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US 7,252,753 B2Granted
Dielectric fluids and processes for making same
AssigneeChevron U.S.A. Inc.
InventorsJohn M. Rosenbaum, Nadine L. Yenni, Joseph M. Pudlak
Life of this patent
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Abstract
Dielectric fluids comprising oil fractions derived from highly paraffinic wax are provided. Further provided are processes for making these dielectric fluids comprising oil fractions derived from highly paraffinic wax. The dielectric fluids are useful as insulating and cooling mediums in new and existing power and distribution electrical apparatus, such as transformers, regulators, circuit breakers, switchgear, underground electrical cables, and attendant equipment.
Claims35
A process for producing a dielectric fluid comprising:
- a) providing a highly paraffinic wax;
- b) hydroisomerizing the highly paraffinic wax using a shape selective intermediate pore size molecular sieve comprising a noble metal hydrogenation component under conditions of about 600° F. to about 750° F. to provide an isomerized oil;
- and
- c) fractionating the isomerized oil to provide at least one oil fraction having a T90 boiling point ≧950° F., a kinematic viscosity between about 6 cSt and about 20 cSt at 100° C., and a pour point of ≧−14° C., wherein the oil comprises ≧10 weight % molecules with monocycloparaffinic functionality, ≦3 weight % molecules with multicycloparaffinic functionality, and less than 0.30 weight % aromatics
- d) optionally blending the oil fraction with an effective amount of one or more additives;
- and
- e) isolating a dielectric fluid having a dielectric breakdown of ≧25 kV as measured by ASTM D877.
4 more elements
A process for producing a dielectric fluid comprising:
- a) performing a Fischer-Tropsch synthesis to provide a product stream;
- b) isolating from the product stream a substantially paraffinic wax feed;
- c) hydroisomerizing the substantially paraffinic waxy feed using a shape selective intermediate pore size molecular sieve comprising a noble metal hydrogenation component under conditions of about 600° F. to about 750° F.;
- d) isolating an isomerized oil;
- e) fractionating the isomerized oil to provide one or more oil fractions having a T90 boiling point ≧950° F., a kinematic viscosity between about 6 cSt and about 16 cSt at 100° C., and a pour point of ≧−14° C.;
- wherein the lubricant base oil comprises ≧10 weight % molecules with monocycloparaffinic functionality, ≦3 weight % molecules with multicycloparaffinic functionality, and less than 0.30 weight % aromatics;
- f) optionally blending the one or more oil fractions with an effective amount of one or more additives;
- and
- g) isolating a dielectric fluid having a dielectric breakdown of ≧25 kV as measured by ASTM D877.
6 more elements
Dependencies are inferred from the claim text.