Fuel wastage

Figure 10.18 Effect of fuel type on fuel wastage...

In the preceding paragraphs we discussed how operation without enough combustion air on the wrong side of the point of absolute combustion leads to inefficient combustion of fuel. Apart from the fuel wastage, there is another important disturbing and frequently... 

It is important to monitor the concentration of methane using a sensor as the fuel crossover may occur. The problem of fuel crossover is severe for the PEM direct methanol fuel cell. Methanol dissolves quickly in water and reaches the cathode. The presence of platinum catalyst on the cathode will oxidise the fuel, though not as effectively as the anode catalysts. Hence, fuel wastage will occur at the cathode reducing the cell voltage. This phenomenon yields mixed potential and the fuel utilisation coefficient //f is defined as... 

Many of the fission products formed in a nuclear reactor are themselves strong neutron absorbers (i.e. poisons ) and so will stop the chain reaction before all the (and Pu which has also been formed) has been consumed. If this wastage is to be avoided the irradiated fuel elements must be removed periodically and the fission products separated from the remaining uranium and the plutonijjm. Such reprocessing is of course inherent in the operation of fast-breeder reactors, but whether or not it is used for thermal reactors depends on economic and political factors. Reprocessing is currently undertaken in the UK, France and Russia but is not considered to be economic in the USA. 

Traps that are corroded and leak steam and water waste heat energy. This wastage can add up to a significant extra requirement for primary fuel. 

Corrosion anywhere within the steam-water circuits results in metal wastage and possible equipment failure. And if the boiler plant is not operated correctly or if the water chemistry is not maintained within certain control parameters, the generated steam may contain contaminants in a cause-and-effect process that ultimately affects the utilization of the steam, reducing quality in a number of areas, and increasing fuel, manufacturing, or maintenance costs. 

High velocity steam or particles striking a metal surface and causing metal wastage by erosion. Also refers to unbumed fuel oil striking a surface and resulting in the formation of carbon deposits and smoke. 

The wastage of fuel caused by an inadequate supply of air, resulting in the formation of soot and smoke, and unbumt particles remaining in the ash. 

In the collective European imagination and especially that of the French, plastic materials today symbolize pollution, wastage of fossil fuels and toxicity. In reality, they contribute to sustainable development in various capacities. To better understand the difference between a dark vision and positive facts, we must bear in mind the view of the future such as that drawn by scientists, statisticians and futurists. 

Not only have the body s fat reserves been exhausted, but there is wastage of muscle as well, and as the condition progresses there is loss of protein from the heart, liver and kidneys, although as far as possible essential tissue proteins are protected. As discussed in section 9.2.3.3, protein synthesis is energy expensive, and in marasmus there is a considerable reduction in the rate of protein synthesis, although catabolism continues at the normal rate (section 9.1.1). The amino acids released by the catalysis of tissue proteins are used as a source of metabolic fuel and as substrates for gluconeogenesis to maintain a supply of glucose for the brain and red blood cells (section 5.7). 

The factor which limits the thermal performance of IFR fuel is the potential for clad wastage from interaction with fuel over an extended period at extreme conditions in a slowly... 

The rate of platinum consumption has been found to accelerate in the presence of AC current ripples. Most wastage has been observed to occur with AC frequencies of less than 50 Hz. The repeated oxidation/reduction processes result in the formation of a brownish layer of platinum oxide. To avoid the occurrence of this phenomenon, a single- or a three-phase full-wave rectification is recommended. The consumption rate of platinized anodes is also adversely affected by the presence of organic impurities such as sugar and diesel fuel. 

The fuel crossover losses are due to the wastage of fuel passing through the electrolyte. Fuel crossover losses are prominent in the fuel cell operation at low temperatures. The activation losses are due to the slow reaction kinetics on the surface of the electrodes. Ohmic losses are due to the resistance offered to the flow of electrons and ions through electrodes and electrolytes, respectively. The concentration losses are due to the change in concentration of the reactants at the surface of electrodes. 

Another problem was that to keep neutron wastage as low as possible, the core should be as compact as possible, which meant that there would be no space to spare for control rods. Instead, the proposal was that certain fuel rods could be withdrawn from the reactor to shut it down. 

Plasties materials are dumped however, with the increasing cost of land, this is becoming uneconomical. In addition to this, there is total wastage of the material and energy (assuming that the polymer could be burnt as fuel) [29,30]. 

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