WO2025250365A1 - Processes of inhibiting carbonation of chlorobutyl elastomers - Google Patents

Abstract

In at least one embodiment, a process of forming a chlorobutyl elastomer includes polymerizing, in a first reactor, a C4 to C7 isomonoolefin and at least one comonomer to obtain a C4 to C7 isomonoolefin derived elastomer. The process includes transferring, via a line, the C4 to C7 isomonoolefin derived elastomer to a second reactor. The process includes introducing O2 at a flow rate of about 0.0.5 Ibs/hr to about 2.5 Ibs/hr to a chlorine source comprising a chlorinating agent to form a mixture comprising the chlorinating agent and the O2. The process includes introducing, to the second reactor, the mixture comprising the chlorinating agent and the O2 with the C4 to C7 isomonoolefin derived elastomer to form the chlorobutvl elastomer.

Description

PROCESSES OF INHIBITING CARBONATION OF CHLOROBUTYL ELASTOMERS CROSS-REFERENCE TO RELATED APPLICATION [0001] This application claims the benefit of U.S. Provisional Application 63/654494, filed May 31, 2024, entitled “PROCESSES OF INHIBITING CARBONATION OF CHLOROBUTYL ELASTOMERS”, the entirety of which is incorporated by reference herein. FIELD [0002] The present disclosure relates to processes of inhibiting carbonation of chlorobutyl elastomers. BACKGROUND [0003] Due to its low gas and vapor permeability, butyl rubber (such as chlorobutyl elastomer, also referred to as chlorobutyl rubber) is an important material in the manufacturing of tubeless tires, inner tubes, etc. Butyl rubber is typically manufactured by a slurry polymerization of 2-methylpropene (isobutylene) and 2-methyl-1,3-butadiene (isoprene) in diluent in the presence of an initiator and co-inliitiator. Chlorobutyl rubber is typically formed in a two stage process – the first stage is the polymerization of isobutylene and isoprene to produce a “cement” of butyl rubber. The cement is then chlorinated in a second stage of the process by chlorination. [0004] During the chlorination process, formation of soot from carbonation of components of the chlorination process has been problematic for many years. The formation of soot occurs during the chlorination process due to (1) the presence of ferrous chloride inside the piping, (2) if the chlorine is mixed with the butyl rubber cement as a liquid (vs. a gas), or (3) if the mixing is inadequate due to fouling of the mixer. The presence of soot provides a gray tint to the chlorobutyl elastomer that forms during the chlorination process, instead of a chlorobutyl elastomer’s typical white coloration if it is substantially pure. Such gray discoloration may be considered unsuitable for various downstream uses of the chlorobutyl elastomer. Such unsuitable batches of chlorobutyl elastomer are discarded, resulting in substantial financial loss to the manufacturer. [0005] There is a need for improved processes for providing chlorobutyl elastomers having reduced soot content and reduced discoloration. SUMMARY [0006] The present disclosure relates to processes of inhibiting carbonation of chlorobutyl elastomers. [0007] In at least one embodiment, a process of forming a chlorobutyl elastomer includes polymerizing, in a first reactor, a C₄ to C₇ isomonoolefin and at least one comonomer to obtain a C4 to C7 isomonoolefin derived elastomer. The process includes transferring, via a line, the C₄ to C₇ isomonoolefin derived elastomer to a second reactor. The process includes introducing O2 at a flow rate of about 0.05 lbs/hr to about 2.5 lbs/hr to a chlorine source comprising a chlorinating agent to form a mixture comprising the chlorinating agent and the O₂. The process includes introducing, to the second reactor, the mixture comprising the chlorinating agent and the O₂ with the C₄ to C₇ isomonoolefin derived elastomer to form the chlorobutyl elastomer. BRIEF DESCRIPTION OF THE FIGURES [0008] To assist those of ordinary skill in the relevant art in making and using the subject matter hereof, reference is made to the appended figures, wherein: [0009] FIG.1 is a diagram illustrating butyl rubber formation, according to an embodiment. [0010] FIG.2 is a diagram illustrating solvent replacement, according to an embodiment. [0011] FIG. 3 is a diagram illustrating chlorination and neutralization of cement to form chlorobutyl elastomer, according to an embodiment. [0012] FIG.4 is a diagram illustrating finishing of crumbs, according to an embodiment. [0013] FIG. 5 is a diagram illustrating recycle and recovery of diluent and monomers, according to an embodiment. DETAILED DESCRIPTION [0014] The present disclosure relates to processes of inhibiting carbonation of chlorobutyl elastomers. Processes of the present disclosure can provide chlorobutyl elastomers having reduced soot content and reduced discoloration, providing substantial financial cost savings to a manufacturer. [0015] Without being bound by theory, it is believed that hexane solvent used in a typical chlorination process is the species that is carbonated. It has been discovered that introducing an oxygen source into the chlorine used to chlorinate butyl rubber cement can reduce or eliminate soot content and discoloration of the chlorobutyl elastomers formed. [0016] Oxygen can be introduced to a chlorination source at low amounts and flow rates which allow for higher flow rates of butyl rubber cement during chlorination processes, which increases the amount of chlorine available for use during the chlorination processes and improves throughput of chlorobutyl rubber formation. In addition, oxygen injection can make the process more efficient and more sustainable. For example, an increase in the concentration of the rubber in the cement (as measured by increase in the viscosity of the cement) can be utilized provides more efficiency with downstream reslurry operations due to less hexane solvent to flash with steam to form the rubber crumb. Less steam used provides less CO2 generation from the overall process. As an example, for every 100 cP (centipoise) increase in viscosity of the cement, there can be between 2.3 - 2.8% reduction in steam consumption. As the viscosity increases, the amount of solvent to flash remove goes down, and this saves steam. [0017] The oxygen can be introduced at the chlorine source, which can have the advantage of oxygen vapor and chlorine vapor mixing well (e.g., instead of oxygen gas and a liquid (hexane) or solid (butyl rubber cement)). The oxygen vapor and chlorine vapor mixing helps to allow the aforementioned low oxygen amounts and flow rates. [0018] It has also been discovered that lower quality chlorine sources can now be used in chlorination processes due to the introduction of even low levels of the oxygen to the chlorine source during chlorination of butyl rubber. [0019] In addition, use of oxygen with the chlorine does not affect physical properties of the chlorobutyl rubber (e.g., Mooney viscosity), highlighting a hypothesis that carbon soot forms from lower molecular weight carbon-containing components (such as hexane solvent used in a chlorination process) instead of the chlorobutyl rubber itself. [0020] Oxygen (O2) can be provided by an oxygen source that is a mixture of oxygen and a diluent. A diluent can be, for example, nitrogen (N₂). For example, a mixture of nitrogen and oxygen can be used as the oxygen source to prevent soot formation during a chlorination process. A mixture of nitrogen and oxygen is advantageous for complying with flare requirements for commercial manufacturing. For example, 90 wt% nitrogen to 10 wt% oxygen allows a mole percent of oxygen to be below a 5 mol% threshold at the flare during commercial manufacturing. Oxygen supports combustion, so dilution with nitrogen promotes controlled flaring. [0021] In some embodiments, a butyl rubber is manufactured by a slurry polymerization of 2-methylpropene (isobutylene) and 2-methyl-1,3-butadiene (isoprene) in methyl chloride diluent in the presence of an initiator and co-initiator. An initiator is HCl and a co-initiator is aluminum chloride or aluminum alkyl, for example, EADC (ethyl aluminum dichloride) or EASC (ethyl aluminum sesquichloride). The butyl copolymer is then quenched using alcohol or water and routed to a processing unit known as the “solvent replacement process” where the polymer is dissolved in a hydrocarbon solvent to make polymer/solvent solution, hereafter known as cement. The cement, diluent, and monomers are then routed to a series of distillation towers where the diluent and monomers are stripped from the cement, the cement is concentrated and the remainder of the hydrocarbon solvent is recovered for recycle. The cement is sent to storage for subsequent chlorination/neutralization, solvent removal, drying and packaging. The diluent monomer stream from the solvent recovery process is dried, compressed and sent to a series of recycle towers to separate the streams. A high purity diluent stream is recycled for catalyst diluent. A diluent/isobutylene stream and an isoprene stream is recovered for a reactor feed blend. Heavies from the process are purged from the unit. Inerts and light ends from the process are purged from the unit. [0022] A diluent (such as hexane) can be introduced