cheap chemical to separate oil from water efficiently
cheap chemical to separate oil from water efficiently
(OP)
Dear Friends
I am looking for a cheap chemical which can demulsify oil from water.The oil is petroleum based.
Any suggestion from you will be very helpful.
Thanks.
TC
I am looking for a cheap chemical which can demulsify oil from water.The oil is petroleum based.
Any suggestion from you will be very helpful.
Thanks.
TC





RE: cheap chemical to separate oil from water efficiently
RE: cheap chemical to separate oil from water efficiently
RE: cheap chemical to separate oil from water efficiently
could you please elaborate on your replies and specify something in particular based on your experience. I am also intrested in a cheap demulsifier.
Thanks in advance.
RE: cheap chemical to separate oil from water efficiently
RE: cheap chemical to separate oil from water efficiently
We have used salt NaCl to break emulsions. You can use caustic to break water/ oil emulsions. You can also use a pressure shock. Like passing the emulsion through an orfice plate with a high pressure drop and then into a settling tank. As mentioned earlier sometimes temperature will break the emulsion.
Good Luck
StoneCold
RE: cheap chemical to separate oil from water efficiently
TTFN
RE: cheap chemical to separate oil from water efficiently
If you're looking for the CHEAPEST chemical, though, that would be carbon steel (at least per kg!), in the form of a large settling drum, which would do at least part of the job for you.
Antifoam costs somewhere in the order of 5-10$/kg if I remember correctly, and you obviously need an injection skid.
But once again, it all depends on what emulsion you have. If it is caused by very small particles, a fine filter (say 1 micron) may help a great deal too.
RE: cheap chemical to separate oil from water efficiently
The importance of knowing what type of emulsion tcchandran and khan101 are referring to, can be exemplified by a typical W/O emulsion as it occurs during normal operation of IC engines.
In addition to the primary functions of lubrication, oils must also contend with various combustion products, mainly acidic gases, moisture, metallic catalysts, oxygen, partly oxidized chemicals and carbon particles. For this reason dispersant and detergent additives are formulated with the lube. Unfortunately, these and other additives, such as VI improvers, act as surfactants having a stabilising effect on foams and emulsions that may form under the high shear regime.
Typical demulsifiers for these W/O type of emulsions comprise more than one component, that must be attracted to the interface and have limited solubility in the bulk phase. Their greater affinity to the water-oil interface ensures that the stabilising molecules are displaced.
Another important feature they exhibit is a reduced inter-droplet repulsion, allowing the droplets to aggregate. The final demulsifying stage is typified by a decrease in interfacial tension and surface area. Apart from good filtration to remove the resulting concentrated solid and debris, stubborn emulsions require the application of a chemical at the final film-rupture stage.
It has been said that the skill of formulating a demulsifier is a "black art". In effect, the selection of an effective demulsifier relies on a "trial and error" approach, suplemented by some knowledge of what has worked before.
The rate of water coalescence is taken as a measure of the effectivenes of the product. Almost every class of surfactant has been found to exhibit demulsification properties.
The most commonly used products in motor oil formulations contain anionic surfactants (e.g. alkyl naphthalene sulphonates) and nonionic surfactants such as alkoxylated alkyl phenol resins and block copolymers of ethylene oxide and propylene oxide.
RE: cheap chemical to separate oil from water efficiently
Which is a better demulsifier Sod.Chloride or Caustic Soda?
Normally what doses would you recommend? In my case I am trying to separate oil from the water and not water from the oil.
Your suggestion will be most helpful.
Thank you
TC
RE: cheap chemical to separate oil from water efficiently
Strong emulsions are formed with compounded oils and detergent oils. Separation is next to impossible by gravity separation or filtering. Chemical methods are complicated and expensive.
In practice, reasonable separation could be obtained by using only pure mineral oils, with no animal oil or detergent additives. Then the oil would float on the water surface and could be collected. Sponges, excelsior, or toweling filters would catch the oil. This system was installed on every Liberty Ship of WWII.
The reciprocating steamships of the last century developed methods to do away with oil lubrication of the steam cylinders altogether, just to avoid the problems of oil in feedwater.
Note that purchasing "non-detergent" oil does not usually mean there is no detergent in the oil, it only means that the oil did not meet the specification requirements for a better grade of detergent oil, and is therefore marketed as "non-detergent". I use straight Veterinary Grade mineral oil for applications where I need to collect traces of oil from the water.
RE: cheap chemical to separate oil from water efficiently
RE: cheap chemical to separate oil from water efficiently
What you really need to do is get in the lab and do some experiments based on the information you have gained here.
As other have explained the "best" or cheapest separating agent will depend a lot on the actual process conditions and the oil to be separated. Try some of our ideas and then come back with more questions and more information if you do not like the results.
Goodluck
StoneCold
RE: cheap chemical to separate oil from water efficiently
RE: cheap chemical to separate oil from water efficiently
Save yourself some grief and contact Nalco or GE Betz, to name two of many, and let them do the screening work for you to find the most effective, least expensive demulsifier for your system. As this technology is very mature, it should be a simple matter to satisfy your requirements.
Orenda