Efficient and economical Hydrogen production by using Mesh cathodes

Fossil fuels such as oil, coal and natural gas supply 85% of World’s energy consumption. Considering the oil market report from International Energy Agency, Global oil product demand increased by a robust 2.5% - 88.2% mb/d in 2008. The large demand has come closer than ever to exceeding world’s known production ability. if oil production remains constant until is vanished, it is anticipated that it will last for another 42 years. Similarly there is sufficient of natural gas to serve the demand for 61 years and coal for 133 years. Everyone realizes that fossil fuel will become scarce and costly in the nearly years.

In addition of petroleum crisis, increased use of fossil fuel resulted into higher release of carbon dioxide, a major component of green house gas. Increasing magnitudes of greenhouse gases in atmosphere are resulting into increase in global temperatures, with potentially harmful results for the environment and human health. Inevitably a conversion to sustainable energy sources is forthcoming. Alternative energy sources are renewable such as wind, solar, geothermal, hydroelectric and biomass. As compare to conventional energy sources, they have lower carbon emissions. Until now, only hydroelectricity and nuclear power have been major alternatives to fossil fuels.

Hydrogen is the most abundantly found element on the earth and is present in infinite magnitudes. Hydrogen gas has one of the highest energy density values. Presently many people claim a hydrogen economy that is based on using hydrogen as an energy carrier.  Hydrogen fuel cell combines hydrogen and oxygen chemically to develop electricity, water and waste heat and hence it doesn’t create pollution. Fuel cells are costlier to produce as compare to standard internal combustion engines however with new technologies and production systems, they are becoming more cost-effective.  

Hydrogen gas can be developed in various ways from hydrogen containing compounds like water, biomass and fossil fuel. Presently commercial bulk hydrogen is developed from natural gas through steam reforming. Renewable methods of sustainable hydrogen production include water electrolysis and biological processes for example biophotolysis, photo or dark fermentation. Only 4% hydrogen is produced from water splitting by electricity received from different sources at a standard energy efficiency about 56 to 73%. The efficiency of biophotolysis conducted by algae and photosynthetic bacteria is low and needs large surface area for the process. Hydrogen can be developed from different types of biomass such as carbohydrates for example glucose and polysaccharides.

Microbial electrolysis cells offer a suitable method to develop hydrogen from renewable biomass and wastewater. To create an economical and highly efficient mesh cathode, technology advancement is required. Considering the factor that stainless steel is more economical than platinum as catalyst, stainless steel mesh with larger surface areas than flat sheets are used as cathodes in the Microbial electrolysis cells. Analysis shows that mesh could have about three times active surface area than flat sheet. The relative position of mesh in correspondence of current density in MEC is in agreement with linear voltammetry studies at small bubble coverage. Mesh cathodes widely promise for the hydrogen development at low cost.