A firelog is a manufactured log constructed to be used as wood fuel. Firelogs are designed to be inexpensive, while being easier to ignite, and burn longer, and more efficiently than firewood. Firelogs are traditionally manufactured using two methods. The first uses only compressed sawdust and the second uses sawdust and paraffin, which is mixed and extruded into a log shape. The extruded firelogs are individually wrapped in paper packaging which can be ignited to start burning the firelog as the paraffin is readily combustible.
A new cleaner firelog has now been developed using waste fibre from the oil palm fruit bunches of South East Asia. Unlike sawdust logs these burn with zero sulfur emissions. Also unlike sawdust logs no trees need to be felled to produce these firelogs, meaning more oxygen and less carbon dioxide in the atmosphere. The same is applicable for another new type of firelogs made from renewable Greek cotton plants, offering a high energy contents.
Another new type of firelog is made from waste wax-cardboard such as that used in the packing of perishable foods for shipment, which is used to create a compressed cardboard firelog.
The materials used for a traditional firelog are variable, the sawdust used is often commercial wood waste from manufacturers, or waste agricultural biomass (nut shells, fruit pits, etc.); additionally bio-wax may be used in lieu of paraffin (petroleum-based wax).
There are now a number of wood and wax firelogs made with using renewable materials. These are made using plant or animal based renewable waxes such as palm oil. These logs can be considered to be carbon neutral firelogs during combustion as the carbon released on combustion is the same carbon absorbed when the plants are growing. Sulphur emissions are virtually eliminated with renewable firelogs as they do not contain paraffin waxes.
|Firewood||6400 BTU/lb||14.9 MJ/kg|
|Extruded firelog||1500 BTU/lb||3.4 MJ/kg|
|Compressed firelog||8500 BTU/lb||19.8 MJ/kg|
|Palm fibre firelog||10500 BTU/lb||24.4 MJ/kg|
|Cotton plant firelog||17000 BTU/lb||39.8 MJ/kg|