Method of and apparatus for granulating precipitates from petroleum processing processes

(12) PATENT DESCRIPTION (19) PL (11) 196460 (13) B1 (21) Application number: 344118 ^{(51) Int.Cl.}

B01J 2/06 (2006.01) C10C 3/16 (2006.01) C10L 5/00 (2006.01) (22) Date of notification: 23/11/2000

Method and device for granulating sludge from crude oil processing processes and sludge granules from crude oil processing processes

<td>(30) Priority: 1999-11-23, US, 447,408</td><td>(73) The right holder of the patent: KELLOGG BROWN &amp; ROOT INC., Houston, US</td>

<td>(43) Application announced: June 4, 2001 BUP 12/01</td><td>(72) Inventor (s): Jon C. Moretta, Houston, US Murugesan Subramanian, Houston, US</td>

<td>(45) The grant of the patent was announced: 31.01.2008 WUP 01/08</td><td>(74) Representative: Lukaszyk Szymon, Łukaszyk Patent Office</td>

₍₅₇₎ 1. A method of pelletizing sludge from petroleum processing processes, characterized in that the sludge is heated to a temperature where it is liquid and continuously delivers hot sludge to the inlet of a centrifugal granulation head having a plurality of radially arranged outlets; the granulating head is rotated to release hot sludge from the openings into a free space at the higher end of the granulation chamber having a larger diameter than the diameter of discharged sludge ejection; then separating and forming spherical granules from the discharged sludge in the high temperature zone of the granulation chamber, in which the sludge in a liquid state falls down into a bath in a liquid cooling medium kept at a temperature sufficient for the granules to solidify into an almost spherical form; and then the slurry of coagulated granules and cooling agent is drawn from the granulation chamber and the granules are separated from the cooling agent.

21. The sediment granules, characterized by being spherical, compositionally homogeneous and combustible, having a size of between 0.1 to 10 mm, a penetration substantially equal to 0, a softening point of about 93.4 ° C (200 ° F) to about 204.5 ° C (400 ° F), and a residual water content of 0.1 to 10 wt.%. and a sulfur content of less than 10 wt.%.

23. Apparatus for granulating sludge from petroleum processing processes from a substantially solid feed material that can be melted at elevated temperature, characterized in that it comprises a vertical granulation chamber (36) having an upper granulating zone and a zone forming spherical granules downstream of the granulating zone , a cooling zone below the ball-forming zone, and a lower cooling bath (52) below the cooling zone; and a centrally advanced granulation head (46) in the zone ............................

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PL 196 460 B1

Description of the invention

The subject of the invention is a method and a device for granulating sludge from petroleum processing processes, in which the sludge is melt granulated by means of a rotary granulation head so that the liquid sludge particles produced by this granulation head are formed into spheres before the solidification process takes place. and then quenched and solidified to a substantially spherical shape. The invention also relates to pellets of sludge from petroleum processing processes that can be stored and / or transported at ambient temperature. The invention is also intended to cure relatively soft sludge from petroleum processing processes by controlled air oxidation at elevated temperatures to form hard petroleum by-products that can be granulated and stored or transported at ambient temperature.

The residues from the crude oil distillation process have a wide variety of uses, including road asphalt and fuel. Road grade asphalt used in road construction must meet a number of technical requirements, including the latest SHRP parameters, dynamic viscosity coefficient (typically 200 to 5000 P at 15.55 ° C (60 ° F), penetration (typically greater than 30 to 200 dmm) ), penetration index at -9.45 / 3.89 ° C (15/25 ° F) (typically above 0.3), ductility / ductility, temperature sensitivity and more.

Contact of sludge from petroleum processing processes with air at elevated temperature, also known as "air oxidation", is a conventional way to improve the characteristics of certain sludge grades to make them suitable for use as road asphalt. However, the practical applications of air oxidation of a relatively soft sludge to obtain a relatively hard sludge that can be granulated for storage or transportation are not known. The terms that have been used in the specification and claims such as "soft sludge", "low softening point" refer to the sludge from petroleum processing processes having a penetration index above 0 and having a softening point below 93.33 ° C (200 ° F) as determined by ring and ball method. The terms "hard deposits" or "high softening point" refer to sludges from petroleum processing processes having a penetration index of substantially 0 and a softening point above 93.33 ° C (200 ° F) by the ring and ball method.

U.S. Patent Nos. 2,616,837 (Roediger); US 2,627,498 (Fink et al.); US 2,861,939 (Biribauer et al.); US 2,889,296 to Morris et al.; US 3,462,359 (Fauber); US 3,598,716 (Fauber); US 3,751,278 (Alexander); US 3,779,892 (Forste et al.); US 3,868,315 (Forste et al.); US 3,935,093 (Senolt et al.); US 3,989,616 (Pagen et al.); US 4,052,290 (Cushman et al.); US 4,207,117 (Espenscheid et al.); US 4,283,230 (Clementoni et al.); US 4,332,671 (Boyer); US 4,933,067 (Rankel); US 4,975,176 to Begliardi et al.; US 5,228,977 (Moran et al.); US 5,320,739 to Moran et al.; US 5,932,186 (Romine et al.); and US 5,939.47 (Gooswilligen), devices and methods for the air oxidation of asphaltenes and resins are known. Air oxidation technology is also known under the trade designation BITUROX.

