Life cycle and air pollution impacts assessment of transportation fuels from local alternative feedstocks including regional food, agricultural and green waste, and power plant carbon dioxide
The potential for local renewable electric power generation and energy reduction via efficiency, conservation and land use planning, notwithstanding, basic risk planning and portfolio diversification suggest that we plan for a future in which a significant proportion of Los Angeles's transportation energy needs are liquid fuel derived, for which biofuels are the cheapest alternative. The scarcity of urban cropland coupled with the Grand Challenge's goal of achieving 100% local water, could render crop-based biofuels -- including second–generation cellulosic-biofuels -- as unattractive. With concentrated source carbon dioxide (CO2) being an input to algae production, one has the potential to use emissions from L.A.'s numerous industrial facilities. This project addresses sustainability objectives as well as sociopolitical need for alternative fuels serve to forward the goals of clean air for both human and ecosystem health. To this end, the project proposes engineering-economic and environmental life cycle impact assessment of an integrated waste, CO2-based algal biofuel system. The metrics derived will include the levelized cost of energy (LCOE) produced, cost-per-tonne of GHG emissions avoided in addition to energy, water and cost reductions at industrial facilities.
Institute of the Environment and Sustainability, Physical Sciences
Atmospheric and Oceanic Sciences, Physical Sciences
Progress and Results
The study found that the U.S. has the potential to generate 3.1 to 3.8 exajoules (a measure of energy) of renewable energy each year using available waste resources. By comparison, the entire states of Washington and Oregon consumed about 3.3 exajoules of energy in 2017, according to the Energy Information Agency. The study also concluded that using waste products has the potential to displace 103 to 178 million metric tons of carbon dioxide emissions — an amount equivalent to taking 37 million passenger vehicles off the road based on typical passenger vehicle emissions of 4.6 metric tons of carbon dioxide each year.
A key finding was that no one method of bioenergy production maximizes net energy gain, renewable energy gain and climate benefits. Some create more renewable energy, but require more energy to do so, resulting in less overall greenhouse gas emissions savings. Thus, identifying the optimal bioenergy application in any situation depends on the intended outcome.