Hierarchical Membrane For Cleaning Up Oil Spills

rtoz (2530056) writes Whenever there is a major spill of oil into water, the two tend to mix into a suspension of tiny droplets, called an "emulsion." It is extremely hard to separate them, and they can cause severe damage to ecosystems. Now, MIT researchers have discovered a new, inexpensive way of getting the two fluids apart again. This new approach uses membranes with hierarchical pore structures. The membranes combine a very thin layer of nanopores with a thicker layer of micropores to limit the passage of unwanted material while providing strength sufficient to withstand high pressure and throughput.

Comments

Solved problem

[snsh]

Easier to follow Exxon's example and dump tons of dispersant into your oil spill, and watch the globs disappear from plain sight.

Re:Solved problem

[pepty]

You know, I don't think I've ever heard of a mix of cash, lawyers, and lobbyists being referred to as "dispersant" before.

Re:Solved problem

[frinkster]

Easier to follow Exxon's example and dump tons of dispersant into your oil spill, and watch the globs disappear from plain sight.

How this got moderated as Interesting I have no idea - I found it to be quite funny.

But the truth is that that industrial corporations are very sensitive to economics. Crude oil is very valuable and dispersant is very expensive. Any product that allows them to recover the oil economically will be used extensively.

The environmental movement really advanced when people started explaining to corporations that pollution was nothing more than raw inputs that they paid for and are now throwing away. A lot of industrial companies have entire divisions dedicated to selling products produced with what used to be stuff they threw out or paid someone to dispose of.

Re:Solved problem

[i kan reed]

BP got in big trouble for an internal memo that discussed the idea of reclaiming the oil. It was a "how dare they think of protecting their assets after doing this" outrage.

I don't have a strong opinion about that memo or the outrage(even though I'm quite concerned with environmental matters on principle). Just that that happened.

Re:Solved problem

[Immerman]

Perhaps. Economically is the key word though, and that filter is going to have to be phenomenally cheap and effective to make it worth it for recovering oil from seawater. How many barrels of oil at $100 per barrel do you suppose $100 worth of filter can filter out? And then you have the fact that the filtered oil is going to be thoroughly contaminated with salts, plankton, diatoms, and everything else found in seawater that's either oil soluble or bigger than an oil molecule, which could potentially increase refining costs considerably. Plus the costs of operating all the ships and pumping equipment necessary to chase an oil slick around the ocean and filter all that seawater in the first place, which is probably going to dwarf the cost of filters.

This could be a great thing for spill cleanup, It might even help to substantially defray the costs of performing it. But I suspect oil companies will still have to be legally forced to clean up after themselves - after all, they generally don't own the oil until after they've pumped it, and pumping more oil is going to be far more profitable than filtering a spill.

Is this better for pour-over or French Press?

[pepty]

Solomon performed experiments showing the effectiveness of the membranes in separating nanoemulsions while maintaining integrity at high pressure. The team used various techniques — including differential scanning calorimetry, dynamic light scattering, and microscopy — to test the separation efficiency, showing more than 99.9 percent separation. Microscopy images show the membrane in operation, with dye added to the water to make the droplets more obvious. Within seconds, an oil-water mixture that is heavily clouded becomes perfectly clear, as the water passes through the membrane, leaving pure oil behind. As shown in the microscope images, Solomon says, “We’re not only getting rid of the droplets you can see, but also smaller ones,” which contribute to the cloudy appearance.

How much oil (weight/weight) can a piece of membrane hold on to? Can the oil be stripped off of the membrane so that the membrane can be reused? If the answers are "less than 1:1" and "no", this might still be useful as a final purification stage after most of the oil has been removed or for situations where you are trying to clear smaller amounts of more toxic materials.

Re:Already solved?

[tomhath]

Here's a better discussion of skimmers. They certainly have their place and the Elastec design is very efficient.

Skimmers work on a film of oil floating on the surface, not so much for oil that has already gone into suspension under the water. This filter seems to fit the latter scenario better