Refining cracking process

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). 

Since 1945, the fluid catalytic cracking process has rapidly overtaken fuel production and has become the central technology in the U.S. petrochemicals industi y. With fluid cracking, the scale of petrochemical operations grew eiinriiiotisly. For the first time, refiners could process virtually any volume of oil rapidly and efficiently. 

Before the advent of the catalytic cracking process, thermal cracking was the primary process available to convert low-value feedstocks into lighter products. Refiners still use thermal processes, such as delayed coking and visibreaking, for cracking of residual hydrocarbons. 

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... 

Gyro Also called Gyro-cracking. An early vapor-phase thermal cracking process for refining petroleum. 

They are not found to any extent in natural products, but are produced in the destructive distillation of complex natural substances, such as coal, and are formed in large amounts in petroleum refining, particularly in the cracking process. The first member of the series is ethylene, C2H4. The dienes contain two double bonds between pairs of carbon atoms in the molecule. They are related to the complex hydrocarbons in natural rubber and are important in the manufacture of synthetic rubber and plastics. The most important members of this series are butadiene, C4H5 and isoprene, CsHg. 

The first serious notice of C4 hydrocarbons came with the development of refinery cracking processes. When catalytic cracking became popular, refiners were faced with disposing of a couple of thousand barrels per day of a stream containing butane, butylenes, and small amounts of butadiene. Their first thought was to burn it all as refinery fuel, but then they developed the alkylation process. With that, they could undo some of the molecule shatter that took place in the crackers and reassemble some of the smaller pieces as alkylate, a high-octane gasolinerblending component. 

Because of the tendency of thermal cracking to produce coke as a by-product of the process, most refiners have replaced thermal cracking units with catalytic cracking processes. However, in certain parts of the world, thermal cracking units still exist. 

Crude oil typically contains little to no olefinic compounds. Through refining and processing, however, olefins are produced and become a part of various crude oil fractions. Olefins can be found in thermally cracked and catalytically cracked gasoline fractions as well as in FCC cycle oils and coker gas oils. For this reason, it is not unusual for finished gasoline and distillate blends to contain a high-olefin-content stream. 

Cracking process—Congresses. 2. Petroleum—Refining—Congresses. 3. Hydrogenation—Congresses. 

Fig. 18.19. Fluid catalytic cracking—UOP LLC. Combustor style is used to crack process gas oils and moderately contaminated resids, while the two-stage unit is used for more contaminated oils. (Source Hydrocarbon Processing, 2004 Refining Process Handbook. CD-ROM. September 2004 copyright 2004 by Gulf Publishing Co., all rights reserved.)...

In petrochemical and oil refining operations, the zeolite is primarily responsible for the catalyst s activity, selectivity and stability (catalytic, thermal and hydrothermal). The fluid catalytic cracking process (FCC) is the most widely used of the oil refining process and is characterized by the use of a finely divided catalyst, which is moved through the processing unit. The catalyst particles are of such a size (about 70 pm) that when aerated with air or hydrocarbon vapor, the catalyst behaves like a liquid and can be moved easily through pipes. 

---