20-04-2012, 02:11 PM
Summary of Electrolytic Hydrogen Production
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Introduction
The purpose of this report is to give an overview of the current state of electrolytic hydrogen production technologies, and to provide an economic analysis of the processes. The study focuses on five companies’ current electrolyzer lines: Stuart IMET; Teledyne HM and EC; Proton HOGEN; Norsk Hydro HPE and Atmospheric; and Avalence Hydrofiller. The report details the state of technology as of December 2003 for all five companies’ electrolysis units, and then analyzes the economics of three standard sized electrolysis processes.
Analysis Methodology
The technical details for each company’s electrolysis systems were obtained from research on the Internet, and from personal conversations with industry representatives. The data presented are representative of systems available in December 2003. A detailed summary of each electrolysis model included in this study can be found in Appendix A.
For purposes of the analysis, the available electrolysis systems were categorized into five different size ranges: home, small neighborhood, neighborhood, small forecourt and forecourt. The term forecourt refers to a refueling station. The number of cars served and hydrogen production rate for each size are as follows:
• The home size will serve the fuel needs of 1- 5 cars with a hydrogen production rate of 200-1000 kg H2/year.
• The small neighborhood size will serve the fuel needs of 5-50 cars with a hydrogen production rate of 1000-10,000 kg H2/year.
• The neighborhood size will serve the fuel needs of 50-150 cars with a hydrogen production rate of 10,000 – 30,000 kg H2/year.
• The small forecourt size, which could be a single hydrogen pump at an existing station, will serve 150 – 500 cars with a hydrogen production rate of 30,000 – 100,000 kg H2/year.
• A full hydrogen forecourt will serve more then 500 cars per year with a hydrogen production rate of greater then 100,000 kg H2/year.
The number of cars served was determined by calculating that a car requires approximately 200 kg of hydrogen per year. This 200 kg requirement assumes that on average a car travels 12,000 miles per year, and that a vehicle will travel 60 miles/kg of hydrogen.
Technology Description
Hydrogen is produced via electrolysis by passing electricity through two electrodes in water. The water molecule is split and produces oxygen at the anode and hydrogen at the cathode.
Three types of industrial electrolysis units are being produced today. Two involve an aqueous solution of potassium hydroxide (KOH), which is used because of its high conductivity, and are referred to as alkaline electrolyzers. These units can be either unipolar or bipolar. The unipolar electrolyzer resembles a tank and has electrodes connected in parallel. A membrane is placed between the cathode and anode, which separate the hydrogen and oxygen as the gasses are produced, but allows the transfer of ions. The bipolar design resembles a filter press. Electrolysis cells are connected in series, and hydrogen is produced on one side of the cell, oxygen on the other. Again, a membrane separates the electrodes.
[attachment=20441]
Introduction
The purpose of this report is to give an overview of the current state of electrolytic hydrogen production technologies, and to provide an economic analysis of the processes. The study focuses on five companies’ current electrolyzer lines: Stuart IMET; Teledyne HM and EC; Proton HOGEN; Norsk Hydro HPE and Atmospheric; and Avalence Hydrofiller. The report details the state of technology as of December 2003 for all five companies’ electrolysis units, and then analyzes the economics of three standard sized electrolysis processes.
Analysis Methodology
The technical details for each company’s electrolysis systems were obtained from research on the Internet, and from personal conversations with industry representatives. The data presented are representative of systems available in December 2003. A detailed summary of each electrolysis model included in this study can be found in Appendix A.
For purposes of the analysis, the available electrolysis systems were categorized into five different size ranges: home, small neighborhood, neighborhood, small forecourt and forecourt. The term forecourt refers to a refueling station. The number of cars served and hydrogen production rate for each size are as follows:
• The home size will serve the fuel needs of 1- 5 cars with a hydrogen production rate of 200-1000 kg H2/year.
• The small neighborhood size will serve the fuel needs of 5-50 cars with a hydrogen production rate of 1000-10,000 kg H2/year.
• The neighborhood size will serve the fuel needs of 50-150 cars with a hydrogen production rate of 10,000 – 30,000 kg H2/year.
• The small forecourt size, which could be a single hydrogen pump at an existing station, will serve 150 – 500 cars with a hydrogen production rate of 30,000 – 100,000 kg H2/year.
• A full hydrogen forecourt will serve more then 500 cars per year with a hydrogen production rate of greater then 100,000 kg H2/year.
The number of cars served was determined by calculating that a car requires approximately 200 kg of hydrogen per year. This 200 kg requirement assumes that on average a car travels 12,000 miles per year, and that a vehicle will travel 60 miles/kg of hydrogen.
Technology Description
Hydrogen is produced via electrolysis by passing electricity through two electrodes in water. The water molecule is split and produces oxygen at the anode and hydrogen at the cathode.
Three types of industrial electrolysis units are being produced today. Two involve an aqueous solution of potassium hydroxide (KOH), which is used because of its high conductivity, and are referred to as alkaline electrolyzers. These units can be either unipolar or bipolar. The unipolar electrolyzer resembles a tank and has electrodes connected in parallel. A membrane is placed between the cathode and anode, which separate the hydrogen and oxygen as the gasses are produced, but allows the transfer of ions. The bipolar design resembles a filter press. Electrolysis cells are connected in series, and hydrogen is produced on one side of the cell, oxygen on the other. Again, a membrane separates the electrodes.