US4618348A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Combustion of viscous hydrocarbons
Assignee: PETROLEUM FERMENTATIONS NV A NETHERLAND ANTILLES CORP
•
Filing: 1983-11-02
•
Granted: 1986-10-21
•
Expires: 2003-11-02
Abstract
Abstract Methods and compositions are provided to facilitate the transporation and combustion of highly viscous hydrocarbons by forming reduced viscosity hydrocarbon-in-water emulsions, and in particular, bioemulsifier-stabilized hydrocarbon-in-water emulsions.
Inventors
- 👤 Michael E. Hayes
- 👤 Kevin R. Hrebenar
- 👤 Patricia L. Murphy
- 👤 Laurence E. Futch, Jr.
- 👤 James F. Deal, III
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:39
CPC Classifications
C; C09; C09K; C09K23/00; C09K23/017; C10; C10L; C10L1/00; C10L1/32; C10L1/328; Y; Y10; Y10S; Y10S516/00; Y10S516/01; Y10S516/06
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
267 words
A method for utilizing viscous hydrocarbons as combustible fuels comprising: (A) forming a hydrocarbosol using a surfactant package in a proportion of about 1:100 to about 1:20,000 by weight based on hydrocarbon, (1) said surfactant package comprising (a) at least one water-soluble surfactant, an effective amount of which surfactant promotes emulsification of a hydrocarbon with API gravity of about 20° API or less, viscosity of about 100 centipoise or greater at 150° F., paraffin content of about 50% by weight or less and aromatic content of about 40% by weight or greater into an aqueous phase to form a hydrocarbon-in-water emulsion wherein the proportion of hydrocarbon to aqueous phase is about 90:10 by volume or less, the viscosity of which emulsion is reduced by at least a factor of about 10 compared to the viscosity of the hydrocarbon; and (b) at least one water-soluble bioemulsifier, being a microboally-derived substance which predominantly resides at hydrocarbon/water interfaces to substantially surround hydrocarbon droplets in hydrocarbon-in-water emulsions, an effective amount of which bioemulsifier stabilizes a hydrocarbon-in-water emulsion formed with a hydrocarbon as in (a) by maintaining viscosity reduced by at least a factor of about 10 for a period of at least about a day under static conditions, (2) said hydrocarbosol (a) comprising a hydrocarbon characterized by an API gravity of about 20° API or less, viscosity of 100 centipoise or greater at 150° F., paraffin content of about 50% by weight or less and aromatic content of about 40% by weight or greater; and (b) having a hydrocarbon:water ratio of about 70:30 by volume; and (B) burning the resultant hydrocarbosol.
Claim 2
Independent Claim
267 words
A method for utilizing viscous hydrocarbons as combustible fuels comprising: (A) forming a hydrocarbosol using a surfactant package in a proportion of about 1:100 to about 1:20,000 by weight based on hydrocarbon, (1) said surfactant package comprising (a) at least one water-soluble surfactant, an effective amount of which surfactant promotes emulsification of a hydrocarbon with API gravity of about 20° API or less, viscosity of about 100 centipoise or greater at 150° F., paraffin content of about 50% by weight or less and aromatic content of about 40% by weight or greater into an aqueous phase to form a hydrocarbon-in-water emulsion wherein the proportion of hydrocarbon to aqueous phase is about 90:10 by volume or less, the viscosity of which emulsion is reduced by at least a factor of about 10 compared to the viscosity of the hydrocarbon; and (b) at least one water-soluble bioemulsifier, being a microboally-derived substance which predominantly resides at hydrocarbon/water interfaces to substantially surround hydrocarbon droplets in hydrocarbon-in-water emulsions, an effective amount of which bioemulsifier stabilizes a hydrocarbon-in-water emulsion formed with a hydrocarbon as in (a) by maintaining viscosity reduced by at least a factor of about 10 for a period of at least about a day under static conditions, (2) said hydrocarbosol (a) comprising a hydrocarbon characterized by an API gravity of about 20° API or less, viscosity of 100 centipoise or greater at 150° F., paraffin content of about 50% by weight or less and aromatic content of about 40% by weight or greater; and (b) having a hydrocarbon:water ratio of about 70:30 by volume; and (B) burning the resultant hydrocarbosol.
