There will be many such perpetual motion systems and the public should be made aware of the pitfalls. In the early days of railroads, rails were welded using the molten iron produced by this reaction.
Introduction
The comparison of global energy consumption per capita and its patterns in the main regions is presented in Fig. 1.4. According to the Oil & Gas Journal, 56% of the world's proven oil reserves are located in the Middle East.
Renewable Energy Sources
If the average temperature of the oceans were to rise by 1C, the expansion would raise sea levels by about 60 cm (assuming the glacial ice does not melt). The oceans and forests (biomass growth) consume most of the CO2, and it is possible that these sinks for CO2 become saturated or that new sinks become available on the other hand.
Geothermal
Estimates of geothermal energy currently being used and converted into electrical power is approximately 2103MW. The increased use of geothermal energy can help save much of our energy needs and will reduce the rate of increase of CO2 in the atmosphere.
Tidal Power
It has been estimated that the geothermal energy in the outer 10 km of the Earth is approximately 1023 kJ or about 2,000 times the thermal energy of the world's total coal resources.
Solar Energy
Plants that produce hydrocarbons directly are known - the best example is the rubber tree that produces an aqueous emulsion of latex - an isoprene polymer (mol. Energy to biomass energy ratio, i.e. energy yield/energy consumed for growth and processing, it is variable and usually between 3 and 10.
Photovoltaic Cells
Grain, sugarcane, and other carbohydrate-containing crops can be harvested for starch and sugar, which can be fermented into ethyl alcohol. Thus, an energy farm where conventional crops can be used as fuel is clearly a requirement if stored solar energy is to replace dwindling fossil fuels.
Photogalvanic Cells
A 6 9-m2 array of solar cells operating at 10% efficiency with a peak output capacity of 5 kW at noon would provide an average of 1 kW over the year—more than the electrical energy requirements of an average home used as electrical storage to provide energy for cloudy and rainy days and during the night.
Wind Energy
Hydropower
Ocean Thermal
To maintain the density gradient, salt-free water is added to the surface and salt-enriched water is introduced into the bottom layer. The problems associated with solar ponds are: (1) Surface mixing due to winds tending to create convection zones near the surface.
Wave Energy
Osmotic Power
Kitasei S, Mastny L (2010) Driving a low-carbon economy: past and future roles of renewable energy and natural gas. Weaver, David Jeffrey, Rick Gore (1981) Energy—A special report in the public interest, National Geographic, Deluxe Edition.
Introduction
The old steam engines, which consumed a ton of coal for every four miles of heavy cargo hauled, consumed a quarter of coal production (125 million tons). China consumed 2.7 billion tons of coal in 2008 or 43% of the world's total and 2.5 times more than the second largest consumer, the US.
Wood and Charcoal
Peat
Coal
Analysis of Coal
If the sample of coal is first freed of volatile matter, then the weight loss represents the solid carbon in the coal. This is often referred to as the coal's calorific value or heat content.
ASTM Classification
The choice of components depends on the carbon and impurities in the ash. The composition of the fly ash usually differs from the bottom ash due to thermal fractionation of the oxides.
Coal and Its Environment
This is illustrated in Table 2.4, where bottom ash composition is compared with different fractions of fly ash, which is classified into five groups: a) alkali and alkaline earth metals (b) refractory metals. Thus, the concentration of 226Ra is two orders of magnitude lower than the MPC, but since fly ash contains other radionuclides (230U, 210Pb, etc.), the long-term effects on those living near or downwind of coal-fired power plants must be carefully monitored.
Fluidized Bed Combustion
Coke
What would be the composition of the ash if a mixture of the coals was burned A:B of 2:1. Explain why the calorific value of the volatile part of a coal (per unit mass) is usually greater than the solid carbon of the coal.
Introduction
Early History
The height (or area) of the peak is proportional to its concentration in the injected sample. The presence and ratio of the two branched hydrocarbons, pristanetetramethylpentadecane) and phytanetetramethylhexadecane), can be used to identify the source of the oil.
World Production of Crude Oil
Many oil fields in northern Siberia are not connected to pipelines and therefore await further development. Another source of oil is oil shale and tar sands, which require special processing to extract oil.
