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Presentation on theme: "HYDROGEN GAS FROM “POND SCUM”"— Presentation transcript:

Using Green Algae to Create Sustainable Energy

2 Reaching for the Stars Finding an efficient and renewable method of producing Hydrogen gas has been a goal for those seeking a clean and efficient way to generate a plethora of heat and electricity.

3 Sustainability An energy producing resource is considered sustainable if it can be produced and used economically and safely, while meeting the demands of the present without compromising the ability of future generations to do the same. Accordingly, the resource must be replenishable and have a minimal impact on the environment. Sustainable energy resources are now recognized as the more the efficient way to produce energy.

4 Sustainable Systems Theory I
Striking a sustainable equilibrium between these systems has been a challenge faced by all civilizations because each system has a different goal or status to achieve. When the goals of these spheres collide in opposition, it leads to environmental degradation and a decline in the quality of life.

5 Sustainable Systems Theory II
Under this view, the ecosystem provides ecological limits for both the social and economic systems. Economic welfare is seen as a direct component of our social system that shapes the quality of life. This view is less ambiguous and describes the interrelations and respective limits of each system with more precision.

6 Inability to Maintain Sustainability
Anthropogenic activities place great stress on our planet’s ecosystems. Unfortunately, a finite amount of fossil fuel has accumulated in the earth’s crust over the course of many millions of years, which means the use of alternative sources of energy is the inevitable fate of our society. Most of the world’s commercial energy is consumed by the United States, which uses 24% of the world’s energy, with only 4.6% of the world’s population.

7 Oil Addiction

8 Oil Depletion and CO2 Emissions

9 C02 Emissions Per Person

10 Present Sustainable Energy Sources
Sustainable energy resources are now recognized as the more the efficient way to produce energy. There have been great strides in the field. For example, solar, wind, water, and biomass energy can be harnessed to provide heat and electricity, but many strides still have to be made before they can sustain the global energy demand. Disadvantages of solar power: low efficiency, high cost, and need steady access to sun. Disadvantages of wind power: steady winds required, land use intensive, visual pollution, noise, interference with migratory bird patterns. Disadvantages of using water power: construction costs, CO2 emissions from decaying biomass in shallow tropical reservoirs, floods, ecosystem conversions, danger of collapse, harms fish and mineralization. Disadvantages of biomass burning: may be nonrenewable, CO2 emissions, low efficiency, soil erosion, and water and air pollution.

11 Sustainable Breakthrough
A new source of sustainable energy is being developed which may revolutionize sustainable energy production It uses the peculiar properties of Green Algae found in common pond scum to create Hydrogen gas.

12 Introduction to Hydrogen Gas
Hydrogen gas power has long been heralded as the renewable energy source of the future because of its cost effectiveness and low environmental impact. Hydrogen gas plays a pivotal role in powering the universe through stellar hydrogen fusion, like our Sun. However, if generated by fossil fuels or nuclear power, it is falls outside the sphere renewable energy. The present methods by which Hydrogen gas is produced require a separate energy source to create that fuel.

13 Hydrogen Gas Molecule 1 H 1.008 Hydrogen gas is a molecule of the element Hydrogen. Hydrogen is the first element on the periodic table, and thus, has the lowest molecular weight.

14 The Hydrogen Gas Molecule
Two atoms of Hydrogen combine to form a hydrogen molecule. A typical H2 molecule consists of a single covalent bond. Each atom has one orbit, which overlap when combined.

15 Hydrogen Molecule in Nature
Although hydrogen is the most abundant element in the universe, (more than 75-90% of all atoms), very little Hydrogen gas is readily available is the Earth atmosphere, crust, or waters. Traditionally, it was thought that there was very little, if any, Hydrogen gas existing anywhere on Earth, however, a recent NASA discovery suggests that Hydrogen gas may exist 20km below the Earth’s Crust They claim bacteria thrives in the light and oxygen deprived environment. That depth is 8km below Russia’s record setting borehole which took 13 years to dig.

