Black mountains sit in Venezuela: 15–30 million t of petroleum coke. There is no use for it there, and export doesn’t pay: ports and logistics are costly, and US sanctions hinder sales. New coke is added every day. What do we do with it?
The mountains grew for years
After the 2009 fire at the Jose port, exports stopped and coke was piled on open ground. Black dunes rose next to villages, and residents complain about the dust. The state oil company has tried to cut the stocks for years, with little progress.
This is not waste. It is carbon with sulfur, vanadium and nickel stuck in it. They are what make coke useless: burning it is out because of the sulfur, and the metals get in the way of graphitization. So we start with cleaning.
Step 1: pull out the sulfur and the metals
Vanadium and nickel are removed by leaching, so no carbon is burned to make ash. ARBOK separates the solutions into fractions, as in ARBOK-Vanadium: a vanadium concentrate and a nickel concentrate. That is the first product. Vanadium is a critical metal: China produces over 50% of the world’s supply, the US depends on imports, and flow vanadium batteries for long-duration storage grow about 20% a year. The sulfur we pull out is a product too: it goes into sulfuric acid and fertilizer. Clean carbon is left.
Step 2: fuel briquettes
Coke fines are pressed with a binder into briquettes; the technology is known, and the binder is up to 15% of the mass. A briquette free of sulfur and metals goes to an industrial user as heat. Coke has little volatile matter and ignites poorly, which is why cement makers grind it fine. TEGA may improve ignition and burnout, and R&D will test that.
Step 3: graphite
Classically, graphite can be made from fuel coke with an iron catalyst below 1600 °C. From cleaned coke it is easier and cleaner. TEGA is added to the graphitized coke, giving a conductive composite for electrodes and batteries. TEGA’s thermal conductivity is 100–470 W/(m·K), so the composite also sheds heat. TEGA is pure carbon, with no silicon or rare earths, and it is recyclable: ground and re-sintered in a furnace.
Three products from one mountain
Briquettes bring volume, graphite and the composite bring price, vanadium and nickel bring metal. The mountain stops growing when processing outpaces the new coke. Vanadium and nickel stay where the coke lies; briquettes go to local kilns.
R&D is needed: three series on real coke from the Orinoco piles and the Jose port. Cleaning the coke of sulfur and metals. Briquettes with and without TEGA. Graphitizing cleaned coke with TEGA. In each series we measure residual sulfur and metals, briquette strength and composite conductivity. ARBOK is ready to develop the technology and the technological complex for a specific plant.