Projects within the olivine option that require no carbon credits for their realization
In recent discussions with colleagues, several times the opinion was voiced that projects in which the weathering of olivine or its hydrated equivalent serpentine were used could never become a business case without associated carbon credits. This is incorrect, and we present examples where the use of olivine weathering is already practiced, and funded directly by the users. we will also show some cases where it is obvious that their realization does not require the use of carbon credits to become profitable.
List of projects already operational, without any contribution from carbon credits:
- Potting soil enriched with olivine. The first 100.000 bags are on sale in garden centers in the Netherlands.
- Olivine integrated in roofs. Tens of thousands of m2 of roof have already been covered by olivine in the Netherlands, and a number of companies (including now the first in Germany and Belgium) are actively engaged in this business.
- Sand filters in urban waste treatment plants are replaced by olivine sandfilters, and the first full scale system is running.
- A large golf course in the Netherlands is going to use a mixture of 80% sand/20% olivine sand. Members are pleased, because this way they know that they will contribute to the removal of CO2 from the atmosphere.
- ProRail, the company responsible for the care and maintenance of the Dutch Railways is carrying out a pilot study to cover the inspection paths along the railroad with olivine.
- Some projects seem bizarre, but are still a workable business case. This holds certainly for a German textile company that produces synthetic fibres for clothing. They have incorporated tiny grains of serpentine in these fibres, and have started to make textile with it. Our tests have shown that during the washing of these clothes, it adds alkalinity to the water, which in turn will react with CO2, capturing it as bicarbonate in solution.
Future projects that will be financially self-supporting
Greening the fires
When serpentine slurries are used instead of water, fires can be extinguished considerably quicker. Serpentine is an abundantly available hydration product of olivine. It can be considered as a clay mineral. It is well-known, of course, that making bricks from clay is an energy-intensive process, and the required energy is a major cost factor in the process. When a warehouse, an industrial plant or a forest are on fire, this can be seen as a situation where there is too much heat in the wrong place. If one can remove this heat, it would help to extinguish the fire. The calcining of serpentine (similar to brickmaking) is such a process that takes a lot of energy. By spraying a fire with a slurry of serpentine instead of only water, it extracts heat from the fire that can be extinguished much more rapidly. A recent test at the test site of the Dutch fire brigades with serpentine slurries obtained from Spanish and Austrian serpentine deposits has demonstrated this clearly. What also helped was the fact that the calcined serpentine forms a kind of cake on the burning material, impeding the escape of burning gases. So, the calcining of serpentine can assist in fire fighting. The product is a kind of amorphous olivine that reacts very fast with CO2 and water, thereby sustainably storing CO2. It is clear that the use of serpentine slurries in fire fighting, once it becomes established as the cheapest way to extinguish large fires will not require additional funding from carbon credits. In our opinion it can be used at very large scale in forest fires, capturing CO2 and adding magnesium to the soil.
Many large office buildings and schools suffer from the sick-building syndrome. This is, certainly in part, caused by the rise in CO2 levels of the inside atmosphere in crowded buildings. At the end of the working day, CO2 levels may have gone up to 1500 or 1600 ppm, making people drowsy, and they lose their concentration and productivity. Evidently, in view of energy saving, doors and windows should remain closed. One can counteract the build-up of high CO2 levels by applying an indoor air circulation system, whereby the air is bubbled through a CATO (Clean Air Through Olivine) filter. This filter, which may be installed in the basement of the building could conceivably take the shape of a long V-shaped trough filled with an olivine slurry. The air passes through a tube mounted in the bottom, with many tiny perforations. By the reaction of the rising air bubbles with the slurry, their CO2 is converted to bicarbonate in solution. At the same time pollen and other allergenic dust particles will be trapped. In order to prevent a build-up of magnesium, bicarbonate and silica, which may cause scaling, CATO filters should be operated in connection with a larger external reservoir, like a small ornamental lake. The silica added to the lake will promote the growth of diatoms, an excellent fish food. The increased biomass is another way of catching CO2.
The schools and offices can claim that they compensate the CO2 emissions of their own pupils and employees. In areas where there are several large schools or office buildings, the use of the lake can be shared by a number of different CATO filters.
Diatoms and biofuel
Land based biofuel crops (oil palms, soja, corn, and wheat) occupy large land areas, which are no longer available for world food production. They also use up a large part of scarce irrigation water, as well as scarce fertilizers like potassium and phosphate. Those problems can be avoided by switching to large-scale farming of suitable marine organisms, notably algae. The most promising are diatoms. Diatoms grow fast and constitute 20 to 25% of the oceanic biomass. This might even be more but for the fact that they are often silica-limited. One could overcome this limitation by the following set-up for diatom farming. A stretch of beach should be covered with olivine, between the ebb line and the high tide line. The area in front of this beach should be dammed, and this enclosure will serve as a diatom farm. The dam should have one or several U-shaped tubes that connect the open sea with the artificial lagoon, permitting the tides to flow in and out of the lagoon. At high tide the beach is completely wetted. At low tide the beach is drained, and the water that has reacted for a number of hours with the olivine flows into the lagoon, carrying the dissolved silica with it. It gives diatoms a competitive edge over organisms that do not require silica for their growth. It must be prevented that the diatoms are washed out to sea. This can be achieved by closing the U tubes on the lagoon side with a perforated metal cover, which serves as a support for a plankton net that retains the diatoms, which makes their harvest possible.
Making oil out of algae is already a known process. Several industrial sectors have already shown interest (among which an oil company). The Port of Rotterdam is willing to support the idea, and make a section of coast along the new industrial island available as a test site.
Adding fine-grained olivine to biodigesters
Another way to replace fossil fuels by CO2 neutral fuels is biogas. During anaerobic digestion of agricultural or animal waste, the gas that is produced consists on average of 2/3 methane and 1/3 CO2, with minor concentrations of H2S. By adding olivine to the digesters, it turns out that the gas becomes relatively richer in methane, because part of the CO2 is transferred as bicarbonate to the liquid phase. A second effect is that the smell is considerably reduced, because the Fe-silicate part of the olivine reacts with H2S to form insoluble iron sulphides. It was also found that the absolute amount of methane was increased (due to 6 Fe2SiO4 +CO2 + 14 H2O à 4 Fe3O4 + CH4 + 6 H4SiO4). This is a very cheap and attractive way to increase the production of a high quality biogas, while taking away some of the unpleasant environmental consequences of biodigesters. The purification effect can be increased by carrying out the digestion process under a modest overpressure. Theoretically an increase of the gas pressure to 10 bars will move 90% of the CO2 of the gas into the liquid digestate. Another advantage is that the enzymes of the yeast require some nickel, of which traces can be provided by the dissolving olivine grains.
We will not describe in any detail projects to use olivine sand in the banks of highways, use it as olivine grit on icy roads, use it when a sand suppletion has to be made to repair beaches damaged by erosion, the use of olivine to make artificial reefs, e.g. for the culture of oysters and many others, although such projects are now being studied by the Dutch Water Authority and by several large construction companies.