(best examples and good practices) on household organic waste ...

219
Figure 57.: ARTI Compact biogas plant scheme (gasholder empty <strong>and</strong> gas -
filled )
The effective volume of the digester is approximately 850l, given by the
dimension of the 1000l-water tank (inner radius: 51.5cm) <strong>and</strong> the position of the
overflow-pipe (1.04 m above ground level ) . The total surface area of the
digester (0.83m 2 ) is covered by roughly 0.65m 2 (78%), in other words the gas
released through 22% of the digester surface is lost to the atmosphere without
utilization. The usable gas volume of the 750 l - gasholder is 400l. The
Hydraulic Retention Time (HRT) suggested by ARTI-TZ, which describes the
ratio of the reactor volume (0.85m 3 ) to the f low rate of t he influent substrate
(0.02m 3 /day) , is 42.5 days. The seeming lyrather long period of time that
digester liquid spends in the reactor is justified by the appearances of sinking
<strong>and</strong> floating layers. (Riuji., 2009)