EP1287094A2 - Feed nozzle for gasification reactor for halogenated materials - Google Patents

Abstract

Method and apparatus for feeding halogenated material to a gasification reactor including supplying a gaseous source of oxygen at supersonic velocity and discharging a liquid halogenated material from at leat one discharge port radially peripheral to discharging oxygen source gas such that the oxygen gas atomizes the liquid halogenated material into the gasification reactor.

Description

FEED NOZZLE FOR GASIFICATION REACTOR FOR HALOGENATED MATERIALS

This invention relates to feed nozzles for gasification reactors, and more particularly to feed nozzles, sometimes referred to as burners, for gasification reactors for halogenated materials, in particular halogenated organics and chlorinated organics (RCl's).

Related inventions include a prior patent application for a Method and Apparatus for the Production of One or More Useful Products from Lesser Value Halogenated Materials, PCT international application PCT/US/98/26298, published 1 July 1999, international publication number WO 99/32937. The PCT application discloses processes and apparatus for converting a feed that is substantially comprised of halogenated materials, especially byproduct and waste chlorinated hydrocarbons as they are produced from a variety of chemical manufacturing processes, to one or more "higher value products" via a partial oxidation reforming step in a primary gasification reactor and a second, discrete "soak" reactor. In general terms, a gasification reactor for halogenated materials includes, preferably, a refractory lined cylindrical vessel having a mixing nozzle attached at one end. Halogenated materials, typically a mixture or assortment of RCl's, together with oxygen and most likely steam (as well as optionally extra gaseous fuel, water/hydrogen halide vapors and CO ) are fed through the feed nozzle into the gasification reactor and are atomized and produce gaseous partial-oxidation products. A typical set of operating conditions might involve approximately a 170 liter per minute (45 gallon per minute) flow of a liquid (optionally pretreated or preconditioned) halogenated hydrocarbon feed, at approximately 30°C. and 7 bars, gauge (100 psig). Oxygen may be supplied at approximately 450 kilograms (10,000 lbs.) per hour at 120°C. and 14 barg (200 psig). Steam may be provided with the oxygen at approximately 450 kg (10,000 lbs.) per hour, saturated at 10 barg (150 psig). The reactor pressure might operate at 5 barg (75 psig) with a reactor temperature preferably between 1300°C. and 1500°C.

The proper dispersion of the liquid halogenated feed material to the partial oxidation (gasification) reactor is a critical step for the successful operation of the gasification process. Operational goals for the dispersing nozzle, sometimes referred to as the burner, include, for one, the difficult goal of enabling the stable operation of the reactor for a wide range of feed materials with nearly complete reaction of the halogenated material and with a minimization of partially reacted feeds. The total requirements placed upon a reactor feed nozzle in the instant harsh gasification environment present difficult operating limitations indeed. For comparison, even in the related field of coal gasification, which presents or provides a more benign environment than contemplated herein, nozzle design and performance has been known to be a limiting factor on reactor reliability. RC1 gasification processes present unique issues when contrasted, for instance, with coal gasification processes, or even with the gasification of other carbonaceous non- halogenated materials. On the one hand, halogenated materials, such as hydrogen chloride, present an aggressive corrosive potential. Secondly, the feed streams for a gasification reactor of liquids such as liquid RCl's have different attributes than the feed streams of many conventional gasification processes. And for optimal operation of a halogenated material gasification reactor, provision must be made for a plurality of different feed streams of halogenated materials. Multiple feed conduits from multiple sources of halogenated material may be necessary, and the conduits may need to be structured to prevent an undesirable reaction of the multiple feed streams with each other inside the nozzle, if fed simultaneously.

Prior art feed nozzles tend to utilize internal mixing within the nozzle to help ensure an efficient breaking up of a liquid stream for the purposes of a gasification reactor. Internal mixing nozzles are known, for instance, for fuel oil atomization and are believed in that application to achieve the highest operating efficiency. Internal mixing, however, is not a preferred approach in the instant environment. Mixing of the halogenated material and oxygen internal to the nozzle raises safety and activity concerns. Internal mixing in the nozzle could result in contamination inside the nozzle after a shutdown, with shutdown feed tars potentially coating the interior of the nozzle. This contamination might cause oxidation inside the nozzle. One goal of the present invention is consequently to achieve an effective external mixing nozzle, superior from safety and reactivity perspectives. These considerations outweigh the additional complexity of a multi-port design and/or of a lower atomization efficiency and/or of a higher pressure drop on the oxygen. However, at the same time, it is acknowledged that elegant simplicity of design is always a desired advantage for mixing nozzles, to enable higher gasifier reliability. Such simplicity of design is also taught herein as an advantage, but under realistic operating constraints.

