Light distillate

During the production of mineral oils from vacuum distillates, one of the process steps, dewaxing , removes the high melting point materials in order to improve the oil s pour point. Dewaixing produces paraffins and waxes, the first coming from light distillates, and the second from medium or heavy distillates. 

A light distillate cut (light cycle oil - LCO) similar to gas oil but having high aromaticity and low cetane number. 

Property 0-GT" Naphtha 1-GT" Light distillate 2-GT" Medium distillate 3-GT Heavy distillate 4-GT Heavy residual... 

Bottoms and three side-cut strippers remove light ends from products and may utilize steam or reboilers. In Fig. 13-92 a reboiled stripper is utilized on the light distillate, which is the largest side cut withdrawn. Steam-stripping rates in side-cut strippers and at the bottom of the atmospheric column may vary from 0.45 to 4.5 kg (1 to 10 lb) of steam per barrel of stripped liquid, depending on the fraction of stripper feea hquid that is vaporizea. 

The carbon residue is a measure of the carbon compounds left in a fuel after the volatile components have vaporized. Two different carbon residue tests are used, one for light distillates, and one for heavier fuels. For the light fuels, 90% of the fuel is vaporized, and the carbon residue is found in the remaining 10%. For heavier fuels, since the carbon residue is large, 100% of the sample can be used. These tests give a rough approximation of the tendency to form carbon deposits in the combustion system. The metallic compounds present in the ash are related to the corrosion properties of the fuel. 

The residuum from vacuum distillation became, and still is, the basic component of residual fuel oil. It contains the heaviest fraction of the crude, including all the ash and asphaltenes. It is extremely high in viscosity and must be diluted with light distillate flux (a low viscosity distillate or residual fraction which is blended with a high viscosity residual fraction to yield a fuel in the desired viscosity range) to reach residual fuel viscosity. The lowest value distillates, usually cracked stocks, are used as flux. In some cases the vacuum residuum is visbroken to reduce its viscosity so that it requires less distillate flux. 

Originally cresylic acid was obtained from caustic waste streams that resulted from treating light distillates with caustic solutions to reduce H2S and mercaptans. Currently, most of these streams are hydrodesulfurized, and the product streams practically do not contain phenolic compounds. 

The liquid products were distilled to determine the yield and properties of the residual (343°C+) and light liquid (343°C ) products. Table VI shows that Runs 2 and 3 in Table IV resulted in 27 and 34 wt.% conversion of the 343°C+ fraction, while the sulfur in this fraction was reduced to 0.25 and 0.18 wt.%, respectively. The distillate and light liquid product (343°C ) are also upgraded in this process. The additional light distillates produced could presumably be recycled to the liquefaction reactor or utilized as low sulfur light distillate fuel. 

DF [light distillate fraction] A process for oxidizing light naphtha (a mixture of C4-C8 hydrocarbons) to acetic and other carboxylic acids. It operates in the liquid phase at 150 to 200°C. Developed by Distillers Company (now BP Chemicals) in England in the 1960s it was still operated there by that company in 1992. 

Fuel oil that is used for heating is graded from No. 1 fuel oil to No. 6 fuel oil, which covers light distillate oils, medium distillate, heavy distillate, a blend of distillate and residue, and residue oil. For example. No. 2 and No. 3 fuel oils medium to light distillate grades used in domestic central heating (Table 3.7). 

The term white distillate is applied to all the refinery streams with a distillation range between approximately 80 and 360°C (175 to 680°F) at atmospheric pressure and with properties similar to the corresponding straight-run distillate from atmospheric crude distillation. Light distillate products (i.e., naphtha, kerosene, jet fuel, diesel fuel, and heating oil) are all manufactured by appropriate blending of white distillate streams. 

Low-resolution nuclear magnetic resonance spectroscopy can also be used to determine percent by weight hydrogen in jet fuel (ASTM D3701) and in light distillate, middle distillate, and gas-oil (ASTM D4808). As noted above, chromatographic methods are not applicable to naphtha, where losses can occur by evaporation. 

The fuel choice for small stationary power plants is pipeline gas due to its availability for multiple commercial, light-industrial, and residential applications. Some users request that the fuel processor convert at least one additional fuel, i.e., a light distillate. 

There is the possibility of using other available fuels such as light distillates, ethanol, anaerobic digester gas, biomass, and refuse-derived fuel. However, these fuels apply to niche market applications. Fuel cell application here, if practical, will evolve from and after widespread uses. Users may require an alternate fuel, probably natural gas. 

Gasoline 333 gallons per tonne Light distillate 285 gallons per tonne Heavy distillate 256 gallons per tonne Crude oil 272 gallons per tonne... 

Prefractionation is an optional distillation process to separate economic quantities of very light distillates from the crude oil. Lower temperatures and higher pressures are used than in atmospheric distillation. Some process water can be carried over to the prefractionation tower from the desalting process. 

Selective tertiary-huimoX (tBA) dehydration to isobutylene has been demonstrated using a pressurized reactive distillation unit under mild conditions, wherein the reactive distillation section includes a bed of formed solid acid catalyst. Quantitative tBA conversion levels (>99%) have been achieved at significantly lower temperatures (50-120°C) than are normally necessary using vapor-phase, fixed-bed, reactors (ca. 300°C) or CSTR configurations. Substantially anhydrous isobutylene is thereby separated from the aqueous co-product, as a light distillation fraction. Even when employing crude tBA feedstocks, the isobutylene product is recovered in ca. 94% purity and 95 mole% selectivity. 

This process is used frequently to sweeten gasoline and light distillate streams. In the first phase of Merox processing, mercaptans are extracted from the fuel with caustic. A sweetening process follows and involves sparging a caustic/fuel mixture with air in the presence of a catalyst. Remaining mercaptans then react to form... 

In naphtha and light distillate components, oxygen-containing compounds appear as carboxylic acids and phenols. Most of these compounds concentrate in the kerosene, fuel oil, and lighter lubricant fractions. Straight-run gasoline, heavy distillates, and residual fuels usually contain few acids. 

Clay Treating A process used to improve the color of cracked naphthas and light distillates. It is also used to remove surface active agents which can negatively impact the WSIM rating of jet fuel. 

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