| abstract |
The invention relates to a process for workup of a stream ( 1 ) comprising butene and/or butadiene, butane, hydrogen and/or nitrogen and carbon dioxide, comprising:n (a) absorption of stream ( 1 ) with a mixture ( 5 ) comprising 80 to 97% by weight of N-methylpyrrolidone and 3 to 20% by weight of water to obtain a stream ( 9 ) comprising N-methylpyrrolidone, water, butene and/or butadiene, butane, and optionally carbon dioxide, and a stream ( 7 ) comprising hydrogen and/or nitrogen and butane, (b) extractive distillation of stream ( 9 ) with a stream ( 13 ) comprising 80 to 97% by weight of N-methylpyrrolidone and 3 to 20% by weight of water to separate the stream ( 9 ) into a stream ( 17 ) comprising N-methylpyrrolidone, water, butene and/or butadiene, and a stream ( 15 ) comprising essentially butane, and optionally carbon dioxide, (c) distillation of stream ( 17 ) into a stream ( 23 ) comprising essentially N-methylpyrrolidone and water, and a stream ( 21 ) comprising butene and/or butadiene. |