As discussed above, the feed nozzle or burner is an integral and vital component of a gasification reactor. The discharge jet from the burner is the momentum source for mixing in the gasifier, and the main burner must atomize the liquid fuel into this mixing jet. A typical target atomization performance is for 99 percent of the liquid volume to be of a droplet size of 500 microns or smaller. This provides for sufficient liquid surface area to enable rapid evaporation of the fuel. Two mechanisms play a role in this atomization. In preferred embodiments, the liquid is injected through an annular arrangement of orifices, centered around a central oxygen discharge, and pressure drop through these orifices initiates a coarse atomization of the discrete liquid jets. The orifices, and thus the liquid jets, are preferably directed to intersect out in front of the face of the burner and more specifically, along the axis of the oxygen discharge, and so intersect with the oxygen discharge jet. In such manner, the oxygen discharge jet provides the primary energy source for fine atomization. Static pressure of the oxygen is converted to kinetic energy through the burner nozzle. The nozzle is preferably a near sonic or more preferably supersonic nozzle and so tends to achieve a maximal velocity. The velocity differential between gas and liquid is the atomization energy which reduces the liquid jet to fine, discrete droplets. A moderator stream of steam may be mixed with the oxygen upstream of the burner in a preferred operating mode. Oxygen to the gasifier is preferably preheated to 120°C. to offset a temperature drop as oxygen is expanded through the nozzle, thus increasing atomization efficiency.

A further aspect of the instant invention is its utilization of the expansion energy of an oxygen source gas exiting through the nozzle to break up and finely atomize impinging liquid feed streams, externally. Such advantageous use of a gas expansion energy mixes an oxygen source gas with an impinging liquid stream external to the feed nozzle and adequately atomizes the liquid external to the nozzle. The design employs available work from expanding oxidizing gas, a gas that has followed a converging and then preferably a diverging gas passageway defined by the internal nozzle structure, to energize, atomize and project liquid fuel into a reactor chamber. The oxygen source gas could be oxygen, steam and/or another gas. Typically the gas is pure oxygen. A preferred converging then diverging design for an oxygen gas passageway maximizes an exit velocity of the gas. One aspect of the invention is to structure and operate a converging and then diverging oxygen gas passageway to achieve sonic flow of the oxygen source gas by the end of the converging portion. Supersonic flow should then be achievable within the subsequent diverging portion of the passageway. (However, a converging only nozzle could optionally be used, especially if the oxygen source gas cannot be accelerated, due to pressure ratios, sufficiently to operate at sonic flow in a converging then diverging nozzle design. In general, while a converging only nozzle design could be used, it is considered to be of lesser efficiency.)

Flame temperatures of over 3,000°C. may be reached upon the mixing of the oxygen source gas and the halogenated material feed. Such temperatures, even though realized slightly downstream of a nozzle tip, can radiate backward to heat downstream portions of the nozzle and potentially shorten nozzle lifetime. Thus, cooling of nozzle tip portions or downstream end portions of the nozzle is a further aspect of the instant design. Cooling is provided by several means, including steam film cooling on exterior portions of the nozzle body and/or by providing for circuits of a cooling medium (for example, water) within a body portion of the nozzle itself. A water cooled jacket, although more complex than steam film cooling, offers an alternate and proven design in the feed nozzle industry and is also disclosed herein as an alternative cooling system. Steam film cooled jackets offer advantages to control metal surface temperatures utilizing more simple mechanical fabrication techniques.

