preferably less than 16, most preferably less than 15, generally less than about 25, a Conradson carbon value of above about 5.5, a distillate yield of less than 50% and a viscosity of above about 1000 SUS at 37.8 °C (100^' F). These heavy oils are generally composed of a great variety of hydrocarbons including polycyclic aromatic compounds which are of major concern during the processing of these heavy oils to produce useful products. If no subjecting these heavy oils to very efficient visbreaking or thermal cracking, the presence of large amount of molecule fragments with high molecular weight in the polycyclic aromatics of these heavy oils creates a variety of processing problems, for example increasing pumping costs because of high viscosity thereof.

In addition to the specific examples provided herein, of course, other heavy oils which come within the above description may also benefit from the process of this invention.

The heavy oil feeds used in the present invention may also be a single refinery stream or a mixture of refinery streams derived from various sources. The present invention is suitable for visbreaking a wide variety of heavy liquid hydrocarbon oils in which at least 75% by weight of the components boils over 370 °C . Exemplary examples included in this class of feedstock are residual fractions obtained by catalytic cracking of gas oils, solvent extracts obtained during the processing of lube oil stocks, asphalt precipitates obtained from deasphalting operations, high boiling bottoms or residuum obtained during vacuum distillation of petroleum oils, tar sand, bitumen and the like. These heavy oils usually contain heteroatom impurities such as nitrogen or sulfur as well as having relatively high metal contents.

In the specification of the present invention, the similar carbonaceous materials are the substitutes of the heavy oil, which are similar to the heavy oil in aspects of chemical and elements compositions and properties, for example it could also be liquid hydrocarbon substances.

The process according to the present invention may suitably be carried out in a visbreaking system of the type shown diagrammatically in the accompanying drawing. Referring to the Figure 1 now, a viscous hydrocarbon oil feedstock, for example a 496 °C ⁺ Arabian Heavy residuum, is supplied by line 22 to visbreaking heater 25. The above feedstock is blended with the above-mentioned organic oxygenates or containing the above-mentioned organic oxygenates stream, for example coal tar, bio-oil and/or pyrolytic vapors supplied through line 50 in an amount 0.1 to 50 weight %, based on weight of oxygen therein, preferably 0.5 to 30 weight %, more preferably 1-20%, most preferably 1.5-15% by weight of the above heavy oils. Mild thermal cracking of the above residuum under visbreaking conditions occurs in visbreaker 25 and produces a visbreaker effluent stream transported by line 28. This stream is cooled by admixture with a quench stream from line 31, and the visbreaker effluent continues through line 29 to enter fractionator 30 where it is fractionated to obtain C₅ - gases (C₃, C₄ and lower) and a C₅ - 165°C naphtha fraction, for example gasoline from the top through line 34. A about 165°C - 315°C gas oil fraction may be taken off as a middle fractioned stream through line 33 and then is supplied by line 32 to distillate stripper 60 where the above gas oil fraction is distillated by steam supplied by line 62 to generate light gas oil which exits by line 64 from the bottom of distillate stripper 60 while more light oil and /or the steam is charged by line 66 into the upper portion or top of fractionator 30. The portions of the above gas oil fraction may be recycled as a quench stream through line 31, recovered visbroken residue as fuel oil raw material is supplied by line 39 to blender 70 where the above visbroken residue is blended with cutter stocks supplied by line 72 to produce fuel oil, transported by line 74, of which viscosity is required to meets fuel oil product commercial specifications, in which the above cutter stocks could be a portion of the above light gas oil which exits by line 64 from the bottom of distillate stripper 60 or derived from other resources.

In the same time, admixture of the C₅ - gases and C₅ - 165°C naphtha, as overhead fraction, exiting from the top of fractionators 30 through line 34 is charged into a gas-liquid separator or cooler separator 36 to be separated into the C₅ - gas, mainly C₃ or C₄ and lower, transported by line 38 and C₅ - 165 °C naphtha fraction, for example gasoline, transported by line 40.

Any conventional distillation methods may be used to process the visbreaker reactor effluent. In conventional visbreaking operations, it is preferred to quench the visbreaker effluent with a quench stream as shown in the Figure 1 of drawing, but it can also be possible to use any heat exchanger, fin/fan coolers, or some other conventional means of cooling the visbreaker effluent. However, since there is a risk of coking up the heat exchanger tubes in such an arrangement, the use of a quench stream is preferred.

