500kg natural gas hydrogen production unit

Technological process

Natural gas compression and conversion

The natural gas outside the battery limit is first pressurized to 1.6Mpa by the compressor, then heated to about 380 ℃ by the feed gas preheater in the convection section of the steam reformer furnace, and enters the desulfurizer to remove the sulfur in the feed gas below 0.1ppm. The desulfurized feed gas and process steam (3.0mpaa) Adjust the mixed gas preheater according to the automatic value of H2O / ∑ C = 3 ~ 4, further preheat to more than 510 ℃, and evenly enter the conversion pipe from the upper gas gathering main pipe and upper pigtail pipe. In the catalyst layer, methane reacts with steam to generate CO and H2. The heat required for methane conversion is provided by the fuel mixture burned at the bottom burner. The temperature of the converted gas out of the reformer furnace is 850 ℃, and the high temperature is converted to high temperature。 The chemical gas enters the tube side of the waste heat boiler to produce 3.0mpaa saturated steam. The temperature of the conversion gas from the waste heat boiler drops to 300 ℃, and then the conversion gas enters the boiler feed water preheater, conversion gas water cooler and conversion gas water separator in turn to separate the condensate from the process condensate, and the process gas is sent to the PSA.

The natural gas as fuel is mixed with the pressure swing adsorption desorption gas, and then the fuel gas volume into the fuel gas preheater is adjusted according to the gas temperature at the outlet of the reformer furnace. After flow adjustment, the fuel gas enters the top burner for combustion to provide heat to the reformer furnace.

The desalted water is preheated by the desalted water preheater and boiler feed water preheater and enters the by-product steam of flue gas waste boiler and reforming gas waste boiler.

In order to make the boiler feed water meet the requirements, a small amount of phosphate solution and deoxidizer shall be added to improve the scaling and corrosion of boiler water. The drum shall continuously discharge part of boiler water to control the total dissolved solids of boiler water in the drum.

Pressure swing adsorption

PSA consists of five adsorption towers. One adsorption tower is in adsorption state at any time. The components such as methane, carbon dioxide and carbon monoxide in the conversion gas stay on the surface of the adsorbent. Hydrogen is collected from the top of the adsorption tower as non-adsorption components and sent out of the boundary. The adsorbent saturated by impurity components is desorbed from the adsorbent through the regeneration step. After being collected, it is sent to the reformer furnace as fuel. The regeneration steps of the adsorption tower are composed of 12 steps: first uniform drop, second uniform drop, third uniform drop, forward discharge, reverse discharge, flushing, third uniform rise, second uniform rise, first uniform rise and final rise. After regeneration, the adsorption tower is again capable of treating converted gas and producing hydrogen. The five adsorption towers take turns to carry out the above steps to ensure continuous treatment. The purpose of converting gas and continuously producing hydrogen at the same time.

Main process equipment