to the chlorination process upstream of the chlorination reactor. [0023] As used herein, a polymer may be used to refer to homopolymers, copolymers, interpolymers, terpolymers, etc. Likewise, a copolymer may refer to a polymer comprising at least two monomers, optionally with other monomers. When a polymer is referred to as comprising a monomer, the monomer is present in the polymer in the polymerized form of the monomer or in the polymerized form of a derivative from the monomer (i.e., a monomeric unit). However, for ease of reference the phrase comprising the (respective) monomer or the like is used as shorthand. Likewise, when catalyst components are described as comprising neutral stable forms of the components, it is well understood by one skilled in the art, that the ionic form of the component is the form that reacts with the monomers to produce polymers. [0024] Elastomer refers to a polymer or blend of polymers consistent with the ASTM D1566 definition: “a material that is capable of recovering from large deformations, and can be, or already is, modified to a state in which it is essentially insoluble, if vulcanized, (but can swell) in a solvent.” Elastomers are often also referred to as rubbers; the term elastomer may be used herein interchangeably with the term rubber. Elastomers may have a melting point that cannot be measured by Differential Scanning calorimetry (DSC) or if it can be measured by DSC is less than 40° C., such as less than 20° C., such as less than 0° C. Elastomers may have a glass transition temperature (Tg) [0025] Mooney viscosity or viscosity means the viscosity measure of polymers (e.g., rubbers). It is defined as the shearing torque resisting rotation of a cylindrical metal disk (or rotor) embedded in a polymer within a cylindrical cavity. The dimensions of the shearing disk viscometer, test temperatures, and procedures for determining Mooney viscosity are defined in ASTM D1646. Mooney viscosity is measured in Mooney units and reported herein as ML 1+8 at 125° C. [0026] Isoolefin refers to any olefin monomer having at least one carbon having two substitutions on that carbon. Multiolefin refers to any monomer having two or more double bonds. In at least one embodiment, the multiolefin is any monomer comprising two conjugated double bonds such as a conjugated diene like isoprene. [0027] Isobutylene based elastomer or polymer refers to elastomers or polymers comprising at least 70 mol % isobutylene units. Elastomer [0028] Elastomeric polymers (e.g., rubbers) of the present disclosure include elastomers derived from a mixture of monomers, the mixture of monomers having at least (1) a C4 to C₇ isoolefin monomer component with (2) at least one multiolefin or other polymerizable monomer component. The isoolefin can be present in a range of 70 to 99.5 wt % by weight of the total monomers, such as 85 to 99.5 wt %. The multiolefin derived or other polymerizable monomer component is present in amounts of about 30 wt % to about 0.5 wt %, or about 15 wt % to about 0.5 wt %, or about 8 wt % to about 0.5 wt %. [0029] The isoolefin can be a C4 to C7 compound, non-limiting examples of which are compounds such as isobutylene, isobutene, 2-methyl-1-butene, 3-methyl-1-butene, 2-methyl- 2-butene, 1-butene, 2-butene, methyl vinyl ether, indene, vinyltrimethylsilane, hexene, and 4- methyl-1-pentene. The multiolefin can be a C4 to C14 multiolefin such as isoprene, butadiene, 2,3-dimethyl-1,3-butadiene, myrcene, 6,6-dimethyl-fulvene, hexadiene, cyclopentadiene, and piperylene. Other polymerizable monomers such as styrene and dichlorostyrene are also suitable for homopolymerization or copolymerization in butyl rubbers. [0030] Elastomers can include isobutylene-based copolymers. As stated above, an isobutylene based polymer refers to a polymer (e.g., elastomer) having at least 70 mol % repeat units from isobutylene and at least one other polymerizable unit. These polymers are also conventionally referred to as butyl rubbers. In some embodiments, butyl rubber is obtained by reacting isobutylene with 0.5 to 8 wt % isoprene, or reacting isobutylene with 0.5 wt % to 5.0 wt % isoprene—the remaining weight percent of the polymer being derived from isobutylene. [0031] Other elastomeric polymers of the present disclosure can be derived from at least one random copolymer comprising a C₄ to C₇ isoolefin and an alkylstyrene comonomer. The isoolefin may be selected from any of the above listed C4 to C7 isoolefin monomers, and can be an isomonoolefin, and may be isobutylene. The alkylstyrene may be para-methylstyrene, containing at least 80%, such as at least 90%, such as at least 95%, by weight of the para-isomer and can also include functionalized terpolymers. The random copolymer has at least one or more of the alkyl substituents groups present in the styrene monomer units. In some embodiments, the elastomer comprises random polymers of isobutylene and 0.5 to 20 mol % para-methylstyrene. [0032] In some embodiments, other useful elastomers include other unsaturated copolymers of isoolefins. Non-limiting examples of such unsaturated polymers are poly(isobutylene-co-butadiene), star-branched isobutylene-isoprene, star-branched isobutylene-p-methylstyrene, isobutylene-isoprene-alkylstyrene block polymers and random polymers of isobutylene-isoprene-alkylstyrene. [0033] In some embodiments, a chlorobutyl elastomer (chlorobutyl rubber) of the present disclosure can have about 0.1 mol% to about 3 mol% of isoprene (chlorinated + unchlorinated), such as about 0.5 mol% to about 3 mol%, such as about 1.5 mol% to about 1.8 mol%, such as about 1.6 mol% to about 1.7 mol%, based on the total moles of monomeric units (e.g., isoprene (chlorinated + unchlorinated) + isobutylene). [0034] As used herein, chlorobutyl rubber can be described as having different types of monomeric units known as structure 1, structure 2, and structure 3, etc. Structure 1 refers to unchlorinated isoprene units. Structure 2 refers to isoprene units that are chlorinated at a carbon atom along the polymer backbone (e.g., not at a methyl substituent of isoprene units). Structure 3 refers to isoprene units that are chlorinated at a methyl substituent (e.g., not at a carbon atom along the polymer backbone of the isoprene units). A chlorobutyl elastomer (chlorobutyl rubber) of the present disclosure may have about 0.6 mol% to about 2 mol% structure II units, such as about 0.75 mol% to about 1.5 mol%, such as about 1.1 mol% to about 1.3 mol%, based on the total moles of monomeric units. A chlorobutyl elastomer (chlorobutyl rubber) of the present disclosure may have about 0.01 mol% to about 0.25 mol% structure I units, such as about 0.1 mol% to about 0.225 mol%, such as about 0.16 mol% to about 0.2 mol%, based on the total moles of monomeric units. [0035] In some embodiments, a chlorobutyl elastomer (chlorobutyl rubber) of the present disclosure can have about 20 ppm or less of diluent stabilizer content, such as about 15 ppm or less, such as about 10 ppm or less, such as about 7 ppm or less. Butyl Rubber Processes [0036] The above elastomers may be produced by any suitable polymerization process. The elastomers can be produced in either a slurry polymerization process or a solution polymerization process. If the polymer is produced in a slurry polymerization process where the polymer precipitates out of the reaction medium, then the polymer is dissolved into a suitable solvent, e.g., the creation of a polymer cement, prior to chlorination. For polymers produced via a solution process, after removal of unreacted monomers and removal or neutralization of unused catalysts, the same polymer containing solution, or polymer cement, may be used for chloronation. The elastomer cement can contain about 1 wt % to about 70 wt % polymer, such as about 10 wt % to about 60 wt % polymer, such as about 10 wt % to about 50 wt % polymer, such as about 10 wt % to about 40 wt % elastomer. Monomer Preparation [0037] High purity isobutylene (typically about 98 wt% to about 100 wt%) and isoprene (such as about 98.5 wt % to about 99.9 wt %) can be used for the manufacture of butyl rubber. Impurities can have an impact on isobutylene/isoprene conversion, polymer molecular weight distribution, and reactor performance. The monomer purity is controlled by purchase specifications and stringent quality control with additional purification completed at the production unit if desired. High purity isobutylene can be derived from fossil fuels, advanced recycling processes, or bio based sources. Catalyst Preparation [0038] The high purity diluent (typically about 98 wt% to about 100 wt%) used for catalyst diluent from a diluent recovery tower is combined with the initiator and then the catalyst. The initiator is typically HCl, the catalyst is typically either aluminum alkyl catalyst or aluminum chloride catalyst. FIG. 1 is a diagram 100 illustrating butyl rubber formation. When an aluminum alkyl catalyst is used, the catalyst diluent and catalyst are combined at 102 and mixed with static mixers to ensure good distribution. When aluminum chloride catalyst is used, the catalyst diluent stream is split and one portion of the catalyst diluent is chilled at 104 and sent through aluminum