Gas oil composition

Metal scavengers reported to date have few cracking properties. Thus, their addition to a commercial FCC initially cause a decrease in cracking activity. However, as metals are selectively deposited on the scavenger surface, deactivation rates are significantly reduced and a cross-over point is reached at which the FCC mixture is more active (in the presence of high metals) than the parent (undiluted) FCC (Figure 15). Cross-over points depend on gas oil composition, feed metal levels, and zeolite concentration (and type) in the host FCC and on the properties of the diluents this data must be obtained experimentally. Other important concepts for residuum catalyst development have recently been reviewed by O Connor and coworkers[59]. 

It is clearly evident that if VGO is not subtracted from the product, the results of conversion and product yields are wrongly determined. Conversions are different in 3.6%. Differences ranging from 0.5 to 2.8 vol% are observed for naphtha, kerosene, and gas oil composition and yields. VGO yield is obviously lower when subtracting the original VGO from the reactor product. 

An important application of this type of analysis is in the determination of the calculated cetane index. The procedure is as follows the cetane number is measured using the standard CFR engine method for a large number of gas oil samples covering a wide range of chemical compositions. It was shown that this measured number is a linear combination of chemical family concentrations as determined by the D 2425 method. An example of the correlation obtained is given in Figure 3.3. 

Gas oil fractions (204—565°C) from coal Hquefaction show even greater differences in composition compared to petroleum-derived counterparts than do the naphtha fractions (128). The coal-gas oils consist mostly of aromatics (60%), polar heteroaromatics (25%), asphaltenes (8—15%), and saturated... 

The main commercial source of methane, ethane, and propane is natural gas, which is found ia many areas of the world ia porous reservoirs they are associated either with cmde oil (associated gas) or ia gas reservoirs ia which no oil is present (nonassociated gas). These gases are basic raw materials for the organic chemical industry as well as sources of energy. The composition of natural gas varies widely but the principal hydrocarbon usually is methane (see Gas, natural). Compositions of typical natural gases are Hsted ia Table 2. 

Product composition from cracking atmospheric gas oil and vacuum gas oil °... 

Petroleum and chemical engineers perform oil reservoir simulation to optimize the production of oil and gas. Black-oil, compositional or thermal oil reservoir models are described by sets of differential equations. The measurements consist of the pressure at the wells, water-oil ratios, gas-oil ratios etc. The objective is to estimate through history matching of the reservoir unknown reservoir properties such as porosity and permeability. 

In an earlier study calorimetry achieved this objective for the compositional boundaries between two and three phases (2). Such boundaries are encountered both in "middle-phase microemulsion systems" of low tension flooding, and as the "gas, oil, and water" of multi-contact miscible EOR systems (LZ). The three-phase problem presents by far the most severe experimental and interpretational difficulties. Hence, the earlier results have encouraged us to continue the development of calorimetry for the measurement of phase compositions and excess enthalpies of conjugate phases in amphiphilic EOR systems. 

Another approach to produce chemicals via degraded molecules is the fast pyrolysis of biomass at high temperatures in the absence of oxygen. This gives gas, tar and up to 80 wt.% of a so-called bio-oil liquid phase, which is a mixture of hundreds molecules. Some of compounds produced by pyrolysis have been identified as fragments of the basic components of biomass, viz. lignin, cellulose and hemicellulose. The bio-oil composition depends upon the nature of starting... 

A typical C4 hydrocarbon stream coming from a gas oil or naphtha cracker, like that shown in the last chapter in Figure 5-4, might have the following composition ... 

Hydrocarbon distillates in the gas oil range ( diesel or derv ) are subject to duty when used as a road fuel. Gas oil, which is often identical to diesel oil in hydrocarbon composition, is exempt from duty when used for stationary machines. In order to prevent its misuse as a road fuel, gas oil is marked with a mixture of 1,4-dfhydroxyanthraquinone (quinizarin), 2-fiirfuraldehyde (furfural) and a red dye. An automatic method for the extraction, identification and determination of quinizarin in gas oil has been used hy the Laboratory of the Government Chemist (LGC) for some years. The presence of furfiiral provides evidence for legal prosecution and the numbers of analyses ordered in the UK merit automatic analysis. 

Feed composition effects on cross-over points were investigated by cracking a heavy gas oil (with API gravity of 23.7) containing 71% slurry oil. The high (34%) aromatics content of this feed is believed responsible for the greater coke make and increased deactivation rate of the host catalyst. As a result, a cross-over point below 0.25 wt% vanadium is obtained, see Figure 6. A loss of carbon selectivity is observed also in the DFCC mixture. In fact. 

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