Membranes, Produced Water Membrane processes, have for a long time been the most preferred water treating techniques that help in salt removal from produced water. In these produced water management processes, salt has always been the major element that guides operators on how they should manage produced water onshore. Injecting produced water for recovery and/or disposal underground, the salt amount will not raise a major safety problem. However, when we intend to recycle and later discharge to onshore surface body water, it is important that we ensure the salt levels are low in order to avoid creation of salt related problems. The processes have been designed in such a way that, while using the membranes, the produced water is purified by removing salt, metals and constituting inorganic chemicals. Among the membrane processes is filtration. This method is done by letting liquids pass through membranes that have small pore sizes. The membrane therefore, acts selectively-only allowing particles smaller than the pores to pass through, while the suspended and dissolved particles large than size of membrane pores get blocked. After tests were carried out, it was found out that the filtration membranes, produced water at different levels depending with the various pore size ranges used. Therefore, various pore size ranges of filtration membranes have come to existence. They include: reverse osmosis, nano-filtration, ultra-filtration and micro-filtration. The energy to push the particle through the pore increases whenever the size of the pores of the membrane decreases. Also as size of the pore decreases, the probability of fouling the membrane increases. With this kind of oscillations in behavior of particles and pore size, membrane filtration is usually done in stages. The first treatment procedure serves to remove larger constituents blocking them from reaching to the membrane depending with the material in the waste-water effluent. Microfiltration and/or ultrafiltration methods can be used in the first treatment module when the reverse osmosis has to be performed in the final process, removing salt and metals. Different chemicals are added to the water treatment technology system for cleaning, antifouling and other pretreatment stage processes. The other membrane process for removing salt from produced water is Electrodialysis. This membrane process separates ions in the solutions. Electric current is then released to the cell, causing the cations to migrate to one point and the anions to another. Here the alternating cells of most concentrated constituents get to be in the membrane spaces as migrating ions try to pass the selective permeable membrane. With the process being administered at a low pressure, the Electrodialysis process consumes less energy than the reverse osmosis process. Though it is a method which has not been tried under full scale operations, another membrane process in use and has been identified for future use is the forward osmosis process. A process which does not require energy from external pressure, forward osmosis is unlike the reverse
osmosis where energy is required for particles to pass through membranes with small pores. In forward osmosis, water diffuses from a stream with low osmotic pressure to a hypertonic solution which has a higher osmotic pressure. New methods are coming up, and are currently being tested to check for their functionality, effectiveness and affordability as they are used in desalinating water. One of them is membrane distillation, which is a process facilitating the movement of particles through a hydrophobic, micropius membrane with the aid of low heat energy. http://www.ociolarium.com/membranes-produced-water/ If you want to see more related items visit http://www.ociolarium.com/
Published on Aug 1, 2013
Published on Aug 1, 2013
Membrane processes, have for a long time been the most preferred water treating techniques that help in salt removal from produced water. In...