Abstract: Methods for purifying an acetonitrile waste stream are provided. An exemplary method for purifying an acetonitrile waste stream includes generating an acetonitrile waste stream during oligonucleotide synthesis and fractionating the acetonitrile waste stream to produce a single overhead fraction. The method includes condensing the single overhead fraction to produce a condensed single overhead fraction and contacting the condensed single overhead fraction with an adsorbent material to produce an acetonitrile stream that comprises an amount of an impurity that is reduced relative to the acetonitrile waste stream.

Abstract: Methods and systems for purifying an acetonitrile waste stream and methods for synthesizing an oligonucleotide using a purified acetonitrile waste stream are provided. An exemplary method for purifying an acetonitrile waste stream includes providing an acetonitrile waste stream and fractionating the acetonitrile waste stream to produce a single overhead fraction. The method includes condensing the single overhead fraction to produce a condensed single overhead fraction and contacting the condensed single overhead fraction with an adsorbent to produce an acetonitrile stream that comprises an amount of at least one impurity that is reduced relative to the acetonitrile waste stream.

Abstract: The present invention relates, in part, to HFO and/or HCFO based working compositions exhibiting chemical and thermal stability in high temperature heat transfer systems. In certain aspects, the HFO and/or HCFO compounds may be represented by formula I wherein R1, R2 R3, and R4 are each independently selected from the group consisting of H, F, Cl, Br, C1-C6 alkyl, C1-C6 fluoroalkyl, at least C6 aryl (preferably C6-C15 aryl), C6-C15 fluoroaryl, at least C3 cycloalkyl (preferably C6-C12 cycloalkyl), C6-C12 fluorocycloalkyl, C6-C15 alkylaryl, and C6-C15 fluoroalkylaryl, wherein the compound contains at least one F atom. Such working fluids are provided with at least one stabilizer to minimize HFO and/or HCFO degradation.

Abstract: This invention involves the use of a more effective adsorbent to dehydrate ethanol. The most common use for the ethanol is an additive to gasoline. The preferred adsorbent is a type 3A adsorbent that has been ion exchanged with potassium at a level of about 0.6. Surprisingly, this adsorbent has a significantly improved resistance to damage by water upset events.

Abstract: The invention comprises a temperature swing adsorption system for providing dry air to an air brake system. More particularly, there is provided a desiccant wheel upstream of the air compressor to dry air prior to its compression.

Abstract: A method is provided for production of low dust adsorbents and catalysts. A thin layer of metal oxide derived from a colloidal solution of the oxide is deposited on the adsorbent or catalyst particle, which greatly improves the physical properties of the particle with regards to attrition and dust formation while retaining the adsorbent and catalytic properties of the particle. The method is applicable to a variety of porous refractory oxides. For example, treatment with colloidal silica improves greatly the physical stability of alumina adsorbents.

Abstract: An adsorbent and a process are disclosed for drying gases in a pressure swing dryer. The adsorbent comprises a pre-formed alumina particle having a surface area of about 250 to 550 m2 &mgr;g with a thin layer of colloidal silica disbursed on the surface of the pre-formed alumina particle. Surprisingly the thin layer of colloidal silica does not interfere with the drying properties of the pre-formed alumina particle, while significantly improving the physical properties of the pre-formed alumina particle.

Abstract: A method is provided for production of low dust adsorbents and catalysts. A thin layer of metal oxide derived from a colloidal solution of the oxide is deposited on the adsorbent or catalyst particle, which greatly improves the physical properties of the particle with regards to attrition and dust formation while retaining the adsorbent and catalytic properties of the particle. The method is applicable to a variety of porous refractory oxides. For example, treatment with colloidal silica improves greatly the physical stability of alumina adsorbents.

Abstract: An adsorbent and a process are disclosed for drying gases in a pressure swing dryer. The adsorbent comprises a pre-formed alumina particle with a thin layer of colloidal silica disbursed on the surface of the preformed alumina particle.

Abstract: Difluoromethane (R-32) is of current interest as a partial replacement for chlorodifluoromethane (R-22) refrigerant heretofore widely used in vapor compression refrigeration systems. R-32 has, however, proved to be more reactive than is desirable with the zeolite A adsorbent-desiccant compositions used in such systems to prevent corrosion and freeze-up problems. The potassium cation form of a zeolite A molecular sieve—with at least 60 percent of the sodium cations replaced with potassium ions, agglomerated with a clay binder, and pore-reduced to essentially exclude the adsorption of R-32 having essentially no reactivity with difluoromethane, and having a surface ratio of silicon to aluminum of less than about 1.7 mol/mol as determined by X-ray photoelectron spectroscopy—has been found to be an effective desiccant for refrigerants comprising difluoromethane.

