5 engineering solutions for a sustainable future

world engineering day

Apparently the 4th of March is now World Engineering Day.

Today is March the 4th and also the first World Engineering Day (WED). The proposal for it was accepted by UNESCO last year, so 2020 is the first year when the so called World Engineering Day for Sustainable development is celebrated, which also coincides with the onset of the Horizon 2020 projects, the largest European research and innovation funding scheme to date.

The official World Engineering Day page tells us that it is “A UNESCO International Day, An Annual Celebration, Every 4th March-to highlight the achievements of engineers and engineering in our modern world and improve public understanding of how engineering and technology is central to modern life and sustainable development.” It also comes with 17 UN Sustainable development goals, such as goal 13: climate action. Sounds great right?

The young, idealistic researcher part of me thinks that it’s high time the issue of climate change really moved from dire science warnings to developing global scale engineering solutions, but the cynical part of me wonders whether the general public will subject us to the same uneducated scrutiny that has been plaguing the scientists every time someone brings up vaccines or climate change (the general attitude towards nuclear power says yes). However, as my blog name tells you in no uncertain terms, I’m a mechanical engineer specialising in Tribology and the engineer part of me says that it doesn’t really matter: we’ll give you solutions and they’ll work even if you don’t believe our explanations of how they work or don’t agree with them.

Here’s me, a real live engineer on the first day of my engineering PhD.

The transition to a low carbon economy and sustainable lifestyle will largely be a technological challenge and by the time the societal majority really gets with the programme we must already have practical and feasible solutions, otherwise we’re doomed. Development of good engineering solutions and innovations is however, not measured in days or even months. It is a marathon, which requires a lot of investment money and plenty of educated nerds. Although there are already thousands of engineers working towards sustainable solutions and alternatives, the area of green engineering is still severely underfunded where it really counts, because most of the money is going towards electric cars rather than towards economically viable solutions for reducing manufacturing carbon emissions or dealing with all those tons of waste.

I choose to believe that this new World Engineering Day signifies another step in the right direction, particularly if it will start coming with special R&D funding options… A girl can dream, right? Either way, it is by no means all doom and gloom, so I’ve decided to share 5 current engineering solutions with a huge potential for a more sustainable future, explained in simple terms and hopefully viable in the long run:

Plastic waste roads

Apparently this one has been around for a couple of years, but I somehow didn’t find out about it until recently. The current trend is to mix up to 5% of recycled plastic waste with bitumen (asphalt), which requires less bitumen, uses up non-recyclable plastic waste (5% adds up a lot if we consider how many roads there are in the world), improves road lifetime and makes it less susceptible to potholes and cracks. It is also cheaper, because plastic waste is abundant and free, so it’s no wonder India has been leading the way with plastic paved roads due to their trash crisis. The UK, Australia, Indonesia and Mexico also have such roads and they will likely build one in the US soon too. Here’s a scientific article and a company page for those of you who want to know a bit more.

In addition, a European joint venture has built the first real plastic road in the Netherlands in 2018. It is really a bicycle lane, but it is fully made of recycled plastics and hollow by design. It’s quite genius really, because plastic roads like that can be prefabricated (shorter construction time), the hollow space can be used for water drainage or cables and the roads are lighter and more durable (supposedly). Obviously the demand is huge, because every country is drowning in plastic waste, the material is dirt cheap and they can sell their proprietary technology for oceans of cash.

While I really admire both ideas and am all for closing the loop, I’m a bit wary of such end-of-the-line solutions, because they can make us feel like we can just keep producing disposable plastic indefinitely, because we have ways of figuring it out. As someone who has spent a couple of years working with polymers (plastics), I also have some concerns about road creep (slow movement and deformation of the material) in hot areas and the general durability of such a road periodically exposed to hot and cold temperature conditions, but the roads have performed admirably so far. Other very real problems include the possible microplastic contamination of the surrounding area, the release of volatile toxic gases during production and possibly also during road use in hot environments, and the fact that not all plastic waste is suitable for road paving.

Water hydraulics

The field of hydraulics is one of the core fields of mechanical engineering, which is basically the reason why we can operate heavy machinery (trucks, cranes etc.). The basic principle of hydraulics is that you can’t squash liquids within a container. If you’re trying to push a liquid through a fat pipe into a narrower one, you’ll need to apply a lot of pressure and it will come out squirting at high speed and vice versa – if you’re pushing a lot of liquid at once from a narrow pipe into a larger one, it will move slowly through but will push ahead with lots of force. If the liquid is air, then we’re talking about pneumatics.

