Gasoline distillation

Heavy residues are not always converted. The use of low sulfur light crude and crudes having a reduced ultimate residue (higher ratio of gasoline + distillates/vacuum residue) as well as natural gas utilization has been intensified. 

Cmde oil can be easily separated into its principal products, ie, gasoline, distillate fuels, and residual fuels, by simple distillation. However, neither the amounts nor quaUty of these natural products matches demand. The refining industry has devoted considerable research and engineering effort as well as financial resources to convert naturally occurring molecules into acceptable fuels. Industry s main challenge has been to devise new ways to meet the tremendous demand for gasoline without, at the same time, overproducing other petroleum products. 

Another important use of correlations is the optimization of existing unit operations. Cat cracking correlations can provide the refiner with valuable information for optimizing reactor temperature level, gasoline/distillate cut point, and feed and recycle rates. The practical application of this information can mean increased profitability for the cat cracking operation. 

It is likely that future commercialization of Methanol-to-Olefins (MTO) will take place in a fluid-bed reactor for many of the same reasons which encouraged fluid-bed MTG development, including better temperature control and constant product composition. The olefins produced by this process can be readily converted to gasoline, distillate and/or aviation fuels by commercially available technologies such as Mobil s MOGD process. 

Problems can occur if volatile gasoline components are lost due to evaporation or if gasoline is contaminated with any compound which effects a change in the volatility characteristics of the fuel. For example, engine warmup time will be extended if the relationship between the outside temperature and the percent gasoline distilled at 158°F (70°C) is exceeded. 

TABLE 4-6. Ambient Temperature and Gasoline Distillation Parameters Affecting Engine Warmup Time... 

Studies have been made thruout the refining industry in an effort to utilize selected stocks for the production of jet fuels. Basically, this would amount to determining the stability of many stocks, for example, straight run gasolines, distillates, kerosines, alkylate bottoms, and whatever else is available from refinery streams. Those with best heat stability, by laboratory test, could then be blended into jet fuels meeting required... 

Durene Formation - An aromatic compound, durene (1, 2, 4, 5-tetramethylbenzene) is produced in the MTG process. Durene has excellent research octane blending quality (110 RON clear) and boils within the gasoline distillation range (197°C) however, its freezing point is relatively high at 79°C. 

Catalytic cracking is the process of upgrading gas oil or even residual oil (heavy oil) to produce gasoline, distillates, light olefines, etc. Commercialized processes include fluid catalytic cracking (FCC), residual oil catalytic cracking (RFCC), and catalytic pyrolysis, etc. 

As with naphtha, the number of potential hydrocarbon isomers in the gasoline boiling range (Table 5.2) renders complete speciation of individual hydrocarbons impossible for the gasoline distillation range, and methods are used that identify the hydrocarbon types as chemical groups rather than as individual constituents. 

So what we have here is a chemical factory, to be brought on stream as the need arises. And we can go a step further and convert these olefins to an entire spectrum of products, through yet another ZSM-5 process Mobil olefins-to-gasoline + distillate, or MOGD (Refs. 20, 21). 

In the MOGD reaction, ZSM-5 oligomerizes light olefins, from either refinery streams or MTO, into higher molecular weight olefins that fall into the gasoline, distillate, and lubricant range. 

KMD-50,-80,-100. [Ferro/Keil] N,N -Disalicylidene-1,2-propanediamine sol ns. metal deactivators for gasoline, distillate fuels, and other petroleum prods. 

Experimental evidence showed that crystalline MCM-49 in propene oligomerization to components boiling in the gasoline, distillate and/or lube-range was more active than other zeolites such as ZSM-5, ZSM-23, ZSM-35 and MCM-22. ° The product contained much methyl branching (methyls/Ci2 >2.1) with more than 50% of the product in the gasoline-range. 

The MTG process can be combined with MTO technology as realized in the so-called MOGD process (Mobil Olefin to Gasoline/Distillate). Employing this process, olefins are synthesized in the first step followed by olefin oligomerization to gasoline or diesel using a ZSM-5 catalyst. Hence, this route also affords, unlike the MTG process, the production of synthetic diesel or jet fuel. ... 

---