A startup plans to build a new type of fuel-producing plant in California’s fertile Central Valley that would, if it works as hoped, continually capture and bury carbon dioxide.

The facility, developed by Mote of Los Angeles, would rely on the mounds of agricultural waste produced on the state’s sprawling almond orchards and other types of farms. It would heat leftovers like tree trimmings and fruit pits to temperatures above 1,500 ˚F, hot enough to convert the biomass into hydrogen and carbon dioxide.

Mote plans to separate out the carbon dioxide and pump it deep underground into saline aquifers or retired oil wells near the plant. The hydrogen would be sold to serve the state’s growing fleets of emissions-free buses and trucks.

The process should permanently store away the carbon captured by the plants as they grow. And the hydrogen would defray the high costs of the process.

Mote says its facility would be the first to convert biomass to hydrogen while capturing the carbon emissions. But it’s among a growing number of efforts to commercialize a concept first proposed two decades ago as a means of combating climate change, known as bioenergy with carbon capture and sequestration, or BECCS.

Such operations could remove greenhouse gas from the atmosphere over time, even as they provide low- or no-emissions replacements for fossil fuel. But there are serious challenges to doing it affordably and in ways that reliably suck down significant levels of carbon dioxide.

Dan Sanchez, who runs the Carbon Removal Lab at the University of California, Berkeley, says the process that Mote intends to use, known as biomass gasification, is technically difficult and expensive. It requires careful pre-treatment of the waste and cleaning of the resulting gases. And gathering up the fuels from scattered farms or forests will be complicated and costly.

In addition, the company’s longer-term prospects could be constrained by the lack of infrastructure for moving around and storing the resulting gases, as well as limited demand for the high-cost variety of hydrogen it plans to produce.

But Mote’s plant might be a particularly effective approach to BECCS because the resulting fuel is carbon free, while other types of plants produce fuels that release some amount back in the end.

And Mac Kennedy, the company’s chief executive, says the facility could become profitable within a few years by taking advantage of state subsidies for low-carbon fuels and federal tax credits for carbon storage. He hopes to eventually build more plants across California and beyond, potentially tapping into other fuel sources like trees removed from forests, whether in the aftermath of wildfires or in the hopes of preventing them.

Tricky questions

BECCS is a loosely defined technology that can include facilities running on wood chips, switchgrass, or municipal waste, and producing electricity, ethanol, or so-called synthetic fuels that can power today’s cars, trucks, and planes.

The concept has seized a growing share of attention in research and policy discussions as climate models increasingly find that the only way to avoid very dangerous levels of warming this century is to suck vast amounts of greenhouse gases from the atmosphere.

Plants and trees do a great job at that, but when they die, rot, or burn, much of the carbon is returned to the air. Various BECCS schemes promise to “make sure it’s permanently out of the atmosphere,” says Roger Aines, who leads the Carbon Initiative at Lawrence Livermore National Laboratory.

The planned hydrogen plan will “gasify” tree trimmings and other agricultural byproducts.COURTESY: MOTE

The hope is that these operations can be at least carbon neutral, adding no more greenhouse gases they remove. But some promise to draw down much more than is generated, achieving what’s known as negative emissions.

In 2018, the UN’s climate panel concluded that limiting warming to 1.5 ˚C over preindustrial levels could require the removal of as much as 8 billion tons of carbon dioxide per year through BECCS by 2050. Estimates for the technology’s carbon removal capacity vary widely, ranging

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By: James Temple
Title: This fuel plant will use agricultural waste to combat climate change
Sourced From: www.technologyreview.com/2022/02/15/1045317/fuel-plant-agricultural-beccs-waste-climate-change/
Published Date: Tue, 15 Feb 2022 10:00:00 +0000

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