Greenhouse-gas emissions, largely responsible for increases in temperature globally, may happen in a multitude of ways. The combustion of hydrocarbons will release carbon dioxide, a prominent greenhouse-gas, as will the reactions of molecular oxygen to chemicals such as formaldehyde and carbon monoxide. Additionally, use of a chemical solvent in the form of carbon tetrachloride, which may also be used in other functions, is considered a greenhouse-gas emission. Though these are all methods of greenhouse-gas emission, a perhaps less familiar method of greenhouse-gas emission is through concrete production, which could benefit from a decrease in associated greenhouse-gas emission.
An article on sciencedaily.org, an American scientific news website,
not only quantified the greenhouse-gas emission of concrete production with a
“5-10 percent of industrial greenhouse- gas emissions” estimate, but also
described a method of producing concrete that will hopefully result in a
decrease of greenhouse-gas emissions as one consequence. The article was based
off a publication in Nature
Communications by Pellenq, et al. and the method involved making the
calcium to silica ratio 1.5 in cement, a component of concrete. This ratio was
determined from analyzing atomic structures and was proclaimed to decrease
carbon emissions by up to 60 percent and strengthen the concrete.
The article agreed well with the Nature
Communications publication at certain major points. In terms of making concrete stronger, clarity
in qualifying concrete strength using terms such as “tightly ordered
crystalline structure” and “disordered glassy structure” helped in tying the
article to the atomic models described in the Nature Communications publication. Additionally, the article did
acknowledge that the study was done on an atomic scale with a goal of
eventually applying it to a larger scale, which was reminiscent of the Nature Communications publication yet a
good alternative to fully describing its dense methodological details.
The article did fall short in a few regards though. What I could not
understand from the article was the link, scientific or not, between a chemical
ratio and lower carbon emissions; the article just mentioned that the “decarbonation
of limestone, and the heating of cement” contributed greatly to greenhouse-gas emissions.
The article could have included some additional information from the Nature Communications publication, such
as the mention of a good calcium to silica ratio in reducing production waste
and therefore carbon emissions, to help with this. Additionally, I thought the
article used some emotion to upgrade the importance of cement by including
phrases such as “no other solution” and “magic” to describe it.
Overall, the article did a good job of communicating the findings in
the Nature Communications publication
succinctly to an audience reading the environment section of a news website. This
was definitely not easy given the ten pages of the Nature Communications publication along with its dense methodologies.
However, I thought the article left out a bit of important information and had
an emotional component as described previously. For these reasons, I would give
the article a score of 7/10.
Links:
Sciencedaily.org article:
Original Journal (Nature
Communications) article:
Wow, it seems that greenhouse-gas emissions can sneak up from anywhere. This is an interesting tidbit to keep in mind.
ReplyDeleteI particularly think this sciencedaily article made a great choice in it's length. I was even discouraged to read the original article due to it's depth in the material.
This greener cement idea (to me at least) seems to be one of those topics that doesn't require a general reader to have to understand the chemistry. They (for the most part) just need to understand that concrete production produces greenhouse gases. Or maybe I'm oversimplifying it!
I agree; the article overall did a good job of summarizing the information for the general audience reading an environmental section of news. The bottom line of the article that people would care about was communicated well.
DeleteI think it is an interesting topic since it could be another way to reduce greenhouse gas emissions. However, I am wondering if there will be any side effect of concrete, like if there are other chemicals emissions which also affects the environment.
ReplyDeleteI think there would be side effects of the new method of concrete production proposed by the article. Lowering the calcium to silica ratio in cement would increase the amount of silica in any given concrete. This could cause health problems because high levels of silica have been shown to cause a variety of respiratory illnesses, such as silicosis (simple and complicated forms of it), silicotuberculosis and silicoproteinosis. However, probably the health concerns of this may be offset by the fact that stronger concrete can be produced so the total amount of waste and (potential silica) resulting from the process can be reduced.
DeleteI just wanted to mention too that I learned about such diseases caused by silica through EHS 501.
DeleteIt's incredible how much of a difference 1.7 to 1.5 calcium to silica can make. I also wonder how consistent cement mixing machines are at getting a set ratio, or do are they just generally in the range of 1.2 to 2.2.
ReplyDeleteI think this is a very good point of consideration.
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