LNG fuel cell energy supply and cold energy utilization zero carbon emission system and method

The invention discloses an LNG fuel cell energy supply and cold energy utilization zero-carbon emission system and method. The system comprises an LNG storage tank, a cold box, a steam generation device, a natural gas steam reforming device and a high-temperature fuel cell power generation and energy supply device. The LNG storage tank is connected with the cold box; the cold box is connected with the natural gas steam reforming device, and the steam generating device is connected with the natural gas steam reforming device; the high-temperature fuel cell power generation and energy supply device comprises a high-temperature solid oxide fuel cell, a combustor and a carbon dioxide separation device, the natural gas steam reforming device is connected with the anode of the fuel cell, the anode of the fuel cell is connected with the combustor, the cathode of the fuel cell is connected with the combustor through a first branch, and the combustor is connected with the carbon dioxide separation device; the carbon d