FIELD: gas synthesis.
SUBSTANCE: invention relates to a method for the synthesis of methanol (1). In this method, a stream (11) of a carbonaceous energy carrier is fed into the gas synthesis reactor unit (13) to obtain a synthesis gas stream (2) containing hydrogen and carbon oxides. Next, the synthesis gas stream (2) is fed to the first stage (21a) of the methanol synthesis reactor unit (4) for partial conversion into methanol (1), while the synthesis gas stream (2) obtained in the gas synthesis reactor unit (13), has, when formed, a higher pressure than the synthesis pressure at which the synthesis gas stream (2) in the first stage (21a) of the reactor is partially converted to methanol (1). Moreover, in the reactor unit (4) for the synthesis of methanol, a residual gas stream (15) containing unreacted carbon oxides is obtained. Further, the tail gas stream (15) is fed to the recirculation compressor (14) in order to increase the pressure of the tail gas stream (15), while the pressurized tail gas stream (15) is fed to the methanol synthesis reactor unit (4) for partial conversion into methanol. Before being fed to the first stage (21a) of the reactor, the synthesis gas stream (2) is fed into the heat recovery device (10) to remove the heat of the synthesis gas stream (2), while the exhaust stream (6) containing unreacted hydrogen from the unreacted residual gas (16a) of the first stage (21a) of the reactor is fed into the hydrogen recovery unit (5) to obtain a recycled H stream (7) containing unreacted hydrogen of the effluent stream (6), and again the unreacted hydrogen of the bleed stream (6) is fed to the first stage (21a) a reactor for the purpose of at least partial conversion into methanol (1). Moreover, the pressure of unreacted hydrogen of the discharge stream (6) of the first stage (21a) of the reactor before returning to the first stage (21a) of the reactor is increased only once using a recirculation compressor (14) together with unreacted carbon oxides. The invention also relates to a corresponding methanol synthesis plant (1).
EFFECT: improvement and further development of the methanol synthesis method known from the prior art without a synthesis gas compressor and the methanol synthesis plant known from the prior art without a synthesis gas compressor, in which a separate compressor for returning hydrogen is not required, and the recirculation compressor may have smaller size.
15 cl, 5 dwg
