advances in fluid catalytic cracking

[...]... [1] Refiners are looking for technologies to raise the production of light cycle oil (LCO) from their fluid catalytic cracking unit (FCCU) to take advantage of the significant value of diesel relative to gasoline LCO, like gasoline, is an intermediate product whose yield increases with conversion at very low conversion levels, eventually reaching an overcracking point Past the overcracking point, LCO... recycle streams with boiling point range of 650°F–750°F obtained from VGO 4 Advances in Fluid Catalytic Cracking Table 1.1 Properties of VGO and Resid Used in the Study Feed Name Vacuum Gas Oil API gravity at 60°F Specific gravity at 60°F Refractive index K factor Aniline point, °F Average molecular weight Paraffinic ring carbons, wt.% Naphthenic ring carbons, wt.% Aromatic ring carbons, wt.% Sulfur,... diagram of the cracking path of a feed element in FCCU recycling operation recycling stream into the base feed Note that the interactions between the molecules from the recycling stream and those from the base feed during cracking complicate the interpretation of the incremental yield, and make it recycling ratio dependent For simplicity and because of the small range of recycling ratio in this study,... reside in boiling point range higher than 750°F, which is evident in Table 1.5 The molecular structure of all the aromatic hydrocarbons contains an aromatic core and some saturate side chains/rings The aromatic nucleus cannot be cracked in the FCC condition, and cracking reaction generally happens to the saturate side chains After cracking, most of the saturate side chains end up as wet gas (C4 and minus... paraffins are selectively cracked into gasoline and LCO, which favors VGO After product separation, HCO is recycled and fed into the unit again For feeds with more di-aromatics like resid, the following cracking pass efficiently upgrades di-aromatics in HCO into LCO Furthermore, comparing to gasoline mode, the recycling operation with low conversion minimizes the overcracking of LCO Feeds with less di-aromatics... fresh feed and R recycled stream from the first-pass cracking by weight fraction This second pass corresponds to the ACE study in our DCR + ACE scheme Analog to the partial molar properties in thermodynamics, we define the incremental yield of recycling stream as the change in normalized yield due to the addition of the 8 Advances in Fluid Catalytic Cracking Products Crude F C C F C C Recycle stream Products... the recycle ratio, defined as the fraction of the recycle stream in the total feed into the unit R is equal to 0.1 in the above example By accumulating the products along the path of this 100 gram feedstock, we can get the product yields as weight percentage on the 100 grams fresh feed basis Using this 6 Advances in Fluid Catalytic Cracking API gravity 20 12 15 8 10 4 5 0 Boiling point of 50 vol%, F 1000... maximum gasoline mode The feed rate relative to maximum gasoline mode subjected to the same operation constraints are listed as well 1.00 1.00 1.00 — Recycle Boiling Range Coke burn limited Wet gas limited Catalyst circulation limited 70 Conversion, wt% Table 1.6 (continued) Interpolated Yields of Base and Combined Feeds at 70% and 55% Conversion 14 Advances in Fluid Catalytic Cracking 15 Maximizing FCC... ACS meeting in Washington, DC in August 2009 As a result the present volume contains, in addition to research presented at the symposium, several invited papers To refiners, changes and challenges are everyday occurrences After overcoming oil supply limitations from Middle East politics and the obstacles of fuel reformulations and rising crude prices, the industry is now facing an evergrowing number... less carbon atoms and a boiling point less than 430°F, so they are the precursors of gasoline [7] Di-aromatic cores from the cracking, on the other hand, contain more carbon atoms and feature a higher boiling point These aromatic structures fall into the LCO boiling point range [7,8] Therefore, the higher di-aromatics level in the 650°F–750°F recycle stream of the resid explains its higher LCO yield (37.0% . identification and explanation without intent to infringe. Library of Congress Cataloging -in- Publication Data Advances in fluid catalytic cracking : testing, characterization, and environmental. alt="" Advances in Fluid Catalytic Cracking Testing, Characterization, and Environmental Regulations CHEMICAL INDUSTRIES A Series of Reference Books and Textbooks Founding Editor HEINZ HEINEMANN Berkeley,. gasoline, is an intermediate product whose yield increases with conversion at very low conversion levels, eventually reaching an overcracking point. Past the over- cracking point, LCO yield declines