chloride dissolving bed(s) and subsequently recombined with the other portion of the catalyst diluent to achieve the desired catalyst concentration. The catalyst/diluent/initiator stream is injected into the reactor(s) 106 at a high velocity to ensure good distribution in the reactor, such as about 1.5 m/s to about 5 m/s. The catalyst to initiator ratio can be about 1 mol/mol to about 5 mol/mol, such as about 1.5 to about 2.5 mol/mol. [0039] The reaction is sensitive to oxygenated compounds, oxygen and moisture. Moisture is removed from fresh isoprene at 108 and isobutylene at 110 before being sent to the reactor 106. The diluent/monomer recycle stream is dried at 112 with fixed bed alumina and/or molecular sieve driers to remove residual moisture and oxygenated compounds. The recycled solvent stream is dried at 114 with fixed bed molecular sieve driers or by fractionation before reuse in the process. The recycle streams and raw material streams are fitted with moisture analyzers, oxygen analyzers, and oxygenate analyzers to assure moisture, oxygen and oxygenate levels are controlled. Light ends including oxygen are purged from the diluent recovery tower distillate drum. Feed Blend and Reactors [0040] Isobutylene and isoprene in diluent are prepared to a predetermined composition in a feed blend drum at 116, chilled to -90 ^oC to -100 ^oC using a series of heat exchangers and fed to reactor(s) 106. A catalyst and co-catalyst are prepared in high purity diluent and fed to the reactor(s) 106. A copolymer of isobutylene and isoprene is made in the reactor(s) 106. An example diluent used is methyl chloride. In some embodiments, the feed blend contains about 20 wt % to about 40 wt % isobutylene and about 0.4 wt % to about 1.4 wt % isoprene depending on the grade with the remainder being mainly diluent. [0041] Butyl reactors foul with time and are taken out of service periodically to be cleaned. The butyl reaction process can thus be a semi batch process with a number of reactors producing and a number of reactors in non-production mode. At the end of the production cycle the producing reactor is quenched by injecting alcohol or water into the reactor to stop the reaction and then flushed with diluent at a temperature of about -40 ^oC to -80 ^oC to remove the bulk of the rubber slurry and gradually warm the reactor. Solvent is introduced to further warm the reactor up to 0 ^oC to 50 ^oC. The reactor 106 is then washed with solvent at a temperature of 0 ^oC to 90 ^oC to remove the rubber foulant that has accumulated on the vessel surface. When the reactor 106 is clean, the solvent is displaced with diluent at -40 ^oC to -80 ^oC to gradually cool the reactor down and then chilled down to -90 ^oC to -100 ^oC in preparation for production. The flowrates, temperatures, and duration of each of the non-production stages are managed to ensure the mechanical design conditions of the reactor and reactor pump are not compromised. [0042] When the reactor 106 is chilled for production, the reactor 106 is primed with a mixture of diluent, isobutylene, and isoprene. The diluent isobutylene and isoprene concentrations are set to emulate the normal background concentrations during reactor production to ensure the polymer is quickly at specification. The initiator and co-initiator are then injected at high rates to ensure the reaction initiates rapidly before being set to normal rates to assure the rubber is at specification. Solvent Replacement Process [0043] An alcohol or water quench is injected into the reactor overflow outlet to quench the catalyst at 118, e.g., as described in U.S.4,154,924 incorporated by reference herein. FIG. 2 is a diagram illustrating solvent replacement 118. As shown in FIG. 2, quench 202 may be premixed with polar diluent and may then be diluted with solvent, with or without a static mixer, before adding to the reactor outlet. The quench 202 is injected and mixed at 204 with the reactor slurry with or without a mechanical mixer. The resulting stream is then routed to a solution drum 206 where solvent vapor 208 is added to heat the process and dissolve the polymer to make a polymer/solvent solution known as cement. A typical solvent is a mixture of normal hexane and isomers of hexane. The solution drum liquid outlet 210 is then routed to a surge drum 212. The solution drum 206 and surge drum 212 may be combined into a single drum. The solution may be sampled and analyzed periodically to monitor polymer properties. Statistical Process Control techniques and fundamental or empirical models may be used to monitor product quality and guide optimization of polymerization conditions. The drum(s) operating temperatures can be about -20 ^oC to about +30 ^oC, such as about -20 ^oC to about +10 ^oC and the operating pressures can be about 0 kPag to about 1000 kPag, such as about 0 kPag to about 500 kPag. The process is operated to generate a vapor stream of about 0% to about 30% of the total drum feed, e.g., as described in U.S. Patent No. 3,257,349 incorporated by reference herein. The liquid stream from these drums having cement/solvent/diluent/unreacted monomers is routed to a cement stripping tower 214 via line 216. The vapor stream having solvent/diluent/unreacted monomers from the drums 206 and 212 is routed to either the cement stripping tower 214 via line 216 or the cement stripping tower overheads via line 218. The cement stripping tower 214 is a 20-60, such as 40-60, dual flow tray suitable for fouling service, for example the TECHNIP RIPPLE TRAY^TM tower, e.g., as described in U.S. 3,257,349. Solvent vapor is injected at the bottom of the tower via line 220 and flows counter currently to the cement. The cement stripping tower overheads having diluent, unreacted monomers, and a portion of the solvent is routed via line 222 to a solvent recovery tower 224 where high purity solvent is recovered in the bottoms stream (line 226) for recycle and diluent, unreacted monomers are recovered in the overheads (line 228) and sent to the diluent recycle stream driers 230. [0044] The cement stripping tower 214 is operated to ensure that the monomer concentration is very low in the cement stream as any monomers could react in subsequent chlorination processes and exceed desired product specifications (e.g., Industrial Hygiene control). The monomer concentration in the cement stream (line 232) is < 200 wtppm and typically < 50 wtppm for good industrial hygiene control. [0045] The bottoms cement stream (line 232) from the cement stripping tower 214 is flashed into 1-2 cement concentrator drums 234. The cement is cooled and the cement concentration increased. The cement concentrator overheads vapor stream (line 234) has a temperature that is determined by the utilities temperature, typically cooling water or air. The operating pressure of the concentrator drum(s) 234 is determined by the solvent vapor pressure curve, the typical solvent is a mixture of normal hexane and isomers of hexane. The cement concentrator(s) 234 are operated at a pressures of about 40 kPaa to about 150 kPaa, such as about 50 kPaa to about 100 kPaa, e.g., as described in U.S. Patent No.3,257,349. The cement concentrator drum 234 is fitted with side to side trays or baffle plates (shower deck) that allow the solvent vapor to separate from the viscous cement and minimize vapor entrainment in the bottoms cement stream (line 236). The overheads solvent from the cement concentrator is recycled in the process. The bottoms cement stream (line 236) is sent to storage 238. The cement concentration sent to storage 238 is about 18 wt % to about 30 wt %, such as about 22 wt % to about 28 wt%. Heat integration is used extensively in the solvent recovery part of the plant and the reslurry part of the unit to maximize energy efficiency. Chlorination and Neutralization [0046] Chlorination and neutralization can be performed using any suitable process. FIG. 3 is a diagram 300 illustrating chlorination and neutralization of cement to form chlorobutyl rubber. As shown in FIG. 3, the cement from storage 238 is pumped via pump 302 and line 304 to a well-mixed chlorination reactor 306 where chlorine (e.g., Cl2, AlCl3, FeCl3, SbCl3, BCl₃, PCl₃, ClO₂, or combinations thereof) of chlorine source 340 is added via line 308 to form chlorobutyl rubber. The chlorine can be vapor chlorine. [0047] Oxygen is provided from oxygen source 344 to chlorine source 340 via line 342. In some additional or alternative embodiments (not shown), oxygen is provided from oxygen source 344 to line 308. The oxygen can be oxygen vapor. For example, oxygen can be flowed to chlorine source 340 (or line 308) such that the chlorine of chlorine source 340 (or line 308) has an oxygen content of about 50 to about 600 ppm on mass/mass chlorine basis, such as about 250 ppm to about 550 ppm, such as about 250 ppm to about 500 ppm, such as about 250 ppm to about 350 ppm, alternatively about 400 ppm to about 500 ppm, alternatively about 375 ppm to about 425 ppm. The oxygen content of the chlorine of chlorine source 340 (or line 308) translates to about 2 ppm to about 100 ppm oxygen to cement on a rubber basis, such as about 5 ppm to about 25 ppm, such as about 5 ppm to about 10 ppm, alternatively