Tag: chemistry

Sewer gas is a complex mixture of toxic and nontoxic gases produced and collected in sewage systems by the decomposition of organic household or industrial wastes, typical components of sewage. Sewer gases may include hydrogen sulfide, ammonia, methane, esters, carbon monoxide, sulfur dioxide and nitrogen oxides.

The following are the advantages of using hydrogen as an automobile fuel.
The amount of energy released per unit weight of the fuel is very high.
The combustion hydrogen does not produce polluting emissions of CO, $CO _2$, oxides of nitrogen, and sulphur, aldehydes etc. Here, combustion product of hydrogen is water with few traces of nitrogen oxides. So no pollution is caused.
The technology required for use of hydrogen fuel is simple and cost effective.
The fuel cells using catalytic combustion of hydrogen have efficiency of 70-80 percent.

Molasses is a factory waste from sugar industry. It does not contain any traces of methane. So, methane is not obtained from molasses.

Hydrogen gas is considered as the cleanest fuel because when hydrogen burns in air, it produces nothing but water vapour.

Wars between countries can also hamper supply of energy specially if it happens in Middle East countries like Saudi Arabia, Iraq, Iran, Kuwait, UAE or Qatar. Thats what happened during 1990 Gulf war when price of oil reached its peak causing global shortages and created major problem for energy consumers.

Higher the methane content, higher the calorific value. Pure $CH _4$ has a Gross Calorific Value of 39.8 $MJ/m^3$. the rate of combustion of biogas is quite high as it is produced by anaerobic decomposition of animal and plant waste.
It does not leave any ash behind after burning as cow dung and other organic matter is used in the preparation of biogas.

When dead plants get buried into the bottom of the soil they are slowly converted into coal due to high pressure and high temperature. Heat and pressure produced chemical and physical changes in the plant layers which forced out oxygen and left rich carbon deposits. In time, material that had been plants became coal.

Coal is neither malleable nor ductile. It is brittle. It would crumble if it is  tried to draw it into a wire.

Since coal is a form of sedimentary rock, it's is hard and porous. It is black due to its prime composition of carbon, compressed at high temperature and pressure.