Arriving at the offices of Doosan Babcock, Renfrew, in an electric vehicle, Charles (pictured above, in 2017) was shown the carbon-capture machine CycloneCC, which its inventors at Carbon Clean describe as the world’s smallest device of its type.

Iain Tobin, Carbon Clean’s chief corporate officer, said of the royal visitor: “He was very impressed. He’s genuinely interested in what we’re trying to achieve, which is to bring cost-effective carbon capture technology to hard-to-abate industrial sectors.”

Charles, who is also the Baron of Renfrew, asked questions of staff including Aniruddha Sharma, Carbon Clean’s co-founder and chief executive, and James Hall, the head of research at the company, who demonstrated the vast difference in size between the old carbon capture technology and the new CycloneCC.

Carbon was previously captured using a 15m device, which saw the pollutant mixed with a chemical to extract the carbon from the other gases.

Carbon Clean has created a much smaller device: working like a washing machine, it uses a spinning mesh and a solvent to separate the gas, which not only makes it much smaller, but means it can also be more easily installed on site.

Sharma said that the development of the product, which is 10 times smaller than previous generations, would open up more space for decarbonisation. Tobin described it as a “game changer” for the industry.

Sharma added: “The whole world is here and people are talking about phasing out coal. If cement was a country, it would be the third largest emitter of CO2.

“Here is an example just outside the COP where people can actually come and see how the future’s going to look – you can compress the size of all this equipment and scale it out.”

Charles signed the visitors’ book at the facility, which also revealed that he was not the first royal to tour the site. In June 2010, the Princess Royal opened the emissions reduction test facility at Doosan Babcock.

Meanwhile, Charles used his continued presence in Glasgow to draw the media’s attention once more to the young protestors who have been gathered outside the conference venues since the first day.

On Thursday, The Prince of Wales was invited to join Greta Thunberg and thousands of activists on a climate change march through Glasgow, but he admitted that his taking part would be “difficult”. Charles sympathised with the “frustration” of the younger generation in a speech to COP26 negotiators, in which he told the assembled audience that the “weight of history” is resting on their shoulders.

The heir to the throne met more than a hundred heads of delegations, ministers and officials to urge on their efforts and he sympathised with their plight, saying that the talks had probably cost them time to eat and sleep.

Appearing at Glasgow’s Kelvingrove Art Gallery, Charles stressed how young people were seeking action from leaders to tackle the environmental issues facing the planet.

Speaking last night (Thursday November 4), the Prince said: “There’s a lot of anger and a lot of frustration. There’s a big march tomorrow [Friday], which some people have said I should join – that’s more difficult – but the point is, please don’t forget these people out there. Don’t forget that it’s their future.”

Thunberg had been urging people from all walks of life to join the climate strike protest on Friday – part of her ‘Fridays for Future’ marches – but it is understood that a COP26 youth group also asked the Prince to join them in person.

Charles told the group at the gallery, which included officials from 70 countries and COP26 President Alok Sharma, as well as the UK’s lead climate negotiator Archie Young: “All I particularly wanted to say was that you know – and I don’t need to tell you I hope – that there are so many people out there and around the world, putting so much expectation on your shoulders. And in many ways, the whole weight of history rests on you this time around.”

The Prince also used the Kelvingrove reception to mark his Sustainable Markets Initiative launching the ‘Terra Carta Seal’, with 45 companies receiving the recognition for making significant efforts to adopt sustainable markets.

Speaking about the seal – created by Sir Jony Ive, the ex-Apple chief designer credited with styling Apple’s iPhone, iPod and iPad – Charles told the recipients: “The Terra Carta Seal acknowledges that each industry faces unique challenges in its transition to a sustainable future and they are all at different stages of their journey.

“Here, all industries and all companies must be supported as they take steps in a more positive direction. At the same time, an accelerated pace is required if we are to achieve a 1.5-degree target, restore biodiversity and benefit the lives and livelihoods of current and future generations.”

On Wednesday evening, the Prince of Wales had met film star and environmental campaginer Leonardo DiCaprio as they both viewed Stella McCartney’s sustainable fashion collection. McCartney said that DiCaprio appeared “gobsmacked” that more designers were not “joining forces” with her push for sustainability and ditching leather in favour of more eco-friendly materials.

DiCaprio chatted privately with Charles after they were separately given a guided tour by the designer of her innovative sustainable garments and accessories dubbed the ‘Future of Fashion’.

McCartney’s eco collection included luxury handbags made from vegan, lab-grown mushroom leather and futuristic vegan football boots which the designer created in collaboration with Manchester United star Paul Pogba and Adidas.

McCartney, the daughter of music legend and ex-Beatle Sir Paul McCartney, said she felt that Charles found her exhibition “enlightening and inspiring”.

She added: “I want to highlight my industry and call it out: we’re one of the most harmful industries in the world to the environment and what I’m doing here is trying to provide sustainable solutions and technologies and a better way of doing things.”