Fuels water

FIG. 15-26 Fuel -water separator. Couttesy of Wamer-Lewis Co. Division, From Coif.)... 

The boiler designer must proportion heat-absorbing and heat-recovery surfaces in a way to make the best use of heat released by the fuel. Water walls, superheaters, and reheaters are exposed to convection and radiant heat, whereas convection heat transfer predominates in air preheaters and economizers. The relative amounts of these surfaces vary with the size and operating conditions of the boiler. 

This condition is of concern only when equipment operates in subzero ambient temperatures. Since diesel fuel extracted from crude oil contains a quantity of paraffin wax, at some low ambient temperatures this paraffin will precipitate and create wax crystals in the fuel. This can result in plugging of the fuel filters, resulting in a hard or no-start condition. Any moisture in the fuel can also form ice ciystals. Cloud point temperatures for various grades of diesel and other fuels should be at least 12°C (21.6°F) below the ambient temperature. In cases where cloud point becomes a problem, a fuel water separator and a heater are employed. 

It is therefore vital that detailed and accurate records are kept by the operating and engineering departments of the usage and consumption of fuel, water and other services in order that performance against budget can be properly measured and so that data are available for use in compiling future estimates. 

The oil in a refrigeration system should remain as clean as it is when it enters the compressor (unlike that of the automobile engine which is quickly contaminated by fuel, water, carbon and atmospheric dust). The condition of the compressor oil is therefore a direct indication of the physical and chemical cleanliness of the system. 

The cost of electricity, other fuels, water, spare parts and operating and maintenance labour represents the greater part of the owning costs of a refrigeration system. It is probable that a small extra expenditure on some items, especially heat exchangers, will reduce running costs. 

Chemical processes should be designed as part of a sustainable industrial activity that retains the capacity of ecosystems to support both life and industrial activity into the future. Sustainable industrial activity must meet the needs of the present, without compromising the needs of future generations. For chemical process design, this means that processes should use raw materials as efficiently as is economic and practicable, both to prevent the production of waste that can be environmentally harmful and to preserve the reserves of raw materials as much as possible. Processes should use as little energy as is economic and practicable, both to prevent the build-up of carbon dioxide in the atmosphere from burning fossil fuels and to preserve the reserves of fossil fuels. Water must also be consumed in... 

In a biodesulfurization process, there are actually three phases. For a liquid mixture containing the three phases - liquid fossil fuel, water, and the biocatalyst, more than one filter would be required. One filter will preferentially collect either the liquid fossil fuel or aqueous phase as the filtrate. The retentate will then flow to the second filter, which will collect the component not removed before. The remaining retentate, containing the biocatalyst, can then, preferably, be recycled. The process can be used to resolve an emulsion or microemulsion of the liquid fossil fuel and aqueous phase resulting from a... 

You may need to use bigger jets in your carburetor or an add-on water injection system to increase the amount of water to the cylinders for better performance. And a couple winds of copper tubing around the exhaust pipe from the fuel (water) pump would raise the water temperature for better vaporization too. 

The National Technical University of Athens (NTUA) works on hydrogen production from waste gases, production of hydrogen from solid fuels, water-gas-shift reaction catalysts, membrane separation, gasification of solid fuels, simulation of advanced power systems based on fuel cells, and hydrogen production and infrastructure. 

The original intent of this specification was to prevent the addition of high-octane, water-soluble components such as alcohol or diisopropyl ether to aviation gasoline. Present specifications require fuel, water and interface ratings by ASTM D-1094. 

Some common compounds which are approved for various fuel-water biocide applications include glutaraldehyde, methylene bis-thiocyanate and 2-methyl-4-... 

Effect of water pH on the fuel-water separation characteristics... 

Check fuel-water interface for microbial growth. 

Washing fuel with caustic will remove phenolic and acidic compounds from fuel water washing may also remove sediment from fuel... 

Treat system with a ferrous metal corrosion inhibitor Check for the presence of hydrocarbon-utilizing microbes or sulfate-reducing microbes treat fuel/water with a biocide... 

Evaluate fuel water bottoms for microorganisms treat with a biocide if a contamination problem is... 

Fuel-water emulsion technology has been utilized for several years to improve the combustion properties of heavy residual fuel oils. In the high-temperature combustion environment, water droplets that are finely dispersed in fuel begin to boil and explode into vapor within the fuel drops. As a result, a highly atomized... 

Spent fuels vary in microstructure, and phase and elemental distribution depending on the in-core reactor operating conditions and reactor history. The chemical stability of spent U oxide fuel is described by local pH and Eh conditions, redox being the most important parameter. However, the redox system will also evolve with time as various radionuclides decay and the proportion of oxidants and reductants generated at the fuel/water interface changes with the altering a-, (J-, y-radiation field and with the generation of other corrosion products that can act as... 

The time-dependent generation of radio-lytic oxidants and reductants at the spent fuel/water/canister interfaces ... 

The inherent radioactive characteristics of the spent nuclear fuel condition determine many of the key processes to be studied. Owing to its energy content, spent fuel relaxes by transferring alpha, beta, and gamma radiation to water when contacting it. This originates what is known as radiolysis reactions. The key processes occurring at the spent fuel water interface are depicted in Fig. 8. 

Depending on the water composition other radical species are formed, such as carbonate and chloride radicals. This imposes net oxidizing conditions at the water—fuel interface because the generated oxidants, molecular oxygen and hydrogen peroxide, predominate under a radiation, and other radical species like OH- or CQf- are more active than the generated reductants, mainly molecular hydrogen. This is why we propose that the spent fuel-water interface is a dynamic redox system, independently of the conditions imposed on the near field (Merino et al. 2001). 

Fig. 8. Key processes occurring at the spent fuel water interface (RN = radionuclides).

Polymers are attracting much attention as functional materials to construct photochemical solar energy conversion systems. Polymers and molecular assemblies are of great value for a conversion system to realize the necessary one-directional electron flow. Colloids of polymer supported metal and polynuclear metal complex are especially effective as catalysts for water photolysis. Fixation and reduction of N2 or C02 are also attractive in solar energy utilization, although they were not described in this article. If the reduction products such as alcohols, hydrocarbons, and ammonia are to be used as fuels, water should be the electron source for the economical reduction. This is why water photolysis has to be studied first. 

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