Claim 3
Independent Claim
235 words
A method for utilizing viscous hydrocarbons as combustible fuels comprising: (A) forming a hydrocarbosol using a surfactant package in a proportion of about 1:100 to about 1:20,000 by weight based on hydrocarbon, (1) said surfactant package comprising (a) from about 1% to about 50% by weight of α-emulsan; and (b) from about 50% to about 99% by weight of a water-soluble nonionic surfactant selected from the group consisting of (i) an ethoxylated monoalkyl or dialkyl phenol represented by the formula RC 6 H 4 (OC 2 H 4 ) n OH wherein R represents an alkyl group containing from about 8 to about 12 carbon atoms add wherein n represents the number of ethoxy groups ranging from about 1 to about 100 and (ii) an ethoxylated alcohol represented by the formula R(OC 2 H 4 ) n OH wherein R represents a branched or linear aliphatic group containing from about 6 to about 18 carbon atoms and wherein n represents the number of ethoxy groups ranging from about 2 to about 100, (2) said hydrocarbosol (a) comprising a hydrocarbon characterized by an API gravity of about 20° API or less, viscosity of 100 centipoise or greater at 150° F., paraffin content of about 50% by weight or less and aromatic content of about 40% by weight or greater; and (b) having a hydrocarbon:water ratio of about 70:30 by volume; and (B) burning the resultant hydrocarbosol.
Claim 4
Independent Claim
235 words
A method for utilizing viscous hydrocarbons as combustible fuels comprising: (A) forming a hydrocarbosol using a surfactant package in a proportion of about 1:100 to about 1:20,000 by weight based on hydrocarbon, (1) said surfactant package comprising (a) from about 1% to about 50% by weight of α-emulsan; and (b) from about 50% to about 99% by weight of a water-soluble nonionic surfactant selected from the group consisting of (i) an ethoxylated monoalkyl or dialkyl phenol represented by the formula RC 6 H 4 (OC 2 H 4 ) n OH wherein R represents an alkyl group containing from about 8 to about 12 carbon atoms add wherein n represents the number of ethoxy groups ranging from about 1 to about 100 and (ii) an ethoxylated alcohol represented by the formula R(OC 2 H 4 ) n OH wherein R represents a branched or linear aliphatic group containing from about 6 to about 18 carbon atoms and wherein n represents the number of ethoxy groups ranging from about 2 to about 100, (2) said hydrocarbosol (a) comprising a hydrocarbon characterized by an API gravity of about 20° API or less, viscosity of 100 centipoise or greater at 150° F., paraffin content of about 50% by weight or less and aromatic content of about 40% by weight or greater; and (b) having a hydrocarbon:water ratio of about 70:30 by volume; and (B) burning the resultant hydrocarbosol.
Claim 5
Independent Claim
252 words
A method for utilizing viscous hydrocarbons as combustible fuels comprising: (A) forming a hydrocarbosol using a surfactant package in a proportion of about 1:100 to about 1:20,000 by weight based on hydrocarbon, (1) said surfactant package comprising (a) from about 1% to about 50% by weight of α-emulsan; and (b) from about 50% to about 99% by weight of a combination of (i) a water-soluble nonionic ethoxylated monoalkyl or dialkyl phenol represented by the formula RC 6 H 4 (OC 2 H 4 ) n OH wherein R represents an alkyl group containing from about 8 to about 12 carbon atoms and wherein n represents the number of ethoxy groups ranging from about 1 to about 100 and (ii) a water-soluble anionic ethoxylated or nonethoxylated alcohol sulfate represented by the formula R(OC 2 H 4 ) n OSO 3 M wherein R represents an aliphatic group containing from about 6 to about 16 carbon atoms, n represents the number of ethoxy groups ranging from about 0 to about 4, and M is ammonium, sodium, potassium, calcium or triethanolamine, said combination being in a proportion of about 1:1 by weight, (2) said hydrocarbosol (a) comprising a hydrocarbon characterized by an API gravity of about 20° API or less, viscosity of 100 centipoise or greater at 150° F., paraffin content of about 50% by weight or less and aromatic content of about 40% by weight or greater; and (b) having a hydrocarbon:water ratio of about 70:30 by volume; and (B) burning the resultant hydrocarbosol.
