Color diesel fuel

The tendency of the color to become darker with time is often indicative of chemical degradation. The test is conducted with the aid of a colorimeter (NF T 60-104 and ASTM D 1500) and by comparison with colored glass standards. The scale varies from 0.5 to 8. The French specifications stipulate that diesel fuel color should be less than 5, which corresponds to an orange-brown tint. Generally, commercial products are light yellow with indices from 1 to 2. 

Degradation of diesel fuel color and accumulation of insoluble deposits... 

Two criteria are used to characterize the behavior of diesel fuel in this area these are color and resistance to oxidation. 

Stability. Diesel fuel can undergo unwanted oxidation reactions leading to insoluble gums and also to highly colored by-products. Discoloration is beheved to be caused by oxidation of pyrroles, phenols, and thiophenols to form quiaoid stmctures (75). Eventually, these colored bodies may increase in molecular weight to form insoluble sludge. 

Detergent Additives. Diesel engine deposits ate most troublesome in the fuel dehvery system, ie, the fuel pump and both fuel side and combustion side of the injectors. Small clearances and high pressures mean that even small amounts of deposits have the potential to cause maldistribution and poor atomization in the combustion chamber. The same types of additives used in gasoline ate used in diesel fuel. Low molecular weight amines can also provide some corrosion inhibition as well as some color stabilization. Whereas detergents have been shown to be effective in certain tests, the benefit in widespread use is not fully agreed upon (77). 

VFO works well in gas turbines. In a nine-month test program, the combustion properties of VFO were studied in a combustion test module. A gas turbine was also operated on VFO. The tests were conducted to study the combustion characteristics of VFO, the erosive and corrosive effects of VFO, and the operation of a gas turbine on VFO. The combustion tests were conducted on a combustion test module built from a GE Frame 5 combustion can and liner. The gas turbine tests were conducted on a Ford model 707 industrial gas turbine. Both the combustion module and gas turbine were used in the erosion and corrosion evaluation. The combustion tests showed the VFO to match natural gas in flame patterns, temperature profile, and flame color. The operation of the gas turbine revealed that the gas turbine not only operated well on VFO, but its performance was improved. The turbine inlet temperature was lower at a given output with VFO than with either natural gas or diesel fuel. This phenomenon is due to the increase in exhaust mass flow provided by the addition of steam in the diesel for the vaporization process. Following the tests, a thorough inspection was made of materials in the combustion module and on the gas turbine, which came into contact with the vaporized fuel or with the combustion gas. The inspection revealed no harmful effects on any of the components due to the use of VFO. 

Trauzl Test. 21,.4% of TNT when pure (Ref 26) for mixts see below Uses. It does not gelatinize NC (Ref 15). It improves the octane rating of diesel fuels (Ref 26). It decreases the polymerization rate of methyl methacrylate (Ref 24), and styrene (Ref 23), but. does not inhibit the reaction. A review of its use as an oxidizer in rocket propints is given in Ref 33. TeNMe gives yellow to orange colors with olefins and aromatic compds. This is used as a diagnostic test for the presence of these groups in org analysis (Refs 6, 9, 16, 17 29)... 

Although hydroprocessing will remove most of the naturally occurring antioxidants contained in fuel, other less stable, more reactive components will also be reduced. As a whole, ultra-low sulfur diesel fuel will be much less prone to color degradation and deposit formation than earlier-era diesel fuels. 

A common method used to evaluate the stability of diesel fuel is to heat the fuel at a temperature of 300°F (148.9°C) for 90 minutes. After that time period, the fuel is analyzed for color change and deposit formation. 

PROBLEM DIESEL FUEL DARKENS IN COLOR AND SEDIMENT FORMS... 

Biodiesel methyl esters blend quite easily into petroleum based conventional diesel fuel. Biodiesel esters typically have better lubricity properties and higher cetane number ratings than conventional diesel fuel, but have poorer water demulsibility and color stability properties. At sub-zero temperatures, the handling characteristics of biodiesel becomes more difficult to control than conventional diesel fuel. 

