Sustainability-in-Tech : Taking Carbon Out Of … Seawater!

Amsterdam-based startup Brineworks is using innovative seawater electrolysis technology to tackle the issue of carbon emissions and reshape the landscape of carbon capture and sustainable fuel production.

In A Nutshell – Leveraging The Potential of Seawater 

Brineworks has developed a seawater electrolysis technology that extracts carbon dioxide (CO₂) and produces green hydrogen (H₂) directly from seawater. The company’s new approach is different because it leverages the ocean’s higher CO₂ concentration (about 150 times that of the atmosphere), thereby making the process more energy-efficient and cost-effective than traditional air capture methods, all while simultaneously generating green hydrogen as a valuable fuel byproduct.

What Problem Does The Technology Solve? 

Existing traditional direct air capture (DAC) methods (capturing carbon from the atmosphere) are costly and energy-intensive. For example, the International Energy Agency estimates costs between $230 to $630 (€210 to €570) per metric ton of CO₂ for traditional DAC methods. These high costs have, until now, been a significant barrier to large-scale adoption and meaningful impact on global emissions.

Brineworks’ Affordable Seawater Electrolysis 

Brineworks aims to disrupt this landscape by capturing CO₂ directly from seawater at under $100 per metric ton when scaled. Given that the ocean holds CO₂ concentrations about 150 times higher than the atmosphere, the energy required for extraction is substantially less. This makes the process not only more efficient but also more economically viable.

How It Works (Acidifying and Neutralising Seawater for CO₂ Extraction) 

The core of Brineworks’ technology lies in its innovative seawater electrolyser. Electrolysing seawater essentially involves passing an electric current through it, which splits it into different components such as hydrogen gas, oxygen, and ions, but essentially two main parts – an acid stream and a base stream. The ‘acid stream’ (i.e. an acidic solution) is used to lower the pH of seawater in a controlled environment to release dissolved carbon dioxide (CO₂). The ‘base stream’ refers to the alkaline solution that results from the same electrolysis process.

The system that Brineworks users, therefore, employs the acid stream from electrolysis to acidify seawater in a ‘closed system’, which liberates pure CO₂. This CO₂ can then be directly extracted and either sequestered for permanent carbon removal or used as a feedstock for producing e-fuels like e-methanol, e-methane, sustainable aviation fuel, and e-diesel.

After CO₂ extraction, the base stream (alkaline) is then used to neutralise the seawater before it’s released back into the ocean, ensuring minimal environmental impact, and maintaining the ocean’s pH balance. This management of seawater chemistry in the process helps prevent any ecological disruption while leveraging the ocean’s natural ability to absorb more CO₂ from the atmosphere, thereby aiding in global carbon reduction efforts.

Co-Production of Green Hydrogen 

An added advantage of Brineworks’ process is the substantial production of green hydrogen during electrolysis. For every ton of CO₂ extracted, significant amounts of H₂ are generated. This hydrogen can be stored and used as a clean energy / fuel source, providing an additional revenue stream, and enhancing the overall efficiency of the system.

Applications

Brineworks’ technology appears to hold real potential for industries that are challenging to electrify, particularly maritime shipping and aviation. For example:

– Maritime shipping is responsible for about 3 per cent of global emissions and relies on high-energy-density fuels for long-haul voyages. Electrification isn’t a feasible solution in the near term. The Brineworks technology could, therefore, supply the essential CO₂ and H₂ feedstocks for producing carbon-neutral e-fuels directly at ports, thereby reducing reliance on fossil fuels and cutting emissions.

– In the aviation industry, large commercial and cargo planes require massive amounts of energy relative to their weight, meaning that full electrification is currently impractical. Sustainable aviation fuels (SAFs) could offer a viable path to decarbonisation but are hindered by high production costs due to expensive feedstocks. By providing affordable CO₂ and H₂, the technology from Brineworks could lower the costs of SAFs, making them a more practical option for the industry.

