Engineering Chemistry S Datta

FUELS AND COMBUSTION 403
Conditions for Biomethanation
• Temperature = 35°
• pH = 6.8-8.2
• Anaerobic condition.
• Trace elements = Na + , Co +3 , Ni +2 etc.
Arrangements for Biomethanation
Feed stock is mainly cowdung.
Gas
Gas
Excess feed stock
(Batch process)
Feed stock
(a)
(b) Feed stock
Fig. 18.15
Better quality of coal should have low nitrogen and sulphur content. Higher percentage
of oxygen is also undesirable as an increase in 1% oxygen content decreases the calorific value
by about 1.7%.
Method of Analysis of Flue Gas
Analysis of flue gas will indicate the complete or incomplete combustion of a fuel; which
is very essential in respect of efficient utilization of the fuel. The analysis is done in Orsat’s
apparatus and is based on the principle of absorption of
• CO 2
in KOH solution (500 gl –1 , 500 ml)
• O 2
in alkaline pyrogallic acid (25 g of pyrogallic acid in 400 gl –1 KOH solution, 500 ml)
• CO in ammoniacal cuprous chloride solution (100 g Cu 2
Cl 2
+ 125 ml liquor ammonia
+ Rest water to make up the volume, 500 ml).
Description of the Apparatus
It consists of a water jacketted measuring burette, connected in series with the absorption
bulbs containing the above three solutions successively as depicted in the Fig. 18.16. The water
jacket maintains the temperature of the gas constant. The absorption bulbs are filled with
glass tubes for better absorption of the gases.