Waste-to-Hydrogen Technology: Leading the Way to Net Zero?

In West Dunbartonshire lies a parcel of land awaiting ground breaking at a recently confirmed waste-to-hydrogen plant. Operated by Peel NRE, the £20m facility will use technology from Powerhouse Energy Plc (AIM:PHE) to convert non-recyclable plastic waste into electricity and hydrogen.

soft plastic bags

A newcomer to renewable energy, converting waste to hydrogen is a practice now contemplated by several large operators. Simply put, it is the heating and treatment of waste materials to produce pure hydrogen gas usable as energy. Techniques vary, but the premise remains commonplace: productively dispose of non-recyclable waste while increasing the use and availability of hydrogen energy through a low-cost, low-carbon process.

Advanced thermal conversion technology

The AIM:PHE technique uses advanced thermal conversion technology, in which non-recyclable plastics are ground into small, similarly sized pieces and fed into a chamber, ready to be heated to very high temperatures. The plastic is then melted and vaporized into a gas mixture, from which the molecules are reformed to create a synthetic gas (syngas) made up of methane, hydrogen and carbon monoxide. The syngas is collected and used to generate hydrogen and electricity.

Much of the hydrogen produced is planned for use at a hydrogen refueling station on the same site as the plant, operated by Element2, with the capacity to fuel approximately 40 heavy-duty vehicles, 500 buses and 2,500 cars per day.

However, a small portion of the synthesis gas produced is kept to heat the thermal conversion chamber, which means that the process is completely self-sufficient.

With a similar plant under development near Chester, the project will be the second in plans for up to 70 waste-to-hydrogen facilities in the UK, collectively with the capacity to power around five million buses.

microwave catalysis

Further south, researchers from Oxford and Cardiff universities have recently shared information on a new microwave catalysis project. In partnership with CarbonMeta Technologies, the approach uses specialized microwave catalysts to heat materials such as plastics, construction waste and food waste, to separate the hydrogen and carbon in any hydrocarbons found in the feedstock.

The hydrocarbons are processed with microwave radiation, in which the catalyst absorbs the radiation and concentrates it on the bonds that hold the hydrocarbons together. Once these bonds become unstable, the hydrogen is released as a gas, while the carbon remains solid.

Turquoise Hydrogen emerges from processed plastics, named for its similarities to hydrogen produced from natural gas and biogas. It is created here in solid form, preventing the release of CO² if it were to come in gas form.

With plans for a commercial plant processing five tons of plastic to produce 250 kilograms of hydrogen per day by 2023, CarbonMeta Technologies is now focusing on an evaluation project in Spain. Building on previous work in the UK, the project will investigate which combinations of plastic waste can generate the most substantial yields.

Any plastic can be used in the process, CarbonMeta Technologies shares, including HDPE, LDPE, PET, PLA, polystyrene, and even BOPP Goliath plastic films. While some of these materials can be better recycled for reused materials, hard-to-recycle plastics can be easily processed into hydrogen and carbon nanomaterials.

These nanomaterials, including graphite, graphene, and carbon nanotubes found in “amorphous” carbon, will also be marketable, further demonstrating the industrial value of the process.

Speaking to Resource, the association adds: “The future looks particularly bright; The beauty of our innovation is that it provides both turquoise hydrogen from plastic waste and equally important carbon nanomaterials as a co-product. It is about the rise and rise of hydrogen in our future energy mix.”

Plasma assisted gasification

Researchers at Boson Energy in Luxembourg have taken this one step further, formulating a technology that leaves behind secondary materials profitable enough for the project to run at zero or even sub-zero cost.

In the process, plasma-assisted gasification, the reactors are heated with electric plasma torches up to 7,000°C. The shredded waste is fed into the reactor, which is much cooler at the top than at the bottom, and travels through zones of increasing heat, each with its own function.

At the top, the waste is dried and heated, before pyrolysis (decomposition by heat without oxygen) takes place below to produce a mixture of pyrolytic gases (hydrogen, carbon monoxide and light hydrocarbons). The remaining matter is then gasified with steam, which is then combined with pyrolytic gas to create a synthesis gas, a mixture of hydrogen and carbon monoxide. Finally, this is separated by steam reforming and water gas exchange processes.

Together with pure hydrogen, this resulting CO² can be used profitably and sustainably. Most commonly, it is used in food manufacturing, to make carbonated beverages, food packaging, and in greenhouses, and can also be used to cure cement and other building materials, in which CO² is captured and cannot escape.

What remains in the reactor once these gases have been captured, mainly ash and slag, is then heated to a molten state. It then cools and solidifies into an inert glassy rock that the firm calls ‘IMBY’ rock.

With an operational plant already open in Israel, Boson is planning 10 commercial projects across Europe. The expansion will receive funding from the investment portfolio of the European Clean Hydrogen Alliance (ECH2A), which supports more than 750 projects working with the European Commission’s Hydrogen Strategy.

It is clear, then, how converting waste to hydrogen aligns with legislative goals. As for Boson’s ambitions, these facilities will help reach the EU target of producing one million tonnes of renewable hydrogen by 2024, followed by 10 tonnes by 2030.

Similarly, such projects are promising industrial developments in light of Governments’ Hydrogen Strategies and overall climate goals. Launched in April last year, the Hydrogen Strategy aims to guide the country’s hydrogen economy and sector to achieve a low-carbon hydrogen production capacity of 10 GW by 2030, with at least half being electrolytic hydrogen. .

This objective is accompanied by sub-objectives to position the UK at the forefront of the global hydrogen market for wider strategic benefits, while lowering costs and ensuring long-term value for money for consumers. .

In addition, the Energy Security strategy, with a notable focus on the growth of the UK hydrogen industry, aims to return the UK to energy independence as it switches from fossil fuels to newer renewable energy sources. , sites like those soon to be found in West Dunbartonshire. they are making this a more likely reality.

The initiative aims to design new business models for hydrogen storage and transportation infrastructure by 2025 to support the growth of the sector. This is combined with a hydrogen certification scheme, expected in the same year, to demonstrate high-grade British hydrogen for export and ensure that any imported hydrogen meets the same standards as British companies. Ultimately, he sees hydrogen as central to his overall ambitions of net-zero emissions looming by 2050.

CarbonMeta Technologies and Dr. James Edwards, who led the team of researchers from the University of Oxford, highlight the close alliance between the objectives of their project and those of the Government. As testing begins to scale up, the team hopes to reach the hydrogen and net-zero goals sooner.

The fact that these leading projects focus primarily on the use of non-recyclable waste leaves open the question of how expansive the potential feedstock for these processes may be. The question now is how expansive the pool of potential feedstocks for these technologies might be. So far, the aforementioned projects are capable of processing non-recyclable plastics, organic waste, construction waste and waxes. While using these materials would already save tons of residual waste from landfill, there is always room for more.

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