As a further aspect of the invention, an effectively "inert gas," such as steam or CO₂ or HC1 vapor, can be provided to bring about an "inert gas" curtain at the nozzle tip end to further ameliorate radiation back from a hot reaction zone downstream of the nozzle. The invention provides a design for an annular jet of "inert gas" effective for separating an oxidizing gas discharge from a hot reactor environment to help protect the materials of the nozzle from the heat of the reactions. Providing an "inert gas" curtain partially encompassing an oxygen discharge tends to move potential combustion away from the nozzle structure, resulting in a shifting of the location of the most extreme temperatures to further away from the nozzle downstream face. Such protection can reduce potential thermal stresses in nozzle tip materials and lengthen nozzle lifetime. Thus, to avoid induction of hot reaction chamber products into the near pure oxygen jet immediately at the burner face - - and the extreme temperature conditions which result - - a "moderator," or some portion thereof, is preferably jetted into the gasifier as an annular film surrounding the oxygen/fuel jet. This "inert" layer tends to move the hot oxidizing zone out away from the face of the burner, thus reducing the heat flux and resulting temperatures on the burner face. CO and steam are preferred effectively inert gases due to their capacity to absorb infrared radiation. A further aspect of the inventive design is a providing for partitioning or for separate liquid conduits for halogenated materials in order to enable distinct liquid feed streams to be fed separately and simultaneously, if necessary or desired, to a reaction chamber.

The invention comprises a feed nozzle to be used in combination with, and adapted to attach to, a gasification reactor for halogenated materials. The nozzle provides, in one preferred embodiment, a converging then diverging first passageway for a gaseous source of oxygen. The first passageway terminates in a discharge orifice at a downstream end of the nozzle. Although the first passageway could be comprised of a plurality of smaller constituent passageways, a single passageway is contemplated in preferred embodiments. The nozzle design provides at least one second passageway for a liquid feed stream of a halogenated material, the second passageway terminating in at least one discharge port at a downstream end of the nozzle. The preferred embodiments contemplate, in certain cases, providing a plurality of second passageways such that different halogenated materials might be fed and reacted simultaneously. These halogenated materials may advantageously be kept separate prior to the reactor chamber.

The one or more second passageways are in fluid communication with sources of liquid halogenated material. The discharge port of the one or more second passageways is preferably designed to be located radially peripheral to a first passageway discharge orifice. Optionally, a third, effective "inert gas" passageway is provided. The inert gas most preferably would be steam, or primarily steam. The third passageway for the inert gas, which could be one or more smaller constituent passageways, is preferably designed to discharge proximate a discharge port of a second passageway.

Passageways for inert gas, oxygen source gas and halogenated materials are placed in fluid communication with proper sources of the materials. The supply system provides for suitable temperature and pressure control.

Steam utilized in an "inert gas" passageway preferably provides film cooling for downstream ends of the nozzle and also an "inert gas" curtain that tends to protect nozzle tip surfaces from the extreme heat of the gasification reactor in the initial mixing zone. The steam can further function as a reactant, providing a source of oxygen and hydrogen. A pilot and/or startup nozzle passageway is provided for some embodiments. Also a converging only optional design is disclosed. The invention includes a method for feeding liquid halogenated materials to a gasification reactor. The method includes supplying a gaseous source of oxygen, at near sonic or preferably supersonic velocities, to an orifice of a feed nozzle discharging into a gasification reactor. Halogenated material is discharged from at least one discharge port radially peripheral to the discharging oxygen source gas, such that the oxygen source gas energizes and atomizes the halogenated material out into a gasification reactor chamber at least slightly downstream of feed nozzle surfaces. The method includes providing water cooling and/or film cooling for nozzle surfaces as well as providing an "inert gas" curtain proximate the discharge end of the nozzle to help protect nozzle surfaces from the extreme heat of the oxidation reaction. A startup method is additionally provided using a small volume feed gas passageway with the oxygen source gas while the oxygen gas velocity is slowly increased.

A better understanding of the present invention can be obtained when the following detailed description of the preferred embodiment is considered in conjunction with the following drawings, in which:

Figure 1 is an illustrative cross-section showing a converging and diverging passage for an oxygen source gas; also shown is a central pilot nozzle and an annular array of circular outlet ports for halogenated materials; also illustrated is a passageway for inert gas cooling or steam cooling; sources of the feed streams and the discharge end of the nozzle are indicated.

Figure 2 is similar to Figure 1 with a different configuration for the downstream end of the jacket for the inert gas cooling stream.

Figure 3 indicates the nozzle of Figure 2 without a central pilot nozzle.

