HYDROGEN GAS FROM POND SCUM - PowerPoint PPT Presentation

Loading...

PPT – HYDROGEN GAS FROM POND SCUM PowerPoint presentation | free to download - id: ae887-ODJjY



Loading


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation
Title:

HYDROGEN GAS FROM POND SCUM

Description:

... Microbial Biology, University of California - Berkeley and Botanisches Institut ... operate through different metabolic pathways when transferring elections. ... – PowerPoint PPT presentation

Number of Views:207
Avg rating:3.0/5.0
Slides: 63
Provided by: webpag5
Learn more at: http://webpage.pace.edu
Category:
Tags: from | gas | hydrogen | pond | scum

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: HYDROGEN GAS FROM POND SCUM


1
HYDROGEN GAS FROM POND SCUM
  • 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 planets ecosystems.
  • Unfortunately, a finite amount of fossil fuel has
    accumulated in the earths 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 worlds commercial energy is consumed
    by the United States, which uses 24 of the
    worlds energy, with only 4.6 of the worlds
    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
  • 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
    Earths Crust
  • They claim bacteria thrives in the light and
    oxygen deprived environment.
  • That depth is 8km below Russias 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 5- 10 microns in diameter
  • Chloroplast photon absorption
  • Light perceiving mechanism
  • Two anterior flagella for maneuvering in liquid
    5- 10 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 Worlds 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
Gaffrons 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. 740-748
  • 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
    algaes 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 suns 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 worlds
    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 centurys frontier for energy
    production and may prove to be as groundbreaking
    as Edisons 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 earths
    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.
About PowerShow.com