In most hydrocarbon treating processes, there is a tradeoff between reaction temperature and residence time of reactants. Because visbreaking is a well-known and widely practiced process, correlations between them have been widely developed so that it is possible to express precisely the severity of the visbreaking process. An expression of the "severity" of a particular visbreaking operation does not mean that a certain degree of conversion can be predicted or obtained or that a certain amount of coke or sediment will be formed; rather it means that it is possible to predict that if all other reaction parameters are unchanged (e.g., feedstock composition, reactor pressure) except for the temperature and residence time in the reactor, two operations can be compared and it can be determined whether one process is more severe than the other.

ERT (equivalent reaction time) refers to the severity of the operation, expressed as the equivalent number of seconds of residence time in a reactor operating at 427 °C (800^' F.). In very general terms, the reaction rate doubles for every 12 °C to 13 °C increase in temperature. Thus, 60 seconds of residence time at 427 °C is equivalent to 60 ERT

The visbreaking process conditions which may be used in the present invention can vary widely based on the nature of the heavy oil material, the organic oxygenates material and other factors. In general, the process according to the present invention could be carried out at temperatures ranging from 350 °C to 525 °C , preferably 375 °C to 515 °C , more preferably 425 °C -485 °C most preferably 445 °C - 465 °C at residence times ranging from 1 - 60 minutes, preferably 1-30 minutes, more preferably 1 to 20 minutes, most preferably 1 - 15 minutes. Expressed as ERT, the process of the invention generally operates at an Equivalent Reaction Time in range of 250 - 1500, preferably 400 - 1000 , more preferably 500 - 900, particularly preferably 600-800, most preferably 650-750, for example 700 equivalent reaction time seconds at 427 °C ( 800^° F).

On the other hand, the above visbreaking defined by the present invention refers to any one of normal visbreaking, catalytic visbreaking, hydro visbreaking, hydrogen donor visbreaking etc.

The limit of severity is determined primarily by product quality. Visbreaking is an inexpensive process, and once a visbreaker has been installed, it does not cost much more to run it at high severity in order to achieve the maximum viscosity reduction possible with a given feed stock. However, the two limiting factors in the visbreaker operation are the formation of coke (which tends to plug the coil and/or soaking drum used in the visbreaker and also take the product out of specification) and sediment formation in the product. Sediment formation is a complicated phenomenon.

An important aspect of the invention is the improvement of visbreaker performance by optimizing operational severity for heavy oil feedstocks. In general, as severity is increased, increased yields of distillate and gaseous hydrocarbons are obtained with a reduction in the viscosity of the visbroken products so that the amount of cutter oil required for blending to obtain specification— viscosity residual fuel oil is also reduced.

The pressure employed in a visbreaker will usually be sufficient to maintain most of the material in the reactor coil and/or soaker drum in the liquid phase. Normally the pressure is not considered as a control variable, although attempts are made to keep the pressure high enough to maintain most of the material in the visbreaker in the liquid phase. Generally speaking, however, the pressures commonly encountered in visbreakers range from 0.17- 10.450 MPa, with a vast majority of units operating with pressures of 1.48 to 7 MPa. Such pressures will usually be sufficient to maintain liquid phase conditions and the desired degree of conversion. Usually, in the present invention, the pressure in a visbreaker could be 0.3 - 10, preferably 0. 45 - 7, more preferably 0.6 - 6, most preferably 1.5 - 5MPa.

Some vapor formation in the visbreaker is not harmful, and is frequently inevitable because of the production of some light ends in the visbreaking process. Some coil visbreaker units operate with 20-40% vaporization material at the visbreaker coil outlet. Lighter solvents will vaporize more and the vapor will not do much good towards improving the processing of the liquid phase material. Accordingly, liquid phase operation is preferred, but significant amounts of vaporization can be tolerated.

The visbreaker unit itself may be conventional in form, typically of the coil, i.e. a tubular reactor which is entirely in the heater or drum type or with a combination of coil and drum in order to provide the requisite residence time under the temperature conditions employed. As far as product type and distribution is concerned, it is of no great significance whether the residence time is obtained in a coil, drum, or combination of both. Typical of the coil/drum combinations is the unit disclosed in U.S. Pat. No. 4,247,387.

EXAMPLES

A series of visbreaking experiments on heavy residual stock was carried out with residuum feeds of Arabian heavy residual stocks.