Compared to road asphalt, the parameters for fuel sludge from petroleum processing are much more stringent. The sludge has a substantially higher calorific value and better combustion properties compared to coal and petroleum coke. Therefore, the sludge is added to coal and petroleum coke as a fuel additive to aid combustion. However, heavy sludge with a low softening point is difficult to store and / or transport as it does not meet the high packaging and precautionary requirements. Over time, even when initially these materials may appear solid at ambient temperature, because they have a low softening point, they exhibit plastic properties at elevated temperatures. They are usually shipped as semi-liquid products, as pure liquid products, or as a dilute liquid product. The semi-liquid form must be transported in a closed container to prevent leakage and spilling and is additionally heated before use, and the high cost of packaging and handling the material by the above-mentioned methods usually limits its use.

As a pure liquid product, the heavy precipitate is kept at an elevated temperature sufficient to support the material in liquid form. This method is also expensive and has limited practical application.

PL 196 460 B1

As a dilute liquid product, heavy sediment is mixed with light hydrocarbons to keep the mixture fluid at low temperature. As a result, the lighter hydrocarbons with which the sludge is mixed make a significant decrease in value.

The granular sludge, which remains solid, would not be liquid and could be easily stored, packed and transported. Previous efforts to pelletize the sludge at a low softening point have been to encapsulate the sludge with a solid coating. Covering the deposit with a coating leads to a compositionally heterogeneous product, increasing the cost, which is associated with generally expensive covering material, and is not always effective due to cracking or tearing of the coating or its dissolution by water (if it is soluble) . The coating may also adversely affect the burning properties of the sludge. Representative works on a variety of encapsulation devices and related methodology include US patents US 3,015,128 and US 3,310,612 (Somervill); US 4,123,206 and US 4,128,409 (Danelly); US 4,386,895 (Sodickson) and US 5,637,350 (Ross).

US 4,931,231 (Teppo et al.) Discloses a method of producing granular granules of asphalt material, which consists in flowing the asphalt material in a molten form as an elongated ring stream directly into the cooled water in order to solidify it and break the elongated stream into a solid granular particles. The particles formed as a result of disintegration, however, do not have a spherical shape and the desired plastic features and characteristics. For example, they may be dust free as soon as they are formed, but may later become dusty due to jagged edges as a result of subsequent handling.

Another US 3,877,918 (Cerbo) discloses an apparatus for producing spherical glass particles by centrifugally ejecting solid glass crushed particles into a furnace suction tube using a rotary receiver. The rotating receptacle creates a cloud of evenly dispersed solid glass particles that are directed upward into the furnace chamber to heat and spheres the glass particles by surface tension.

Previous studies do not describe methods or apparatus for producing spherical pellets of sludge from petroleum processing processes by supplying the sludge in a liquid state to the rotary granulation head, allowing the sediment to break out of the granulation head to break into particles and form into balls due to the surface tension of the sediment liquid, as a result of the gravitational passage of particles through the high temperature zone, and then cooling the liquid material in a cooling environment to fuse the particles into the most spherical form. Thus, no previously disclosed spherical, compositionally homogeneous (without coating), petroleum-derived granules having a high softening point, nor have there been disclosed methods and devices for producing granules from sludge derived from petroleum processing processes, adapted for storage and transport at ambient temperature and use in combustion processes. as a fuel or fuel additive.

According to the invention, it is possible to produce spherical granules from a material such as sludge from petroleum processing processes, which is usually solid at ambient temperature but may be liquid at elevated temperature. The invention relates to the production of a compositionally homogeneous granular sludge from petroleum processing processes suitable for storage and transportation at ambient temperature prior to its end use. The granules are relatively hard with a softening point greater than 93.33 ° C (200 ° F) and therefore do not stick together at ambient storage and transport temperatures. If the sludge - material fed to the processing device is not hard enough, it can be hardened by oxidation with air at elevated temperature. The sludge is granulated at the melting points using a rotating granulation head which directs the molten sludge into the high temperature steam space. As the sludge is ejected from the granulation head and falls by gravity, it breaks up into small pieces which, while still in a liquid state, are formed into spheres. After forming the spheres in a liquid state, the pellets are cooled and solidified, for example, by passing the spheres through a mist of water and collecting them in a water bath.

In particular, the invention relates to a method of granulating sludge from petroleum processing processes. The method consists of: (1) heating the sludge to a temperature at which it is liquid, (2) continuously supplying the molten sludge to the inlet of the granulation head, consisting of a large number of radially arranged outlets in fluid communication with the inlet, ( 3) rotating the granulation head to discharge the sludge from the outlet openings into the free

The space near the upper end of the granulation chamber, the diameter of which is greater than the diameter of the ejection of the released sediment, (4) allowing the released sediment to break into pieces and form into spherical granules in the high temperature zone of the granulation chamber, where the sediment from the treatment processes the crude oil is in a liquid state and sinks down to contact the coolant, wherein the precipitate is insoluble and which is kept at a temperature that allows the granules to cool / solidify, (5) drawing a mixture of the coagulated granules and cooling agent from the granulation chamber, and (6) separating the granules from the cooling agent.

