China Small and Medium Size Air Separation Unit Industrial Liquid Oxygen Plant Liquid Nitrogen Plant,
China Liquid Air Separation Plant, Liquid Oxygen Nitrogen Equipment,
Technical proposal
1.Main parameters of the device
1.1Design conditions
Raw material name: natural gas
Raw material pressure: 0.02mpag (gauge pressure)
Raw material temperature: ambient temperature
Raw material composition (Provisional)
| Mole Frac | |
| H2S | 20PPM |
| N2 | 1.795 |
| CO2 | 0.562 |
| CH4 | 92.887 |
| C2H6 | 3.705 |
| C3H8 | 0.679 |
1.2Technical requirements for product hydrogen
Production capacity: 235nm3 / h (500kg / D)
Hydrogen purity: H2 ≥ 99.9%
Natural gas consumption: 110m3 / h (LHV greater than 8500Kcal / m3)
Hydrogen output pressure: ≥ 1.6Mpa
Outlet temperature: ≤ 40 ℃
1.3Performance guarantee
l Mean time between failures of power equipment 8000 hours
l Device operation flexibility: 30 ~ 110%
l The design life of static equipment is 15 years
1.4General layout
The outdoor device layout area is 26mx10m = 260m2
2. Process unit
2.1technological 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, 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 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. After flow adjustment, the fuel gas enters the top burner for combustion to provide heat to the reformer.
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.
l 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 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.
2.2 Main process equipment
| Serial number | Equipment name | Main specifications | Main materials | Unit weight ton | quantity | remarks |
| I | Natural gas steam conversion section | |||||
| 1 | Reformer | 1 set | ||||
| thermal load | Radiation section: 0.6mW | |||||
| Convection section: 0.4mw | ||||||
| Burner | Heat load: 1.5mw/set | compound material | 1 | |||
| High temperature reformer tube | HP-Nb | |||||
| Upper pigtail | 304SS | 1 set | ||||
| Lower pigtail | Incoloy | 1 set | ||||
| Convection section heat exchanger | ||||||
| Preheating of mixed raw materials | 304SS | 1 group | ||||
| Feed gas preheating | 15CrMo | 1 group | ||||
| Flue gas waste boiler | 15CrMo | 1 group | ||||
| Manifold | Incoloy | 1 group | ||||
| 2 | chimney | DN300 H=7000 | 20# | 1 | ||
| Design temperature: 300 ℃ | ||||||
| Design pressure: ambient pressure | ||||||
| 3 | Desulfurization tower | Φ400 H＝2000 | 15CrMo | 1 | ||
| Design temperature: 400 ℃ | ||||||
| Design pressure: 2.0MPa | ||||||
| 4 | Conversion gas waste boiler | Φ200/Φ400 H＝3000 | 15CrMo | 1 | ||
| Design temperature: 900 ℃ / 300 ℃ | ||||||
| Design pressure: 2.0MPa | ||||||
| Heat load: 0.3mw | ||||||
| Hot side: high temperature conversion gas | ||||||
| Cold side: boiler water | ||||||
| 5 | Boiler feed pump | Q=1m3/h | 1Cr13 | 2 | 1+1 | |
| Design temperature: 80 ℃ | ||||||
| Inlet pressure: 0.01Mpa | ||||||
| Outlet pressure: 3.0MPa | ||||||
| Explosion proof motor: 5.5kw | ||||||
| 6 | Boiler feed water preheater | Q=0.15MW | 304SS/20R | 1 | Hairpin | |
| Design temperature: 300 ℃ | ||||||
| Design pressure: 2.0MPa | ||||||
| Hot side: conversion gas | ||||||
| Cold side: desalted water | ||||||
| 7 | Reforming gas water cooler | Q=0.15MW | 304SS/20R | 1 | ||
| Design temperature: 180 ℃ | ||||||
| Design pressure: 2.0MPa | ||||||
| Hot side: conversion gas | ||||||
| Cold side: circulating cooling water | ||||||
| 8 | Reforming gas water separator | Φ300 H＝1300 | 16MnR | 1 | ||
| Design temperature: 80 ℃ | ||||||
| Design pressure: 2.0MPa | ||||||
| Demister: 304SS | ||||||
| 9 | Dosing System | phosphate | Q235 | 1 set | ||
| Deoxidizer | ||||||
| 10 | Desalination tank | Φ1200 H＝1200 | Q235 | 1 | ||
| Design temperature: 80 ℃ | ||||||
| Design pressure: ambient pressure | ||||||
| 11 | Natural gas compressor | Exhaust volume: 220m3 / h | ||||
| Suction pressure: 0.02mpag | ||||||
| Exhaust pressure: 1.7mpag | ||||||
| Oil free lubrication | ||||||
| Explosion proof motor | ||||||
| Motor power: 30KW | ||||||
| 12 | Natural gas buffer tank | Φ300 H＝1000 | 16MnR | 1 | ||
| Design temperature: 80 ℃ | ||||||
| Design pressure: 0.6MPa | ||||||
| II | PSA part | |||||
| 1 | Adsorption tower | DN700 H=4000 | 16MnR | 5 | ||
| Design temperature: 80 ℃ | ||||||
| Design pressure: 2.0MPa | ||||||
| 2 | Desorption gas buffer tank | DN2200 H=10000 | 20R | 1 | ||
| Design temperature: 80 ℃ | ||||||
| Design pressure: 0.2MPa |
2.3 Main consumption table
| ordernumber | Utilities and industrializationLearning products |
Specifications |
Company | consume |
remarks |
| 1 | electric | 220V/380V 50Hz | KW | 40 | Pumps, instruments, compressors |
| 2 | Desalted water | Pressure: 0.2 ~ 0.3MPa | kg/h | 800 | |
| Conductivity: < 10us / cm | |||||
| SiO2:<10ppb | |||||
| Residual chlorine: < 0.5ppb | |||||
| Na+:<0.5ppm | |||||
| 3 | Instrument air | 0.4~0.6Mpa | m3/h | 100 | |
| Dry and oil-free | |||||
| Dew point lower than – 5 ℃ | |||||
| 4 | Circulating cooling water | Water feeding temperature: 32 ℃ | t/h | 30 | ∆T=10℃ |
| Return water temperature: 42 ℃ | |||||
| Water feeding pressure: 0.3 ~ 0.4MPa | |||||
| Fouling coefficient: 0.0004m2k/w | Design value | ||||
| PH value: 7.5 ~ 8.5 | |||||
| CL-：<100ppm |
China Small and Medium Size Air Separation Unit Industrial Liquid Oxygen Plant Liquid Nitrogen Plant,
China Liquid Air Separation Plant, Liquid Oxygen Nitrogen Equipment,
