Electrolyser

    The key equipment of hydrogen generator is electrolyser, in it, water is decomposed into hydrogen and oxygen through electrolysis, the equation is 2H2O==2 H2+O2

    The structure of electrolyser is bipolar press type, the cell of electrolyser is divided into anode cell and cathode cell. Electrolyser is full of electrolyte (30% KOH). Hydrogen is generated in cathode side, Cathodic reaction: 4H2O+4e == 2H2+4OH-

    The hydrogen generated in cathodic cell and its electrolyte is sent to hydrogen separator in auxiliary equipment frame, there hydrogen is separated with electrolyte under the action of gravity, then hydrogen passes through hydrogen cooler and is cooled to the temperature of 30~425℃, later hydrogen gas passes though the hydrogen demister to remove water, its pressure is raised to the set value by means of pneumatic regulation valve. The electrolyte at the bottom of hydrogen separator is pumped out and flows though lye filter and lye cooler, at last returns to the electrolyser again, the circle of hydrogen side electrolyte finished.

Oxygen is generated in anode side.

Anodic reaction: 4OH- == O2+2H2O+4e

    Oxygen and electrolyte from anode side are pumped into oxygen separator, there oxygen separates with electrolyte under the action of gravity, then oxygen passes through oxygen cooler, be cooled to the temperature of 30~425℃, where after it passes through oxygen demister to remove liquid water from gas. The electrolyte at the bottom of oxygen separator is pumped back to oxygen side cell of the electrolyser after filtering and cooling, oxygen side circulation is finished.

Description of the System

    According to the capacity and work pressure of hydrogen generator, the handling capacity of hydrogen purifier is determined. In order to guarantee the quality of hydrogen after purification, we use purified hydrogen as regeneration gas.

    The total system includes hydrogen generator, hydrogen purifier, electrical and control unit as well as a hydrogen buffer tank and a storage container.In this unit, water is decomposed into hydrogen and oxygen through electrolysis, the equation is

2H2O==2 H2+O2.

    Hydrogen, oxygen and electrolyte are sent to hydrogen and oxygen separators installed in auxiliary equipment frame, there hydrogen and oxygen are separated with electrolyte under the action of gravity, hydrogen and oxygen gases pass through hydrogen and oxygen coolers separately and are cooled to the temperature of 30~425℃, then pass through hydrogen and oxygen demisters to remove liquefied water from gases, then hydrogen and oxygen are supplied out. The pressure of the system is raised to and maintained at the set pressure by means of regulation valve. The electrolyte at the bottom of hydrogen and oxygen separators is pumped back to electrolyser after filtering and cooling, then, one circle is finished.

    The hydrogen from water electrolysis has the advantages of high purity and simple composition, normally only has the impurities like oxygen and water, it is easy to purify it to much higher purity used in electronic industry.

    There is a hydrogen buffer tank between hydrogen generator and hydrogen purification equipment; it is used to remove dissociative water from hydrogen and to keep the pressure of hydrogen purification unit stable. Hydrogen flows into purifier though this buffer. The action of purification equipment is to purify the hydrogen generated by hydrogen generator. The oxygen is removed though chemical reaction under the action of catalyst, and water is removed by the way of adsorption.

More information on the electrolyser can be found here.