The outlet openings in the granulation head are preferably arranged around the circumference of the granulation head such that they form a vertically arranged plurality of upper and lower rows. It is preferred that the lower row or rows are distributed such that their diameter, centered on the axis of rotation of the granulation head, is smaller than the diameter of the upper row or rows. The best circumference of the granulation head is one that is tapered from the uppermost to the lowest row of outlets. The granulating head can be rotated at a speed of about 10 to about 5000 rpm. The best diameter for the granulation head is from about 5 to about 155 cm (about 2 inches to about 5 feet) in length, and for the inlet openings, from about 0.07 to about 2.54 cm (1/32 to about 1 inch) in length. In contrast, the production capacity per outlet is in the order of about 0.454 kg (1 lb) to about 453.592 kg (1000 lb) per hour. The ejection axis is from about 30 to about 450 cm (1 to about 15 feet) and the pellet size range is from 0.1 to about 10 mm.

Preferably, the cooling medium is water and the water bath is kept at a temperature of from about 4.44 to about 87.78 ° C (from 40 to about 190 ° F). Preferably, the water is introduced into the granulation chamber as an internally directed spray jet, for example in the form of a fine mist, into the cooling zone above the bath to cool the spherical granules at least partially before entering the bath. The slurry drawn from the pelletizing chamber should be no more than 10 ° C (50 ° F) warmer than the water introduced into the cooling zone. The method of the invention may also include collecting water during separation, and filtering, cooling, and recycle chilled water for use in the quench zone.

The method of the invention may also include vapor suction near the top end of the granulation chamber and / or heating the top end of the granulation chamber to maintain a largely constant temperature zone near the granulation head. The above method may further consist of transporting the recovered pellets at ambient temperature to a location remote from the pelleting chamber where the pellets are used for combustion, as a combustion enhancing additive or as an additive to coke and / or coal, in admixture with fuel, or the like.

The sludge from the petroleum refining process that has been subjected to the reheat operation should have a penetration factor of nearly 0 and a softening point of about 93.3 to about 204.4 ° C (200 to about 400 ° F), and preferably a softening point of about 110 to about 176.7 ° C (230 to about 350 ° F). Ideally, the sludge should be obtained from the solvent deasphalting process as an asphaltene rich fraction. The sludge is heated to a temperature of about 176.7 to about 371.1 ° C (about 350 to about 700 ° F), while the granules recovered from the separation process may contain residual amounts of water from about 0.1 to about 10% by weight. The sludge pellets obtained by the process of the invention can serve, for example, as a combustion fuel, or as an additive in the combustion of coal and / or petroleum coke, or as a blend component in fuel oil.

The process of the invention also involves bringing the soft sediment into contact with air at a temperature of from about 176.7 to about 371.1 ° C (350 to about 700 ° F) for a period of time sufficient to reduce the sediment penetration rate to nearly 0 and increase the softening point to above 93.3 ° C. (200 ° F) to form a hard deposit suitable for use as a ready-to-pellet deposit. The soft sludge can be obtained from the atmospheric column, or as an asphaltene-rich fraction from the solvent deasphaltization of petroleum residues. This operation should take from about 2 to about 5 hours.

In another aspect of the invention, there is provided a process for making sludge pellets from soft sludge from petroleum processing processes. This process involves contacting a soft sediment with a penetration greater than 0 and a softening point less than about 93.3 ° C (about 200 ° F) with air at a temperature of about 176.7 ° C to about 371.1 ° C (350 to about 700 ° F) at for a period of time sufficient for the formation of a hard deposit with a penetration substantially equal to 0 and a temperature

For softening above 93.3 ° C (200 ° F) and forming a hard deposit in the granule. The granules are used for combustion, for example as a fuel or a fuel additive.

The invention also includes a granulating device for producing spherical granules from a material such as a sludge from petroleum processing processes, which typically exhibits solid properties but can nevertheless be liquefied at elevated temperatures. The granulating apparatus comprises: a vertical granulation chamber having an upper granulating zone, a hot ball-forming zone below the granulating zone, a cooling zone below the ball-forming zone, and a lower cooling bath below the cooling zone. The granulating head, which is centrally located in the granulating zone, can rotate along a vertical axis. The granulating head has a plurality of outlets for spreading the molten feed radially outward. The ejection diameter of the granulation head is smaller than the inside diameter of the granulation chamber. In the method according to the invention, the processing line provides the granulation head with material to be granulated. The vertical height of the ball forming zone is sufficient to allow the flowable material to be expelled from the granulation head to form into spherical granules while still in a liquid state. The nozzles are provided to spray a liquid cooling medium, preferably water in the form of a mist, internally into the cooling zone to cool and solidify at least the outer shell of the granules so that they can be collected in a water bath. Another line is introduced for supplying water to the nozzles and the water bath in order to keep the bath temperature relatively low in the granulation chamber. Another line is introduced for drawing the granule suspension in a water bath. The liquid-solid separator is designed to dewater the granules from the suspension.