Figure 4 is similar to Figure 2 but with individual feed pipes for the halogenated material.

Figure 5 indicates an alternate embodiment to Figure 4 having segmented or individual feed pipes for various halogenated materials.

Figure 6 illustrates a nozzle with a cooling medium circuit.

Figures 7 and 8 illustrate a gasification reaction process and a gasifier stage more particularly.

Figure 9 illustrates a converging only nozzle, which could be adapted to any of the configurations of Figures 1-6. A preferred embodiment, in block flow diagram form, of a gasification reaction system for halogenated materials and which is suitable for operation with the present invention, are illustrated in Figures 7 and 8. Figures 7 and 8 will be discussed first to lay a foundation for the instant invention. Gasification reaction process GPR of Figure 7 converts a feed that is substantially comprised of halogenated materials to one or more useful products. These products can be in the form of a useful or salable acid product 50 and/or of a product synthesis gas 54, as indicated in Figure 7. (Alternately, the reaction product from a partial oxidation reforming step of the process, including the same hydrogen halide, carbon monoxide and hydrogen components, could be employed as a feed in the synthesis of a different useful or salable product, which is not indicated in Figure 7.)

With particular reference to the production of an acid product 50 and/or a product synthesis gas 54, as illustrated in Figure 7, the process includes the steps of supplying a partial oxidation reforming reactor zone or gasifier 200 (comprised of one or more partial oxidation reforming reactors in series (as shown in Figure 8) or in parallel) operating under reducing conditions with a feed 56, a source of oxygen 58 and optionally moderator streams (not shown) and optimally a supplemental hydrogen-containing co-feed (not shown) as required to enable the conversion of substantially all of the halogenated materials in the feed to a corresponding hydrogen halide. The process includes steps, illustrated by the preferred embodiment in Figure 7, for recovering from the reactor a reaction product stream 60 comprised predominantly of one or more hydrogen halides, water, carbon monoxide and hydrogen, and containing essentially no unconverted halogenated materials, and then separating out and recovering useful products in a quench and particulate removal stage 300, a particle recovery stage 350, an absorber stage 400, an aqueous acid clean-up stage 450 and a syngas finishing stage 700. Useful products recovered from the reaction product can comprise either or both of a useable or salable halogen acid product and a product synthesis gas.

Figure 8 illustrates in greater detail the operation of a preferred embodiment of a gasifier stage 200, showing oxygen stream 290, optimally heated by oxygen preheater E-290 operated by steam stream 235, fed to main burner BL-200 as stream 291. Steam stream 298 is also fed to the main burner, as is RC1 feed stream 144, preferably from preheater E-140, and fuel gas stream 296 and recycled vapor stream 530 from an upstream distillation unit T- 510. Provision is made for a nitrogen purge of primary gasifier R-200 with nitrogen stream 295. The gasifier units are shown as primary gasifier R-200 and secondary gasifier R-210 in the preferred embodiment.

The method and apparatus of the present invention particularly relate to feed nozzle BL-200 for the gasification reactor R-200. The nozzle designs are useful for the atomization of a variety of halogenated material feeds, to convert them in the reaction process to higher value products. Feeds comprised of a mixture of differently halogenated materials, for example chlorofmorocarbons and/or hydrochlorofluorocarbons with chlorinated hydrocarbons, are contemplated for use through the nozzle, as are feeds including both liquids and solids. Preferably the nozzle feed would be comprised substantially or entirely of liquids. More preferably the feed is essentially ash-free and non- slagging, including less than 5 percent of ash and other inorganic materials, and preferably includes 1 percent or less of such materials.

The gasification reactors R-200 and R-210 preferably operate under reducing conditions with an oxygen source (preferably in the form of one or more oxygen-containing gases selected from oxygen, air, oxygen-enriched air and carbon dioxide, but more preferably being essentially oxygen) and optionally a supplemental hydrogen-containing co- feed as required to enable substantially all of the chlorine content in the feed to be manifested as hydrogen chloride in the reaction product from the partial oxidation reforming reactor zone. Steam can be added as a temperature moderator and additional hydrogen source in keeping with conventional reformer practice, and should be considered as optionally included as other reactants.

