[snewman]

OP says the lignin is "a waste product from the paper industry" and "majority of lignin is burnt". So it sounds like: currently, grow tree (pulling carbon from the atmosphere), process for paper industry, burn the resulting lignin, carbon returns to atmosphere. With this process: grow tree, process for paper industry, embed lignin in road material. If the lignin remains in the road more-or-less permanently (I asked about this in a separate comment), that sounds like legit removal; the carbon started out in the air and ends up in the road.

[haakonzen]

Yes exactly, that's how we think about it. We are using nature's own capture machine, trees... thanks for this clear explanation :)

[tomsyouruncle]

Maybe the concern others are expressing here can be thought of as the risk of double counting of carbon.

If I run an industrial plant that's currently fuelled by burning waste lignin from the paper industry, and I decide to stop that and install some solar panels instead, it seems reasonable for me to claim that change is carbon negative (i.e. I've reduced carbon emissions).

Now if CarbonCrusher comes along and buys the lignin I no longer need, uses it to build a road, and claims the same carbon saving as I did, we end up double counting.

Which of us is wrong?

[hansarne]

This is a very fair question. We need to be mindful going forward in how we communicate. We can say that our Scope 3 emissions are negative, but scope 1 we are slightly positive (but still much lower than competition) Just to clarify; we go from 7-10kg CO2 positive for traditional methods, to 5 kg negative in two steps; Step one is we reduce emissions from transport, extraction etc because we have a better Crusher which recycles the road better, which takes us to just above 1kg pr m2 - massive savings already from the traditional method, and this could be counted mostly in Scope 1 or 2, some of it in 3 (reduced extraction). The remaining ca -6 kg is the effect of lignin - here debated in the thread and that we are saying is carbon negative. This is a scope 3 effect.

Thanks for pointing out! We are still a young company and need to work on our Scope 1-3 accounting :)

[tomsyouruncle]

Thanks a lot for adding these details about scoping[0]. I’ve definitely learned something there.

So my scope 1 emissions can be your scope 3 emissions if I emit carbon to make something that I sell to you… but the “real” emissions are always _somebody’s_ scope 1. Interesting stuff!

[0]: https://www.carbontrust.com/resources/briefing-what-are-scop...

[anamax]

You're switching contexts.

When you switched from burning lignin to solar, you reduced your carbon usage.

However, what happened to the lignin that you stopped using?

If it was burned somewhere else, the total carbon usage remained the same even though you changed your usage.

If it was stockpiled and is now decomposing over three years, the carbon usage was time-shifted and will be back where it was in three years. (However, total carbon usage will be reduced the first and second year.)

This is supposedly a usage of lignin that results in no release, so it actually is carbon-negative (assuming that the processing doesn't use more carbon), regardless of what other folks think that they did. That said, it's probably actually just time-shifted, albeit on a long time-scale.

Note that both coal and diamonds are actually time-shifted carbon usage, on the scale of millions of years.

[tomsyouruncle]

> When you switched from burning lignin to solar, you reduced your carbon usage. However, what happened to the lignin that you stopped using?

In my scenario, CarbonCruncher bought the lignin I stopped using and made a road out of it. Crucially, in doing so they claim to have a negative carbon impact because they'd trapped that carbon in the ground. But I already claimed that impact when I stopped buying and burning it myself and switched to a zero-emission energy source.

So my (genuine) question remains: we can't _both_ claim the benefit, so who's right?

[anamax]

What's the relevance of "claim"?

Thousands of people get "best grandma" coffee mugs each year. Logically, only one of them actually is, but who cares and why?

[ghostbust555]

This is exactly my point (the after 3 years if it decomposed you are just time shifting) which is why I asked how long the roads take to decompose and what they translate into. Sooner or later that lignon in the road will become C02. But is that in 10 years? 100? If its time shifting it only by 15 years or so then its NOT reducing the total carbon to the atmosphere, just temporarily storing it. No different than putting the lignin in a warehouse for 15 years before burning it. So to call that carbon negative is just... bad math at best.

[ghostbust555]

My problem is that a) the lignin will decay into C02 (what is the time frame on this? if its hundreds of years then maybe there is some merit here) but b) this implies that if a paper mill wanted to claim to be "carbon negative" they could simply build a warehouse and store lignin for a while before burning it. Furthermore, it implies that if I wanted to claim to be 1 million kgs carbon negative I can simply make a threat of starting a forest fire. If I then DON'T burn the forest I now can say I personally removed 1 million kgs of C02 from the atmosphere.

[haakonzen]

Yes - time and degradation is key. All evidence we have as of today suggests close to none degradation of the lignin, and if/when eventually some degradation happens (yet to happen on the roads we have from 14y back), sequestration downwards in the soil, from the deep stabilized road layer we have bound with lignin. This is a very important area for us to pioneer research on going forward to get completely right, thanks for all the comments here, it will help us sharpen our efforts.

[kroil]

Adding this one, we are spending a lot of time getting all the calculations on sequestrations right, here is some deeper information on this. https://carbonplan.org/research/ton-year-explainer

[haakonzen]

Great thread, thanks all for the passion for this important topic. Just to clarify; we go from 7-10kg CO2 positive for traditional methods, to 5 kg negative pr m2 in two steps; Step one is we reduce emissions from value chain; incl. transport, & extraction when our Crusher recycles the road, which takes us to just above 1kg pr m2 (massive savings already from the traditional method). The remaining ca -6 kg is the effect of lignin - turning the calculation towards negative - and here debated in the thread with different opinions.

[civilized]

Why is lignin burnt today?

[el_oni]

Its a complex highly aromatic (in the chemistry sense) large molecule that there is active research in trying to convert to useful chemical products.

However it's quite difficult to break its bonds in ways that yield useful compounds. And until there is a viable way of upcycling it, burning it for energy is what they do

[lvs]

Except the current use of the byproduct is not just flaring it off pointlessly as waste. The byproduct is being burned as a fuel, which in that usage is already (nearly) neutral. If an alternative fuel has to be used instead, that fuel is more than likely going to be natural gas or coal.

[testrun]

This is how we lose the war against global warming. The process here is simple: 1. Tree captures carbon 2. Carbon gets buried in a road.

Simple.

For warming we can use electricity generated by wind, solar, tides etc.

Do not move the goalposts.

[ghostbust555]

3. Carbon in lignon road is released as it decays over time.

[dymk]

Do you have a source that the binder is currently being used as a fuel source? I'm missing where that's implied by the OP.

[hansarne]

It's correct that lignin is used as a fuel, here's one source of it. ~98 is burnt. "currently most of the lignin produced from paper industry is burned as low-value fuel to generate electricity and heat (Luo and Abu-Omar, 2017) and only less than 2% is used for producing specialty chemicals ..." https://www.sciencedirect.com/science/article/abs/pii/S09266...

[civilized]

I wonder what makes it a low value fuel. If it has a lot of carbon per energy released, it may be better to bury it than burn it.