By Brian Levine
Food processing facilities face unique challenges with wastewater. Among the highest consumers of clean water, the more than 40,000 food processing plants across the United States and Canada generate wastewater with massive volumes of fats, oil & grease (FOG) from the animal fats and vegetable oils used in their operations. The EPA and municipalities monitor and set limits on the level of contaminants industrial processing facilities can discharge. To meet compliance, industrial wastewater streams must be treated on site before the effluent is discharged to treatment plants.
As a result, food processing plants are beginning to design extensive treatment systems at the source to pretreat their greasy wastewater before discharging effluent into municipal pipes. These systems give companies greater control over their FOG discharges and associated costs. With the right systems, food manufacturers are finding that they not only reduce operational costs, but also turn the formerly high cost of waste processing and disposal into a value stream.
Traditionally, food processors choose to blend their greasy waste with polymers or other chemical additives, use it for composting, or send it to the landfill. However, emerging clean technologies are now helping food manufacturers affordably turn their massive supply of wash down water into products for further consumption. Companies now have options to process greasy waste in an ecofriendly and cost-effective way, thereby reducing their carbon footprint while lowering operational expenses and even discovering new sources of revenue.
One of the systems the food processing industry is implementing is Greasezilla®, a hydronic thermal FOG separation system originally designed for wastewater treatment plants and independent haulers. By applying heat to separate FOG into well-defined layers of brown grease, batter and effluent water, the system separates up to 40,000 gallons of raw grease trap waste per day without any added costs for additives, additional processing, blending or fossil fuels. Additionally, the system reclaims resources that can be used or sold, providing new revenue streams for food manufacturers.
Grease to Green
Once heated, the system generates distinct layers. The first layer is very low moisture, high FFA Brown Grease advanced biofuel (ABF) offtake that is a fuel grade drop-in substitute for No. 5 or No. 6 fuel oil. The offtake is a marketable commodity, ready for boiler use without further processing. The quality of the ABF, with a moisture level of less than one percent, also makes it an ideal, reactor-ready feedstock for the growing number of emerging biodiesel conversion technologies. Also, the hydronic thermal separation system operates on only five percent of the ABF it produces.
The next layer of batter, or sludge, is the organic material left over after the Brown Grease is separated. Comprising organic food waste solids, this material is now a balanced, homogenized substrate input source for anaerobic digestors. Increasingly recognized for its ability to reuse waste as a resource, anaerobic digestion produces biogas that can be used as fuel or upgraded to a natural gas substitute. The solid digestate material can be used as a soil conditioner orfertilizer.
Once the Brown Grease and batter are removed, the remaining water, now pasteurized and nearly free of all suspended solids, is safe for discharge to municipal treatment facilities.
Keeping up with increasingly strict environmental and municipal standards can strain the operational budgets of food manufacturers, restricting production expansion and business growth. Clean technologies are now providing companies with simple, low-cost options to reduce waste and expenses. The growing demand for quality biofuels and feedstocks provides food manufacturers with an opportunity to find value in their greasy waste. By separating their grease waste with ecofriendly processes, companies can replace grease disposal fees, municipal surcharges and costly chemical usage with new revenue streams and a smaller carbon footprint.