Essentially biomass energy comes from the sun since plants use its energy to undergo the process of photosynthesis which takes place during their growth and results into storing energy into their roots and leaves. In addition animals which can also be used as biomass fuel might eat plants to help them grow.
Biomass is considered a renewable energy source and is produced with the usage of organic materials such as plants and animals as already mentioned. The main biomass fuel that is known to all of us is wood and its byproducts. The main methods to produce biomass energy are from thermal treatment (i.e. incineration, gasification and pyrolysis) , biochemical processing (i.e. anaerobic digestion) and chemical treatment (i.e. biodiesel).
Wood burning to produce heat or for cooking meals was used by our ancestors and still takes place today at our homes nowadays making biomass energy probably the oldest form of energy that humans use. The use of animal as fuel source to produce biomass energy is less known to us, an example of it is the usage of animal manure to produce syngas.
The biggest advantage of biomass energy is the fact that is a sustainable form of energy because its source fuel can be replaced. For example, if we burn a tree for its wood we can replace it by replanting a new one. As a result biomass doesn’t increase the carbon dioxide emission levels of the environment since the quantity emitted during combustion can be recaptured by replanting. The replanting should be careful planed though to avoid burdening the environment further. For instance, Biomass energy that comes as a result of deforestation is considered harmful for the environment since it is not sustainable and the Co2 emissions from producing it will be added to its balance. In the case of fossil fuel even though the fuel might be of organic origin the Co2 emissions produced have been removed from the environment’s balance thousands of years ago thus releasing it into the environment now does have a negative impact.
In the case of crops that are used as biofuel, (i.e. corn to produce ethanol ), there is always the counterargument that even though the Co2 emissions will be recapture from replanting it takes energy to be produced that comes from machines using some sort of fossil fuel. There are recent studies that actually measure the extend of net benefit of energy from cultivating such crops with some of them estimating the additional energy coming out of corn ethanol to 25% and soy beans for the production of biodiesel being almost an additional 100%. Moreover there are concerns that the recent increase in the price of corn is a result of its use as fuel and there is always the argument that it can increase the need for farming land that might threat forests.
At our homes we still use biomass for heating purposes. In the past years and even today fireplaces have been extremely popular. Today there are also modern biomass stoves that use other fuels with the most popular ones being wood pellets or corn. According to The US energy information administration heating cost per million BTUs ranks biomass fuels (wood, wood pellets and corn) as the cheapest behind coal. If we take in consideration the fact that coal Co2 emissions will never be recaptured then the financials benefit from using it can be outweighed.
Finally another form of biomass is from the waste to energy process. The most common method to produce heat and/or electricity for this process is through incineration of gasification of waste coming from households, schools, offices which are called municipal solid waste (MSW). One of the concerns that waste to energy incineration raises is the fact that it might reduce the incentive for recycling. The biggest concern though, has to do with the fact that In the case of incineration not all MSW used are of organic origin thus raises environmental concerns and cause damage the environment even though with modern filtering, proper levels of incineration heat and thorough pre-sorting at plants sites we can eliminate such risk. In addition since a portion the MSW used in WTE incineration is non-organic some argue that it is not biomass or at least pure biomass and it is not a renewable form of energy. On the other hand, proponents argue that humans will always produce non-organic waste thus it is sustainable and that WTE incineration benefits the environment since Landfilling of waste produces methane which contributes by approximately 25 more times to the GHG.
Biomass energy is renewable and sustainable if used properly. With the prices of fossil fuels being on a constant high the past few years increasing the usage of biomass energy can help us reduce our dependency on them.