2nd UF Water Institute Symposium Abstract

Submitter's Name Noorie Rajvanshi
Session Name Poster Session: Managing Water and Energy in a Transitioning Environment 1
Category Managing water and energy in a transitioning environment
Poster Number 315
Author(s) Noorie Rajvanshi,  Mechanical Engineering
  Mark Brown,  Environmental Engineering Sciences
  Comparing Energy Cost of Water in the Production of Biofuels from Corn, Pine and Sweet Sorghum
  Liquid fuels derived from fossil fuels constitute one of the largest parts of energy consumption in the United States and worldwide. Biofuels like ethanol and biodiesel are seen as potential replacements for these liquid fuels derived from fossil fuels. The world ethanol production increased by more than 200% from 19 billion liters in 2001 to 66 billion liters in 2008 and is projected to increase further owing to political and trade decions. With the increasing scale of markets it has become important to understand and evaluate the environmental and energetic impacts of the production of ethanol. Water is one of the important resources affected by this increase in biofuel production. A unique way to quantify the water utilization in biofuel production is by calculating the water cost in terms of emergy. This can be achieved by calculating three different costs associated with water resources: Resource Costs (RC), Financial Costs (FC), and Environmental Costs (EC) and converting these costs in terms of emergy based monetary values. Financial Costs are the direct costs associated with supplying water, which include energy, materials, labor and infrastructure. Resource costs can be derived from two aspects of water, viz. chemical potential and geopotential. And finally the environmental cost also known as opportunity cost can be calculated using the GDP and total water consumption of the geographical area. This study is based on data from corn ethanol plant in South Dakota, a demonstration cellulosic conversion plant using woody biomass as feedstock in California and sweet sorghum ethanol plant in India. The study compares the emergy cost of water used for these three feedstocks. The financial value of the product, i.e. ethanol has also been compared with the financial and emergy cost of water for these three cases.