about 25 ppm to about 75 ppm, such as about 25 ppm to about 35 ppm. In some embodiments, oxygen is provided to chlorine source 340 (or line 308) at a flow rate of about 0.05 lbs/hr to about 2 lbs/hr, such as about 0.1 lbs/hr to about 1.2 lbs/hr, such as about 0.1 lbs/hr to about 0.5 lbs/hr, such as about 0.1 lbs/hr to about 0.2 lbs/hr, alternatively about 0.5 lbs/hr to about 1.2 lbs/ hr, such as about 0.7 lbs/hr to about 1 lbs/hr, alternatively about 0.2 lbs/hr to about 0.4 lbs/hr. [0048] In some embodiments, oxygen is provided by an oxygen source that is a mixture of oxygen and a diluent. A diluent can be, for example, nitrogen. For example, a mixture of nitrogen and oxygen can be used as the oxygen source to prevent soot formation during a chlorination process. A mixture of nitrogen and oxygen is advantageous for complying with flare requirements for commercial manufacturing. For example, 90 wt% nitrogen to 10 wt% oxygen allows a mole percent of oxygen to be below a 5 mol% threshold at the flare during commercial manufacturing. In some embodiments, the mixture of oxygen and diluent comprises about 2 mol% to about 15 mol% oxygen, such as about 5 mol% to about 12 mol%, such as about 8 mol% to about 11 mol%. In some embodiments, the mixture of oxygen and diluent comprises about 80 mol% to about 99 mol% diluent, such as about 85 mol% to about 95 mol%, such as about 88 mol% to about 92 mol%. Oxygen supports combustion, so dilution with diluent, such as nitrogen, promotes controlled flaring. In some embodiments, a mixture of diluent and oxygen is provided to chlorine source 340 (or line 308) at a flow rate of about 0.5 lbs/hr to about 20 lbs/hr, such as about 1 lbs/hr to about 12 lbs/hr, such as about 1 lbs/hr to about 5 lbs/hr, such as about 1 lbs/hr to about 2 lbs/hr, alternatively about 5 lbs/hr to about 12 lbs/ hr, such as about 7 lbs/hr to about 10 lbs/hr. [0049] The mixture of oxygen and chlorine (e.g., vapors) formed in chlorine source 340 (or line 308) is provided to chlorination reactor 306 via line 308. For example, chlorine gas of chlorine source 340 can have a pressure of about 140 PSI to about 160 PSI, such as about 150 PSI, and a temperature of about 150 ^oF to about 200 ^oF. The oxygen gas is injected into the chlorine vapor (in chlorine source 340 or line 308). The chlorine gas with the oxygen gas (in chlorine source 340 or line 308) has a pressure of about 120 PSIA to about 140 PSIA and a temperature of about 135 ^oF to about 190 ^oF upon introduction to halogenation reactor 306. [0050] In an embodiment, oxygen (optionally in combination with a diluent, such as nitrogen) may be added at a location other than or in addition to chlorine source 340, such as oxygen introduced to line 304. However, it has been discovered that great benefits are obtained by providing oxygen to chlorine source 340 (or line 308) (e.g., as oxygen vapor to chlorine vapor), whereas oxygen addition at alternative locations is not nearly as beneficial. For example, providing oxygen to chlorine source 340 (or line 308) is beneficial if contaminants, such as iron chloride, are present in the chlorine of chlorine source 340. [0051] The chlorination reactor 306 can be a CSTR (continuous stirred tank reactor) or a high speed mixing device such as a CONTACTOR^TM from STRATCO^TM. In some embodiments, chlorination reactor 306 is a mixed flow stirred tank, a conventional stirred tank, a packed tower, or a pipe with sufficient flow and residence time to permit the desired reaction to occur. Additional pipework and valves may be included downstream to control reaction residence time. Dilution solvent (e.g., hexane) and optional diluent stabilizer is introduced at any suitable portion of the chlorination process, such as cement tank 238, pump 302, chlorination reactor 306, or (as shown in FIG.3) at line 304 via line 336. [0052] In some embodiments of a chlorination process, isobutylene-based polymers having unsaturation in the polymer backbone, such as isobutylene-isoprene polymers, may be chlorinated using an ionic mechanism during contact of the polymer with the chlorine-oxygen mixture of line 308 at a temperatures of about 30 °C to 80 °C and pressure of about 300 kPaa to about 750 kPaa, such as about 450 kPaa to about 500 kPaa. [0053] The chlorinated cement and reaction by-products (line 310) are then mixed with a neutralizing agent (such as sodium hydroxide) (line 320) in first neutralization unit 312 to neutralize the resultant HCl. The first neutralization stage may be 1-4 individual process units and may be a CSTR, a CONTACTOR^TM, a static mixer, or a combination thereof. The stream (line 314) from the first neutralization unit 312 is then mixed with an additive in second neutralization unit 316 to complete neutralization and to form a stable emulsion. The additive is typically calcium stearate dispersion with a surfactant (line 318). In some embodiments, a surfactant is a non-ionic alcohol ethoxylate, such as ethoxy tridecyl alcohol. The second stage neutralization process unit may be 1-4 individual process units and may be a CSTR, a CONTACTOR^TM, a static mixer, or a combination thereof. [0054] The water/hydrocarbon emulsion from the chlorination and neutralization section (line 322) is routed to flash drum 324 and stripper 338 vessels to remove and recover the solvent (line 328). The water/hydrocarbon emulsion is flashed into an agitated flash drum 324 where steam is injected into the liquid to strip the solvent from the stream. A rubber crumb is formed in the flash drum 324, an additive (line 326) is added to the flash drum 324 to prevent polymer agglomeration and vessel plugging. The additive is typically calcium stearate dispersion with a surfactant. The water/crumb mixture flows to an agitated stripper 338 where additional residence time and reduced pressure allows the solvent to diffuse from the crumb to the vapor stream (line 330). Additional steam may be injected into the stripper 338 to aid the solvent diffusion process. Water is sprayed into the vapor space of the flash drum 324 and the vapor space of the stripper 338 to reduce vessel fouling and provide cooling, the spray pattern is typically either hollow cone or solid cone. The slurry concentration to the flash drum 324 and stripper 338 process units is controlled to minimize agglomeration and the propensity for plugging by, for example, controlling flow rates of the calcium and surfactant injected into the flash drums to manage the crumb size within a desirable operational parameter. Lower injection rate provides higher crumb size and vice versa. [0055] The solvent/water in the vapor streams (line 328) from the flash drums is condensed and the solvent separated in a condenser/separator 332 and sent to storage for subsequent drying and recycle, the water is recycled in the process. [0056] During chlorobutyl production, the cement temperature to chlorination is controlled to less than 65 ^oC, such as 20 ^oC to 65 ^oC, or 40 ^oC to 60 ^oC, to ensure favorable reaction to meet final product cure properties. [0057] Flash drum 324 is operated at a pressure of about 140 kPaa to about 190 kPaa, and the liquid temperature is about 105 ^oC to about 120 ^oC. The stripper 338 pressure can operate at a pressure of about 80 kPaa to about 130 kPaa, such as about 90 kPaa to about 120 kPaa, and the liquid temperature is about 90 ^oC to about 110 ^oC. The stripper 338 pressure is controlled by vacuum pumps or vacuum jets. The stripper overheads stream (line 330) is recycled to the flash drum(s) 324 for energy conservation. In larger production facilities multiple flash drum(s) and stripper(s) may be operated in parallel. In facilities where parallel flash drum(s) and stripper(s) are employed, instrumentation can be used to ensure even flow distribution between the parallel units. [0058] Flash drum 324 can have agitators to ensure good mixing between cement and water and to promote crumb formation such as eccentric flat blade agitators. Stripper 338 agitators to ensure good mixing of floating rubber particles in liquid include up or down pumping pitched blade turbines, up or downpumping hydrofoils. [0059] The crumb size can be controlled in the flash drum 324 and stripper 338, because too small crumbs results in vessel and pipework fouling and difficulty dewatering/drying, whereas too large crumbs makes solvent removal difficult and may result in pipework plugging. Crumb size is controlled by calcium stearate addition, calcium stearate particle size and particle size distribution, and surfactants added with the calcium stearate. Crumb size distribution is measured and monitored, e.g., depending on downstream processing such as extruder sizing. [0060] In some embodiments, a chlorination process of the present disclosure is a regenerative chlorination process. Conventional regenerative chlorination processes can occur by contacting a polymer solution with a chlorinating agent and an emulsion containing an oxidizing agent. The oxidizing agent interacts with hydrogen halide created during chlorination, converting the chlorine back into a form useful for further chlorination of the polymer thereby improving the chlorine utilization. [0061] For regenerative chlorination, an