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Hymn to AGNI the God of Fire

Hymn to AGNI the God of Fire. P.K. Kaw Institute for Plasma Research Bhat, Gandhinagar 382428, INDIA Ahmedabad 2004. Search for sources of energy.

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Hymn to AGNI the God of Fire

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  1. Hymn to AGNI the God of Fire P.K. Kaw Institute for Plasma Research Bhat, Gandhinagar 382428, INDIA Ahmedabad 2004

  2. Search for sources of energy • Has typically ended with an encounter with Fire – Agni in one of its manifestations –eitherfashioning fuels for storage or consuming them for energy release. • As we trace this history we stand in awe of AGNI – hence the title in praise of the Lord of Fire!

  3. Outline • Why the search ? • Muscle Power • Combustibles • Renewables • Nuclear Power • Future Options • Epilogue

  4. Why the search ? • Man does not live by bread alone ! Limited prowess but unlimited dreams. Needs a slave ( ENERGY) to help fulfill his dreams ! • Energy is also required for normal comfortable living :- heating, cooling, transporting, manufacture, cooking etc. • Quality of life ~ Electricity Consumption Huge gap. • Average consumption/person in developed world = 6000 KWH/year ~ 17 KWH/day • In India ~ 1 KWH/day.

  5. Units … • 1 KWH = 1 unit of electricity ~ Rs. 2- 4 This is equivalent to energy used in lifting 2000 bags of 100 Kg rice by 2 meters . • Energy that would be supplied by 6 slaves working full time. • Modern man needs energy equivalent of 100 slaves/person to live in comfort !!!

  6. Muscle Power • First source used by man. His own as well as that of slaves and animals. Pyramids, Galley ships …West upto 19th century . Has limited utility. • Source of energy ~ Food Average intake per person per day ~ 2500 Cals = 3 KWH. Mostly used up for the business of staying alive – keeping warm, repair and maintenance, growth etc.

  7. Muscle Power (Contd.) • We may be able to divert 10 % of energy during waking hours to do useful work = 0.3/2 = 0.15 KWH/day. • This explains why we need ~ 100 slaves to keep 1 modern man in comfort. • Not acceptable in free democratic world.

  8. How do animals (including man) do work and generate heat? Animals are controlled furnaces ‘slowly burning’ the fuel of food and generating energy: Sugars , fats etc. + O2 CO2 + H2O + energy Storage and heat (Food) (Respiration) Energy Storage Adenosine triphosphate (ATP) Adenosine diphosphate (ADP) Inorganic phosphate energy + +

  9. ATP is stored in muscles and converted into ADP and muscular energy (by contraction) + heat when we order the muscles to do work. Our first encounter with AGNI. Living matter is a slow fire (combustion!) converting energy trapped in food into a usable form. Also uses the strategy of employing special catalysts (enzymes) to give decent rates of reaction at near room temperatures!

  10. Combustibles • Discovery of Fire (direct encounter with AGNI ) 25000 years ago. • Natural fire – learnt to keep alive by adding combustibles (wood, dry leaves , fat etc.) ; ignition. • Heat (warmth) , light (security) , cook (health) , work , metals (improved weapons) . • First put to work in steam engines of 19th century – led to the industrial revolution and explosive growth of western civilization.

  11. Combustibles (contd.) • Thus began the age of Fossil fuels. • Internal combustion engine and generators of electricity invented. • Coal, Oil, Natural gas have become key commodities in the 20th century. • Availability and price of the fuels determines the pace of world economic development.

  12. Combustibles (contd.) • Can we depend on them in 21st century and beyond ? • Let us look at this question in a fundamental way! Fossil fuels (like coal, oil, gas) are hydrocarbons produced from plants and animal remains trapped by geological upheavals for millions of years under the earth. Like Food they release energy by combustion. Hydrocarbons +O2 CO2 + H2O + energy FIRE!!

  13. In either case (food or fossil fuels) energy is liberated because electronic linkages binding atoms in fuel are weaker than those in product molecules. Energy per carbon atom in CO2 Energy per carbon atom in fuel Energy released / carbon atom. Energy released/mol ~ few eV ~ 10-19 Watt secs. 1 gm. mol has 6 x 1023 mols.

  14. Total known reserves of fossil fuel ~ 1012 tons. ~ 1016 KWH of energy Energy required /year for world ~ 5 x 109 x 6000 KWH = 3 x 1013 KWH Reserves will last for for 1016/3 x 1013 ~ 300 years. Detailed estimates show that Oil will finish in 50 years , Gas in 100 years and Coal in 500 years.

