Kinetic model for liquid-phase liquefaction of asphaltene by hydrogenation with industrial distillate narrow fraction as hydrogen donor

Shen, Qiang; Wang, Gang; Zhang, Qiyuan; Gao, Chengdi; Duan, Mengchao; Gao, Jinsen

doi:10.1016/j.fuel.2017.07.078

Cited by 14 publications

(3 citation statements)

References 23 publications

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“…In this regard, a transfer of four atoms of hydrogen may be achieved by complete dehydrogenation of a tetralin molecule (Figure a), while the complete dehydrogenation of the saturated form of the monomer in SHTA renders 26 atoms of hydrogen (Figure b). In line with the function of hydrogen donor disclosed in the present study, various authors have consistently observed lowering of the amount of coke in thermal cracking of hydrocarbons when using hydrogen donors, − which is a consequence of the decrease of free-radical concentration yielding a slowdown of polymerization reactions that produce coke.…”

Section: Resultssupporting

confidence: 88%

Batch Reactor Study for Partial Upgrading of a Heavy Oil with a Novel Solid Hydrogen Transfer Agent

et al. 2020

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A novel solid hydrogen transfer agent (SHTA) based on an organic polymer containing fused-aromatic-ring units, supported in an inorganic matrix, was prepared and tested as a hydrogen donor in the upgrading of a heavy crude oil and its 274 and 343 °C+ residua. The SHTA performance is compared with that obtained using a conventional liquid hydrogen donor (tetralin). Three sets of experiments were carried out in a batch reactor: (1) hydrovisbreaking (HVB), (2) HVB with added tetralin, and (3) HVB with added SHTA. The results showed that the use of tetralin or SHTA in the HVB reaction enhances upgrading of heavy oils compared with the experiments without a hydrogen donor (HVB alone). Moreover, lower coke formation and a higher yield of liquid products were observed. The results obtained when using the novel SHTA are equivalent to those obtained when using tetralin as a hydrogen donor in the upgrading of a heavy crude oil and its 274 and 343 °C+ residua.

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Section: Resultssupporting

confidence: 88%

Batch Reactor Study for Partial Upgrading of a Heavy Oil with a Novel Solid Hydrogen Transfer Agent

et al. 2020

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“…Hydrogen transfer reactions are very important during thermal conversion of heavy oils, bitumen, and coals. In the literature, much emphasis was placed on hydrogen donors and hydrogen donor solvents. − The use of hydrogen donor solvents gave rise to the development of aptly named processes such as the Donor Refined Bitumen process, and the Exxon Donor Solvent process . A common feature of these liquefaction-type processes was the use of hydrogen donor solvents, which could be regenerated in situ or ex situ by hydrogenation.…”

Section: Introductionmentioning

confidence: 99%

Hydrogen Transfer in Asphaltenes and Bitumen at 250 °C

Payan

Klerk

2018

Energy Fuels

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Hydrogen transfer in asphaltenes and bitumen was studied at 250 °C. Use was made of dihydronaphthalene as probe molecule, which has both hydrogen donor and hydrogen acceptor properties. Tetralin and naphthalene, which are the products from hydrogen disproportionation of dihydronaphthalene, were unreactive as hydrogen donor and hydrogen acceptor in control reactions with asphaltenes. The asphaltenes fraction was a net hydrogen acceptor, whereas bitumen was a net hydrogen donor during prolonged conversion with dihydronaphthalene. The free radical content of asphaltenes and bitumen (of the order of 10 18 spins/g in the feed) changed during thermal conversion and dihydronaphthalene affected these changes only to a minor extent. In the case of bitumen, there was a decrease in the free radical content of the product irrespective of whether dihydronaphthalene was present or not. Yet, despite the presence of free radicals in asphaltenes and bitumen, the reaction rate of dihydronaphthalene was suppressed compared to the self-reaction of dihydronaphthalene. Dihydronaphthalene reacted by molecule-induced homolysis to produce free radical intermediates; the initial reaction rate was around 1.6 × 10 −3 mol•h −1 •g −1 . It was found that hydrogen donation by the free radical intermediates was faster than hydrogen abstraction, so that naphthalene was the most abundant product from self-reaction and that the heavier products formed by free radical addition were hydrogen enriched. Although formation of tetralin and naphthalene was thermodynamically favored, conversion was not equilibrium controlled and stoichiometric limitations were imposed by hydrogen disproportionation. Product selectivity during the self-reaction of dihydronaphthalene, and the decrease in reaction rate of dihydronaphthalene in the presence of free radical containing feed, both challenged the assumption that hydrogen abstraction by free radicals did not require activation energy. The work demonstrated that molecule-induced homolysis readily takes place at 250 °C and that oilsands derived asphaltenes and bitumen are reactive for hydrogen transfer at these conditions.

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“…Основные исследования, выполненные в этом направлении, посвящены превращениям А в процессах гидроочистки [2,3]. Число работ, связанных с поведением А при термическом крекинге, ограничено и касается, главным образом, процессов образования кокса [4] и развития кинетических моделей процесса [5]. Для характеристики состава и структуры А используют комплекс физико-химических методов, включающий элементный анализ, анализ металлов, гель-проникающую хроматографию, ИК и ЯМР спектроскопии, термолиз и флэш-пиролиз в широком интервале температур [6], а также методы, основанные на селективной химической деструкции связей С-S, C-O, С-С [7].…”

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Sostav i struktura produktov termicheskogo razlozheniya asfaltenov tyazheloy nefti

2018

Perspektivnye Materialy S Ierarkhicheskoy Strukturoy Dlya Novykh Tekhnologiy I Nadezhnykh Konstruktsiy» I «Khimiya Nefti I Gaza

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Kinetic model for liquid-phase liquefaction of asphaltene by hydrogenation with industrial distillate narrow fraction as hydrogen donor

Cited by 14 publications

References 23 publications

Batch Reactor Study for Partial Upgrading of a Heavy Oil with a Novel Solid Hydrogen Transfer Agent

Batch Reactor Study for Partial Upgrading of a Heavy Oil with a Novel Solid Hydrogen Transfer Agent

Hydrogen Transfer in Asphaltenes and Bitumen at 250 °C

Sostav i struktura produktov termicheskogo razlozheniya asfaltenov tyazheloy nefti

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