The granulating apparatus may also include an oxidizing vessel to contact a soft sediment, having a penetration greater than 0 and less than 100 dmm, with air at a temperature of about 176.7 to about 371.1 ° C (about 350 to about 700 ° F) for a time sufficient to reduce the temperature. penetrating the sludge to a level close to 0 and increasing the softening point to above 93.3 ° C (200 ° F) to form a hard deposit suitable for feeding into the granulation head. It is preferred that the granulating apparatus additionally comprises a unit deasphalting system for obtaining a soft sludge as an asphaltene fraction from the solvent deasphalting sludge of petroleum processing processes.

The inlet openings of the granulation head should be positioned at the periphery of the granulation head in a plurality of vertically positioned top and bottom rows with the bottom row or rows spaced smaller in diameter from the axis of rotation of the granulation head than the higher ranks or row. The granulating head may have a constricted circumference, either continuously or gradually, from the uppermost row with a relatively large diameter to the lowest row with a relatively small diameter. In one possible version, the granulating head consists of a plurality of rings of different diameter with holes formed in the inner circumference of each ring, where the rings are attached to the granulation head in the discharging finish, and each successively lower ring has a smaller diameter than the preceding ring. The granulating apparatus includes a drive to rotate the granulation head at a speed of from about 10 to about 5000 rpm, where the granulation head is from about 5 to about 150 cm (about 2 inches to about 5 feet) in diameter, and where the orifices have a diameter from about 0.07 to about 2.54 cm (1/32 to about 1 inch), and the production rate is from about 0.454 to about 453.592 kg / h (1-1000 lb / hr) of molten material per hole.

It is preferred that the cooling medium is water and the granulating apparatus includes a cooler needed to maintain the bath in the granulation chamber at a temperature of from about 4.44 ° C (40 ° F) to about 87.8 ° C (190 ° F). The water bath contains a small amount of non-foaming surfactant. It is preferred that the chamber has a conical bottom containing a bath and an outflow at the lower end of the conical bottom which serves to bring the slurry to the drainage line. A filter is inserted to filter the water recovered from the liquid-solid separator, a cooler is provided to cool the filtered water, and a recirculation line is provided to recycle chilled water to the supply line.

Preferably, the ventilation portion is introduced to extract steam close to the upper end of the granulation chamber. A heater may also be provided here to heat the upper part of the chamber in order to maintain a constant temperature in the zone adjacent to the granulation head, which is particularly important during the initial operations of the method of the invention. In one preferred embodiment, a line is provided for introducing steam into the sphere forming zone.

PL 196 460 B1

The liquid-solid separator consists of a vibrating screen. The granulating equipment can also be equipped with a conveyor belt to transport the granules from the vibrating screen for storage, packaging and transportation at ambient temperature.

The method and device according to the invention allows to obtain almost spherical, homogeneous granules suitable for combustion, having a size of the order of 0.1 to 10 mm, a penetration of almost 0, a softening point of 93.3 ° C (200 ° F) to about 204.5 ° C ( 400 ° F), preferably from about 110 ° C (230 ° F) to about 176.7 ° C (350 ° F), residual amounts of water from 0.1 to 10% by weight, and a sulfur content of less than 10% by weight. The sediment granules can be a hard sediment produced by a process where the soft sediment comes into contact with air at elevated temperature for a time sufficient for the soft sediment to change to hard sediment, which typically takes 2 to 5 hours.

The subject of the invention is presented in more detail in the example of the drawing, in which Fig. 1 shows a simplified technological flow diagram of the hard sludge granulation method from the crude oil processing processes according to the invention, Fig. 2 shows a simplified technological flow diagram of the process alternative to the method shown in Fig. 1, which consists in the oxidation of soft sludge from petroleum processing processes to convert it to hard sludge prior to granulation, Fig. 3 is a simplified flow diagram of the granulating device according to the invention, Fig. 4 is a simplified diagram of the granulation head according to the invention, and Fig. 5 is simplified diagram of the granulating head of one alternative to this invention.

The sludges from the petroleum processing processes that are suitable for the granulation according to the invention contain material rich in asphaltenes, in particular asphaltene particles derived from solvent deasphalting with propane or other solvent, according to the technologies used, commercially available under the trade markings: ROSE, DEMEX, SOLVAHL, and others. The term "sediment" resid), as used in the description and claims, also refers to products derived from the processing of crude oil, such as e.g. sludge from the bottom of pressure towers, sludges from the bottom of vacuum towers, rough crack residue, thermal cracking residue, soak furnace residues, residues from destructive hydrogenation, and others. The sediment may have a softening point of -17.8 ° C (0 ° F) to 204.5 ° C (400 ° F), a penetration of 0 to 100 dmm, and a sulfur content of 0 to 10 percent by weight. The sludge from propane deasphalting and from the bottom of the water tower typically has a softening point below 93.3 ° C (200 ° F).