EXAMPLE 1:

The experiment was carried out in a laboratory visbreaker, essentially a batch reactor which closely simulated a commercial visbreaker.

The feedstock physical properties and elements analysis were as set out in Tables 6 and 7 below respectively:

Table 6

Physical Properties of Arabian Heavy Residual Stock

Nominal initial boiling point, ^'C 494

Viscosity, cSt at

100^"C 4678.1

150^"C 935.8 Pour point, ^'C 47.7

API 6.1

Aromatics sulfur content, weight % 5.1

Conradson Carbon Residue (CCR), weight % 17.9

Table 7

The cutter stock used to dilute the product to meet viscosity specifications had the physical properties given in Table 8 below.

Table 8

Cutter Stock Physical Properties

API 37.4

Distillation by ASTM-D86 ^•c

10% 243

30% 251

50% 262

70% 283

90% 301

Kinematic Viscosity (50 ^'C), cSt 2.64 The Arabian heavy residual stock was visbroken at 800 ERT seconds at 427 °C (800^' F) in the presence of the organic oxygenate in amount of 2%, 5%, 10% and 20% by weight of Arabian heavy residual stock. After visbreaking, cutter stock was added to reduce viscosity to meet product specifications. Accordingly, the viscosity, pour point and sedimentation results were reported in Table 9 below respectively. The viscosity and pour point tests were conducted before the cutter stock was added and the sedimentation test afterwards. The sediment test used was the centrifuge method used to determine the compatibility of sediment in blended fuel oil. This method is used to determine the volume percentage of incompatible sediment in blended fuel oils.

A 100 ml sample of the blended fuel oil was centrifuged in a heated centrifuge at 65.5+1 °C for 3 hours at a relative centrifugal force of 700 units. Further details of the centrifuge operation can be taken from ASTM D-96.

Another commonly used test method is a hot filtration test which gives weight percentage of sediment after hot filtration and washing with normal hexane. All testing reported in this specification use the hot centrifuge method so results are reported in volume percent of sediment. In the sediment tests reported here, there is no dilution of the sample, rather the sample is charged to the centrifuge without dilution. The obtained results are reported in Table 9 below.

Table 9

3 ,4-dimethoxyphenol, 2 w % 5 w % 10 w% 20 w %

Viscosity, cSt at 82^'C 975 814 706 547

Pour Point at ^'C 34 25 23 15

Added cutter stock w % 10 10 10 10

COMPARATIVE EXAMPLE 1

The experiment in the example 1 repeated except that the organic oxygenate used in the example 1 was not added to visbreaker feedstock and visbroken product. The obtained results were reported in Table 10 below.

Table 10

It is seen from comparison between example 1 and comparative example 1 that the benefits of adding, only 2 w% the organic oxygenate, i.e. 3,4-dimethoxyphenol to the visbreaker feed are evident. The viscosity has been significantly reduced by the addition of only 2 w% 3,4-dimethoxyphenol to the feed, rather than to the product of the visbreaker.

The pour point of the product has been significantly reduced also: 2 w% 3,4-dimethoxyphenol reduced the pour point from 47 °C to 34°C . Similar result was obtained with the addition of 5 w% 3,4-dimethoxyphenol, reducing the pour point from 47 °C to 25 °C . The visbroken product of the invention had only an acceptable amount of sediment. In contrast, the visbroken product obtained without the use of the organic oxygenate prior to visbreaking approximately produced 0.8 % sediment by addition of cutter stock.

EXAMPLE 2

The example used the same cutter stock as in example 1 and another type of Arabian heavy residual stocks of which physical properties were as set out in Table 11 below:

Table 11

Arabian Heavy Residual Stock Physical Properties

Nominal initial boiling point, ^'C 451

Viscosity, cSt at

100^"C 995.4

150^"C 83.6

Pour point, ^'C 37.3

API 7.9

Aromatics sulfur content, weight % 4.6

Conradson Carbon Residue (CCR), weight % 15.7

The experiment in the example 1 repeated except that the 3,4-dimethoxyphenol and Arabian heavy residual stocks shown in tables 6 and 7 were substitute by dibenzofuran and another Arabian heavy residual stocks shown in table 11 respectively. The obtained results are reported in Table 12 below.