Claim 6
Independent Claim
252 words
A method for utilizing viscous hydrocarbons as combustible fuels comprising: (A) forming a hydrocarbosol using a surfactant package in a proportion of about 1:100 to about 1:20,000 by weight based on hydrocarbon, (1) said surfactant package comprising (a) from about 1% to about 50% by weight of α-emulsan; and (b) from about 50% to about 99% by weight of a combination of (i) a water-soluble nonionic ethoxylated monoalkyl or dialkyl phenol represented by the formula RC 6 H 4 (OC 2 H 4 ) n OH wherein R represents an alkyl group containing from about 8 to about 12 carbon atoms and wherein n represents the number of ethoxy groups ranging from about 1 to about 100 and (ii) a water-soluble anionic ethoxylated or nonethoxylated alcohol sulfate represented by the formula R(OC 2 H 4 ) n OSO 3 M wherein R represents an aliphatic group containing from about 6 to about 16 carbon atoms, n represents the number of ethoxy groups ranging from about 0 to about 4, and M is ammonium, sodium, potassium, calcium or triethanolamine, said combination being in a proportion of about 1:1 by weight, (2) said hydrocarbosol (a) comprising a hydrocarbon characterized by an API gravity of about 20° API or less, viscosity of 100 centipoise or greater at 150° F., paraffin content of about 50% by weight or less and aromatic content of about 40% by weight or greater; and (b) having a hydrocarbon:water ratio of about 70:30 by volume; and (B) burning the resultant hydrocarbosol.
Claim 7
Independent Claim
136 words
A method for utilizing viscous hydrocarbons as combustible fuels comprising: (A) forming a hydrocarbosol using a surfactant package in a proportion of about 1:100 to about 1:20,000 by weight based on hydrocarbon, (1) said surfactant package comprising (a) about 15% by weight of α-emulsan; (b) about 42.5% by weight of ethoxylated monononyl phenol with about 40 ethoxy groups; and (c) about 42.5% by weight of ethoxylated monooctyl phenol with about 40 ethoxy groups, (2) said hydrocarbosol (a) comprising a hydrocarbon characterized by an API gravity of about 20° API or less, viscosity of 100 centipoise or greater at 150° F., paraffin content of about 50% by weight or less and aromatic content of about 40% by weight or greater and (b) having a hydrocarbon:water ratio of about 70:30 by volume; and (B) burning the resultant hydrocarbosol.
Claim 8
Independent Claim
136 words
A method for utilizing viscous hydrocarbons as combustible fuels comprising: (A) forming a hydrocarbosol using a surfactant package in a proportion of about 1:100 to about 1:20,000 by weight based on hydrocarbon, (1) said surfactant package comprising (a) about 15% by weight of α-emulsan; (b) about 42.5% by weight of ethoxylated monononyl phenol with about 40 ethoxy groups; and (c) about 42.5% by weight of ethoxylated monooctyl phenol with about 40 ethoxy groups, (2) said hydrocarbosol (a) comprising a hydrocarbon characterized by an API gravity of about 20° API or less, viscosity of 100 centipoise or greater at 150° F., paraffin content of about 50% by weight or less and aromatic content of about 40% by weight or greater and (b) having a hydrocarbon:water ratio of about 70:30 by volume; and (B) burning the resultant hydrocarbosol.
Claim 9
Independent Claim
138 words
A method for utilizing viscous hydrocarbons as combustible fuels, comprising (A) forming a hydrocarbosol using a surfactant package in a proportion of about 1:100 to about 1:20,000 by weight based on hydrocarbon, (1) said surfactant package comprising about 15% by weight of α-emulsan, about 42.5% by weight of an ethoxylated monononyl phenol with about 40 ethoxy groups and about 42.5% by weight of an ammonium salt of poly(3)ethoxy C 12 -C 14 linear primary alcohol sulfate, (2) said hydrocarbosol (a) comprising a hydrocarbon characterized by API gravity of about 20° API or less, viscosity of 100 centipoise or greater at 150° F., paraffin content of about 50% by weight or less and aromatic content of about 40% by weight or greater and (b) having a hydrocarbon:water ratio of about 70:30 by volume; and (B) burning the resultant hydrocarbosol.