Typical burner operating parameters of a nozzle of the instant design might be:

1. Liquid fuel pressure drop: 10 bars (150 psi) at 140 liters/minute (37 gpm). Pressure drop is proportional to the square of the flow as for a typical liquid orifice. Deviations from this relationship indicate potential plugging or coking of the fuel in the nozzle (high differential pressure) or degradation of the nozzle tip (low differential pressure).

2. Oxygen pressure drop: Supersonic nozzles are defined by pressure ratio as opposed to pressure drop. Pressure ratio is the ratio of the absolute pressures: PTJ/PR- Normal operating ratio for the oxygen is 2.75 at 450 kg/hr (10,000 lb/hr). This is the ratio of upstream absolute pressure (Pu) to gasifier chamber absolute pressure (R_R).

3. Oxygen temperature: The oxygen temperature should be maintained at 120°C. to the burner. Due to the high pressure ratio across the burner, the resulting oxygen exit temperature is approximately 25°C. Lower temperatures result in lower velocity, less efficient atomization, and longer evaporation times from the burner.

4. Moderator pressure drop: Pressure drop is effectively proportional to the square of the flow for this low pressure drop gas flow. Deviations indicate degradation of the annular chamber containing the moderator.

Clearly, a feed nozzle for such operations as discussed above, including delivering such feeds into such a harsh environment, is a critical unit. Figure 1 illustrates in cross- section a preferred embodiment of a present inventive feed nozzle. Gasification reactor wall portions R are indicated surrounding the nozzle N. Downstream nozzle end DSE is shown positioned to discharge into an interior zone GR of the gasification reactor. Ports DP indicate radially-arrayed discharge ports for halogenated material feed conveyed through a passageway HMP. Oxygen source gas flows from an oxygen source 10, by means known in the art, through passageway OP to discharge orifice DO at the discharge end DSE of feed nozzle N. Figure 1 further illustrates an effectively "inert gas," preferably steam, flowing from an inert gas source 12 to inert gas passageway IGP defined by the nozzle N. Inert gas passageway IGP is formed in part by jacket Jl of nozzle N. Jacket Jl is illustrated as preferably containing vent ports V in its outer wall. A supplemental fuel gas such as methane is illustrated as flowing from a source 13 in a fuel gas passageway FGP, defined by nozzle N and in part by jacket J2. Passageway PP with one or more discharge ports PDP are defined in a pilot nozzle

PN positioned in the middle of oxygen source gas passageway OP. Pilot nozzle passageway PP, and halogenated material passageway HMP, are both shown as connected to a source 11 of halogenated material. Source 11 could of course be multiple sources of halogenated material, and the halogenated material in the sources could be the same or different. The supplemental fuel gas is also shown as supplied or suppliable to passageway PP from source 13. Passageway PP fundamentally provides a passageway of smaller cross-sectional area for the transport of halogenated material feed to the one or more atomizing ports PDP. During startup of the nozzle, halogenated material feed and oxygen are both supplied at relatively slow flow rates to the nozzle. Passageway PP, providing a smaller volume or cross- sectional area for throughput, enables better atomization of the feed material at these initial lower total flow rates. Figure 2 differs from Figure 1 in that jacket Jl that in part defines inert gas passageway IGP, does not wrap around as far at the downstream end DSE of nozzle N. Jacket Jl helps to define the "inert gas" curtain that can be created.

Figure 3 differs from Figures 1 and 2 to indicate that preferred embodiments need not incorporate a pilot nozzle defining a pilot passageway PP, although such passageway PP could also serve as an alternate or additional liquid halogenated material passageway through the center of a nozzle, as described more completely below.

Figure 4 differs from Figures 1-3 in that Figure 4 specifically indicates and provides for segmented or individual passageways for halogenated material, indicated in Figure 4 as passageway HMPl and passageway HMP2. Such segmented or individual passageways could provide for the gasification of different sorts of halogenated materials, without mixing the halogenated materials until the discharge end of the nozzle in the gasification reactor. An annular halogenated material passageway could alternately be partitioned off to create separate channels.

