When Gene and Edna Hurst opened up shop behind their Thomasville, Georgia, home in 1967, they were acting on a vision that would play out for generations. Nearly 40 years and 350 employees later, Hurst Boiler & Welding Co. Inc., now run by four Hurst siblings—Tommy, Hayward, Teri and Jeff—operates a 314,000-square-foot boiler manufacturing facility in nearby Coolidge. There, a full line of solid waste, wood and other steam and hot water boilers and equipment are designed and made, a diverse variety of machines that has allowed Hurst to expand its reach to applications across the globe. Highlighting two projects completed stateside and south of the border, Hurst stands ready to solve unique challenges posed by the utilization of waste for energy. Global Reach One of Hurst’s most innovative and unique installations to date is in a town called Tequila. The Jalisco, Mexico, town is home to the country’s historic and renowned tequila producer Casa Herradura, a 140-year-old company that still operates on the site of its original, 19th-century Hacienda, but has striven for technological innovation and sustainability.  Herradura installed the first reverse osmosis plant in the country and two of its own wastewater treatment plants, as well as a series of projects to install state-of-the-art steam boilers to generate energy from waste biomass and biogas. Working in cooperation with Hurst Boiler and Calderas y Proyectos Ochoa S.A., the Hurst distributor for Mexico, Herradura installed a Hurst Hybrid Biomass Steam Boiler that can be fired with either the biogas generated via the wastewater treatment plant’s anaerobic digester, or by burning the organic agave waste produced via their production process. Custom engineered and designed specifically for Herradura’s processes, the equipment configuration incorporates a grinder, three-pass stainless steel dryer and material conveyor system to deliver the processed agave waste to the biomass boiler combustion chamber, where it is burned to produce steam. Annually, the boiler converts 81,000 tons of agave bagasse into process steam and more than 27,000 tons of compost, that can also be used in the agave fields and neighboring nurseries. Additionally, Hurst and Ochoa installed two Oilon Burners at the site. They are also fuel flexible, as they can burn both No. 6 and No. 2 oil, as well as biogas. Herradura has been able to realize a fuel savings of up to 70 percent by switching to biogas and biomass fuels, and achieved the projected ROI on the boiler project in 13 months. A more recent, equally innovative project Hurst highlights is its third poultry litter-fueled boiler project. Prestage AgEnergy of Clinton, North Carolina, is completing a 1600-HP installation. From fuel receiving through emissions, it is Hurt’s first system in the U.S. that has been designed and engineered specifically to be fueled by poultry litter. This cogeneration facility is scheduled to be commissioned mid-year, the company expects, and will support Prestage Farm’s turkey operations. Traditionally, litter has posed challenges to typical boiler systems, according to Charlie Coffee, solid fuel boiler sales for Hurst Boiler. “We are well aware of the many challenges and problems of litter as a fuel, which is why we spent an inordinate amount of time and resources making sure that we had measures in place to ensure success in the U.S. market,” he says. To mitigate the challenges associated with using this type of fuel, Hurst boiler strategically considered each aspect of the process, which includes the way litter arrives at the facility, material handling equipment and emissions. “The greatest challenge with the combustion of litter has been its low ash fusion temperature,” says Sam McLamb of Broad Energy Solutions, a Hurst partner. “Hurst manages the challenge of litter’s low ash fusion by utilizing enlarged furnace volume, two-stage combustion, and enhanced temperature controls throughout the boiler system. Additional features include upgraded soot blowers, increased grate area, water cooled furnace, and a two-pass, fire-tube boiler design.”  Hurst’s biomass boiler system allows facilities like Prestage’s to take advantage of the many unique benefits poultry litter offers. For example, the ash from litter is particularly rich in available potassium and phosphorous. “By concentrating these nutrients in ash, these systems can transform the potential risk of phosphorous regulation into an economic asset for companies,” Coffee says.  President Tommy Hurst says that while the company has been carefully evaluating the potential to use litter in its boilers in the U.S. market, one of Hurst’s solid fuel boilers in Guatemala began running almost three years ago on 100 percent litter, simply because it was the most cost-effective and reliable fuel. “Since then, two more systems have been installed and are providing steam to poultry facilities using only chicken litter,” he says.  McLamb adds that there are multiple projects in various stages both within and outside of the U.S., and drivers differ. “In the country, projects are largely driven by a combination of environmental concerns, fuel costs, and nutrient recovery in the ash,” he says. “Outside of the U.S., the availability of poultry litter and high costs of other fuels has been the primary driver.” Coffee shines some light on international development, pointing to the Southeast as an active region for these kinds of projects. “There are several litter-to-energy projects in development or under construction in the southeast,” he says, adding that while there is potential for an installation anywhere there is significant environmental concern about land application of litter, overseas markets have been leading the implementation of these types of power plants, primarily due to restrictive U.S. EPA regulations. “However, many states are beginning to enact energy policy mandates that require utilities to provide waste-generated power,” he says. “As the overall U.S. market now moves toward environmental sustainability and sees energy costs continuing to increase, companies and governments are both looking for viable alternatives to provide these solutions. It’s taken so long because we spent a lot of time in development and researching different technologies to make sure that the application and technology we were using would be successful.” Hurst is also currently engaged in securing funding for several jobs converting municipal solid waste to energy, particularly in Mexico and the Ukraine. “We are currently seeking ways to help bridge the gap between the viable projects seeking Hurst solutions, and the 17 Sustainable Development Goals and 169 targets which were announced as part of a new universal Renewable Energy Agenda by the United Nations,” says Dennis Dauphin, Hurst international sales manager. “These efforts have culminated in the drafting of several proposals presented to organizations associated with the UN such as the World Bank Group and the International Finance Corp. In doing so, Hurst has encouraged environmental stewardship through research and the implementation of new technologies for emissions control, energy efficiency, renewable energy resources, and other environmental and health concerns associated with these power generating plants and utility operations. This can reduce the operational costs of current facilities, and provide a return on investment from installation in new construction.” Author: Anna Simet Managing Editor, Biomass Magazine [email protected] 701-738-4961