Suppression of sludge formation by two-stage hydrocracking of vacuum residue at high conversion

Journal Article · Sat Dec 01 00:00:00 EST 1990 · Industrial and Engineering Chemistry Research; (United States)

DOI:https://doi.org/10.1021/ie00108a003· OSTI ID:5571889

Mochida, I; Zhao, X; Sakanishi, K ^[1]

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1. Inst. of Advanced Material Study, Kyushu Univ., Kasuga, Fukuoka 816 (JP)

This paper reports on hydrocracked products from Arabian light vacuum residue at high conversion into distillate ({gt}50%) that were analyzed in order to reveal how sludge formation was suppressed in the two-stage reaction. Although the asphaltene in the starting residue was highly soluble in the starting maltene in spite of is largest molecular weight, single-stage hydrocracking at a higher temperature of 420{degrees}C increased the aromaticity of the asphaltene through extensive deaklylation and dehydrogenation, leading to sludge formation. In contrast, two-stage hydrocracking at 390{degrees}C--3 h/420{degrees}C--1/h accomplished effective depolymerization of the asphaltene, high conversion being achieved without sludge. The carbon aromaticity (f{sub a}) of the produced asphaltene was maintained rather low, although its amount in the product was much the same regardless of the reaction conditions. The heptane-soluble maltenes in the hydrocracked oils exhibited variable dissolving abilities against the asphaltene according to the content and aromaticity of its aromatic fraction, also influencing sludge formation. Hydrocracking produced paraffins through the hydrogenative deaklylation of long-chain alkylbenzenes, decreasing f{sub a} and the dissolving ability of the hydrocracked maltene.

• OSTI ID: 5571889
• Journal Information: Industrial and Engineering Chemistry Research; (United States), Vol. 29:12, Issue 12; ISSN 0888-5885
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
PETROLEUM DISTILLATES
CHEMICAL COMPOSITION
PETROLEUM RESIDUES
HYDROCRACKING
WASTES
MINIMIZATION
ASPHALTENES
BY-PRODUCTS
ENERGY CONVERSION
ASPHALTS
BITUMENS
CHEMICAL REACTIONS
CONVERSION
CRACKING
DECOMPOSITION
DISTILLATES
ENERGY SOURCES
FOSSIL FUELS
FUELS
ORGANIC COMPOUNDS
OTHER ORGANIC COMPOUNDS
PETROLEUM
PETROLEUM FRACTIONS
PYROLYSIS
TAR
THERMOCHEMICAL PROCESSES
020400* - Petroleum- Processing
020500 - Petroleum- Products & By-Products
023000 - Petroleum- Properties & Composition