Contacting process with oils

Catalytic cracking is a process for the conversion of heavy petroleum cuts into gasoline. The catalyst is constituted of microspheres of about 60 /zm diameter contains 10 to 40 % of an acid Y zeolite (REY, USHY...) dispersed in a matrix (clay + binder). This catalyst circulates rapidly in the unit, its contact time with oil in the riser reactor (T 530 0) being of several seconds. The coked catalyst (about 1 wt % coke) is transported to the regenerator where the introduction of air makes possible, in a few minutes the combustion of coke at high temperature (about 700 C). The use of heavier and heavier feeds creates several problems during the regeneration steps ... 

Petroleum distillation units generate considerable wastewater. The process water used in distillation often comes in direct contact with oil and can be highly contaminated. Both atmospheric distillation and vacuum distillation produce an oily, sour wastewater (condensed steam containing hydrogen sulfide and ammonia) from side-stripping fractionators and reflux drums. 

Like most separation processes in the refinery, the process water used in coker fractionators (as is also the case in other product fractionators) often comes in direct contact with oil and can have a high oil content (much of that oil can be recovered through wastewater oil recovery processes). Thus, the main constituents... 

Hydrotreating generates sour wastewater from fractionators used for product separation. Like most separation processes in a refinery, the process water used in fractionators often comes in direct contact with oil and thus can be highly contaminated. It also contains hydrogen sulfide and ammonia and must be treated along with other refinery sour waters. In hydrotreating, sour wastewater from fractionators is produced at the rate of about I.O gallon per barrel of feed. 

The modern industrialized world would be inconceivable without catalysts. Catalysis is a multidisciplinary area of chemistry, particularly industrial chemistry where around 85% of all products pass through at least one catalytic stage. Anyone who is involved with chemical reactions will eventually have something to do with catalysts. For example, the contact process for the production of sulfuric acid was introduced as early as 1880. After World War II, some catalysts for crude oil processing appeared on the US and European markets and, from an environmental standpoint, they became crucial from 1970 onwards because of their contribution to the protection of the environment and thus to a generally higher standard of living. 

Fluid catalytic cracking (FCC) of heavy oil fractions is a well-known process in oil refineries. Numerous books (e.g., 1—3) and publications about the different aspects of this subject are available. This chapter is concerned with the modeling of the transfer line or riser reactor of an FCC unit (FCCU) or of a pilot plant. The riser reactor in FCCUs is a vertical pipe about 1 m in diameter and 10-30 m in height. The hot catalyst coming from the regenerator at about 710 ° C first comes in contact with steam and is fluidized. Then, at a height of some meters above, the catalyst is mixed with the preheated feedstock at about 300 ° C. 

Foams, in the form of froths, are intimately involved and critical to the success of many mineral-separation processes (Chapter 10). Foams may also be applied or encountered at all stages in the petroleum recovery and processing industry (oil-well drilling, reservoir injection, oil-well production and process-plant foams). A class of enhanced oil recovery process involves injecting a gas in the form of a foam. Suitable foams can be formulated for injection with air/nitrogen, natural gas, carbon dioxide, or steam [3,5]. In a thermal process, when a steam foam contacts residual crude oil, there is a tendency to condense and create W/O emulsions. Or, in a non-thermal process, the foam may emulsify the oil itself (now as an O/W emulsion) which is then drawn up into the foam structure the oil droplets eventually penetrate the lamella surfaces, destroying the foam [3], See Chapter 11. 

Foamed emulsions are disperse systems with two disperse phases (gas and liquid) in the disperse medium (surfactant solution). Water foamed emulsions are formed when foams or aqueous surfactant solutions are used to clean up oil deteriorated surfaces, in the process of oil flotation of waste waters, in firefighting when the foam contacts various organic liquids and in the processes of chemical defoaming (foam destruction by antifoams). Individual foamed emulsions can have practical importance e.g. a foamed emulsion of bitumen is used in road coating foamed emulsions from liquid fuels are used as explosives. 

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