Analysis of Algal Polysaccharides as Drag Reducing Agents

Yang He

Chemical Engineering Department

Overview

• Drag force and drag reducing agents(DRA)

• Algal polysaccharides and industrial gums (galactomannans)

• Results

Drag Reducing Agents(DRA):Long chain polymer chemicals that when injectedinto a pipeline where the fluid is turbulent modifies the flow regime by reducingthe frictional pressure drop along the pipeline length

What DRA do?

� Can either provide an increase in flow resulting in a much higher throughput or maintain the same flow rate but with a substantial decrease in energy to save energy cost

� Do not coat the pipeline wall, modify the fluid viscosity or have any chemical reaction with the oil

� Inhibiting turbulent bursts near the pipe wall, increase laminar sub layer

Drag formation and reduction

Drag reducing agents used in this study

Galactomannan seriesRed microalgae Porphyridium sp.

galactose

mannose

Red microalgae Porphyridium sp. polysaccharides procedure

Grow under light source for weeks in

a shaker

• Red microalgae will be harvest and polysaccharides will be formed in the media.

Dialysis with distilled

water for 24

• Wash the media out water for 24

hrs

out

Precipitate the polysaccharides

out • Use 3 volumes

of ethanol

40 L Tank

½ in D, 8 ft L Pipe

¾ hp Pump

Drag in a pipe system calculationDarcy-Weisbach equation

g

phL ρ

∆=

µρDv=Re

2

2

v

g

L

Dhf L

=P1,2 - pressure measured at points 1 and 2

h - head loss

Generally definition of percentage drag reduction

2vLhf L

=1,2

hL - head loss

g - acceleration due to gravity

ρ - density of the fluid

f - friction factor

D - pipe diameter

L - pipe length

w- with additive

w/o- without additive

v - fluid velocity

Drag reduction for galactomannans

15%

20%

25%

30%

% D

R

Locust Bean Gum

Locust Bean Gum

galactose

mannose

1:4

*used by permission of Dr. Azadeh M. Pourmir

0%

5%

10%

0 50 100 150 200

Concentration (ppm)

Drag reduction for galactomannans

1:3 15%

20%

25%

30%

% D

RLocust Bean Gum

Tara Gum

galactose

mannose

1:4

*used by permission of Dr. Azadeh M. Pourmir

0%

5%

10%

0 50 100 150 200

Concentration (ppm)

Drag reduction for galactomannans

1:2

1:3 15%

20%

25%

30%

% D

R

Guar Gum

Locust Bean Gum

Tara Gum

galactose

mannose

1:4

*used by permission of Dr. Azadeh M. Pourmir

0%

5%

10%

0 50 100 150 200

Concentration (ppm)

Drag reduction for galactomannans

1:1

1:2

1:3 15%

20%

25%

30%

% D

R

Guar Gum

Locust Bean Gum

Tara Gum

Fenugreek Gum

galactose

mannose

1:4

*used by permission of Dr. Azadeh M. Pourmir

0%

5%

10%

0 50 100 150 200

Concentration (ppm)

Drag reduction effectiveness with time

15.00%

20.00%

25.00%

30.00%

Tara

Guar

% D

R

1:1 ratio

1:2 ratio

1:3 ratio

0.00%

5.00%

10.00%

0 50 100 150 200 250 300 350

Guar

Locust bean

Fenugreek

Time (min)

1:4 ratio

Effect of Polysaccharide Concentration for Red microalgae Porphyridium sp.

15%

20%

25%

30%

% D

R

Red Algae

0%

5%

10%

15%

0 20 40 60 80 100

% D

R

Concentration (ppm)

Comparison of Drag Reduction Effectiveness

15

20

25

30

%D

R

0

5

10

15

Locust Bean Tara Guar Fenugreek Porphyridium sp.

%D

R

� Drag Reduction ↑ with [polysaccharides] up to 26% at 200 ppm

� Drag Reduction ∝ ratio of galactose to mannose

Conclusion

∝

� Red microalgae Prophyridium sp. has the potential to be used as a DRA

Drag reduction ability up to 25% at 100 ppm

Thanks!

0

5

10

15

20

25

30

Locust Bean Tara Guar Fenugreek Porphyridium

sp.

%D

R

30.00%Tara

0.00%

5.00%

10.00%

15.00%

20.00%

25.00%

30.00%

0 100 200 300 400

Tara

Guar

Locust bean

Fenugreek

% D

R

Time (min)