A collaboration between Los Alamos National Laboratory (LANL) and Jenike & Johanson, a bulk solids storage company, and funded by the US Department of Energy (DOE) Bioenergy Technologies Office (BETO) through the Feedstock-Conversion Interface Consortium (FCIC), has developed new technologies, called Smart Transfer Chutes, with integrated acoustic moisture sensors that greatly improve the operational reliability of biorefineries.
Helping to strengthen the economic viability of biorefineries in the production of alternative fuels derived from biomass is critical to decreasing the use of fossil fuels and mitigating carbon dioxide (CO2) emissions. Just as fossil fuels require refineries, so do biofuels.
While these integrated biorefineries process a variety of biomass materials, a major source is corn. After the edible kernels are removed, farms are left with “stover,” byproducts such as leaves and cobs.
In the past, these were burned as waste. But they can also be processed into biofuels, everything from ethanol for cars to polymer additives for rubbers and chemical commodities, all of which would normally use fossil fuels.
Eliminating feedstock clogging
A major issue during processing, however, has always been moisture-laden stover, which can clog conveyors and chutes that direct the material around the refinery. During a clog, the refinery needs to be stopped and that moisture-laden stover needs to be removed by hand.
The Achilles heel of biorefineries is operational reliability. Currently, the operational reliability of biorefineries is estimated to be around 30 percent, meaning that for 70 percent of the year they have to stop operation. To be economically viable, the operational reliability needs to be around 90 percent. In other words, biorefineries have an efficiency problem said Troy Semelsberger, a senior research scientist at Los Alamos National Laboratory.
Smart Transfer Chutes is eliminating these moisture-related stoppages through the use of an in-line acoustic moisture sensor capable of continuous, real-time monitoring. The acoustic moisture sensor works by directing soundwaves through the corn stover as it is being processed.
If moisture contents exceed those that are known to cause stoppages, it sends a signal to another device.
This is where the innovativeness of Jenike & Johanson comes in with their “Smart” chute technology. When the acoustic sensor deems the stover too wet to process—a possible clog risk—a computer engages a track change on the conveyor belt, redirecting it to be further dried.
These technologies actively remove ‘monkey wrenches’ from entering the process. That means biofuels could soon become a cost-effective product, one that’s created from a byproduct, and that doesn’t require extracting fossil fuels, said Troy Semelsberger.
