Sandia Works with New Mexico Small Businesses on Innovative Recycling Methods

Sandia Works with New Mexico Small Businesses on Innovative Recycling Methods

Agency: 
Dept. of Energy

Along Route 66 in rural eastern New Mexico is a defunct ethanol plant in Tucumcari. Still hanging inside the building, calendars from 2010 mark the year it closed, and six massive fermentation tanks—each one 35 feet tall and 55,000 gallons—sit empty.

Drought has depleted local corn harvests that were supposed to serve as feedstock, rendering the facility economically useless and spoiling two attempts to reopen it. A third try began in 2016 when Tucumcari Bio-Energy purchased the plant. This time, says the company, things are going to be different because it’s not going to use corn.

Through New Mexico Small Business Assistance (NMSBA), Sandia National Laboratories is solving technical challenges for Tucumcari Bio-Energy and, in a separate project, helping a cohort of companies led by PJ Woodlands figure out how to market new composite materials made from forest slash.

Both companies are pursuing innovative ways to recycle waste, and both projects were among ten recognized by NMSBA this year. In 2017, the state of New Mexico, along with Sandia and Los Alamos national laboratories, invested $4.6 million helping 346 small businesses in 28 counties through the NMSBA program. Since its inception in 2000, the program has helped 2,797 businesses in all 33 New Mexico counties.

Sandia assistance is advancing both companies’ plans. Tucumcari Bio-Energy has reduced its financial risk and can pursue financing to reconfigure the plant. It is currently pursuing private investors and Department of Agriculture-backed loans. PJ Woodlands now can market its product and negotiate financing. It is also negotiating a site for its new production factory.

Thousands of gallons of (simulated) manure

Instead of corn, Bob Hockaday, president of Tucumcari Bio-Energy, has grand plans to fill his plant’s fermentation tanks with manure, which is very abundant around agricultural Tucumcari, to produce and sell methane-based natural gas. The product is designated a cellulosic biofuel under the Renewable Fuel Standard, which entitles producers to certain federal benefits for helping reduce greenhouse gas emissions. If the company turns a profit, dozens of closed and idle ethanol plants around the country could replicate the model and reopen their doors as well.

To turn manure into fuel you have to churn and carefully heat a slurry—Hockaday affectionately calls it “witch’s brew”—of water, manure, digestive bacteria, waste whey from cheese, and other ingredients. If the brew doesn’t mix evenly, it can overheat and boil over like a foul pot of spaghetti. Even if small areas inside the tanks get too hot or too cold, the bacteria, which ultimately produce the methane, can die or go dormant, respectively.

Perfecting the process through trial and error would have been too costly so, Hockaday explained, “We said, ‘Let’s go and use some science on this,’” and they applied to NMSBA.

“Some of the best fluid dynamics modeling is done at the national laboratories,” according to Hockaday. Fluid dynamics is the study of how liquids and gases move.

Liquid nuclear waste simulations

Sal Rodriguez, a nuclear engineer at Sandia, led the effort to identify potential trouble spots in the tanks before adding even a drop, or a plop, of slurry. He used computer software similar to that used to simulate liquid nuclear waste at sites in the northwestern U.S. This mapped out how slurry will circulate inside the tanks when the mixing propeller is spinning, hot fluid is rising, cold fluid is descending, and methane gas is bubbling to the top. Rodriguez found areas that weren’t expected to mix well and showed Hockaday how to modify the tanks to minimize the risks of over- and underheating. Rodriguez also calculated the ideal temperature range to maximize methane production.

Rodriguez and Hockaday now are working together on the project’s second phase to perfect the computer simulation by adding more detailed physics.

“We’ve got the pieces. We’ve got the tools,” said Hockaday. “I think we can solve the problem.”

The project benefits Sandia, Rodriguez added, because it’s improving the lab’s software. Both Hockaday’s slurry and nuclear waste happen to share an unusual trait among liquids: both liquids thicken under pressure. This allows Sandia to use one to better understand the other. Improving the software, Rodriguez said, could in turn benefit any facility or institution that keeps or studies nuclear waste.

To read the entire Sandia press release, visit https://share-ng.sandia.gov/news/resources/news_releases/small-business-recycling-ventures-propelled-by-sandia-engineering/.

Category: 
T2 News
Region: 
Mid-Continent