Thermodynamic analyses of hydrogen production from sub-quality natural gas - Part I: Pyrolysis and autothermal pyrolysis

    Authors

    C. P. Huang;A. T-Raissi

    Comments

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    Abbreviated Journal Title

    J. Power Sources

    Keywords

    hydrogen; natural gas; sub-quality natural gas; thermodynamic analysis; hydrogen sulfide; sulfur dioxide; carbon disulfide and methane; ELECTROCHEMICAL REMOVAL; SULFIDE; SULFUR; Electrochemistry; Energy & Fuels

    Abstract

    Sub-quality natural gas (SQNG) is defined as natural gas whose composition exceeds pipeline specifications of nitrogen, carbon dioxide (CO2) and/or hydrogen sulfide (H2S). Approximately one-third of the U.S. natural gas resource is sub-quality gas [1]. Due to the high cost of removing H2S from hydrocarbons using current processing technologies, SQNG wells are often capped and the gas remains in the ground. We propose and analyze a two-step hydrogen production scheme using SQNG as feedstock. The first step of the process involves hydrocarbon processing (via steam-methane reformation, autothermal steam-methane reformation, pyrolysis and autothermal pyrolysis) in the presence of H2S. Our analyses reveal that H2S existing in SQNG is stable and can be considered as an inert gas. No sulfur dioxide (SO2) and/or sulfur trioxide (SO3) is formed from the introduction of oxygen to SQNG. In the second step, after the separation of hydrogen from the main stream, un-reacted H2S is used to reform the remaining methane, generating more hydrogen and carbon disulfide (CS2). Thermodynamic analyses on SQNG feedstock containing up to 10% (v/v) H2S have shown that no H2S separation is required in this process. The Part I of this paper includes only thermodynamic analyses for SQNG pyrolysis and autothermal pyrolysis. (c) 2006 Elsevier B.V. All rights reserved.

    Journal Title

    Journal of Power Sources

    Volume

    163

    Issue/Number

    2

    Publication Date

    1-1-2007

    Document Type

    Article; Proceedings Paper

    Language

    English

    First Page

    645

    Last Page

    652

    WOS Identifier

    WOS:000243650800004

    ISSN

    0378-7753

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