Sediment Formation

However, simplification of the refining procedure is not always the end result. IncompatibiUty of different cmde oils, which can occur if, for example, a paraffinic cmde oil is blended with a heavy asphaltic oil, can cause sediment formation ia the unrefined feedstock or ia the products, thereby complicating the refinery process (5). 

Several techniques can be used to separate phenol. Solvent extraction using gas oil or lube oil (process MSAs Sj and S2, respectively) is a potential option. Besides the purification of wastewater, the transfer of phenol to gas oil and lube oil is a useful process for the oils. Phenol tends to act as an oxidation inhibitor and serves to improve color stability and reduce sediment formation. The data for the waste streams and the process MSAs are given in Tables 3.4 and 3.5, respectively. 

Saski EK, A Vahatalo, K Salonen, MS Salkinoja-Salonen (1996b) Mesocosm simulation on sediment formation indnced by biologically treated bleached kraft pulp mill wastewater in freshwater recipients. In Environmental Fate and Effects of Pulp and Paper Mill Effluents (Eds MR Servos, KR Munlittrick, JH Carey, and GJ van der Kraak), pp. 261-270. St Lucie Press, Delray Beach, FL. 

Age correction is also generally required in order to correct for the decay of excess °Th (or Pa) since the formation of the sediment. Only by such a correction can the conditions at the time of sediment formation be determined. For °Thxs, this correction is given by ... 

Pore size optimization is one area where developmental efforts have been focused. Unimodal pore (NiMo) catalysts were found highly active for asphaltene conversion from resids but a large formation of coke-like sediments. Meanwhile, a macroporous catalyst showed lower activity but almost no sediments. The decrease of pore size increases the molecular weight of the asphaltenes in the hydrocracked product. An effective catalyst for VR is that for which average pores size and pore size distribution, and active phase distribution have been optimized. Therefore, the pore size distribution must be wide and contain predominantly meso-pores, but along with some micro- and macro-pores. However, the asphaltene conversion phase has to be localized in the larger pores to avoid sediment formation [134],... 

Stanislaus, A., Absi-Halabi, M., Khan, Z., Influence of Catalyst Pore Size on Asphaltenes Conversion and Coke-Like Sediments Formation During Catalytic Hydrocracking of Kuwait Vacuum Residues, In Catalysts in Petroleum Refining and Petrochemical Industries. Studies in Surface Science and Catalysis. 1996, Elsevier New York, USA. pp. 189-197. 

Tests should also be carried out for sediment if the naphtha has been subjected to events (such as oxidation) that could lead to sediment formation and instability of the naphtha and resulting products. Test methods are available for the determination of sediment by extraction (ASTM D473, IP 285) or by membrane filtration (ASTM D4807 IP 286) and the determination of simultaneously sediment with water by centrifugation (ASTM D96, D1796, D2709, D4007 IP 373, 374). 

Nitrogen occurs in residua, and therefore in residual fuel oil, and causes serious environmental problems as a result, especially when the levels exceed 0.5% by weight, as happens often in residua. In addition to the chemical character of the nitrogen, the amount of nitrogen in a feedstock determines the severity of the process, the hydrogen requirements, and to some extent, the sediment formation and deposition. 

Gamma-ray log This is a log of the natural formation radioactivity level. Gamma radiation is measured along the borehole to determine the rock and sediment formations... 

The sedimentary and metamorphic rocks uplifted onto land have become part of continents or oceanic islands. These rocks are now subject to chemical weathering. The dissolved and particulate weathering products are transported back to the ocean by river runoff. Once in the ocean, the weathering products are available for removal back into a marine sedimentary reservoir. At present, most mass flows on this planet involve transport of the secondary (recycled) materials rather than the chemical reworking of the primary (juvenile) minerals and gases. The natirre of these transport and sediment formation processes has been covered in Chapters 14 through 19 from the perspective of the secondary minerals formed. We now reconsider these processes from the perspective of impacts on elemental segregation between the reservoirs of the crustal-ocean-atmosphere factory and the mantle. 

Pryor, M.J. Evans, U.R. (1950) The reductive dissolution of ferric oxide in acid. I. The reductive dissolution of oxide films present on iron. J. Chem. Soc., 1259-1266 Puchelt, H. (1973) Recent iron sediment formation at the Kameni Islands, Santorini (Greece). In Amstutz, G.C. Bernard, A.J. (eds.) Ores in sediments. Springer Berlin, 227-245... 

Theoretically, use of fuel as a coolant is convenient. But, it is well known that heating oils for even short periods of time accelerates gum and sediment formation. (In fact, this is the basis for many stability prediction tests in the petroleum industry.) It was not unexpected then, that when fuels are heated in aircraft fuel systems, temperatures would be high enough to cause some fuel degradation... 

Microorganisms can cause various degrees of haze, cloudiness, or sediment formation as well as changes in the composition of wine constituents by metabolizing components of the wine. 

The solubility of neodymium carboxylates in organic solvents is also improved by the addition of electron donors such as acetylacetone, tetrahy-drofuran, N,N -dimethylformamide, thiophene, diphenylether, triethylamine, pyridine, organic phosphorus compounds etc. Also the storage stability of neodymium carboxylates in organic solutions (reduction of sediment formation) is increased by these additives. Mixtures of the Nd-precursor and the respective additives are reacted in the temperature range 0-80 °C. The sequential addition of Al-compound and halide donor yield the active polymerization catalysts [409,410]. 

Chen, N., Bianchi, T.S., and Bland, J.M. (2003a) Novel decomposition products of chlorophyll-a in continental shelf (Louisiana shelf) sediments Formation and... 

The sedimentation is strongly controlled by the inherited character of the relief-forming processes that proceeded against the background of the Holocene history of the Black Sea. Sediment formation is also influenced by the solid riverine runoff and coastal abrasion, slope-derived supply, and biogenic and chemogenic matter. 

In the West and East Pontian regions, the sediment formation is strongly influenced by mountain rivers and numerous water channels that supply terrigenous matter as well as by coastal abrasion. 

During the first phases of the delta development, the main river flow ran to the sea along the southern boundary of the delta (the Gheorghe branch at present). Then the ancient Sulina branch was formed. Only by the 18th century, after filling up the shallow inland parts of the former bay by river sediments, formation of the marine protruding Chilia delta in the open nearshore zone started. This event took place around 1740s. The most active... 

The testing used similar procedures to those described for the laboratory test program. The fuels were blended in tank trucks at the ECLP pilot plant at Baytown, Texas and driven to Charleston, South Carolina. The fuels were loaded hot and remained at an elevated temperature in insulated tank trucks. Fuel temperature for the combustion of the EDS fuels was approximately 43°C. The preheating system was bypassed with the EDS fuels to prevent sediment formation due to incompatibility in the fuel... 

Conditions of rock weathering, sediment formation and therefore geochemical processes as a whole were different in the geological past (Veizer, 1973) oxygen and carbon dioxide partial pressures were different and there were more basic rocks available for weathering. The Precambrian sediments of the Canadian and Scottish shields are discussed by J. G. Holland and Lambert (1973) in relation to the composition of the continental crust. 

Kastner M. (1981) Authigenic silicates in deep sea sediments formation and diagenesis. In The sea (ed. C. EmiUani). Wiley, New York, pp. 915-980. 

In the sediment from industrial winterization, additional minor fatty acids and alcohols with 26 to 32 carbon atoms in the chain have been found in waxes and triacylglycerols (15). Most of these compounds are extracted from the seed coat and can initiate sediment formation in canola oil (16). 

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