Claim 10
Independent Claim
138 words
A method for utilizing viscous hydrocarbons as combustible fuels, comprising (A) forming a hydrocarbosol using a surfactant package in a proportion of about 1:100 to about 1:20,000 by weight based on hydrocarbon, (1) said surfactant package comprising about 15% by weight of α-emulsan, about 42.5% by weight of an ethoxylated monononyl phenol with about 40 ethoxy groups and about 42.5% by weight of an ammonium salt of poly(3)ethoxy C 12 -C 14 linear primary alcohol sulfate, (2) said hydrocarbosol (a) comprising a hydrocarbon characterized by API gravity of about 20° API or less, viscosity of 100 centipoise or greater at 150° F., paraffin content of about 50% by weight or less and aromatic content of about 40% by weight or greater and (b) having a hydrocarbon:water ratio of about 70:30 by volume; and (B) burning the resultant hydrocarbosol.
Claim 11
Independent Claim
139 words
A method for utilizing viscous hydrocarbons as combustible fuels, comprising (A) forming a hydrocarbosol using a surfactant package in a proportion of about 1:100 to about 1:20,000 by weight based on hydrocarbon, (1) said surfactant package comprising about 15% by weight α-emulsan and about 85% by weight of an ethoxylated alkyl phenol selected from the group consisting of ethoxylated monononyl phenol with about 40 ethoxy groups and ethoxylated monooctyl phenol with about 40 ethoxy groups, (2) said hydrocarbosol (a) comprising a hydrocarbon characterized by API gravity of about 20° API or less, viscosity of about 100 centipoise or greater at 150° F., paraffin content of about 50% by weight or less, and an aromatic content of about 40% by weight or greater and (b) having a hydrocarbon:water ratio of about 70:30 by volume and (B) burning the resultant hydrocarbosol.
Claim 12
Independent Claim
139 words
A method for utilizing viscous hydrocarbons as combustible fuels, comprising (A) forming a hydrocarbosol using a surfactant package in a proportion of about 1:100 to about 1:20,000 by weight based on hydrocarbon, (1) said surfactant package comprising about 15% by weight α-emulsan and about 85% by weight of an ethoxylated alkyl phenol selected from the group consisting of ethoxylated monononyl phenol with about 40 ethoxy groups and ethoxylated monooctyl phenol with about 40 ethoxy groups, (2) said hydrocarbosol (a) comprising a hydrocarbon characterized by API gravity of about 20° API or less, viscosity of about 100 centipoise or greater at 150° F., paraffin content of about 50% by weight or less, and an aromatic content of about 40% by weight or greater and (b) having a hydrocarbon:water ratio of about 70:30 by volume and (B) burning the resultant hydrocarbosol.
Claim 13
Independent Claim
70 words
A method for utilizing viscous hydrocarbons as combustible fuels, comprising (A) forming a hydrocarbon-in-water emulsion using an effective amount of a surfactant package comprising at least one water-soluble surfactant, said hydrocarbon-in-water emulsion (1) comprising a hydrocarbon characterized by a viscosity of about 100 centipoise or greater at 150° F. and (2) having a hydrocarbon:water ratio from about 60:40 to about 90:10 by volume; and (B) burning the resultant hydrocarbon-in-water emulsion.
Claim 14
Independent Claim
70 words
A method for utilizing viscous hydrocarbons as combustible fuels, comprising (A) forming a hydrocarbon-in-water emulsion using an effective amount of a surfactant package comprising at least one water-soluble surfactant, said hydrocarbon-in-water emulsion (1) comprising a hydrocarbon characterized by a viscosity of about 100 centipoise or greater at 150° F. and (2) having a hydrocarbon:water ratio from about 60:40 to about 90:10 by volume; and (B) burning the resultant hydrocarbon-in-water emulsion.
Claim 15
Independent Claim
97 words
A method for utilizing viscous hydrocarbons as combustible fuels, comprising: (A) forming a hydrocarbon-in-water emulsion using an effective amount of a surfactant package comprising at least one water-soluble surfactant, said hydrocarbon-in-water emulsion (1) comprising a hydrocarbon characterized by API gravity of about 20° API or less, viscosity of about 100 centipoise or greater at 150° F., paraffin content of about 50% by weight or less, and an aromatic content of about 40% by weight or greater and (2) having a hydrocarbon:water ratio from about 60:40 to about 90:10 by volume, and (B) burning the resultant hydrocarbon-in-water emulsion.