16 Algae Taking Over a Pond
Pond Scum is usually a type of algae. Generally, algae are microscopic organisms that live in aquatic environments

17 “Pond Scum” The vernacular term “pond scum” is extremely derogatory.

18 Algae and Humans Throughout human history these tiny organisms have been used as foods (e.g. nori, wakame) and medicines (e.g. agar-agar, carrageen, alginic acid).                                                                  

19 Magical Algae?

20 Three Major Divisions of Algae
Chlorophyta (green algae) - need plenty of light Phaeophyta/ Stramenopila (brown/golden algae) - can grow under low light conditions. Rhodophyta (red algae) – more exist than brown, golden and green algae combined

21 The Class of Chlorophyta
Of the studies conducted thus far, the class of Chlorophyta is capable of Hydrogen gas generation.

22 Green Algae Usually microscopic freshwater organisms or large seaweeds. Over 7,000 known species. The various species can be very diverse from each Thrive in different environments.

23 The Chlamydomonas Genus
The Chlamydomonas genus falls within the class of Chlorophyta. That genus proclivity has extended beyond fresh water environments, such as soil, fresh water, oceans, and even in snowy mountaintops. Here are two Chlamydomonas gametes mating.

24 Chlamydomonas reinhardtii
The most widely used laboratory species of algae. Basic biological functions have been well known for years. The biochemistry and physiology has been intriguing scientists for years because of some of its more peculiar properties.

25 Cell Structure Cell wall - clear to semi clear gelatinous-like layer microns in diameter Chloroplast – photon absorption Light perceiving mechanism Two anterior flagella for maneuvering in liquid – microns long Mitochondrion - respiration Starch granule – energy storage

26 General Survival Requirements
Carbon - obtained from carbon dioxide or hydrocarbonate (HCO3-) Nitrogen – obtained from nitrate ion (NO3-) Phosphorus – as some form of orthophosphate Sulfur – obtained from sulfate (SO4 –2) Trace elements including sodium, potassium, calcium, magnesium, iron, cobalt, and molybdenum.

27 Algae and Photosynthesis
Photosynthesis by algae is critical to: Aquatic food chains would suffer (from shrimps to whales - w/o algae, most sea life would die). Oxygen breathers, all of whom depend on these organisms as the largest supplier of Oxygen (created as a by-product during photosynthesis).

28 CO2 + H2O + light  C6H12O6 + O2

29 Stage 1- Light Dependant Reaction
Sunlight hits the chlorophyll pigment and causes the molecule to lose an electron, which must be replaced. This causes an enzyme in Photosystem II to split a molecule of water into Hydrogen ions and electrons, and Oxygen gas is released from the chloroplast. The electrons are passed to a chain of proteins called the electron transport chain. Usually, chemical energy in the forms of ATP and NADPH are generated.

30 Stage 2 – Calvin Cycle The light independent reaction occurs in the photosynthetic membranes of chloroplasts (stroma). Oxygen is not required. RUBISCO is a an enzyme that takes a molecule of CO2 and combines it with RuBP,a five carbon sugar (5C), to form a 6C intermediate, unstable sugar. NADPH adds electrons for glucose biosynthesis, while ATP generates energy for glucose biosynthesis. After a series of transformations, G3P (glyceraldehyde-3-phosphate) is then available to be converted into more stable sugars such as glucose, sucrose, and fructose to be catabolically consumed.

31 Catabolic Reaction Chemical reactions in catabolic pathways are what allow cells to thrive. If the reaction uses energy to break down a molecule to a simpler form, it is called catabolic. The goal is to break the glucose (created during photosynthesis) down into a storable form of energy (ATP) and electron (NAD) carriers. This reaction stimulates movement, growth, and repair.