Figure 5 illustrates a related but different embodiment to that shown in Figure 4. In. the design of Figure 4, segmented or individual material feed passageways are located outside of the passageway OP, while in the design of Figure 5, the individual feed material passageways HMPl and HMP2 are located within the passageway OP. Consideration of the thermal stability of the feed material, and the possibility of leakage of a feed passageway, could affect a choice of design between the embodiments of Figures 4 and 5. In the design of Figure 4, the individual feed passageways would be surrounded by the steam, while in Figure 5 they would be surrounded by the oxygen source gas.

Figure 6 illustrates an alternative embodiment in which wall portions of nozzle N are cooled using a source of a cooling medium, such as water, from source 14 circulated through passageway WP incorporated into a nozzle N. In preferred embodiments of the feed nozzle of the instant invention, as illustrated in

Figures 1-6, an oxygen or oxygen-steam mixture flows through a converging and then diverging passageway terminating in a discharge orifice at the discharge end of the nozzle. The converging and then diverging portion of the nozzle is designed to achieve a supersonic flow of the oxygen-containing gas at discharge, to the extent possible. In a preferred embodiment, halogenated material, such as liquid RC1, would be transported through one or more second passageways and discharged into the supersonic gas stream from a number of discharge ports surrounding the discharge orifice of the oxygen- bearing gas. The discharge ports for the liquidized RC1 would preferably themselves be directed somewhat radially inwardly, toward the discharging stream of oxygen gas. The feed conduits for the liquid RC1 could be subdivided, or segmented as previously discussed, so as to provide separate feed capability for different RC1 streams that are not chemically compatible. For startup purposes, a central pilot nozzle as shown in Figures 1, 2, 4 and 6 is preferably employed for atomizing feed at slow initial flow rates, at a liquid feed spray nozzle discharge port (PDP) at a downstream end of the nozzle. Such design provides a pilot for starting up the nozzle at slow feed and oxygen rates and can conceivably further be used to provide turndown capability for a startup by the reactor for feeding a new incompatible stream.

A separate preheat nozzle (not shown) can be used to heat the gasifier to operating temperature from a cold state as well as to maintain temperature during short RC1 outages, and perform controlled cool-downs from a hot operating state. Due to the large mass of refractory through the gasifier syngas path, a substantial amount of heat must be introduced in a controlled fashion to heat the refractory and gasifier chambers to an operating temperature, preferably before introducing RC1 liquids. Excessive heat-up or cool-down rates might damage refractory due to the thermal stresses induced by temperature gradients. The functionality of a preheat burner is very similar to that described for the primary gasifier and main nozzle or burner operation, except the fuel is preferably fuel gas as opposed to liquid RCl's.

For startup, to heat the refractory, a small, intermittent pilot would ignite a preheat burner. Fuel gas and oxygen can then be introduced and externally mixed by the preheat burner. After a low flow rate, a stable flame can be established and steam moderator can preferably be introduced at approximately a 1 to 1 ratio by mass with the fuel gas. Oxygen to fuel is preferably controlled at a mass ratio of approximately 1.7: 1 to 2.0: 1 during startup. This is slightly less than half of the stoichiometric ratio for complete combustion. Flow rates are slowly ramped up to maintain a controlled refractory heat up rate of approximately 25°C. per hour up to the desired gasifier operating temperature.

In certain of the preferred embodiments, as illustrated in Figures 1-5, the instant nozzle provides, surrounding the RC1 and oxygen passageways, a conduit for feeding an effectively "inert gas," preferably in the form of steam, CO₂ and or water/hydrogen halide vapor. Optionally also, surrounding the inert gas conduit would be a conduit for feeding methane or another fuel gas, as an optional source of extra hydrogen and extra fuel for the reaction process. Select gaseous process vapor streams can be fed to the reactor in place of or in addition to steam or methane. Such process vapor streams would be non-oxidizing streams containing effective inerts, RCl's or hydrocarbons. Cooling vents can be utilized in the inert gas passageway such that surface portions of the nozzle can be cooled by establishing a thin cooling gas film on the surface. Methods for steam film cooling are shown by Lefebvre (Gas Turbine Combustion - 1983).

The passageways of the nozzle, in particular passageways for the oxygen source gas and passageways for the halogenated materials, would be structured in size, in combination with anticipated operating pressures, temperatures and flow rates, to achieve desired discharge end velocities. Oxygen is the preferred atomizing gas. Steam provides an alternate or additional atomizing gas.

