dry anaerobic digestion of municipal solid waste and digestate ...

Methodology Methodology for for Energy Energy Balance Balance Calculation Calculation of of Inclined Inclined Reactor
The The energy energy balance balance of of inclined inclined reactor reactor is is based based on on its energy consumption and energy
production. production. Energy Energy is is required required for for shredding shredding the the waste waste (ES), waste feeding and withdrawal
(EFW), (EFW), re-circulation re-circulation of of reactor reactor content content (ER) (ER) and and heating heating (EH) which includes energy for
heating heating the the substrate substrate (EHS) (EHS) as as well well as as energy energy for for maintaining constant thermophilic
temperature temperature (EMT). (EMT). The The production production of of energy energy (EP) (EP) is only from the methane produced.
Method Method for for calculation calculation of of each each type type of of these these energies energies has been given in the following
section.
section.
The The net net energy energy production production NEP NEP (MJ) (MJ) is is the the difference difference between the energy produced and
consumed consumed by by the the process process that that is is shown shown in in Figure Figure 1 1 and and given by the following equation:
Feeding
Feeding
Withdrawal
Withdrawal
Recirculation
Recirculation
Shredding
Shredding
Heating
Heating
NEP NEP = = EP EP - - ES ES – – EFW EFW – – ER – EH
Figure Figure E-1 E-1 Energy Energy inputs inputs and and output output of of inclined anaerobic digester
1.1 1.1 Energy Energy Production
Production
The The energy energy production production EP EP (MJ) (MJ) equivalent equivalent to to methane methane and hydrogen content of the
produced produced biogas biogas can can be be calculated calculated by by the the equation equation below.
below.
EP EP = = (MP (MP X X L.H.V. L.H.V. of of CH4) CH4) + + (HP (HP X L.H.V. of H2)
where
where
MP MP = = methane methane production production (L (L CH4)
CH4)
L.H.V. L.H.V. of of CH4= CH4= 0.03618 0.03618 MJ/L MJ/L CH4 CH4 CH4 (Ruggeri (Ruggeri et et al., al., 2010)
2010)
HP HP = = Hydrogen Hydrogen production production (L (L H2)
H2)
L.H.V. L.H.V. of of H2 H2 H2 = = 0.0108 0.0108 MJ/L MJ/L H2 H2 H2 (Ruggeri (Ruggeri et et al., al., 2010)
2010)
1.2 1.2 Energy Energy Consumption
Consumption
Energy Energy consumption consumption has has been been described described under under sub-categories sub-categories as follows:
1.2.1 1.2.1 Energy Energy required required for for shredding shredding (ES)
(ES)
The The assumption assumption here here is is that that about about 100 100 kg kg of of waste waste is is shredded by the use of 0.5 L gasoline.
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