In our previous Carbon dioxide (CO2) capture and sequestration post we promised a post about microalgae storing carbon dioxide and here it comes! We already agree on the need to reduce carbon dioxide emissions in order to mitigate climate change and microalgae capturing CO2 with their photosynthesis can be our ally because of the following reasons:
- They grow faster than plants and produce two to tenfold more biomass per unit land area than the best terrestrial systems
- Do not require fertile land or useful water
- Can use direct flue gases to obtain the carbon they need
- They can grow with little sun and sometimes they don’t even need light
But we can’t start growing microalgae all around greenhouse emissions sources in order to reduce CO2 without considering what to do with all the biomass which will be produced. We need to convert the biomass into biofuels or products which can be used in large-scale sectors (energy supply or commodities). Otherwise the fixed carbon managed will be again released to the atmosphere on its decomposition process and the mitigation effect of the use of microalgae won’t be able to be considered as a sequestration method.
Besides, there is the need to develop the appropriate technology to integrate the carbon dioxide from flue gases with the microalgae, since the flue gases can contain other undesirable compounds which need to be separated and its high temperature needs to be lowered before contacting the microalgae. Finally there is the need to pump gases to the bioreactors or place where the microalgae are growing which can result in an extra energy consumption.
As you can see, it is not a straight forward cost-effective process. Even though microalgae use for carbon capture has been studied since 1960, they haven’t become a potentially competitive option until recently. The raise of its interest have got the origin on the increase of the petroleum prices and the climate change challenge, especially with the boost of biofuels as contributors for a sustainable energy mix and the limited arable land available to obtain the required biomass.
Several projects are being developed worldwide investigating the use of microalgae:
- Norway has funded a construction of a 300 square-meter algae production test facility at the Technology Centre Mongstad (TCM) to feed fish due to the raise of aquaculture and the need to find alternative and sustainable marine raw materials.
- Sapphire EnergyTM based in San Diego is the first company to produce a renewable source of crude oil on a continuous basis from algae biomass and to operate the largest-algae-to-energy facility in the world.
- In Japan, Tsukuba University is leading several studies on the use of microalgae in order to create a strong industry on algae including energy, chemicals, foods and cosmetics production.
Although the costs are still high and the technology hasn’t reached a commercial scale, several efforts are being put on it and the forecast is to reach a sustainable and economically feasible use of microalgae within the next 10 to 15 years.
Microalgae are not the only innovative approach in order to capture and decrease the level of CO2 on the atmosphere. We want to present some startups working to develop breakthrough technologies:
- Novomer: it commercializes a catalyst (a substance that causes or accelerates a certain chemical reaction) which transforms carbon dioxide to low cost polymers with different applications.
- DyeCoo: designs, develops and delivers CO2 dyeing solutions which avoiding the use of the required water and chemicals in conventional processes while using and abundant resource.
- Newlight Technologies: the company has invented and commercialized a carbon capture technology that combines air with methane-based greenhouse gas emissions to produce a plastic material called AirCarbon™: a carbon-negative material that can match the performance of oil-based plastics and out-compete on price.
We hope to continue hearing about the use of microalgae and other innovative ideas to use CO2 to help in the climate change challenge! Share with us your findings and knowledge if you know about another amazing projects, startups or ideas!