emulsion is fed per feedstream E into the chlorination reactor 306. The emulsion includes the oxidizing agent, water, solvent, and an emulsifying agent, such as a surfactant. The emulsion is prepared by providing about 10 wt % to about 80 wt %, such as a 20 wt % to about 70 wt % or about 25 to about 45 wt %, solution of the oxidizing agent in water and mixing this with a solvent and an emulsifying agent under suitable mixing conditions to form a stable emulsion. The emulsion may be achieved by mixing the aqueous phase into the emulsifying agent containing solvent, or by mixing the oxidizing agent with the emulsifying agent first and then combining with the solvent. The amount of oxidizing agent can be about 0.1 to 3, such as about 0.25 to about 3, such as about 0.5 to about 3 moles of active oxidizing agent per mole of chlorinating agent. Use of an oxidizing agent during chlorination increases chlorine utilization to about 70 to 85%. [0062] Oxidizing agents useful in a process of the present disclosure are materials which contain oxygen, such as water soluble oxygen containing agents. Suitable agents include peroxides and peroxide forming substances such as hydrogen peroxide, organic hydrogen peroxide, sodium chlorate, sodium bromate, sodium hypochlorite or bromite, oxygen, oxides of nitrogen, ozone, urea peroxidate, acids such as pertitanic perzirconic, perchromic, permolybdic, pertungstic, perunanic, perboric, perphosphoric, perpyrophosphoric, persulfates, perchloric, perchlorate and periodic acids. Of the foregoing, hydrogen peroxide and hydrogen peroxide-forming compounds, e.g., per-acids and sodium peroxide, have been found to be highly suitable for carrying out chlorine regeneration. [0063] The choice of solvent for the emulsion may be any solvent suitable for use or used in forming the elastomer cement. In one embodiment, the solvent is selected to be the same solvent used to form the elastomer cement. Suitable solvents include hydrocarbons such as pentane, hexane, heptane, and the like, inert halogen containing hydrocarbons such as mono-, di-, or tri-halogenated C1 to C6 paraffinic hydrocarbon (such as methyl chloride, methylene chloride, ethyl chloride, ethyl bromide, dichloroethane, n-butyl chloride) or a halogenated aromatic hydrocarbon (such as monochlorobenzene), or mixtures of the hydrocarbon and inert halo-hydrocarbon solvent. Furthermore, the solvent may be a combination of the solvents provided herein, including isomers thereof. [0064] The emulsion fed via feedstream E may be introduced into the chlorination reactor 306 at the beginning of the chlorination cycle or after consumption of the chlorine via chlorination of the elastomer has begun. The chlorination reaction and the chlorine regeneration reaction can occur at a temperature of about 20 °C to about 90 °C for a time sufficient to complete chlorination of the polymer. When molecular chlorine is the chlorinating agent introduced via feed stream (line) 308, chlorine consumption is indicated by a color change of the reaction mixture. Following sufficient reaction time in the chlorination reactor 306, the effluent, via line 310, exiting the chlorination reactor 306, is neutralized, e.g., as described above. Diluent stabilizers [0065] A free-radical stabilizer, free-radical scavenger, or antioxidant, collectively referred to herein as a “diluent stabilizer”, is provided at a location upstream of the chlorination reactor. The diluent stabilizer may be organic-soluble or a water compatible compound, such as an oil- soluble compound or a hexane-soluble compound. [0066] Suitable diluent stabilizers include sterically hindered nitroxyl ethers, sterically hindered nitroxyl radicals, butylated hydroxytoluene (BHT), hydroxyhydrocinnamite, thiodipropinoate, phosphites, and combinations thereof. [0067] The sterically hindered nitroxyl ether may have a structure represented by either formula (I), where n is a number from 1 to 10 and each instance of R¹ is independently C1-C10 alkyl, such as methyl, ethyl, propyl, butyl, pentyl. C₄H₉ C₄H₉ N N N N N N the formula (II), where n is a number from 1 to 10. C₄ ^H ₉ C₄H₉ N N N N N during the preparation of chlorobutyl rubbers of the present disclosure include, but are not limited to, TEMPO, TINUVIN™ NOR 371, IRGANOX® PS 800, IRGANOX® 1035, IRGANOX® 1010, IRGANOX® 1076, IRGAFOS® 168. TEMPO is a term generally used to refer to (2,2,6,6-tetramethylpiperidin-1-yl)oxy. The sterically hindered nitroxyl radical may be TEMPO. TINUVIN™ NOR 371 may be used which is a high molecular weight hindered amine NOR stabilizer, commercially available from BASF as a plastic additive. Irganox PS 800 may be used, which is commercially available from CIBA and is the trade name of _{didodecyl- -thiodipropionate. Irganox 1035 may be used and is commercially available from} CIBA/BASF and is the trade name of thiodiethylene bis(3,5-di-tert-butyl-4- hydroxyhydrocinnamate). IRGANOX® 1010 may be used which is commercially available from BASF and is the trade name of pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4- hydroxyphenyl)propionate). IRGANOX® 1076 may be used which is commercially available from CIBA and is the trade name of octadecyl-3-(3,5-di-tert.butyl-4-hydroxyphenyl)- propionate. Sterically hindered phenolics may include BHT, IRGANOX® PS 800, Irganox 1035, or combinations thereof. IRGAFOS® 168 may be used which is commercially available from BASF and is a general purpose phosphite. In some embodiments, other structure III stabilizers may be added to the bromobutyl-rubber of the present disclosure including, but not limited to, light stabilizers and UV-absorbers. [0070] In an embodiment, the diluent stabilizer may be added in more than one location in the chlorination process. [0071] In some embodiments, the total amount of diluent stabilizer to be added during the process of preparing the chlorobutyl rubber is greater than or about 20 ppm, such as greater than 50 ppm, such as greater than 75 ppm, such as greater than 100 ppm, to less than or about 500 ppm, such as less than or about 400 ppm, such as less than or about 300 ppm, such as less than or about 200 ppm, such as less than or about 150 ppm, such as less than or about 100 ppm. The ppm weight basis is the weight relative to the chlorobutyl rubber (whether in solution, slurry, or recovered). Finishing [0072] The bottoms stream at 334 from the stripper(s) containing rubber crumb and water is routed to an agitated slurry tank 402, as shown in FIG.4. FIG.4 is a diagram 400 illustrating finishing of the crumbs. Typically pitched blade impellors or a combination of pitched blade impellors and flat blade impellors in up or downpumping mode are used. [0073] The rubber crumb/water slurry is pumped to a dewatering screen(s) 404 to remove gross water. The rubber crumb is then fed to 2-3 extruders in series to dewatering extruder 406 and drying extruder 408 the rubber crumb. The dewatering/first stage drying extruders 406, 408 may be one or more of the following: expanders, expellers, dewatering extruders, slurry dewatering units, volatiles control unit. The final stage drying extruders may be dual worm drying extruders, e.g., as described in U.S. Patent No. 7,858,735 incorporated by reference herein. The temperatures and pressures in the extruders are controlled by adjusting the restriction at the extruder outlet typically with a fixed or variable die plate. Heat may be added by steam jacketing the extruders. Inert gas may be injected to improve drying, as described in U.S. Patent No.4,508,592 incorporated herein by reference. Polymer additives are injected at various stages of the extrusion process to meet product specifications and depending on the grade may consist of none, one, or more of the following polymer additives: epoxidized soy bean oil, calcium stearate butylated hydroxytoluene, Irganox, or antioxidants. [0074] The crumbs from the final drying extruder are then transported (line 410) to a fluidized bed conveyor 412 for drying to product specification, the rubber crumb may be transported by mechanical conveyors. In some embodiments, the fluidized bed conveyor 412 has 2 sections consisting of a primary hot section for drying the crumbs and secondary cool section to cool the crumbs. The crumbs from the fluidized bed conveyor 412 are then routed to a packaging unit 414 where the crumb is compacted into bales, packaged and quality checked. The final rubber polymer product at 416 is stored in warehouse for distribution to customers. Large production facilities operate multiple extrusion and fluidized bed drying lines in parallel. The solvent vapors from the slurry tank, the extruders and fluidized bed conveyors may be captured in an air collection system for treatment. [0075] Rubber fines are removed from finishing water recovered from the dewatering screens and extruders for recycle or disposal. The finishing water with fines removed is recycled to the reslurry and chlorination unit with excess water purged from the process. The excess water will be further treated at the facility before final disposal. Additional antifouling and additives may be added to the recycled water to reduce fouling and control pH. The additives may include but not exclusively