Sediment diesel fuel

The procedure most commonly employed (NF M 07-047 or ASTM D 2274) Is to age the diesel fuel for 16 hours while bubbling oxygen into it at 95°C. The gums and sediment obtained are recovered by filtration and weighed. There is no official French specification regarding oxidation stability however, in their own specifications, manufacturers have set a maximum value of 1.5 mg/100 ml. 

Hematological Effects. One case study reported that decreased hemoglobin concenu-ation and an increase in erythrocyte sedimentation rate were noted in one man after washing his hands with diesel fuel over several weeks (Crisp et al. 1979). Effects resulting from inhalation versus dermal exposure could not be distinguished in this case. 

A pilot-scale demonstration remediating harbor sediment was conducted 1 year before the SITE demonstration. Based on the pilot-scale demonstration, the processing costs for a fuU-scale, 110-ton/day unit were projected to be 230/ton (September 1992 U.S. dollars). It is assumed that the unit will be down approximately 30% of the time for maintenance and design improvements in the first year of operation. Based on this system availability, 28,105 tons can be processed in one year. This cost included estimates for variable costs, fixed costs, and deprecia-tion/insurance. Variable costs include diesel fuel for a mobile generator, hydrogen, and caustic. Fixed costs include labor diesel fuel for pumps, heaters, process equipment, and instrumentation propane, water and sewer and parts and supplies. Depreciation/insurance costs include capital cost depreciated over a 3-year period, general insurance costs, and pollution liabihty insurance. This analysis does not include costs for setup and demobilization (D128007, pp. 5.12-5.14). 

According to the technology developer, the technology can treat soils, sludges, and dredged sediments contaminated with organic contaminants ranging from diesel fuel to polychlorinated biphenyls (PCBs). 

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

High gum level/ sediment in gasoline or diesel fuel... 

Diesel fuel spill TT whole sediment I,I (Keller et ah, 1998)... 

Keller, A.E., Ruessler, D.S. and Chaffee, C.M. (1998) Testing the toxicity of sediments contaminated with diesel fuel using glochidia and juvenile mussels (Bivalvia, Unionidae), Aquatic Ecosystem Health and... 

CDDs have been measured in all environmental media including ambient air, surface water, groundwater, soil, and sediment. While the manufacture and use of chlorinated compounds, such as chlorophenols and chlorinated phenoxy herbicides, were important sources of CDDs to the environment in the past, the restricted manufacture of many of these compounds has substantially reduced their current contribution to environmental releases. It is now believed that incineration/combustion processes are the most important sources of CDDs to the environment (Zook and Rappe 1994). Important incineration/combustion sources include medical waste, municipal solid waste, hazardous waste, and sewage sludge incineration industrial coal, oil, and wood burning secondary metal smelting, cement kilns, diesel fuel combustion, and residential oil and wood burning (Clement et al. 1985 Thoma 1988 Zook and Rappe 1994). 

A research vessel on Lake Ontario had a slow leak of diesel fuel as it cruised around the lake sampling sediment. Over a few days, this vessel lost 50 gal of diesel fuel. The research scientists on this vessel patched the leak, and then, being a conscientious group, they began to wonder about the environmental ramifications of this spill. They assumed that diesel fuel was composed entirely of n-hexadecane (C16H34), and looking... 

Diesel fuel made from the thermal cracking of plastics is more susceptible to oxidation and polymerization than refinery-made diesel fuels. This is because plastic-derived diesel fuels generally have terminal unsaturation (i.e. double bonds) at the ends of the diesel chains as a result of the P-scission chain cleavage. Over time free radicals that form in the plastic-derived diesel fuels during storage cause the diesel chains with double bonds (a-olefins) to polymerize resulting in a sludgy sediment also known as gum . 

The expected life of a diesel fuel is indicated by the oxidation stability test (ASTM D-2276). The test measures how much gum and sediment will be deposited after conditioning the fuel at 120°C in the presence of oxygen for 16 h. It roughly corresponds to a years storage at 25°C. A result of less than 20 mg/L of sediment and gum after the test is considered acceptable for normal diesel. 