32 Algae as an Oxygen Producer
The basic production of organic matter by algal photosynthesis involves the following reaction: C2O + H2O  {CH2O} + O2(g)  includes the energy of a quantum of light {CH2O} represents a unit of carbohydrate

33 Algae as an Oxygen Consumer
Algae does not depend on photosynthesis as its sole source of energy. In the absence of light algae is able to metabolize organic matter by utilizing stored oils, starches, or from the consumption of the algal protoplasm itself. During this metabolic process, the algae consume oxygen.

34 Eutrophication Living algae w/o light access consume oxygen
Decaying algae depletes oxygen levels Aerobic bacteria also consume organic waste, depleting oxygen levels. Oxygen consumption of any intensity in an aquatic life zone is detrimental to the entire food chain.                                                                                                                                                                          

35 “Now I see you for what you really are, Al G. – pond scum”

36 Is the World’s future energy source in the palm of our hands?

37 The Discoveries of Hans Gaffron
The ability of unicellular green algae to produce hydrogen gas was discovered over 60 years ago by Hans Gaffron a pioneer in the algae-hydrogen field who fled from Nazi Germany to the U.S. in 1939. The first successful attempts at hydrogen gas production in green algae were induced upon anaerobic incubation of cells in the dark. Because plant functions are at a minimum during darkness, production of H2 was minimal. A few years later, he was able to produce hydrogen gas later in a light mediated environment (“photohydrogen production”)with Chlamydomonas reinhardtii.

38 Algae and Bacteria The discovery of photohydrogen production uncovered that these eukaryotic organisms had retained some of the traits of their photosyntheic prokaryotic ancestors. Unlike normal photosynthesis these species can thrive in far red light. The understanding of these similarities led Gaffron to further success. For example, he would be the first to introduce the use of Hyrdogenase, the key enzyme in H2 production, that is contained in the DNA of algae and bacteria.

39 Fe Hydrogenase Complex multi-metal domain proteins/ enzymes of high molecular weight. Fe hydrogenase genes have been isolated in Chlamydomonas reinhardtii and showed unique structural properties.

40 Gaffron’s Attempt at Hydrogen Gas Generation Via “Photoproduction”
First, Fe Hydrogenase was encoded in to the nucleus of the unicellular green algae, which is linked to the electron transport chain in the chloroplast. After a few hours of an anaerobic induction, the enzyme activity began. Then, the light was restored because Hydrogen gas can only be created when electrons are being supplied to the electron transport chain via light energy. However, the activity of the hydrogenase lasts from only a few seconds to a few minutes and H2 production is limited.

41 Hydrogenase and Hydrogen Gas
It produces hydrogen, but only in the absence of oxygen. Therefore, Hydrogenase hydrogen production cannot occur when light is present because photosynthesis and oxidation are occurring. Finding a light-based method for generating Hydrogen gas in algae, while simultaneously containing oxygen generated during photosynthesis has been a challenge. Up until now, there had been relatively few advances in this biochemical field.

42 This Discoveries of Anastasios Melis and Thomas Happe
“Hydrogen Production. Green Algae as a Source of Energy” Plant Physiol, November 2001, Vol. 127, pp Department of Plant and Microbial Biology, University of California - Berkeley and Botanisches Institut der Universität Bonn, Germany

43 Lessons Learned From Past
Oxygen / Hydrogen Because of the Hydrogenase activity, it was decided that inhibiting Oxygen was the key to producing a sustainable and renewable source of Hydrogen gas from algae. The previous experiments had proved that Oxygen acted as a “cut off switch” for Hydrogen gas production. Sulfur / Oxygen Another collaboration of scientists had shown that removing sulfur from algae’s growth medium causes a specific but reversible decline in the rate of oxygenic photosynthesis, but does not effect the rate of mitochondrial respiration. This process was unknown before then.

44 The Groundbreaking Discovery
A hydrogen-producing C. reinhardtii culture. Hydrogen bubbles emanate toward the surface of the liquid medium. The gas is drained through a syringe (inserted in the middle of the silicone stopper) and, through teflon tubing, is collected in an inverted burette and measured by the method of water displacement.

