Is Biomass Green ?

‘’Is biomass a green energy source?’’; as a green energy systems manufacturer we often get that question.

First and foremost combusting biomass in order to produce energy does emit as much CO2 as burning fossil fuels.  ‘’Then why is biomass considered Carbon neutral?’’ you might ask?  Unlike Fossil fuels, biomass has a very short life cycle.   For example when a mature forest is harvested, it will soon regenerate itself and replace the old one.  The young trees are the ones that do the most to sequester CO2 out of the atmosphere and transform it into Oxygen.  A mature forest does not capture much CO2 because it is at the end of its life cycle and is no longer actively capturing carbon.  So done under a sustainable management program, harvesting mature forests can be beneficial for the environment.

Fossil fuels on the other hand have been stored under the earths crust for millions and millions of years.  Human beings are currently tapping into this stored energy source at a rate that far exceeds the planets natural carbon capture cycle.  That is the reason for the carbon built up that we are experiencing.  In comparison, the forest has a very short life cycle, 30 to 100 years depending on the species.  Using biomass as an energy source does not emit more CO2 than what can be recycled naturally; this is why biomass is considered Carbon Neutral.

Most of the forestry operations today are taking the branches and tree tops that don’t make the grade for the pulp and paper or sawmilling industry and use it to produce energy in the form of heat and or electricity.  If this wood was left behind it would de decompose naturally and produces methane.  Methane can be 20 times more damaging to the ozone layer than CO2.

With the new combustion and filtration technologies that exist today; using biomass can be very clean.  Biomass does not have the high sulphur content that coal and oil has.  It also does not generate as much NOx as Oil since it burns at much lower temperatures.  Coupled with the appropriate pollution control devices, biomass can emit less particulate than natural gas.  When you see a great white plume coming out of a biomass fired energy system on a cold day, it’s not smoke, it’s water vapour condensing which is a bi-product of the combustion process.

Other advances in technology in recent years have also cleaned up the biomass combustion systems; things such as opacity monitoring and O2 trimming.  O2 trimming will use an oxygen sensor that will control the amount of biomass that is being fired into the combustion chamber in order to maintain the optimum fuel to oxygen ratio necessary for clean combustion.

Another positive thing that can be said about biomass systems is that the fuel that it will use will be harvested by local people and local entrepreneurs.  This will stimulate the local economy and create local jobs instead of encouraging the oil and gas industry, which have their raw materials primarily sourced in foreign countries. 

Simply put ‘’Is biomass a green energy source?’’………………Yes!