Examples of sludges from crude oil processing processes and their properties are presented in Table 1.

Table No. 1

<td rowspan="6">SETTLEMENTS Asphaltene</td><td>SOURCE OR WAY</td><td>TEMP. SOUNDS ° C (° F)</td><td>PENETRATION (dmm)</td><td>SLAR CONTENT (wt.%)</td>

<td>solvent based deasphalting</td><td>-17.8-204.5 ° C (0-400 ° F)</td><td> 0-100</td><td> 0-10</td>

<td>propane deasphalting</td><td>-17.8-105.6 ° C (0-222 ° F)</td><td> 0-100</td><td> 0-10</td>

<td>ROSE process</td><td>-17.8-204.5 ° C (0-400 ° F)</td><td> 0-100</td><td> 0-10</td>

<td>DEMIX process</td><td>-17.8-204.5 ° C (0-400 ° F)</td><td> 0-100</td><td> 0-10</td>

<td>SOLVAHL process</td><td>-17.8-204.5 ° C (0-400 ° F)</td><td> 0-100</td><td> 0-10</td>

<td>Atmospheric</td><td>atmospheric tower</td><td>-17.8-93.3 ° C (0-200 ° F)</td><td> 0-100</td><td> 0-10</td>

<td>Cracking preliminary</td><td>preliminary cracking</td><td>-17.8-204.5 ° C (0-400 ° F)</td><td> 0-100</td><td> 0-10</td>

<td>Vacuum</td><td>pressure tower</td><td>-17.8-204.5 ° C (0-400 ° F)</td><td> 0-100</td><td> 0-10</td>

<td rowspan="3">Thermal/ / catalytic</td><td>thermal cracking</td><td>-17.8-204.5 ° C (0-400 ° F)</td><td> 0-100</td><td> 0-10</td>

<td>soaking furnace</td><td>-17.8-204.5 ° C (0-400 ° F)</td><td> 0-100</td><td> 0-10</td>

<td>hydrotreater</td><td>-17.8-204.5 ° C (0-400 ° F)</td><td> 0-100</td><td> 0-10</td>

PL 196 460 B1

Sludge from petroleum processing processes can be divided into two groups: soft and hard deposits, which are distinguished by their softening points (measured using the ring and ball method), according to ASTM (American Society for Testing and Materials) calculation No. D3461- 85, and by their penetration index according to ASTM No. D5. The ring and ball softening point for soft sediments is typically below 93.3 ° C (200 ° F) and the penetration is greater than 0. However, hard sediments have a ring and ball softening point (PiK) of approximately 93.3 ° C ( 200 ° F) or higher, and the penetration is nearly 0. The ring-and-ball softening point for sludge from petroleum processing is defined as the temperature at which the sludge has a viscosity of approximately 1,000,000 cSt and a solid to semi-solid phase transition occurs. Granules produced from soft sludge may stick together and may not show sufficient properties for efficient storage at ambient temperature. Therefore, granulation which uses a soft sludge is commercially useless unless the sludge is previously chemically modified (by oxidation with air or other suitable process) or the granules are subjected to a moisture tight coating. In contrast, granules produced from hard sediment initially, without prior processing, exhibit suitable storage or transport properties.

According to the invention, soft sediments are first oxidized by air in an oxidizing reactor which is moderate pressure (less than 345 kPa (50 psig = pounds per square inch)) and moderate temperature 176.7 to 371.1 ° C (350 to 700 ° F). ). The sludge hardens as a result of constant temperature oxidation and constant airflow per unit weight of the sludge for a period of 2 to 5 hours. By increasing the temperature and / or air flow per unit weight of the sludge, the oxidation time can be reduced. Some of the resins present in the soft sediment are oxidized and transformed into asphaltenes. Some of the resins and asphaltenes are converted into light hydrocarbons, light hydrocarbon liquids and waste gases (containing carbon monoxide, carbon dioxide, gaseous hydrocarbons and H2). The oxidation process generally reduces the heating properties of the sludge, but increases the softening point (PiK) and the oxygen content of the sludge. Oxidized sludge with a softening point above 93.3 ° C (200 ° F) is suitable for the granulation process.

The invention includes a process for producing granules or granules from both soft and hard sludge. In accordance with one embodiment of this invention, the hard deposit 10 having an initial softening point above 93.3 ° C (200 ° F) may be directly granulated, i.e. without prior preparation (see Fig. 1). Soft sludge 12 is oxidized with air or puffed 14 at elevated temperature and moderate pressure to convert it to a hardened sludge with a softening point of 93.3 ° C (200 ° F) or higher to accommodate pelletization (Fig. 2) . Granulation of both the hard and cured soft sludge is performed during the granulation operation 16 using a rotary granulator. This device has high granulating properties, flexibility to produce granules of various sizes and various deposits, ease of use, self-cleaning ability, and easy to start and stop.

