This document discusses sustainable development and the need to accelerate action on the UN Sustainable Development Goals (SDGs). It notes that while poverty and child mortality have decreased, hunger and economic losses from disasters are rising. Urgent action is needed on climate change as the last few years were among the warmest on record. The rest of the document focuses on biofuels from algal biomass, including what biofuels are, advantages over petroleum diesel, techniques for cultivating and processing algae into biodiesel, harvesting algal biomass, and extracting oil from algae. It concludes that algae is an efficient biodiesel source but requires further research to unlock its full potential and address challenges like

1. Presented by-
Keshav Ranjan (11716635)

3. The need for Sustainable Development
While extreme poverty has been reduced considerably in the past decades, there
are pockets in the world where it still stubbornly persists.
Worldwide, child mortality decreased substantially over the past several decades.
Child marriage has continued to decline around the world.
Ensuring access to affordable, reliable, and modern energy for all is one step
closer.
Despite efforts to reduce the risks from disasters, economic losses in 2017
attributed to disasters were estimated at over $300 billion.
Global hunger is on the rise after a period of prolonged decline.
Urgent action on climate change is imperative, as 2017 was one of the three
warmest years on record.
Seven reasons we need to step up action on the
SDGs:

4. What is a Biofuel?
• Biofuel (aka Agrofuel): Any fuel whose
energy is obtained through a process of
biological carbon fixation
• Carbon Fixation
• A chemistry process that converts
carbon dioxide into a hydrocarbon
molecule (a source of energy) that would
be found in a living organism
• If this process occurs in a living
organism, it is referred to as “biological
carbon fixation”
Photosynthesis is a biological carbon fixation process
utilized by plants to obtain energy in the form of
carbohydrates.
A Lesson Learned from Nature

5. Advantages over Petro-Diesel
• Renewable source
• Biodegradable/Nontoxic
• No Sulfur/High Lubricity
• Carbon Neutral (reduce carbon
footprint)
• Lower Flash Point
• Reduced Emissions

6. Beneficial Biofuels—The Food, Energy, and Environment Trilemma
The search for beneficial biofuels should focus on
sustainable biomass feedstocks that neither compete
with food crops nor directly or indirectly cause land-
clearing and that offer advantages in reducing
greenhouse-gas emissions.
The best biofuels make good substitutes for fossil energy.

7. Microalgae are prokaryotic or eukaryotic photosynthetic microorganisms that can grow rapidly and live in harsh
conditions due to their unicellular or simple multi-cellular structure.
• Algae are recognised as one of the oldest life-forms.
• They are primitive plants (thallophytes), i.e. lacking roots, stems and leaves, have no sterile covering of cells
around the reproductive cells.
• They have chlorophyll as their primary photosynthetic pigment.
Examples:
Prokaryotic microorganisms: Cyanobacteria (Cyanophyceae) Eukaryotic microalgae: Green algae (Chlorophyta) and
diatoms (Bacillariophyta)
Microalgae and Why it is used?

10. Technologies for the Production of
Microalgal Biomass and Biofuel

11. Algae can adventitiously be cultivated in diverse ways:
• Open ponds
Algae is grown in a pond in the open air
• Simple design and low capital costs
• Less efficient than other systems
• Other organisms can contaminate the pond and potentially damage or kill the
algae
• Closed-loop systems
• Similar to open ponds but not exposed to the atmosphere and use of a sterile
source of carbon dioxide
• Could potentially be directly connected to carbon dioxide sources (such as
smokestacks) and thus use the gas before it is every released into the
atmosphere
• Photobioreactors
• Complex, expensive, closed systems
• Significantly higher yield and better control
Techniques for Cultivating Algae

12. Three different designs of open pond systems
• Raceway pond
• Circular pond
• Unstirred pond
Closed-loop systems
Photobioreactors

15. Harvesting and drying of algal biomass

16. Flocculation and Ultrasonic aggregation

17. Harvesting by flotation

18. Gravity and Centrifugal sedimentation

19. Biomass filtration

20. Drying and Processing
Drying
 Harvested algae contain 97%-99% water.
 Removal of most of the water is necessary for long
term storage of the algae feedstock and is required
for many downstream processes.
 To keep algae from prolonged microbial growth,
the moisture level of the harvested algae should be
kept below 7%.
 Drying is an energy intensive process and can
account for up to 30% of the total production
costs.
 Natural drying (solar and wind) is the most
economical way; however, its weather dependent
nature could easily put the operation at risk of
spoilage.
 It requires a long time and labour.
Processing
 Extracting the oil and converting the oil from algae
to biodiesel are the primary driving force for algae
to fuels technology development.
 The oil extracted can be converted to biodiesel via
transesterification reaction.
 Nevertheless, the whole algae or the residues from
oil extraction are excellent feedstock for making
other fuels and products via different processes.
 For example, the starch and cellulose components
are suitable for ethanol fermentation.

21. Oil Extraction Methods
Oil Press Method
Hexane Solvent Method
Supercritical Fluid Extraction
Enzymatic Extraction
Ultrasonic Assisted Extraction

22. Oil Press Method:

24. Other uses of algal biomass as energy source
Ethanol fermentation of starch and cellulose in Algae
Thermochemical conversion
Gasification
Hydrothermal liquefaction and gasification
Anaerobic digestion

25. Bio-Diesel Hybrid
• GM Hybrid Bus
 EP system
 Clean Hybrid technology
 Hydrocarbon and carbon monoxide reduction
of about 90%
 Nitrous oxide reduction of about 50%
 Already in service in many cities
 Up to 60% improved fuel economy
Application

26. Advantages
• They are newer and dependable sources of energy.
• Biodiesel serves as a sustainable source of energy due to the lower carbon
footprint.
• Greenhouse Gases -The emission of greenhouse gases is low thus it does
not contribute much in the global warming.
• Energy Independent - If a country has enough area to develop a significant
amount of biomass and produce bio fuel from it, it makes that nation
energy independent.
• Economic Source - Biodiesel is an economic source as it requires cheaper
substrate and also generates jobs.
• Algal biomass - It is the best biomass which can be used, it produces an oil
which can easily be transformed into diesel.

27. Disadvantages
• Stability - The bio fuel derived from algal biomass possesses less stability
due to a high content of poly unsaturated fats.
• Mono culture problem - Production of single kind of biomass may pose a
threat of loss due to pest, water pollution, catastrophic failure.
• Water requirements - Whether is closed system or open ponds agal
biomass requires a significant amount of water.
• Surface area - Growing sufficient algal biomass requires a large surface
area.
• Fertilizer production is carbon dependent
• Relatively high upfront capital costs
• Not clear yet what the ultimate cost per gallon will be. Presently too high.

29. Conclusion
• Algae is a very efficient means of producing biodiesel.
• The oil production from algae farms is feasible and scalable.
• Further research necessary to unlock full potential of algae.
• Biodiesel has become more attractive recently because of its
environmental benefits and the fact that it is made from renewable
resources.
• With the increase in global human population, more land may be
needed to produce food for human consumption (indirectly via
animal feed).

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