SUMMARY
Most of the fossil fuels are currently used for transportation, to generate electricity or used for heating purposes. Mainly due to the increasing world population and the economic development of countries, the energy demand will increase rapidly. If society will still use fossil fuels in the future to supply this demand, we are going to be faced with major fossil fuel shortfalls and increasing CO2 emissions. The Icelandic company Carbon Recycling International (CRI) think they have the answer for both major global problems and developed a way to recycle CO2 into biofuel, which can act as a replacement for fossil fuels. CRI only uses geothermal power, water and CO2 to convert this in methanol. They claim that, on a short term, this technique can replace fossil fuels and they think it is possible to decrease CO2 emissions to pre-industrial levels. But is it technically possible to recycle CO2 and are the claims of CRI correct?
An important fact is that also hydrogen is required to convert CO2 to methanol. Converting CO2 into methanol is not a new technique and already developed by BASF in 1905 when CO2 and hydrogen were obtained from fermentation gases. What is new is the way of producing hydrogen with the electrolysis of water and capturing CO2 by only using geothermal power. Iceland has a large potential of geothermal and hydropower. Furthermore, CO2 can efficiently be captured from geothermal power plants. Both reasons, give CRI the opportunity to produce large amounts of renewable methanol.
Only electricity is required to convert CO2 to methanol. Unfortunately, the total energy efficiency from electricity to methanol is relatively low with 42 up to 55%. This depends on where the process is located, how CO2 is captured and how the electricity is generated (geothermal, solar, wind et cetera). In this process, CO2 is basically a temporary feedstock because, with the combustion of methanol itself, captured CO2 will be released again. Therefore, no CO2 will be recycled by CRI. The situation is even worse, it will cost CO2 when new geothermal power plants are used to produce renewable methanol.
The only realistic option to recycle CO2 is when it is captured from fossil fuel power plants or from industry. In this situation, captured CO2 is converted to methanol and with the use of this methanol, the same amount of CO2 will be released again. The best option that CRI can achieve is to create a closed-loop of CO2 when it is captured from atmospheric air. This means, when it is applied on a large scale, it can actually stabilize CO2 level. However, it is untrue that CO2 levels could decrease to pre-industrial levels. Also too few information is available about the actual energy consumption of a large scale implementation of this kind of methanol production.
The total potential of Iceland is not large. Using the maximum available geothermal power and CO2, the potential is limited up to about 350 million litres of methanol a year. This is large enough to supply the Icelandic demand of methanol when this is used as a replacement for conventional gasoline in passenger cars. Exporting this amount to the Netherlands would not even supply 3% of all gasoline cars in the Netherlands. The potential could be five times larger when also potential hydropower is used and extra CO2 is captured from the industry. In this case, CO2 will be recycled but the potential is still relatively small. Furthermore, the production costs will be even higher than the current estimated production price of 600-1200 euro/ton of methanol in combination with old geothermal power or hydropower plants. To compete with the current fossil fuel-based methanol market prices of 300 euro/ton, the production of renewable methanol has not to be taxed or the production has to be subsidised.
When this methanol process is applied on a global scale, the maximum potential of geothermal power could almost replace current demand of methanol. This would actually save about 30 Mton of CO2 a year, which is about 0.1% of all annual global CO2 emissions. Unfortunately, the second claim of CRI is also not true. The use of only the available geothermal power and CO2 cannot replace the global demand for fossil fuels.
A positive fact about this technique is that it can store electricity and can therefore function as a potential energy buffer. If a country tries to install unpredictable and variable renewable energy sources such as wind and solar, at some moments, more electricity can be generated than is actually needed. This oversupply can be used to produce methanol to buffer energy. The most ambitious plan of the Dutch government is to implement 6 GWe offshore wind, 4 GWe onshore wind and 4 GWe of solar PVs by the year 2030. When this scenario is simulated in PowerPlan (a medium term program that simulate the electricity supply and demand of a country), the result is that the oversupply of electricity in the Netherlands is too small. Besides renewables, the Netherlands also invests in more flexible fossil fuel power plants. These will be used to minimize the occurrence of a electricity oversupply. Therefore, methanol production in the Netherlands by the year 2030 cannot advantageously be used as a potential energy buffer. Perhaps it can be used in countries such as Germany that are trying to invest more in solar and wind power and are therefore faced with larger electricity oversupplies than the Netherlands.
