Fuel maximum electricity generation

Maximum Electricity Generation from Various Fuels... 

Other possible applications of smart elastomers are in the area of polymer engine which can produce maximum power density (4 W/g) and output both in terms of electrical and mechanical power without any noise. These features are superior compared to conventional electrical generator, fuel cell, and conventional IC engine. Many DoD applications (e.g., robotics, MAV) require both mechanical and electrical (hybrid) power, and polymer engine can eliminate entire transducer steps and can also save engine parts, weight, and is more efficient. 

Hyundai introduced its new i-Blue Fuel Cell Electric Vehicle. The i-Blue platform incorporates Hyundai s third-generation fuel cell technology and is powered by a 100-kW electrical engine and fuel cell stack. It is fueled with compressed hydrogen at 700 bar stored in a 115 liter tank. The i-Blue is capable of running more than 600-km per refueling stop and has a maximum speed of 165-km/h. 

A conventional power plant fired by fossil fuels converts the chemical energy of combustion of the fuel first to heat, which is used to raise steam, which in turn is used to drive the turbines that turn the electrical generators. Quite apart from the mechanical and thermal energy losses in this sequence, the maximum thermodynamic efficiency e for any heat engine is limited by the relative temperatures of the heat source (That) and heat sink (Tcoid) ... 

The calculated values of exergy ratios for various primary and secondary sources are shown in Table 1. It 1s to be noted that all the fossil fuel sources are inherently of very high quality. The value of aE greater than unity for coal stems from the fact that a reversible oxidation of carbon at ambient temperature has a negative TQ S and results in production of more work than the enthalpy of combustion, with an associated absorption of heat from the environment. In spite of these high values of < r, when fossil fuels are combusted, say for electrical generation, the maximum temperature is limited not by thermodynamic considerations but by materials constraints. The effective < under this limitation is restricted to values below 0.65. t... 

Oil-burning electric generating plants can also produce comparable amounts of SOg because some fuel oils can contain up to 4% sulfur. The sulfur in the oil is in the form of compounds in which sulfur atoms are bound to carbon and hydrogen atoms. Gasoline contains relatively low concentrations of sulfur-containing compounds. Even so, the EPA has mandated that the maximum concentration of sulfur-containing compounds be reduced from 120 ppm in 2004 to 90 ppm in 2005 and to 30 ppm by 2006. Further mandated reductions may be expected. 

Equation 1.3 indicates that, for an electrochemical reaction, part of the reaction energy (AH) is used to generate electrical energy (AG), and the other part is used to produce heat (TAS). In a fuel cell system, the most useful energy is electrical energy, while the heat produced is sometimes not desired. Therefore, electrical efficiency (or the reversible or thermod5mamic efficiency), can be defined as the ratio of the maximum electrical energy from the cell reaction to the reaction enthalpy. This represents the theoretical upper limit for fuel cell electrical efficiency. 

Since the direct electron transfer via outer membrane cytochromes requires the physical contact of the bacterial cell to the fuel cell anode, only bacteria in the first monolayer at the anode surface are electrochemically active and responsible for electricity generation. Consequently, the MFC performance is limited by the maximum cell density in this bacterial monolayer. For example, maximum current densities as low as 0.6 and 6.5 pA cm were achieved for MFCs based on pure Shewanella putrefaciens [13] and Geobacter sulfurreducens [21], respectively. 

Despite the fact that OTEC systems have no fuel costs and can produce useful by-products, the initial high cost of building such power plants (up to 5,000 per kilowatt) currently makes OTEC generated electricity up to five times more expensive than conventional alternatives. As such, at the present time OTEC systems are largely restricted to experimental and demonstration units. One of the major facilities for OTEC research is the Natural Energy Laboratory of Hawaii Authority at Keahole Point on the island of Hawaii. An experimental OTEC facility located there has had a maximum net power production of 100 kilowatts, at the same time producing 5 gallons per minute of desalinated water. 

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