While energy production from biomass has gained a fair amount of interest in the last years as a potential option of divesting from fossil fuels, it’s important to understand the whole picture of biomass energy conversation. At least that’s according to a new study published recently in Bioresource Technology Reports from Tony Grift, a professor of Agricultural and Biological Engineering in the College of Agricultural, Consumer and Environmental Sciences and the Grainger College of Engineering at the University of Illinois.
The study focused on the efficiency of miscanthus giganteus and sugarcane bagasse, both of which are popularly used as biomass for energy production. While miscanthus is known as an ornamental crop, it produces a large amount of biomass and grows easily without much nitrogen so it is a favorite for energy production; sugarcane bagasse, meanwhile, is produced after the sugar is extracted from sugarcane.
Researchers collaborating from the University of Illinois and the University of California at Berkeley analyzed the energy expenditure of harvesting and preprocessing materials, as well as the efficiency of converting the biomass to glucose, which can be made into ethanol fuel. In other words, the researchers wanted to get a good look at not only how much energy is produced, but also how much energy was needed for that production.
To do so, they relied on inherent heating value, or PIHV, which calibrates the amount of energy that goes in and comes out. "It tells you that you have a certain amount of biomass, which contains a certain amount of energy. How much energy do you spend on processing? You don't want to spend more than 5% of the total energy value," Grift says.
Understanding which steps of preprocessing expend the most energy may seem like a small part of the equation, but when scaled up, they can have significant impacts in improving efficiency. The researchers say more investigation is needed in order to fully understand how energy production from biomass can best be optimized.