COMPARATIVE EXAMPLE 2 The experiment in the example 2 repeated except that the organic oxygenate i.e. dibenzofuran used in the example 2 was not added to visbreaker feedstock and visbroken product. The obtained results were also reported in Table 12 below.

Table 12

These data shows that a significant reduction in the amount of sediment in the visbroken product after addition of cutter stock can be obtained by the use of the organic oxygenate identified by the present invention during the visbreaking while the viscosity of the visbroken product could also be remarkably decreased.

EXAMPLE 3

The experiment in the example 2 repeated except that the dibenzofuran was substitute by a series of following listed organic oxygenates. The obtained results are reported in Table 13 below.

COMPARATIVE EXAMPLE 3

The experiment in the example 3 repeated except that the organic oxygenates used in the example 3 was not added to visbreaker feedstock and visbroken product. The obtained results were also reported in Table 13 below.

Table 13 Viscosity, cSt at Pour Point Added cutter Sediment

10 w% oxygenates 54.5 ^°C at ^°C stock w % Volume %

3,4-dimethoxybenzoic acids 169.1 -8 15 0.8 example aldehyde 197.4 -5 15 0.9

3 2,3-diacetyl 220.5 -4 15 1.23 l-(4-hydroxy-3- 233.7 -3 15 1.36 methoxyphenyl)ethanone

jmparative

ixample 0 w % oxygenates 1350.8 37 15 3.4

3

It is apparently seen from table 13 that the result in example 3 is similar to that in example 2, by the use of a series of organic oxygenates identified by the present invention during the visbreaking, the amount of sediment in the visbroken product after addition of cutter stock and the viscosity of the visbroken product both were remarkably decreased.

EXAMPLE 4

The Arabian heavy residual stock, shown in the table 11, was visbroken at 800 ERT seconds at 427 °C (800^' F) in the presence of the organic oxygenate i.e. acetic acid in amount of 5% by weight of the Arabian heavy residual stock. After visbreaking, cutter stock was added to reduce viscosity to meet product viscosity specifications. Accordingly, the viscosity of the visbroken product and yields of distillates were reported in Table 14 below respectively. The viscosity tests were conducted before the cutter stock was added.

COMPARATIVE EXAMPLE 4

The experiment in the example 4 repeated except that the organic oxygenates used in the example 4 was not added to visbreaker feedstock and visbroken product, as well as severity of visbreaking operation was changed to 500 ERT seconds at 427 °C (800^° F) from 800 ERT seconds at 427 °C (800^° F). The obtained results were also reported in Table 14 below.

Example 4 and comparative example 4 compared the results of a conventional visbreaking operation under 500 ERT seconds at 427 °C without addition of the organic oxygenate with visbreaking operation by adding the organic oxygenate therein at higher severity of 800 ERT seconds at 427 °C . The feed used was the 451 °C ⁺ Arabian heavy residuum shown in the table 11.

Table 14

Residuum visbreaking condition Example 4 Comparative example 4

Severity, ERT at 427 ^"C 800 500 oxygenate - acetic acid, w% 5 0

Products, w% 100 100

C₄- gas w% 2.7 1.85

C₅-165.6^"C naphtha w% 5.4 4.3

165.6-315.6^"C gas oil w% 13.7 14.78

315.6^"C⁺ bottoms w% 78.2 79.7

Viscosity of 315.6^"C⁺ bottoms at 50^"C 246 2147 cutter stock required to make 120 cSt heavy fuel oil w% 8 26 cutter stock reduction w% 18 base

Table 14 shows that an increase in visbreaking severity in the presence of 5 w % the organic oxygenate resulted into a considerable savings in the cutter stock required to manufacture 120 cSt (50 °C) fuel oil product. By visbreaking at 800 ERT seconds in the presence of 5 w% the organic oxygenate, 18 w% reduction in cutter stock requirement is achieved, in comparison to conventional visbreaking at 500 ERT seconds.

