Reversing Combustion - Can Capturing Carbon from the Air beat Photosynthesis?

Is Capturing Carbon from the Air Practical? | MIT Technology Review

Peter Eisenberger had expected colleagues to react to his idea with skepticism. He was claiming, after all, to have invented a machine that could clean the atmosphere of its excess carbon dioxide, making the gas into fuel or storing it underground. And the Columbia University scientist was aware that naming his two-year-old startup Global Thermostat hadn’t exactly been an exercise in humility.

Peter Eisenberger and Graciela Chichilnisky are adamant about the importance of sucking CO₂ out of the atmosphere rather than focusing entirely on capturing it from coal plants. In 2010, the pair developed a version of their technology that mixes air with flue gas from a coal or gas-fired power plant. That approach provides a source of steam while capturing both atmospheric carbon and new emissions. It also could lower costs by providing a higher concentration of CO₂ for the machine to capture. “It’s a very impressive system, a triumph,” says Socolow, who thinks scientific advances made in air capture will eventually be used primarily on coal and gas power plants.

Such an application could play a critical role in cleaning up greenhouse gas emissions. But Eisenberger has revealed even loftier goals. A patent granted to him and Chichilnisky in 2008 described air capture technology as, among other things, “a global thermostat for controlling average temperature of a planet’s atmosphere.”
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The obvious need for the technology has enticed several other efforts to come up with various approaches that might be practical. For example, Climate Carbon Engineering, based in Calgary, captures carbon using a liquid solution of sodium hydroxide, a well-established industrial technique. A firm cofounded by an early pioneer of the idea, Eisenberg’s Columbia colleague Klaus Lackner, worked on the problem for several years before giving up in 2012.

Team | GlobalThermostat

First Carbon Capture Projects Mask a Lack of Progress | MIT Technology Review

The most significant recent advance was the opening of a 110-megawatt coal power and CCS plant in Saskatchewan, called Boundary Dam, built by the provincial utility SaskPower (see “In a First, Commercial Coal Plant Buries Its CO2”). Michael Monea, president of SaskPower’s carbon capture and storage initiatives, spoke with almost religious fervor at the conference about the project, which will capture 90 percent of its carbon dioxide. “Build more of them, build them bigger, and it will have an effect on the world—I believe that,” he said.
That plant will use the CO2 it captures to help push more oil out of the ground, a process called enhanced oil recovery, or EOR. The sale of the carbon dioxide for EOR is a key mechanism to financing early CCS projects, but this application of carbon burial tends to perpetuate the problem.
“We’re lucky we have these commercial units at all,” says Gary Rochelle, a chemical engineer at the University of Texas, Austin, who is working on a carbon capture project at a coal plant south of Houston. “A few folks have stepped out and are taking risks, and EOR enables them to do it.”

Out of Thin Air: The Quest to Capture Carbon Dioxide

Capturing Carbon Dioxide From Air - 7b1.pdf

Klaus S. Lackner (kl2010@columbia.edu; 212-854-0304)

Patrick Grimes (pgrimes@worldnet.att.net; 908-232-1134)

Hans-J. Ziock (ziock@lanl.gov; 505-667-7265)

Abstract

The goal of carbon sequestration is to take CO2 that would otherwise accumulate in the atmosphere and put it in safe and permanent storage. Most proposed methods would capture CO2 from concentrated sources like power plants. Indeed, on-site capture is the most sensible approach for large sources and initially offers the most cost-effective avenue to sequestration. For distributed, mobile sources like cars, on-board capture at affordable cost would not be feasible. Yet, in order to stabilize atmospheric levels of CO2, these emissions, too, will need to be curtailed.

This paper suggests that extraction of CO2 from air could provide a viable and cost-effective alternative to changing the transportation infrastructure to non-carbonaceous fuels. Ambient CO2 in the air could be removed from natural airflow passing over absorber surfaces. The CO2 captured would compensate for CO2 emission from power generation two orders of magnitude larger than the power, which could have instead been extracted from the same airflow by a windmill of similar size.

We outline several approaches, and show that the major cost is in the sorbent recovery and not in the capture process. Air extraction is an appealing concept, because it separates the source from disposal. One could collect CO2 after the fact and from any source. Air extraction could reduce atmospheric CO2 levels without making the existing energy or transportation infrastructure obsolete. There would be no need for a network of pipelines shipping CO2 from its source to its disposal site. The atmosphere would act as a temporary storage and transport system. We will discuss the potential impact of such a technology on the climate change debate and outline how such an approach could actually be implemented.

ZECA Corporation, "Zero Emission Carbon (ZEC) Hydrogen and Carbon Dioxide Production Concepts", Stanford April 2004.pdf