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Engineering Challenges in Algae Energy

Presented by Oilgae Team

(www.oilgae.com)

What am I here for?

To talk about– Alternative energy– Algae energy– Engineering challenges in algae energy


Alternative energy

Alternative Energy

• Alternative energy refers to energy sources which are not based on the burning of fossil fuels or the splitting of atoms.

• The renewed interest in this field of study comes from the undesirable effects of pollution both from burning fossil fuels and from nuclear waste byproducts.

Alternative energy

Various forms of alternative energy

ENERGY SOURCE

Renewable Energy Non Renewable

EnergyWind

Solar

Hydro

Bio Based

Geothermal

Ocean

Hydrogen

Energy from Waste

Traditional Alternative

Oil

Gas

Coal

Synfuel

Nuclear

Oil shale

Tar sands

Non renewable alternative energy

• Nuclear

• Synfuel

• Oil shale

• Tar sands

Nuclear energy

Nuclear energy is the energy that is trapped inside each atom.

Presently, nuclear energy provides for approximately 16% of the world's electricity.

Nuclear energy

Pros

1. Little Pollution 2. Reliability

3. Safety

Cons

1. Meltdowns 2. Radiation 3. Waste Disposal

Synfuel

• A gaseous, liquid, or solid fuel that does not occur naturally. Synthetic fuels can be made from coal, oil shale, or tar sands.

Synfuel

Pros-

• Produce gasoline, diesel or kerosene directly without the need for additional steps

• No need for new vehicles or convert engines to use a different fuel

• No need for new distribution network

• Less damaging to the environment

Cons-

Very expensive process

It contain only the one-third the energy content of solid coal.

Oil shale

• A sedimentary rock containing solid, combustible organic matter in a mineral matrix. The organic matter, often called kerogen, is largely insoluble in petroleum solvents, but decomposes to yield oil when heated.

• Pros

Potential to produce a superior liquid-fuel product.

less complex process

low sulfur content and therefore less air pollution

• Cons

Costs of fuel production from oil shale have not yet been fully evaluated.

Disposal of the used shale

Technology failures

Oil shale

Renewable alternative energy

Wind

Solar

Hydro

Geothermal

Hydrogen

Bio based

Solar energy

EPIA predicts solar will contribute 26% of total global energy needs by 2040.

Solar energy

PROS-• Saves money• Environmentally

friendly• Independent/ semi-

independent• Low/ no maintenance

CONS-• Potentially large

areas required• Not many places in

the world have enough constant and intense sunshine

• Initial cost

Wind energy

“The global wind market to grow by over 155% from its current size to reach 240 GW of total installed capacity by the year 2012”

-Global Wind Energy Council

The electricity produced by wind energy will reach over 500TWh in 2012 from 200TWh in 2007 accounting for around 3% of global electricity production

Wind energy

PROS-

• Clean• Efficient• Renewable

CONS-

Wind might not blow when we need it

• Hard to maintain• Too much space

Hydroenergy

Pros –

• No pollution • Most efficient energy

sources possible• Sustainable power • Economical

Cons –

• Change the local environment drastically

• Many acres of land being flooded

• Relocation of entire species that habitat the area

Hydroenergy - energy that is taken from water and converted to electricity

Geothermal Energy

Geothermal Energy provides approximately 0.4% of the world global power generation, with a stable long term growth rate of 5%.

Geothermal Energy

PROS-

1. Safe 2. Clean

3. Economical

4. Efficient

5. One power plant can produce a lot of steam by drilling more than one well

CONS-

1. May cause small after-shock earthquakes

2. Minor damage may take 1000 years to recover.

Hydrogen

Pros

• Hydrogen is an extremely clean fuel, producing few emissions when combusted directly or in combination with hydrocarbon fuels.

• When used in a fuel cell, the only byproducts are heat and water.

• Hydrogen has the highest energy per weight rating (good fuel)

Cons

• hydrogen is separated by a reforming process that uses natural gas and other fossil fuels.

• The technology to produce, store, and transport hydrogen power at a reasonable cost is not yet in place and likely will not be for some time.

Alternative energy

Current market potential

Biofuels

First generation biofuels

Feedstock such as soybeans, palm, canola and rapeseed are considered first generation feedstock for biodiesel production, as they were the first crops to be tried for biodiesel production. Most first generation biodiesel feedstock could be used alternatively to make food for humans as well.

First generation biofuels

Pros:

• Simple and well-known production methods

• Familiar feedstocks• Scalable to production

capacities• Easily blended with existing

petroleum-derived fuels• Experience with commercial

production and use in several countries

Cons:

• Feedstocks compete directly with crops grown for food

• Production by-products need markets

• Low land-use efficiency• Modest net reductions in fossil

fuel use and greenhouse gas emissions with current processing methods

Second generation biofuels

Non-food bio-feedstocks are considered as feedstock for second generation biodiesel. Either by using standard transesterification method, or by using technologies such as biomass to liquid (BTL), such feedstock could be converted to biodiesel.

Pros

• eliminates competition for food and feed

• more efficient and more environmentally friendly

• Less farmland is requiredmixture of crops can be useduseful by-products are produced which can be used in other chemical processes or burned for heat and power.

Cons

• same downfall as the first generation fuels but without as great of an eco imprint.

Second generation biofuels

• Third generation biofuels

Algae are considered to belong to the third generation of biodiesel feedstock.

