Insights into Algae Biorefinery

High oil prices, competing demands between foods and other biofuel sources, and the world food crisis, have ignited interest in algaculture (farming of algae) for making vegetable oil, biodiesel, bioethanol, biogasoline, biomethanol, biobutanol and other biofuels. Algae can be efficiently grown on land that is not suitable for agriculture and hold huge potential to provide a non-food, high-yield source of biodiesel, ethanol and hydrogen fuels.

Several recent studies have pointed out that biofuel from microalgae has the potential to become a renewable, cost-effective alternative for fossil fuel with reduced impact on the environment and the world supply of staple foods, such as wheat, maize and sugar.

What are Algae?

Algae are unicellular microorganisms, capable of photosynthesis. They are one of the world’s oldest forms of life, and it is strongly believed that fossil oil was largely formed by ancient microalgae. Microalgae (or microscopic algae) are considered as a potential oleo-feedstock, as they produce lipids through photosynthesis, i.e. using only carbon , water, sunlight, phosphates, nitrates and other (oligo) elements that can be found in residual waters. Oils produced by diverse algae strains range in composition. For the most part are like vegetable oils, though some are chemically similar to the hydrocarbons in petroleum.

Advantages of Algae

Apart from lipids, algae also produce proteins, isoprenoids and polysaccharides. Some strains of algae ferment sugars to produce alcohols, under the right growing conditions. Their biomass can be processed to different sorts of chemicals and polymers (Polysaccharides, enzymes, pigments and minerals), biofuels (e.g. biodiesel, alkanes and alcohols), food and animal feed (PUFA, vitamins, etc.) as well as bioactive compounds (antibiotics, antioxidant and metabolites) through down-processing technology such as transesterification, pyrolysis and continuous catalysis using microspheres.

Algae can be grown on non-arable land (including deserts), most of them do not require fresh water, and their nutritional value is high. Extensive R&D is underway on algae as raw material worldwide, especially in North America and Europe with a high number of start-up companies developing different options.

Most scientific literature suggests an oil production potential of around 25-50 ton per hectare per year for relevant algae species. Microalgae contain, amongst other biochemical, neutral lipids (tri-, di-, monoglycerides free fatty acids), polar lipids (glycolipids, phospholipids), wax esters, sterols and pigments. The total lipid content in microalgae varies from 1 to 90 % of dry weight, depending on species, strain and growth conditions.

Algae-based Biorefinery

In order to develop a more sustainable and economically feasible process, all biomass components (e.g. proteins, lipids, carbohydrates) should be used and therefore biorefining of microalgae is very important for the selective separation and use of the functional biomass components.

The term biorefinery was coined to describe the production of a wide range of chemicals and bio-fuels from biomass by the integration of bio-processing and appropriate low environmental impact chemical technologies in a cost-effective and environmentally sustainable. If biorefining of microalgae is applied, lipids should be fractionated into lipids for biodiesel, lipids as a feedstock for the chemical industry and essential fatty acids, proteins and carbohydrates for food, feed and bulk chemicals, and the oxygen produced can be recovered as well.

The potential for commercial algae production, also known as algaculture, is expected to come from growth in translucent tubes or containers called photo bioreactors or in open systems (e.g. raceways) particularly for industrial mass cultivation or more recently through a hybrid approach combining closed-system pre-cultivation with a subsequent open-system. Major advantages of a algal biorefinery include:

  • Use of industrial refusals as inputs ( CO2,wastewater and desalination plant rejects)
  • Large product basket with energy-derived (biodiesel, methane, ethanol and hydrogen) and non-energy derived (nutraceutical, fertilizers, animal feed and other bulk chemicals) products.
  • Not competing with food production (non-arable land and no freshwater requirements)
  • Better growth yield and lipid content than crops.

Indeed, after oil extraction the resulting algal biomass can be processed into ethanol, methane, livestock feed, used as organic fertilizer due to its high N:P ratio, or simply burned for energy cogeneration (electricity and heat). If, in addition, production of algae is done on residual nutrient feedstock and CO2, and production of microalgae is done on large scale in order to lower production costs, production of bulk chemicals and fuels from microalgae will become economically, environmentally and ethically extremely attractive.

