Fuel Treatment Formulations

This chapter discusses the problems associated with each of the zones, the types of fuel treatments available, and benefits to be gained, and provides an outline on the type of formulations employed. 

Fuel treatments have been used for very many years as an aid to improving the combustion efficiency process. Old formulations often used saw dust, wood flour, common salt, zinc sludge, ground oyster shell, and similar crude ingredients, but could still provide a dramatic effect when thrown into a fire. The metallic salts present (sodium in salt, zinc in sludge, and calcium in shell) acted as catalysts that dramatically lowered the ignition temperature of soot deposits from around 1100 °F/590 °C to only 600 °C/315 °C the fire burned vigorously and the soot disappeared. 

The primary ingredients of most fuel additive formulations almost always include metals such as iron, copper, manganese, magnesium, or cerium. Depending on the form of the treatment, these metals can be present in several forms, including ... 

Apart from metals, ammonium chloride, amine, and diamine salts, and various organic polymeric dispersants and surfactants are employed in fuel treatment additive formulations. 

There are hundreds of fuel treatments and additive formulations in commercial use today. Following are five formulations, typical of the types of products commonly available. 

Clinker treatments are additives designed to reduce the amount of clinkering formations that takes place in boilers fired by bark, bagasse, and similar low-calorific-value fuels. These fuels can give rise to considerable amounts of noncombustible deposits that must be continuously or regularly removed from the furnace area. Clinker treatments are formulated for use with various types of furnace, including slant, pin hole, and chain grate furnaces. 

This formulation is proposed as a complete treatment, comprising powdered and crystalline combustion catalysts and slag modifiers. It is designed for pulverized fuel (PF), brown coal, lignite, peat moss, and bark, and for application with cyclone burners, chain grates, underfed, and spreader stokers. 

This formulation is designed as a complete treatment, providing improved atomization and combustion, sludge dispersancy, demulsifi-cation of water from oil, prevention of bacterial slimes at the water-oil interface, reduced cold-end corrosion, and less fuel system deposits. 

Certain catalyst manufacturers claims to have optimized the preparation (CoMo catalysts), the formulation or the promotion (aromatic saturation) of their catalysts to achieve an appropriate balance of the hydrogenation function to desulfurize the sterically hindered compounds and yield the 15 ppm S fuel. However, the actual trend is to use NiMo catalyst for the treatment of the more refractory compounds, below 200 ppm S [22],... 

The substantial effect of secondary breakup of droplets on the final droplet size distributions in sprays has been reported by many researchers, particularly for overheated hydrocarbon fuel sprays. 557 A quantitative analysis of the secondary breakup process must deal with the aerodynamic effects caused by the flow around each individual, moving droplet, introducing additional difficulty in theoretical treatment. Aslanov and Shamshev 557 presented an elementary mathematical model of this highly transient phenomenon, formulated on the basis of the theory of hydrodynamic instability on the droplet-gas interface. The model and approach may be used to make estimations of the range of droplet sizes and to calculate droplet breakup in high-speed flows behind shock waves, characteristic of detonation spray processes. 

To do this, the paper first explained the operation of existing particulate control devices, notably the electrostatic precipitator (ESP). It described how particulate capturability can be improved by chemical treatment and then illustrated how proprietary formulation has led to the treatment of a wide variety of fuels in both cold and hot side ESP units. Evidence was also presented showing fine particulate emissions, i.e., those implicated in health effects, could be significantly reduced. A description was made of the specific marketing problems that had to be solved when a chemical company sought to develop an industrial market where the customer has little or no chemical capability. 

Their primary use has been as fuels in pyrot delay formulations (see under Delays and Fuzes in Vol 8, P512-R to P515-L Table 9), where they replaced the earlier use of. separate powders of Zr and Ni. Because of changes in burning rate on storage and at varying operational temps exhibited by delay compns contg individual Zr and Ni powders, and because treatment to resist corrosion of both the Zr and Ni did not alleviate the difficulties, their use was discontinued, and attention was focused on the alloys of Zr and Ni as a potential fuel. The alloys were less flammable and hazardous to use than fme Zr pdr, and eliminated the need for catalytic Ni pdr which must be manufd under very carefully controlled conditions (Ref 3)... 

Polymers are probably best known for their use as bulk materials, as discussed in the previous section. However, they also play an important role in the control of solution and dispersion rheology. This apphcation includes fields as diverse as fuels, lubricants, water treatment chemicals, foodstuffs, and cosmetic formulations. In these areas polymers affect the flow behavior, and thereby the performance, of a fluid during and after application. When one attempts to dissolve a polymer in solvents selected at random, many, per-... 

---