Slurry Asphaltenes

1 In a 500 ml Erlenmeyer weight about 8 or 9 grams of sample – record the weight.

2 Add about 200 ml of n-heptane and reflux for 60 minutes – turn heat off – cool.

3 Close flask with a stopper and store in dark place for 90 minutes.

4 Fold a filter paper and retain with a paper clip and place in glass funnel – use Whatman 41 Ashless circles 110 mm diameter.

5 Without agitation, decant liquid into filter paper – then – transfer as much as possible of the solids into the filter paper – rinse the flask several times with n-heptane and pour the rinsings through the filter.

6 Set the flask aside – it will be used again – do not clean it.

7 Insert the filter paper in the adapter between the condenser and the flask.

8 Add 100 ml of n-heptane to the new flask – set up the reflux and reflux for at least 60 minutes – let cool down.

9 To the original Erlenmeyer flask – add 60 ml of toluene – reflux for 60 minutes at least or until the filter paper is clear and no more dark sample is visible.

10 Weight a clean and dry evaporating dish (vycor dish) – transfer the toluene/asphaltene sample to it and evaporate the sample over a boiling water bath to dryness.

11 Dry the vycor dish in the oven at 120°C for 30 minutes – cool in dessicator for 30 minutes – reweight the vycor dish – this is the residue.

12 Report as % asphaltene = (residue/sample weight) * 100

13 Clean all glassware with toluene and acetone.

14 To clean the vycor dish – wash with toluene – dry – bake in oven at 800°C for 20 minutes.

PPE Use

Standard (SSP-0011) Y

Full Face Shield / Goggles

Hood

Clothing—Chemical Protection

Gloves—Chemical

Personal Fall Protection

Respirator / Filter Mask

Supplied Air

Job Hazards Yes Job Hazards Yes

Access and Egress Moving Parts

Activities of Others Noise

Adverse Weather Rail Movement

Chemical Exposure Sharp Edges

Electricity Slips, Trips, and Falls

Fatigue Static Electricity

Fire and Explosion Trip Injuries

Ground Contamination Trapped Pressure

Manual Handling Working at Height

Other:

References / Documents

N/A

Area Unit Operating Procedure # Certified by Revision # Date Page

3 Lab OPS-LB-NM-032 0 6/28/11 1 of 3

Slurry Asphaltenes

Environmental

N/A

Quality Assurance

N/A

Special Instructions

Any problems, notify Shift Supervisor or Duane Chaisson.

W A R N I N G

C A U T I O N

q Procedure Completed

Date:

Prepared By:

Approved By:

Area Unit Operating Procedure # Certified by Revision # Date Page

3 Lab OPS-LB-NM-032 0 6/28/11 2 of 3

Slurry Asphaltenes (continued)

Slurry Asphaltenes (continued)

15 All glassware – once dry – can be reused.All vycor dishes have to be baked before re-using.

WARNING: Beware of solvents in the area. Turn on water for reflux. Unplug hot plate when finished.

q Procedure Completed

Date:

Prepared By:

Approved By:

Determination of Asphaltenes in Crude Petroleum & Petroleum Products

1Estimate the asphaltene content of the sample, or residue obtained from the procedure in annex A, and weigh the quantity, to the nearest 1 mg for masses above 1 g, and to the nearest 0.1 mg for masses of 1 g and below indicated in table 1 into a flask of appropriate capacity.

2 Add heptane to the sample in the flask at a ratio of 30 ml to each 1 g of sample if the expected asphaltene content is below 25%. For samples with an expected asphaltene content of above 25%, a minimum heptane volume of 25 ml shall be used.

3 Boil the mixture under reflux for 60 min ± 5 min. Remove the flask and contents at the end of this period, cool, close with a stopper, and store in a dark cupboard for 90 min to 150 min calculated from the time of removal from reflux.

