Mixing method and system for increased coalescence rates in a desalter
View Patent ↗The present invention relates to crude oil-water separation processes, specifically desalting in a petroleum refinery. More particularly, the present invention relates to a method and system for increase coalescence rates of water drops in a desalter.
1. A method for reducing a salt content of crude oil comprising:
a. dividing the crude oil stream into a first stream and a second stream;
b. mixing the first stream with a wash water stream resulting in a first oil/water stream;
c. mixing the second stream with a wash water stream resulting in a second oil/water stream;
d. combining the first oil/water stream and the second oil/water stream resulting in a mixed oil/water stream;
e. routing the mixed oil/water stream to a separator vessel whereby at least a substantial portion of the salt content is absorbed by water in the mixed oil/water stream;
f. electrostatically treating the mixed oil/water stream in the separator vessel;
g. extracting water from a lower portion of the separator vessel; and
h. extracting treated oil from an upper portion of the separator vessel.
2. The method according to claim 1 , wherein a first mixing valve is used to mix the first stream with the wash water stream.
3. The method according to claim 2 , wherein the first mixing valve has a low pressure drop.
4. The method according to claim 1 , wherein the second mixing valve is used to mix the second stream with the wash water stream.
5. The method according to claim 4 , wherein the second mixing valve has a high pressure drop.
6. A method for reducing a salt content of crude oil comprising:
a. dividing the crude oil stream into a first stream and a second stream;
b. routing the first stream to a first mixing valve, wherein the first stream is mixed with a wash water stream resulting in a first oil/water stream, wherein the first mixing value has a low pressure drop resulting in large drops of water in oil;
c. routing the second stream to a second mixing valve, wherein the second stream is mixed with a wash water stream resulting in a second oil/water stream, wherein the second mixing valve has a high pressure drop resulting in a small drops of water in oil;
d. combining the first oil/water stream and the second oil/water stream resulting in a mixed oil/water stream;
e. routing the mixed oil/water stream to a separator vessel whereby at least a substantial portion of the salt content is absorbed by water in the mixed oil/water stream;
f. electrostatically treating the mixed oil/water stream in the separator vessel;
g. extracting water from a lower portion of the separator vessel; and
h. extracting treated oil from an upper portion of the separator vessel.