45 Two Major Phases Photosynthesis phase - Chlamydomonas reinhardtii is grown under cool white fluorescents until the microorganisms reach a density of 3 to 6 million cells mL-1 in the culture. Sulfur Deprvation phase - The cells are deprived of sulfur which alters photosynthesis.

46 Phase One – Photosynthesis
During this phase the algae is provided enough sulfur to perform photosynthesis. Allows for storage of sugars, proteins, lipids and cellular matter. Sunlight hits the chlorophyll pigment and causes the molecule to lose an electron, which must be replaced. This causes an enzyme in Photosystem II to split a molecule of water into Hydrogen ions and electrons, and Oxygen gas is released from the chloroplast. The electrons are passed to a chain of proteins called the electron transport chain.

47 Phase Two – Sulfur Deprivation
Either carefully regulate the supply of sulfur in the growth medium so that is totally consumed, or Allow the cells to converge in the growth chamber before the growth medium is replaced one that lacks sulfur nutrients. This drastically alters the course of photosynthesis and respiration. Chlamydomonas reinhardtii cells switch to anaerobic fermentative metabolism within minutes.

48 Anaerobic Fermentation in Lightness
Fermentation is a degradation that usually occurs in darkness, and in environments devoid of oxygen. Sulfur-deprived and sealed cultures of become anaerobic in the light due to a significant and specific slowdown in the activity of the O2 producing Photosystem II. This is followed by an automatic induction of the Fe hydrogenase enzyme which beings the photosynthetic H2 production in the Photosystems and Electron Transport Chain.

49 Typical Photosystems II and I and Electron Transport Chain
Light, as photon energy, is absorbed by both photosystems, but at different levels The H2O splitting enzyme separates the hydrogen and oxygen. From Photosystem II to Photosystem I - energy is packaged as ATP. From Photosystem I to the stroma via the electron transport chain, the energy is packaged as NADPH. The spent electrons combine with protons and are accepted by an oxygen molecule (from the original splitting in PSII) to form water.

50 Photosystems and Electron Transport with Hydrogenase in Algae
Electrons derived upon the oxidation of endogenous substrate occurring in PS II feeds into the plastoquinone pool (PQ) Then, upon light absorption in PS I electrons become excited and are drawn to ferredoxin (Fd), which is an excellent electron donor. Those electrons are donated to the Fe Hydrogenase, instead going to NADPH The electrons are matched with protons to create molecular Hydrogen gas (H2).

51 Catabolic Reactions In the course of the fermentation significant amounts of internal starches and proteins are consumed. This sustains the algae cell with energy until the sulfur supply is reactivated, allowing for photosynthesis to recommence. Starch catabolism must also generate substrate for the cell's mitochondrial respiration.

52 Mitochondrial Respiration
Usually, mitochondrial respiration is an aerobic breakdown of organic matter within the mitochondria to produce ATP, carbon dioxide, and water molecules Here, mitochondrial respiration works differently as it scavenges the small amounts of O2 that evolve due to the residual activity of photosynthesis This ensures the maintenance of anaerobiosis in the culture. This is similar to how the mitochondria in photosynthetic bacteria functions.

53 Coordinated Phosphorylation
Photosynthetic and Respiratory Electron Transport occurs in a coordinated manner to produce H2. Chloroplast – photo-oxidation of water delivers electrons to the Hydrogenase causing photo-phosphorylation (use of sun’s energy to drive synthesis of ATP) and H2 production which is essential to sustain this coordination. Mitochodria – oxygen generated in chloroplast drives oxidative phosphorylation during respiration and permits continued anaerobisis (catabolism of starch yields electrons [4e] and the NADH is used to supply energy for ATP synthesis from ADP and NAD+). This ensures a “baseline level of photosynthesis” and energy production, which ensures the survival of the organism under stressful, sulfur deprived conditions.

