America Runs on Biodiesel

Global warming and sustainability have been increasingly relevant issues. Greenhouse gases (GHG) such as carbon dioxide and methane are known to absorb heat and emit it into the atmosphere. The maturation of biofuel process technology aids in the transition from depletable fossil fuels that contribute in larger quantities to these emissions. Biodiesel and petroleum diesel blends such as B5 and B20 are becoming increasingly common. Biodiesel is also nontoxic, biodegradable, and safer to transport than petroleum diesel. Unlike the majority of biodiesel processes, which use a virgin oil as the main feedstock, our process uses a feedstock that is considered waste. Our goal is to reduce greenhouse gas emissions by producing biodiesel from wet spent coffee grounds (SCG). Our proposed process takes wet SCG through a drying and extraction process to extract the lipid content from the coffee grounds. This lipid content contains a high amount of free-fatty-acids which need to be treated in an esterification process before being sent to the transesterification section of our process. In the transesterification section, the extracted lipid oil reacts with an excess of methanol and a sodium hydroxide catalyst to produce fatty acid methyl esters (FAME) and glycerol. Downstream units then separate and purify the two main products. The only cost associated with SCG are transportation costs. Additionally, by recycling spent coffee grounds our project assists in preventing emissions into the atmosphere from decomposing SCG in landfills. With our plant located in Georgia near the border of South Carolina, we will be receiving wet SCG from two Starbucks roasting plants near our facility. With an estimated 1.2MMlb/week of wet SCG received from the Starbucks plants, the biodiesel production per year is 3.12MMlb.