Process design, exergy, and economic assessment of a conceptual mobile autothermal methane pyrolysis unit for onsite hydrogen production

•A conceptual mobile autothermal methane pyrolysis unit for onsite hydrogen production was proposed.•The design combines methane pyrolysis and char gasification in an energy efficient way.•The levelized cost of hydrogen (LCOH) obtained from the conceptual design ranged from 1.3 to 1.47 U.S.$/kg.•The proposed design’s net present value (NPV) was in the range of 3.76 – 4.35 M.U.S.$.•Compared to onsite hydrogen production, the mobile design is profitable.