The Inconvenient Reality: The Impact of Alternative Energy on Agriculture and Key Materials

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1 The Inconvenient Reality: The Impact of Alternative Energy on Agriculture and Key Materials P.D. Clark Director of Research, ASRL and Professor Emeritus of Chemistry, University of Calgary Electricity Coal, Gas and Oil Liquid fuels (Transportation) Steel Cement (Concrete) NH 3 Asphalt Polymers Silicon Infrastructure Fertilizer Highways PV Solar Electronics Wind turbines 1

2 Topics For Discussion Why are oil, gas and coal so important to an industrialized economy? Why have we not already made the transition to non-fossil fuel energy? Can wind and solar energy meet our goals? Is nuclear power the answer? Can we feed ourselves without fossil fuel? [No] 2

3 Key Industrial Processes Natural Gas Crude Oil Sweet Sour H 2 S Processing H 2 CH 4, [C 2+ ] H 2 O CH 4, CO 2, H 2 S Sulfur (Air) Gasoline Diesel CO / H 2 H 2 N 2 CH 3 OH, petrochemicals liquid fuels Air Phosphate ore Sulfuric acid Jet fuel Fuel oils Petrochemicals Olefins (C 2 C 4 ) Aromatics (B, T, X) NH 3 Ammonium phosphate fertilizer Phosphoric acid Petchem derivatives Polymers 3

4 Worldwide Production of Sulfur (2016) Sour natural gas [CH 4 H 2 S CO 2 ] Sour crude oil Mt per annum Oil sand bitumen Metallurgical ore smelting * * Produced as H 2 SO 4 (72 Mt / a) Fossil fuel supplies > 95% of the World s elemental sulfur 4

5 Io Lot s of Sulfur If We run Out! 5

6 Venus Sulfuric Acid When We Need It 6

7 A Brief History of Agriculture Time Line (years, bp) End of last ice age 13,000 Human settlements, rudimentary farming 12,000 Wooden ploughs/animal labor 8,000 6,000 Fertilizer (manure) 7,000 Crop selection (yield) 8,000 Pigs, goats, chickens 2,000 New World / Asian crops 1,000 Dates Natural fertilizers (guano) Fossil fuel powered tractor ~ 1,900 Artificial fertilizer (NH 3, phosphates, potash) ~ 1,950 Improved mechanization ~ 1,950 7

8 Harvesters 8

9 Agriculture: The World s Most Important Industry Fertilizers N - NH 3 50% of the N in our bodies arises from Haber-Bosch process [N H 2 2 NH 3 ]. Supplied as urea, NH 3 and ammonium nitrate P - Used as soluble ammonium phosphates, manufactured by digestion of complex calcium phosphates with H 2 SO 4 K - From potash [KCl, K 2 O derived salts] S - Applied as S 8 or (NH 4 ) 2 SO 4 Sulfur is the limiting element because H 2 SO 4 digestion of insoluble phosphates is the only viable route to soluble P 9

10 Population, Energy and Commodity Production Population: Energy Consumption: (Exajoule per annum) (Exa= ) ~ 2.2 billion ~ 3.6 billion ~ 6.0 billion ~ 7.8 billion ~ 100 ~ 280 ~ 480 ~ 600 Sulfur Production/ Consumption: (Excluding SO 2 ore smelting) (mt/a) NH 3 Production/ (mt/a) ~ 6 ~ 25 ~ 50 ~ 75 ~ 5 ~ 40 ~ 100 ~ 160 Population increase demands increased energy supply which, using fossil fuel, provides the necessary sulfur and NH 3 Sulfur and NH 3 are the cocaine of the masses 10

11 Power Density and the Feasibility of Electricity Generation From Alternative Sources POWER SOURCE POWER DENSITY (W / m 2 ) Low High Natural gas Coal Solar (PV) Solar (CSP) 4 10 Wind Biomass Nuclear fission (?) References: V. Smil, Energy in Nature and Society: General Energetics of Complex Systems, MIT Press 2008 V. Smil, Power Density Primer: Understanding the Spatial Dimension of the Unfolding Transition to Renewable Electricity Generation [ 11

12 Manufacture of a Wind Turbine Blades: glass fibre in a polymer matrix (polyester, vinyl, epoxy) Steel column Reinforced concrete (steel, cement) Electricity is distributed via a grid system dependent on steel and concrete 12

13 Manufacture of Iron (Steel) Off gases [N 2, CO 2, CO, NH 3, H 2 S, HCN] Iron ore (Fe 2 O 3 ) C + O 2 CO / CO 2 (Coke) Coke Fe 2 O 3 + 3CO 2Fe + 3CO 2 Coal Hot air Molten Fe Off-gases contain H 2 S, NH 3, CO, H 2 and organics Replacement of coal/coke by charcoal from wood would require the World s entire wood output (V. Smil, Power Density 2015) 13

