NuScale Modular Reactors - My Understanding in 30 Minutes.

NuScale is a company that manufactures self-contained modular nuclear reactors, which are controlled from a single control room. It is a fairly small reactor that operates underground in water filled pool. The benefit of this therefore is that no pumps are needed to circulate the water through the vessel, since the system uses a convection process.

From my understanding the convection process works in the following way:

• water rises to the top of the vessel as reactor is heated up 
• the water is then taken downwards by cool water passing through steam generators as cool water has higher density so its pulled down by gravity to the bottom of the vessel where it is again passed over the core.  
•  as hot water passes over hundreds of tubes in the steam generator, the heat is transferred through the tube walls and the water in the tubes turns to steam.
• The steam then turns the turbines, which are attached to an electrical generator. 
•  The steam loses its energy once it apses the turbines and is cooled back into liquid form
• The water is then pumped back into the steam generator

The benefits of this module are that it is safe as it can shut-down and self-cool without any operator intervention. It is also quite a simple design (I think even I can understand it... somewhat). It is easy to transport due to its size and simplicity.

This reactor vessel seems important in chemical engineering as chemical engineering seems to focus partially on things such as heat transfer and efficiency as well as economy of all processes. This reactor seems to tick off those things. However, the company is from the United States and so its technology has not yet been used in the UK, although they are attempting to make this happen.

Sources used:
[1] http://www.tcetoday.com/latest%20news/2015/october/nuscale-hopes-to-bring-modular-reactors-to-uk.aspx#.VhQbmrRViko
[2] http://www.nuscalepower.com/smr-benefits/secure
 

Coloured PET Recycling - My Understanding in 30 Minutes.

First off, it is a shock to me that until now we have only been able to recycle colourless PET... I actually did not know this! It always seems like everything in the world has been figured out, and everything has been thought of with the 7 billion people on this Earth... But that is not the case! Coloured PET has always been made into lower quality materials or put into incinerators which basically burns the plastic so landfills are not wasted. Yet, from my understanding the company Ioniqa has now been able to scaled up their process of recycling coloured PET, which seems to be a pretty big deal! The company expects their recycled PET to be as good as the PET that is from petroleum sources. 

My understanding is that the process works in the following way:

• The environment for the process has to have atmospheric pressure and temperatures between 150-200 degrees.
• You then add magnetic fluid and Ethylene Glycol (EG) to the coloured PET, which depolymerises the PET and releases colorants into the reaction mixture.
• Magnetic separation is the next step, which removes the colorant with magnetic fluid.
• You are then left with the raw material of PET

… of course this is the simplified version that I have read, I’m sure the actual process is a lot more complex.

Nonetheless, this is a great move towards consideration of the environment and looking into green processes and creation of renewable resource processes. Many companies which use a lot of PET will be most likely be considering this process once it starts to run, hopefully, in 2017. Perhaps we will be able to reach one of the Global Goals, climate change and using sustainable consumption and production , that were set almost a week ago by the United Nations.  

Sources used:
[1] http://www.tcetoday.com/latest%20news/2015/september/engineers-plan-world-first-pet-recycling.aspx#.Vg2aV2RViko 

Fluid Mechanics - My Understanding in 30 Minutes.

Having looked at various University modules for Chemical Engineering, fluid mechanics seems to be common first year module… So I thought I would give it a go and try to understand as much of basics of it as I could. 

Firstly, fluid mechanics is the study of statics and dynamics of fluids and how forces act on them. Static fluid is fluid at rest and dynamic fluid is obviously fluid that is in motion. Fluid mechanics also assumes that every fluid complies with conservation of mass, energy and momentum. We must now define what a fluid actually is. Out of the 3 states of matter, solid, liquid and gas, a fluid fits the description of a liquid and a gas. Originally I found it odd to find out that a gas was considered a fluid, since I’ve always thought of fluid as a liquid only, yet actually gases also make sense… Well its scientifically proven! The way we know to consider both liquid and gas a fluid is through their response to a shear force, which from my understanding is a pair of forces that push something in opposite directions. A solid resists a shear force, whereas liquids and gases do not as they can flow and therefore continuously deform as a result. The different variables needed to define a fluid and its environment are, pressure, velocity, density, viscosity, body force, time and temperature. Fluid mechanics can be solved using computers since it involves complex mathematics, such as Computational Fluid Dynamics, which uses numerical analysis and algorithms to analyse problems of fluid flow. Particle image velocimetry on the other hand, is an experimental method to analyse fluid flow and its problems. Fluid mechanics also links to continuum mechanics, which studies the physics of continuous materials e.g., fluid. Continuum mechanics is based on some approximation and so therefore its solutions are also approximate so there is minor inaccuracy.

Fluid mechanics is of importance to chemical engineers, well all engineers and physicist for that matter, as it can help them solve many problems such as water supply systems, determining flow of petroleum through pipelines and even making devices to mix industrial chemicals… as well as many, many more things!