A polyethylene homopolymer composition comprises: a first ethylene homopolymer having a density, d.sup.1 of from 0.930 to 0.975 g/cm.sup.3, a melt index, I.sub.2.sup.1 of from 0.01 to 10 g/10 min, and a molecular weight distribution, Mw/Mn of less than 2.5; and a second ethylene homopolymer having a density, d.sup.2 of from 0.945 to 0.980 g/cm.sup.3, a melt index, I.sub.2.sup.2 of at least 1.0 g/10 min, and a molecular weight distribution, M.sub.w/M.sub.n of less than 2.5; wherein melt index, I.sub.2.sup.2 of the second ethylene homopolymer is greater than the melt index, I.sub.2.sup.1 of the first ethylene homopolymer. The polyethylene homopolymer compositions which may be nucleated have a weight average molecular weight, M.sub.w of 75,000, a molecular weight distribution, M.sub.w/M.sub.n of less than 4.0 and may be usefully employed in molding applications, such as, for example, in compression molded closures.

A polyethylene homopolymer composition comprises: a first ethylene homopolymer having a density, d.sup.1 of from 0.930 to 0.975 g/cm.sup.3, a melt index, I.sub.2.sup.1 of from 0.01 to 10 g/10 min, and a molecular weight distribution, Mw/Mn of less than 2.5; and a second ethylene homopolymer having a density, d.sup.2 of from 0.945 to 0.980 g/cm.sup.3, a melt index, I.sub.2.sup.2 of at least 1.0 g/10 min, and a molecular weight distribution, M.sub.w/M.sub.n of less than 2.5; wherein melt index, I.sub.2.sup.2 of the second ethylene homopolymer is greater than the melt index, I.sub.2.sup.1 of the first ethylene homopolymer. The polyethylene homopolymer compositions which may be nucleated have a weight average molecular weight, M.sub.w of 75,000, a molecular weight distribution, M.sub.w/M.sub.n of less than 4.0 and may be usefully employed in molding applications, such as, for example, in compression molded closures.

Briefly, embodiments of systems and/or methods for synthesis of zinc oxide are described, including a chamber enclosure, a wafer substrate holder, a fluid handling system, and sequences for implementation.

A catalyst recovery system that includes a concentrated slurry production unit that concentrates a slurry extracted from a reactor main unit and continuously produces a concentrated slurry, a first discharge unit that discharges the concentrated slurry from the concentrated slurry production unit, a solidified slurry production unit that cools the concentrated slurry discharged from the concentrated slurry production unit, thereby solidifying the liquid medium within the concentrated slurry and producing a solidified slurry, and a recovery mechanism that recovers the solidified slurry from the solidified slurry production unit.

A catalyst recovery system that includes a concentrated slurry production unit that concentrates a slurry extracted from a reactor main unit and continuously produces a concentrated slurry, a first discharge unit that discharges the concentrated slurry from the concentrated slurry production unit, a solidified slurry production unit that cools the concentrated slurry discharged from the concentrated slurry production unit, thereby solidifying the liquid medium within the concentrated slurry and producing a solidified slurry, and a recovery mechanism that recovers the solidified slurry from the solidified slurry production unit.

A system for the integral chlorine dioxide production with relatively independent sodium chlorate electrolytic production and chlorine dioxide production is provided. The system may feed electrolyte solution into a solid-liquid filter, filtering out the crystal and eliminating sodium chloride and sodium dichromate. The sodium chlorate crystal may be fed into a chlorine dioxide generator after dissolving, while sodium chloride and sodium dichromate solution separately return to electrolyzer for electrolysis process. Sodium chloride may be constantly formed as a by-product in the chlorine dioxide production unit, and solution containing the sodium chloride is withdrawn from the generator and, after filtration, washing and dissolution, recycled back to sodium chlorate production unit. This way, there is no need of sodium chloride make-up.

A system for the integral chlorine dioxide production with relatively independent sodium chlorate electrolytic production and chlorine dioxide production is provided. The system may feed electrolyte solution into a solid-liquid filter, filtering out the crystal and eliminating sodium chloride and sodium dichromate. The sodium chlorate crystal may be fed into a chlorine dioxide generator after dissolving, while sodium chloride and sodium dichromate solution separately return to electrolyzer for electrolysis process. Sodium chloride may be constantly formed as a by-product in the chlorine dioxide production unit, and solution containing the sodium chloride is withdrawn from the generator and, after filtration, washing and dissolution, recycled back to sodium chlorate production unit. This way, there is no need of sodium chloride make-up.

A method for the control of a plant (10) for the production in continuous of a polymer, wherein the plant (10) comprises at least one reactor (11) fed with at least a first monomer and a second monomer, a first stripper (12), a second stripper (17), a third stripper (18), at least one recycling vat (13) of the fine products, measurement equipment (14) and a control system comprising distributed control devices (15) controllable by at least one electronic processing and control unit (16) based on a plurality of control variables, the control method comprising the following steps: collecting data comprising recipe parameters, laboratory analysis results and predefined coefficients stored in a database (40); collecting the data measured by the measurement equipment (14); determining, by means of a first calculation module (20) a production potentiality value of the at least one reactor (11); determining, by means of a second calculation module (21) the polymer concentration in the at least one reactor (11), in the first stripper (12) and in the at least one recycling vat of the fine products (13); determining, by means of a third calculation module (22) the flow-rate of oil for feeding the second stripper (17); determining, by means of a fourth calculation module (23), the flow-rate of the chain terminator (TERM) for feeding the at least one reactor (11), controlling the plant (10) on the basis of the plurality of control variables.

A method for the control of a plant (10) for the production in continuous of a polymer, wherein the plant (10) comprises at least one reactor (11) fed with at least a first monomer and a second monomer, a first stripper (12), a second stripper (17), a third stripper (18), at least one recycling vat (13) of the fine products, measurement equipment (14) and a control system comprising distributed control devices (15) controllable by at least one electronic processing and control unit (16) based on a plurality of control variables, the control method comprising the following steps: collecting data comprising recipe parameters, laboratory analysis results and predefined coefficients stored in a database (40); collecting the data measured by the measurement equipment (14); determining, by means of a first calculation module (20) a production potentiality value of the at least one reactor (11); determining, by means of a second calculation module (21) the polymer concentration in the at least one reactor (11), in the first stripper (12) and in the at least one recycling vat of the fine products (13); determining, by means of a third calculation module (22) the flow-rate of oil for feeding the second stripper (17); determining, by means of a fourth calculation module (23), the flow-rate of the chain terminator (TERM) for feeding the at least one reactor (11), controlling the plant (10) on the basis of the plurality of control variables.

There is described a process for preparing a biodegradable polyester from an aromatic dicarboxylic acid, an aliphatic dicarboxylic acid and a diol where in a first reaction step the aromatic acid is esterified with the diol, and in a second reaction step the aliphatic acid is added to the reaction mixture. Furthermore, there is described an apparatus for carrying out this process.