 Fluid catalytic cracking or FCC is the last step in the evolution of cat cracking processes Also introduced in 1942 just like TCC or Thermo4 cat cracking during the Second World War in an effort to make high octane number gasoline remember that high octane number relates to high power as you can have higher compression ratios in the combustion engines. FCC really shows an excellent integration of the cracking reactor an endothermic reactor with the catalyst regenerator and exothermic reactor for very high thermal efficiency. FCC is now used universally in all refineries throughout the world has replaced all the previous cat cracking processes. Now in FCC in the feed that is gas oil preheated to about 300 degrees Fahrenheit is introduced into the reactor with steam the riser part of the reactor where the hot catalyst particles as you see the green line coming from the catalyst regenerator are philodized the particles are philodized because they're smaller particles they are philodized in flowing gases and vapors so they have a huge surface area to meet the incoming feed at temperatures that are close to 1000 degrees Fahrenheit so cracking reactions on these very fine particles that are philodized and flowing with the reactants takes place in a very short space of time something that could be measured with seconds and the products are sent to a fractionator after going through a series of cyclones obviously to separate the small philodized particles of the catalyst in the fractionators the products as usual are separated into gas gasoline light cycle oil heavy cycle oil and finally the heaviest fractions decant oil remember that LCO is used in the US for making diesel fuel through hydro cracking and hydrogenation and decant oil could be used as fuel oil or as feed stock for making carbon black or by coking to make needle coke for graphite electrodes coming back to the reactor the cat cracking reactor the coked catalyst now the end of the riser where this cracking reaction takes place are sent to the regenerator it's now fully coked on the surface lost its activity through the red line is sent to the regenerator where air is introduced to burn off the coke the temperatures in the regenerator could reach to 1300 to 1400 degrees Fahrenheit should remember that the catalyst now are much improved as well it may include zeolites that would take high temperatures and and very controlled reactivities through pore size distribution and so forth so the products combustion products or flu gases from this catalyst regenerator could be sent to a co boiler because the gas may contain significant amount of carbon monoxide which could be burned to a co2 to provide additional heat or to generate additional heat so the catalysts that are now regenerated are sent to the reactor to close the catalyst cycle through that green line as you see to meet the incoming feed so our catalyst cycle is pretty much complete at this point but note this excellent integration thermal integration of the catalyst regeneration the exothermic process with the cracking reactions where the catalysts that are heated in the regenerator are sent in a very effective manner to the reactor without much heat loss so that is the ultimate if you will thermal efficiency of a process and that's why FCC is now the universally accepted catalyst cracking process