  15. Energy in fossil fuels • Food and fossil fuel have energy stored in them in the form of weaker electronic linkages of atoms. Where did this energy come from? • It came from the SUN – that fierce manifestation of AGNI – in our skies. HOW? • Solar radiation was utilized by Chlorophyll (green colouring matter in plants) to carry out photosynthesis. CO2 + H2O + light energy O2 + sugars, carbohydrates

  16. Estimate of fossil fuel reserves Sun aims about 1017 Watts at earth. Of this 0.01 % is trapped by photosynthesis. About 10-6 of the plant matter is stored as Fossil fuels. 107 Watts for ~ billion years ~ 1017 KWH of fuels ~ 1013 tons. Gives an upper bound to fossil fuel reserve. Homage toThee, O AGNI in the form of SUN

  17. Problems with fossil fuels • It has taken almost a billion years to build these reserves and they can be squandered away in less than 500 years time. It is a wealth belonging to all future generations. Should we just burn it ? • Environment degradation, greenhouse effect, cost of clean up. • Uneven distribution (e.g countries with 6% of world population have 66 % oil wealth) leads to political tensions, wars! • Thus fossil fuel cannot be a long term solution .

  18. Fossil fuel era in the few thousand year history of mankind

  19. Renewables AGNI as Sun delivers a lot of energy to earth – albeit in a dilute form. 4 x 1016 W Evaporation, Precipitation, Storage in water cycle. (Hydro) 4 x 1014 W Winds, waves (Wind) 8 x 1016 W direct conversion to heat. (Solar) 4 x 1013 W Photosynthesis Storage in plants (Biomass)

  20. Hydropower Energy of moving water in rivers used since antiquity – water mills to grind corn, run irrigation systems, saw wood, run textile looms… Modern version is to run dynamos to generate electricity in hydroelectric power stations. Non – polluting, low running cost but limited because of geography. Potential capacity in India ~ 85 G Watts nearly 10 % of total requirement in future!

  21. Solar Power Too dilute and diffuse: Not suitable for centralized urban industrial complexes. Problems of storage of heat for night, cloudy days. Mostly residential use – solar cooker, water heater etc. Electricity plant ~ 35Mwatts/km sq feasible Solar photovoltaic – direct conversion of sunlight into electricity by semiconductor materials– relatively expensive, high maintenance and inefficient– has found applications in specialized niche areas like space vehicle power systems, remote places etc.

  22. Wind Power Limited applicability in certain areas with high wind velocity like coastal areas of Tamilnadu & Gujarat Biomass Fast growing cash crops used for direct burning or conversion into alcohols for use as liquid fuels or conversion into bio gas . Could be integrated with local rural economics. Not a major player in total energy scene but Significant social consequences for a country like India !

  23. Nuclear Energy Sun has been burning brightly for 5 billion years. It has spewed out 1017 Watts x 108 x 5 x 109 x 3 x 107 = 1042 Joules. ( 1 KWH = 3.6 Million Joules ) of energy. It has a mass of ~ 1033 gms. Even if every atom burnt in a chemical fire, rearranging electronic linkages, we would at best produce 1038 Joules.AGNI in sun is an unusual fire ! It is a thermonuclear fire !!

  24. Nuclear Energy Nuclear energy discovered in 20th century. Einstein showed that mass and energy are interconvertible. Here c is the velocity of light. Energy released Mass lost 1042 Joules of energy may be produced by loss of 1028 gms. i.e. 1/100,000 of the Sun’s mass. This mass loss would not have any other drastic consequence on Sun.

  25. Nuclear Fission and Fusion Bohr – Rutherford model already showed that the mass of atom is concentrated in nucleus. Hence nuclear reactions – as opposed to chemical reactions could change mass and release energy. Fission U + n fission fragments. Heavy nuclei Fusion D+T He +n +17.6 MeV. Light Nuclei Mass is lost and energy is released

  26. Energy/nucleon in Uranium Energy/nucleon in D, T Energy/nucleon in Fe nucleus.Most stable nucleus which is bound intensely. Nuclear energy released / nucleus ~ 106 times the chemical release /atom.

  27. Sun releases its energy by thermonuclear fusion of protons: 4 protons Helium + electrons + energy Need for high temperatures. Containment by gravitation on Sun. Fission and Fusion energy on earth Atomic and Hydrogen Bombs. Controlled reactors for Electricity Production.

  28. Fission Reactors Commercially exploited > 50 yrs France 75 % USA 25% Japan 33% Korea 40% India 3% 15% by 2020 Radioactive waste problem Radiation Hazard – 3 mile island, Chernobyll Fuel Proliferation

  29. Why Fusion ? • Fuel is limitless! D (1 part in 6000 of sea water) T bred from Lithium (earth’s crust +oceans) Gives energy security to all nations. • Waste Products minimal - reaction products non radio –active - neutron induced radio – activity in vessel etc. can be minimized by use of low activation materials. - radioactivity can be eliminated in advanced reactors (p-B, D- He3 etc.).

  30. Why Fusion ? • Inherently safe system. no chain reaction, melt down etc. • No dangers of proliferation • No Atmospheric pollution(no CO2 , GHG etc.)Tritium leakage problem minimal since it is continuously bred. With so many merits, stakes in the development of FUSION are Colossal !!