Crude Oil Processing
For in situ mining, the steam can be injected into the boreholes to heat the sand and make the oil flow. Other processes involve controlled ignition of the tar sands and air pressure to propel the liberated oil to the production wells.
Petroleum Products
The stability of the fuel has improved, and specific corrosion inhibitors, antioxidants and antistatic additives have been included in formulations. Natural bitumen is found in the US, Europe and other parts of the world.
Synthetic Oil
The reaction CO + H2O!H2+ CO2 is called the water shift reaction and is often used in the Fischer-Tropsch process. Why is directly liquefying coal with hydrogen into oil a more sensible process than producing crude oil through the Fischer-Tropsch synthetic fuel production process?
Introduction
Diesel Engine
In the compression stage, the air is compressed to about 1/20 of its initial volume, which means that the engine has a compression ratio (CR) of at least 20, and this high ratio represents the high efficiency of the engine. Direct injection engines are generally used in larger, lower speed engines with cylinder bores greater than 12 cm in diameter.
Diesel Fuel
The addition of barium compounds to diesel fuel has been proven to reduce the emission of black smoke. The addition of 2 wt% of a 5 M NH4NO3 solution in water can increase the CN of diesel fuel from 39 to 42.
Ignition Temperature, Flash Point, Fire Point, and Smoke Point
The methyl esters are usually straight chain hydrocarbons and have relatively high cetane values as shown in Table 4.3.
The Spark Ignition Internal Combustion Engine
Gasoline Fuel
This end gas is heated by compression, by the combustion taking place, and by the approaching flame front. The lead oxide aerosol that forms in the combustion is a free radical trap and prevents the chain reaction from branching and progressing to explosive rates.
Grading Gasoline
Due to the toxic properties of lead and its compounds, some countries have replaced lead with other octane boosters. Time increases from left to right.) (a) Normal process - flame moves smoothly from spark to final gas.
Introduction
The search for alternative fuels has been stimulated by environmental concerns regarding emissions in the exhaust gases of gasoline and diesel engines. However, this means that the source of electricity used to charge the batteries is environmentally friendly.
Propane
The cost of propane is typically less than gasoline on a volume basis, and the main users are fleet operators such as taxis, delivery trucks, and vans (see Fig. 5.2). The use of propane in Canada and the US has failed due to the cost of conversion requiring large storage tanks, fewer gas stations than for gasoline, and restrictions on underground parking.
Methanol
Another problem is corrosion due to the acid (formic acid) formed by the oxidation of methanol, and all fuel and engine components must be carefully selected. A major problem in the use of gasohol is in the construction materials of the fuel system.
Ethanol
This value can be calculated from the adiabatic compression of a gas (mostly air) from T1=350 K and assuming CR=10. The standard heat of formation is DHfo. a) Calculate the value of the equilibrium constant Kp for the reaction N2+ O2⇄2NO.
Introduction
Natural Gas
This natural gas hydrate is present on the ocean floor, in the sediment beneath the seabed, and in the cold permafrost of the Arctic. Natural gas is usually saturated with water as it exits the well, and as a result, gas hydrates can form in the pipeline, restricting gas flow.
Natural Gas Uses
The estimated amounts of CH4 bound as hydrate in permafrost and deep seawater are 10 teratons or about 53% of the Earth's total combustible carbon. To destroy such plugs in the cold Siberian pipeline, large quantities of methanol are introduced at an approximate rate of 1 kg/1,000 m3 of gas.
Natural Gas as a Fuel
Other Carbon-Based Fuel Gases
Explosion Limits
Hydrogen
It is highly explosive and with the destruction of the Hindenburg in 1937, commercial travel in H2-filled shipments ended. However, it should be pointed out that the Hindenburg disaster resulted in the death of only 36 people, most due to burning diesel from the engines and by jumping to the ground.
Methods of Preparation of H 2
- Electrolysis
- Thermal Methods
- Natural Gas
- Thermal-Nuclear-Electrical
- Photoelectrolysis
The corrosive nature of some products implies rather complicated precautions in construction and design. The given efficiency represents the thermal efficiency of the sum of the steps, as well as the Carnot (reversible) efficiency.
