| 摘要 |
Natural gas hydrocarbon components methane to butanes are converted into low-vapor-pressure liquid hydrocarbons in a combination process which comprises successively passing the heavier fraction (C2 to C4) and the lighter fraction (C1, C2) with hydrogen over a non silica-based catalyst including crystals of basic mixed oxides and recovering C5+ hydrocarbons. First the heavier fraction of the feed (C2+) is converted at temperatures below 600<o>C over a fluidized or moving catalytic bed. Condensible C3+ products are fractionated for C5+ recovery and for C3, C4 recycling. Gas by-products H2, C1, C2 are separated into an enriched hydrogen stream and into a C1, C2 by-product gas which is recycled into the lighter fraction C1, C2 of the feed. The resulting lean gas mixture is then reacted with an ionized hydrogen plasma derived from the enriched hydrogen stream, in the presence of the same catalyst in a short residence time reactor. Liquified Natural Gas (LNG) is re-vaporized by heat exchange and pre-heated in a furnace at a temperature not exceeding 1100<o>C. It is fed, together with an ionized hydrogen plasma stream, into a reactor containing the same catalyst and the products are separated. These processes are of particular interest where natural gas has a relatively low market value. |
