Co-production of methanol, ammonia and urea

A plant for co-producing methanol, ammonia and urea from a hydrocarbon feedstock, comprising:

• a first methanol process line for carrying out a first reforming step and a first methanol conversion step to obtain a first effluent comprising methanol and a first gas effluent comprising hydrogen, nitrogen and unconverted carbon oxides;
• a second methanol process line for carrying out a second reforming step and a second methanol conversion step to obtain a second effluent comprising methanol and a second gas effluent comprising hydrogen, nitrogen and unconverted carbon oxides;
• an interconnecting synthesis line allowing fluid communication between the first and second methanol process lines, allowing a methanol synthesis gas from each of the two first and second reforming steps to be distributed to each of the first and second methanol conversion steps;
• a catalytic methanation stage for producing ammonia synthesis gas from the first gas effluent and the second gas effluent, the ammonia synthesis gas having a H2:N2 molar ratio of approximately 3:1;
• an ammonia synthesis stage for catalytically converting the nitrogen and hydrogen of the ammonia synthesis gas to produce an effluent comprising ammonia and a purge-gas stream comprising hydrogen, nitrogen and/or methane;
• and
• a urea plant for reacting at least part of the effluent comprising ammonia with at least part of a flue gas comprising CO2 from at least one of the first and second reforming steps to produce urea;
• wherein the first reforming step of the first methanol process line and the second reforming step of the second methanol process line are each carried out in a respective primary reforming stage and a respective secondary reforming stage, wherein the hydrocarbon feedstock is steam reformed in the respective primary reforming stage to obtain a partially reformed gas and the partially reformed gas is then further reformed under addition of air in the respective secondary reforming stage to obtain the methanol synthesis gas.