4Place the filter paper in the filter funnel using forceps. Thereafter handle the filter paper only with forceps. Without agitation, decant the liquid into the filter paper, and then transfer the residue in the flask as completely as possible, using successive quantities of hot heptane, using a stirring rod as necessary. Give the flask a final rinse with hot heptane and pour the rinsings through the filter. Set the flask aside for use, without washing.

5Remove the filter paper and contents from the funnel and place it in the reflux extractor. Using a flask different from that used initially, reflux with heptane at a rate of 2 drops to 4 drops from the end of the condenser for an extraction period of not less than 60 min, or until a few drops of heptane from the bottom of the extractor leave no residue on evaporation on a glass slide.

6 Replace the flask by the one used initially, and to which has been added 30 ml to 60 ml of toluene, and continue refluxing until all the asphaltenes have been dissolved from the paper.

7Transfer the contents of the flask to a clean and dry evaporating dish weighed to the nearest 0.2 mg by tare against a similar dish. Wash out the flask with successive small quantities of toluene to a total not exceeding 30 ml. Remove the toluene by evaporation on a boiling water bath.

CAUTION: Perform the evaporation in a fume cupboard.

8Dry the dish and contents in the oven for 30 min. Cool in the cooling vessel for 30 min to 60 min and reweigh by tare against the dish used previously for this purpose, and which has been subjected to the same heating and cooling procedure as was the dish containing asphaltenes.

NOTE: Asphaltenes are very susceptible to oxidation, and it is important that the procedure specified in the final drying stage is adhered to strictly as regards to temperature and time.

Calculation1. Calculate the asphaltene content, A, in % (m/m), on petroleum products using the equation A = 100(M/G) where M is

the mass, in grams, of asphaltenes; G is the mass, in grams, of the test portion.2. Calculate the asphaltene content, C, in % (m/m), of crude oils prepared in the manner described in annex A using the

equation C = 100(MR/GD) where M is the mass, in grams, of asphaltenes; R is the mass, in grams, of the residue from distillation; G is the mass, in grams, of the residue aliquot; D is the mass, in grams, of crude oil sample distilled.

Area Unit Operating Procedure # Certified by Revision # Date Page

3 Lab OPS-LB-NM-032 0 6/28/11 3 of 3

Slurry Asphaltenes (continued)

Preparation of Crude Petroleum Residue by Distillation

1 Determine the density of the crude oil at 15°C by ISO 3675 or ISO 12185.

2Weigh the distillation flask to the nearest 0.1 g and charge it with the mass of 100 ml of sample at 15°C to within 0.1 g, ensuring that no oil flows down the _________________________________. Place the thermometer so that the bottom of the bulb is 2.0 mm ± 0.5 mm from the bottom of the flask.

NOTE: The position of the thermometer in its holder may be premarked before addition of the sample to the flask.

3Swab out the condenser tube and assemble the apparatus, with the vapor tube of the flask extending into the condenser tube a distance of between 25 mm and 50 mm. Make the connection between flask and condenser tube tight by means of a stopper or bung through which the vapor tube passes.

4Place a clean, dry receiver at the outlet of the condenser such that the condenser tube or adaptor extends into it at least 25 mm, but not below the 100 ml mark. Immerse the receiver up to the 100 ml mark in the transparent bath. Cover the top of the receiver closely during the distillation with a piece of paper weighted to restrict volatile losses, and also to overcome the buoyancy of the receiver in the water bath. Circulate ice-cold (below 4°C) water through the condenser.

5Apply heat to the flask and distil the crude oil at a rate not exceeding 2.5 ml/min until it ceases to foam, after which keep the rate of distillation constant at 2.0 ml/min to 2.5 ml/min (approximately 1 drop). Continue the distillation without interruption to 260°C. Remove the heat and allow the condenser to drain into the receiver.

6 Use this residue to carry out the procedure for the determination of asphaltene content.

q Procedure Completed

Date:

Prepared By:

Approved By: