Koji Muto spent his career inside the hydrogen business, latterly at ExxonMobil, and what he kept running into wasn't a technical problem. It was an arithmetic one.
The world makes more than 95 million tonnes of hydrogen a year. Almost none of it is green. It goes into fertiliser, textiles, plastics and refining, and producing it emits roughly 900 million tonnes of CO2 annually. The clean alternative, splitting water with electricity, works perfectly well and has done so for two centuries. It just costs more, because water is a stubborn molecule and pulling the oxygen off it takes about 50 kWh of electricity for every kilogram of hydrogen you get out.
That gap is what the industry calls the green premium, and it's why most industrial buyers keep signing for the grey stuff. Muto's view was that no amount of policy would close a gap that large. The cost had to come down at the level of the chemistry.
At Carbon13's venture builder, he met Michael Stanton, a Cambridge physics and nanotechnology PhD, and the two of them went at the problem from the other end. Instead of splitting water, split biomass. Wood chips, agricultural residues, the material that's already lying around. A low-temperature electrochemical process pulls the hydrogen ions off lignocellulose using a catalyst that loops continuously and skips the oxygen-production step that makes water electrolysis expensive.
Two things come out. Hydrogen at better than 99% purity, for around 25 kWh per kilogram, half the energy of water electrolysis. And biogenic CO2, the carbon the plant took out of the air in the first place, for about 0.3 MWh per tonne, against the 2 to 3 MWh per tonne that direct air capture demands.
Hydrogen and biogenic CO2 are the two feedstocks you need to make synthetic fuel. Getting both out of one process, from waste, is the company's commercial advantage.
Ki had the problem every deep-tech founding team has. A process that works on a bench isn't a company, and the people who fund companies want to see a company. Muto and Stanton had a chemistry result: no product, no revenue, no customers, and they'd never worked together before.
Carbon13's programme is designed for exactly that gap. It recruits climate-motivated technical and commercial people into a cohort, puts them in front of each other, forms teams around problems, and then invests in the teams that hold together. It's run that process since 2021 and is now on cohort 10, the cohort Fund X will invest in.
The funnel is steep. Around 600 people apply, about 80 get a place, half of them scientists and engineers, half commercial operators. They form teams of two to four, the ideas whittle down to 20 to 25 by the second phase, and 6 to 8 of those take investment. Roughly one in a hundred applicants ends up in a funded company. Ki was one of them.
Ki closed a pre-seed of about £880,000 across September and November 2023, the round Carbon13 took part in. Founders Factory's climate programme, G-Force, came in at the November tranche. Louis Warner, the G-Force partner, described the team at the time as "the best team we could find who are working on a realistic path to cost-competitive green hydrogen".
In July 2024 the company won a £470,000 Innovate UK Smart Grant to take the biomass electrolysis process forward. Koji Muto's comment on the award was that the project "was chosen for both its innovation and scalability". A second and larger Innovate UK award followed.
In November 2025 HICO Investment Group led a £2.25m tranche of seed funding, joined by GiTV and Desai Ventures.
Then, on 2 September 2026, the company announced the round publicly at $5m, alongside non-dilutive match funding from Innovate UK, which sits outside that figure. The company also changed how it describes itself, from Ki Hydrogen to Ki 13, reflecting a shift from selling hydrogen to selling the two feedstocks synthetic fuel needs.
Ki reports hydrogen purity above 99%, more than 95% emissions reduction against the fossil route, and over $15m of annual recurring revenue signed in letters of intent with European e-fuels producers. They have also arranged biomass supply agreements covering five years of scaling.
And the team has grown too. Matthew Howard joined as CTO, bringing fifteen years in chemical processing and an engineering lead role at Mission Zero. The company has also made key hires in other positions.
The company's stated plan has three parts.
Build: An industrial pilot facility in West London, targeting five tonnes of hydrogen a year, funded by the seed round.
Prove: Reach technology readiness level 6 by 2027, the point at which a process has been demonstrated in a relevant environment rather than a lab.
Sell: Convert the letters of intent into supply contracts with e-fuels producers making e-SAF, e-methanol and e-methane.
Carbon13's SEIS fund put £119,999 into Ki's pre-seed round in September 2023. For that investment, the fund holds 154,638 shares in Ki, presently accounting for around 5.83% of the business.
Since that first round, Ki has raised three more times, and each round has priced the shares higher than the one before: £1.455 and £1.746 in the 2023 pre-seed, £5.446 when HICO led in November 2025, and £6.051 in the 2026 seed tranches. That's how the holding got to where it is.
At the current £6.051 price, Carbon13's shares are worth £623,810. That's 5.20 times the £119,999 paid, gross of fees, unrealised, and measured only from Carbon13's own entry price.
A 5.2 times increase over three years is nothing to sniff at but it's also worth being clear. This is growth in the share price of a private company, not a return on capital, and the value can fall as easily as it's risen.
KI HYDROGEN LTD, company number 14525660, incorporated 6 December 2022. Nominal value £0.00001 throughout; no subdivisions or consolidations.
Allotment date | Shares | Price | Amount | Class | Who |
8 Sep 2023 | 154,638 | £1.164 | £119,999 | A ordinary | Carbon13 ASA converts |
8 Sep 2023 | 167,009 | £1.455 | £242,998 | A ordinary | Angels |
20 Nov 2023 | 176,632 | £1.455 | £257,000 | A ordinary | Mostly Angels |
20 Nov 2023 | 148,911 | £1.746 | £259,999 | A ordinary | G-Force Fund II SLP |
27 Nov 2025 | 413,147 | £5.446 | £2,249,999 | Seed | HICO, GiTV Desai |
24 Jun 2026 | 8,263 | £6.051 | £49,999 | Seed | Follow-on investment |
6 Aug 2026 | 82,630 | £6.051 | £499,994 | Seed | Follow-on investment |
Source: Companies House filings. Nominal value £0.00001 throughout; no share splits or consolidations have occurred, so all prices are directly comparable. These are the prices at which shares were allotted in each round. The share price of a private company is not a market price and can fall as easily as it has risen. Carbon13's £1.164 entry reflects an advance subscription agreement converting at a 20% discount to the £1.455 round price; it is not a separate round price.
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