Cracking residues

Influence of the feed coke produced from distillation residue is less structured, less crystalline than that from a cracking residue. If the residue feeding the unit is highly contaminated with sulfur and metals, it is still coke, but is disqualified for certain applications. 

In mice skin-painting studies, skin tumors were produced by steam-refined petroleum bitumens, an air-refined bitumen in toluene, two cracking residue bimmens, and a pooled mixmre of steam- and air-blown petroleum bitumens. In contrast, standard roofing petroleum asphalts produced no tumors. 

In response to recent federal and local environmental concerns (e.g., industrial emission controls and lead phase-out) and to the growing interest of refiners in cracking residual fuels, researchers have generated new families of cracking catalysts. There is now a need to review the merits of these newly developed materials. This volume contains contributions from researchers involved in the preparation and characterization of cracking catalysts. Other important aspects of fluid catalytic cracking, such as feedstocks and process hardware effects in refining, have been intentionally omitted because of time limitations and should be treated separately in future volumes. 

HVG0/DA0 - Heavy VG0, Wash oils - Deep Flashed VG0 - Flashed Cracked residues - Deasphalted Oil - Cutting deeper into the barrel, while trying to avoid excessive asphalthenes and metals... 

RFCC [Residual Fluid Catalytic Cracking] A process for cracking residues from petroleum distillation. It uses an ultrastable zeolite catalyst with two-stage regeneration. Originally developed in the early 1980s by Total Petroleum in Kansas and Oklahoma under the name R2R. Further developed by IFP with Stone and Webster and now more commonly known as RFCC. Twenty-six units had been licensed by 2003. 

AGIPIGCC Sannazzaro, Italy Shell 2005 Cracked residue (1200 mt/d) Fire-tube boiler 3.34 Power, H2... 

Most Gasification Most, Czech Republic Shell January 1971 Cracked residue (1250 mt/d) Fire-tube boiler 3.6 H2, methanol, power, steam... 

The heavy metal and chlorine contents seem to be lower in the thermal cracking residue. They are expected to remain higher in the dehydrochlorination residue, since they are fixed in it as inorganic chlorides. 

Refenring to our previous study perfonned on polycrystalline platinum, no blocking of the reaction appeared (fig. I) and no cracking product was issued from the reaction that is in agreement with the above discussion according to which the poisoning of the surface is due to cracking residues and not to the reacbon products themselves. 

Cracked residue is not solid coke but pitch. It makes the operation site clean and compact compared to other Coking processes, because pitch is handled as liquid in the process. 

The cracked products from both the ovens are directed to the reaction tower Tl. The mixture of vapor and liquid from T1 passes to the high-pressure evaporator T2. In T2 the cracking residue is separated from the vapor. This residue passes to the low-pressure evaporator T4, and is partly evaporated. The evaporator T4 has a blind tray in the middle section similar to that of tower T3. The vapor product (heavy gas oil) is partly condensed in the upper section of T4 and mixed with the fresh feed. The non-condensed part leaves the cracking unit as kerosene - gas oil fraction 2. 

The last product of the thermal cracking unit is the cracking residue 5, the bottom product of the low-pressure evaporator T4. 

Coking is used for the conversion of crude oil vacuum residues and cracking residues into coke and a clean liquid product with a high H/C ratio. Typical products of coking are hydrocarbon gas, naphtha, gas oil, feed oil for downstream processing and coke. 

Direct Contact. There are several processes at various stages of development for conversion of heavy feedstocks to ethylene. These use various heat carriers and thereby avoid the problem of coke deposition in tubes which can be associated with thermally cracking residues by the more conventional route. This type of process is characterized by the use of moving beds, fluid beds, or gaseous heat carriers. Typical of these processes are the developments of Hoechst, Lurgi, BASF, Unde, etc. (4, 6). 

Application To produce polymer-grade ethylene and propylene by thermally cracking hydrocarbon feedstocks (ethane through hydro-cracked residue). Shaw s key process technologies are ... 

Carbon deposition occurs when EUV photons crack residual hydrocarbons in the vicinity of an EUV optic or reticle. These hydrocarbons may originate from a number of sources such as outgassing of resists or other materials inside the scanner environment, residual air in the exposure chamber, etc. Once deposited, these carbon deposits can be cleaned with minimal or no damage to the underlying multilayer film. This could allow repeated cleaning cycles to be performed to extend the lifetime of an optics system. In this scenario, the frequency and duration of the cleaning procedure could be integrated into the operation of the tool in such a way that acceptable productivity and cost of ownership are maintained. ... 

Use of the Bloch and Hohn suction device to remove the cracking residue is not recommended since the residue solidifies easily in the narrow tubes and is then difficult to remove. 

Bitumens [8052-42-4], steam-refined, cracking-residue and air-refined (Vol. 35, Suppl. 7 1987)... 

The feedstock for the SGP unit is a heavy, vacuum-flashed cracked residue from an existing visbreaker unit. This material is typically characterized by high viscosity and high metal content. 

The Dubbs process (5) was a continuous thermal cracking process in which a relatively clean feedstock was cracked in furnace tubes with the continuous removal of heavy cracked residue from the system. This process was patented (1,049,667) in 1913. 

Manufacture of high-value coke (premium coke) with simultaneous production of minor amounts of liquid and gaseous hydrocarbons, i.e. the production of premium coke from highly-aromatic residues (coal-tar pitch, pyrolysis residues from naphtha cracking, residues from thermal and catalytic cracking). 

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