EXAMPLE 5

The example used a vacuum residuum of Arabian light stocks and a low temperature coal tar of which physical properties were as set out in table 15 and table 16 below respectively:

Table 15

Physical properties of the vacuum residuum of Arabian lij »ht stock

Nominal initial boiling point, ^'C 445

Viscosity, cSt at

54.4^"C 30,000

98.9^"C 900

Pour point, ^'C 36

API 7.1

Aromatics sulfur content, weight % 4.0

Conradson Carbon Residue (CCR), weight % 20.3 Table 16

The admixture of the vacuum residuum of Arabian light stock and the coal tar with the following mixing ratio was visbroken at 800 ERT seconds at 427 °C (800^' F). After visbreaking, cutter stock shown in table 8 was added to reduce viscosity to meet product specifications. Accordingly, the viscosity, pour point and sedimentation results were reported in Table 17 below respectively. The viscosity and pour point tests were conducted before the cutter stock was added and the sedimentation test afterwards. The sediment test used, as described in example 1, was the centrifuge method used to determine the compatibility of sediment in blended fuel oil. This method is used to determine the volume percentage of incompatible sediment in blended fuel oils.

COMPARATIVE EXAMPLE 5

The vacuum residuum of Arabian light stock and the coal tar was visbroken at 800 ERT seconds at 427 °C (800^' F) respectively. After visbreaking, The admixture of the visbroken vacuum residuum of Arabian light stock and the visbroken coal tar with the mixing ratio as same as in the example 5 was prepared, then cutter stock shown in table 8 was added to reduce viscosity to meet product specifications. Accordingly, the viscosity, pour point and sedimentation results of the admixture were reported in Table 18 below respectively. The viscosity, pour point and sediment test were the same as in the example 5.

Table 17

Viscosity, cSt at Pour Point Added cutter Sediment

Mixing ratio 54.4 ^"C at ^"C stock w % Volume %

10 w% coal tar + 90 w% 331 -1 10 trace vacuum residuum

30 w% coal tar + 70 w% 237 -3 10 0.14 vacuum residuum

Example

70 w% coal tar + 30 w% 179 -6 10 0.81 5

vacuum residuum

90 w% coal tar + 10 w% 151 -10 10 2.64 vacuum residuum

100 w% vacuum residuum 2085 11 10 3.25

10 w% coal tar + 90 w% 427 7 10 2.97 vacuum residuum

comparative

30 w% coal tar + 70 w% 276 2 10 3.04

Example

vacuum residuum

5

70 w% coal tar + 30 w% 201 1 10 3.37 vacuum residuum

10 w% coal tar + 90 w% 174 -1 10 3.68 vacuum residuum

100 w% coal tar 141 -2 10 1.59

The yields of distillates from visbroken product were shown in the table 18 below. The used distillation method was any method well known to those skilled in the art. For simplicity, no detailed information is provided herein, that could be taken from any prior reference documents.

Table 18

Distillates yield volume%

Example 5 C₄- gas C₅-165.6^"C 165.6-315.6V 315.6^"C⁺ Bottom

10 w% coal tar + 90 w% vacuum residuum 1.58 4.78 15.1 78.5

30 w% coal tar +70 w% vacuum residuum 1.52 4.60 19.27 74.6

70 w% coal tar + 30 w% vacuum residuum 1.39 4.21 27.71 68.08

90 w% coal tar + 10 w% vacuum residuum 1.33 4.03 32.1 62.54 Comparative Example 5 C₄- gas C₅-165.6^"C 165.6-315.6V 315.6^"C⁺ Bottom

100 w% vacuum residuum 1.58 4.78 12.76 80.88

10 w% coal tar + 90 w% vacuum residuum 1.55 4.68 14.79 78.98

30 w% coal tar +70 w% vacuum residuum 1.48 4.48 18.8 75.24

70 w% coal tar + 30 w% vacuum residuum 1.35 4.09 26.9 67.66

90 w% coal tar + 10 w% vacuum residuum 1.28 3.89 31.0 63.83

100 w% coal tar 1.25 3.79 33.01 61.95

It is obviously seen from comparison between tables 17 and 18 that the benefits of adding the admixture of the vacuum residuum of Arabian light stock and the coal tar as feed to the visbreaker are evident. The viscosity has been significantly reduced by co- visbreaking to the vacuum residuum of Arabian light stock and the coal tar.

The pour point of the product has been significantly reduced also by co- visbreaking to the vacuum residuum of Arabian light stock and the coal tar. The visbroken product of the invention had only an acceptable amount of sediment. In contrast, the visbroken product obtained by mixing of the vacuum residuum of Arabian light stock and the coal tar after visbreaking approximately produced 3-4 % sediment by addition of 10 w% cutter stock.

