Alkyl sorbitan emulsion compositions for fuel cell reformer start-up
AssigneeExxonMobil Research and Engineering Company
InventorsRamesh Varadaraj, Paul Joseph Berlowitz
Life of this patent
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Abstract
The present invention relates to emulsion compositions for starting a reformer of a fuel cell system. In particular, the invention includes emulsion compositions comprising hydrocarbon fuel, water and alkyl sorbitan surfactants for starting a reformer of a fuel cell system.
Claims23
In a fuel cell system comprising a reformer to produce a hydrogen containing gas for use in a fuel cell stack, the improvement comprising:
- feeding to the reformer, at start-up, an emulsion composition comprising,
- at least 40 wt % of hydrocarbon,
- from 30 to 60 wt % of water, and
- from 0.01 to 5 wt % of at least one surfactant selected from the group consisting of alkyl sorbitan esters and alkoxylated alkyl sorbitan esters and mixtures thereof, and
- represented by the respective formulae
- 4
- wherein R is an alkyl group of 5 to 18 carbons,
- R′ is H or (M—O)n—H where n is an integer from about 2 to 20 and the total number of (M—O)n—H groups per molecule is from 2 to 60,
- M is CH2—CH2, CH2—CH2—CH2, CH2—CH—CH3, CH2—CH2—CH2—CH2, CH2—CH—(CH3)—CH2 or mixtures thereof.
A method to prepare a bicontinuous emulsion comprising a coexisting mixture of at least 80 vol % of a water-in-hydrocarbon macro emulsion and from 1 to 20 vol % of an hydrocarbon-in-water micro emulsion the method comprising:
- mixing at mixing energy in the range of 0.15×1031 5 to 0.15×1031 3 kW/liter of fluid,
- at least 40 wt % of hydrocarbon,
- from 30 to 60 wt % of water, and
- from 0.01 to 5 wt % of at least one surfactant selected from the group consisting of alkyl sorbitan esters and alkoxylated alkyl sorbitan esters and mixtures thereof, and
- represented by the respective formula,
- 5
- wherein R is an alkyl group of 5 to 18 carbons, R′ is H or (M—O)n—H where n is an integer from about 2 to 20 and the
- total number of (M—O)n—H groups per molecule is from 2 to 60,
- M is CH2—CH2, CH2—CH2—CH2, CH2—CH—CH3, CH2—CH2—CH2—CH2, CH2—CH—(CH3)—CH2 or mixtures thereof.
A bicontinuous emulsion comprising a coexisting mixture of at least 80 vol % of a water-in-hydrocarbon macro emulsion and from 1 to 20 vol % of an hydrocarbon-in-water×1031 5 to 0.15 ×10−3 kW/liter of fluid,
- at least 40 wt % of hydrocarbon,
- from 30 to 60 wt % of water, and
- from 0.01 to 5 wt % of at least one surfactant selected from the group consisting of alkyl sorbitan esters and alkoxylated alkyl sorbitan esters and mixtures thereof, and
- represented by the respective formula,
- 6
- wherein R is an alkyl group of 5 to 18 carbons, R′ is H or (M—O)n—H where n is an integer from about 2 to 20 and the total number of (M—O)n—H groups per molecule is from 2 to 60,
- M is CH2—CH2, CH2—CH2—CH2, CH2—CH—CH3, CH2—CH2—CH2—CH2, CH2—CH—(CH3)—CH2 or mixtures thereof.
A method for preventing corrosion of a metal surface comprising, contacting the metal surface with an emulsion comprising:
- at least 40 wt % of hydrocarbon,
- from 30 to 60 wt % of water, and
- from 0.01 to 5 wt % of at least one surfactant selected from the group consisting of alkyl sorbitan esters and alkoxylated alkyl sorbitan esters and mixtures thereof, and
- represented by the respective formula
- 7
- wherein R is an alkyl group of 5 to 18 carbons, R′ is H or (M—O)n—H where n is an integer from about 2 to 20 and the total number of (M—O)n—H groups per molecule is from 2 to 60,
- M is CH2—CH2, CH2—CH2—CH2, CH2—CH—CH3, CH2—CH2—CH2—CH2, CH2—CH—(CH3)—CH2 or mixtures thereof, for a time period ranging from 1 second to 3 hours, and at temperatures in the range of −20° C. to 100° C.
Dependencies are inferred from the claim text.