As the global population increases, the appetite for energy increases too. According to World Energy Outlook 2015 and International Energy Agency (IEA), the primary energy consumption is predicted to increase by 37% between 2013 and 2035. Considering this increase in energy demand, there is an urgent need to find cleaner fuels that fulfill the growing energy demand and do not contribute to existing amounts of greenhouse gases. Biofuels from algae present an answer to this problem. Big agencies are exploring algae and other biological organisms for making biofuels that are sustainable, biodegradable and cost-competitive.
High-density fuels using algae
Algae biofuels do not contain sulfur, are biodegradable and are non-toxic which makes them an ideal fuel for the modern world’s needs. A number of algal strains have been found to produce fuel with energy densities comparable to conventional fuels, which is expected to open new avenues for the industry. Let’s now take a look at how biofuel is produced from algae and how much progress has been made in this field so far.
Types of Algae biofuels and the processes used in their manufacturing
There are mainly three types of biofuels – biodiesel, bioethanol, and biogas. Biodiesel is mixed with diesel, bioethanol is mixed with petrol, and biogas (methane) can be used to fuel specially adapted vehicles. In this section, we will discuss how biodiesel and bioethanol are produced using algae:
Microalgae contain oil within its cell. Different varieties of microalgae contain different amounts of oil. Once grown, the oil is extracted from the microalgae using chemical extraction methods or by squeezing oil out of algal cells. The oil obtained by these methods is plant oil, which is converted to biodiesel using chemical methods. The finished product can be used in its pure form or can be ordinary diesel.
Macroalgae is used for making bioethanol. Macroalgae, which contains high amounts of sugar is cut and treated to extract sugar. This sugar is then converted to glucose, after which yeast is added to the process. The yeast triggers a chemical reaction called “fermentation”, which produces ethanol and other by-products from glucose. The ethanol thus produced is separated from other components by a process known as distillation. The ethanol or bioethanol obtained is further filtered to remove water, so that it can be used as a fuel.
Problems faced during production and ways to overcome them
Algae grown on open ponds do not provide the best yields as they are not the most lipid-rich. Covering ponds with translucent membranes or using greenhouses overcomes this drawback. This approach also enables some control to be exercised for the best results. Modern scientists have gone a step further by adopting fabricated enclosures termed photo-bioreactors (PBRs), which maximize photosynthesis by slowly circulating the algae, along with carbon dioxide and nutrients. Many projects are underway:
- US firm Valcent Products, along with Canadian company Global Green Solutions is growing algae vertically in a large high-density greenhouse near El Paso, Texas. Growing algae vertically provides a lot more surface area to expose cells to sunlight, yielding better results.
- Another initiative using PBR systems that aims to utilize waste CO2 from power stations, cement production facilities etc is taken up by Massachusetts-based GreenFuel Technologies Corporation. This is being seen as a solution to mitigate CO2 production while producing clean fuel.
- Taking the technology a notch higher, the researchers at the University of Cambridge have recently developed algae-powered fuel cells, which are five times more efficient and cost-effective than existing plant and algal models.
Market size of algae biofuels in 2018
According to grand view research, the market size of biofuel derived from algae is expected to reach USD 5.96 billion in the year 2018. The growth of algae biofuels coupled with the mandates introduced by the U.S. government has opened new doors for the growth of algae-derived Biofuels. Not just this, the International Energy Agency predicts that biofuels will constitute 6% of total fuel use by the year 2030.
Going by the predictions, algae-derived biofuels have great potential to become a mainstream fuel once the manufacturers are able to overcome the initial barriers associated with capital cost, raw material manufacturing, and production volumes.
High potential associated with algae-derived biofuels coupled with the efforts made by the manufacturers is expected to open new avenues for the industry and address the growing demand for alternative fuel.