Research on the Landfill Gas Utilization Possibility on Municipality Solid Waste Landfill Suhodol for Electricity and Heat Energy Recovery
Background:
The municipality landfill Suhodol is located 1.2 km far from the Suhodol district
of Sofia. The landfill is divided into two parts: the first has been in operation
since 1994 to 1997 and some 500 000 t waste have been dumped there. The First
part is closed and capped with an impermeable construction. The waste stored
in the place is in real methane degradation phase and produces landfill gas
with about 50% methane content. The second part is under operation since 1997.
Motivation:
A pilot plant can be constructed for utilization of the gas from the first part,
and in addition extended in the future to cope with the gas from the Second
part of the landfill. It is regarded as a project with high priority for the
City of Sofia. Such experience could be transferred to the other sites in Bulgaria
as well.
The project has environmental and social benefits. The methane as a main component
of the landfill gas is a potent greenhouse gas with 21 times stronger impact
to the global warming than CO2. Landfill gas capturing and incineration will
reduce: the methane emissions, the odor effect, and the risk of explosion. The
installation will create new job opportunities on local level.
Results:
Worldwide practice shows that the landfill gas produced as a result of the unsorted
waste degradation may be profitably utilized. The experience in this area exists
and a lot of proven solutions ware investigated and their pros and cons ware
discussed in the work. The most appropriate technology that is widely accepted
and suitable in our case is the spark ignition gas engines. The waste heat from
the engines can be used for district or greenhouse heating to increase the energy
efficiency of the installation (cogeneration).
According to recent assessment made by Sofia Energy Agency some 280 m3/h landfill
gas now evolved to the atmosphere can be recovered and utilized in a gas engine
with 500 kW electrical and 800 kW heat capacity. The period of exploitation
of the power station will be extended after starting to use the Second part
of the landfill in 2006. Then the electrical capacity will be increased to 2,5
MW and emissions of 5 000 tons/yr CH4 (110 000 tons CO2 equivalent) will be
avoided.
Some preliminary calculations ware made in order to define the investment (EUR
3 million) and O&M costs (EUR 200 000 annually) needed. The simple payback
period was estimated to be 5 years.
As a part of the investigation, some preliminary contacts with potential investors
from Netherlands and Denmark were established. Possibilities to use mechanism
like Joint Implementation (Kyoto Protocol) or the scheme Built-Operate-Transfer
(BOT) were discussed on municipal level.
Public
Presentations:
The project report was presented on the Energy Forum 2003, 12-15 June 2003,
Varna, Proceedings, Volume 1.
An article was published in the magazine Installations, Issue 2, 2003.
Authors:
Assoc. Prof. Ivan Shishkov, Assoc. Prof. Simeon Simeonov, Dipl. Eng. Zdravko
Georgiev
For
contacts:
Assoc. Prof. Ivan Shishkov
Executive Director