The present invention relates to a method of marking a petroleum hydrocarbon by adding to and uniformly mixing with said petroleum hydrocarbon a chemical marker of general formula (I)

##STR00001## wherein two of the residues R.sup.1-R.sup.10 are independently of each other selected from C.sub.1-C.sub.4-alkoxy, and eight of the residues R.sup.1-R.sup.10 are independently of each other selected from the group consisting of hydrogen and C.sub.1-C.sub.4-alkyl, as well as to a composition of a petroleum hydrocarbon comprising a petroleum hydrocarbon and at least one chemical marker of general formula (I). The presence and concentration of the chemical marker of general formula (I) in the composition of the petroleum hydrocarbon can be advantageously determined by laser ionization coupled with mass spectrometry or by laser ionization coupled with ion mobility spectrometry.

A working fluid composition for a refrigerating machine, containing: a refrigerant containing trifluoroiodometbane; and a refrigerating machine oil containing a polyol ester and a hindered phenol compound, wherein a content of the hindered phenol compound is 0.6 to 10% by mass based on a total amount of the refrigerating machine oil.

An aspect of the present invention provides a refrigerating machine oil containing an ester-based base oil, at least one epoxy compound selected from an alkyl glycidyl ether and an aryl glycidyl ether, and a phenol-based antioxidant, wherein a content of the epoxy compound is 0.7% by mass or more based on a total amount of the refrigerating machine oil, and the refrigerating machine oil is used with a refrigerant containing trifluoroiodomethane.

There is provided a base oil additive comprising an ester of a palmitic acid, a method of forming the base oil additive, a lubricating oil composition comprising the base oil additive and a method of modifying a property of a base oil.

The present invention addresses the problem of providing a lubricating oil composition having excellent heat resistance (suppression of discoloration in heating) and tackiness while maintaining excellent viscosity properties of a lubricating oil composition using a ricinolic acid polymer. The present invention provides a copolymer (B) containing structural units (a) derived from ricinolic acid, structural units (b) derived from an aliphatic dicarboxylic acid and structural units (c) derived from a diol having 2 to 10 carbon atoms in a specific ratio and having a specific intrinsic viscosity, and provides a lubricating oil composition containing a base oil and the copolymer (B) and having a mass ratio (mass of (A) /mass of (B)) of the base oil (A) to the copolymer (B) of 60/40 to 99.5/0.5.

Systems and methods are provided for block operation during lubricant and/or fuels production from deasphalted oil. During block operation, a deasphalted oil and/or the hydroprocessed effluent from an initial processing stage can be split into a plurality of fractions. The fractions can correspond, for example, to feed fractions suitable for forming a light neutral fraction, a heavy neutral fraction, and a bright stock fraction, or the plurality of fractions can correspond to any other convenient split into separate fractions. The plurality of separate fractions can then be processed separately in the process train (or in the sweet portion of the process train) for forming fuels and/or lubricant base stocks. The separate processing can allow for selection of conditions for forming lubricant fractions, such as bright stock fractions, that have a cloud point that is lower than the pour point.

Systems and methods are provided for block operation during lubricant and/or fuels production from deasphalted oil. During block operation, a deasphalted oil and/or the hydroprocessed effluent from an initial processing stage can be split into a plurality of fractions. The fractions can correspond, for example, to feed fractions suitable for forming a light neutral fraction, a heavy neutral fraction, and a bright stock fraction, or the plurality of fractions can correspond to any other convenient split into separate fractions. The plurality of separate fractions can then be processed separately in the process train (or in the sweet portion of the process train) for forming fuels and/or lubricant base stocks.

Systems and methods are provided for block operation during lubricant and/or fuels production from deasphalted oil. During block operation, a deasphalted oil and/or the hydroprocessed effluent from an initial processing stage can be split into a plurality of fractions. The fractions can correspond, for example, to feed fractions suitable for forming a light neutral fraction, a heavy neutral fraction, and a bright stock fraction, or the plurality of fractions can correspond to any other convenient split into separate fractions. The plurality of separate fractions can then be processed separately in the process train (or in the sweet portion of the process train) for forming fuels and/or lubricant base stocks. The initial stage can optionally include a bulk hydrotreating catalyst to assist with increasing the space velocity in the initial stage.

Systems and methods are provided for block operation during lubricant and/or fuels production from deasphalted oil. During block operation, a deasphalted oil and/or the hydroprocessed effluent from an initial processing stage can be split into a plurality of fractions. The fractions can correspond, for example, to feed fractions suitable for forming a light neutral fraction, a heavy neutral fraction, and a bright stock fraction, or the plurality of fractions can correspond to any other convenient split into separate fractions. The plurality of separate fractions can then be processed separately in the process train (or in the sweet portion of the process train) for forming fuels and/or lubricant base stocks. This can allow for formation of unexpected base stock compositions.

The present invention relates to the field of lubricant, and specifically provides a lubricant composition and its preparation method and use. The lubricant composition comprises a base oil and rubber particles having radiation crosslinked structure dispersed therein, wherein the base oil is continuous phase and the rubber particles are dispersed phase. The viscosity of the lubricant composition of the present invention can be effectively adjusted as temperature changes. As compared with the lubricant composition comprising chemically crosslinked rubber particles, it has a lower viscosity at low temperatures and a higher viscosity at high temperatures, and has a relatively high viscosity index, which can meet the application requirements at the temperature above 200? C. In addition, the lubricant composition of the present invention also has excellent antiwear and friction-reducing properties.