The Promise of Algae

This year has witnessed the U.S. Navy debut their “Great Green Fleet,” the first aircraft carrier strike group powered largely by alternative, nonpetroleum-based fuels, the British Ministry of Defence launch a competition to reduce its equipment energy spend and the Pentagon increase its investment in clean-energy technologies, including biofuels development.  Could we be witnessing the start of the end of our reliance on “fossil fuel” petroleum?

In 2010, the MOD spent £628m on equipment energy and, for every 1p per litre rise in the price of fuel, the MOD’s annual equipment energy bill increases by £13m. These rising oil prices have once again positioned biofuels centre stage as a potential substitute to fulfil our global thirst for fuel.

With so many biofuel crops needing to compete for space and freshwater supplies with agriculture, algae are being seen as an ideal, sustainable alternative.  Algae can be grown in areas where crops cannot, but until now, it’s been difficult to achieve the scale needed for commercial  algal production.

Leading international authority on algal biotechnology and head of the Culture Collection of Algae and Protozoa (www.CCAP.ac.uk), Dr John Day, thinks it’s a major step forward.  Dr Day has over 25 years’ experience in biotechnology and applied algal research and comments “Commercial confidence in the scalability of algal biofuel production is an exciting step forward in the journey towards sustainable, economic biofuel production using microalgae.

Algae Cultures at the Scottish Association for Marine Science

“A major driver for the development of algal biofuels has been fuel security and the US Navy has successfully tested nearly all of its ships and aircraft on biofuel blends containing algal oils — including an F-18 fighter flying at twice the speed of sound and a ship moving at 50 knots.”

“Scientists at SAMS and elsewhere have been contributing to the global development of knowledge on algal biofuel. It is this understanding of the biology of these enigmatic microbes and our capacity to successfully cultivate them that will be the key to producing algal biofuels and other products.”

Driven by the desire to reduce reliance on foreign countries for petroleum, and the constant pressure to reduce costs, Governments are taking sustainable fuels very seriously.  (A recent report highlighted that Pentagon investment in green technologies rose to $1.2 billion, up from $400 million, and is projected to reach $10 billion annually by 2030.)  The Pentagon’s Defence Advanced Research Projects Agency (which finances and monitors research into algae fuels,) says it has now managed to produce algafuel for $2 per gallon and that it will produce jet aircraft quality algafuel for $3 per gallon by 2013. Unsurprisingly, commercial aviation companies around the world are also taking an interest in algae biofuels to reduce their own costs and carbon footprints.

As interest grows and more funding becomes available, the industry is blossoming and more skilled people are needed. Could we witness a global shift to sustainable fuels in our lifetime?  We certainly hope so.

What is Algaculture

High oil prices, competing demands between foods and other biofuel sources, and the world food crisis, have ignited interest in algaculture (farming algae) for making vegetable oil, biodiesel, bioethanol, biogasoline, biomethanol, biobutanol and other biofuels, using land that is not suitable for agriculture. Algae holds enormous potential to provide a non-food, high-yield, non-arable land use source of biodiesel, ethanol and hydrogen fuels. Microalgae are the fastest growing photosynthesizing organism capable of completing an entire growing cycle every few days. Up to 50% of algae’s weight is comprised of oil, compared with, for example, oil palm which yields just about 20% of its weight in oil.

Algaculture (farming of algae) can be a route to making vegetable oils, biodiesel, bioethanol and other biofuels. Microalgae are one-celled, photosynthetic microorganisms that are abundant in fresh water, brackish water, and marine environments everywhere on earth. The potential for commercial algae production is expected to come from growth in translucent tubes or containers called photo bioreactors or open ocean algae bloom harvesting. The other advantages of algal systems include:

  • carbon capture from smokestacks to increase algae growth rates
  • processing of algae biomass through gasification to create syngas
  • growing carbohydrate rich algae strains for cellulosic ethanol
  • using waste streams from municipalities as water sources

Algae have certain qualities that make the organism an attractive option for biodiesel production. Unlike corn-based biodiesel which competes with food crops for land resources, algae-based production methods, such as algae ponds or photobioreactors, would “complement, rather than compete” with other biomass-based fuels. Unlike corn or other biodiesel crops, algae do not require significant inputs of carbon intensive fertilizers.  Some algae species can even grow in waters that contain a large amount of salt, which means that algae-based fuel production need not place a large burden on freshwater supplies.

