Refined naphtha

Synonyms Naphtha solvent, high-flash naphtha, refined naphtha, and heavy naphtha describe various fractions and grades. 

Solvent naphtha a refined naphtha of restricted boiling range used as a solvent also called petroleum naphtha petroleum spirits. 

Asphalt can be generally classified as natural or artificial. Natural asphalts include bituminous materials laid down in natural deposits, such as those in Trinidad, and as gilsonites and grahamite bitumens, which are completely soluble in carbon disulfide. Artificial asphalt includes mainly petroleum-derived asphalts and, to a lesser extent, coal tar, water-gas tars, and their pitches. There are types of asphalt products obtained from straight-run asphalt (refined naphtha-based crude oils) hot, cutback, and emulsion asphalt. 

Properly speaking, steam cracking is not a refining process. A key petrochemical process, it has the purpose of producing ethylene, propylene, butadiene, butenes and aromatics (BTX) mainly from light fractions of crude oil (LPG, naphthas), but also from heavy fractions hydrotreated or not (paraffinic vacuum distillates, residue from hydrocracking HOC). 

Catalytic Processes. A second group of refining operations which contribute to gas production are the catalytic cracking processes, such as fluid-bed catalytic cracking, and other variants, in which heavy gas oils are converted into gas, naphthas, fuel oil, and coke (5). 

Gasoline. The naphtha fraction from cmde oil distillation is ultimately used to make gasoline. The two streams are isolated early in the refining scheme so that each can be refined separately for optimum blending in order to achieve the required specifications (see Gasoline and other motor fuels). 

Solvents. Petroleum naphtha is a generic term appHed to refined, pardy refined, or unrefined petroleum products. Naphthas are prepared by any of several methods, including fractionation of distillates or even cmde petroleum, solvent extraction, hydrocracking of distillates, polymerization of unsaturated (olefinic) compounds, and alkylation processes. Naphtha can also be a combination of product streams from more than one of these processes. 

Creosote. In coal-tar refining, the recovery of tar chemicals leaves residual oils, including heavy naphtha, dephenolated carboHc oil, naphthalene drained oil, wash oil, strained anthracene oil, and heavy oil. These are blended to give creosotes conforming to particular specifications. 

The principal sources of feedstocks in the United States are the decant oils from petroleum refining operations. These are clarified heavy distillates from the catalytic cracking of gas oils. About 95% of U.S. feedstock use is decant oil. Another source of feedstock is ethylene process tars obtained as the heavy byproducts from the production of ethylene by steam cracking of alkanes, naphthas, and gas oils. There is a wide use of these feedstocks in European production. European and Asian operations also use significant quantities of coal tars, creosote oils, and anthracene oils, the distillates from the high temperature coking of coal. European feedstock sources are 50% decant oils and 50% ethylene tars and creosote oils. 

A few industrial catalysts have simple compositions, but the typical catalyst is a complex composite made up of several components, illustrated schematically in Figure 9 by a catalyst for ethylene oxidation. Often it consists largely of a porous support or carrier, with the catalyticaHy active components dispersed on the support surface. For example, petroleum refining catalysts used for reforming of naphtha have about 1 wt% Pt and Re on the surface of a transition alumina such as y-Al203 that has a surface area of several hundred square meters per gram. The expensive metal is dispersed as minute particles or clusters so that a large fraction of the atoms are exposed at the surface and accessible to reactants (see Catalysts, supported). 

Natural gas and crude distillates such as naphtha from petroleum refining are used as feedstocks to manufacture a wide range of petrochemicals that are in turn used in the manufacture of consumer goods. Basic petrochemicals are... 

Naphtha is a generic term normally used in the petroleum refining industry for the overhead liquid fraction obtained from atmospheric distillation units. The approximate boiling range of light straight-run naphtha (LSR) is 35-90°C, while it is about 80-200°C for heavy straight-run naphtha (HSR). ... 

Naphthas obtained from cracking units generally contain variable amounts of olefins, higher ratios of aromatics, and branched paraffins. Due to presence of unsaturated compounds, they are less stable than straight-mn naphthas. On the other hand, the absence of olefins increases the stability of naphthas produced by hydrocracking units. In refining operations, however, it is customary to blend one type of naphtha with another to obtain a required product or feedstock. 

In the petroleum refining industry, hydrogen is essentially obtained from catalytic naphtha reforming, where it is a coproduct with reformed gasoline. 

When crude oil is refined, some of the processes yield additional gaseous products. The C3 and C4 constituents differ from those released from crude oil or from NGLs, which are saturated hydrocarbons. Refinery gases are high in unsaturates, e.g. propane (propylene) and butane (butylenes). These unsaturated hydrocarbons are a valuable source of chemical process intermediates and enjoy a large market alongside naphtha. 

The crude unit is the first unit in the refining process. Here, the raw crude is distilled into several intermediate products naphtha, kerosene, diesel, and gas oil. The heaviest portion of the crude oil,... 

Feedstock A higher fraction of 1,050°F+ (565°C+) in the feed. For many refiners, the regenerator temperature is the limit on addition of heavy ends to the feed. High-efficiency feed nozzles can be used. Naphtha quench can be added. 

Solvent Naphtha (160° benzol). A mixt of small percentages of benzene and toluene with xylene and higher homologs from coal tar. In crude form, a dark straw-colored liq, bp about 160° (80%), d 0.862—0.892g/cc, flash p about 78°F. When refined, a w-white liq, bp about 160° (90%), d 0.862-0.872g/cc, flash p about 78°F. May be obtained from coal tar by fractional distillation. When nitrated, used in Dynamites (Ref 5)... 

Nitrated Solvent Naphtha (N.S.N.). As nitration of crude solvent naphtha by the usual one-stage method results in yields that are too low, because of oxidation, E. Blecher et al (Ref 3) proposed nitrating only the refined material, and in two stages. The two-stage method is described in Colver, pp 255 686—87 (Ref 4). The product consists chiefly of 2,4,6-Trinitro-mesitylene (see under Mesitylene and Deriva- tives in this Vol), and 3,5,6-trinitropseudocumene, with small quantities of the nitrated products of xylene, ethylbenzene, etc... 

The plastic samples used in this study were palletized to a form of 2.8 3.2min in diameter. The molecular weights of LDPE and HDPE were 196,000 and 416,000, respectively. The waste catalysts used as a fine powder form. The ZSM-5 was used a petroleum refinement process and the RFCC was used in a naphtha cracking process. The BET surface area of ZSM-5 was 239.6 m /g, whose micropore and mesopore areas were 226.2 m /g and 13.4 m /g, respectively. For the RFCC, the BET surface area was 124.5 m /g, and micropore and mesopore areas were 85.6 m /g and 38.89 m /g, respectively. The experimental conditions applied are as follows the amount of reactant and catalyst are 125 g and 1.25-6.25 g, respectively. The flow rate of nitrogen stream is 40 cc/min, and the reaction temperature and heating rate are 300-500 C and 5 C/ min, respectively. Gas products were vented after cooling by condenser to -5 °C. Liquid products were collected in a reservoir over a period of... 

Oxygenate refining was limited to chemicals recovery from the Fischer-Tropsch aqueous product and acidic isomerization of the C5-C6 naphtha. The naphtha and distillate range oxygenates were removed by hydrodeoxygenation (HDO) in hydrotreaters, before further refining. 

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