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Is Olivine the solution against Climate Change and Ocean Acidification?

CO2, Climate Change, Olivine, Schuiling

Olaf Schuiling: ” Milled olivine is a sustainable solution reducing CO2 and save the Climate”

The world is desperately looking for safe and cost-effective solutions to counteract climate change by reducing the CO2 levels of the atmosphere.

Olaf Schuiling, professor Geo Engineering at the University Utrecht (Netherlands) proposes Olivine.

Olivine isn’t new. It is as old as the world, namely to use olivine or similar rocks not in a technology, but in the way it works in nature.

Does this professor has the solution for the increasing CO2 and the effects on Climate Change?

Olivine (Mg2SiO4) is the most common mineral on earth. Since the sixties professor Schuiling investigated the reaction between dissolved CO2 and Olivine. In addition, heat is released, and the CO2 binds to the innocent bicarbonate, which may be later precipitates as lime.

Schuiling: “It is one of the easiest ways to capture CO2 from the air. It is a safe, natural and inexpensive process.”

Buildings and schools

The absorption of CO2 is optimal when the Olivine is crushed to sand. Scattering of the Olivine is possible in streets, green strips near roads and industrial sites, parks, gardens, beaches, and in the sandpits of schools. Olive converts CO2 into calcium and so reduces CO2 in the air.

“If the Olive grid is spread onto land and shallow water in the wet tropics, in a year about 20 percent of the CO2 will be weathered. When we repeat the proces every year with 7 cubic kilometers of rock, we will compensate the whole human CO2 emissions.”

Costs

The costs to dig and pulverize Olivine in tropical countries are about $ 6.5 per ton. If you assume that for the transportation and spreading another $ 6.5 per ton are needed, the costs are 13 USD per ton of olivine: about 10 USD per ton CO2.

Sediments

Weathering of calcium and / or magnesium silicate rock has kept the CO2 content of the atmosphere within reasonable bounds throughout geological history. Weathering is the neutralization of an acid (usually carbonic acid) by rocks, turning CO2 into the innocuous bicarbonate ion in solution.

These bicarbonate solutions are carried by rivers to the sea, where they are ultimately deposited as limestones and dolomites.

These carbonate sediments form the ultimate sink for CO2. They contain 1,500 times more CO2 than the amounts of CO2 in biomass, atmosphere and dissolved CO2 in the oceans combined.

Reduce emissions

Two broad families of geo-engineering solutions have been proposed:

  1. First is to alter the Earth’s thermal balance by reflecting more incident solar radiation out to space.
  2. Second is the direct removal of CO2 from the atmosphere.

Both approaches have their place but note that the first category does not address the serious issue of ocean acidification (report). Accordingly it would be unwise to rely on enhanced reflectivity alone. Of the second category of geo engineering approaches, the most logical is to increase the rate of weathering since this is a natural process whose enhancement may be considered “benign in principle”.

This can be done by mining abundantly available and easily weatherable rocks, milling them and spreading the grains over the surface of the land or in shallow seas.

The olivine option is not so much a ‘technology’ in the classical sense, but more a general concept that can be applied in many sectors of society.

Projects based on enhanced weathering of olivine and related minerals have been formulated for agriculture, forestry, roads and biking paths, buildings, coastal defense, firefighting, playgrounds, suppression of poisonous dinoflagellate and cyanobacteria blooms, diatom farms for biodiesel production, mining, mineral waters, olivine as a green fuel, olivine in environmental applications, natural emissions of CO2 for carbon capture and miscellaneous.

Silica

The solutions that are produced by the digestion of olivine grains are rich in silica, which is a limiting nutrient for diatoms. When silica becomes available in larger quantities, the diatom population will increase, providing food for fishes and birds further up the food chain.

Limited speed

Colleagues point out correctly that, as in nature, the rates and speed of the reaction of minerals like olivine can vary greatly in different situations found in the natural world.

More work needs to be done to understand these processes.

However, don’t mistake that for a reason for inaction, whilst we may be unsure of the absolute potential, we are sure that the potential is there.

And, as in nature, with such a wide range of applications for weathering minerals in our human activities, virtually everybody can participate in their own field and help move these techniques forward in the fight to counteract climate change and ocean acidification.

Combating climate change and building a sustainable future, there are a lot of interesting and potentially very helpful actions and developments to be embraced. And Olivine is one of them.

Link to the EU- report The Costs of CO2 Capture, Transport and Storage

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2 Responses to Is Olivine the solution against Climate Change and Ocean Acidification?

  1. Gene Fuss says:

    Manmade global CO2 emissions reached a record high of 35.6 billion metric tons in 2012. At 2/3 ton of CO2 removed per ton of olivine, that means 53 billion tons of olivine would be need to be mined per year to absorb the man made CO2 emissions
    Total global mining output is 17 billion metric tons per year as of 2015.
    The olivine would also need to be milled to efficiently capture the CO2.

    Formation of carbonates is by diffusion of CO2 through existing layer of carbonate mineral to reach unreacted olivine oxide interface. The reaction starts quickly, but slows rapidly as the carbonate surface layer builds. Only about half of the olivine would be converted to carbonate because of the diffusion-limited process, unless the olivine was milled to less than 100 nanometer (0.1 micron) size.
    So over 100 billion metric tons of olivine would need to be mined and milled annually to absorb those 35.6 billion metric tons of manmade produced CO2.

    Olivine is a volcanic magma-formed mineral. You will find it mostly where volcanoes are found. It is concentrated in those zones only. In the U.S. that is on the east and west coasts. Worldwide, it is in the zone of the tectonic plate edges.
    upload.wikimedia.org/wikipedia/commons/thumb/b/b0/Map_plate_tectonics_world.gif/350px-Map_plate_tectonics_world.gif
    And the rainfall would ‘weather’ the formed carbonate dust, washing it into the rivers and streams into lakes and the ocean. The oceans absorb 90 billion metric tons CO2 per year, release 88 billion metric tons per year, for a net gain of 2 billion metric tons per year. This is only 2/35.6 of total global CO2 emissions, combined manmade and natural. This is 5.6% of the MANMADE CO2 emissions. A drop in the bucket.

    So while possible in theory, the logistics and energy requirements, plus the net capacity of the primary final sink of CO2, the oceans, make the scheme impractical. You’d be better off dumping the milled olivine directly into the ocean, but that would create an oceanic environmental problem. Both in the form of high turbidity (cloudiness) of the water where dumped, plus coating the ocean bottom with the olivine dust as sediment, killing the ocean bottom aquatic species for miles around.

  2. Pol Knops says:

    1st there is no need to compensate ALL of the global CO2 emissions with Olivine. So reducing the amount.
    2nd the proces can run for a few years. So reducing the milling requirements
    3rd Indeed the application needs to tested. Currently is Olivine in the Netherlands used by a SME Greensand for civil applications. So places were you would use anyway a sand/pebble material. I.e. to replace granite at a railway inspection path.
    We need to CO2 reduce, re-use and remove.

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