Pros

• superior yields• not directly affecting the

human food chain• grown in places that are not

suitable for agriculture• enhanced efficiencies or

reduction in cost

Cons

– The problem of course is in developing technologies that will enable this kind of bioo fuel to be more cost effective to make.

Third generation biofuels

Algae energy

– The U.S. Department of energy’s Aquatic Species Programme, for example did over a decade of research (between 1978 and 1996), and found that algae were only economically viable as a biofuel at oil prices of more than $60 a barrel.

– Since 2002, there have been a number of commercial and research efforts in the algae energy field, and the activities have further accelerated starting 2008. While most of the efforts in the first few years focused on biodiesel as the end-product, recently a number of efforts have recently been initiated to explore the viability of using algae as feedstock for other energy products.

History of energy from algae

Why is the field of algae energy interesting?

Micro-algae are the fastest growing photosynthesizing organisms. They can complete an entire growing cycle every few days.

Under optimum growing conditions micro-algae are reported to produce up to 15,000 gallons of oil/acre/year.


Grown under conditions which are unsuitable for conventional crop production.


Capable of fixing CO2 in the atmosphere, thus facilitating the reduction of increasing atmospheric CO2 levels, which are now considered a global problem.

Algae biofuel is non-toxic, contains no sulfur, and is highly biodegradable.

Energy products from algae

BiodieselEthanolHydrogenMethaneBiomass – where algae biomass is directly used for combustionOther hydrocarbon fuel variants, such as JP-8 fuel, gasoline, biobutanol etc.

Biodiesel from algae

Cultivation of Microalgae species

Harvesting of Microalgae

Extraction of Oil from Microalgae

Transesterification

Biodiesel

Ethanol from algae

Fermentation

Algae Biomass

Ethanol

Hydrogen from algae

Biomass

Gasification Biogas Fermentation Dark Fermentation

Steam Reformation

H2

Methane from algae

Algal Biomass

Anaerobic digestion

Methane

Current status of fuel from algae

• Around 50 companies are working in this industry

• Around 45 universities are actively exploring the potential of algae

• Still in research level

• There is no commercialization yet



Various types of engineering challenges

Biological

Engineering challenges

Chemical Mechanical

Biological


- Strain selectionThe algal strains to be cultivated would be selected

based on productivity, and harvest ability, resistance to contamination, tolerance of high oxygen levels and temperature extremes.

Biological


- Maximize Photosynthetic Efficiency

Biological


- Increase the rate at which the algae grow, in order to harvest quickly

Biological


- Increasing lipid production of algae further

Biological


Devising suitable yeast for ethanol fermentation

Chemical

– Transesterication – Cost of chemical harvesting– Removal of toxic chemicals in waste water for algae

cultivation- Nutrients for algae


Transesterication

High FFA in algae oil could create transesterification problems .FFA’s create 3 major problems.

- More catalyst will need to be used leading to higher cost - Soap (fatty acid salt) is formed, making washing the finished product more difficult. - Water is formed which will retard the main reaction - The FFA’s are not converted into fuel, reducing the yield

So It is essential to treat the High FFA oil prior to transesterifiation.


Challenges in each and every process:


Algae cultivationOpen/Raceway pondPhotobioreactor

Algae HarvestingDrying of algaeOil extractionFermentationGasification

Algae Cultivation – Open pond / Raceway pond

• Growing algae in open ponds can lead to mal-odour in the ponds. This problem is mainly a result of lack of oxygen.

• Open ponds can get contaminated. • Control in aeration• Efficient and energy intensive mixing• Design and engineering of cost effective open pond culture systems • Loss of water due to evaporation• Too much sunlight can kill algae. So it is essential to control the

amount of sunlight falling on the algae cultivation area• Light penetration and problem of shading


Algae Cultivation – Open pond/Raceway pond

Algae Cultivation - Photobioreactor


• Algae Cultivation - Photobioreactor

With respect to system design, the technical challenges include:

(1) reducing capital and operating costs,

(2)maintaining temperature and pH control,

(3)Removal of oxygen from the growth system

(4)assessing water requirements (source, recycle, chemistries and evaporation issues),

(5)determining CO2 availability and delivery methods,

(6)Algae cultivation systems need to cost-effectively and evenly distribute light within the algae culture.

Algae Harvesting


Harvesting

Harvesting algae is much more difficult and energy intensive

Cost of harvesting (where centrifuges or flocculants are used, the costs could be significant)

Ability to determine the right time to extract oil from feedstock is critical. Current methods to determine these are expensive, time consuming and unreliable

Scaling up of harvesting systems

Drying of Algae


• Drying

Methods of drying other than Solar are highly expensive

Solar drying cannot be applied always

Solar drying is a slow process

High energy requirement

Algal Oil Extraction

Algae organisms are protected by a tough cell wall. That wall must be cracked - an energy-expensive process - to extract the oil. The challenge is to maximize oil yield by cracking as many of the algae cells as possible with the smallest amount of energy.

Oil Extraction -Challenges


Fermentation of Algal Biomass

Fermentation


Low cost Fermenters

Devising Closed loop reactors for recirculation of CO2 produced

Automation of fermentation followed by distillation process

Gasification of Algal biomass


• Gasification

Very high capital cost

EROEI – not clear

Conclusion

“Algae energy has excellent potential as a source of alternative energy but there are significant engineering challenges to be

overcome”

Thank you