Process for start-up of an autothermal reformer

A process for the start-up of an autothermal reformer, the autothermal reformer comprising an autothermal reformer reactor with a burner, the process comprising:

• heating an inert gas by an inert gas heating means, and introducing the heated inert gas in a circulation loop containing the autothermal reformer reactor;
• heating a mixture of inert gas and process steam by a mixture heating means, and introducing the heated mixture of inert gas and process steam in the circulation loop containing the autothermal reformer reactor;
• introducing heated process steam in the circulation loop as soon as a minimum outlet threshold temperature of the autothermal reformer reactor is reached, wherein inert gas is removed from the circulation loop;
• heating a hydrocarbon containing process stream by a hydrocarbon stream heating means, and introducing the heated hydrocarbon containing process stream into the autothermal reformer reactor, whereby a syngas stream containing carbon oxides and hydrogen is produced in the autothermal reformer reactor through steam reforming;
• cooling the produced syngas stream to separate water from the syngas stream as process condensate, whereby a dry syngas stream is obtained;
• recycling a fraction of the dry syngas stream from a downstream section of the autothermal reformer reactor to an upstream section of the autothermal reformer reactor;
• whereby
• a mixed process stream is obtained at the upstream section of the autothermal reformer reactor, the mixed process stream containing the process steam, the hydrocarbon containing process stream and the recycled dry syngas stream;
• introducing the mixed process stream to the burner of the autothermal reformer reactor;
• introducing an oxygen containing process stream to the burner of the autothermal reformer reactor as soon as a minimum hydrogen threshold concentration in the mixed process stream at the upstream section of the autothermal reformer reactor is reached;
• whereby
• autoignition of the mixed process stream is obtained;
• and
• operating the autothermal reformer to produce syngas through autothermal reforming.