# 24 False CO2 Values Published in Scientific Papers

Technical paper #24

False Values on CO2 Emission for Geopolymer Cement/Concrete Published in Scientific Papers

Adapted from the article originally published in Elsevier’s internet site “Materials Today” at Environmental Implications of Geopolymers, 29 June 2015. See also the presentation at the Geopolymer Camp 2015. See also the news Virtual Journal on Geopolymer Science .

LCA of commercialised geopolymer cement/concretes are seldom. This is due to proprietary reasons. Presently they are based on Type 2 slag/fly ash/alkali-silicate system (see Technical papers #21, #22, #23 in the Library). Geopolymer Type 2 concrete and standard Portland concrete are similar in non- binder materials used and behaviour after production; there is some dilution of the benefits when measured over the full life cycle (LCA). The greenhouse gas emissions during the life cycle of Geopolymer Type 2 concrete are approximately 62%-66% lower than emissions from the reference concrete. The Type 2 geopolymer cement has ca. 80% lower embodied greenhouse gas intensity than an equivalent amount of ordinary Portland cement binder used in reference concrete of a similar strength, confirming the data published by the Geopolymer Institute, where the reductions are in the range of 70 % to 90 % (see Technical paper #21). These values do not include any additional external constraints like transport from or to the utility. They reflect the actual potential as soon as industrialization starts in full swing.

On the opposite, several published scientific LCA papers claim that, in terms of CO2 emission, geopolymer cement was not better than Portland cement, and worse for other parameters. These statements are based on methodological errors and false calculations of the CO2 emission values for geopolymer cement/concrete. The problem is that these false values are taken for granted by other scientists without any further consideration.

The present paper “False Values on CO2 Emission for Geopolymer Cement/Concrete Published in Scientific Papers” cites and explains the methodological errors and false calculations.

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