Process for preparing blends of bitumen having known stability properties

Abstract

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.

What is claimed is: 
     
         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.