Abstract: Drag reduction of hydrocarbon fluids flowing through pipelines of various lengths is improved by polyolefin drag reducer dispersions or dispersions using bi- or multi-modal particle size distributions. Drag reducers having larger particle sizes dissolve more slowly than drag reducers having smaller particle sizes. By using at least bi-modal particle size distributions drag reduction can be distributed more uniformly over the length of the pipeline where smaller sized particles dissolve sooner or earlier in the pipeline and larger sized particles dissolve later or further along the pipeline.

Abstract: A process for continuously producing a polymer drag reducing agent (DRA) is described. The process concerns mixing a monomer and a catalyst in at least one continuously stirred tank reactor (CSTR) to form a mixture. The mixture is continuously injected into a volume continuously formed by a thermoplastic material, such as polyethylene. The thermoplastic material is periodically sealed off to form a temporary container or bag. The monomer is permitted to polymerize in the temporary container to form polymer. In one non-limiting embodiment, the polymerization in the bag takes place within an inert, circulating fluid that accelerates heat transfer. The polymer and the temporary container are then ground together, preferably at non-cryogenic temperatures, to produce a particulate polymer drag reducing agent. In one preferred, non-limiting embodiment, the grinding or pulverizing occurs in the presence of at least one solid organic grinding aid.

Abstract: A process for producing fine particulate polymer drag reducing agent (DRA) without cryogenic temperatures, is described. The grinding or pulverizing of polymer, such as poly(alpha-olefin) may be achieved by the use of at least one solid organic grinding aid and at least one liquid grinding aid. In one non-limiting embodiment of the invention, the grinding is conducted at ambient temperature. Examples of a solid organic grinding aid include ethene/butene copolymer particles, paraffin waxes and solid alcohols. An example of a suitable liquid grinding aid includes a blend of glycol, water and isopropyl alcohol. Particulate DRA may be produced at a size of about 500 microns or less. Use of an attrition mill is preferred.

Abstract: Temperature control and efficient heat transfer are important to producing high quality polymer drag reducing agents from alpha-olefin and/or other monomers. Many polymerization reactions are exothermic, and controlling or minimizing the exotherm combined with low reaction temperatures yields high molecular weight and, for poly(alpha-olefins), high quality drag reducing agent polymers. It has been found that a shell and tube heat exchanger-type reactor, with the inner tubes hosting the reaction mixture and a coolant circulating through the shell side gives good temperature control. The use of appropriate release agents helps to keep the inner reaction chambers from building up any polymer residue. These reactors can be operated in a continuous filling and harvesting mode to facilitate the continuous production of polymer drag reducing agent and related formulations.

Abstract: A process for producing polymer drag reducing agent (DRA) slurries without cryogenic temperatures or conventional grinding is described. The homogenizing or size reduction of polymer, such as poly(alpha-olefins), may be achieved by the use of granulated polymer and at least one liquid, non-solvent for the polymer DRA. In one non-limiting embodiment of the invention, the homogenizing is conducted at ambient temperature. Examples of suitable non-solvents include water and non-aqueous non-solvents including, but not necessarily limited to, alcohols, glycols, glycol ethers, ketones, and esters; having from 2-6 carbon atoms, and combinations thereof. The polymeric DRA may be homogenized to an average particle size of about 600 microns or less.

Abstract: A process for producing polymer drag reducing agent (DRA) slurries without cryogenic temperatures or conventional grinding is described. The homogenizing or size reduction of polymer, such as poly(alpha-olefins), may be achieved by the use of granulated polymer and at least one liquid, non-solvent for the polymer DRA. In one non-limiting embodiment of the invention, the homogenizing is conducted at ambient temperature. Examples of suitable non-solvents include water and non-aqueous non-solvents including, but not necessarily limited to, alcohols, glycols, glycol ethers, ketones, and esters; having from 2-6 carbon atoms, and combinations thereof. The polymeric DRA may be homogenized to an average particle size of about 600 microns or less.

Abstract: Temperature control and efficient heat transfer are important to producing high quality polymer drag reducing agents from alpha-olefin and/or other monomers. Many polymerization reactions are exothermic, and controlling or minimizing the exotherm combined with low reaction temperatures yields high molecular weight and, for poly(alpha-olefins), high quality drag reducing agent polymers. It has been found that a shell and tube heat exchanger-type reactor, with the inner tubes hosting the reaction mixture and a coolant circulating through the shell side gives good temperature control. The use of appropriate release agents helps to keep the inner reaction chambers from building up any polymer residue. These reactors can be operated in a continuous filling and harvesting mode to facilitate the continuous production of polymer drag reducing agent and related formulations.

