Amy Macaulay
The recent repurposing of an old, abandoned meat packing plant has brought new life to a distressed neighborhood while also providing solutions to common waste management issues. The Plant, an urban agriculture venture in Chicago, will be doing its part to divert 5,000 tons of organic waste, normally destined for landfills, to an onsite anaerobic digester. The digester, a horizontal plug-flow, high-solids system supplied by Eisenmann Corporation, will process the waste into biogas to be converted to electric and thermal energy. The use of anaerobic digestion technology will help The Plant to achieve its goal of becoming a zero waste, zero net energy and completely self-sustaining facility.
The Plant
In July 2010, entrepreneur John Edel purchased an empty factory in south Chicago’s historic Back of the Yards Neighborhood, which in the early 1900s was the world’s biggest industrial complex for meat processing. However, Edel had very different plans for putting the historic structure to new use—plans that ultimately involve waste diversion and organic waste to energy through anaerobic digestion. In its crumbling halls he founded The Plant, an urban farm comprised of agricultural and various small food businesses.
The Plant is a new kind of non-profit organization housed in an old, 93,500 sq. ft. building. The premise here is a truly self-sustainable system featuring repurposed building materials, food production, economic development and renewable energy created onsite. They are connecting outputs of one business to the inputs of another to harness the value from materials that most people would throw away. Driven by a desire to tackle environmental and social problems, The Plant’s mission is to promote closed-loop food production and sustainable economic development through education and research. This will include fighting the food desert epidemic, creating green jobs, diverting waste from crowded landfills, and providing renewable energy to reduce their carbon footprint.1
Many urban areas face a significant problem with distressed industrial neighborhoods like the south side of Chicago and the former stockyards. Today, these once-flourishing manufacturing districts often have become both visually and economically draining on a city. The U.S. Department of Agriculture has also determined most of these areas to be food deserts, defined as urban neighborhoods and rural towns without ready access to fresh, healthy and affordable food. People who live in these areas, estimated to be 23.5 million Americans, experience physical and economical barriers to accessing healthy foods, including the availability of nutritious foods, the affordability of foods or just a lack of access to food retailers.
Urban farms like The Plant provide a way of addressing food deserts of this kind. Making full use of available space, including roofs, agricultural produce including vegetables, grains and fruit are cultivated on several floors. The Plant is also currently home to an aquaponics facility which combines food hydroponics with fish-farming. Projects like this are often made possible by current national and local government programs and efforts. There are numerous grants available and ordinances being developed and passed that support the development of sustainable programs and strategies seeking to eliminate food deserts.
Zero Waste Strategy
John Edel’s vision goes far beyond merely supplying the local population with nutritious food options. By offering low rent and low energy costs, The Plant plans to incubate small food-production and retail businesses (currently a bakery, kombucha brewery and shared commercial kitchen). This is projected to create 125 new, green jobs and start-up opportunities, raising the area’s economic growth potential.
To add even more benefit, the ecological principles underlying the project call for a zero waste and a zero net energy strategy. An additional goal to building the small food-production businesses is to establish a network of enterprises where the (waste) product of one serves as a resource for others. This self-sufficient, internal recycling system allows for the businesses to grow together while also successfully diverting waste. For example, grains from the brewery will feed the fish, solid waste from the fish will be used as nutrients for the plants and clean water provided by the plants will go back to the fish.
At the center of this unique concept will be the biogas plant, provided by Eisenmann Corporation and due to be commissioned in summer 2013. The biogas plant will use anaerobic digestion to convert 13 tons of organic waste products per day, otherwise destined for landfills. The waste, which will come from The Plant’s businesses and nearby food companies, will be turned into three by-products: compost-like solid fertilizer, non fossil-fuel based liquid fertilizer and up to 55 million cubic feet of energy-rich biogas. The gas will then be fed into the combined heat and power (CHP) system, in this case a repurposed jet engine, which will also be housed in the former factory. Its electric power yield of 200 kilowatt per hour (the equivalent needed to power 250 homes) will be made available to the businesses on site, while the heat produced will be used to heat the building.
Biogas Technology
Initiatives like The Plant present biogas plant manufacturers with a considerable challenge. Unlike digesters that use a low-solid, agricultural feedstock, the consistency and composition of this waste stream can vary greatly, much like that of food processing or municipal solid waste. The Eisenmann Biogas Green Waste Technology that will be used was selected for its versatile feeding system, capable of handling a wide range of waste material. The Plant will be able to turn a variety of organic wastes from a multitude of sources into renewable energy. The plug-flow digester designed to handle materials with high solids content. During digestion, the feedstock is continuously fed to the horizontal digester where a horizontal agitator mixes the substrates to ensure a homogeneous mixture and guarantee an optimal biogas yield. After the main digester, the substrate is passed to the post digester for a second digestion stage. This vertical stirred tank offers a top-mounted double-membrane gasholder to store the biogas before use. The system, custom designed for The Plant, provides maximum output in the available footprint for an urban environment. This technology is a critical component to the success and sustainability goals at The Plant.
Amy Macaulay is the Marketing Manager for Eisenmann Corporation. She can be reached at (815) 455-4100 or via e-mail at [email protected].
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