[GSBN] embodied energy and sequestration

Fri May 7 20:01:57 UTC 2010

Since 1990 I spent a lot of time designing separators for the cement
industry. These dense medium separators at times could handle up to 80 tons
per hours of automobile and industrial shredder residue. Multiple
separations were required to meet the highest safety requirements within
Europe as set by the German government. Instead of putting this organic
material in landfill or incinerating it, it was used to make cement. The BTU
content of this material reached as high as 12,000. When burning this fuel,
the cement kilns were able to make cement at a negative energy cost. The ash
from this organic waste was vitrified and remained harmlessly in the cement.

The heat and residence time in a cement kiln are very high, and the cement
kiln has to be one of the best means of disposing of many types of liquid
and solid wastes. Dumping these wastes in a landfill or incinerating them
are totally inadequate. Cement kilns take in a lot of waste that should go
nowhere else.

I can assure you all that I spend all of my time in the development of
technologies that benefit the environment, and I can state  unequivocally
that a cement kiln is not always a bad thing.

Thanks.
Paul
-- 
Paul A. Olivier
Louisiana telephone: 1-337-447-4124 (rings Vietnam)
Mobile: 063 399 7256 (in Vietnam)
Skype address: Xpolivier
http://www.esrla.com/

On Fri, May 7, 2010 at 7:19 PM, Tom Woolley <tom.woolley at btconnect.com>wrote:

> Dear all
>
> Maybe there is confusion here between cement and lime
>
> Lime can absorb C02 during carbonation and this can make a small
> contribution to carbon sequestration over its life in a building
>
> Cement however does not in most cases as cement works best if it does not
> carbonate unlike lime.
>
> The argument that C02 is stored in concrete is a  bogus argument put about
> by the cement and concrete industry to try and greenwash cement.
> The carbonation argument seems to be based on the idea that concrete can be
> crushed at the end of life and that this has some carbonation benefit
> See
> http://www.sustainableconcrete.org.uk/main.asp?page=85
>
> The C02 is emitted during the manufacture of cement and is not recovered in
> my opinion . It contributes to fossil fuel energy wastage and global warming
> Even the use of recycled material like ash involves energy though the
> cement industry have made great strides in reducing this
>
> Cement manufacture remains one of the highest emitters of C02 in all human
> activity as alternatives are not being used in many parts of the world
>
> Pragmattically we probably all use a bit of cement from time to time but it
> should be avoided if there are better alternatives like lime or earth
> Here is an interesting paper which discusses these issues and compares
> cement to alternatives
>
> http://www.springerlink.com/content/56266t21424h4854/
>
> *Calculation of sequestration  in wood straw etc.*
> *
> *
> *A paper on this is being prepared by David Robson of University of
> Cumbria and initial findings have been presented to the UK Renewable
> Building Group*
> *Several GSBN UK members are part of this group*
> *
> *
> *This research will be made available when complete and will hopefully
> provide some hard data on the sequestration contribution of renewable bio
> based materials*
> *
> *
> *Tom*
> *
> *
> *
> *
> On 7 May 2010, at 04:13, Mészáros Attila wrote:
>
> Dear All,
>
> I completely agree with Derek. Though the amount of the reabsorbed CO2
> could be nearly 50 % of the portland cement's dry mass, the CO2 emission
> during the production is higher than this amount.
> The net CO2 production of portland cement production and curing is
> positive. The whole process does not sink, but produces CO2. It is pure
> chemistry and physics.
>
> So I am really surprised on Martin's info on IPCC's perception.
> I know personaly the hungarian member of IPCC, Diana Ürge-Vorsatz, she
> is also a physisist.
> So if we can have a bit more info, we can act. First informal ways, and
> then even formaly...
>
> Attila
>
> Attila Mészáros
> CEO, CereDom Ltd
> email: meszaros.attila at ceredom.hu
> tel: +36 20 9772258
>
> 2010.05.06. 23:22 keltezéssel, Derek Roff írta:
>
> Thanks, Martin. Could you clarify a bit about this sentence? Do the
>
> sources that you quoted give an explanation?
>
>
> "cement-based products in contrary are accepted to reduce the PCF
>
> (product-carbon-footprint) as the CO2 used for production is stored
>
> for a long time."
>
>
> What I find confusing, is that production of cement produces a lot of
>
> CO2 from fossil fuels in mining, processing, calcining, and utilizing.
>
> It produces/releases a fair amount of sequestered CO2 from the
>
> limestone during the calcining chemical reaction. I'm not thinking of
>
> any point at which "the CO2 used for production" is stored at all. A
>
> small amount of CO2 is reabsorbed from the air by finished concrete,
>
> but what I have read is that this is a tiny fraction, and needs to be
>
> tiny, to maintain the integrity of the concrete.
>
>
> So what CO2 storage are they talking about?
>
>
> Derek
>
>
> --On Thursday, May 6, 2010 9:24 PM +0200 martin oehlmann
>
> <moehlmann at wanadoo.fr> wrote:
>
>
> Dear all,
>
>
> however not much response here on this issue... some possible
>
> interesting observations in the meantime:
>
>
> According the perception of IPCC and UN-FCC straw and wood are not
>
> seen as CO2-sink, yet CO2 neutral, cause of the durability is
>
> “difficult” to calculate. In contrary cement-based products in
>
> contrary are accepted to reduce the PCF (product-carbon-footprint) as
>
> the CO2 used for production is stored for a long time. (source:
>
> Memorandum Product Carbon Footprint, German Ministry for Environment,
>
> Nature Protection etc.)
>
>
> Comment: compliments for the cement lobby, low cost cementbased
>
> massproduction for housing with a lifespan 30-40 years.
>
>
> If planted forests get cut after 30 years and seen as a CO2 sink, a
>
> high quality building which lasts 100 years and longer built with
>
> natural materials better should be perceived as storage, if the
>
> intention from IPCC and UN-FCC is to support sustainable
>
> constructions.
>
>
> Nice day and all the very best,
>
>
> Martin Oehlmann
>
>
> Brittany
>
>
>
>
> Derek Roff
>
> Language Learning Center
>
> Ortega Hall 129, MSC03-2100
>
> University of New Mexico
>
> Albuquerque, NM 87131-0001
>
> 505/277-7368, fax 505/277-3885
>
> Internet: derek at unm.edu
>
>
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>
> Tom Woolley
>
> Rachel Bevan Architects
> 80 Church Road
> Crossgar
> Downpatrick
> BT30 9HR
> tom.woolley at btconnect.com
> 028 44 830988
>
>
>
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