Comment by DavidPeiffer | Hacker News Reader

Comment by DavidPeiffer | Hacker News Reader

I'm not certain the differences, but there's been a similar effort as a joint venture between Alcoa, Rio Tinto, and Apple to clean up the aluminum smelting process. [1]

The aluminum industry is notorious for having incredibly high energy requirements, and being price sensitive to changes in energy contracts. The economics behind smelters are challenging and at an unimaginable scale. Having an electricity interruption of more than a handful of hours can cause the aluminum in-process to solidify, causing tens of millions of dollars in damage to the smelter and requiring months to fix. This paper [2] describes a framework for making decisions to enter/exit a market based on variability of inputs, investment required to exit/enter, etc. While the example in the paper is focused around renewable energy, it can be applied to other types of facilities. We covered this paper for about 2 weeks during undergrad, which at the time was painful, but it was one of the most interesting papers and concepts I've read.

A great video outlining the refining process is available in [3]. Having worked there, I promise the safety at Alcoa is now far superior to what's shown in the video. Paul O'Neill hadn't become CEO yet [4].

[1] https://www.apple.com/newsroom/2018/05/apple-paves-the-way-f...

[2] https://www.imse.iastate.edu/wp-content/blogs.dir/16/files/2...

[3] https://www.youtube.com/watch?v=J5wPJp-hasU

[4] https://www.forbes.com/sites/roddwagner/2019/01/22/have-we-l...

Alcoa and other big aluminum producers have been interested in eliminating the carbon anodes from aluminum smelting for decades, well before global warming concerns rose to the forefront. It is a very difficult problem to make inert anodes efficient and stable enough for long term industrial use. I hope that these recent advancements are enough to start replacing carbon anodes in commercial plants. Some of the non-CO2 reasons to eliminate carbon anodes:

- Carbon anodes oxidize while they are in use. Their shape and size changes over time as they erode, and the pot has to be shut down to replace ones that are too worn.

- The oxidation of carbon anodes contributes part of the energy needed to transform aluminum oxide into metallic aluminum, but their embedded energy content is much more expensive than the electricity smelters use. The combined materials + electricity cost to produce a ton of aluminum would be lower if efficient, stable inert anodes could be developed.

- The oxidation of carbon anodes, ideally, produces pure carbon dioxide. But in actual operating conditions the anode oxidation also produces toxic gases like carbonyl fluoride and carbon monoxide as minor byproducts. Safety systems and processes to prevent toxic gas exposure of workers make it more expensive to build and operate smelters than if the byproduct gas were oxygen.

> Having an electricity interruption of more than a handful of hours can cause the aluminum in-process to solidify, causing tens of millions of dollars in damage to the smelter and requiring months to fix.

-When touring an aluminum melting plant in Norway (which exists only because of cheap, reliable hydropower - the bauxite is shipped in from Australia, mostly), I was told the last-ditch measure to avoid such a situation was a metric shitload of gravity-fed kerosene burners with redundant fuel supplies located at the critical (that is, hard and expensive to replace) parts of the line.

They really, really didn't want to look at a solidified production line.

I haven't been through a smelter, but would love the opportunity to tour one sometime. Were you on a public tour, or was it through a business dealing?

Business dealing of sorts. My grandfather was an engineer with the utility company and brought me along once, figuring I'd find it interesting. He was right.

I think its interesting in the Northwest, Huge Dams were built on the Columbia River to power Hanford (and the Manhattan Project) and the large glut of power after it was scaled back made it cheap to move Aluminum Smelters there. (and to Send 3GW of Super High Voltage DC power to LA from near Portland) Then, in the 90's, when power got more expensive (and more environmental rules) they moved them all overseas. That left a huge glut of Power in the area. So now, Facebook, Microsoft, AWS, Google All built their datacenters there.

> So now, Facebook, Microsoft, AWS, Google All built their datacenters there.

Along with piles of bitcoin miners at least for a while.

Was Hanford there for power or for cooling water (and general remoteness so people didn't die in an accident)? Can't remember but I worked at PNNL for a few years.

Still lots of aluminum smelting with hydropower in Canada.

Producing Aluminum requires so much power I've heard it refered to as solidified electricity.

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