Algae Fuel | New method to make bio fuels | Alternative to liquid fossil fuels

Algae - based bio fuel is a new energy source that has been getting a lot of attention lately. Algae fuel, algal bio fuel, or algal oil is an alternative to liquid fossil fuels that uses algae as its source of energy-rich oils. Also, algae fuels are an alternative to commonly known bio fuel sources, such as corn and sugarcane. 

Several companies and government agencies are funding efforts to reduce capital and operating costs and make algae fuel production commercially viable.

The energy crisis and the world food crisis have ignited interest in alga-culture (farming algae) for making bio-diesel and other bio fuels using land unsuitable for agriculture. Among algal fuels' attractive characteristics are that 

• they can be grown with minimal impact on fresh water resources, 
• can be produced using saline and wastewater, 
• have a high flash point, 
• and are biodegradable and relatively harmless to the environment if spilled. 

Algae cost more per unit mass than other second-generation bio fuel crops due to high capital and operating costs, but are claimed to yield between 10 and 100 times more fuel per unit area.

Producing bio fuels from algae is still in a pre-commercial state of technology development. But algae-based bio fuels are considered to be a promising upcoming alternative to fossil fuels as they could reduce GHG emissions when compared to fossil fuels.

Introduction:

Algae include a diverse group of microorganisms and occur in a variety of natural habitats, including terrestrial habitats such as soil and aquatic habitats ranging from freshwater and brackish waters to marine and hyper-saline environments. Biofuel from algae may be produced from microalgae, macroalgae, i.e. seaweed, or cyanobacteria. 

Cultivation of microalgae and cyanobacteria can be done through so-called photoautotrophic methods in open or closed ponds or through heterotrophic methods. Photoautotrophic refers to the fact that in these processes algae need light to grow and generate new biomass. In a heterotrophic process, algae are grown without light and feed on carbon sources, for example sugars, in order to create new biomass.

Feasibility of technology and operational necessities top: 

To grow optimally, microalgae need specific environmental conditions in terms of light, temperature ranges, CO₂ concentrations, nutrient compositions and salinity. Today, the main barrier to the production of bio fuels from algae is costs.

Specifically for developing countries, additional considerations include :

• Producing algae for bio fuels (excluding simple seaweed production) requires significant capital investments, which may be a significant barrier in countries with weak investment climate.
• Producing bio fuels from algae is still in a pre-commercial state of technology development. Most production plants are therefore prototypes, and the development and engineering of such plants requires a high level of expertise. Similarly, R&D efforts for example with the aim to increase the productivity of algae production or to reduce production costs, also requires a high level of knowledge and experience.
• While operation and maintenance itself, as well as processing of algae biomass are not expected to require very specific knowledge, planning of economic viability and of plant productivity remains a challenge.
• Large-scale facilities are more economically competitive, but there is a higher likelihood of social and environmental impacts.

Advantages:

• Algae may offer higher biomass yields per acre of cultivation than traditional bio fuels.
• Algae cultivation may minimize or avoid competition for arable land used for conventional agriculture and food production.
• Algae may be grown using waste water, and saline water, which may reduce competition for limited freshwater supplies.
• Algae can recycle carbon, for example by using CO₂ from stationary sources, such as power plants and other industrial emitters.
• Micro-algal production doesn’t require insecticides or herbicides, therefore there is no risk of generating pesticide waste.
• Combustion of algal bio fuel does not produce any sulphur oxides and produces less carbon monoxide than fuels like diesel and petroleum.
• CO₂ released into the atmosphere can be absorbed by the algae that is being cultivated. Even though CO₂ will be emitted when the algae is burned, the absorption during the growth phase means that algae has the potential to reduce net emissions of CO₂ in comparison to other fuel sources.