This column by Los Alamos chemical engineer James Coons appeared in the Santa Fe New Mexican on Sunday, Jan. 1.
With the new year upon us, many beer lovers will be spreading the cheer at one of our great local brewpubs. As they hoist a tasty toast to new beginnings, not many revelers are likely to pause to ponder the effort that went into creating their brew.
The ancient craft of brewing has benefited from high-tech advances over the years, and now ultrasound technology is stepping up to help brewers simplify clarification of the hoppy refreshment. Ultrasound is better at selecting out particular sediments from the mix than filters or centrifuges, allowing brewers to remove the larger particles while leaving behind those that boost a beer’s traditional character.
The concept of membrane-free filtering came from a team of biofuels researchers at Los Alamos National Laboratory, who needed a way to remove water from soupy algae cultures. The microalgae, which are bred to be full of energy-dense hydrocarbons just like the liquid fuels used to power automobiles and airplanes, must be separated from their vast watery surroundings. The combination of ultrasonic standing waves — a wave that remains in place — and gravity can drop the algae particles to the bottom of a tank, where they become much more concentrated and favorable to extract.
Our ultrasound approach, called UltraSep, has many advantages over traditional filtration. It is safer than using high-speed centrifuges, certainly quieter and it produces much less waste than the filtering process.
UltraSep introduces silent ultrasonic waves that bounce back and forth across a tank, which forms regularly spaced pressure nodes at fixed locations, thus the term “standing wave.” Particles are trapped in the standing wave and gather at the nodes until they clump up and gravity pulls them to the bottom of the tank.
Read the story as it appeared in the Santa Fe New Mexican.