ASU researchers suggest hydrogen use could significantly reduce emissions from copper mining
30 July 2024
A team at Arizona State University (ASU) has estimated the future amount of copper needed for clean energy transition (CET)-related technologies, focusing on the US market and the leading role of Arizona (AZ) in copper mining. Particularly, they evaluated hydrogen’s potential to displace diesel in haulage; for use in high-grade heat generation in smelting and fire-refining (anode) furnaces; and as a chemical feedstock in anode furnaces, by conducting a techno-economic assessment for replacing fossil fuels with clean hydrogen.
An open-access paper is published in the RSC journal Energy & Environmental Science.
The analysis shows a likely sizeable increase in future copper demand just for clean energy technologies by a maximum factor of 4.6 by 2035 and by a factor of 7.0 by 2050.
The researchers also found that there is an economic opportunity to replace diesel with clean hydrogen at the current hydrogen production costs with the help of production tax credits (PTC) for clean hydrogen in the US Inflation Reduction Act (IRA) adopted in August 2022.
Additionally, they show that carbon taxation is not an effective measure for copper mining to switch from fossil fuels to hydrogen.
Breakdown of CO2-eq emissions from inputs used in AF, kg CO2-eq/t Cu. The plot’s legend refers to the source of emissions, either from the production and reaction of reductant or from the production and combustion of the preheat input. Excludes losses of heat through the walls of a furnace. Kukula et al.
When scaling these results to encompass the total copper mining production output in the US, the estimated annual H2 demand to be approximately ~3 Mt H2/y. This demand primarily supports three applications: fuel for heavy mining trucks, a heat source for flash smelting furnaces, and both a heat and reductant source for anode furnaces.
From the emissions standpoint, if discrete hauling completely transitions from diesel to clean hydrogen, it could alleviate up to 70% of the total GHG emissions intensity of copper. If implemented only in one AF as a source of heat and a feedstock, hydrogen could remove ~4% of the total emissions intensity of copper production.
The presented analysis also shows that produced hydrogen with an emissions factor lower than 6.6 kg CO2-eq/kg H2 leads to lower emissions compared to when NG is used in copper mining. Reaching a 6.6 kg CO2- eq/kg H2 emission factor is possible when 100% renewable electricity supplies electrolysis or steam-methane reforming complements with carbon capture with a capture rate higher than 50% or when steam-methane reforming has nearly zero upstream methane leaking.
Besides discussed hydrogen production routes (SMR, SMR+CCS, and electrolysis), there are other ways of hydrogen production that may be interesting to analyze within copper production application. Biomass/waste conversion, thermochemical and photoelectrochemical hydrogen production are attractive production routes to consider. The major limitation to a reliable assessment is the low maturity levels of such technologies. Copper mining heavily relies on FF in different forms, which directly contributes to the lifecycle GHG emissions and increases the carbon footprint of clean energy technologies. Reaching carbon neutrality across different economic activities will require a significant decrease in GHG emissions of integral components, and copper is one of the most essential elements for growing economies.
—Kukula et al.
Resources
Iuliia Kukula Ivan Ermanoski and Ellen B Stechel (2024) “Clean Hydrogen Potential for Carbon-Neutral Copper Mining” Energy & Environmental Science doi: 10.1039/D4EE02823F
' Additionally, they show that carbon taxation is not an effective measure for copper mining to switch from fossil fuels to hydrogen.'
Since the rationale for this is restricted access, I am less than wholly persuaded, other than to note that most of us are adverse to paying more tax!
Posted by: Davemart | 30 July 2024 at 03:10 AM
As long as other taxes (such as on payrolls) are reduced when the carbon tax is implemented, we will not pay more in taxes. The idea is to tax what we want to reduce and let the market decide the most economical way to do it.
If '...they show that carbon taxation is not an effective measure for copper mining to switch from fossil fuels to hydrogen', then they are proposing a way to make us all poorer.
Posted by: Steve Reynolds | 30 July 2024 at 06:17 AM
Steve said:
' As long as other taxes (such as on payrolls) are reduced when the carbon tax is implemented, we will not pay more in taxes. '
Overall, absolutely. And real savings would be made by not producing so many nasties.
But industries fight their corner, and if, say, CO2 emissions are taxed for copper production, then that reduces demand, as production is often fungible against aluminum production, just not using so much power, and whatever.
So the interested parties are unlikely to be fans of increased taxation no matter how beneficial it might be from a wider perspective.
Posted by: Davemart | 30 July 2024 at 10:00 AM
The reason why carbon pricing wouldn't be effective in this case is because hydrogen is expensive. Not only are capital costs extremely high, but operating costs might not be any cheaper than diesel.
Obviously, that's from the mine operator's point of view. They don't have to pay for externalities, so they don't care if the air stinks (they live thousands of miles away), or if kids get cancer (their kids are skiing in the Alps). They won't have to pay to clean-up the toxic mess that they leave behind when the mine closes.
The solution is to charge mines for externalities, but that never happens. They have enough clout to kick-out any politician that would even think of trying such a stunt.
That's how we end-up footing the bill for hundreds of billions (in tax...) in order to save industry a thousandth of that amount.
Posted by: Bernard | 30 July 2024 at 10:50 AM
Hi Bernard:
The (unsupported by anything accessible) claim is that:
' Additionally, they show that carbon taxation is not an effective measure for copper mining to switch from fossil fuels to hydrogen'
High hydrogen prices might raise the level of tax you might need, but would not seem to show that a carbon tax would not work.
So as you say, mines and mining companies are great at avoiding paying for externalities, ie the true costs of production.
Fortesque is unusual in that, whether you agree with the specific measures they are trying to take or not, they are trying to decarbonise.
A combination of fossil fuel interests and Goverment in connivance with them is proving effective at stopping much of what they are trying though.
Posted by: Davemart | 30 July 2024 at 12:23 PM
While externalities should be included, high hydrogen prices indicate it requires a lot of resources to produce. Ignoring cost may result in even more unwanted externalities.
Posted by: Steve Reynolds | 30 July 2024 at 07:07 PM
Hi Steve
We have no idea if high hydrogen prices is the problem they have identified.
If you are looking at prices at the pump in California, those are anomolous, caused by small volumes for the negligible numbers of private customers, transporting it compressed in trucks and so on.
They are already considerably lower in Europe, and around $4.50kg in China at the pump.
As volumes build up for trucks, further falls are likely.
But in any case, providing hydrogen at major industrial locations such as copper refining facilities has far better, cheaper logistics due to high volume, low transport costs and so on.
The bottom line is that we have no idea why they imagine that carbon price taxation is an ineffective tool for reduction in copper production as they have not told us, just made a pronouncement.
I don't find that very convincing.
Posted by: Davemart | 31 July 2024 at 01:28 AM