Carbon Recycling Cheat Sheet

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With the American Clean Energy and Security Act making its way to the Senate after a narrow victory in the House, the fate of our relationship with carbon dioxide may soon be decided.

Of the various ways the bill looks to change the nature of how to deal with carbon emissions, cap-and-trade will form the basic structure if the landmark legislation is passed. In essence, the cap-and-trade system will distribute permits to pollute—at no cost initially—to any company that emits carbon dioxide (the cap).

Photo: Grokscience.wordpress.com

According to the Department of Energy, in 1999, estimated emissions of CO2 in the U.S. resulting from the generation of electric power were 2,245 million metric tons, an increase of 1.4 percent from the 2,215 million metric tons in 1998. Photo: Grokscience.wordpress.com

Because the cap, or upper limit, of carbon dioxide emissions is to decrease with time, this spurs companies to reduce their carbon emissions. If a company has leftover permits to pollute that they are not using, they can then sell them to other companies (the trade).

To meet the regulations of the cap-and-trade system, reducing carbon emissions by utilizing alternative forms of energy such as wind, solar and geothermal will be a must.

And while the world waits for renewable energy technologies to catch up with the energy establishment of coal and petroleum, dealing with the interim greenhouse gas emissions will be crucial.

Carbon Capture and Sequestration vs. Carbon Recycling

To remove and reuse the carbon dioxide emissions associated with the modern world’s energy appetite, experts are stressing the continued research and development of carbon capture and sequestration (CCS) systems, as well as a renewed focus on carbon recycling technologies.

Carbon capture and sequestration (CCS) has been at the forefront of up-and-coming technologies when it comes to ridding the atmosphere of human-made greenhouse gases (GHGs). In theory, CCS takes carbon dioxide emitted from the source, typically coal-fired power plants, compresses the gas and injects it deep underground in subsurface geological formations for “indefinite isolation from the atmosphere,” according to the World Resources Institute.

Another prominent GHG-capturing technology is called carbon recycling. In short, carbon recycling takes carbon dioxide emissions and transforms them into a liquid hydrocarbon fuel source. As opposed to CCS, carbon recycling captures and utilizes the carbon emitted from sources such as power plants by making diesel and jet fuel.

It has recently been touted as a viable alternative because advancements in the carbon dioxide gas to hydrocarbon liquid chemical process have become less energetically expensive than in the past.

There are currently three main types of carbon recycling:

  • Biochemical conversion of CO2 into algal biofuel
  • The thermochemical conversion of CO2 into methanol
  • The biocatalytic or solar photocatalytic conversion of CO2 to hydrocarbon fuels

CCS diagram

Stages of Development

With the Obama administration, financial and political support for CCS is at an all-time high. Hailed by many as the path to producing “clean coal,” there are currently about 100 research projects pertaining to CCS in progress around the U.S. and funded by the Department of Energy.

One such project, called FutureGen, has been reinstated under the American Recovery and Reinvestment Act and is dedicated to advancing clean coal technologies as part of President Obama’s overarching plan to create jobs, develop clean energy and act on climate change.

The idea behind FutureGen is to be a model of on-site CCS: create a coal-fired power plant that emits none of the carbon dioxide it produces, instead pumping all of its emissions into the ground.

However, problems abound with CCS. For one, no full-scale CCS model has yet been developed anywhere in the world, so predicting sequestration outcomes remains difficult. Also, costs are a huge issue. The FutureGen project is projected to cost the government about $1 billion, with a consortium of coal producers and users contributing another $400-600 million. With costs this high and commercial viability another 10-20 years away, alternatives to CCS are key if carbon emissions are to be kept in check.

Other issues with CCS include the lack of data about what might happen once carbon is stored underground, as well as the lack of regulation outlining who would be responsible if a carbon leak were to occur.

Although it offers promise, carbon recycling is in the prototype stages as well. And although the green energy field may understand the problems associated with CCS, carbon recycling is still a newcomer to the scene, looking to be taken more seriously.

One advantage to carbon recycling is that it does not require the site-specific geologic formations that CCS systems need so they can pump carbon into the ground. Carbon recycling operations can essentially set up shop anywhere there is a business opportunity.

Which to Support?

The issues related to CCS and carbon recycling recently prompted a U.S. Senate hearing to discuss the various technological paths to pursue in dealing with CO2 emissions.

Margie Tatro, the director of fuel and water systems at Sandia National Laboratories, testified about the benefits of carbon recycling over that of CCS and warned that the U.S. must spur development in the carbon recycling arena to keep pace with the rest of the world.

In the hearing, Tatro outlined why carbon recycling should be pursued as part of a suite of carbon management options:

  • Carbon recycling can help with the two biggest energy challenges facing the U.S. and the world: stabilize the concentration of CO2 in the atmosphere and produce new supplies of liquid hydrocarbon fuels that help reduce the dependence on petroleum.
  • Liquid hydrocarbon fuels derived from CO2 emissions are compatible with the existing infrastructure at the scales and efficiencies necessary to meet large demands.
  • Carbon recycling helps reuse and recycle carbon dioxide. These are two options in what Tatro calls the carbon management toolbox of reducing, extracting, reusing, recycling or burying.

Leaders of the Pack

Carbon Sciences is a U.S.-based company out of Santa Barbara, Calif. The company has developed a laboratory-scale prototype that turns CO2 into liquid fuels such as methanol, jet fuel and diesel. President Byron Elton says the creation of gasoline would be the “holy grail” of carbon recycling.

To get liquid fuel from gas, CO2 needs to be broken up so as to extract the carbon atoms in order to make new hydrocarbons (the building blocks of fuel). Since carbon dioxide is an extremely stable molecule, it takes a lot of energy to break its bonds. That energy requirement to break up carbon dioxide made carbon recycling uneconomical in the past.

However, Carbon Sciences has developed a highly scalable process that provides a protected environment to organic biocatalysts, where they can go about converting CO2 into liquid fuels many times over with out “dying.” By using renewable biomolecules, instead of expensive and mined inorganic materials—such as zinc, gold or zeolite—to catalyze the chemical processes, Carbon Science claims its process is less expensive than the carbon recycling of the past. Additionally, the whole process occurs at low temperature and low pressure, thereby requiring far less energy than other approaches.

The company plans to have a scalable operation within at least two years, suggesting that carbon recycling is a viable, quicker alternative and supplement to the larger-scale and slower moving technologies related to carbon capture and sequestration.

And by taking carbon dioxide from the atmosphere and putting it to use by reusing it in another form, perhaps it will help curb the need to drill for additional fossil fuels and bring the world one step closer to solving its carbon crisis.

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