Some Pieces of Good News on the Environmental Front.

[studiot]

Earlier this year I watched the BBC Earth series, presented by Chris Packham.

One new theory was presented of many years of almost continuous rain on the early basalt eruption surfaces, leading to chemical weathering of the basalt removing significant quantities of acid greenhouse gases, particularly carbon dioxide, from the atmoushphere and chemically 'fixing' it into the ground.

Last Sunday the BBC Countryfile programme had an article about trail replication of this process by spreading the waste products of the aggregate industry (ground up basalt) onto farmland.
The greatly increased active surface of such basalt powder not only reacts quite quickly (ie at human timescales) not only fixing the carbon but also releasing new nutrients to the soil, thereby reducing fertiliser demand.

It is too early to tell just how good this since trials have been going on for little more than a year but apparantly early results are 'encouraging'.

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Then I see that someone has done something about waste plastic from laboratories, formerly just burned (5.5 million tonnes in the annually), to make recycling possible.

 

Well done Helen. Nice to see up and coming graduates succeeding like this.

Quote

https://www.bbc.co.uk/news/uk-england-bristol-67474579

First ever recycling for hidden plastic lab waste

 

 

[exchemist]

28 minutes ago, studiot said:

Earlier this year I watched the BBC Earth series, presented by Chris Packham.

One new theory was presented of many years of almost continuous rain on the early basalt eruption surfaces, leading to chemical weathering of the basalt removing significant quantities of acid greenhouse gases, particularly carbon dioxide, from the atmoushphere and chemically 'fixing' it into the ground.

Last Sunday the BBC Countryfile programme had an article about trail replication of this process by spreading the waste products of the aggregate industry (ground up basalt) onto farmland.
The greatly increased active surface of such basalt powder not only reacts quite quickly (ie at human timescales) not only fixing the carbon but also releasing new nutrients to the soil, thereby reducing fertiliser demand.

It is too early to tell just how good this since trials have been going on for little more than a year but apparantly early results are 'encouraging'.

******************************************************************************************************************************************************************

Then I see that someone has done something about waste plastic from laboratories, formerly just burned (5.5 million tonnes in the annually), to make recycling possible.

 

Well done Helen. Nice to see up and coming graduates succeeding like this.

 

Interesting. I think I recall an article proposing to use ground up slag from cement kilns and blast furnaces for this. But the snag there is both are intensive CO2-generating processes in the first place, so a bit of Pyrrhic victory.

But what exactly does the aggregate industry comprise and how is it that ground up basalt is a byproduct? This does not sound obvious. 

[mistermack]

You need energy to extract the basalt. You need energy to transport it to a plant. You need energy to grind it up. You need energy to transport it to suitable farm land. And the farmer needs energy to spread it and plough it in. Nearly all of that at present is done using diesel. So at the moment, it's a big waste of time and effort, and probably adding more carbon than it's fixing. 

What it does do, is allow some big carbon-emitting companies to buy "carbon credits" and carry on emitting, while getting a tax break. 

Maybe in the future, when diesel, petrol and gas have genuinely been replaced with renewables or nuclear, the scheme might make a marginal difference. 

[TheVat]

13 minutes ago, mistermack said:

You need energy to extract the basalt. You need energy to transport it to a plant. You need energy to grind it up. You need energy to transport it to suitable farm land. And the farmer needs energy to spread it and plough it in. Nearly all of that at present is done using diesel. So at the moment, it's a big waste of time and effort, and probably adding more carbon than it's fixing. 

Was going to point this out.  

More greenwashing, at this point.  

Really good news for the environment would be masses of people in developed countries bicycling and walking and buying less fungible junk and living in smaller homes and eating more plants,  choices that powerful corporations strenuously want people not to make and fight tooth-and-nail against with enormous campaigns of mass marketing.

Edited November 21, 2023 by TheVat

[studiot]

1 hour ago, mistermack said:

You need energy to extract the basalt. You need energy to transport it to a plant. You need energy to grind it up. You need energy to transport it to suitable farm land. And the farmer needs energy to spread it and plough it in. Nearly all of that at present is done using diesel. So at the moment, it's a big waste of time and effort, and probably adding more carbon than it's fixing. 

