PROCESS FOR PREPARING BLENDS OF BITUMEN HAVING KNOWN STABILITY PROPERTIES
Bitumen may be prepared by mixing at least two bitumen feed streams to prepare a bitumen product stream; analyzing the feed streams and the product stream to determine a stability index for each using a Bitumen Asphaltene Stability Index Test; and when the index value for the bitumen product stream is less than about 90% of the weighted average index value for the feed streams, modifying the product stream to achieve a stability index value that is at least 90% of the weighted average index value for the feed streams.
1 . A method of preparing bitumen comprising mixing at least two bitumen feed streams to prepare a bitumen product stream; analyzing the feed streams and the product stream to determine a stability index for each using a Bitumen Asphaltene Stability Index Test; and when the index value for the bitumen product stream is less than about 90% of the weighted average index value for the feed streams, modifying the product stream to achieve a stability index value that is at least 90% of the weighted average index value for the feed streams.
2 . The method of claim 1 wherein the at least two bitumen feed streams are a virgin bitumen,
3 . The method of claim 2 wherein at least one of the two bitumen feed streams is a bitumen recycle stream.
4 . The method of claim 3 wherein the bitumen recycle stream is selected from the group consisting of recycled asphalt recovered from roads or parking lots, recycled roofing shingles, recycle roofing membranes, and combinations thereof.
5 . The method of claim 4 wherein the bitumen recycle stream has been melted and treated to remove fillers and gravel.
6 . The method of claim 1 wherein at least one of the bitumen feed streams is a very heavy hydrocarbon.
7 . The method of claim 1 wherein the bitumen product stream has a too low stability index, employing remedial efforts to raise the bitumen product stream's stability index.
8 . The method of claim 7 wherein the remedial effort is introducing a stabilizing additive to the bitumen product stream.
9 . The method of claim 8 wherein the stabilizing additive is prepared from a formulation including a first component selected from the group consisting of (alkoxylated)-(di or tri)-alkyl phenol-aldehyde (amine) resins; α-Olefin-maleic anhydride co-polymers and grafted polymers including half ester/amide and full ester/amide derivatives; and combinations thereof.
10 . The method of claim 9 wherein the stabilizing additive is prepared from a formulation including a second component which is a synergist and selected from the group consisting of polyamines, amidoamines, imidazolines, and combinations thereof.
11 . The method of claim 8 wherein the stabilizing additive is introduced at a concentration of from about 0.1 to about 10 wt % of the bitumen product stream.
12 . The method of claim 1 wherein where the bitumen product stream is being transported or moved and it would be desirable to avoid having to reheat the bitumen upon its arrival.
13 . The method of claim 12 wherein the bitumen product stream is being transported using a rail car or a tank car.
14 . A method of preparing bitumen comprising modeling a bitumen production process by admixing samples of at least two bitumen feed streams to produce a model bitumen production stream; analyzing the feed streams and the product stream to determine a stability index for each using a Bitumen Asphaltene Stability Index Test; and when the index value for the bitumen product stream is less than about 90% of the weighted average index value for the feed streams, repeat the process using different feed mix ratios and/or bitumen stabilizing additives until a stable bitumen product stream model is produced; and then using the model to control the bitumen production process.
15 . The method of claim 14 wherein the bitumen stabilizing additive is employed.
16 . The method of claim 15 wherein the bitumen stabilizing additive is prepared from a formulation including a first component selected from the group consisting of (alkoxylated)-(di or tri)-alkyl phenol-aldehyde (amine) resins; α-Olefin-maleic anhydride co-polymers and grafted polymers including half ester/amide and full ester/amide derivatives; and combinations thereof.
17 . The method of claim 16 wherein the bitumen stabilizing additive is prepared from a formulation including a second component which is a synergist and selected from the group consisting of polyamines, amidoamines, imidazolines, and combinations thereof.
18 . The method of claim 17 wherein the bitumen stabilizing additive is introduced at a concentration of from about 0.1 to about 10 wt % of the bitumen product stream.
19 . The method of claim 14 wherein the invention is employed within a refinery.
20 . The method of claim 19 wherein the method is employed to prevent production of bitumen that, unmodified, would be too viscous to move through a unit without the use of solvents or manual washouts.