Method and plant for the production of methanol

A method for converting an existing plant for the production of methanol from an operation with synthesis gas low in inerts to an operation with synthesis gas rich in inerts, the method comprising:

• providing a plant that performs a method including:
• (a) passing a synthesis gas low in inerts and including carbon oxides and hydrogen through at least one synthesis reactor so as to catalytically convert a part of the carbon oxides to methanol and so as to obtain a first mixture including synthesis gas, inert components and methanol vapor;
• (b) separating the methanol from the obtained first mixture so as to form a second mixture liberated from the methanol;
• (c) separating the second mixture into a cycle stream and a purge stream;
• (d) recirculating the cycle stream so as to form a synthesis circle;
• (e) combining the cycle stream with a fresh gas stream including hydrogen and carbon oxides before charging the cycle stream into the at least one synthesis reactor;
• providing a secondary reactor, outside of the synthesis circle, downstream of the purge stream so as to catalytically convert a further part of the hydrogen and carbon oxides to further methanol and obtain a third mixture;
• separating the further methanol from the third mixture;
• and
• operating the plant with a synthesis gas rich in inerts and reducing a ratio of the recirculated synthesis gas stream to fresh gas stream compared to the existing method.