In the same way, as also obviously seen from tables 17 and 18, the yield of distillates from visbroken product according to the present invention is enhanced by 2-4 w% in comparison with results that was not derived from co- visbreaking.

EXAMPLE 6 The example used a reduced crude of Arabian light stocks and a low temperature bio oil of which physical properties were as set out in table 19 and table 20 below respectively:

Table 19

Physical properties of the reduced crude of Arabian light stock

Nominal initial boiling point, ^'C 416

Viscosity, cSt at

54.4^"C 150

98.9^"C 25

Pour point, ^'C -9

API 15.9

Aromatics sulfur content, weight % 3.3

Conradson Carbon Residue (CCR), weig ht % 8.5

Table 20

Physical properties of the bio oil obtained by fast pyrolysis of log leftover bits and pieces at 450^'C

API Water w% Ash w% Viscosity, cSt at 50^'C CCR w%

-0.48 22 8.3 86.9 4.7

Elements analysis of the bio oil, w%

C H O N S HVC ratio

58.1 6.2 35.6 0.1 0 1.28 The admixture of the reduced crude of Arabian light stock and the bio oil with the following mixing ratio was visbroken at 800 ERT seconds at 427 °C (800^' F). The viscosity and pour point results of visbroken product were reported in Table 21 below respectively.

COMPARATIVE EXAMPLE 6

The reduced crude of Arabian light stock and the bio oil were visbroken at 800 ERT seconds at 427 °C (800^' F) respectively. After visbreaking, the admixture of the visbroken reduced crude of Arabian light stock and the visbroken bio oil with the mixing ratio as same as in the example 6 was prepared. Accordingly, the viscosity and pour point of the admixture were also reported in Table 21 below respectively. The viscosity and pour point tests were the same as in the example 6.

Table 21

Viscosity, cSt at 54.4^'C Pour Point at ^'C

Mixing ratio

5 w% bio oil + 95 w% reduced 59 -19 crude

Example

10 w% bio oil + 90 w% reduced 50 -21 6

crude

100 w% reduced crude 91 -13 comparative 5 w% bio oil + 95 w% reduced 74 -16 crude

Example

10 w% bio oil + 90 w% reduced 61 -19 6

crude

It is obviously seen from the above table 21 that the benefits of adding the admixture of the reduced crude of Arabian light stock and the bio oil as feed to the visbreaker are evident. Not only has the viscosity but also the pour point of the product been reduced by co- visbreaking to the reduced crude of Arabian light stock and the bio oil.

EXAMPLE 7

The example used the vacuum residuum of Arabian light stocks shown in above table 15 and a pyrolytic vapor, obtained by pyrolysis of coal from Hullender, Inter Mongolia at 550 °C , which of physical properties were as set out in table 22 below:

Table 22

Coal pyrolytic products composition w%

Semi coke Coal tar Pyrolysis gas water Total amount

56.72 8.83 6.66 27.37 99.58

Pyrolytic vapor composition after dehydration w%

Gaseous coal tar : 57 Pyrolysis gas: 43

Pyrolysis gas composition w% o₂ N₂ C¾ CO co₂ C2H4 C2H total

0.4 0.53 28.93 12.52 38.46 0.76 2.24 16.16 100

The physical properties of the coal tar shown in the above table 22 has been reported in the table 16. The admixture of the vacuum residuum of Arabian light stock shown in above table 15 and the above pyrolytic vapor with the following mixing ratio was visbroken at 800 ERT seconds at 427 °C (800^' F). After visbreaking, cutter stock shown in table 8 was added to reduce viscosity to meet product specifications. Accordingly, the viscosity, pour point and sedimentation results were reported in Table 23 below respectively. The viscosity and pour point tests were conducted before the cutter stock was added and the sedimentation test afterwards. The sediment test used, as described in example 1, was the centrifuge method used to determine the compatibility of sediment in blended fuel oil. This method is used to determine the volume percentage of incompatible sediment in blended fuel oils.

COMPARATIVE EXAMPLE 7

The vacuum residuum of Arabian light stock and the above pyrolytic vapor were visbroken at 800 ERT seconds at 427 °C (800^' F) respectively. After visbreaking, the admixture of the visbroken vacuum residuum of Arabian light stock and the visbroken pyrolytic vapor with the mixing ratio as same as in the example 7 was prepared, then cutter stock shown in table 8 was added to reduce viscosity to meet product specifications. Accordingly, the viscosity, pour point and sedimentation results of the admixture were reported in Table 23 below respectively. The viscosity, pour point and sediment test were the same as in the example 7.