54 Significance of Light Fermentation and Sulfur Deprivation
Light and dark fermentation operate through different metabolic pathways when transferring elections. The light fermentation pathways are more efficient than those found in higher plants, which typically struggle to survive w/o Oxygen present. Under Sulfur deprived conditions, Hydrogen gas is produced only in the light, not in the dark, by its “bleeding” through the algae cell. Fermentation is an energy producing process in which molecules serve as electron donors and acceptors. Under typical photo-autrophic conditions algae neither consumes, nor produces molecular forms of Hydrogen.

55 Four Interrelated Factors
Oxygenic photosynthesis - electrons are transported through the electron transport chain and eventually feed into the Fe hydrogenase. Endogenous substrate catabolism - starch, protein, and lipids yields substrate suitable for the operation of respiration in the mitochondria. Mitochondrial respiration - scavenges all oxygen generated by the residual photosynthesis and, thus, maintains anaerobiosis in the culture. Electron transport - via the hydrogenase pathway and the ensuing release of H2 gas by the algae sustains a baseline level of photosynthesis and, therefore, of respiratory electron transport

56 But, What Does It All Mean Basil?
In 2001, Melis Energy was to produce over 1 liter (same as 1 kg) of hydrogen per hour (24 kg per day) through a bioreactor containing 500 liters of water and algae. Energy storage: 1 kg of hydrogen = 113,500 BTU energy = 1 gallon of gasoline 1 kg of Hydrogen ~ 1 gallon of gasoline. Since a petroleum barrel consists of 42 kg of oil, in one day, one bioreactor can make half a barrel and more than enough gallons for several hydrogen gas powered automobiles.

57 Barrels of Energy Per Person
World energy use is approximately 65billion barrels of energy per year. 32.5 billion acres of algae to supply the world’s energy needs (10 times the size of Arkansas); 7.5 billion acres for U.S. needs (10 times the size of New Jersey). The vertical form of algae growth in a bioreactor reduces the need for intense land use.

58 Problems Problems: Elevating hydrogenase levels in the algal cells;
Reducing the oxygen sensitivity of the enzyme and maximizing the photosynthetic efficiency. The authors suggest that a study of the catalytic principle of hydrogenases may help develop better systems for efficient production of Hydrogen Gas.

59 The Future is Bright Although the present method of Hydrogen gas production is not the most efficient, it is in its infant stages and the technology will improve over the next 20 to 30 years. At that time it is possible is will be a viable substitute for oil fuel. This is a new frontier that must be explore further. Cars that run on hydrogen fuel cells have been developed, which are virtually pollution free. However, until now, that process involved the expensive extraction of Hydrogen via water electrolysis or processing of natural gas.

60 Policy Considerations
Our current energy crisis and the Greenhouse Effect mandate that energy alternatives such as this be implemented. As fossil fuel resource are depleted, the cost of efficiency of that mode of production will be surpassed by that of H2 production. Hydrogen fuel will efficiently replace traditional fuel for cars and heat for homes. It is the 21st century’s frontier for energy production and may prove to be as groundbreaking as Edison’s electricity discoveries were in the 20th century.

61 Corporate Opposition? Unless they are able to somehow gain control of Hydrogen gas production, corporations, such as these may seek to inhibit the growth of the Hydrogen gas industry. “The two most common things in the Universe are Hydrogen and stupidity.” – Harlan Ellison, author “There is more stupidity than Hydrogen in the Universe and it has a longer shelf life.” – Frank Zappa, musician

62 Conclusions Anastasios Melis - “I guess it's the equivalent of striking oil. It was enormously exciting. It was unbelievable.” This application of hydrogen gas will have a profound impact on a number of technological developments in power generation, agricultural, and automotive industries. It has the potential to create jobs and stimulate the economies of countries that produce this form of energy. If perfected, it will be inexpensive to produce because water and algae are virtually unlimited resources. It will reduce the degradation of the earth’s environment caused by mining and drilling for fossil fuels. Specifically, it will lead to the decline of the Greenhouse Effect because of its lack of CO2 pollution.


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