Andrew,
Yes. Scaling the floating (or submerged) shipping , storage, and gas-to-liquid conversion facilities may limit how fast we can get OMA to replace all fossil fuel use and reduce atmospheric CO2 concentrations. Luckily, OMA is unusual in that it is sustainable at the necessary scale to justify the facilities. The Life Cycle Assessment was based on moving the bio-methane to a floating offshore power plant with a 100 kilometer direct current cable connection to the grid. We could use many more scenarios for forest design and transportation.
It should take a decade or so of full-scale operations (many 10,000 ha forests) to achieve the Life Cycle Assessment cost estimates. We do expect methane costs less than or equal to fracking produced natural gas at the well head. (Not allowing for the cost of fracking to increase with (necessary) regulation.) If we don't have a resonable premium for bio-methane over natural gas in a decade, we are doomed to more drastic measures.
Also, we already go to the trouble of liquifying methane for shipping. Liquified natural gas (LNG) export, import, and associated tankers already exist. A decade ago the US was importing. Today the US is exporting. Tremendous natural gas infrastructure already exists. Cheap (hydrofractured) natural gas is displacing coal-fired electricity in the US.
Plus, facilities for converting natural gas in liquid fuels and chemicals are in planning and under construction. See http://www.statoil.com/en/TechnologyInnovation/gas/GasLiquidsGTL/Pages/GasToLiquid.aspx.
Natural gas is a boom-bust fuel. When plentiful, we build facilities to use it preferentially to less clean burning and higher carbon coal and oil. Prices rise, facility construction slows, we find more, prices drop, facility construction increases, we use it up a lot faster than anticipated, prices rise, .... The trick is to develop and deploy the OMA now, so that it is ready for the next upswing in natural gas.prices.
Mark
---------- Original Message --------
Subject: Re: [geo] Negative carbon via Ocean Afforestation
From: Andrew Lockley <[email protected]>
Date: Wed, January 09, 2013 5:25 pm
To: [email protected]
Cc: geoengineering <[email protected]>
Methane is flared around the world by the oil industry as a useless by
product. Such flaring is generally limited by environmental
legislation rather than the existence of viable markets. Even
reasonably large methane sources close to population centres are
flared off, such as in the Niger delta. Methane sources have to be
very large and well-connected to established markets before they can
be assumed to be viable for commercial exploitation. Alternatively,
you'd have to build power stations custom-designed to use your
feedstock, or the methane from it.
I think that animal feed might be a better use for your products.
However, ruminants will do a pretty good job of turning it back into
high CO2e methane and releasing it!
A
On 9 January 2013 15:22, <[email protected]> wrote:
> Andrew,
>
> Ocean Macroalgal Afforestation is more of a concept revival with better
> technology and increased urgency than a new idea. The paper is vetted by
> co-author David Chynoweth, who has decades of research on seaweed to energy.
> I confess to also being a co-author.
>
> You hit the key question: At what scale do demand limitations kick-in?
>
> First note that demand (not sustainability) is limiting because the
> ecosystem scales beyond 9% of the world ocean surface with environmental
> benefits defined by increased biodiversity and primary productivity. Unlike
> most biomass-to-energy or BECCS, Ocean Afforestation is not limited by
> nutrient recycling at any steady-state situation. (No free-lunch. OMA is
> solar powered.)
>
> In the paper, and the six supplements, we limited the extent of Ocean
> Afforestation to 9% of ocean surface because that area corresponds to a
> reasonable estimate of total world fossil energy demand in 2030. It seems
> reasonable that the demand for bio-methane is the demand limitation because
> the process is funded primarily from biomethane sales.
>
> Mark E. Capron, PE
> Oxnard, California
> www.PODenergy.org
>
>
>
> -------- Original Message --------
> Subject: [geo] Negative carbon via Ocean Afforestation
> From: Andrew Lockley <[email protected]>
> Date: Tue, January 08, 2013 8:37 am
> To: geoengineering <[email protected]>
>
> Poster's note: From the abstract this sounds pretty breathless to me.
> I imagine that the economics of scaling will be complex, particularly
> when demand limitations kick in, and transport costs are properly
> factored.
>
> http://www.sciencedirect.com/science/article/pii/S0957582012001206
>
> Negative carbon via Ocean Afforestation
> Antoine de Ramon N‘Yeurta et al
> http://dx.doi.org/10.1016/j.psep.2012.10.008
>
>
> Abstract
> Ocean Afforestation, more precisely Ocean Macroalgal Afforestation
> (OMA), has the potential to reduce atmospheric carbon dioxide
> concentrations through expanding natural populations of macroalgae,
> which absorb carbon dioxide, then are harvested to produce biomethane
> and biocarbon dioxide via anaerobic digestion. The plant nutrients
> remaining after digestion are recycled to expand the algal forest and
> increase fish populations. A mass balance has been calculated from
> known data and applied to produce a life cycle assessment and economic
> analysis. This analysis shows the potential of Ocean Afforestation to
> produce 12 billion tons per year of biomethane while storing 19
> billion tons of CO2 per year directly from biogas production, plus up
> to 34 billion tons per year from carbon capture of the biomethane
> combustion exhaust. These rates are based on macro-algae forests
> covering 9% of the world's ocean surface, which could produce
> sufficient biomethane to replace all of today's needs in fossil fuel
> energy, while removing 53 billion tons of CO2 per year from the
> atmosphere, restoring pre-industrial levels. This amount of biomass
> could also increase sustainable fish production to potentially provide
> 200 kg/yr/person for 10 billion people. Additional benefits are
> reduction in ocean acidification and increased ocean primary
> productivity and biodiversity.
>
> Highlights
> ► Ocean Afforestation concentrates carbon dioxide for storage.
> ► Ocean Afforestation also produces biofuels, food, and biodiversity.
> ► Plant nutrient recycling might sustain the ecosystem to <350 ppm
> carbon dioxide.
> ► Multiple products reduce the cost of sequestering carbon dioxide.
>
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