Fuel-water emulsions

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... 

NOTE Where the fuel tank contains oily water emulsions, sludge, and particulates, the effectiveness of any fuel treatment is directly related to the ability of the additive to penetrate and attack the sludge or emulsion mass. Simply feeding the treatment to the tank does not work. Typically, some form of power-injection equipment is employed to inject the chemical under 100 to 200 psig pressure. Agitation of the entire tank contents also is required and can often be carried out using the same equipment. 

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... 

During the refining and processing of fuel, corrosion inhibitors, antifoulants, filmers, neutralizers, and other organic compounds may carry over into a finished product. These polar organics may attract and interact with water to tightly bind it into the fuel as an emulsion. The result is usually a cloudy, hazy fuel. These emulsions are often quite difficult to break. If the water present contains caustic, organic salts, or corrosion products, the emulsion may be quite stable. 

Diesel-water emulsions are being studied extensively worldwide because of the impact these fuels have on reducing engine exhaust emissions, especially NOx and particulates. Although formulations vary, a typical diesel-water emulsion will contain approximately 80% to 90% diesel fuel, 10% to 15% water, and 1% to 5% of an emulsification additive mixture. The resulting fuel blend is transparent in appearance and has the typical appearance of diesel fuel. 

Diesel-water emulsions are not approved for shipment by finished product pipeline companies. Consequently, the emulsion must be made on-site or near the point of sale. Other issues currently being resolved deal with improving the cold-temperature handling properties of the high-water-content fuel and improving the long-term storage stability of fuel blends... 

Diffusion Flame The flame produced by the spontaneous mixture of fuel vapors or gases and air. Dispersants These are chemicals which reduce the surface tension between oil and water, thus facilitating he breakup and dispersal of an oil slick in the form of an oil-in-water emulsion. Dispersing Agent An adjuvant diat reduces the attraction between particles. 

Water Emulsion Fuels, Propellants and Propulsion Systems. See under Liquid Propellants in Vol 7, L34-R to L44-R under Propellants, Solid in Vol 8, P430-L to P439-L and the following AddnlRefs ... 

In the last year a new formulation of aminocarb has appeared on the insecticide market. It is finely ground aminocarb suspended in an oil and it has the advantage that it can be tank mixed to give either an oil or a water suspension. Studies (10) show that, like the oil solution, this product has a half life in the same range (3.2 to 6.0 days). There was an indication of a variation in the initial rate of loss due to the physical characteristics of the water emulsion spray (in a series of repeat studies the evaporation rate was not constant). The presence of the emulsifier inhibited evaporation resulting in a higher initial foliar deposit than with the oil base spray. The occurence of the lower rate of deposit of the oil spray can be attributed to the particular oil used in the Canadian budworm sprays. To meet the concerns of the health authorities the standard No. 2 and No. 4 fuel oils which had been used are now prohibited. The accepted product, known as Insecticide Diluent 585 is volatile with an evaporation rate approaching that of water. 

The intimate mixing of oxidizer and fuel in emulsions give these explosives much higher detonation velocities when compared to ANFO. For example, in 150 mm diameter PVC ANFO has a velocity of about 4000 m/sec, and a sensitized emulsion would have a velocity closer to 6000 m/sec at a density of 1.20-1.25 g/cc. Also, the layer of oil surrounding each oxidizer solution droplet protects the emulsion from extraneous water intrusion and subsequent deterioration of the explosive. Many studies have shown that when mining operations use emulsion explosives rather than ANFO, which has basically no water resistance, the amount of nitrate salts in mine ground water is reduced considerably. This can be a very important factor in today s environmentally conscious mining and explosives industry. 

The effect of entibititic residues m dairy products Photocyanation of aromatic compounds Hydrocarbon-water emulsions as fuels... 

The use of oil-in-water emulsions to reduce the viscosity of heavy crude oils and bitumens and thus permit their transportation by conventional pipeline has been under development by Canadian Occidental since the fall of 1984. The benefits of these emulsions may be applied to pipeline transportation, to the combustion of heavy fuels, to increase the production rates of heavy-crude-oil wells, and to improve secondary recovery of heavy crude oil and bitumen. In this chapter, the emphasis is on discussion of the general characteristics of oil-in-water emulsions as related to their application for pipeline transportation. The incentive for developing this technology is to provide an alternative to the use of diluents or the application of heat for viscosity reduction in pipelines for heavy crude oil. The viscosity range for oil-in-water emulsions as compared to undiluted heavy crude oils and bitumens is illustrated in Figure 1. Also indicated in the figure is the viscosity specification for typical pipelines for heavy crude oil. As noted, the emulsion viscosity is well below the required level and provides operating benefits compared to normal operations in which viscosity reduction is achieved by use of diluents. 

Contamination in residual fuel oil may be indicated by the presence of excessive amounts of water, emulsions, and inorganic material such as sand and rust. Appreciable amounts of sediment in a residual fuel oil can foul the handling facilities and give problems in burner mechanisms. Blockage of fuel hlters (ASTM D-2068, ASTM D-6426) due to the presence of fuel degradation products may also result. This aspect of fuel quality control may be dealt with by placing restrictions on the water (ASTM D-95, IP 74), sediment by extraction (ASTM D-473, IP 53), or water and sediment (ASTM D-96, IP 75) values obtained for the fuel. 

As far as heavy crude oil-in-water emulsions are concerned, two cases are encountered. The first and most important one, which is commercially available, is the OAV emulsion to be handled and used as a fuel for thermoelectric plants and other energy generation purposes. The second one is the use of the 0/W conditioning as a low-viscosity vehicle for the pipeline transportation of viscous oil over long distances. In this case the oil has to be separated from the water at the end of the pipeline. Thus, the difference from the previous case is that the emulsion should be stable in the pipe, but easy to break up at the end station. 

If during the vaporization of water and burning of fuel, the emulsion droplet bulk temperature exceeds the superheat limit of water or fuel, bubble nucleation may take place within the droplet this may subsequently cause microexplosion. Based on the thermodynamic approach of finding the superheat limit, the non-dimensional superheat temperamre of a liquid at pressures smaller than the critical pressure is a linear function of pressure and is approximated as follows [17] ... 

With respect to commercial oxidation process development, Petro Star Inc. recently announced a desulfurization technology which removes sulfur from diesel fuels using chemical oxidation " " ". Desulfurization of diesel fuel is accomplished by first forming a water emulsion with the diesel fuel. In the emulsion, the sulfur atom is oxidized to a sulfone using peroxyacetic acid 138,145 -g 5y liquid/liquid extraction to remove the oxidized... 

Stanford, L., Rodgers, R., Marshall, A., Czarnecki, J. and Wu, X. (2007). Compositional Characterization of Bitumen/Water Emulsion Films by Negative-and positive-Ion Electrospray Ionization Ion Cyclotron Resonance Mass Spectrometry, Energy Fuels Vol. 21(No.2) 963-972. 

Platteau, O., Carrillo, M., (1995), Determination of metallic elements in crude oil-water emulsion by flame AAS, Fuel, 74, 74-76. 

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