Catalytic Cracking Gas Research Articles

Extraction of gas oil from catalytic cracking

1) The main part (61.5–73.4%) of the total amount of aromatic compounds which are present in catalytic gas oils are polycyclic compounds. 2) The polycyclic aromatic compounds consist of both pure aromatic and of hydroaromatic hydrocarbons; no more than one naphthene ring being present in a molecule of the latter hydrocarbons. The number of caron atoms in the side chains is 1.3–2.4. 3) In comparison with phenol, furfurole has a higher selectivity with respect to the polycyclic aromatic compounds. 4) The dissolving capacity of the phenol is somewhat higher for phenol than for furfurole. 5) The temperature range for this extraction of catalytic cracking gas oil by furfurole is 1.5 times greater than for phenol. 6) The optimum furfurole flow rate for the extraction of catalytic cracking gas oil is 100% by volume based on the raw material.

Composition of bicyclic aromatic hydrocarbons in catalytic cracking gas oil

1. Sulfur-containing and hydropurified fractions of aromatic hydrocarbon extracts from light catalytic cracking gas oil have been studied by a combination of gas chromatography and molecular spectroscopy. The total composition of the C10-C12 naphthalene hydrocarbons has been determined, and also the content of some derivatives of the benzothiophene and tetralin series. 2. The relative contents of individual dimethylnaphthalenes are close to the same values for all products studied.

Hydrogen Blistering of Steel In Hydrogen Sulfide Solutions

Abstract Extensive damage to some refinery equipment has occurred owing to transmission through steel of the hydrogen formed during corrosion of steel by hydrogen sulfide solutions. Damage in the form of hydrogen blistering, fissuring and embrittlement of steel has been particularly severe in catalytic cracking gas plants. Laboratory investigations have been made of the relative influence of environmental factors on the rate and extent of hydrogen transmission through carbon steel. These studies include determination of the effects of concentration of important constituents such as hydrogen sulfide, low molecular weight organic acids, ammonia and hydrogen cyanide. Several other compounds were studied and found to be of minor importance. The laboratory method involved measurement of the volume of hydrogen which passed through to the opposite side of a thin wall of carbon steel. In certain hydrogen sulfide environments hydrogen transmission practically ceased after a short time. This behavior is ascribed to...

Thermofor Catalytic Cracking Gas Plant Corrosion Survey

Severe corrosion has been experienced in a Thermofor catalytic cracking gas plant over several years. Representative inspection findings are outlined. A complete chemical survey of gas plant streams for amount and type of corrosives, together with water present, is given. Ammonia and hydrogen sulfide are indicated the principal corrosives present. These have caused corrosion of overhead condensing equipment. Some ammonia acid salts are present which have dissociated at reboiler temperatures to give acid conditions which have caused rapid attack of reboiler tubes. Measures are suggested to remove water, which will also remove the principal corrosive constituents at appropriate points in the system. Possible places for chemical injection are suggested to neutralize any traces of remaining corrosives.