**3. Classification of biofuels**

The contribution of algal biofuels to future liquid transportation fuel supply is assessed against the *US Energy Information Agency* growth projections. By 2030, oil consumption is expected to increase to ca. 6.2 TL yr-1(106 million bbl d-1) with66 % of this growth likely to occur in non-OECD countries in *Asia*. Transportation fuel use is expected to grow slightly to ca. 56% of total oil production. Over the same time period, biofuels will maintain a relatively steady share of unconventional liquid fuel production and grow to between 277 GL/yr & 416 GL/yr (4.8 to 7.2 million Bbl/d, or 8.0% to 12.0% of the liquid transportation fuel supply). The EIA uses a figure

A 5% contribution of algal biofuels to total biofuels supply by 2030 would require the con‐ struction of 170 100 ML facilities. When the technical uncertainty is considered it seems unlikely that the first large scale plant would be commissioned before the middle of the coming decade, and even this would be ambitious. Approaches that rely on molecular biology to achieve breakthroughs, e.g., the partnership between *Synthetic Genomics Inc*. and *ExxonMobil Corp*., are promising but will likely take more than a decade to reach commercial viability. Assuming success in the first commercial venture and accelerated rates of adoption beyond 2015-2020, 170 100 ML facilities could conceivably be operational by 2030 as this rate of construction is lower than the recent development rate of ethanol plants in the *US* and *Brazil*. The forty-plus companies tackling the concept of algae production on a large scale for energy use have begun to differentiate into market niches, generally according to their founding

Companies where the founding members had deep pharmaceutical or bioengineering expertise tend to build their business models around proprietary genetically modified organisms and closed systems. Examples include *Synthetic Genomics, Solazyme, LS9, Targeted Growth, Inc., Amyris, Heliae Development*, and *Algenol*. Companies derived from other industries such as defense, wastewater treatment, and agriculture tend to prefer open pond systems and natural strains. Examples include *General Atomics, SAIC, HR Biopetroleum/Cellana, Aquaflow*

Companies headquartered in colder latitudes tend to focus on closed algae production systems. Examples include *Solazyme, Amyris Biotechnologies, Algae@Work, Algaedyne,* Heliae, and *Greenfuels Technologies Inc* (now defunct). Companies headquartered in warmer latitudes tend to focus on open-pond photosynthetic systems. Examples include *Sapphire Energy, General*

Some companies are pursuing a hybrid approach. One example is *Ohio-based Phycal Inc*., which plans to use an open-pond system at its *Hawaii* demonstration site to grow out the algae, then put them into a closed heterotrophic for "fattening" prior to harvest. *HR Biopetroleum/Cellana* also uses a hybrid system, where the seedstock are grown in closed photobioreactor systems to reduce contamination and then inoculated into open ponds for bulking up in volume prior

Every algae company has at least one other major revenue stream in its business model beyond just lipid production for biofuels markets. That co-product tends to affect its selection of sites, strains, production processes, etc. Some examples include a valuable co-product stream from

*Atomics, HR Biopetroleum/Cellana, SAIC*, and *Seambiotic* in *Israel*.

of ca. 340 GL/yr as a reference case for total biofuel production in 2030.

technical expertise and physical location.

104 Biofuels - Status and Perspective

*Bionomics,* and *Phyco Biosciences*.

to harvest.

In three generation of biofuels, First-generation biofuels are the biofuels which are directly related to a biomass that is generally edible. First-generation biofuels are in trend around the world and these are also economically viable, but there are some issues related to this kind of biofuels such as utilization of arable lands which are directly affect food availability in most of poor countries so it leads food versus fuel debate. In some countries where sugar market play vital role in their economy the production of ethanol from sugarcane is facing competition with sugar market and on the other hand where ethanol from corn is also responsible for increasing value of food on the world's market. Some problems are with biodiesel market, which is limited by the price of vegetable oils. So these are some reasons which are leading interest towards second generation biofuels.

Second generation biofuels are also known as advanced biofuels. In this type of biofuels, various types of biomass can be used as a feedstock for manufacturing of biofuels. Biomass is source of organic carbon that is part of carbon cycle so it is available as renewed after com‐ pletion of carbon cycle and is produced from a generally less expensive biomass such as animal, forest, agriculture or municipal wastes. Generally these biomasses are residual non food parts of crops that are not used for food purpose and food crops can be used as second generation biofuels, if they have already fulfilled their food purpose.

Two transformative technologies for production of second generation biofuels are usually done:

*Biochemical:* in this modification of the bio-ethanol fermentation process including a pretreat‐ ment process and

*Thermochemical:* in this modification of the bio oil process to produce methanol, fisher – Tropsch diesel or dimethyl ether.

Third generation biofuels are produced from extraction oil of algae. Its production has a very high growth yield and low cost. There are many advantage associated with third generation biofuels production such as fastest growing biomass, less land required compared to agricul‐ ture product used in other generation and some environment benefits like it cleans water it uses by removing nutrients & other pollutants, adds oxygen and it consumes CO2.
