Identify examples of biofuels. Assess the feasibility and sustainability of using biofuels for power generation

Question

What will be an ideal response?

Answer 1

Biofuels include wood from trees, charcoal from burned wood, combustible animal waste (used directly for biopower), and products such as ethanol, methanol and biodiesel, which are derived from processing once-living matter. Captured landfill methane can be used as fuel as well, which consequently reduces methane gas emissions. Using biomass can be energy- and cost-efficient and is an inexpensive fuel for combustion in power plants. Although combustion of biomass releases carbon dioxide into the atmosphere, emissions are lower than through burning fossil fuels. There is no net addition of carbon to the atmosphere (carbon neutrality) because biomass is the product of recent photosynthesis—the carbon output of its combustion is balanced by the carbon input of the photosynthesis that created it. Where waste costs money to dispose of, using waste for fuel can save money. Liquid fuels made from biomass are competitive in price with petroleum gasoline. Gas–ethanol mixtures and biodiesel successfully fuel vehicles, stoves, and heaters, and these biofuels burn cleaner than conventional gasoline and petrodiesel. The technology used to process biomass is important, however, because processing biomass into biofuels can be energy-intensive. Growing crops exclusively for energy is not sustainable if monocultures are grown on land that could otherwise be preserved and if farmers apply petroleum products, such as pesticides, herbicides, and fertilizers, to their crops to increase yields. In addition, these agrochemicals cause damage to biodiversity, promote eutrophication, and contaminate water supplies. Overharvesting wood and crops is also unsustainable because it can lead to deforestation, soil erosion, and desertification, which damages landscapes, eliminates biodiversity, and impoverishes human societies dependent on an area's resources. Careful long-term planning and analysis is necessary to decide what level of crop-produced biofuels can be sustainable in a given area.