Low consumption direct air capture and low water consumption (DAC) in Israel

This article is one of a series about Israel’s ClimateTech ecosystem and some of its innovative businesses. Read this introductory article for an overview of the public-private partnership at the heart of Israel’s ClimateTech, and this article to learn about CENS Nano, a company using nanotechnology to significantly improve lithium-ion batteries.

Readers of this column know that I have been interested in direct air capture (DAC) technology for several years. Lately though, my views on DAC have become a bit more nuanced. I continue to see the need for the technology given the hole we’ve dug ourselves into in terms of atmospheric carbon dioxide levels, but the economics behind using DAC resources are starting to bother me more and more.

Liquid sorbent-based DAC systems require a lot of energy and a lot of water. Eventually, energy demands will be able to be met by a grid of renewables (or perhaps dedicated small nuclear plants), but there is a lot of infrastructure to be built and even that construction will not happen overnight. When it comes to water, every gallon used for DAC is a gallon that cannot be used for agriculture or human use in a hotter, drier world.

Knowing these sink-based DAC weaknesses, imagine how interested I was when I saw a pitch deck from Israel RepAir Carbon suggesting it had technology for a DAC solution that could run on much less energy and water.

Speaking with RepAir CEO Amir Shiner piqued my interest even more.

RepAir has an exclusive, worldwide license to technology developed by Dr. Yushan Yan, the Henry B. du Pont Professor of Chemistry at the University of Delaware. The technology of Dr. Yan is based on research into a proprietary membrane chemistry that can filter low-concentration atmospheric CO2 from ambient (ie, uncompressed, room-temperature) air.

Because the system does not use high temperatures to remove CO2 from the air, each unit is expected to use nearly 70% less energy than DAC liquid sorbent systems. Also, since the air has a certain minimum level of humidity, no additional water is needed. In a dry environment, you just need enough water to pass the moisture threshold. From a resource usage point of view, this is a very attractive feature!

The more Shiner told me about the idea, the more it sounded like a fuel cell. In fact, the concept was inspired by hydrogen fuel cells and has some similarities in design, and the company is modifying electrolyte membranes in its development work to this day.

Shiner tells me that, like a rechargeable battery, the RepAir units reverse polarity every now and then – the side that was pulling in ambient air becomes the side that’s pushing out pure CO2, and the side that handled CO2 is reversed as air intake. However, even with this change, the CO2 separation process is essentially continuous.

The design of the RepAir system is modular, so customers will be able to simply stack them together to collect more CO2. Because temperatures remain low during the process, the materials used for the system are abundant, low-cost metals and polymers.

The only piece of equipment that will require development work to scale is the membrane – it really is RepAir’s secret sauce. Shiner says the company’s scientists and engineers are experimenting with different membranes based on slightly different chemistries and are talking with membrane suppliers about the requirements to build the units at scale.

Before you get too excited about this idea, the important thing to remember is that RepAir’s technology is still pretty early in development and is still working as a lab prototype right now.

The company has raised investment money from Israeli and UK venture capital firms and received a grant from the Israel Innovation Authority (IIA) as well as some acceleration money. The seed capital of $1.5 million allowed the RepAir team to begin staffing with engineers, materials scientists, chemists and business development people.

Shiner is in the final stages of discussions with several top investors to close an 8-figure Series A round very soon. With this investment money, the next step is to move the RepAir device from the lab to real-world conditions and testing various membrane design configurations and prototypes in different environments.

In short, there is still a lot of work to be done, but Shiner is excited that because the membrane system designs are based on chemistry that is well known and widely used, the RepAir solution will be able to scale quickly and efficiently.

I also asked my guide at Israeli ClimateTech, Rotem Yehuda Kakon, what he and CPG saw at RepAir.

“At RepAir, we have seen an outstanding team with a strong desire to lead change in the field of DAC, a technology that will play a vital role in limiting global temperature increase to less than 2°C.”

Considering what is at stake – the health of our biosphere and the many benefits of our complex culture – like Kakon, I ask Dr. Yan, Shiner and Team RepAir!

Dr Yan and Mr Shiner know, as I do, that it is not too early to throw everything we have at solving the carbon imbalance we have created for ourselves.

Smart investors take note.