Bioenergy is energy that is generated from living, or once living, organisms. Oil, coal, and natural gas are by definition forms of bioenergy, however are not sustainable because these fossil fuels are formed over the course of millions of years. Instead, this section will focus on bioenergy generated from faster-replenishing sources, which demonstrates how this resource can also function as a sustainable energy. Human ancestors had been using bioenergy in the form of wood fires hundreds of thousands of years ago, a technology that is still used today in modern wood stoves. Through a number of chemical and biological processes, the carbon within organic matter can be turned into carbon neutral fuel sources, called biofuels. New Brunswick has a wealth of resources that can be used to generate heat and electricity, and bioenergy projects can be seen all across the province!
Biomass refers to solid biological materials that can be used for energy generation or in place of fossil fuels. The energy stored in biomass can be released via combustion or gasification. Perhaps the most familiar example is burning wood products such as logs, pellets, and densified hardwood shavings. Other common forms of biomass include agriculture residues (straws, stalks, leaves), urban wastes (municipal food waste, lawn waste, wastewater sludge), and animal byproducts (manure, fats) that can be used for land application purposes. Biosolids are fantastic sources of soil nutrients and can be used as fertilizers.
While land application isn’t traditionally a form of renewable energy, it can have a variety of beneficial environmental impacts on the soil and water quality of local ecosystems. Various biomasses can be used to strengthen soil profiles, prevent erosion, and provide nutrients to local waterways to promote ecosystem development. While the specifics of land applications are outside the scope of this website, we believe that this biomass use is worth mentioning.
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A number of processes exist to further refine biomass products into usable fuels. Anaerobic digestion is the process of allowing microorganisms to break down biomass products in the absence of oxygen. As the biomass products break down, they produce liquors and biogases that have a much higher energy potential than their solid counterparts. These high-energy products are referred to as biofuels and may be used in place of, or mixed with, fossil fuels. Ethanol is an example of a biofuel that is commonly mixed with gasoline.
By definition, combustion of any organic material will result in carbon dioxide emissions. Biofuels however are referred to as carbon-neutral energy sources. Plants use photosynthesis to grow, and this reaction consumes carbon dioxide and produces oxygen gas. The carbon is stored within the plants, and can be released at the end of the plant’s lifecycle when it is burned, or otherwise used, for energy. Since the carbon dioxide released by the plants had previously existed in the atmosphere, no new carbon dioxide is being emitted. This is contrasted by fossil fuels where they are stored in solid or liquid form within the earth, and release new carbon dioxide into the atmosphere when burnt.