Transportation and Storage of H 2
When cooled to room temperature, the gas remains in the cage even when the pressure is released. In the case of methane encapsulation, it has been shown that up to about 7 wt% CH4 can be stored for 5 months in an unaltered type 3A molecular sieve without appreciable loss.
Safety
It should be noted that the density of hydrogen in the metal hydride is similar to that of liquid H2, which implies that the hydrogen in the metal is in atomic form. A more recent determination of H2O2 formed in the exhaust of a hydrogen-fueled engine showed that very little H2O2 is present and that the high levels previously reported were due to the method of analysis which was affected by exhaust NOxine.
Helium
The activated metal can be reacted with water to produce hydrogen and the metal oxide, i.e. the reverse of the above reaction. The engine's efficiency is assumed to be thermally equivalent to gasoline, which uses 10 L/100 km.
Introduction
Basis Theory of Nuclear Energy
The mass of the components of the nucleus is always (except H) greater than the actual mass of the nucleus. The difference (a mass defect) represents the binding energy of the nucleus, DE, and represents the energy required to break a nucleus into its individual components (Fig.7.2).
Nuclear Model and Nuclear Reactions
The specific nuclear binding energy is DEB/A and represents the average binding energy per nucleon.
Radioactive Decay Rates
In 1950, a sample of linen in which some of the Dead Sea Scrolls were wrapped was burned in CO2 and analyzed for 14C. Radiation is measured by different methods which depend on the type of radiation - a, b, andg - and the activity of the source.
Radioactivity Units
Nuclear Reactors
The stabilization of the fragments and the radiation results in the thermal energy produced by the chain reaction. Fig.7.5 Similar to the boiler in a coal, oil or gas fired oil power station, a nuclear reactor produces steam to drive a turbine that turns an electrical generator. .Water is pumped through the core to transfer heat to the steam generator. The coolant water is kept under pressure in the core to prevent boiling and transfers heat to the water in the steam generator to make the steam. (c) The HTGR shown here is a type of reactor fed by uranium carbide particles distributed in the graphite core. Helium gas is used as a coolant to transfer the heat from the core to the generator. (d) In an LMFBR In the primary loop, molten sodium is pumped through the reactor core containing the fuel. This sodium collects the heat and transfers it to a secondary sodium loop in the heat exchanger, from where it is fed to the steam generator. In addition to producing electricity, this reactor also produces more fissile material than it consumes, which is why it is called a "breeder reactor". In the reactor, uranium-238 is converted into fission plutonium-239, which is periodically extracted and processed into new fuel.
The Hazards of Nuclear Energy
It is possible to predict that there will be 500 deaths in the US due to car accidents (50 in Canada) during the Labor Day weekend holiday in September. Edward Teller—the father of the H-bomb—once pointed out that solar energy is not without its dangers because the ladder, which would be needed to clean solar cells on the roof of our houses, causes more accidents in the house than any other device.
Nuclear Waste
Some alternative waste disposal proposals include the following: (a) space option, (b) Antarctic ice shelf, (c) ocean disposal, (d) ocean burial, and (e) nuclear transformation. a) A soft landing approach for storing nuclear waste on the Moon has been evaluated, but until such flights become routine it must be considered too risky and expensive (launch costs are currently about US$ per ton for low Earth orbit). This is being actively studied and assessed for environmental impact. e) The conversion of radioactive nuclei through nuclear reactions and conversion into stable nuclei is possible.
Nuclear Fusion
Evidence of battery leakage has been obtained and long-term storage is not feasible for high-level waste. Recent experiments on the electrolysis of LiOD to D2O at a palladium cathode have been claimed to result in "cold" fusion.
Summary
Phylippovsky VI, Roussak OV (1997) Use of natural inorganic sorbents to increase the safety of long-term storage of radioactive waste.
An Introduction to Tribology
Gaseous Lubricants
For hydrodynamic conditions, the minimum film thickness for a gas thrust bearing is given by the relation 8.3) where ¼ viscosity, V¼ means the running speed, l¼ the length of the shoe in the direction of rotation and Pav. The mean free path of a gas is the average distance a molecule moves between collisions and is given by.