Claim 16
Independent Claim
97 words
A method for utilizing viscous hydrocarbons as combustible fuels, comprising: (A) forming a hydrocarbon-in-water emulsion using an effective amount of a surfactant package comprising at least one water-soluble surfactant, said hydrocarbon-in-water emulsion (1) comprising a hydrocarbon characterized by API gravity of about 20° API or less, viscosity of about 100 centipoise or greater at 150° F., paraffin content of about 50% by weight or less, and an aromatic content of about 40% by weight or greater and (2) having a hydrocarbon:water ratio from about 60:40 to about 90:10 by volume, and (B) burning the resultant hydrocarbon-in-water emulsion.
Claim 17
Independent Claim
72 words
A method for utilizing viscous hydrocarbons as combustible fuels, comprising (A) forming a hydrocarbosol using an effective amount of a surfactant package comprising at least one water-soluble surfactant and at least one water-soluble bioemulsifier, said hydrocarbosol (1) comprising a hydrocarbon characterized by a viscosity of 100 centipoise or greater at 150° F. and (2) having a hydrocarbon:water ratio from about 60:40 to about 90:10 by volume; and (B) burning the resultant hydrocarbosol.
Claim 18
Independent Claim
72 words
A method for utilizing viscous hydrocarbons as combustible fuels, comprising (A) forming a hydrocarbosol using an effective amount of a surfactant package comprising at least one water-soluble surfactant and at least one water-soluble bioemulsifier, said hydrocarbosol (1) comprising a hydrocarbon characterized by a viscosity of 100 centipoise or greater at 150° F. and (2) having a hydrocarbon:water ratio from about 60:40 to about 90:10 by volume; and (B) burning the resultant hydrocarbosol.
Claim 19
Independent Claim
100 words
A method for utilizing viscous hydrocarbons as combustible fuels, comprising: (A) forming a hydrocarbosol using an effective amount of a surfactant package comprising at least one water-soluble surfactant and at least one water-soluble bioemulsifier, said hydrocarbosol (1) comprising a hydrocarbon characterized by API gravity of about 20° API or less, viscosity of about 100 centipoise or greater at 150° F., paraffin content of about 50% by weight or less, and an aromatic content of about 40% by weight or greater and (2) having a hydrocarbon:water ratio from about 60:40 to about 90:10 by volume and (B) burning the resultant hydrocarbosol.
Claim 20
Independent Claim
100 words
A method for utilizing viscous hydrocarbons as combustible fuels, comprising: (A) forming a hydrocarbosol using an effective amount of a surfactant package comprising at least one water-soluble surfactant and at least one water-soluble bioemulsifier, said hydrocarbosol (1) comprising a hydrocarbon characterized by API gravity of about 20° API or less, viscosity of about 100 centipoise or greater at 150° F., paraffin content of about 50% by weight or less, and an aromatic content of about 40% by weight or greater and (2) having a hydrocarbon:water ratio from about 60:40 to about 90:10 by volume and (B) burning the resultant hydrocarbosol.
Claim 21
Dependent Claim
144 words
The method of claim 7 wherein: (a) the surfactant package is used in a proportion from about 1:100 to about 1:20,000 by weight based on hydrocarbon; (b) said surfactant package comprises a nonionic ethoxylated monoalkyl or dialkyl phenol represented by the formula RC 6 H 4 (OC 2 H 4 ) n OH wherein R represents an alkyl group containing from about 8 to about 12 carbon atoms and wherein n represents the number of ethoxy groups ranging from about 1 about 100; and (c) said hydrocarbon-in-water emulsion (i) comprises a hydrocarbon with API gravity of about 20° API or less, viscosity of about 100 centipoise or greater at 150° F., paraffin content of about 50% by weight or less and aromatic content of about 40% by weight or greater and (ii) has a hydrocarbon:water ratio from about 60:40 to about 90:10 by volume.
