In the central western Mexican state of Jalisco, the process of distilling tequila is a long-honored tradition, so much so the United Nations Educational, Scientific and Cultural Organization named a 34,658-hectare site between the foothills of the Tequila Volcano and the valley of the Rio Grande River where blue agave, the base ingredient of tequila, grows a World Heritage Site.
Because of pollution, insufficient water, and other environmental factors, agave fields in Mexico are diminishing rapidly. Some tequila distillers are taking notice and working to make their production of the spirit as eco-friendly as possible. One such distiller is Tequila Herradura in the town of Amatitán.
The production of tequila is very water-intensive—for every gallon of tequila produced, there is 18 gal. of liquid waste. The waste is so acidic that, when released without treatment, it makes soil unfit for farming. By installing Mexico’s first reverse-osmosis plant, Tequila Herradura reduced manufacturing-generated sewage waste by 70 percent. Filtered, treated water is recycled for use in cooling towers, for cleaning, and for irrigating agave plants and lawns.
Working with Hurst Boiler & Welding Company Inc. and Calderas y Proyectos Ochoa S.A., the Hurst distributor for Mexico, Tequila Herradura installed a waste-to-energy process. A Hurst 800-hp hybrid biomass steam boiler is fueled with either biogas generated by a biological anaerobic reactor as part of wastewater treatment or organic agave waste resulting from production. Through combustion of those materials, the boiler generates high temperatures that turn water into steam for the distiller’s industrial process or energy cogeneration.
The technology can be monitored around the clock from the Hurst plant in Coolidge, Ga.
Along with the boiler, Hurst and Calderas y Proyectos Ochoa installed two Oilon burners capable of burning both No. 6 oil and No. 2 oil as well as organic biogas. The system provides 12 percent of the energy utilized in the tequila-production process.
Custom-engineered and designed for the Tequila Herradura manufacturing and disposal process, the boiler-equipment configuration incorporates a grinder, a three-pass stainless-steel dryer, and a conveyor system for delivery of processed agave waste to the boiler combustion chamber. This allows Tequila Herradura to seamlessly convert agave bagasse into process steam as well as compost that can be used in agave fields and at neighboring nurseries.
With the help of Hurst and Calderas y Proyectos Ochoa, Tequila Herradura has become a model of clean-energy manufacturing, ensuring the agave bagasse and process-waste material it generates is separated, utilized, and recycled. Additionally, Tequila Herradura has been able to realize a fuel savings of up to 70 percent by switching to biogas/biomass, realizing a return on its investment in the boiler project in just 13 months.