none, one or more of: calcium chloride, proprietary antifoulants, e.g. PETROFLO^TM or borate based buffers. [0076] For some embodiments involving chlorine regeneration, additives, including epoxidized soybean oil (also referred to as ESBO) and calcium stearate, may be added during the regenerative process. For example, ESBO may be added in the range of about 1 to about 2 phr in drying extruder 408 before or during the drying. Additionally or alternatively, as described above, calcium stearate may be added to the cement to the second neutralization unit 316, and/or may be added to the flash drum 324 to help the polymer from sticking to the equipment and to control the rubber particle size in the water slurry, and/or may be added to drying extruder 408 during the drying. [0077] In some embodiments, an additive, such as ESBO, may be added to stripper 338 and/or line 334. Recycle Stream Driers [0078] The diluent/monomers recycle stream (line 240 of FIG. 2) from the solvent replacement process section is dried using a combination of fixed bed alumina and chloride resistant molecular sieve driers 242 to remove moisture. The alumina driers will also remove oxygenates. The alumina and molecular sieve driers may be operated in series or in parallel or a combination of both, for example the operation is parallel molecular sieve driers with an alumina drier in series. The fixed bed alumina and chloride resistant molecular sieve driers 242 are taken out of service for regeneration when their water hold up capacity or oxygenate hold up capacity has been reached. The regeneration can include 1-3 depressurizations to deep vacuum to recover the hydrocarbon from the bed. The regeneration can include 1-3 warm pressurizations and depressurizations to maximize hydrocarbon removal before full regeneration. The regeneration can be carried out at 240 ^oC to 300 ^oC for molecular sieve driers and 190 ^oC to 250 ^oC for alumina driers. The regeneration gas humidity can be controlled by cooling the stream and removing moisture with refrigerated heat exchangers in advance of heating. The regeneration will include a steaming stage to minimize oil make up from the process for molecular sieves. Recovery and Recycle of Monomers from Isobutylene-based Polymers Using Distillation Processes [0079] The diluent/monomers stream (244 of FIG. 2) is sent to recycle towers to separate and recover diluent and monomers for reuse in the process. FIG.5 is a diagram 500 illustrating recycle and recovery of diluent and monomers. As shown in FIG. 5, first recycle tower 502 may be a single tower or 2 separate towers. The first recycle tower(s) 502 recover diluent and isobutylene in the overheads stream 504. The overheads stream is split with a portion (line 506) sent to a diluent recovery tower 508 where high purity diluent is recovered for use as catalyst diluent and a portion sent for recycle. The bottoms 528 of the diluent recovery tower 508 is combined with the other portion (line 510) of the recycle tower overheads and recycled to feed blend. The bottoms 512 of the first recycle tower 502 is sent to a second recycle tower 514. Overheads 516 of the second recycle tower are sent to diluent recovery tower 508. Bottoms 518 of the second recycle tower 514 containing isobutylene, isoprene, and some heavies is sent to an isobutylene recovery tower 520 where isobutylene is recovered overhead (line 522) for recycle. The bottoms 524 of the isobutylene recovery tower 520 is sent to an isoprene recovery tower 526 where isoprene is recovered overhead 530 for recycle. The bottoms 532 of the isoprene recovery tower 526 is purged from the process. The isobutylene and the isoprene recovery tower may be combined into a single distillation column. The distillate drum on the diluent recovery tower 508 can have an inerts venting system. This inerts venting system recovers diluent from the inerts stream and vents the residual ethylene/ethane by product from the aluminum alkyl catalyst and inerts from the process. The inerts recovery system has a distillation tower or a series of refrigeration heat exchangers to recover diluent. [0080] Antifoulants are injected into the isobutylene recovery tower 520 and isoprene recovery tower 526 to minimize fouling. Antifoulants may include a structure III stabilizer of the present disclosure and/or one or more suitable other antioxidants or antifoulants, including but not exclusively BHT (butylated hydroxytoluene) and proprietary antifoulants, e.g., PETROFLO^TM antifoulant. The isoprene recovery tower 526 trays and isobutylene recovery tower 520 trays may be electropolished to minimize fouling. Oxygen analyzers are fitted in the second recycle tower 514 overhead and diluent recovery tower 508 overhead. [0081] In some embodiments, concentration of isobutylene in the diluent recovery tower 508 overheads used for catalyst diluent is < 50 wtppm isobutylene and such as < 20 wtppm isobutylene. The recycle tower/diluent recovery tower temperatures can be set by the utilities temperature on the overhead condensers, typically cooling water or air. The tower pressures are set by the stream compositions based on the vapor pressure curves at the tower operating temperature. The second recycle tower 514 pressure can be about 800 kPag to about 1200 kPag, such as about 1000 kPag to about 1200 kPag. The diluent recovery tower 508 operating pressures can be about 800 kPag to about 1200 kPag, such as about 1000 kPag to about 1200 kPag. The isobutylene recovery tower 520 can use refrigerant in an overhead condenser to set a tower operating pressure of about 150 kPag to about 250 kPag. The isoprene recovery tower 526 can use refrigerant or cooling water in an overhead condenser and operates at a pressure of about 50 kPaa to about 150 kPaa to minimize fouling. The second recycle tower 514 and isobutylene recovery tower 520 can recover about 95% to about 99.999%, such as about 99.8 to about 99.9%, of the isobutylene in the feed. The isobutylene composition in the recycle streams is set by the reactor conversion. ADDITIONAL ASPECTS [0082] The present disclosure provides, among others, the following aspects, each of which may be considered as optionally including any alternate aspects. Clause 1. A process of forming a chlorobutyl elastomer, comprising: polymerizing, in a first reactor, a C₄ to C₇ isomonoolefin and at least one comonomer to obtain a C4 to C7 isomonoolefin derived elastomer; transferring, via a line, the C₄ to C₇ isomonoolefin derived elastomer to a second reactor; introducing O₂ at a flow rate of about 0.05 lbs/hr to about 2.5 lbs/hr (or 2.4 lbs/hr or 2.3 lbs/hr or 2.2 lbs/hr or 2.1 lbs/hr or 2 lbs/hr) to a chlorine source comprising a chlorinating agent to form a mixture comprising the chlorinating agent and the O2; and introducing, to the second reactor, the mixture comprising the chlorinating agent and the O₂ with the C₄ to C₇ isomonoolefin derived elastomer to form the chlorobutyl elastomer. Clause 2. The process of Clause 1, wherein the flow rate of O2 to the chlorine source is about 0.7 lbs/hr to about 1 lbs/hr. Clause 3. The process of Clauses 1 or 2, wherein the chlorinating agent is Cl2. Clause 4. The process of any of Clauses 1 to 3, wherein the chlorinating agent and the O₂ are each introduced as a gas phase with the C4 to C7 isomonoolefin derived elastomer. Clause 5. The process of any of Clauses 1 to 4, wherein the mixture comprising the chlorinating agent and the O2 comprises about 50 ppm to about 600 ppm of the O2 on mass/mass chlorine basis. Clause 6. The process of any of Clauses 1 to 5, wherein the mixture comprising the chlorinating agent and the O2 comprises about 275 ppm to about 325 ppm of the O2 on mass/mass chlorine basis. Clause 7. The process of any of Clauses 1 to 6, wherein introducing the mixture comprising the chlorinating agent and the O2 with the C4 to C7 isomonoolefin derived elastomer in the second reactor is performed at an amount of about 2 ppm to about 25 ppm of the O2 relative to the C₄ to C₇ isomonoolefin derived elastomer. Clause 8. The process of any of Clauses 1 to 7, wherein introducing the O2 to the chlorine source comprises introducing a mixture comprising the O₂ and a diluent to the chlorine source. Clause 9. The process of any of Clauses 1 to 8, wherein the mixture comprising the O2 and the diluent comprises the diluent in an amount of about 85 mol% to about 95 mol% and the O2 in amount of about 5 mol% to about 15 mol%. Clause 10. The process of any of Clauses 1 to 9, wherein the mixture comprising the O₂ and the diluent is introduced to the chlorine source at a flow rate of about 0.5 lbs/hr to about 12 lbs/hr. Clause 11. The process of any of Clauses 1 to 10, wherein the diluent is N2. Clause 12. The process of any of Clauses 1 to 11, wherein introducing the mixture comprising the chlorinating agent and the O2 to the second reactor comprises transferring the mixture through a line that directly fluidly couples the second reactor with the chlorine source. Clause 13. The process of any of Clauses 1 to 12, further comprising providing an effluent of the second reactor to a first neutralization unit and providing a neutralizing agent and water to the first neutralization unit. Clause 14. The