Fuels, alternative quality

Fuels, alternative -effect m air quality [ATMOSPHERIC MODELING] (Vol 3)... 

Meyer et cd. described the development of a multi-fuel processor by International Fuel Cells, LLC [627]. Methanol and gasohne (quality California reformulated gasoline grade II) were the major fuel alternatives. The technology chosen consisted of feed desulfurisation, autothermal reforming and catalytic carbon monoxide removal by two water-gas shift stages and two preferential oxidation reactors. The system had a power equivalent of 50 kW. However, performance data were only provided with respect to the autothermal reformer Desulfurisation proved to increase the reformer conversion up to 98%. No residual heavy hydrocarbons then remained in the product. The hot spot of the autothermal reformer approached 1000 °C. 

During long-term storage biodiesel can be easily subject to oxidation under ambient conditions due to the presence of double bonds in the chains of fatty compounds. The reaction of oxidation increases with the increasing of unsaturation level (polyunsaturated compounds are many times more reactive that monounsaturated ones). Some parameters such as acid value, peroxide value or kinematic viscosity increase when autoxidation occurs, thus the fuel s quality is affected. Degradation of the quality of this alternative fuel leads to an increase of deposits on injectors and pump parts and therefore an increase in pressure across filters. 

Chang, T. Y., Alternative transportation fuels and air quality. Environ. Sci. Technol. 25, 1190 (1991). 

In the United States, in particular, recent legislation has mandated sweeping improvements to urban air quality by limiting mobile source emissions and by promoting cleaner fuels. The new laws require commercial and government fleets to purchase a substantial number of vehicles powered by an alternative fuel, such as natural gas, propane, electricity, methanol or ethanol. However, natural gas is usually preferred because of its lower cost and lower emissions compared with the other available alternative gas or liquid fuels. Even when compared with electricity, it has been shown that the full fuel cycle emissions, including those from production, conversion, and transportation of the fuel, are lower for an NGV [2]. Natural gas vehicles offer other advantages as well. Where natural gas is abundantly available as a domestic resource, increased use... 

A lack of much-needed MU water softening, dealkalization, or similar external treatment capability is quite common in many small to midsized industrial facilities. It seldom produces a complete boiler failure or anything quite so dramatic, but it is nonetheless very costly in terms of additional fuel costs and maintenance. Personnel may learn to live with the resultant poor quality of FW for many years, accepting the position as normal until the facts are pointed out and alternative proposals are considered. 

These products can be fairly easily processed into high-quality diesel and jet fuel in theory, any source of carbon can be used to generate synthesis gas. These facts along with the growing need for petroleum alternatives have renewed interest in FT synthesis. During the twentieth century, the FT process was used to produce fuels from coal in large and costly reactors. Recently, this megasize approach has been applied to world-scale GTL plants in Qatar. However, to tap abundant biomass resources and stranded natural gas reserves, a smaller scale, yet economically viable, FT process is needed. 

The Fischer-Tropsch process has attracted renewed interest as a way to produce high quality, sulfur-free diesel fuel from natural gas and, possibly, an opportunity to utilize natural gas at remote oilfields. The process represents proven technology and is regarded as an alternative for when oil may no longer be widely available, and one has to resort to natural gas and coal. In a really futuristic scenario one may even contemplate the use of GO and H2 produced by photo-catalytic dissociation of GO2 and water. 

Most of the initial interest in alternative fuels started after the oil crisis in the 1970s. It has grown more recently by concerns about supply interruptions, high prices, air quality and greenhouse gases. 

There have also been revivals of the steam car. Robert McCulloch, the chain-saw millionaire, spent part of his fortune on a steam prototype, called the Paxton Phoenix, between 1951 and 1954. William Lear of Learjet fame, spent 15 million in 1969 on a turbine bus and a 250-horsepower turbine steam car. Both used quiet, efficient steam engines although the bus had reliability problems and poor gas mileage. Lear also tried to enter a steam car into the 1969 Indianapolis 500. The British firm of Austin-Healey was also working on a steam car in 1969. It had four-wheel drive. However, even prosperous entrepreneurs like McCulloch and Lear found that they lacked the means and support structure to successfully mass market a competitive car. Alternative power systems would have to wait until air-quality regulations resulted in some breakthroughs with hybrid and even fuel-cell cars. 

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