Table 23

Viscosity, cSt at Pour Point Added cutter Sediment

Mixing ratio 54.4 ^"C at ^"C stock w % Volume %

10 w% pyrolytic vapor + 515.9 5 10 trace 90 w% vacuum residuum

Example

20 w% pyrolytic vapor + 267.8 -2 10 trace 7

80 w% vacuum residuum 100 w% vacuum residuum 2085 11 10 3.25

10 w% pyrolytic vapor + 761.4 8 10 3.41 comparative

90 w% vacuum residuum

Example

20 w% pyrolytic vapor + 398 4 10 3.26

5

80 w% vacuum residuum

100 w% pyrolytic vapor 111 -4 10 trace

It is obviously seen from the above table 23 that the benefits of adding the admixture of the vacuum residuum of Arabian light stock and the coal pyrolytic vapor as feed to the visbreaker are evident. The viscosity of visbroken product has been significantly reduced by co- visbreaking to the vacuum residuum of Arabian light stock and the coal pyrolytic vapor.

The pour point of the product has been significantly reduced also by co- visbreaking to the vacuum residuum of Arabian light stock and the coal pyrolytic vapor. The visbroken product of the invention had only an acceptable amount of sediment. In contrast, the visbroken product obtained by mixing of the vacuum residuum of Arabian light stock and the coal pyrolytic vapor after visbreaking approximately produced 3.2-3.4 % sediment by addition of 10 w% cutter stock.

Because the above coal pyrolytic vapor contained a certain amount of hydrogen gas as shown in the table 22, during visbreaking of coal pyrolytic vapor as well as co-visbreaking of the vacuum residuum of Arabian light stock and the coal pyrolytic vapor, hydrogenation reaction partially took place. Such effect also contributed to viscosity reduction of the visbroken product. Although a few embodiments of the present invention have been shown and described, the present invention is not limited to the described embodiments. Instead, it would be appreciated by those skilled in the art that any changes and modification may be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

Claims:

1. An improver for visbreaking processing to heavy oils and/or similar carbonaceous materials comprising: at least one organic oxygen functional group.

2. The improver according to claim 1, wherein the organic oxygen functional group includes [-CO-] and/or [-0-] radical.

3. The improver according to claim 2, wherein the organic oxygen functional group are carbonyl group [-C(O)-]; ether group [R-O-R']; aldehyde group [-CHO]; ketone group [R-C(0)-R']; hydroxyl group [-OH]; quinine group [C₆H₄O₂] ; furan group [C₄H₄O]; any substituted derivative of furan and quinine; and/or mixture thereof , wherein R and R' independently are alkyl radicals or other organic groups respectively.

4. The improver according to claim 3, wherein the improver is

3- hydroxy-4-methoxy-phenol, furan, quinine, 4-hydroxy-3-methoxy-phenol,

2.5- dimethoxybenzyl alcohols, (l,l-dimethylethyl)-l,2-benzenediol, C₁-C₂ substituted benzofuran, methanol, l-(4-hydroxy-3-methoxyphenyl)ethanone, hydroxyl-propanone, 3,4-dimethoxyphenol,

3,

4-dimethoxybenzoic acids, 2-methoxy-4-ethylphenol, multi-substituted benzofuran, ethanediol, 2,6-dimethoxy-4-(2-propenyl)-phenol, 2-methoxy-dibenzofuran, 2,3-diacetyl, 1 -hydroxyl- aldehyde, propanoldiacid, and any substituted derivative and /or mixture thereof.

5. The improver according to claim 1, wherein the improver is at least one component as organic oxygenate existing coal tar and /or bio oil.

6. The improver according to claim 1, wherein the heavy oils have API Gravity (American Petroleum Institute Gravity) of less than 22.3.

7. The improver according to claim 6, wherein the heavy oils further have API Gravity of less than 16.

8. The improver according to claim 1 or 6, wherein the heavy oil is at least one component selected from group consisting of residual fractions obtained by catalytic cracking of gas oils, solvent extracts obtained during the processing of lube oil stocks, asphalt precipitates obtained from deasphalting operations, high boiling bottoms or residuum obtained during vacuum distillation of petroleum oils, tar sand, bitumen, vacuum pipestill bottoms, crude oil, reduced crude, vacuum residuum, heavy residual oil, coal liquefaction residue or oil recovered from tar sands.

