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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)