In regular operation, an oxygen source gas, such as oxygen and/or steam and/or other oxygen source gas, is provided to an oxygen source gas passageway OP from source 10. Liquid halogenated materials are provided to halogenated material passageway HMP (or passageways HMPl and HMP2) from a source 11 (or sources) of halogenated materials. Halogenated materials or fuel gas can also optionally be placed in fluid communication with a pilot passageway PP, for alternate or additional feed. The nozzle is designed for the oxygen source gas eventually to reach sonic velocities at the end of converging portion CN of the nozzle wall portion defining passageway OP. Through diverging portions DN of nozzle wall portions, found proximate the discharge end DSE of the nozzle, the oxygen source gas is expanded to achieve preferably supersonic velocities. At supersonic velocities, the oxygen gas should adequately disperse and atomize liquid halogenated materials emerging from discharge ports DP in halogenated material passageway HMP (or passageways HMPl and HMP2). Further, the mixing of halogenated materials, such as RCl's, with an oxygen source gas, such as O₂, should take place just downstream of nozzle N, within zone GR defined within the gasification reactor. Jacket Jl is designed to help direct an effectively inert gas, such as steam, along portions of nozzle walls defining a halogenated material passageway and to discharge the inert gas proximate the discharge of the halogenated material, preferably across or into the discharge of the halogenated material, to provide an inert gas curtain. The port for discharge DP of the halogenated material passageway HMP may be advantageously structured to discharge halogenated material partially radially inwardly toward the axis of the nozzle.

Initially the feed material is preferably supplied to passageway PP, during the startup of the nozzle, and exits pilot nozzle tip PT through discharge ports PDP in the pilot nozzle PN, with such pilot nozzle and discharge ports located and structured to initiate the gasification reaction prior to temperatures reaching process temperatures in the reactor 200, prior to the feed reaching its operational flow rate and prior to the oxygen source gas reaching sonic velocity within the nozzle. Pilot nozzle PN may be either continued or turned off once process temperatures, pressures and velocities are reached. Extra fuel gas, such as methane, may be supplied through a passageway defined in part by jacket J2 to the discharge end DSE of nozzle N. Steam, utilized as an inert gas, may vent through vents V of jacket Jl, thereby helping to provide a film cooling of wall portions and downstream end portions of nozzle N.

Figure 9 illustrates a converging only nozzle. The design is anticipated to be less efficient than a converging then diverging design but might be preferred in cases where oxygen will not reach supersonic velocities. Except for the absence of a diverging section, a converging only nozzle design would be constructed and operate in essential respects like the nozzle of Figures 1-6.

In regard to the choice of materials of construction for a feed nozzle, recourse should be taken to standard references and the literature for appropriate materials of construction in a given environment. Use of a Hastelloy B or C material appears preferred.

The foregoing disclosure and description of the invention are illustrative and explanatory thereof, and various changes in the size, shape, and materials, as well as in the details of the illustrated system may be made without departing from the spirit of the invention. The invention is claimed using terminology that depends upon a historic presumption that recitation of a single element covers one or more such elements, and recitation of two elements covers two or more such elements.

Claims

WHAT IS CLAIMED IS:

1. A feed nozzle and gasification reactor in combination, the nozzle providing a converging then diverging first passageway, terminating in a discharge orifice located at a downstream end of the nozzle for discharging an oxygen- containing gas into the gasification reactor, and which is in fluid communication with a source of the oxygen-containing gas; and at least one second passageway terminating in at least one discharge port at a downstream end of the nozzle, wherein the at least one second passageway is in fluid communication with a liquid source of halogenated material and wherein a discharge port of a second passageway is located radially peripheral to a discharge orifice of the first passageway.

2. The apparatus of claim 1 wherein the nozzle provides at least one third passageway having a discharge port proximate a discharge port of a second passageway, the at least one third passageway being in fluid communication with a source of effectively inert gas.

3. The apparatus of claim 2 wherein the inert gas includes steam, CO2 or nitrogen.

4. The apparatus of claim 1 wherein the nozzle structure defines at least one circulating passageway, the at least one circulating passageway being in fluid communication with a source of a cooling medium.

5. The apparatus of claim 2 wherein nozzle structure defining at least one second passageway and at least one third passageway provides, at least in part, that the passageways share a common wall.