The granulation process 16 produces granules which have an almost spherical shape and good fuel properties and characteristics that allow them to be easily stored and transported. The granules from the granulation process 16 can be shipped to a warehouse (Fig. 1) on a pallet or in a silo, tank or barrel, or the storage can be packed in bags, containers, barrels, and the like.

The granules can then be transported by car, train, ship or barge and the like. The granules can also be stored after transport (see Fig. 2). Preferably, they are then incinerated in conventional incineration equipment 22 designed to incinerate the sludge to obtain exhaust gas 24 from which heat is typically extracted. The invention is not only limited to the incineration of granules, it may also have other applications.

As shown in Fig. 3, hard sludge 10, (or hardened soft sludge from an oxidation device or others that may produce hardened soft sludge) is fed to the surge tank 30 drum. The surge tank 30 is designed to remove residual solvent contained in the sludge (e.g. .from asphaltenes recovered from solvent deasphalting process), which is suctioned by the top of line 32, also providing a positive suction lift for the pump

Displacement 34. The positive displacement pump 34 supplies the sludge to the granulation chamber 36 at the appropriate flow rate. The tapping apparatus, including a pressure control valve 38 and a return line 40, maintains sludge levels in the surge tank 30 and also adapts to fluctuations in the production of the granules. The sludge from the positive displacement pump passes through the cutting furnace 42 where it is heated to the desired temperature required for the granulation process. Typical exit temperature from cutting furnace 42 ranges from about 176.7 ° C (350 ° F) to about 315.6 ° C (600 ° F) or 371.1 ° C (700 ° F), depending on the viscosity and softening point of the deposit.

The hot sludge flows through the line 44 to the top of the granulation chamber 36 where it passes to the rotating granulation head 46. The rotating granulation head 46 is mounted directly on the top of the granulation chamber 36 and is rotated using an electric motor 48 or other conventional propulsion device. The speed of the rotating granulation head 46 is set between 10 and 5000 rpm.

The rotary pelletizing head 46 may have a variety of shapes which may or may not include the conical basket 46a or multi-diameter head 46b shapes shown in Figures 4 and 5, respectively. The outlet openings 50 are equally spaced across the diameter of the heads 46a, 46b in one or more rows in a triangular or square pitch or other arrangement as discussed in more detail below.

The diameter of the outlet opening 50 may vary from about 0.8 to 25 mm (about 0.03 to about 1 inch) to allow adequate separation and size of the granules during production. The combination of the diameter of the rotating head 46, the speed in rpm, the size of the outlet 50 and the viscosity affects the size of the granules and the size of the distribution, the amount of sediment per hole, and the diameter of the granule ejection. As the sludge enters the rotating head 46, due to centrifugal force, the long, narrow sludge rolls are directed into the free space at the top of the granulation chamber 36. As the sediment moves outward and / or down through the granulation chamber 36 , the sediment separates into spherical granules as the surface tension forces overcome the combined forces of inertia and viscosity. The granules spiral down into the cooling water bath 52 (see Fig. 3), which should be held in the conical bottom of the granulation chamber 36. The horizontal distance between the axis of rotation of the rotating head 46 and the point where the granules stop moving horizontally from the head and begin to fall downwards is called the rejection radius. The rejection diameter, which is twice the rejection radius, should be smaller than the inside diameter of the granulation chamber 36 to prevent the granules from hitting and concentrating on the wall of the granulation chamber 36.

Steam, an electric heating coil, or other heating means 56 may be introduced into the top of the chamber of the pelletizer to keep the space near the head 46 hot while the sludge exits the rotating head 46. Heating of the space within the top of the pelletizing chamber 36 occurs primarily during start-up, but may also be used to maintain a constant steam temperature within the pelletizing chamber 36 during normal operation. If desired, steam can be introduced through line 57 to insulate the pelletizing chamber 36 during start-up instead of or in addition to the heating elements 56. The introduction of water vapor during startup can also help remove air from the granulation chamber 36, which could cause undesirable oxidation of the sludge pellets. Maintaining a constant temperature of the vapor, close to that of the sludge inlet, helps to overcome viscous forces and can help reduce the diameter of ejection and dragging of the sludge. Gases generated by hot sludge and steam from evaporated cooling water leave the top of the granulation chamber 36 through the line of the vent 58 and are collected or burned as needed.

The granules spiral downward into a cooling water bath 52 held in the lower part of the granulation chamber 36. The water mist generated by the water nozzle 60 provides an immediate cooling and hardening of the surface of the granules, which may still have a molten core in this phase. The surface-cooled granules fall into the water bath 52. There, the water enters the lower part of the granulation chamber 36 providing turbulent motion to assist in removing the granules from the granulation chamber 36 as well as further cooling the granules. Low levels (less than 20 ppm [parts per million]) of one or more non-foaming surfactants from various manufacturers, including, but not limited to, those available under the trade designation of TERGITOL and TRITON, may be used in the cooling water to facilitate the soft landing of the granules which prevents the flattening of the spherical granules.

