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  • Writer's pictureSol J

Replacing liquid fossil fuels - it's about more than just energy

While we rush to transition off fossil fuels as an energy source, how many of us spare a thought for how we'll replace them as feed stocks for important chemicals and industrial materials?

Behind the climate change debate is the lurking spectre of fossil fuel depletion and the societal crunch that is occurring as our primary energy reserves become exhausted. But there is another even more pernicious question that few have dared to ask - how will we replace all the plastics, fertilisers and other industrial products that come from fossil fuels?

"What you get free costs too much." - Jean Anouilh

A typical modern sedan is comprised of as much as 50% petroleum based materials by weight. This includes plastics, synthetic fabrics, adhesives, specialised low-wear components, not to mention all the fluids that are involved in the manufacturing process such as casting release agents, solvents and the fluids that are required as consumables during the ongoing lifetime of the car (brake fluid, oils, greases, etc.)

If we look at our overall global fuel supply chain efficiency, the whole of the oil industry operate as a net energy sink: it uses more energy than it extracts from the ground as crude oil. To keep operating it drains energy from other primary sources than oil (see more about this in our other blog post on hydrogen here).

We estimate that the amount of crude oil equivalent used to create all the synthetic materials in a car in 2015 was over 12 times the amount of final products that actually ended up in the car. If we say a typical small family SUV contains about 600kg of plastics, then by the time we’ve jumped through some hoops it works out to be about 10,000 litres of oil equivalent per car. If you're wondering what that looks like, this truck is carrying enough oil to create all the synthetic materials to build just one family sized car (in 2015 terms):

And that's just what actually goes into the car, that's before we've expended any energy refining, reforming, transporting or actually working them into shaped products that can be installed on a production line. Compared with 2015, the situation in 2021 has worsened considerably (it gets harder to estimate as we look closer to the present). The supply chain for the products we take for granted is endangered.

What about things like tyres? Ideally, a car has five of those.

A typical car tyre contains about 30 litres of petrochemicals. So that's 150 litres to re-shoe a car every 2 years or so. When we consider the additional overhead cost in consumed oil of bringing those tyres to market, a car built in 2015 consumed about 1,875 litres in its showroom tyres alone.

The situation is worse for an electric car. A typical compact electric car such as a Tesla Roadster contains a battery that might have another 200-300 kg worth of plastics in it. We won't go into the maths any further, you get the idea. Most of those aren’t recyclable and once used, are lost forever.

Each litre of petrochemical requires more than one barrel of oil to produce and as we have seen earlier, the ongoing supply of those barrels is now endangered. Within the next ten years the petrochemical feed stock industry will be as much in disarray as the transport fuels industry.

Not only is the amount of oil required to build a car going up and up, the faster we try to replace existing cars with more economical or electric cars, the harder we are driving this race to infinity. That race is expected to top out around 2030 or so. So when you run out your last set of tyres that cost you, say, three years' wages, the Tesla will go on a display stand in the man cave, no more tyres for you.

Why do we use petrochemicals to make these materials?

It’s the same reason we use them for fuels – they contain a lot of stored energy in their chemical bonds. If we had to make plastics and synthetic materials from scratch, the amount of energy required (and therefore the cost) would be huge. Instead, we use petrochemicals (i.e. fossil fuels) because with a small amount of energy we can modify these existing molecules fairly cheaply to give us a whole range of useful products without having to create most of the chemical bonds that hold them together.

It’s that old chestnut of energy efficiency – getting back as much as we can whilst putting in as little as we can. That’s why plastics are affordable and preferred for mass manufacture, the raw materials already contain much of the energy in chemical form and therefore don’t require a lot of energy to produce. But the hidden cost in oil and carbon emissions required to bring them to us is immense and rising exponentially.

This is a question that needs to be urgently answered. Although we can categorically state that plastics are not good for the environment, they nonetheless fill a manufacturing requirement and until we can come up with “something else” they will still be needed for some time yet. The same can be said of all petrochemical precursors and they are used in everything that defines our modern world, from packaging to pharmaceuticals, industrial chemicals, solvents, adhesives, paints, building materials, batteries, toothbrushes and almost every single piece of consumer electronics you can imagine. Modern farming is made possible by petrochemical based fertilisers, pesticides, and herbicides. Without them a large proportion of the world’s agriculture would become impossible with mass starvation being the result. We are totally dependent on petrochemical technologies, not just for energy but for industrial inputs as well. Without synthetic materials our present world would disintegrate overnight.

The “something else” is possible now, chemical engineers have developed all sorts of advanced materials, including many substitutes that can be made from organic and natural substrates derived from a range of biomass forms. Many of these substitutes are not financially viable when stacked up against petrochemical based materials – but it all comes down to available energy. The more energy we have, the more options we have and the more advanced materials we can make without relying on petrochemicals. Many of these can be designed to be biodegradable or recyclable with low recovery costs.

The hidden emergency that is coming is that the demand for fuel will always exceed the demand for chemical precursors. We need to commence a transition to more efficient energy supply chains that recycle heat from thermal solar where it can be used in processes to replace the energy in the chemical bonds that provide the basis of our present petrochemical feed stocks. Pivoting the chemical industry will take time and it's not financially viable to migrate it off petrochemicals without a more efficient source of energy. If we are able to engage in this work whilst already commencing the transition off fossil fuels we can have a new non-petroleum plastic industry fully operational before petrol-based plastics become unavailable.

nGeni offers an exciting opportunity through its ability to recycle heat streams at multiple different temperatures with almost no additional energy input, thus replacing several separate energy inputs that usually result in wasted heat in traditional industrial chemical processes. By interfacing a customised nGeni GreenBox into existing and purpose built plant, it will be possible to replace several energy consuming processes, usually powered from the feed stock, with a single solar powered process that allows lower grade inputs to be used whilst still remaining economically viable.

The resultant industrial chemicals will be produced using carbon neutral energy and in conjunction with the direct air carbon dioxide capture module, can utilise environmental carbon as part of the feed stock, closing the carbon loop and fixing carbon into a new range of biofriendly synthetic materials. In this way manufacturing can be used to repair the environment, whilst allowing the transition of both energy and materials feed stock from depleting petrochemical fossil fuels.

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