6. The apparatus of claim 3 wherein the nozzle structure provides vents in an outer wall of at least one third passageway.

7. The apparatus of claim 1 wherein the nozzle structure defines a fourth passageway having a discharge port at a downstream end of the nozzle, the fourth passageway being in fluid communication with a source of gaseous fuel.

8. The apparatus of claim 4 wherein the nozzle structure provides that at least one circulating passageway and at least one second passageway share, at least in part, a common wall.

9. The apparatus of claim 2 wherein a discharge port of at least one third passageway is structured and oriented in combination with a discharge port of at least one second passageway such that an third discharging the third passageway is directed across a discharge port of a second passageway.

10. The apparatus of claim 1 that includes at least two second passageways and wherein the at least two second passageways are each in fluid communication with a separate liquid source of halogenated material.

11. The nozzle of claim 1 wherein the at least one second passageway discharge port includes an annular port located radially peripheral to a discharge orifice of the first passageway.

12. The nozzle of claim 1 wherein the at least one second passageway includes a plurality of discharge ports located annularly around a respective first passageway discharge orifice.

13. The apparatus of claim 1 wherein the at least one second passageway discharge port is structured to direct liquid discharge at least partially radially inwardly.

14. The nozzle of claim 1 wherein nozzle structure further provides a pilot nozzle element located within the first passageway, the pilot nozzle element terminating in a discharge orifice at a downstream end of the nozzle, the pilot nozzle element being in fluid communication with a source of a gaseous fuel.

15. A method for feeding halogenated material to a gasification reactor, comprising supplying oxygen source gas at near sonic or supersonic velocity to a discharge orifice of a feed nozzle discharging into a gasification reactor; and discharging liquid halogenated material from at least one discharge port radially peripheral to the discharging oxygen source gas such that the oxygen source gas expands into and atomizes the liquid halogenated material in the gasification reactor at least slightly external to the feed nozzle.

16. The method of claim 15 that includes discharging an effectively inert gas proximate to the discharging of the halogenated material.

17. The method of claim 16 wherein discharging effectively inert gas includes discharging steam.

18. The method of claim 15 that includes cooling at least a discharge end of the feed nozzle with a cooling medium circulated within a nozzle passageway.

19. The method of claim 16 that includes passing an effectively inert gas over at least portions of a wall defining a halogenated material passageway and forming an inert gas film upon the wall.

20. The method of claim 17 that includes venting an effectively inert gas from an outer wall defining at least in part an inert gas passageway.

21. The method of claim 15 that includes discharging a supplemental fuel gas at a downstream end of the nozzle into the gasification reactor.

22. The method of claim 16 that includes discharging the effectively inert gas across a discharge stream of the halogenated material at a downstream end of the nozzle.

23. The method of claim 15 that includes separately discharging at least two halogenated materials at the discharge end of the nozzle.

24. A method for startup of a gasification reactor for halogenated materials, comprising supplying an oxygen source gas at a discharge orifice of a feed nozzle discharging into a gasification reactor, discharging a stream of fuel gas at a downstream end of the nozzle within a discharging oxygen source gas, and raising the velocity of the oxygen source gas to sonic velocity within the nozzle.

25. The method of claim 24 that includes gradually discharging liquid halogenated material from at least one discharge port radially peripheral to discharging oxygen source gas as the source gas approaches sonic velocity.

26. A feed nozzle, comprising a nozzle in combination with and adapted to attach to a gasification reactor for halogenated materials; the nozzle providing a converging first passageway, terminating in a discharge orifice located at a downstream end of the nozzle, structured to discharge into the gasification reactor; the first passageway in fluid communication with a gaseous source of oxygen; at least one second passageway, terminating in at least one discharge port at a downstream end of the nozzle; the at least one second passageway in fluid communication with a liquid source of halogenated material and having a discharge port located radially peripheral to a discharge orifice of the first passageway; and at least one third passageway having a discharge port proximate a discharge port of a second passageway, the at least one third passageway being in fluid communication with a source of effective inert gas.

27. The apparatus of claim 26 wherein the nozzle structure defines a fuel gas passageway having a discharge port at a downstream end of the nozzle, the fuel gas passageway being in fluid communication with a source of fuel gas.