Liquid Lubricants
- Journal Bearings
- Thrust Bearings
- Slider Bearings
- Ball Bearings
Z¼the viscosity of the lubricant, N¼the speed of the shaft, and P¼the pressure or load divided by the projected area. An important property of EHL is the specific film thickness (l) which is the ratio of the film thickness (h) to the composite roughness (s) of the two surfaces, ie.
Extreme Pressure Lubrication
Wear
Oil Additives
These tend to increase the viscosity of the oil more at high temperatures than at low temperatures. When oxidized, the oil can form peroxides that eventually decompose into acids that cause corrosion of the metal components.
Synthetic Lubricants
Foam and scum in the oil is caused by air becoming trapped while pumping and moving oil through various parts of the engine. Foam reduces the effectiveness of the lubricant and thus can result in increased friction and wear.
Solid Lubricants
Teflon is a thermosetting plastic, but cannot be used as such because it is too viscous above the glass transition temperature of 325 C. Another disadvantage of Teflon is that it is a poor conductor of heat and has a high coefficient of expansion.
Greases
Introduction
Ionics
An alloy of tin and lead is deposited from a solution of Sn(NO3)2 and Pb(NO3)2. What is the percentage of tin in the alloy if 35.00 g of alloy is deposited when 3.00 amp current is passed through the solution for 4.00 hours.
Electrolysis and Electrodeposition of Metals
The overvoltage encountered in the electrodeposition of a metal can be accompanied by various steps by which the metal in solution, for example, Cu2þ, becomes atomized in a copper lattice. The sequence of relative importance is 2 >3 >4 >l>5 with step 2 being the slowest step or rate controlling process.
Electrochemical Machining
- The Cathode
- The Electrolyte
The purpose of the electrolyte is to provide a conductive medium and at the same time it must not corrode the cathode tool. By pulsing the direct current, it is possible to reduce the required electrolyte flow rate.
Electrodics
2The standard hydrogen electrode potential (SHE) is defined as zero at all temperatures for [H+]aq=1 M and P (H2)=1 atm. The cell will continue to develop the potential until the Cu2þ concentration in both half cells becomes equal.
Batteries and Cells
- Primary Batteries
- Secondary Batteries
However, the cost of the cell is about twice that of the zinc-carbon cell. In this property as well as others, the nickel-alkaline battery is superior to - although about three times more expensive than - the lead-acid battery.
Fuel Cells
The hydrogen-oxygen fuel cell device developed by Bacon with gas-diffusion electrodes is shown in Figure 9.12. A fuel cell-powered economy car, while a distinct possibility, is not expected in the near future.
Hybrid Cells
Today, fuel cells are still in the development phase and much work is needed before an efficient, economical fuel cell is produced. The aluminum-air battery has recently received some attention as a result of work done at Lawrence Livermore National Laboratory.
Electric Vehicle
Explain why the capacity of the lead-acid battery decreases so rapidly with a decrease in temperature. Make the following assumptions: (1) heats of combustion of gasoline and hydrogen are given in Table 6.8; (2) the car has the same efficiency as the new generation of cars, namely 14 km/L of gasoline; and (3) the efficiency of the hydrogen-powered vehicle is related to its comparable heat of combustion to the gasoline efficiency.
Introduction
Factors Affecting the Rate of Corrosion
Another factor that controls the corrosion rate is the relative volume of the corrosion product (oxide) to the metal as well as the porosity of the oxide layer. The large copper surface area results in a low O2 overvoltage, allowing the corrosion to proceed at a rate controlled by O2 diffusion.
Types of Corrosion
- Uniform Corrosion
- Bimetallic Corrosion
- Crevice Corrosion
- Pitting Corrosion
- Grain Boundary Corrosion
- Layer Corrosion
- Stress Corrosion Cracking
The corrosion rate is partly determined by the difference in the standard cell potentials of the two metals in contact (see Table 9.4). The mechanism of iron sinking under a water droplet is shown in Fig. 10.2, and just like in a CC, a differential concentration of oxygen in the droplet creates a concentration cell.