PL 196 460 B1

The cooling water flow rate is kept at a temperature to provide a temperature rise of from about -12.2 ° C (10 ° F) to about 10 ° C (50 ° F), or more preferably from about -9.5 ° C (15 ° F). F) to about -3.9 ° C (25 ° F) between the water supply inlet of lines 62 and 64 and the outlet line 66.

The granules and cooling water flow as slurry from the granulation chamber 36 to a separating device such as a vibrating screen 68 where the granules are dewatered. The granules may have a residual water content of up to about 10% by weight, preferably 1 or 0.1% by weight or even lower. The granules can be transported to a regular silo, an open shaft, a packaging machine or to a loading point (not shown) by means of a conveyor belt 70. Water from the dewatering screen 68 flows into the water sump 72. The water sump 72 provides a positive suction head to the cooling water pump 74. Alternatively, the water may be drawn directly to the suction pump from the dewatering screen (not shown). Cooling water is pumped back into the granulating apparatus through a solids removal member 76, for example, a filter that removes the dried product and solids. The cooling water is cooled to ambient temperature through air coolers 78, either by heat conversion with a refinery water cooling system (not shown), or by other conventional cooling means. This water is then recirculated to the granulation chamber 36 via line 80.

Typical operating conditions for the granulating apparatus of Figure 3 are shown in Table 2 below.

TABLE NO. 2 Typical operating conditions

<td>CONDITION</td><td>COMPARTMENT</td><td>RECOMMENDED RANGE</td>

<td>Temp. the sludge introduced</td><td>176.7-371.1 ° C (350-700 ° F)</td><td>204.5-315.6 ° C (400-600 ° F)</td>

<td>Pressure</td><td>1-13 atm (200 psig)</td><td>less than 3.4 atm (50 psig)</td>

<td>Head diameter</td><td>5-150 cm (2-60 inch)</td><td>5-90 cm (2-36 inches)</td>

<td>Head rotation speed</td><td>10-5000 rpm</td><td>200-3000 rpm</td>

<td>The size of the hole</td><td>0.075-2.5 cm (0.03-1 inch)</td><td>less than 1.25cm (less than 0.5 inch)</td>

<td>The cross-section of the opening</td><td>triangle or square</td><td></td>

<td>The capacity of the hole</td><td>0.454-453.592 kg / hr per hole (1-1000 lb / hr per hole)</td><td>Up to 181.4 kg / hr per hole (Up to 400 lb / hr per hole)</td>

<td>Casting Diameter</td><td>30.5-457.5 cm (1-15 feet)</td><td>61-305 cm (2-10 feet)</td>

<td>Temp. incoming cooling water</td><td>4.5-73.9 ° C (40-165 ° F)</td><td>15.6-60 ° C (60-140 ° F)</td>

<td>Temp. outgoing cooling water</td><td>21.1-87.8 ° C (70-190 ° F)</td><td>23.9-73.9 ° C (75-165 ° F)</td>

<td>Cooling water temperature difference</td><td>-12.2-10 ° C (10-50 ° F)</td><td>-9.5- -3.9 ° C (15-25 ° F)</td>

<td>Granule size (mm)</td><td>0.1-10 mm</td><td>0.5-5 mm</td>

The invention discloses the use of a centrifugal granulation head 46 to pelletize the sludge The spinning head 46 is an inexpensive, high throughput, flexible and self cleaning apparatus for pelletizing the sludge. The outlet openings 50 are arranged around the circumference of the rotating head 46. The number of holes 50 required to achieve the desired production is increased by increasing the diameter of the head 46 and / or reducing the distance between holes 50 in the same row and axially arranging the outlet holes 50 in multiple levels. The outlet openings 50 may be angularly arranged in a triangular or square configuration or other configuration.

The rotating pelletizing head 46 may have various shapes, which may or may not include the conical basket shape 46a or the multi-diameter head 46b, shown in Figures 4 and 5, respectively. The diameter of the head 46 in combination with the speed of rotation determine the centrifugal force. at which sediment is pressed out of the rotating head 46. By arranging the outlet openings 50 on different

In circumference of the head 46b, for example, it is believed that any tendency for melt / sticky granules to collide is minimized due to the fact that there are different ejection diameters in this situation, and the agglomeration of the sediment granules is inhibited before they are cooled and solidified. If so desired, different rings 47a-c in head 46b may be rotated at different speeds, for example to obtain approximately the same centrifugal force according to the circumferences.

In addition to the speed at which the head 46 rotates, its diameter, an additional operating factor is the size of the outlet 50, the sludge temperature, the ambient temperature, the size of the channels through which the sediment inside the head 46 (not shown), the viscosity and surface tension of the sediment. These variables and their ratio to granule size, production volume per opening, throw diameter, and jet break length are explained below.

The size of the outlets 50 affects the size of the granules. At a given viscosity index, rotational speed, head diameter 46 and capacity, the smaller hole 50 produces smaller granules and the larger hole produces larger granules. For the same conditions, the ejection diameter increases as the size of the holes 50 is reduced. The different size of the granules produced depends on the setting of the speed of rotation and diameter of the head 46 and the desired capacity. Depending on the desired capacity, the number of holes 50 can be determined, which may vary from 10 to 700 or more.

