Blending tar sands to provide feedstocks for hot water process

• US 4,474,616 A
• Filed: 12/13/1983
• Issued: 10/02/1984
• Est. Priority Date: 12/13/1983
• Status: Expired due to Fees

• Current Assignee: Petro-Canada Exploration Incorporated
• Original Assignee: Canada-Cities Service Limited, Gulf Canada Ltd. (ConocoPhillips), Esso Resources Canada Ltd. (Exxon Mobil Corporation), Hudson's Bay Oil and Gas Company Limited, Alberta Energy Co. Ltd. (Ovintiv Canada ULC), PanCanadian Petroleum Ltd. (Ovintiv Canada ULC), Petro-Canada Exploration Incorporated, Petrofina Canada Incorporated, Her Majesty The Queen In Right of Canada As Represented By The Minister of Industry (The Republic of Canada)
• Inventors: Smith, Russell G., Schramm, Laurier L.
• Primary Examiner(s): Gantz, Delbert E.
• Assistant Examiner(s): Pal, A.
• Application Number:
  US06/561,118
• Time in Patent Office: 294 Days
• Field of Search: 585/8 R, 585/8 LE, 585/11 R, 585/11 LE
• US Class Current: 208/391
• CPC Class Codes: C10G 1/008 Controlling or regulating of liquefaction processes
• CPC Class Codes: C10G 1/047 Hot water or cold water extraction processes

Abstract

Two or more tar sand feeds are blended in specified proportions in combination with a specified dosage of NaOH to provide a slurry, having a free surfactant content dissolved in the aqueous phase of the slurry, which yields the maximum possible primary froth production from the hot water extraction process.

Claims

1. A process for extracting bitumen from tar sand of varying nature using the hot water process in an extraction circuit, wherein the tar sand is conditioned, by slurring it with hot water and alkaline process aid with agitation, is diluted with water, and is then retained in a quiescent condition to produce primary bitumen froth, the improvement comprising:

selecting a first tar sand feed which, when slurried, is a consumer of free surfactants and a second tar sand feed which, when slurried, is a producer of free surfactants;

and blending said first and second tar sand feeds and process aid in the conditioning step in amounts selected to yield substantially the optimum free surfactant concentration, in the aqueous phase of the process slurry for the circuit, required to yield maximum primary froth recovery.

2. A process for extracting bitumen from tar sand of varying nature using the hot water process in an extraction circuit, wherein the tar sand is conditioned, by slurrying it with hot water and alkaline process aid with agitation, is diluted with water, and is then retained in a quiescent condition to produce primary bitumen froth, the improvement comprising:

determining, for the circuit involved, a measure of the optimum concentration of free surfactant in the aqueous phase of the process slurry, which substantially corresponds with maximum primary bitumen froth recovery from that circuit;

selecting a first tar sand feed which, when slurried, is a consumer of free surfactants and a second tar sand feed which, when slurried, is a producer of free surfactants;

and blending said first and second tar sand feeds and process aid in the conditioning step in amounts selected to yield substantially the optimum free surfactant concentration, in the aqueous phase of the process slurry for the circuit, required to yield maximum primary froth recovery.

3. In the process of extracting bitumen from tar sand of varying nature using the hot water process in an extraction circuit, wherein the tar sand is slurried in a conditioning drum with hot water and alkaline process aid, agitated, and then retained in a quiescent condition to produce primary bitumen froth, the improvement comprising:

(a) determining, for the circuit involved, a measure of the optimum concentration of free surfactant in the aqueous phase of the process slurry, which substantially corresponds with maximum primary bitumen froth recovery from that circuit;

(b) determining, for each of a plurality of tar sand feeds which are proposed for use to make a blended feedstock, the substantially linear relationship which exists between a measure of the concentrations of free surfactant, present in the aqueous phase of its process slurries, and the amounts of process aid added, when a plurality of hot water process extractions are practised on each tar sand feed at different levels of process aid addition, all other conditions being maintained substantially constant;

(c) selecting first and second tar sand feeds, from the group tested, such that, if the test data from steps (a) and (b) were plotted on a graph and cross-hatched in accordance with the appropriate figure selected from FIGS. 3 and 4, the first feed would have a surfactant production line whose intercept is above the zero surfactant concentration line and would have values above the optimum surfactant concentration line at a process aid addition value of less than 0.2 wt. %, the second feed would have a surfactant production line whose intercept is below the zero surfactant concentration line and would cross the zero surfactant concentration line at a process aid addition value less than 0.2 wt. % and greater than the process aid value corresponding with either the first feed intercept or the point where the first feed surfactant production line crosses the optimum surfactant concentration line, whichever is greater;

(d) selecting the process aid addition from the range of values between the vertical boundaries of the cross-hatched area;

(e) determining the proportions of first and second tar sand feeds to make a blended feedstock so that they satisfy the following equations;

space="preserve" listing-type="equation">C.sub.o =X.sub.1 (C.sub.s,1 +R.sub.1 P)+X.sub.2 (C.sub.s,2 +R.sub.2 P)

space="preserve" listing-type="equation">1=X.sub.1 +X.sub.2

where;

C_o is the value determined in Step (a)

C_s,1 and C₂,s are the intercepts for the selected first and second feeds

R₁ and R₂ are the slopes of the surfactant production lines for said first and second feeds

P is the process aid addition selected

X₁ and X₂ are the proportions of first and second feeds used to make the blend;

(f) and supplying to the extraction process said first and second tar sand feeds and process aid in accordance with the values for X₁, X₂ and P.