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AM components in separation and purification

Additive manufacturing of turbulence promotors and membrane structures is a new approach to fabricating complex structures.
Hello! I will continue now related to  the topic of additive manufacturing   in separation and purification technologies. First, we are going to speak about turbulence   promoters. So, turbulence can be used to reduce  contamination of membranes. It causes also failing   of the membranes, it’s one of the biggest issues  when we are using membrane operations in water   purification. Membranes are getting dirty very  easily and they need to be cleaned very often.   If we put these turbulent promoters inside the  membrane stacks, we create the turbulence in   the flow, which means that the failing  can be prevented, and with 3D printing   we can produce all of these kind of structures  to make optimal turbulence promoters. Here are  
those conditions that have been used for  producing these using polyester elastomer   and fuse deposition modeling (FDM) pro  simple way to produce 3D printed structures.   These elliptic 3D printed promoters in this case   they have found to be the most suitable to  prevent the contamination of the membranes. 
Also membranes can be produced by 3D  printing. With this 3D printing we can   produce 3D structures which with traditional  fabrication we can produce only 2D structures.  
More complicated structures can be produced,  and it enhances the membrane processes. We can   optimize the performance of the membranes and make  them more efficient for the applications which are   usually water purification. Here is one example  where combo side porous material has been used   to 3D print the membrane and this support  of the membrane is then produced by PLA. 
Then, one last thing that can be used in the case  of additive manufacturing of membrane structures  
is spacers. So these spacers are parts  that are put between the membranes   that separate the membranes because there  are usually many layers of the membranes   where this liquid is going through and the  spacers are needed there to separate the membranes   and increase the performance. For example,  we have modified filament spacers,   helical spacers, multi-layered spacers  and moulded membrane in this figure here.  
And finally, if we show the whole membrane module,  
there is the picture which shows that which of  the parts are more difficult to produce with   AM technologies. Here, the green one  - these are easy parts of the stack   of the membrane or the membrane module. A feed  spacer, here, is moderately difficult to produce,   but membrane and spacers are the most difficult  ones. But, actually, there is at least one   producer in China who is producing really  applicable membranes by 3D printing.  
So let’s see how that goes on and  if it comes more popular or not.  Then i will show you something about additive  manufactured absorbents or scavengers.   Adsorption means that we are removing  molecules of components from the water   by attaching them on the surface. So here is  gas or liquid and here is the solid surface, and  
this is limited by active sites on the surface:  how much there are, what is the surface area,   what is the diffusion inside the  system and kinetics of the process.   And additive manufacturing offers possibility to  optimize the shape, size, and flow properties,   decreasing the pressure drop, enhancing the  interactions. Here you can see one of the   examples of additive manufactured filtration  system, and this is nylon based adsorbent   you can put many of these in the same system  and put water through this system here,   and then metals are attached to this material and  actually one of the companies has been recently   started with this technology  and they are really producing   this kind of adsorbents or scavengers for  different recovery and purification applications. 
Then this kind of structures are more studied,  produced by intiate writing so we make the ink or   slurry that is used. And in this case activated  carbon has been added in the slurry to  
make it more efficient to remove for  example organic pollutants from the water.  
An activated carbon is absorbing different kind of  contaminants and here is one example of organics   removal. These kind of structures are quite often  studied and tested for gas operations as well. 
Then here’s the example of one project that is  going on in LUT at the moment. We are producing   ionic choice materials that are selective for  this these metals presented here. These elements,   they are found in sea water and especially  sea water brines where these are going to be   separated we are using different ionic chains  materials mix, that mix them with the PA,   so nylon, here, mix them there then these  powders are used in the SLA printer,  
and then kind of here is the  most simple structure. Like   not looks, not looking like a very more  geometrically challenging structure, but initially   we can produce this kind of coins/filters and  then separate these metals from the liquid phase.  Then photocatalysis is also one important  purification technology. This example shows how   this 3D printed photo catalyst is included in the  powder which contains water, and then sunlight   activates the photocatalyst and make all the  bacterial and all the harmful contaminants to   degrade and after these reactions we can  just take the water out and use it.
And   we don’t need to filter anything  because this solid photocatalyst is   inside here and it is not and it is stable  enough that it’s not leaking into the water. 
And this was the second part of my  lectures and then I have a last one   lecture that is related to the additive  manufacturing in electrochemical methods.

This second lecture relates to the topic of additive manufacturing in separation and purification technologies.

Our case examples are turbulence promoters and membranes. 3D printed promoters have been found to be the most suitable in preventing contamination of the membranes. Also membranes can be produced by additive manufacturing. With AM we can produce 3D structures whereas with traditional fabrication we can only produce membranes with 2D structures.

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