Fuel processing problems

A variety of non-hydrocarbon species is found in crude oil. These compounds are found in all molecular weight ranges of crude oil components, but seem to concentrate in the heavier distillate and residual oil fractions. The effect of these materials on processing equipment, refining catalysts, and finished product quality can be dramatic. Corrosion, catalyst poisoning, and fuel stability problems can all be due to the effect of these nonhydrocarbon species. 

A wide range of fuel performance problems can often be solved by the use of chemical additives. Although in some circumstances the additives used may be no substitute for refining processes such as hydrotreating, caustic washing, or distillation, they can provide an alternative to further processing. 

The continuous change taking place within the present-day petroleum refining and alternative fuel industries has not diminished the need to solve fuel-related problems as they develop. Even after fuel is processed, problems in handling, transportation,... 

The number and variety of fuel combustion problems that are still unsolved suggest that many different fuel additives may still come into use. Petroleum refiners will thereby be able to continue to employ a two-pronged attack when improving their products first, the development of improved refining processes, and second, the use of chemical additives. 

The second dilemma for a synthetic fuels process developer is related to "selling" the process. To be put to commercial use, the process under development must not only produce the products required, but must be shown to do so at costs that are competitive with other supplemental sources. The problem is to obtain economic analysis information on a consistent basis. A review of published economics indicates that it would probably be difficult to do this from papers presented at public meetings. Thus, for choosing a developing process to be used - or even to be supported... 

In the works devoted to study and development of MEISs numerous examples on their application to the analysis of various problems were certainly presented. They are formation of harmful substances during fuel combustion and cleaning of combustion products from these components, fuel processing, atmospheric pollution with anthropogenic emissions, stationary and nonstationary flow distribution in hydraulic systems, etc. These examples should illustrate practical efficiency of MEISs, their capabilities for revealing specific features of the modeled process and determining directions of its improvement. 

A block diagram for a gas processing plant is shown below. The purpose of this process is to recover ethane and propane (+ butane) from a natural-gas stream because these components have more value as chemicals than as fuel. This problem is based upon the 1987 AIChE Student Contest Problem. 

The development of commercially viable plastic pyrolysis processes has up to now been hindered by the need to engineer around various process problems such as reactor fouling by carbon deposits, poor heat transfer of molten plastics, the requirement for integrated fractionation of products, separation of water and suspended carbon from the liquid fuels and integrated desulphurization. 

In this paper we will concentrate on the problems associated with a market-related fuels-processing facility—specifically one which would serve the U.S. East Coast. Planning such a facility involves the several fundamental questions considered below ... 

Finally, the fact that these organoarsonic acids are released upon oil shale pyrolysis has important implications in the various synthetic fuel processes, where the role of organometallic compounds in poisoning process catalysts and contributing to environmental problems, is paramount. (32,33)... 

Moreover, the presence of 1% CO in the hydrogen causes major problems in Pt-based fuel cells because Pt is poisoned by CO at the operating temperatures of the fuel cell. Current commercial fuel processing systems rely on a subsequent CO clean-up system based on the reaction ... 

The shale oil which remained after the processing run was burned as boiler fuel. No problems developed over the 1 month combustion period. 

Proprietary components were designed and developed to achieve a technically superior fuel processor by solving specific problems related to several of the fundamental processes associated with fuel processing. These components will comprise a more efficient system that is sulfur tolerant and produces pure hydrogen while remaining compact and lightweight. 

The mitigation of fouling in combustion equipment therefore, is of primary concern for designers and operators with special reference to the fuel. The problem of fouling and slagging is an important consideration in the choice of combustion process and for convenience the various fuels will be discussed separately as they generally generate different problems. 

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