14 Electricity Generation Using PV Solar Cells [Silicon, Si] 14

15 Manufacture of Silicon Metal Electricity (coal) Carbon electrodes SiO 2, coke SiO 2 + 2C SiC + CO 2 Coal 2 SiC + SiO 2 3Si + 2 CO T > 2,000 C A typical charge consists of 450 Kg SiO 2 and 250 Kg coke An electric arc heats the system to ~ 2,350 C to melt the SiO 2 Energy consumption for > 99.99% Si is 20,000 GJ/t Steel and aluminum use 25 and 175 GJ/t 15

16 Nuclear Power Plant Grafenrheinfeld Nuclear Power Plant, Grafenrheinfeld, Bavaria, Germany 16

17 Alternative Energy and Transportation Lithium iron batteries not enough lithium Electricity must come from non-fossil fuel source 17 Can t be made without steel, aluminium or polymers

18 Public Transportation Planes, Trains and Ocean Vessels - Construction and power density requirement 18

19 Alternative Energy and Fertilizer Energy from nuclear fission, solar and wind do not produce sulfur or any commodities for fertilizer manufacture Production of bio-mass for transportation fuels or for chemicals (polymers) requires additional fertilizer Replacement of coal/petroleum coke for steel making by wood charcoal also requires additional fertilizer (as well as requiring a doubling of wood production) Can fertilizer needs be met without fossil fuel? 19

20 Can Phosphate Fertilizers Be Manufactured Without Sulfur? 1. Re-cycle of waste gypsum (CaSO 4 ) from previous phosphate production 2. Re-cycle of gypsum using H 2 S? 3. Manufacture of elemental phosphorus 4. Replacement of sulfuric acid by nitric acid 5. Phosphate re-cycle 20

21 Sulfuric Acid From Phosphogypsum Petroleum Phosphogypsum 2 [CaSO 4 ] 2 SO 2 + CO CaO coke [C] Phosphoric acid H 2 O [O 2 ] H 2 SO 4 SO 3 Calcium phosphate ore The reduction step occurs at around 1,000 C The clinker product [CaO + other minerals] could be used in cement or construction aggregates Large CO 2 emission Unlikely to be commercialized References: - G SR Gypsum Recycle Process, J Rossiter and D.K Kestner, Proceedings, Sulphur 1990, p Operation of a Sulphuric Acid Plant Based on Phosphogypsum, Z. Zhao and Y. Feng, Proceedings, Sulphur 1990, p

22 electrolysis H 2 O O 2 Replacement of Sulfur with Nitric Acid [No fossil fuel] N H 2 2 NH 3 2 HNO 3 + H 2 O Ca 3 (PO 4 ) HNO 3 3 Ca(NO 3 ) H 3 PO 4 Phosphate rock Fertilizer NH 3 Fertilizer Ca (NO 3 ) H 3 PO NH 3 CaHPO NH 4 NO (NH 4 ) 2 HPO 4 Electrolysis of H 2 O supplies H 2 and O 2 (electricity supply?) Nitric acid made by NH 3 oxidation (known technology, N 2 O emission) Digestion of phosphate rock provides two fertilizers 22

23 Phosphate Re-cycling From Sewage Sludge and Process Water Sewage Bio - solids [N, P, K, S] Water (NH 4+, PO 4 3- ) MgNH 4 PO 4 (Struvite) Direct land application CO 2 Mg (OH) 2 MgO H 2 O Slow release fertilizer Fuel oil ~ 700 C or CH 4 Mg CO 3 (Dolomite) CO 2 Phosphorus recycling comes with increased CO 2 emission 23

24 Practical and Feasible CO 2 Reduction Strategies These strategies are already in effect 1. Replacement of coal by natural gas for electricity production 2. Improved insulation of all buildings 3. Increased efficiency for agriculture (fertilizer use, eliminate food waste (30%), de-globalize) 4. Grow your own food, reduce animal protein intake (pork, poultry and eggs are good from an energy viewpoint) 5. Examine all industrial operations from an energy perspective [CO 2 emission] 24

25 Conclusion and Observations 1. Oil, gas and coal provide key commodities as well as energy. 2. Production of fertilizers, steel and cement requires gas, oil and coal. Use of wood charcoal for steel would require more than double the World s current wood production with a large increase in CO 2 emission. 3. Heavy oil and bitumen are more useful than low S, low residuum shale oil. 4. Low power density of wind/solar energy and materials considerations render a zero-carbon economy as highly improbable. 5. Long term, nuclear power generation should be developed further. Why? 5. Energy via electricity will be the basis of most new technology 25