ADVANCES IN ONSITE HYDROGEN GENERATION FOR UPPER AIR

ADVANCES IN ONSITE HYDROGEN GENERATION FOR UPPER AIR OBSERVATIONS WMO TECHNICAL CONFERENCE ON METEOROLOGICAL AND ENVIRONMENTAL INSTRUMENTS AND METHODS OF OBSERVATION Helsinki, Finland, 30 August – 1 September 2010 Prepared and Presented by Proton Energy Systems

Upper Air Observations • Radiosondes are sensor packages attached to weather balloons that are filled with helium or hydrogen gas • The radiosonde generally consists of a radio transmitter, GPS receiver, temperature sensor (thermistor), humidity sensor, and sometimes a pressure sensor • A complete vertical profile of temperature, humidity, wind speed and wind direction in the vicinity of the launch station can be obtained during its two hour sounding to nearly 100, 000 feet up into the atmosphere

Lift Gas Use and Methods • Helium – – Delivery of pressurized cylinders is only option Scarce outside of U. S. A. Expensive (and getting more expensive) Pressurized cylinders pose logistical and safety concerns • Hydrogen – Delivery of pressurized cylinders • Expensive, poses logistical difficulties and safety concerns – On-site production through chemical reaction • Dangerous to personnel and the environment • Logistical difficulties and limitations on amount of gas produced – On-site production through electrolysis • Liquid electrolyte – Hazardous materials used, high maintenance, large footprint – Dangerous to personnel and the environment • Solid polymer electrolyte – No hazardous materials used, safe for personnel and the environment, easy to install and maintain, small footprint

On-site Hydrogen Generation Electrolysis of Water Utilizing KOH, circa 1800: Effect first discovered by William Nicholson, English chemist 2 H 2 O(l) → 2 H 2(g) + O 2(g) William Nicholson, ca. 1812 Oxygen gas (O 2) forms at anode Hydrogen gas (H 2) forms at cathode Engraving by T. Blood after a portrait painted by Samuel Drummond (1765 -1844)

On-site Hydrogen Generation So What is KOH Electrolysis? • Electrochemical Process that uses a liquid electrolyte of KOH (potassium hydroxide) • Hazardous Chemicals are used • Produces Hydrogen and Oxygen from Electricity and Water • Must maintain a balanced pressure between hydrogen and oxygen • Limited start and stop times

On-site Hydrogen Generation Electrolysis of Water Utilizing PEM: Initial PEM innovators Grubb & Neidrach, GE Research, 1955

On-site Hydrogen Generation So What is PEM Electrolysis? • Electrochemical Process that uses a solid electrolyte • Zero Hazardous Chemicals or Emissions • Produces Hydrogen and Oxygen from Electricity and Water • High Pressure without mechanical compressors • Very fast start and response times

On-site Hydrogen Generation PEM § No hazardous materials or chemicals required versus § – Contains high purity water only – Long component life – Safe for operators and service technicians – Easy to maintain and service, no caustic solution to drain and refill § Hazardous Caustic chemicals required – Corrosive to components – Possible asbestos content- known carcinogen and banned in many countries – Eye and skin hazard. Extreme caution required in handling – Special purification equipment required – Overboard discharges possible with expensive damage to downstream components Low Maintenance – Typical maintenance less than 4 hours per year – Any repair can be completed in 1 hour or less KOH § High Maintenance – Some require 40+ hours of maintenance per year and increases as corrosion damages components – Process component repair may require draining of caustic and extensive downtime

PEM vs KOH Installation Typical Bi-Polar KOH Hydrogen Plant Layout and Equipment Hydrogen Generator Inflating Bed Electrolyzer Tank

PEM vs KOH Installation Typical Bi-Polar PEM Hydrogen Plant Layout and Equipment Hydrogen Generator Inflating Bed Tank Electrolyzer, water system and tank

On-site PEM Hydrogen Generation • Summary of demonstrated PEM improvements to upper air operations – Safer • No hazardous chemicals required (safer for both personnel and the environment) • High differential hydrogen pressure (safety concernsexplosion and fire- of hydrogen/oxygen mixing are removed) • Mechanical compressor is eliminated – Smaller physical footprint – Fully integrated design • Rectifier, purification and electrolyzer in one cabinet – Easier to maintain – Higher reliability

Upper Air Observatory PEM Electrolyzer Installations