© 2008 by Terry L. Walker, AIA, All rights reserved. This material may not be published, reproduced, broadcast, rewritten or redistributed without permission. All ideas and concepts related to energy storage and regeneration embodied here-in are the intellectual property and invention of Terry L. Walker, AIA.
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TITLE: THE CO2 PUZZLE
What do we do with CO2 emissions to mitigate the global environmental impacts?
CO2 Capture Technologies are currently too expensive.
Carbon Capture Technologies
It is imperative to protect the environment from manmade CO2 and conventional coal plants should not be constructed without carbon capture technologies. Before carbon dioxide (CO2) gas can be sequestered from power plants and other point sources, it must be captured as a relatively pure gas.
Existing capture technologies, however, are not cost-effective when considered in the context of sequestering CO2 from power plants. Currently amine absorbers and cryogenic coolers are used to recover CO2 from combustion exhaust. The cost to capture the CO2 is currently $150.00 per ton or an electricity cost increase of 2.5 cents to 4 cents /kwh depending on the type of process. To make CO2 capture worthwhile it must have a value or other substantial contribution post capture and sequestration, that exceeds the cost recovery of current industrial uses.
To be successful, the techniques and practices to capture and sequester carbon must meet the following requirements:
· be effective and cost-competitive,
· provide stable, long term storage, and
· be environmentally benign.
Three capture technologies and four geologic storage mechanisms are envisaged. These are described and illustrated below:
Considered the first step towards largescale capture, CO2 is removed from
exhaust gas after combustion. This technology can be retrofitted to existing
*Pre-Combustion Decarbonization (Hydrogen) Natural Gas is converted to hydrogen and
CO2 in a reformer. The CO2 is compressed for storage and the hydrogen is mixed
with air for combustion, emitting only nitrogen and water.
Oxygen is separated from air and then burned with hydrocarbons to produce an
exhaust with a high concentration of CO2.
The schematic diagram below illustrates options for geologic storage. Note that some options provide additional energy and the potential to recover the cost of carbon capture.
*CO2 stored in Saline Formations
*CO2 displaces methane from coal
*CO2 stored in depleted Oil / Gas Reservoir
*CO2 displaces trapped Oil (enhanced oil recovery)
Using present technology, estimates of sequestration costs are in the range of $100 to $300/ton of carbon emissions avoided. The goal of the program is to reduce the cost of carbon sequestration to $10 or less per net ton of carbon emissions avoided by 2015. Achieving this goal would save the U.S.trillions of dollars.
No doubt, we can achieve some cost reductions with improved process and technology but the capacity to turn sequestration of CO2 into profits and achieve direct recovery of the cost would be just as good and achieving both would be better.
The key to unlocking the solution to all such problems is embodied not only by what is prevented, in this case a compelling incentive, but more importantly by the more desirable future state that is empowered and the significant additional net value added.
Transition to alternative renewable energy power generation systems and a more desirable, economical and sustainable energy future requires a solution to the problem of energy storage.
We need the missing piece of the puzzle. Fossil fuel needs viable alternatives to replace it’s current role in our civilization. Supercritical CO2 sequestered in depleted oil & gas reservoir following advanced oil recovery processes can be used to store massive amounts of energy because of the energy embodied in the phase change of the CO2 gas to supercritical state. The cost and energy that is invested in the process is of course recoverable and it thereafter empowers unlimited deployment of solar photo-voltaic power plant, wind mill farms and small scale hydro. In the short term such a strategy empowers economic justification for carbon capture and sequestration.
THE MISSING PIECE
Energy Storage and Regeneration.
Solution; Massive energy storage capacities from sequestered supercritical CO2.
I would like to discuss the invention with DOE and work with DOE to determine the
feasibility of the idea. I am not affiliated with any University or National Laboratory. I have
limited experience working with Federal agencies and would appreciate advice regarding
how best to proceed.
I am an architect with considerable engineering experience. I appreciate your time and
interest and would request a response from an individual with appropriate technical
expertise regarding this concept. Please find below my contact information and a link to my
Terry L. Walker, AIA
21712 21st Ave. West
Brier, WA 98036
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Walker Architects, A premier architectural service provider located in the Seattle, Washington Area..