9. The improver according to claim 1 or 6, wherein the heavy oils do or do not derive from petroleum.

10. The improver according to claim 1, wherein the similar carbonaceous materials include coal tar and/or bio oil.

11. The improver according to claim 5 or 10, wherein the coal tar or bio oil is one produced by rapid and medium & low temperature pyrolysis of coals or bio substances.

12. The improver according to claim 11, wherein the rapid and medium & low temperature pyrolysis of coals or bio substances is meant that the coals or bio substances is pyrolyzed under temperature of more than 450 °C but less than 750 °C within time of less than 45 minutes.

13. The improver according to claim 1 or 10, wherein the similar carbonaceous materials include mixture of coal tar or bio oil and the heavy oils or mixture of coal tar, bio oil and the heavy oils.

14. The improver according to claim 1, wherein the improver is used in amount of 0.1-50%, based on weight of oxygen therein, by weight of the heavy oils and/or similar carbonaceous materials.

15. The improver according to claim 14, wherein the improver is further used in amount of 0.5-30%, based on weight of oxygen therein, by weight of the heavy oils and/or similar carbonaceous materials.

16. A process for visbreaking heavy oil and/or similar carbonaceous materials, comprising: the heavy oil and/or similar carbonaceous materials is subjected to visbreaking in the presence of the improver according to any one of aforesaid claims 1-15, which is used in amount of about 0.1-50 %, based on weight of oxygen therein, by weight of the heavy oils and/or similar carbonaceous materials.

17. A process for co-visbreaking to coal tar and/or bio-oil containing the improver according to any one of aforesaid claims 1-15 and heavy oil and/or similar carbonaceous materials, comprising: a mixture of the coal tar and/or bio-oil and heavy oil and/or the similar carbonaceous materials is subjected to visbreaking, mixing ratio of which is total weight of the coal tar and bio-oil/total weight of heavy oil and/or the similar carbonaceous materials of 1/99 - 99/1.

18. The process according to claim 17, wherein the total weight of the coal tar and bio-oil/ the total weight of heavy oil and/or the similar carbonaceous materials further is 10/90 - 90/10.

19. The process according to claim 18, wherein the total weight of the coal tar and bio-oil/ the total weight of heavy oil and/or the similar carbonaceous materials further is 30/70 - 70/30.

20. The process according to any one of aforesaid claims 17-19, wherein the coal tar or bio-oil is not used while the heavy oil or similar carbonaceous materials is also not used.

21. The process according to any one of aforesaid claims 16-19, wherein visbreaking operation severity is in range of 400 - 1000 equivalent reaction time

(ERT) seconds at 427 ^°C ( 800^° F).

22. The process according to claim 21, wherein the visbreaking operation severity is further in range of 600 - 800 equivalent reaction time (ERT) seconds at

427^°C ( 800^° F).

23. The process according to any one of aforesaid claims 16-19, wherein the visbreaking is carried out at a temperature from 375 ^°C to 515^°C with a residence time of 1 to 60 minutes under 0. 45 - 7 MPa.

24. The process according to claim 23, wherein the visbreaking is further carried out at a temperature from 425 ^°C to 485 ^°C with a residence time of 1 to 30 minutes under 1.5 - 5 MPa.

25. The process according to any one of aforesaid claims 16-19, wherein the visbreaking is any one of normal visbreaking, catalytic visbreaking, hydro visbreaking, hydrogen donor visbreaking.

26. The process according to any one of aforesaid claims 16-19, wherein the heavy oil is non- petroleum oil.

27. A process for co-visbreaking to coal and/or bio-substance pyrolytic vapor containing the improver according to any one of aforesaid claims 1-15 and heavy oil and/or similar carbonaceous materials, comprising: a mixture of the coal and/or bio- substance pyrolytic vapor and heavy oil and/or the similar carbonaceous materials is subjected to visbreaking, mixing ratio of which is total weight of the coal and/or bio- substance pyrolytic vapor /total weight of heavy oil and/or the similar carbonaceous materials of 1/99 - 99/1.

28. An application of an organic oxygenates including organic oxygen functional group containing [-CO-] and/or [-0-] radical as an improver for visbreaking processing to heavy oils and/or similar carbonaceous materials.