Several companies and government agencies are funding efforts to reduce capital and operating costs and make algae fuel production commercially viable. Companies such as Sapphire Energy and Bio Solar Cellsare using genetic engineering to make algae fuel production more efficient. According to Klein Lankhorst of Bio Solar Cells, genetic engineering could vastly improve algae fuel efficiency as algae can be modified to only build short carbon chains instead of long chains of carbohydrates.

Sapphire Energy also uses chemically induced mutations to produce algae suitable for use as a crop. Some commercial interests into large-scale algal-cultivation systems are looking to tie in to existing infrastructures, such as cement factories, coal power plants, or sewage treatment facilities. This approach changes wastes into resources to provide the raw materials, CO2 and nutrients, for the system.

Prospects of Algae Biofuels in Middle East

Algae biofuels have the potential to become a renewable, cost-effective alternative for fossil fuels with reduced impact on the environment. Algae hold tremendous potential to provide a non-food, high-yield, non-arable land use source of renewable fuels like biodiesel, bioethanol, hydrogen etc. Microalgae are considered as a potential oleo-feedstock, as they produce lipids through photosynthesis, i.e. using only CO2, water, sunlight, phosphates, nitrates and other (oligo) elements that can be found in residual waters.

Algae also produce proteins, isoprenoids and polysaccharides. Some strains of algae ferment sugars to produce alcohols, under the right growing conditions. Their biomass can be processed to different sorts of chemicals and polymers (Polysaccharides, enzymes, pigments and minerals), biofuels (e.g. biodiesel, alkanes and alcohols), food and animal feed (PUFA, vitamins, etc.) as well as bioactive compounds (antibiotics, antioxidant and metabolites) through down-processing technology such as transesterification, pyrolysis and continuous catalysis using microspheres.

Microalgae are the fastest growing photosynthesizing organism capable of completing an entire growing cycle every few days. Up to 50% of algae’s weight is comprised of oil, compared with, for example, oil palm which yields just about 20% of its weight in oil. Algae can be grown on non-arable land (including deserts), most of them do not require fresh water, and their nutritional value is high. Extensive R&D efforts are underway worldwide, especially in North America and Europe, with a high number of start-up companies developing different options for commercializing algae farming.

Prospects of Algae Biofuels in the Middle East

The demand for fossil fuels is growing continuously all around the world and the Middle East is not an exception. The domestic consumption of energy in the Middle East is increasing at an astonishing rate, e.g. Saudi Arabia’s consumption of oil and gas rose by about 5.9 percent over the past five years while electricity demand is witnessing annual growth rate of 8 percent. Although Middle Eastern countries are world’s leading producers of fossil fuels, several cleantech initiatives have been launched in last few years which shows the commitment of regional countries in exploiting renewable sources of energy.

Algae biofuels is an attractive proposition for Middle East countries to offset the environmental impact of the oil and gas industry. The region is highly suitable for mass production of algae because of the following reasons:

  • Presence of large tracts of non-arable lands and extensive coastline.
  • Presence of numerous oil refineries and power plants (as points of CO2 capture) and desalination plants (for salt reuse).
  • Extremely favorable climatic conditions (highest annual solar irradiance).
  • Presence of a large number of sewage and wastewater treatment plants.
  • Existence of highly lipid productive microalgae species in coastal waters.

These factors makes it imperative on Middle East nations to develop a robust Research, Development and Market Deployment plan for a comprehensive microalgal biomass-based biorefinery approach for bio-product synthesis. An integrated and gradual appreciation of technical, economic, social and environmental issues should be considered for a successful implementation of the microalgae-based oleo-feedstock (MBOFs) industry in the region.