Abstract: A process for continuously producing a polymer drag reducing agent (DRA) is described. The process concerns mixing a monomer and a catalyst in at least one continuously stirred tank reactor (CSTR) to form a mixture. The mixture is continuously injected into a volume continuously formed by a thermoplastic material, such as polyethylene. The thermoplastic material is periodically sealed off to form a temporary container or bag. The monomer is permitted to polymerize in the temporary container to form polymer. In one non-limiting embodiment, the polymerization in the bag takes place within an inert, circulating fluid that accelerates heat transfer. The polymer and the temporary container are then ground together, preferably at non-cryogenic temperatures, to produce a particulate polymer drag reducing agent. In one preferred, non-limiting embodiment, the grinding or pulverizing occurs in the presence of at least one solid organic grinding aid.

Abstract: A process for producing fine particulate polymer drag reducing agent (DRA) by without cryogenic temperatures, is described. The grinding or pulverizing of polymer, such as poly(alpha-olefin) may be achieved by the use of at least one solid organic grinding aid and at least one liquid grinding aid. In one non-limiting embodiment of the invention, the grinding is conducted at ambient temperature. Examples of a solid organic grinding aid include ethene/butene copolymer particles, paraffin waxes and solid alcohols. An example of a suitable liquid grinding aid includes a blend of glycol, water and isopropyl alcohol. Particulate DRA may be produced at a size of about 500 microns or less. Use of an attrition mill is preferred.

Abstract: A process for continuously producing a polymer drag reducing agent (DRA) is described. The process concerns mixing a monomer and a catalyst in at least one continuously stirred tank reactor (CSTR) to form a mixture. The mixture is continuously injected into a volume continuously formed by a thermoplastic material, such as polyethylene. The thermoplastic material is periodically sealed off to form a temporary container or bag. The monomer is permitted to polymerize in the temporary container to form polymer. In one non-limiting embodiment, the polymerization in the bag takes place within an inert, circulating fluid that accelerates heat transfer. The polymer and the temporary container are then ground together, preferably at non-cryogenic temperatures, to produce a particulate polymer drag reducing agent. In one preferred, non-limiting embodiment, the grinding or pulverizing occurs in the presence of at least one solid organic grinding aid.

Abstract: Low viscosity, high concentration drag reducing agents may be prepared by slowly adding a liquid, non-solvent (e.g. isopropyl alcohol) for a drag reducing polymer (e.g. a polyalphaolefin) to a mixture of the polymer and the solvent (e.g. kerosene) in which the polymer is dissolved. When enough non-solvent is added, the polymer precipitates into fine particles. The supernatant mixture of solvent and non-solvent is then removed from the precipitated polymer slurry concentrate. Further solvent contained in the slurry concentrate may be removed by evaporation or further extraction with the liquid, non-solvent. The resulting slurry concentrate dissolves rapidly in flowing hydrocarbon streams to reduce the drag therein, and gives exceptionally good drag reducing results at low concentrations. Additionally, no injection probes or other special equipment is required to introduce the drag reducing slurry into the hydrocarbon stream, nor is grinding of the polymer necessary to form a suitable DRA slurry.

Abstract: In the process of producing polyisocyanates by(a) condensing an alkyl-N-phenylcarbamate having 1 to 3 carbons in the alkyl moiety with formaldehyde, paraformaldehyde a formaldehyde forming compound such as trioxane in the presence of an acid to produce a condensate containing a mixture of diphenylmethane dicarbamates and polymethylene polyphenyl carbamates with by-product N-benzyl compounds, rearranging said N-benzyl compounds in said condensate with acid catalyst to obtain a pyrolysis feed mixture containing a mixture of diphenylmethane dicarbamates and polymethylene polyphenyl carbamates with by-product amine and amine salts, and(b) thermally decomposing the carbamate moieties in the pyrolysis feed mixture to isocyanate moieties to produce a polyisocyanate mixture of diphenylmethane diisocyanates and polymethylene polyphenyl isocyanates,the improvement comprises increasing the percent isocyanate content of said polyisocyanates by prior to step (b) removing the amine and amine salt by-products by extracting

Abstract: A catalyst composition for the polymerization, including oligomerization and codimerization, of olefins is provided by combining (A) zirconium, (B) a monophosphine electron donor ligand, and (C) a Lewis acid-reducing agent, in molar ratios of (B) to (A) of about 1 to 10:1 and (C) to (A) of about 1 to 40:1. Preferred catalyst components are zirconium acetylacetonate, triphenylphosphine or tri-n-butylphosphine and ethylaluminum sesquichloride. The catalyst composition of this invention may be employed in the dimerization of olefins such as propylene as well as in codimerization reactions, such as the preparation of heptenes from propylene and butenes.