  31. How to achieve Fusion? D + T He +n +17.6MeV • Heat the fuel mixture to 100 million degrees and get conditions such that Density x Temp x confinement time > 5.1021m-3 keV secs. • Ignition of thermonuclear AGNI • He nuclei keep the fuel hot. Neutrons take energy out, trapped in blanket like fission reactor. • Mixture at sub-atmospheric densities (~1020 m-3) to be held and thermally isolated for seconds. Fuel is in a Plasma State

  32. Figure 4a Components of a fusion reactor

  33. Confining Plasma … • Can be held in cages made of non material magnetic field lines – Magnetic bottles. Ex: TOKAMAKS • Plasma heated by currents and microwaves. • Once the Fire ignites it stays hot and we simply keep adding more and more fuel.

  34. Figure 5 Progress in the critical parameters for fusion reactor experiments

  35. ITER: International thermonuclear Experimental Reactor • Is the flagship experiment being built at a cost of 5 billion US dollars • Original parties: US, Russia, Europe, Japan. • Recent Additions: China, Korea, Canada. • Each partner contributing around ½ billion dollars (Rs. 2500 crores). • Experiment ready by 2012. Will pave the way for DEMO ~ operational by 2030. • First commercial reactors available in 2035-2050.

  36. Our National Programme • Started in mid eighties at the Institute for Plasma Research, Gandhinagar. • First indigenously built tokamak ADITYA started operation in 1989. • ADITYA routinely makes a few million degrees hot artificial sun and holds it in magnetic cages for fractions of a second.

  37. Figure 7 ADITYA , the indigenously built tokamak at Institute for Plasma Research , Gandhinagar

  38. Our National Programme (contd.) • Our second generation experiment: Steady State superconducting tokamak SST1 will be ready for experiments in 2004. • Plasma temperature will be 20 –40 million degrees. It will be the first experiment in the world holding a hot tokamak plasma for 1000 seconds and will give a preview of some features of ITER physics on a small scale.

  39. Figure 8 SST 1 , the superconducting steady state tokamak , which will hold a fusion plasma for a 1000 seconds , being fabricated and assembled at Institute for Plasma Research , Gandhinagar

  40. Summary and Future Options • Muscle power and fossil fuel are out.Nuclear energy, specially thermonuclear fusion fire is definitely in. Renewables like hydro, wind, solar etc. are in but may play a subsidiary role. • New ideas on improved utilization of solar by genetically engineered accelerated photosynthesis/dissociation exist, e.g. work is going on development of algae/bacteria which would use sunlight and water as inputs and generate hydrogen as a product.

  41. Some Future Options (contd.) • Hydrogen is an excellent fuel – gas, readily transportable by pipes – produces non – polluting water in combustion. Hydrogen economy will take over from Carbon economy anyway! • Another attractive idea is to put solar power stations on satellites – - they would see sun all the times - they would not occupy valuable real estate. - would not be effected by dust, atmosphere etc. - would send concentrated energy through microwave beams to ground power stations.

  42. Fig. 9 The Solar satellite concept

  43. Some Future Options (contd.) • A dreamer, Freeman Dyson, has asked – Why should we be satisfied with 10-8 of Sun’s energy, which it aims at us? With improved engineering skills – trap all of Sun’s energy on spherical shell of material from Saturn at Jupiter’s orbit. Advanced civilizations may already be doing this.

  44. Figure 10 Our Sun surrounded by the Dyson sphere collecting all of sun’s radiation and beaming the energy to earth.

  45. Epilogue • Explorations into search for new sources of energy has led us into interesting alleys of fundamental science. • Most sources were traced to nuclear fire inside the Sun or some day in our reactors. • Where does energy trapped in nuclear fuels come from? • Genesis of elements – nucleosynthesis of light and heavy nuclei. • In the beginning there was the BIG BANG! The primordial FIRE or the earliest AGNI.

  46. Epilogue (contd.) • It started with a ball of radiation which expanded, cooled and formed a quark gluon plasma. As the ball cooled further, the quarks condensed into protons, neutrons and some of the lightest elements like He, Li, B … etc. • Heavier elements like C, N, O … are formed in the fusion furnaces of young stars. Elements beyond Fe are formed by neutron capture processes. • We see a rich variety of elements because cooking in the primitive universe and stars is imperfect. Perfect cooking would have led to Fe everywhere.

  47. What are we ? A deeper look at ourselves • Made of natural elements H, C, N, O … • Our atoms are billions of years old ! • Each H nucleus of my body was fashioned from quarks in that primeval AGNI 14 billion years ago. • Each C,N, O nucleus has been fashioned in the fusion furnace of some star, spewed out into space during its death – throes and picked up by the gas clouds from which our Sun and its planets have emerged.

  48. Thus we may verily say to AGNI: Thou art the Source And fashioned every limb of mine … Thou art the sustainer And provide energy to keep me together … And when I am ready to Sleep Into thy bosom will I disappear! In expressing our deepest yearnings, our sentiments are no different form our RIGVEDIC ancestors who sangHymns to AGNI!!

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