Energy
Reserves and consumption
The initial source of most renewable and non reusable energy resources is solar energy.
Solar energy on Earth is very dilute, at approximately 1200 kcal/ hr m2.
The main non renewable sources based on historical solar energy are: Coal, oil, natural gas, peat, tar sands, shale and shale gas.
The non renewable sources not originating from solar energy are nuclear energy and geothermal energy.
The renewable sources are: hydroelectric.wind, direct solar energy, wood, other biomass, tides, waves, and sea water heat.
The amount of energy reserves depend on what price we are willing to pay. The more dilute the energy source – the higher its cost.
Estimates of energy reserves change every year and vary.
More than half of the energy consumption is by the more developed countries.Only 5-6% of energy consumption comes from renewable sources, mainly hydroelectric.
An approximately linear function can be made between energy consumption and GDP per capita.
The most important energy sources are crude oil, natural gas, and coal.
The price of crude oil (in current $) was around $3/bbl in 1972, and jumped to $15-17 in 1973, during the Yom Kippur war. It jumped again in 1977 with the rise of Humeini in Iran to $25. It rose to $40 in the early eighties and then dropped to $10 in the early nineties.
Later it bounced between $25 to $30 till 2004 when it jumped up to $45-80/bbl and occasionally reached over $100/bbl. However, the discovery of new large gas fields and the new methods to produce natural gas from shale fields have cause a reduction of oil price to the range of $45-60/bbl.
Uses
Industry
Home heating, cooling and cooking
Transportation
Electricity generation
Energy storage
Pumping water to ponds in high locations
Heating water or high thermal capacity materials
Dissociation of water to hydrogen and oxygen
Batteries
Chemical energy (Hydrides, water of crystallization)
Flywheel.
Energy transport
Moving of oil, gas and coal by boats, pipelines or railway.
High voltage electrical lines
Liquified natural gas by ships.
Methanol from natural gas
Emission of microwave energy from space (problematical)
Future trends
Prediction that OPEC will continue to hold the western world by the balls?
Clean nuclear energy?
Solar energy?
Biomass?
Energy from wastes?
In Israel
Consumption patterns have changed considerably by the proliferation of cars, air conditioners and the increased use of LPG. Increased use of coal and gas for electricity generation with great reduction in the use of heavy fuel oils.
Coal
Coal is an aromatics polymer composed mainly of C+H, and containing some O+N+S and inorganic minerals (ash) and water. It is thought that coal is the result of ancient plants and chemical processes over millions of years. Its main use these days is in the production
of electricity. The efficiency of the production of electricity from coal has risen from 18%
in 1937 to 39% in 1967 and to 45% in 1980.
The plans for the creation of large scale plants to produce synthesis gas (CO+H2) from coal in order to make petrochemicals and synthetic fuels have been frozen due to OPEC’s policy of reducing oil prices whenever fuel oil from coal plants are considered, and to the increased reserves of natural gas.
Oil
Crude oil is a mixture of many types of organic molecules with small amounts of nitrogen and sulfur. The composition of crude oil changes with location. It is
thought that crude oil was produced over millions of years from the remains of animals and plants.
Direct distillation of crude oil yields the following fractions:
LPG
Gasoline
Naphtha
Solvents
Kerosine and jet fuels
Light fuel oil (Soler) and Diesel fuel
Heavy fuel oil (Mazut)
Lubrication oils, asphalt and paraffin.
Upgrading of these fractions is by:
Thermal and catalytic cracking
Catalytic reforming
Alkylation
Isomerization
Polymerization
Sulfur recovery
Gas
Most natural gas was created over time by two mechanisms: biogenic and thermogenic. Biogenic gas is created by methanogenic organisms in marshes, bogs, landfills, and shallow sediments. Deeper in the earth, at greater temperature and pressure, thermogenic gas is created from buried organic material. Large deposits of methane, that occur as methane hydrids at deep ocean levels, will eventually be used
The discovery of new gas reserves, including in the sea next to Israel, the success of recovering natural gas, by fracking from shale deposits, and the attempts to reduce the production of CO2, have promoted a great increase in the production and use of natural gas in recent years.
Dilute sources
Shale may be considered as coal with 85% ash. The dilution demands higher costs of mining, transportation and environment recovery. It contains relatively high
concentrations of sulfur that have to be removed.
In Israel, we have large amounts of shale in concentrations of 10-15%. Mining is by removal of the earth layers above the shale.
Tar sands have a higher organics content than shale, but exist in only few locations in the world.
Peat includes high concentration of water, which costs energy for removal.
Solar energy is available only in day time, on cloudless days. The most economic uses of solar energy is for heating water for home use and in evaporating ponds (The Dead Sea plant is the prime example in Israel).
Recovering heat from the temperature differences in sea water or solar ponds have poor economics.
Geothermal energy is in use, but too much use may cause constriction of the upper earth layers and earthquakes.