The centrifugal force at which the sludge can be pressed out depends on the diameter of the rotary head 46. By increasing the RPM, the pellet size decreases and the ejection diameter increases, assuming other factors are constant. Increasing the diameter of the head 46 increases the centrifugal force, and to keep the centrifugal force constant, the RPM ratio may be reduced in proportion to the square root of the proportion of the diameters of the head 46. As a rule, a higher rotational speed is required for a higher ratio of efficiency to the outlet opening 50. The typical RPM ratio ranges from 10 to 5000, while the diameter of the rotary head 46 may be from 5 cm to 150 cm (2 inches to 5 feet) in diameter.

As a rule, the sludge viscosity increases exponentially with a decrease in temperature. This coefficient at various temperatures can be calculated by an interpolation method according to ASTM techniques which are not foreign to those familiar with the subject, assuming the viscosity is known at the two temperatures. The viscosity index influences the size of the produced granules. Assuming the other factors are constant, a higher sludge viscosity results in an increase in granule size.

Example 1 and 2

The studies were conducted with two types of sludge produced by the solvent deasphalting process, which have a softening point measured by the ring and ball method of 129.5 ° C (265 ° F) and 144.5 ° C (292 ° F). The experimental apparatus consisted of a feed tank furnace, pump 34, heated feed line 44, sealants needed to transfer the sludge to the swivel head, multi-hole swivel head 46 of motor 48, and belt to actuate the head and pellet accumulation trough. The sludge was heated to the desired temperature in a drum furnace and pumped to the rotating head 46 by the pumps 44 of the granulating machine. The pump used was a gear pump capable of pumping up to 5 gpm (gallons per minute). The high temperature, moderate pressure of the sealants ensured a leak-free connection between the feed line 44 and the rotating head during sludge feeding.

The pump was calibrated before each experiment. As the sludge entered the rotating head 46, the centrifugal force disengaged long thin rolls of sludge into the void of the top of the granulation chamber 36. As the sludge fell into the gas space, it broke into spherical granules as the surface tension force overcame the combined viscous forces inertia. The granules then spiraled into a collection vessel with a cooling water bath 52.

The test head 46 used in the test was placed in a metal chamber, the gas inside the chamber was kept at a temperature approximately to the temperature of the introduced sludge by means of kerosene-ignited air heaters 56. The rotating head 46 was kept at a temperature approximately to the temperature of the introduced sludge by means of an induction heating element . The metal chamber 36 was heated to overcome the viscous forces that allowed the formation of spherical granules. This also reduced the ejection diameter and inhibited sludge drag. The test was conducted with single as well as multiple holes and the granules were produced at high efficiency. When working with multiple holes, the granules did not clump either in the gas space or as they fell into the collection vessel.

PL 196 460 B1

Examples 1 and 2 show the operation of a granulating device provided with a centrifugal ejection device which is in accordance with the essence of the invention and demonstrates the ability of this apparatus to produce granules.

The sludge properties and operational parameters are shown in Table 3 below:

Table 3

<td>PROPERTIES / PARAMETER</td><td>EXAMPLE 1</td><td>EXAMPLE 2</td>

<td colspan="3">Properties of the sediment</td>

<td>softening point ° C (° F)</td><td>129.5 ° C (265 ° F)</td><td>144.5 ° C (292 ° F)</td>

<td>sulfur (wt.%)</td><td> 1.7</td><td> 4.1</td>

<td>storage test up to 83 ° C (150 ° F) with axial load</td><td>passed</td><td>passed</td>

<td>brittleness test, backing material (wt%)</td><td>&lt;2 wt.%</td><td>&lt;2 wt.%</td>

<td>net heat of combustion (kJ / kg), (Btu / lb)</td><td>39,303 kJ / kg (16,900 Btu / lb)</td><td>38,907 kJ / kg (16,730 Btu / lb)</td>

<td>granule size (mm)</td><td>0.5 to 3</td><td>0.5 to 3</td>

<td colspan="3">Operational parameters</td>

<td>centrifugal head diameter in cm (inch)</td><td>6 cm (2.4 inches)</td><td>6 cm (2.4 inches)</td>

<td>total number of holes</td><td> 32</td><td> 32</td>

<td>number of holes used</td><td> 1</td><td>1 and 4</td>

<td>hole layout</td><td>triangular</td><td>triangular</td>

<td>hole diameter, cm (inch)</td><td>0.07812 cm (0.03125 inches)</td><td>0.07812 cm (0.031 25 inches)</td>

<td>temperature of the introduced sludge (° C, ° F)</td><td>260 ° C (500 ° F)</td><td>279.5 ° C (535 ° F)</td>

<td>the number of revolutions per minute</td><td> 900-1500</td><td> 900-1500</td>

<td>throughput per bore in kg / h (lb / h)</td><td>88.5 kg / h (195 lb / h)</td><td>45.5 kg / h (100 lb / h)</td>

Patent claims