Pressure Electrolysis based / Methanol Reforming Based / Ammonia Cracking Based
The hydrogen generator offered here is based on Bipolar Pressurized Water Electrolysis Based System. The Electrolyser can be operated from 10 - 32barg. Each electrolyser is designed for a capacity 10 % extra of desired final hydrogen flow; this is to take care of 10 % loss of hydrogen in Purification system after hydrogen is generated.
The Main equipment of hydrogen generator is electrolyser, in which, water is decomposed into hydrogen and oxygen through electrolysis, the equation is 2H2O == O2+2H2
• The electrolyser is bipolar pressurized type
• The cell of electrolyser is divided into anode cell and cathode cell
• Hydrogen is generated in cathode side
• Oxygen is generated in anode side
• Electrolyser is filled with electrolyte KOH mixed with DM water (30% KOH).
• On Electrical Side Rectifying transformer is used to change high AC voltage electricity to low voltage electricity and then through rectifying to become DC power.
• The positive pole of DC power is connected to the anode of electrolyser, cathode of electrolyser directly comes from transformer.
• Rectifying transformer and rectifier are two main part of Electric power supply unit.
• Cathodic reaction is 4H2O+4e == 2H2+4OH-
• Anodic reaction is 4OH == O2+2H2O+4e-
• The pressure of the system is raised to and maintained at the set pressure by means of regulating valve.
• The electrolyte at the bottom of hydrogen and oxygen separators is pumped back to electrolyser after filtering and cooling, to complete one process cycle.
• Hydrogen & oxygen generated in electrolyser mixed with electrolyte are sent to
Hydrogen and oxygen separators, there hydrogen and oxygen are separated with
electrolyte due to gravity.
• Hydrogen and oxygen gases are allowed to pass through hydrogen and oxygen coolers separately and are cooled to the temperature of 30~40°C,
• The hydrogen is allowed to pass through a pd deoxo unit and hydrogen dryer to remove its moisture and oxygen .
• Electrolyte tank is used for storing electrolyte and feed water.
• Electrolyte making pump has three functions
a. making the electrolyte
b. pumping electrolyte into system
c. Pumping electrolyte back to electrolyte tank.
• Feed water pump is a piston pump; it used to pressurize feed water into system.
Electrical equipment in the system have a high importance in the this hydrogen plant and as said above it have.
• Transformer & Rectifier
• The transformer changes the voltage from AC 415 V to the low voltage value required
• Rectifier Changes the Low voltage to DC Current to be supplied to electrolyser.
• The capacity of rectifying transformer is designed as per the size of electrolyser.
• At the input of rectifying transformer, a current and voltage measurement is provided with interlocks to protect the system in case of some malfunctions.
• Rectifying component includes rectifying components, control with interlocks.
• Rectifier function is to stabilization of current and voltage
• The voltage can be regulated from 0.6~1.05 times of the rated voltage
• The rated current of rectifier is 1.1 times of the rated current of electrolyser.
There are following indication and interlocks for safety and for better operation and control and regulation.
• DC voltage indication
• Current indication
• Current overflow indication
• Phase lack indication
• Cooling water malfunction
• High temperature of SCR
Power distribution panel (PMCC) is used to distribute incoming power to all electrical consumption points.
Hydrogen Compressor – An Oil Free Diaphragm type Hydrogen compressor is used to boost the pressure of purified hydrogen to required pressure of 150 BarG for Cylinder filling. The booster Compressor is supplied with associated accessories suction pot, hydrogen manifold etc.
