Final answer:
Biodiesel is made from vegetable oil or used vegetable oil and produces fewer harmful emissions than petrodiesel but more nitrogen oxide. Bioethanol, made from crops like corn and sugarcane, burns cleaner but results in higher evaporative emissions. Both biofuels affect food prices and land use, and their energy efficiency is measured by EROEI.
Step-by-step explanation:
Biodiesel vs. Petrodiesel Bonds
Biodiesel and bioethanol are both liquid biofuels that serve as alternatives to their petroleum-based counterparts. Biodiesel is typically made from vegetable oils derived from crops such as soybean, sunflower, and rapeseed, and can also be produced from used vegetable oil. Unlike petrodiesel, the combustion of biodiesel produces lower amounts of sulfur oxides, particulate matter, carbon monoxide, and hydrocarbons, but higher levels of nitrogen oxide. Bioethanol is created by fermenting crops like corn and sugarcane and then mixing them with traditional gasoline. This mixture burns cleaner than pure gasoline but has higher evaporative emissions contributing to smog and ground-level ozone formation. The economic and environmental impacts of biofuel production are significant; there can be competition for land between fuel and food production, potentially leading to increased food prices and land use issues such as deforestation.
The subject also touches upon the concept of Energy Return on Energy Investment (EROEI), which measures the efficiency of a fuel based on the energy output relative to the energy input required for its production. Biofuels are especially important as liquid fuels due to their high energy density and versatility, being one of the few renewable resources suitable for transportation applications, particularly in vehicles. It is important to consider these factors alongside sustainability when discussing the viability of biofuels as long-term energy solutions.