US 5,746,973 A · Method for reducing odorant depletion

Abstract

Odorant depletion is reduced by passivating the internal surface of LP-gas transportation and storage vessels by the addition of passivating agents comprising mixtures of corrosion inhibitors such as phosphate esters, fatty amines, poly amides, imidazolines, poly imidazolines, quaternary amines, poly quats, dimer acids, trimer acids, polymeric acids, ethoxylated fatty amines, ethoxylated polyamides, ethoxylated alcohols and mixtures thereof in one or more solvents. In a preferred embodiment, the passivating agents contain one or more phosphate esters defined by the equation: R--X--C.sub.m H.sub.2m O).sub.n !.sub.k --PO(OH).sub.(3-k) where; R is an alkyl group containing 4 to 18 carbon atoms or an alkylaryl group comprising an aryl group selected from the group consisting of phenol, diphenol, and mixtures thereof, and an alkyl group containing 4 to 18 carbon atoms; X is selected from the group consisting of a carboxyl group (--COO--), oxygen (--O--), a secondary amine group (--NH--) and mixtures thereof; m is an integer having a value from about 2 to about 4; n is an integer having a value from about 4 to about 20; and k is an integer having a value from 1 to 2 and one or more fatty amines, poly amides, imidazolines, poly imidazolines, quaternary amines, poly quats, dimer acids, trimer acids, polymeric acids, ethoxylated fatty amines, ethoxylated polyamides, ethoxylated alcohols or mixtures thereof and one or more solvents.

Claims22

Dependent claims

A method for reducing odorant depletion during transfer and storage of liquefied petroleum gas comprising the steps of

(a) completely filling a liquefied petroleum gas transfer or storage vessel with a passivating agent so that all interior surfaces of said vessel come in contact with said passivating agent, said passivating agent comprising one or more phosphate esters, the one or more phosphate esters defined by the equation:
R--X--C.sub.m H.sub.2m O).sub.n !.sub.k --PO(OH).sub.(3-k)
where;
R is an alkyl group containing 4 to 18 carbon atoms or an alkylaryl group comprising an aryl group selected from the group consisting of phenol, diphenol, and mixtures thereof, and an alkyl group containing 4 to 18 carbon atoms;
X is selected from the group consisting of a carboxyl group (--COO--), oxygen (--O--), a secondary amine group (--NH--), sulfur (--S--);
m is an integer having a value from about 2 to about 4;
n is an integer having a value from about 1 to about 20;
and
k is an integer having a value from 1 to 2
and one or more additional ingredients selected from the group consisting of fatty amines, poly amides, imidazolines, poly imidazolines, quaternary amines, poly quats, dimmer acids, trimmer acids, polymeric acids, ethoxylated fatty amines, and ethoxylated polyamides, and one or more solvents;
(b) draining said passivating agent from said vessel;
and
(c) evacuating said vessel prior to the introduction of said liquefied petroleum gas into said vessel.

10 more elements

A method for reducing odorant depletion during transfer and storage of liquefied petroleum gas comprising the step of

(a) adding a passivating agent that is dispersible or soluble in propane directly to said liquefied petroleum gas in a transportation or storage vessel along with said odorant in an amount sufficient to provide a concentration of said passivating agent in the range of up to about 250 ppm (v/v), said passivating agent comprising one or more phosphate esters, said one or more phosphate esters defined by the equation:
R--X--C.sub.m H.sub.2m O).sub.n !.sub.k --PO(OH).sub.(3-k)
where;
R is an alkyl group containing 4 to 18 carbon atoms or an alkylaryl group comprising an aryl group selected from the group consisting of phenol, diphenol, and mixtures thereof, and an alkyl group containing 4 to 18 carbon atoms;
X is selected from the group consisting of a carboxyl group (--COO--), oxygen (--O--), a secondary amine group (--NH--), sulfur (--S--);
m is an integer having a value from about 2 to about 4;
n is an integer having a value from about 1 to about 20;
and
k is an integer having a value from 1 to 2
and one or more additional ingredients selected from the group consisting of fatty amines, poly amides, imidazolines, poly imidazolines, quaternary amines, poly quats, dimmer acids, trimmer acids, polymeric acids, ethoxylated fatty amines, and ethoxylated polyamides, and one or more solvents.

7 more elements

Dependencies are inferred from the claim text.

Method for reducing odorant depletion

Life of this patent

Method for reducing odorant depletion

Life of this patent

Abstract

Claims22