question_answer

Draw the labelled diagram of dome type bio-gas plant and explain its construction and working. Or Energy from various sources is considered to have been derived from the sun. Do you agree? Justify your answer.

Answer:

The diagram of dome type bio-gas plant is shown as Construction The bio-gas plant is a. brick and cement structure having the following five sections Mixing tank It is present above the ground level. ·         Inlet chamber The mixing tank opens underground into a slopping inlet chamber. Digester The inlet chamber opens from below into the digester which is a huge tank with a dome like ceiling. The ceiling of the digester has an outlet with a valve for the supply of bio-gas. Outlet chamber The digester opens from below into an outlet chamber. Overflow tank The outlet chamber opens from the top into a small over flow tank.                                          (1) Working The various forms of bio-mass are mixed with an equal quantity of water in the mixing tank. This forms the slurry. The slurry is fed into the digester through the inlet chamber. When the digester is partially filled with the slurry, the introduction of slurry is stopped and the plant is left unused for about two months. During these two months, an anaerobic bacterium present in the slurry decomposes or ferments the bio-mass in the presence of water. As a result of anaerobic fermentation, bio-gas is formed, which starts collecting in the dome of the digester. As more and more bio-gas starts collecting, the pressure exerted by the bio-gas forces the spent slurry into the outlet chamber. From the outlet chamber, the spent slurry overflows into the overflow tank. The spent slurry is manually removed from the overflow tank and used as manure for plants. The gas valve connected to a system of pipelines is opened when a supply of bio-gas is required. To obtain a continuous supply of bio-gas, a functioning plant can be fed continuously with the prepared slurry.                         (2) Or Yes, sun is the ultimate source of energy. Directly or indirectly, all the forms of energy are derived from solar energy. ·   Non-renewable Sources of Energy Fossil fuels like coal petroleum and natural gas are formed due to burial of large plants and ancient creatures whose ultimate source of energy is sun. ·   Renewable Sources of Energy They are indirectly derived from solar energy such as (i) Energy from Flowing Water Clouds are formed when water in lakes, rivers, seas, etc evaporates due ro solar energy. They bring rainfall and snowfall. The rain and melting snow feed rivers, streams, etc. This flowing water can be used for getting hydroelectricity. (ii) Wind Energy It arises due to uneven heating of the earth's surface by the sun rays at two different adjoining places. Due to this, wind possesses kinetic energy. (iii) Bio Energy Plants in the process of photosynthesis converts the solar energy into food (chemical energy). This food is consumed by animals. This, the animal wastes and remains of the plants constitute bio-mass which can be utilised as a source of energy. (iv) Wave Energy The waves are generated by strong winds (due to solar energy) blowing across the sea. (v) Ocean Thermal Energy Sun is responsible for the temperature difference between the water at the surface and water at depth in seas and oceans. ·   Solar heating devices derive their energy directly from solar energy and convert it into other usable forms of energy. Thus, the energy from various sources are considered to have been derived from the sun.