What it does do, is allow some big carbon-emitting companies to buy "carbon credits" and carry on emitting, while getting a tax break. 

Maybe in the future, when diesel, petrol and gas have genuinely been replaced with renewables or nuclear, the scheme might make a marginal difference. 

Did I see that knee jerking before you read and investigated

 

my article ?

The ground up basalt is produced anyway. It used to be discarded as slag waste.

It can be spread along with fertiliser don't forget that this is reduced, they mentioned a fig of 25% saving of fertiliser.

 

However I do agree with your point about carbon credit trading.

I regard it a scandal.

 

1 hour ago, TheVat said:

More greenwashing, at this point.  

Really good news for the environment would be masses of people in developed countries bicycling and walking and buying less fungible junk and living in smaller homes and eating more plants,  choices that powerful corporations strenuously want people not to make and fight tooth-and-nail against with enormous campaigns of mass marketing.

 

So are you saying that new improved technology should not be employed even if it brings environmental benefits ?

 

To all

I never said this to be a universal panacea.

In the advertising words of one supermarket, "Every Little Helps"

 

[sethoflagos]

4 hours ago, studiot said:

One new theory was presented of many years of almost continuous rain on the early basalt eruption surfaces, leading to chemical weathering of the basalt removing significant quantities of acid greenhouse gases, particularly carbon dioxide, from the atmoushphere and chemically 'fixing' it into the ground.

The effectiveness of carbon sequestion via weathering of basalt etc. is ultimately limited by actual reaction rates. One only has to consider the rather slow disappearance of such basalt structures as eg the Giant's Causeway (and essentially the entire surface lithosphere of Northern Ireland), Fingal's Cave, Iceland to understand that these carbonation reactions are not lightning fast. Even in finely divided form, a visit to a basaltic black sand beach is scarcely seething with chemical activity.

But that does not make it a factor to be ignored. It cannot be a solution to all our problems but it can help. EDIT: I see @studiot has just made the very same point (simulpost)

I found quite a useful summary of its global relevance at https://www.degruyter.com/document/doi/10.2138/am-2019-6884/html?lang=en. 

Quote

On geologic timescales, silicate weathering is the rate-limiting step of the Urey reaction. Because CO₂ dissolution, carbonic acid dissociation, and the other intermediate reactions occur relatively quickly, the availability of silicate-bound Ca²⁺ (or Mg²⁺) (reaction 1C) is of critical importance. This can be thought of in terms of the seawater’s alkalinity, that is, its ability to neutralize acid. Silicate weathering increases the alkalinity of the seawater that drives carbonate precipitation. Note that any contribution to total alkalinity drives carbonation, thus weathering of Mg-silicate minerals could ultimately drive the formation of Ca-carbonates.

Traditionally, geologists have considered continental rocks to be the primary contribution to global silicate weathering (e.g., Walker et al. 1981; Berner et al. 1983). Continental weathering depends on a sequence of discrete processes. First, continental rocks must be exposed at Earth’s surface. Surface rocks are then physically (or mechanically) weathered, that is, broken apart into smaller pieces. Chemical weathering can then occur on the exposed surfaces (as seen in Fig. 2a), partially dissolving the rock and releasing aqueous ions (i.e., reaction 1C). There is a positive association between physical and chemical weathering– mineral dissolution can contribute to denudation while physical weathering can expose more reactive surface area and facilitate chemical weathering. The ions resulting from weathering are transported by rivers and ultimately delivered to the ocean where they continue along the Urey reaction sequence.

I've wondered for a while whether weathering of the calcium silicate content of concrete had a similar effect, and found an interesting Caltech article at https://www.caltech.edu/about/news/weathering-cement-important-overlooked-sink-carbon-dioxide-53134

 

Quote

Drawing upon field surveys conducted in China coupled with a meta-analysis of previous studies done on cement, a team led by Caltech's Zhu Liu found that between 1930 and 2013, weathering of cement absorbed about 4.5 gigatons of carbon (GtC) from atmospheric CO2.