HSD Stabilizer (Diesel Stabilizer) additive is a multicomponent, oil soluble formulation, specially designed to maintain the total sediments level in diesel fuel within the specified limits, as per ISO 1460 1995. The additive will ensure that the diesel does not deteriorate on storage and the fuel system is protected from deposit formation and corrosion. The additive consists of three major components, namely ... 

Water can contribute to filter blocking and cause corrosion of the injection system components. In addition to clogging of the filters, sediment can cause wear and create deposits both in the injection system and in the engine itself. Thus one of the most important characteristics of a diesel fuel, the water and sediment content (ASTM D-1796, IP 75), is the result of handling and storage practices from the time the fuel leaves the refinery until the time it is delivered to the engine injection system. 

Table 6.2. Effect of antiflocculation additive (CrStj) on sedimentation stability of water-Diesel fuel emulsions stabilised by nonionics...

Reddy, S. R., 1988. Filter plugging by insoluble sediment in diesel fuels. In H. L. Chesneau and M. M. Dorris, (eds.). Distillate Fuel Contamination, Storage and Handling, Philadelphia, American Society for Testing and Materials, pp. 82-94. 

In order to circumvent these technical problems "pour-point depressants" are added (Giorgio Kern, 1983 Beiny et al., 1990). Generally, depressants are copolymers consisting of crystalline and amorphous segments that have the capacity to self-assemble in solution without sedimentation even at temperature well below 0°C. They interact favourably with paraffins and moderate the wax crystals morphology so that crude oils and middle distillates remain fluid as their temperature passes through that of PP. The mechanisms by which these polymeric systems modify the wax crystal size and shape are however incompletely understood. As such, the synthesis and choice of additives for crude oils and diesel fuels are largely trial and error rather than based on scientific principles. Moreover,... 

Typical viscosities for light (benzene) and dense (diesel fuel) NAPLs are 0.65 and 3.60 cP, respectively at 25°C. Materials like creosote and coal tar can have viscosities as high as 20 cP at ambient conditions and may not be well represented by this method. Equation 5.42 can be used along with the porous media formulae outlined above (Equations 5.33 and 5.39) to estimate effective diffusivities of soil or sediment when NAPLs are present. 

Other properties of interest are carbon residue, sediment, and acidity or neutralization number. These measure respectively the tendency of a fuel to foul combustors with soot deposits, to foul filters with dirt and rust, and to corrode metal equipment. Cetane number measures the ability of a fuel to ignite spontaneously under high temperature and pressure, and it only applies to fuel used in Diesel engines. Typical properties ol fuels in the kerosene boiling range are given in Table 1. 

CRMs for Contaminants in Environmental Matrices For nearly two decades NIST has been involved in the development of SRMs for the determination of organic contaminants such as polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and chlorinated pesticides in natural environmental matrices such as fossil fuels (Hertz et al.1980 Kline et al. 1985), air and diesel particulate material (May and Wise 1984 Wise et al. 2000), coal tar (Wise et al. 1988a), sediment (Schantz et al. 1990, 1995a Wise et al. 1995), mussel tissue (Wise et al. 1991 Schantz et al. 1997a), fish oil, and whale blubber (Schantz et al. 1995b). Several papers have reviewed and summarized the development of these environmental matrix SRMs (Wise et al. 1988b Wise 1993 Wise and Schantz 1997 Wise et al. 2000). Seventeen natural matrix SRMs for the determination of organic contaminants are currently available from NIST with certified and reference concentrations primarily for PAHs, PCBs, chlorinated pesticides, polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofiirans (PCDFs) see Table 3.11. 

Marine residual fuels bunker fuel oil Grades ISO RMA through RML marine residual fuel and bunker fuel are blended from components such as atmospheric resid, vacuum resid, visbreaker resid, FCC bottoms, low-grade distillate, and cracked components. Bunker fuel has a maximum viscosity of 550 cSt 122°F (50°C), density of 0.990 g/cc, and sediment of 0.1 wt%. ISO marine fuel oil viscosities range from 10 to 55 cSt 212°F (100°C). These fuels are used in slow-speed diesel engines and boilers. 

As diesel ages a fine sediment and gum forms in the fuel brought about by the reaction of diesel components with oxygen from the air. The fine sediment and gum will block fuel filters, leading to fuel starvation and engine failure. Frequent filter changes are then... 

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