Foodservice Equipment & Supplies

AUG 2018

Foodservice Equipment & Supplies magazines is an industry resource connecting foodservice operators, equipment and supplies manufacturers and dealers, and facility design consultants.

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waste managment 80 • FOODSERVICE EQUIPMENT & SUPPLIES • AUGUST 2018 take solid food waste and transform it into soil amendment, more anaerobic digestion (AD) facilities are doing the same. They can create not only a usable fertilizer, but some are also able to capture methane gas from the AD process and convert that to energy for heating and even natural gas for more envi- ronmentally friendly fuel, according to the Water Environment Federation (WEF), a nonprofit educational foundation. With food waste being mostly made up of water, clean water by- product from AD systems can also be pumped back into water streams for use, which is especially invaluable in drought-risk areas, the WEF has stated. Companies such as WISErg, a Redmond, Calif.-based fertilizer company, has a similar, circular economy mission. WISErg takes wasted food, primarily from large grocery and big box stores and production facilities in Southern California, and transforms that waste into an organic, liquid fertilizer that farmers can use to enhance the growth of the same organic produce and other foods that the grocery stores will then eventually buy back. "The idea is that we can turn waste into a resource that the same industry can use," says Robin Sweere, PMP, CSCA, national account executive at WISErg. "We initially had the idea of going with anaerobic digestion but realized it wasn't as cost effective as our system. We had to figure out a way to turn our 'broth' into something of a higher value commodity." The "harvester," which looks like a large industrial refrigerator with a 5,000- or 10,000-gallon tank next to it, sits at the back of the store, where employees can load up to 350 pounds of material at a time. A digital userface allows the employee to select the type of waste they will load — from produce to meat and bones — which impacts the process- ing time and prevents system overuse of water and energy. The machine grinds, aerates and treats the material with WISErg's "secret sauce" that stabilizes the material and prevents rotting (unlike in traditional composting). That mixture then goes to WISErg's main production facility, where it digests further and breaks down with WISErg's pat- ented system. All current end-users are within 25 miles of the facility. The end result is a liquid slurry, or broth as Sweere calls it. Organic produce farmers use the broth in place of chemical fertilizers to naturally improve growth and yield. A second WISErg plant is underway in California. Although the company works primarily with grocers, larger foodservice institutions like healthcare facilities, universities and casinos continue to show interest in this approach, too. "The key is having a balanced diet of nutrients," Sweere says. "We wouldn't want a pizza place with just 10 pounds of pizza; we like to work with places that have a wide range of foods in order to help the plants grow stronger. I wouldn't say you are what you eat; it's more that you are what your food eats." The broth, Sweere insists, is more nutritious than, say, manure, which can be limited in plant nutrition because the cow has already taken and used those vitamins and minerals. Even if nonorganic compost makes its way into the sys- tem, the system will still break down the material to elimi- nate any outside pesticides and pathogens, ensuring use for certified organic farms. There's also full traceability for every batch and the farm that uses it. Some anaerobic digester systems have similar processes, such that they transform waste into a slurry that farmers can use to grow more food. But, if that slurry goes unused, as Shakman pointed out earlier, that loop hasn't been closed. Circulating Cooking Oil Oil is another foodservice industry material that operators can now recycle. With the advent of more advanced oil filtering and management systems and technologies, restaurants are using less and changing oil less frequently. And many of these same restaurants now send their oil to biodiesel producers, which then use it to create a more natural gas to power trucks and fleets while cutting down on environmentally-harmful emis- sions. Animal feed represents the other use for used cooking oil. While used cooking oil can be used for biodiesel, the main source for the natural gas comes from soybean oil from industrial agriculture operations. The Department of Energy defines biodiesel as "a liquid fuel made up of fatty acid alkyl esters, fatty acid methyl esters (FAME), or long-chain mono alkyl esters." Biodiesel is typi- cally blended with conventional diesel fuel in a 10/90 biodies- el/conventional diesel rate up to a 20/80 percentage blend. According to the Green Truck Association, almost 12 million Class 3 to 8 trucks are registered in the U.S., of which approximately 80 percent are powered by diesel engines. Vehicles that have the potential to be fueled by bio- diesel include light-duty and heavy-duty vehicles manufac- tured after 1993, according to the DOE. The main benefits of biodiesel are a relatively low impact on the environment. One big unanswered question remains: what is happening to the biodiesel after it goes to the open market? A variety of industries use biodiesel, and it can be challenging for restaurants to know who, perhaps, in the foodservice industry might be using that oil. There's plenty the foodservice industry can do, still. What if the chain restaurant or other large-scale foodservice opera- tor sending off its cooking oil for biodiesel could actually get some of that back for use in powering its vehicles, or at least get a credit? Could the foodservice industry specifically use that biodiesel to naturally power food distribution trucks? This is where the nuance of a circular economy comes in. "It's important not just to create a circle — any circle — but to maintain value through the transfers," says Shakman. FE&S

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