Claim 22
Dependent Claim
209 words
The method of claim 7 wherein: (a) the surfactant package is used in a proportion from about 1:100 to about 1:20,000 by weight based on hydrocarbon; (b) said surfactant package comprises in about a 1:1 proportion by weight a nonionic ethoxylated monoalkyl or dialkyl phenol represented by the formula RC 6 H 4 (OC 2 H 4 ) n OH wherein R represents an alkyl group containing from about 8 to about 12 carbon atoms and wherein n represents the number of ethoxy groups ranging from about 1 about 100 and an anionic ethoxylated or nonethoxylated alcohol sulfate represented by the formula R(OC 2 H 4 ) n OSO 3 M wherein R represents an aliphatic group containing from about 6 to 16 carbon atoms, n represents the number of ethoxy groups ranging from about 0 to about 4 and M is ammonium, sodium, potassium, calcium or triethanolamine; and (c) said hydrocarbon-in-water emulsion i) comprises a hydrocarbon with API gravity of about 20° API or less, viscosity of about 100 centipoise or greater at 150° F., paraffin content of about 50% by weight or less and aromatic content of about 40% by weight or greater and ii) has a hydrocarbon:water ratio from about 60:40 to about 90:10 by volume.
Claim 23
Dependent Claim
37 words
The method of claim 11 or 12 wherein the nonionic ethoxylated monoalkyl phenol is selected from the group consisting of ethoxylated monononyl phenol with about 40 ethoxy groups and ethoxylated monooctyl phenol with about 40 ethoxy groups.
Claim 24
Dependent Claim
41 words
The method of claim 12 wherein the nonionic ethoxylated monoalkyl phenol is an ethoxylated monononyl phenol with about 40 ethoxy groups and the anionic ethoxylated alcohol sulfate is an ammonium salt of poly(3)ethoxy C 12 -C 14 linear primary alcohol sulfate.
Claim 25
Dependent Claim
41 words
The method of claim 5, 6, 7, 9, 11, 12, 1, 2, 3, 4, 8 or 10 wherein the hydrocarbon-in-water emulsion is formed in an aqueous phase containing a methanol/water mixture with a methanol:water ratio of 45:55 by volume or less.
Claim 26
Dependent Claim
25 words
The method of claim 5, 6, 7, 9, 11, 12, 1, 2, 3, 4, 8 or 10 wherein the hydrocarbon is a residual fuel oil.
Claim 27
Dependent Claim
27 words
The method of claim 5, 6, 7, 9, 11, 12, 1, 2, 3, 4, 8 or 10 wherein the hydrocarbon is a Number 6 residual fuel oil.
Claim 28
Dependent Claim
25 words
The method of claim 5, 6, 7, 9, 11, 12, 1, 2, 3, 4, 8 or 10 wherein the hydrocarbon is a viscous crude oil.
Claim 29
Dependent Claim
14 words
The method of claim 18 wherein the viscous crude oil is Boscan crude oil.
Claim 30
Dependent Claim
15 words
The method of claim 18 wherein the viscous crude oil is Texas fireflood crude oil.
Claim 31
Dependent Claim
31 words
The method of claim 18 wherein the viscous crude oil is selected from: the group consisting of Jibaro crude oil, Bartra crude oil, El Jobo crude oil and Kansas crude oil.
References Cited (Backward Citations)
US3006354A
Cited
US2981683A
Cited
US3487844A
Cited
US3352109A
Cited
US3490237A
Cited
US3519006A
Cited
US3425429A
Cited
US3380531A
Cited
US3490471A
Cited
US3630953A
Cited
US3467195A
Cited
US3876391A
Cited
US4002435A
Cited
US3941692A
Cited
US3902869A
Cited
US3958915A
Cited
US3943954A
Cited
US4084940A
Cited
US4158551A
Cited
US4086164A
Cited
US4046519A
Cited
US4134415A
Cited
US4192767A
Cited
US4392865A
Cited
US4162143A
Cited
US4246919A
Cited
US4249554A
Cited
US4273611A
Cited
US4239052A
Cited
US4246920A
Cited
US4234689A
Cited
US4311829A
Cited
US4276094A
Cited
US4395354A
Cited
US4230801A
Cited
US4311830A
Cited
US4311831A
Cited
US4311832A
Cited
US4265264A
Cited
US4315755A
Cited
US4285356A
Cited
US4287902A
Cited
US4333488A
Cited
US4477258A
Cited
US4445908A
Cited
US4382802A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-10-20 | 1990-04-21 | 1990-10-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-10-20 | 1994-04-21 | 1994-10-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-10-20 | 1998-04-21 | 1998-10-21 | $7700.00 | Window Closed / Lapsed |