Middle distillate fuel improvers

The information presented in this paper shows that shale oil has an excellent potential as a source for high quality middle distillate fuels. The Shale-II pregram produced fuels with properties significantly improved compared to the properties of the fuels produced in Shale-I. In particular, Shale-II fuels exhibit vastly better stability, lower freezing points, and lower oxides of nitrogen during combustion. 

Simple conventional refining is based essentially on atmospheric distillation. The residue from the distillation constitutes heavy fuel, the quantity and qualities of which are mainly determined by the crude feedstock available without many ways to improve it. Manufacture of products like asphalt and lubricant bases requires supplementary operations, in particular separation operations and is possible only with a relatively narrow selection of crudes (crudes for lube oils, crudes for asphalts). The distillates are not normally directly usable processing must be done to improve them, either mild treatment such as hydrodesulfurization of middle distillates at low pressure, or deep treatment usually with partial conversion such as catalytic reforming. The conventional refinery thereby has rather limited flexibility and makes products the quality of which is closely linked to the nature of the crude oil used. 

Although desulfurization is a process, which has been in use in the oil industry for many years, renewed research has recently been started, aimed at improving the efficiency of the process. Envii onmental pressure and legislation to further reduce Sulfur levels in the various fuels has forced process development to place an increased emphasis on hydrodesulfurization (HDS). For a clear comprehension of the process kinetics involved in HDS, a detailed analyses of all the organosulfur compounds clarifying the desulfurization chemistry is a prerequisite. The reactivities of the Sulfur-containing structures present in middle distillates decrease sharply in the sequence thiols sulfides thiophenes benzothiophenes dibenzothio-phenes (32). However, in addition, within the various families the reactivities of the Substituted species are different. 

The pour point of a crude oil or product is the lowest temperature at which an oil is observed to flow under the conditions of the test. Pour point data indicates the amount of long-chain paraffins (petroleum wax) found in a crude oil. Paraffinic crudes usually have higher wax content than other crude types. Handling and transporting crude oils and heavy fuels is difficult at temperatures helow their pour points Often, chemical additives known as pour point depressants are used to improve the flow properties of the fuel. Long-chain n-paraffins ranging from 16-60 carhon atoms in particular, are responsible for near-ambient temperature precipitation. In middle distillates, less than 1% wax can be sufficient to cause solidification of the fuel. ... 

Deen, H. E., A. M. Kaestner, and C. M. Stendahl. 1968. Additives to improve quality and low temperature handling of middle distillate and residual fuels. Published paper presented at World Petroleum Congress, Paris, France. 

Research is likely to continue with a view to improving methods of sweetening and removing mercaptans from all middle distillates including heater oil. It is doubtful, however, that much effort will be applied specifically toward desulfurization of heater oils except in cases where fuel instability and poor performance of equipment are due to sulfur compounds or where the treatment for stability improvement simultaneously lowers sulfur content. 

So how much investment will be made to process low-sulfur fuels A recent Energy Information Administration (EIA) report estimates that U.S. refiners will invest 6.3-9.3 billion to reach full compliance with the ultra-low sulfur diesel (ULSD) rule through 201 1.33 For Europe, refiners made investments of nearly 22.9 billion from 1997 to 2005 to meet gasoline and diesel specifications. From 2005 to 2015, an additional 9.7-14 billion may be spent on improving the quantity and quality of middle distillates in Europe.15 Thus, considerable investment will be necessary to bring cleaner fuels to market. 

Comprehensive two-dimensional gas chromatography (GC X GC) is another hyphenated technique where two different chromatographic separation mechanisms act in concert to greatly improve component separation and identification. To date, GC X GC has been used to analyze light and middle distillate petroleum products. GC X GC has successfully separated and quantitated oxygenates, BTEX, and heavier aromatics in gasoline. GC X GC has been used to smdy the composition of kerosene, gas oil, cycle oil, and for forensic fingerprinting of marine diesel fuel spills. 

Uses. A marked improvement in the low temperature flow property of a fuel oil having a bp 120-150°C by adding a novel compound prepared by reacting pri-, sec- or tert-aliphatic amine containing alkyl group of 1-30 C-atoms with 9,10-dihydroanthracene-9,10-endo-aP-succinic anhydride (or acid) there of together with a polymer having ethylene structure present relates compound temperature fluidity middle distillate composition petroleum fuel. 

Wache, W., Datsevich, L., Jess, A., and Neumann, G. (2006) Improved deep desulfurisa-tion of middle distillates by a two-phase reactor with pre-saturator. Fuel, 85, 1483-1493. 

A recent report by Shell Research and Technology Center showed that commercial noble metal-based catalysts for deep hydrogenation of fuels operate in a regime where the large majority of the metal sites are poisoned by sulfur, even when sulfur tolerance has been improved by choosing modem support functions and metals. Thus, these catalysts are currently used only after a deep desulfurization over Ni-Mo catalysts and subsequent removal of H2S, as is also the case in the Shell Middle Distillate Hydrogenation process and the Lummus/Criterion SynSat process . Noble metal catalysts that can operate in a stacked-bed reactor with a Ni-Mo catalyst without intermediate H2S removal have not been reported . 

Sharing of past major incidents with other oil and gas industries provides useful input data for similar process industries in order to identify the most critical barriers and improve their safety processes. One poignant example highlights this matter. In 1998 there was an accident in the gas compression stage of a Middle East oil and gas plant which caused 7 dead as a result of fuel accumulation and vapor cloud explosion which was very similar to the Texas City Refinery disaster on March 23, 2005 in which a distillation tower was overfilled and an uncontrolled release of hydrocarbons led to a major explosion and fires. Fifteen people were killed and 180 were injured in the worst disaster in the United States in a decade. In both incidents, excess hydrocarbons were diverted into a pressure relief system that included a blowdown stack. In the Iranian case, it was equipped with a flare, but one which the operator didn t ignite in Texas City the blowdown stack was not equipped with a flare to burn off hydrocarbons as they were released. As a result, the flammable overflow from the tower entered the atmosphere. Ignition of the escaped hydrocarbons was enabled by startup of a nearby vehicle resulted in the explosion and subsequent fires (Hopkins, 2008). This example shows the repetitive patterns of accidents, and root causes of events all over the world in this sector. The lesson of this paper is that accidents in one country, where the scenarios are very similar, can and should serve as lessons to prevent the same scenario being actualized in other countries. 

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