Abstract: Difluoromethane (R-32) is of current interest as a partial replacement for chlorodifluoromethane (R-22) refrigerant heretofore widely used in vapor compression refrigeration systems. R-32 has, however, proved to be more reactive than is desirable with the zeolite A adsorbent-desiccant compositions used in such systems to prevent corrosion and freeze-up problems. The potassium cation form of a zeolite A molecular sieve—with at least 60 percent of the sodium cations replaced with potassium ions, agglomerated with a clay binder, and pore-reduced to essentially exclude the adsorption of R-32 having essentially no reactivity with difluoromethane, and having a surface ratio of silicon to aluminum of less than about 1.7 mol/mol as determined by X-ray photoelectron spectroscopy—has been found to be an effective desiccant for refrigerants comprising difluoromethane.

Abstract: Difluoromethane (R-32) is of current interest as a partial replacement for chlorodifluoromethane (R-22) refrigerant heretofore widely used in vapor compression refrigeration systems. R-32 has, however, proved to be more reactive than is desirable with the zeolite A adsorbent-desiccant compositions used in such systems to prevent corrosion and freeze-up problems. The potassium cation form of a zeolite A molecular sieve--with at least 60 per cent of the sodium cations replaced with potassium ions, agglomerated with a clay binder and pore-reduced to essentially exclude the adsorption of R-32, and having essentially no reactivity with difluoromethane--has been found to be an effective desiccant for refrigerants comprising difluoromethane.

Abstract: Novel, hollow, low-density agglomerates for use in sealed insulating glass windows to adsorb water vapor, and optionally organic materials, present in the cavity between the two glazings. These agglomerates provide sufficient but not excessive amounts of zeolitic and other adsorbents when used to fill all portions of the spacer tube located at the peripheral sides of the double glazed unit, thereby greatly facilitating the filling of such spacer tubes and the fabrication of the overall unit.

Abstract: A process and apparatus for the recovery and purification of a contaminated refrigerant withdrawn from a refrigeration or refrigerant recovery system which employs a compressor and an adsorbent selective for the adsorption of halogenated hydrocarbons. The adsorbent is selected from the group consisting of silicalite, faujasites, steamed and rare earth exchanged zeolite Y, mordenite, ZSM-5 and mixtures thereof, and more particularly the group consisting of a low cerium rare earth exchanged zeolite Y-84, a low cerium rare earth exchanged zeolite LZ-210, Breck Structure Six, ECR-32, and mixtures thereof. A significant increase in the capacity of these adsorbents over conventional adsorbents combined with the use of novel process steps to recover, purify and return a purified refrigerant to the refrigeration system result in significant cost savings at reduced risk of release of halogenated hydrocarbons to the environment.

Abstract: Novel, hollow, low-density agglomerates for use in sealed insulating glass windows to adsorb water vapor, and optionally organic materials, present in the cavity between the two adsorbents when used to fill all portions of the spacer tube located at the peripheral sides of the double glazed unit, thereby greatly facilitating the filling of such spacer robes and the fabrication of the overall unit.

Abstract: Layered adsorbent-substrate composites are prepared by methods comprising heating the surface of an aluminum substrate, contacting the surface of the substrate with a slurry containing the adsorbent and a binder, and heating the coatings to form hardened surfaces which can have excellent adsorption and mechanical properties and have a variety of uses such as adsorbents in automobile mufflers.

Abstract: A process and apparatus for the recovery and purification of a contaminated refrigerant withdrawn from a refrigeration or refrigerant recovery system which employs a compressor and an adsorbent selective for the adsorption of halogenated hydrocarbons. The adsorbent is selected from the group consisting of silicalite, faujasites, steamed and rare earth exchanged zeolite Y, mordenite, ZSM-5 and mixtures thereof, and more particularly the group consisting of a low cerium rare earth exchanged zeolite Y-84, a low cerium rare earth exchanged zeolite LZ-210, Breck Structure Six, ECR-32, and mixtures thereof. A significant increase in the capacity of these adsorbents over conventional adsorbents combined with the use of novel process steps to recover, purify and return a purified refrigerant to the refrigeration system result in significant cost savings at reduced risk of release of halogenated hydrocarbons to the environment.

Abstract: Difluoromethane (R32) is of current interest as a partial replacement for chlorodifluoromethane (R22) refrigerant heretofore widely used in vapor compression refrigeration systems. R32 has, however, proved to be more reactive than is desirable with the zeolite A adsorbent-desiccant compositions used in such systems to prevent corrosion and freeze-up problems. The sodium cation form of a zeolite having the crystal structure of zeolite B is found to be an effective adsorbent for that purpose and to be significantly less reactive with the R32.

Abstract: Layered adsorbent-substrate composites are prepared by methods comprising heating the surface of an aluminum substrate, contacting the surface of the substrate with a slurry containing the adsorbent and a binder, and heating the coatings to form hardened surfaces which can have excellent adsorption and mechanical properties and have a variety of uses such as adsorbents in automobile mufflers and a desiccants in multiple pane windows.

Abstract: Layered adsorbent-substrate composites are prepared by methods comprising heating the surface of an aluminum substrate, contacting the surface of the substrate with a slurry containing the adsorbent and a binder, and heating the coatings to form hardened surfaces which can have excellent adsorption and mechanical properties and have a variety of uses such as adsorbents in automobile mufflers and as desiccants in multiple pane windows.