Methanol prepn from off-gases - by conversion with steam to synthesis gas, then treatment over a copper catalyst giving methanol

摘要

Off gas, e.g. from steel mfr, is freed from dust and cooled by a water spray, compressed by a steam driven turbocompressor to 30-80 atmos, treated with steam at 300-500 degrees C over a catalyst e.g. Fe oxide and the resulting synthesis gas washed with methanol e.g. at -40 degrees C. The purified synthesis gas is converted over a water cooled Cu catalyst at e.g. 250 degrees C and 46 atmos. to methanol. Steam raised from water used to cool the Cu catalyst is combined with steam for an auxiliary boiler fueled with synthesis purge gas and off-gas, and drives the off-gas compressor. The process converts an otherwise useless by product of steel mfr. to methanol with small energy expenditure.