During the same period, the chemical processes used to produce cement emitted 10.4 GtC. (This figure does not include CO2 released from the use of fossil fuels in the cement manufacturing process, which is difficult to accurately quantify. The electricity needed for cement manufacturing is derived from the consumption of various types of fossil fuels, which emit significantly different quantities of CO2.)

Globally, the carbon uptake by cement materials in 2013 was approximately 2.5 percent of the global CO2 emissions from all industrial processes and fossil-fuel combustion in the same year, which is equivalent to 22.7 percent of the average net global forest sink from 1990 to 2007, according to the study.

 ... which I found quite interesting.

Edited November 21, 2023 by sethoflagos
acknowledgement

[studiot]

19 minutes ago, sethoflagos said:

The effectiveness of carbon sequestion via weathering of basalt etc. is ultimately limited by actual reaction rates. One only has to consider the rather slow disappearance of such basalt structures as eg the Giant's Causeway (and essentially the entire surface lithosphere of Northern Ireland), Fingal's Cave, Iceland to understand that these carbonation reactions are not lightning fast. Even in finely divided form, a visit to a basaltic black sand beach is scarcely seething with chemical activity.

But that does not make it a factor to be ignored. I cannot be a solution to all our problems but it can help.

I found quite a useful summary of its global relevance at https://www.degruyter.com/document/doi/10.2138/am-2019-6884/html?lang=en. 

I've wondered for a while whether weathering of the calcium silicate content of concrete had a similar effect, and found an interesting Caltech article at https://www.caltech.edu/about/news/weathering-cement-important-overlooked-sink-carbon-dioxide-53134

 

 ... which I found quite interesting.

Not in the least bit suprised. +1 for a proper attempt at evaluation.

Chemically basalt is nothing like portland cement concrete, although both are silicates.

As a material basalt is more susciptible to chemical weathering attack, enhanced by subsequent detrimental attack on its own structure (HAC, ASR, Ettringite, Carbonation) and on any embedded ferrous reinforcement.

This is in direct contrast to Roman lime based concrete, which continues to gain strength and hardness forever on a diminishing curve, from the atmouspheric carbon dioxide.

Edited November 21, 2023 by studiot

[mistermack]

1 hour ago, studiot said:

The ground up basalt is produced anyway. It used to be discarded as slag waste.

It can be spread along with fertiliser don't forget that this is reduced, they mentioned a fig of 25% saving of fertiliser.

But to put a dent in the Earth's CO2 would take vast quantities of basalt waste. It doesn't appear to be there, except in small pockets. Most aggregate is limestone, and it's so expensive to shift that it's not economic to truck it more than 30 miles. And that's the good stuff, not the waste. Without the magic taxpayer subsidy of about £100 a ton, this project would be going nowhere. And a ton of dust would have very little effect on an acre of land. 

It might make sense, if there were depleted fields, close to a basalt waste dump. 

The quantities of basalt used are small overall. I had a look on wiki, they say :

According to the USGS, 2006 U.S. crushed stone production was 1.72 billion tonnes valued at $13.8 billion (compared to 1.69 billion tonnes valued at $12.1 billion in 2005), of which limestone was 1,080 million tonnes valued at $8.19 billion from 1,896 quarries, granite was 268 million tonnes valued at $2.59 billion from 378 quarries, traprock was 148 million tonnes valued at $1.04 billion from 355 quarries,

Basalt is one kind of trap rock, so it's not a major player. An article I read about this idea admitted that after stocks of basalt dust were exhausted, it would be necessary to grind mined basalt finely, to keep going.

 

[TheVat]

3 hours ago, studiot said:

So are you saying that new improved technology should not be employed even if it brings environmental benefits ?

To all

I never said this to be a universal panacea.

I would never dismiss the many small tweaks that can add up, and I take your point on promoting small benefits.  Not only for their pragmatic value but also as they foster more public awareness.  I was zooming out a little from the myriad problems, in my post, to convey some caution about the public not falling into the complacent trap of thinking their individual choices aren't as critical to what will be an "all hands on deck" human project.