Hi HN!I'm Paul, one of the co-founders of Remora ( Remora is building a device that captures the carbon emissions from a semi truck. Our device mounts between the truck and its trailer, attaches to its tailpipes, and captures at least 80% of its carbon emissions. We will sell the captured carbon dioxide to concrete producers and other end users, helping companies earn new revenue while meeting their climate commitments.We decided to start Remora because we believe electrification won't work for long-haul trucking. Bill Gates agrees: “Even with big breakthroughs in battery technology,” he wrote, “electric vehicles will probably never be a practical solution for things like 18-wheelers" [1].Before Remora, my co-founder, Eric, built hydrogen and electric semi trucks. He saw first hand that these trucks have far less payload capacity and range, plus the batteries lose > 40% of their range in cold weather [2]. We also knew that electrification means building a new network of stations with enough charging capacity for semi trucks, replacing every truck on the road, and overhauling the grid, which is still 63% fossil fuels in the US [3]. So we thought:Why can't we just capture the carbon emissions from the trucks' tailpipes?Turns out, my co-founder, Christina, spent her entire PhD answering this question [3]. Mobile carbon capture was first proposed about a decade ago, but academics dismissed it in favor of stationary carbon capture for power plants. The problem with stationary capture, though, is that it takes tens of millions of dollars upfront to design those systems, and they have to be tailored to a specific plant—it’s impossible to make a cheap, modular unit that can be manufactured at scale.So Christina became the first person to test adsorbents (the materials that selectively capture carbon dioxide) in the specific conditions of diesel exhaust. Surprisingly, the adsorbent that worked best was a naturally-occurring mineral that is cheaply available in mass quantities. Christina built a proof of concept to test in the EPA’s National Vehicle and Fuel Emissions Lab, and it worked.While I was finishing my senior year at Yale, I read Christina’s dissertation online. I called her up to ask a bunch of questions and we hit it off. After more conversations, I wrote her a business plan and convinced her to quit her new job at the EPA to start Remora. Then, we sent a blurb to every professor at the top 15 engineering schools, interviewed ~ 50 engineers, and found Eric.Now, we’ve completed our first working prototype and we’re currently testing it on our truck. Here’s how it works: First, we condition the truck’s exhaust to lower its temperature and humidity, then we run it through a bed of pellets that selectively captures carbon dioxide, letting the other gases escape. When the bed is saturated, we heat the pellets to release the carbon dioxide, which we compress into a tank inside the device. To ensure continuous operation, the device includes two beds: while the first is heated, the truck’s exhaust flows through the second; when the second is saturated, they switch, and so on. This process is very energy efficient because we’re able to use the waste heat from the truck’s exhaust to heat the pellets.Our first units will be capturing carbon dioxide on customers’ trucks by August. By the end of the year, we’ll have 40 units on the road capturing ~ 100 metric tons of carbon dioxide per week—the equivalent of planting 248,000 trees [5]. We will start by selling this carbon dioxide to concrete producers and other end users, but as we grow, we will earn tax credits for permanently sequestering the carbon dioxide deep underground.Long term, if we pair our technology with biofuels, we can make a truck carbon negative. We also hope to apply it to other hard-to-electrify forms of long-haul transportation, like cargo ships.We’re excited to hear your questions, concerns, and feedback! I’ll be responding to comments all day, or please feel free to shoot me an email at hello@remoracarbon.com.[1]     