Hydrogen from Sunlight

Introduction

By exposing a solution of hydrogen sulfide to electromagnetic radiation from sunlight, an efficient and inexpensive way has been discovered to create hydrogen, which can be used in fuel cells to produce clean energy. The discovery made by Tohji at Tohoku university can reduce the cost of producing hydrogen, which can be converted to energy without any pollution, the fuel cells. Hydrogen is produced when water is decomposed by passing electricity through it but it can also be created through photodecomposition when hydrogen sulfide is exposed to sunlight. Several other attempts of using sunlight to create hydrogen had failed to succeed.

Extraction of hydrogen from hydrogen sulfide requires half of the energy required for extracting hydrogen from water. To make use of this advantage, Tohji attempted to decompose H2S by creating a new catalyzer from extremely tiny particles of sulfated cadmium. By molding the catalyzer into the shape of an eggshell, he put it into a water solution of H2S, and then whipped it into a froth to create hydrogen. About seven litres of hydrogen can be produced per hour from a solution spread out over a surface area of one square meter. This amount is 20 times greater than that extracted by the conventional process. The electricity required for one household could be produced from a pool of the solution with a surface area of 200 m2. Efforts are being made to take acre of the sulphur coming out of the decomposition process and once it is achieved, another source of energy, which is less expensive and also less pollutant than petroleum would have been established.

Main Application: Energy

Contact for more information:

Science & Technology Wing Embassy of India
2-2-11, Kudan Minami, Chiyoda-ku
Tokyo 102-0074, Japan
Tel: +81-3-3262-2391 to 97,
Fax: +81-3-3234-4866
E-mail: tandonus@hotmail.com