BY JOSE PALU-AY DACUDAO
SOLUTION: Use charcoal as the carbon source instead of coal.
The essential chemical process in all of the above reduction of the metal oxide (MeO) is: 2 MeO (metal oxide) + C (elemental carbon) → 2 Me (elemental metal) + CO2 (carbon dioxide)
If we use coal, whose carbon was fixed from the atmosphere millions of years ago by now fossilized ancient plants, we are outputting a net amount of carbon dioxide into the atmosphere.
On the other hand, if we use charcoal, whose coal was fixed from the atmosphere less than a few decades ago by today’s plants, then we are essentially taking CO2 from the atmosphere and releasing it back again with no net input or output in a geological instant.
Equation for photosynthesis:
6 CO2 (carbon dioxide taken from the atmosphere in a geological instant of a few decades or less) + 6 H2O (water) → C6H12O6 (organic substance) + 6 O2 (oxygen)
Equation for charring/ carbonization/ pyrolysis (charcoal production): C6H12O6 (organic substance) → 6 H2O (water) + 6 C (charcoal elemental carbon)
The equation for the chemical reduction of the metal oxide is essentially: 2 MeO (metal oxide) + C (charcoal elemental carbon) → 2 Me (elemental metal) + CO2 (carbon dioxide released back to the atmosphere in a geological instant in the smelting procedure)
Thus, the over-all process of smelting metal oxides, upon cancelling the appropriate terms on either side of the equations, is: 2 MeO (metal oxide) → 2 Me (elemental metal – iron, aluminum, magnesium, chromium, and so on) + O2 (oxygen released to the atmosphere in a geological instant)
The carbon becomes a kind of spectator in the summarized chemical process, the amount taken and emitted into the atmosphere being the same. And no one will complain of oxygen being a ‘waste product’.
Therefore, in reducing carbon dioxide emissions in metal oxide smelters in general, a simple solution would be to use charcoal instead of coal.
Has this been done already? As mentioned before, yes, in Brazil. Its huge iron industry relies on charcoal for fuel and smelting. It just so happens that Brazil lacks substantial coal deposits, but can grow millions of hectares of commercial eucalyptus trees, thanks to the fact that Brazil is located in the very productive tropical rainforest zone. Lots of rain allow the fast growth of commercial trees that can be used to make charcoal.
Can this be done in the Philippines, as we are also in the very productive tropical rainforest zone? I believe that it can be done in Mindanao. The Mindanao wood industry is nowadays based on the falcata tree (Falcataria falcata). Originally imported from Maluku Indonesia, it has been grown commercially in Mindanao since the 1990s. Falcata is a member of family Fabaceae, the legume family of plants famed for their ability to fix nitrogen directly from the atmosphere. This is the reason why legumes are one of the favorites plants used in crop rotation; as they add to the nitrogen in the soil. This means that falcata trees can grow fast even in nitrogen-poor soils without any fertilizer. Mindanao also grows vast groves of coconut trees, which has helped the Philippines become one of the world’s top producer of coconuts and coconut oil. The falcata wood industry and the coconut industry in Mindanao are prodigious, and they produce immense quantities of waste wood chips and coconut husks that may be turned into charcoal. We can import the necessary giant iron retorts from Brazil, in whose interiors woody products are cheaply charred into massive quantities of charcoal. Local farmers would also gain additional income from growing more falcata and coconut trees for charcoal production. The charcoal can be used in the iron industry in Mindanao. Iron ore smellers using charcoal as fuel and reducing agent can be set up in the Surigao provinces, which have substantial iron ore deposits. This would establish an indigenous iron industry, independent of foreign coal imports and smelters./PN
