| 摘要 |
Methane reacts with steam and at least some carbon dioxide in a primary fuel conversion zone, the effluent from which is mixed with the effluent from a secondary fuel conversion zone, and the mixture is sent through a dewatering zone, a drying zone, and a zone in which the carbon monoxide product stream is separated from the dry recycle stream. Such recycle stream is sent to a divider so that, if desired, a portion of the recycle can be directed as a part of the total feed to the primary conversion zone, and at least some of the recycle stream plus at least some of the carbon dioxide feed is directed through a secondary fuel conversion zone, in which hydrogen and carbon dioxide react to form water and carbon monoxide. Ordinarily such a plant is built when the available supply of carbon dioxide is at least about 75% (molar) of the demand for carbon monoxide, and when minimization of methane consumption is desirable, so that under optimum conditions the overall net reaction is the oxidation of a mole of methane by three moles of carbon dioxide to produce four moles of carbon monoxide plus two moles of steam. The plant has flexibility of operation, so that carbon monoxide can be manufactured even when some supplies are curtailed. For example, sufficient recycle gas can be removed to prevent any build up of a component to a concentration which might be troublesome.
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