ABSTRACT
The continual increase in the price of non-renewables and associated GHG emissions, makes LFG utilization technologies for energy production an important alternative energy source for economically developing countries. It is therefore fundamental to develop and implement LFG utilization technologies that involve low investment, operational and maintenance costs, are relatively labour intensive with low energy consumption in order to yield a highly positive energy balance. The list of innovative uses for LFG continues to grow; currently there are at least 30 different applications for LFG:
1 Gas engine 2 Vehicle fuel 3 Compressed natural gas 4 Gas turbine 5 Boiler 6 Infrared tube heater 7 Microturbine 8 Steam turbine 9 Thermal oxidizer 10 Cogeneration 11 Brick kiln 12 Paint shop oven burner 13 Combined cycle 14 Incinerator fuel 15 Paint evaporator 16 Leachate evaporator 17 Asphalt heater 18 Blacksmith forge 19 Condensate evaporator 20 Lime kiln 21 Greenhouse heat 22 Sludge dryer 23 Clay dryer 24 Glass kiln
25 Cement kiln 26 Ceramic kiln 27 Fuel cell 28 Metal furnace 29 Pipeline gas 30 Liquefi ed natural gas
6.2 LFG TO ENERGY TECHNOLOGIES
The utilization of LFG for power generation, or processing to natural gas, or fuel for boilers and furnaces are considered as a renewable energy sources which can compensate for the shortage of fossil-fuel-based energy generation. However, the feasibility of LFG utilization technologies depends on the economic viability, site conditions and end-use markets. Power generation from LFG and processing of LFG to pipeline-quality natural gas as fuel for vehicles has become more common in recent years. The benefi cial use of LFG is highly dependent on the quantity, quality and effi ciency of the LFG collection system. The key LFG to energy utilization technologies discussed in detail in this chapter are:
1 Microturbines 2 Reciprocating Internal-combustion engines (ICEs) 3 Stirling Cycle Engines 4 Steam turbines 5 Direct use of LFG 6 Alternative Fuel (CNG/LNG) 7 Power generation using LFG-driven engines 8 Boilers 9 Fuel Cells
The LFG collection system should be designed and operated for consistent and steady supply of LFG to the utilization system. The key factors that should be considered while selecting an LFG utilization technology includes:
1 The expected landfi ll closure year, 2 The economics of the LFG project i.e., the capital and Operation & Maintenance
costs and revenue from energy sales, 3 Size requirements for the LFG utilization equipments for the project.
