Organic Waste Recycling

188 Organic waste recycling: technology and management

Remedy a) Seed with slurry from a working digester before adding the new slurry to the digester; rotate the gas holder daily. b) In cold weather it takes about 3 weeks to fill the gas holder for the first time. c) No slurry should be fed in until sufficient amount of burnable gas has been produced. d) About 0.25 L of water should be poured into the dipper pipe and the excess removed. e) Should be located and repaired. a) Close the taps. b) Pour water into water outlet device to remove excess water. c) Leaks should be located and repaired

Cause a) Very few bacteria b) Lack of acclimation time. c) Feeding of slurry while waiting for gas holder to fill. d) No water in water outlet device. e) Leak in gas holder or gas pipe. a) Condensate or water outlet tap open (if fitted) or gas tap for burner open or gas cock for lamp open. b) No water in water outlet device or syphon. c) Major leak in the pipe-work.

Table 4.19 Problems with the operation of the biogas plant (adapted from Tata Energy Research Institute 1982) Problem 1. Gas holder (of floating type) does not rise or bag (of flexible bag type) does not inflate or pressure (of fixed dome type) does not rise at the start of the operation. 2. Gas holder or bag (or pressure in fixed dome type plant) goes down very quickly once main gas valve is opened.