Ocean-Based CO₂ Removal (Enhancing Natural Sinks) 

Beyond fuel production, Brineworks also supports ocean-based carbon dioxide removal techniques like Direct Ocean Capture (DOC) and Ocean Alkalinity Enhancement (OAE). These methods enhance the ocean’s capacity to absorb atmospheric CO₂ and combat ocean acidification. Brineworks’ technology provides a versatile and cost-effective means to implement these strategies at scale. For example:

– Direct Ocean Capture (DOC). By adjusting seawater chemistry through acidification and neutralisation, Brineworks can remove CO₂ from seawater, which is then replenished by atmospheric CO₂, effectively reducing greenhouse gases.

– Ocean Alkalinity Enhancement (OAE). The base stream from electrolysis is added to the ocean, increasing its alkalinity, and enhancing its ability to store CO₂ in a stable, dissolved form.

Scaling and Sustainability 

Brineworks is also keen to emphasise the scalability and sustainability in its design. The modular system uses earth-abundant, low-cost materials, thereby reducing capital expenditure (CAPEX) and maintenance costs. High-efficiency membranes and a reduction in precious metal usage also make the technology more accessible and easier to deploy in various settings.

By making the process decentralised, sustainable fuel production can occur anywhere there’s seawater, thereby freeing industries from reliance on geopolitical supply chains of fossil fuels. This could open up possibilities for nations worldwide to produce their own sustainable fuels, contributing to global decarbonisation efforts.

Not The Only Company Doing It 

It should be noted here that Brineworks isn’t the only company / organisation developing seawater electrolysis technology that uses ocean as a source for both carbon capture and green hydrogen production. Others with similar systems include:

– Los Angeles-based ‘Equatic’, which is a leading player in this space, utilising a seawater electrolysis process to simultaneously capture CO₂ from the atmosphere and produce hydrogen. Their technology involves oxygen-selective anodes (OSAs), which allow for efficient hydrogen production without producing harmful chlorine gas. Like Brineworks, Equatic’s process is designed to operate at a cost of under $100 per tonne of CO₂ removed, and they have major projects planned for commercial-scale carbon removal and hydrogen production.

– University of Adelaide researchers have also developed a method to split seawater into hydrogen and oxygen with nearly 100 per cent efficiency. Their approach does not require any pre-treatment, such as desalination or purification, making it a highly efficient and scalable option for green hydrogen production.

What Does This Mean For Your Organisation? 

Brineworks’ innovative approach to carbon capture through seawater electrolysis represents a significant leap forward in the race toward sustainable energy and emissions reduction. By harnessing the ocean’s higher carbon dioxide concentration, the company has developed a method that is not only more energy-efficient but also economically viable. The dual benefit of extracting CO₂ and producing green hydrogen simultaneously positions Brineworks as a key player in decarbonisation efforts, particularly in sectors like shipping and aviation, where electrification remains impractical due to the high energy demands of long-haul operations. The production of synthetic fuels such as e-methanol and e-diesel, using Brineworks’ CO₂ and hydrogen feedstocks, provides a viable solution for these industries to reduce emissions without compromising operational efficiency.

In maritime shipping, which accounts for 3 per cent of global emissions, Brineworks’ technology offers the potential for significant emission reductions by providing ports with the ability to produce carbon-neutral fuels on-site, minimising reliance on fossil fuels. Similarly, aviation (which faces immense challenges in full electrification) could benefit from cheaper and more accessible Sustainable Aviation Fuels (SAFs) made possible by the lower-cost feedstocks Brineworks provides. These fuels may be critical to reducing the carbon footprint of an industry that is responsible for a significant share of global emissions.

What sets Brineworks apart is its ability to achieve large-scale carbon removal while maintaining environmental integrity, ensuring that the delicate balance of ocean chemistry remains intact. This forward-thinking technology, which supports both direct CO₂ extraction and ocean-based carbon removal techniques, offers a sustainable, modular solution that can be deployed globally. In addition to shipping and aviation, industries such as energy production and heavy manufacturing could benefit from the technology’s ability to co-generate green hydrogen, enabling a transition away from fossil fuels while supporting energy storage and production needs.