CHON World

By Ian Page – 2021.11.15 I forgot to add the negatives in my enthusiasm   1 ton of aluminum generates 3 tons of toxic red mud. Currently there are about 80 active Bayer plants of which approximately 30 are in China. In addition, there are at least another 50 closed sites, and the combined stockpile of bauxite residue at active and legacy sites is estimated at 3000 million tons. Since there are accidents dumping red mud into stream and rivers, and these are very expensive for the producers, they are trying to find ways to use red mud. Scandium can be extracted and interestingly its only main use is as an additive to aluminum, and various other metals such as iron and titanium can be extracted. In addition, the highly alkaline nature can be neutralized by pumping CO2 into it, which turns much of the sludge into non caustic carbonates and can be used as a cement additive. It sounds like a problem that is not insoluble, but might cost money. China and Russia as well as Alcoa are triall...

By Ian Page – 2021.11.15 I'm getting a little frustrated that every time I find what seems to be a critical resource for the future, China seems to own it!  There are a number of places where aluminum can replace steel or copper in large quantities (warships isn't one of them as the US proves regularly) e.g. HVDC long distance cables, and EV bodies, so I wanted to know where it was coming from. China is by far the largest producer of aluminum   The raw material for aluminum is alumina from one of several geological types, The most accessible for Europe is Guinea. China can easily access the other two large sources Australia and Vietnam, even though it has very limited actual reserves itself.   Aluminum is very highly recycled, and since the other main input to aluminum is energy (aluminum is referred to as solid energy because it takes so much), cheap energy is a key determinant of where it's made. Recycling involves much less energy and should thus be cheaper. Thus, one ...

By Ian Page - 2021.11.14 I've just been reading Elon Musk’s carbon capture X prize, but no one has suggested collecting autumn leaves and burying them deep underground in old mines. (After drying of course). Given the outcome of COP26, (2.4 Degrees warming not 1.5), we are going to need some serious CO2 direct air capture to suck the stuff out. Leaves that are collected in city streets are generally too polluted to use on the land, and so tend to be burnt, which generates some energy but puts the CO2 back in the air (as well as some of the pollution) If they were instead buried/sequestered they would effectively achieve direct air capture, the only additional cost is finding a suitable hole to put them in and seal them up. (They must be dried before burning anyway) I've no idea what contribution this would make, or if there are enough easy access holes, but it struck me as a plausible concept. (If wet they would generate methane over time, so an alternative is to put them in ci...

By Ian Page – 2021.11.12 https://www.pv-magazine.com/2021/11/11/novel-way-to-calculate-levelized-cost-of-hydrogen-generated-by-offgrid-pv/ A big issue is the levelized cost of hydrogen electrolysis from solar. Typically, I have seen figures of $4/kg. This paper finds that the energy produced by a PV array is higher than usually estimated (using actual data, which helps!) and finds a better estimation method for the LCOH. The journalist then gets a bit confusing. Grey hydrogen costs $1.34-2.4. They calculate $2.36 for green hydrogen in Australia (PV alkaline electrolyser, grid connected but PV goes directly to the electrolyser). Then it's not clear whether they have used a 100% use function for the electrolyser (50KW electrolyser with 100Kw PV array and battery) whereas elsewhere they refer to not having allowed for battery costs. There is obviously a range of costs based from 100% utilization of the electrolysis with battery support, to 50% utilization with no battery support and a...