Friday, 28 November 2014


It has not been very long that Indian Railways has introduced bio-toilets in the trains and the process of instalation is still ongoing. At the present structure, the working of bio-toilets in trains mainly involves the following steps namely:

1.            Collection of human waste;
2.            Anaerobic digestion of the human waste;
3.            Release of the methane and Co2 into the atmosphere;
4.            Production of liquid waste/effluent; and
5.            Discharge of the effluent into the track after chlorination.

The main focus of this write-up is point number 3 i.e. release of the methane into atmosphere. With the help of emerging technologies, instead of letting the gas escape into atmosphere if we can capture such gas and purify it, it can have multiple economic and environmental benefits. The following model can be helpful in this regard:


BT = Bio-Toilet/BGC = Bio Gas Collector/BGP = Bio-Gas Pipeline/AD (BW) = Anaerobic Digester for other bio-wastes/RGBP = Raw Bio-Gas Purifier/RBGC= Raw Bio-Gas Collector/PBGT= Purified Bio-Gas Tank


·Bio-gas generated from the coach bio-toilets i.e. BT-1 and BT-2  will be collected to a separate container attached to the coach i.e. BGC;

·In major stations with evacuation facility, the bio-gas present in BGC will be evacuated through dedicated pipeline i.e. BGP;

·BGP will transfer and deposit the bio-gas into a raw bio-gas collector i.e. RBGC;

·Bio-gas present in RBGC will be purified through purifying mechanism i.e RBGP-1 and the purified bio-gas will be transferred to a purified bio-gas tank i.e. PBGT;

·On the other hand, other bio-wastes (say food leftover etc.) will be collected from the coach when the train is stationary and deposited into an anaerobic digester for bio-degradable waste i.e. AD (BW);

· AD (BW) will produce bio-gas and such gas will pass through purifier RBGP-2 and ultimately deposit into PBGT; and

·Now Indian Railways or any other private operator can bottle the bio-gas from PBGT and utilize them commercially for revenue generation.

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