Color Degradation of Diesel Fuel in Deep Desulfurization. The color of diesel fuel is degraded in the higher reactor temperature range of deep desulfurization.2) The color bodies (fluorescence compounds) are thought to be polyaromatics which are... 

Figure 8 Proposed Reaction Model Color Degradation of Diesel Fuel in Deep HDS...

Figure 9 Prediction of Color Degradation of Diesel Fuel by Proposed Model...

Figure 10 Catalyst Deactivation in Color Degradation Model for Deep HDS of Diesel Fuel...

The general appearance, or color, of diesel fuel is a useful indicator against contamination by residual (higher boiling) constituents, water, or fine solid particles. Therefore, it is necessary to make a visual inspection that clear fuel is being delivered (ASTM D-4176). 

Color, being part of the appearance of diesel fuel, should also be determined because the color of petroleum products is used for manufacturing control purposes. In some cases the color may serve as an indication of the degree of refinement of the material. Several color scales are used for determination (ASTM D-156, ASTM D-1209, ASTM D-1500, ASTM D-1544, IP 196). Typically the methods require a visual determination of color with colored glass disks or reference materials. 

The aromatic hydrocarbon content of diesel fuel affects the cetane number and exhaust emissions. One test method (ASTM D-5186) is applicable to diesel fuel and is unaffected by fuel coloration. Aromatics concentration in the range 1-75 mass% and polynuclear aromatic hydrocarbons in the range 0.5-50 mass% can be determined by this test method. In the method, a small aliquot of the fuel sample is injected onto a packed silica adsorption column and eluted with supercritical carbon dioxide mobile phase. Mono- and polynuclear aromatics in the sample are separated from nonaromatics and detected with a flame ionization detector. The detector response to hydrocarbons is recorded throughout the analysis time. The chromatographic areas corresponding to the mononuclear aromatic constituents, polynuclear aromatic constituents, and nonaromatic constituents are determined, and the mass-percent content of each of these groups is calculated by area normalization. 

Industrial Applications Plasma display panels liquid crystal display device color filters semiconductor devices photoresists recording materials inks toners " lenses pesticides laundry detergents textiles clay " gasoline " " diesel fuels " petroleum products" ... 

The chemical composition of a fuel is very complex and generally a lot of additives are added in order to improve some properties such as viscosity, oxidative stability, cold flow behavior, cetane number, color or smell etc. The impact on fuel properties of a complex mixture of miscellaneous additives is not always very well known. It has been already shown that it can bring a positive or negative synergy. Therefore, DSC and P-DSC can be very useful in evaluating with high accuracy and in a reasonable time the impact of a package of additives on the oxidative stability or the cold flow behavior of an alternative or conventional diesel fuel. 

Cetane quality of diesel fuels 0848, Acid wash color of aromatics X X ... 

The study on the spray combustion characteristics of 10% CPO blended with diesel fuel was conducted in a constant-volume combustion chamber. With the fixed experimental conditions such as spray ambient pressure and injection events, the effects of 10% CPO diesel at the injection line pressure of 100 MPa on spray combustion and flame stmcture were investigated using a photo diode and ICCD camera. Two-color method was also employed to predict combustion flame temperatures and KL factors. 

Methanol, which is also known as wood alcohol, is a colorless and odorless liquid alcohol fuel that can be made from biomass, natural gas, or coal. It is the simplest alcohol chemically and it may be used as an automobile fuel in its pure form (Ml 00), as a gasoline blend of typically 85% methane to 15% unleaded gasoline (M85). It is also used as a feedstock for reformulated gasoline. M100 or pure methanol may be used as a substitute for diesel. In M85, the gasoline is added to color the flame of burning fuel for safety reasons and to improve starting in cold weather. 

Black smoke is typically produced in diesel engines operating at or near full load. This occurs because the fuel volume injected exceeds the volume of air available in the combustion chamber needed for complete combustion of fuel carbon. Carbon particles and soot form to give the smoke a black or dark gray color. 

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