Anyhow, mineral oils are the most commonly used hydraulic fluids, because their flow is the right viscosity and easy to control, they can operate at high pressures, any temperature and also lubricate the mechanical components in the system, which is essential for reducing friction and increasing their lifespan. However, since a hydraulic system is an assembled mess of pipes, pumps, filters and motors, there’s always a bit of oil leaking out somewhere. It’s called acceptable leakage, but it’s essentially contamination of the environment + the oil needs to go somewhere after it’s no longer usable.

The obvious safe solution is to use water instead of oil – water hydraulics. However, water is corrosive to metals, attracts bacteria, freezes and evaporates at the pressures and temperatures required in heavy machinery and is a poor industrial lubricant, because it can’t reduce friction through film formation (an oil film separates contacting surfaces and prevents wear). Some of these disadvantages can be mitigated by adding additives to the water, but essentially water hydraulics presents a unique redesigning challenge for all currently used hydraulic systems.

Materials for all hydraulic components will need to be re-selected and the use of special coatings like DLC shows great promise when used with water, but it’s not just about changing the material. A friend of mine recently defended his PhD where he showed that even details like slightly changing the diameter and location of holes in a hydraulic motor can increase its efficiency when using water. More about the + and – of water hydraulics here.

3D printed artificial coral reefs

This one is more specific than the other ones, but I included it because it’s a great example of how technology can be used to conserve and restore ecosystems. At this point, pretty much everyone knows about 3D printing and it’s enormous potential in just about every field and ocean conservation is no different. Some guys in Australia made and sunk a 3D printed artificial coral reef and while it may sound like a fad, it has been proven that corals are quite picky with their homes. Apparently they prefer porous structures with certain surface topographies, so that’s what they designed for them. 3D printed sandstone blocks have also previously been used for artificial reefs, but they’re heavy and hard to transport, while this solution is lightweight and modular. Here’s a couple more examples of technology use in coral reef restoration.

The very bleached Great Barrier coral reef in Australia.

Green lubricants

Going back to fluids and lubricants: basically anything from your door hinges to parts of your car needs to be lubricated. Most of these lubricants are of course oil-based and their performance is further enhanced by oil additives, neither of which screams environmentally friendly. That’s where the initiative for green lubricants comes in and it’s currently a hot topic in my field, Tribology.

While the push to find an alternative to oils for as many applications as possible is basically an impossible dream (although ionic liquids are relatively promising), there is a class of supposedly green lubricants called EALs. EAL means environmentally acceptable lubricants (note the acceptable, not friendly part), which are assessed mainly on their biodegradability, toxicity and bioaccumulation and based on vegetable oils, synthetic esters etc.. Although they have their uses, they are still quite far behind the regular lubricants in terms of industry use, despite what certain companies would have you believe (here‘s a propaganda article, which is actually quite good at explaining the EALs).

The other part of the deal are lubricant additives. One of the most controversial oil additives in the industry is called ZDDP and replacing it has proven to be a hard challenge. ZDDP is used in cars and manufacturing because of it’s awesome performance in reducing friction and wear, but it contains lead, so whoever finally formulates something with comparable performance for a similarly wide range of materials will be swimming in money.

The ITER project

Naturally, I couldn’t finish this post without delving into energy production. While everybody knows about nuclear power plants, not everyone actually understand how they work and why they’re the best sustainable option we have (which will be the topic of a future blog post at some point), few non-engineers/physicists know about the ITER project.

Nuclear power plants work on the principle of fission, splitting an atom in half, which releases nuclear energy. In contrast, ITER is meant to operate on the principle of fusion, the joining of two light atoms into a heavier one, which also releases a lot of energy, because the new atom doesn’t have the exact same mass as the joining atoms and the mass loss is transformed into energy (that’s how the Sun works). Fusion produces more energy than fission and is entirely carbon or waste free, if we don’t count the building of the fusion device.

ITER is one of the most ambitious energy production projects in the world, located in France and founded by 35 countries (China, USA, Japan, Korea, the entire EU, India and Russia). The project is set to run for 35 years, started in 2005 and will first be switched on in 2025 if everything goes well. The sole aim of ITER is to prove that fusion can be a viable large scale option for producing energy so that we can one day build fusion power plants.

Why does it take so long to build one measly fusion device you might ask? In order to induce fusion, the atoms need to be super hot, because fusion is only possible if the atoms collide at super high speed. At its core, temperature is basically the measurement of how fast the atoms are moving – the faster they are, the hotter it will be. In order to be hot enough, the atoms need to be moving in plasma, an ionised state of matter where electrons separate from their nuclei. Heating up the plasma uses a huge amount of energy and we need to find a way to produce more energy with fusion than we are putting into initiating it.

That’s it folks! If you’ve made it until the end of this post you deserve to be named an honorary engineer, so you can also feel celebrated on this World Engineering Day with me. I hope you liked it and if you have any questions feel free to ask in the comments below, there are no dumb questions, only dumb answers. 🙂

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