process of any of Clauses 1 to 13, further comprising providing an effluent of the first neutralization unit to a second neutralization unit and providing a salt of stearic acid to the second neutralization unit. Clause 15. The process of any of Clauses 1 to 14, further comprising providing an effluent of the second neutralization unit to a flash drum and introducing calcium stearate and steam to the flash drum. Clause 16. The process of any of Clauses 1 to 15, further comprising providing an effluent of the flash drum to a stripper vessel and introducing steam to the stripper vessel. Clause 17. The process of any of Clauses 1 to 16, further comprising spraying water into a vapor space of each of the flash drum and the stripper vessel. Clause 18. The process of any of Clauses 1 to 17, wherein introducing the mixture comprising the chlorinating agent and the O2 with the C4 to C7 isomonoolefin derived elastomer is performed at a temperature of about 50 ^oC to about 75 ^oC. Clause 19. The process of any of Clauses 1 to 18, wherein the C4 to C7 isomonoolefin is isobutylene. Clause 20. The process of any of Clauses 1 to 19, wherein the at least one comonomer is isoprene. EXAMPLES Demonstration of Nitrox as Free-Radical Inhibitor [0083] It was decided to inject Nitrox into CB1066 utilizing metering facilities. The proposed injection rate was 5 - 10 lb/hr. Nitrox injection would be delayed until the symptoms of gray rubber appeared, to confirm background chemistries supported its formation without oxygen injection. [0084] Once gray rubber symptoms were observed, Nitrox was injected into the chlorine source. Nitrox was stopped within couple hours after the return of stable operation. This cycle was repeated to further confirm the background chemistry would form gray rubber. Eventually, after a fourth mild gray rubber event, the nitrox injection was continuously added for the remainder of the campaign at flowrates varying from 3 - 8 lb/hr. Depending upon production rate, this corresponded to an oxygen content of 250 - 1400 wppm of oxygen in the chlorine. This translates to about 15 - 35 wppm oxygen on a rubber basis going through chlorination. No gray rubber symptoms were observed during nitrox addition. [0085] Rheometer T90 results are shown in Table 1 for a portion of nitrox campaign. The initial results were consistent with commercial product at 12 minutes, then increased to off- specification 19 minutes, then dropped to 8 minutes later that same day. Comparable shifts were seen in ts2 and T50 but not modulus. Despite nitrox having no initial impact on rheometer, the anomaly warranted investigation, as the increase (19.42 minutes) appeared to correlate with change in nitrox flow. Product parameters like chlorine, calcium, moisture/water, and unsaturation were normal; these parameters typically have the biggest impact on cure. The product was resampled from the warehouse and the product came back on specification. [0086] After several weeks of gray-free rubber, the unit decided to further test the capability of nitrox by consuming two railcars that had previously produced gray rubber. One of these railcars had been produced by a supplier, whose chlorine has been particularly troublesome with gray rubber events in the past. Both railcars were run without issue avoiding further demurrage and disposal cost; and all product properties during the campaign were normal. Product Testing [0087] Samples of CB1066 made before and during the nitrox injection were tested for possible differences in aging appearance, structures, and delta Mooney. The no-nitrox control and the nitrox sample were from 0.3 wt% moisture re-process material to avoid downgrading a prime box. Table 1 – CB1066 Rheometer T90 Values Lab Result Sample Time 11.98 Day 17 22:35 Table 2 – Chlorobutyl Data Lab Sample Finished Chlorine Calcium BHT Volatiles Time Mooney Wt% Wt% Wt% Wt% [0088] The samples were aged 10 days at 80°C to determine if any color bodies might form that was not present in the control polymer. NMR test was conducted both before and after oven aging to confirm comparable microstructures. The appearance of the product after aging proved to be equivalent. There was comparable Mooney and Mooney Relaxation Index (MRI) delta. MRI is generated during the Mooney test by measuring the relaxation of the polymer. MRI is a surrogate test for the Gel Permeation Chromatography test that measures the molecular weight and molecular weight distribution of the polymer. Table 3 – CB1066 Oven Aging Mooney Growth Results MV 1+8 @ 125C Oven Age 80°C for 10 days Pre Nitrox Post Nitrox Pre-Nitrox Post-Nitrox g . Table 4 – NMR Microstructures of Aged Samples Batch Description Pre-Nitrox Pre-Nitrox Nitrox Nitrox Aged Control Control Addition 10 Table 5 Unit Olin Olin Chlorine Source 1 Chlorine Source 2 Freeport Plaquemin e an 9 19 .5 3 10 4 19 31 [0089] Overall, processes of the present disclosure can provide chlorobutyl elastomers having reduced soot content and reduced discoloration, providing millions of dollars of financial cost savings to a manufacturer and reduced or eliminated intermittent shutdowns of chlorobutyl rubber production. It has been discovered that introducing an oxygen source into the chlorine used to chlorinate butyl rubber cement can reduce or eliminate soot content and discoloration of the chlorobutyl elastomers formed. Oxygen can be introduced to a chlorination source at low amounts and flow rates which allows for higher flow rates of butyl rubber cement during chlorination processes, which increases the amount of chlorine available for use during the chlorination processes and improves throughput of chlorobutyl rubber formation. The oxygen can be introduced at the chlorine source, which can have the advantage of oxygen vapor and chlorine vapor mixing well (e.g., instead of oxygen gas and a liquid (hexane) or solid (butyl rubber cement)). It has also been discovered that lower quality chlorine sources (such as those of Table 5 above) can now be used in chlorination processes due to the introduction of even low levels of the oxygen to the chlorine source during chlorination of butyl rubber. [0090] In addition, oxygen can be provided by an oxygen source that is a mixture of oxygen and a diluent, such as nitrogen, which can be advantageous for controlled flaring for commercial manufacturing while still providing the benefit of reducing soot formation in a chlorobutyl rubber formed during a chlorination process. [0091] The phrases, unless otherwise specified, "consists essentially of" and "consisting essentially of" do not exclude the presence of other steps, elements, or materials, whether or not, specifically mentioned in this specification, so long as such steps, elements, or materials, do not affect the basic and novel characteristics of the present disclosure, additionally, they do not exclude impurities and variances normally associated with the elements and materials used. [0092] For the sake of brevity, only certain ranges are explicitly disclosed herein. However, ranges from any lower limit may be combined with any upper limit to recite a range not explicitly recited, as well as, ranges from any lower limit may be combined with any other lower limit to recite a range not explicitly recited, in the same way, ranges from any upper limit may be combined with any other upper limit to recite a range not explicitly recited. Additionally, within a range includes every point or individual value between its end points even though not explicitly recited. Thus, every point or individual value may serve as its own lower or upper limit combined with any other point or individual value or any other lower or upper limit, to recite a range not explicitly recited. [0093] All numerical values within the detailed description herein are modified by “about” the indicated value, and take into account experimental error and variations that would be expected by a person having ordinary skill in the art. [0094] All documents described herein are incorporated by reference herein, including any priority documents and or testing procedures to the extent they are not inconsistent with this text. As is apparent from the foregoing general description and the specific embodiments, while forms of the present disclosure have been illustrated and described, various modifications can be made without departing from the spirit and scope of the present disclosure. Accordingly, it is not intended that the present disclosure be limited thereby. Likewise, the term “comprising” is considered synonymous with the term “including” for purposes of United States law. Likewise whenever a composition, an element or a group of elements is preceded with the transitional phrase “comprising,” it is understood that we also contemplate the same composition or group of elements with transitional phrases “consisting essentially of,” “consisting of,” “selected from the group of consisting of,” or “is” preceding the recitation of the composition, element, or elements and vice versa. [0095] While the present disclosure has been described with respect to a number of embodiments and examples, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope and spirit of the present disclosure.

