Chapter 5
measured by pH test paper. Sample 2 was prepared with 1.0x10'4 M silicate. The
initial pH of the brine was 8.5. The equilibrium pH of the brine was between 8.0
and 8.5. Other combinations of alkali and pH (samples 3-6) were tried as shown
in Table 5.1.
Table 5.1 Emulsion samples with different alkali at different pH
|
Sample |
Na2SiO3 |
NaOH |
*lnitial pH |
“Equilibrium pH |
|
1 |
I |
/ |
8.3 |
8.0 |
|
2 |
1.0x10^4M |
/ |
8.5 |
8.0-8.5 |
|
3 |
/ |
2.0x10’4 M |
8.5 |
8.0-8.5 |
|
4 |
2.0x10'4 M |
I |
8.8 |
8.5 |
|
5 |
I |
4.0x10'4 M |
8.8 |
8.5 |
|
6 |
1.0x1 O’4 M |
2.0x10'4 M |
8.8 |
8.5 |
*The initial pH of brine was measured with a pH meter without contacting with
diluted bitumen.
** The equilibrium pH of brine was measured with pH test paper when the brine
reached equilibrium with diluted bitumen.
5.3.2. Results and discussions
Figure 5.1 shows 24 hours emulsion samples prepared with synthetic brine
and diluted bitumen with dilution ratio 0.7 at 50 0C1 adding 200 ppm demulsifiers
PRi - PR6 and 1.0x1 O’4 M Na2SiO3. Based on the results of bottle test, emulsion
adding PR5 has the best separation and is chosen as the optimal demulsifier.
Figure 5.2 shows photographs of the six emulsion samples with 200 ppm
150