Claims

CLAIMS We claim: 1. A process of forming a chlorobutyl elastomer, comprising: polymerizing, in a first reactor, a C₄ to C₇ isomonoolefin and at least one comonomer to obtain a C4 to C7 isomonoolefin derived elastomer; transferring, via a line, the C₄ to C₇ isomonoolefin derived elastomer to a second reactor; introducing O₂ at a flow rate of about 0.05 lbs/hr to about 2.5 lbs/hr to a chlorine source comprising a chlorinating agent to form a mixture comprising the chlorinating agent and the O₂; and introducing, to the second reactor, the mixture comprising the chlorinating agent and the O2 with the C4 to C7 isomonoolefin derived elastomer to form the chlorobutyl elastomer.

2. The process of claim 1, wherein the flow rate of O2 to the chlorine source is about 0.1 lbs/hr to about 1 lbs/hr.

3. The process of claim 1, wherein the chlorinating agent is Cl₂.

4. The process of claim 1, wherein the chlorinating agent and the O₂ are each introduced as a gas phase with the C4 to C7 isomonoolefin derived elastomer.

5. The process of claim 1, wherein the mixture comprising the chlorinating agent and the O₂ comprises about 100 ppm to about 400 ppm of the O₂ on mass/mass chlorine basis.

6. The process of claim 5, wherein the mixture comprising the chlorinating agent and the O2 comprises about 140 ppm to about 300 ppm of the O2 on mass/mass chlorine basis.

7. The process of claim 1, wherein introducing the mixture comprising the chlorinating agent and the O₂ with the C₄ to C₇ isomonoolefin derived elastomer in the second reactor is performed at an amount of about 2 ppm to about 10 ppm of the O2 relative to the C4 to C7 isomonoolefin derived elastomer.

8. The process of claim 1, wherein introducing the O2 to the chlorine source comprises introducing a mixture comprising the O₂ and a diluent to the chlorine source.

9. The process of claim 8, wherein the mixture comprising the O₂ and the diluent comprises the diluent in an amount of about 85 mol% to about 95 mol% and the O2 in amount of about 5 mol% to about 15 mol%.

10. The process of claim 9, wherein the mixture comprising the O₂ and the diluent is introduced to the chlorine source at a flow rate of about 1 lbs/hr to about 12 lbs/hr.

11. The process of claim 10, wherein the diluent is N2.

12. The process of claim 1, wherein introducing the C4 to C7 isomonoolefin derived elastomer with the chlorinating agent further comprises introducing into the second reactor an emulsion comprising an oxidizing agent, water, and a surfactant.

13. The process of claim 1, further comprising providing an effluent of the second reactor to a first neutralization unit and providing a neutralizing agent and water to the first neutralization unit.

14. The process of claim 13, further comprising providing an effluent of the first neutralization unit to a second neutralization unit and providing a salt of stearic acid to the second neutralization unit.

15. The process of claim 14, further comprising providing an effluent of the second neutralization unit to a flash drum and introducing calcium stearate and steam to the flash drum.

16. The process of claim 15, further comprising providing an effluent of the flash drum to a stripper vessel and introducing steam to the stripper vessel.

17. The process of claim 16, further comprising spraying water into a vapor space of each of the flash drum and the stripper vessel.

18. The process of claim 1, wherein introducing the mixture comprising the chlorinating agent and the O2 with the C4 to C7 isomonoolefin derived elastomer is performed at a temperature of about 40 ^oC to about 75 ^oC.

19. The process of claim 1, wherein the C₄ to C₇ isomonoolefin is isobutylene.

20. The process of claim 19, wherein the at least one comonomer is isoprene.