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Because of space—and regulation—changes for dealing with flow control are on the move. By Lynn Tilton Transfer stations used to keep a relatively low profile. They were simply the means of storing waste until it could be taken to the landfill. The goal used to be to keep transfer stations either within budget for municipal operations or at a profit for privately run outfits. Now when it comes to handling waste, it seems the US is following European countries in finding solutions. This can affect changes in the primary market for equipment manufacturers.
“I see a regulatory trend in this country,” says Madison Burt, national sales manager for Weima America in Fort Mill, SC. “For example, in Germany, if you take anything into the landfill, you have to find ways to deal with all that waste.” The principal concern in European countries is that there simply is no room for landfills or for material recovery facilities (MRFs) that can’t operate in tight spaces. A market has to be found for all products they treat. More and more, US metro areas face similar challenges. Burt comments, “Here during the ’80s there was a push for turning waste into energy. That involved grants. Despite grants, operating a transfer station/MRF simply as a source for energy was unsustainable.” Looking at older technology, he notes, “Hammermills used to require significantly higher-horsepower motors. There was a lot of product jamming along with higher energy costs.” Also, the demand for processed material was much less at that time. Now it seems there’s a market for just about anything. The need is for further reduction, regardless of the product involved. Today’s technology includes single-shaft shredders, such as the ones supplied by his firm. The shredders can turn waste into finished products quickly. This requires accurate sorting of materials brought to hybrid MRFs where high-volume materials can be significantly reduced and turned into marketable products. When land space is tight, transfer station/MRF hybrids (aka dirty MRFs) can transfer unusable material to landfills for subsequent sorting and processing. In areas where there’s lots of land, even older landfill technology usually is sufficient for dealing with local waste. Burt continues, “Now the need for processing is to compact raw products quickly. MRFs need to use equipment with low downtime. For longevity and productivity, maintenance is crucial. For instance, while it takes four hours to deal with maintaining our equipment, the other 20 hours can be a dump-and-run operation. This allows hybrid operations to deal with other challenges, knowing the machine will accurately follow the specs for the type of material it’s designed to deal with, such as paper, plastic, wood, and textiles.” The ram pushes that specific material toward the fixed-speed rotor at whatever rate it can handle. He recommends that continuously operating transfer stations and MRFs have two lines in place. Then, when waste reception is high, so is processing. When reception is low, just one line is needed. This makes economical sense. Burt adds that shredders producing from a single line can handle 5–20 tons per hour. Equipment can be located at the MRF or at a product-specific plant. “Three primary audiences are power plants, paper mills, and cement plants. All three have the permits needed to burn waste. There has been a significant increase in recycling since our Germany parent company, Weima, entered the US market. Whether it’s a public or private operation, more awareness of regulations involved—as well as developing markets for its products—has a lot to do with success.” Burt sees private markets as the principal focus for manufacturers—at this time. Speeding Waste Movement Speaking for Hallco Manufacturing in Tillamook, OR, Vice President Kevin Pike comments, “Another help for hybrid MRFs is curbside sorting. We offer a split rear-loader that applies an 80-to-20 split. This gives a cleaner stream. While MRFs are set up to sort out three to four different kinds of recyclable material, the nature of the industry is to make it feasible to recycle paper.” He adds that the principal items to presort are paper, milk jugs, other plastics, and metal, both aluminum and ferrous. “Non-recyclables are sent to the landfill. Today’s transfer station does more than store waste for hauling. There are more and more uses for profitable recycling, so the traditional transfer station has become both a place to haul waste and a place to pull out recyclable material and process it onsite so it can be prepared for users of the recycled material.” He points out that separating aluminum from ferrous metal is simple. All that’s needed is a magnet placed over the receiving bin. “Material recovery varies according to how receivers manage their MRFs. Here in Oregon 10% of waste material is recycled. This includes paint, sheetrock, et cetera. There are a lot of state and federal projects. If the price of recycled tin is down, for example, subsidies can help cover any loss in order to keep tin in the recycling stream. But economics make some products unprofitable to sort and utilize. Glass, for example, is a tough one to remove. “Here in Tillamook, residents have three cans and a box for curbside collection. Domestic garbage goes in one; cardboard, paper, and plastic go in another; and yard debris goes in the third. The box, about the size of an apple crate, is for glass. Four different trucks stop at my house every Monday.” Collection fees reflect the cost of sending that many trucks to the same address. Whether private or municipal, waste collectors utilizing the split-load concept can reduce the number of different vehicles needed for meeting curbside presorting regulations. At the same time, equipment suppliers need to know well the specific equipment needed for potential customers. Pike, who has 23 years of experience as a designer and builder of MRFs, points out, “There are no cookie-cutter MRFs. So many factors are involved. Basically, plastics require three cycles for proper sorting and treatment. So do metals. But paper can be handled with just one cycle.” He adds that states also seek other means for dealing with the volume of waste to encourage citizens to be more aware of the need for recycling. “For instance, we’re a fairly green state, so there’s a 5-cent deposit on every beer and soda bottle. And efforts are afoot to include water and every other beverage container. “Older MRFs are trying to accommodate recycling, and they’ve got to do it. It is hard to add material recovery systems to those. Usually that’s because they simply don’t have the room to expand the operation. But if they can pull items out of the wastestream they will have less to take to the landfill. This will help cut the cost of fuel.” But where does all this recycled material go? “One perception is that as metal prices rise, so does theft. A cure for that is to have metals baled right out of the collection stream so they’re too heavy to take.” This solution allows hybrid owners to send their recycled materials to the highest bidder, including other countries.
Science and Mechanics Most transfer stations begin with a single-stream system and go from there as demand for other products justifies the move. “Single-stream includes a mix of newspaper, mixed paper, and such containers as glass, PET, HDPE, aluminum cans, and tin cans. Sometimes there are various levels of residential OCC mixed in with this stream,” explains Dave Guyton, sales manager for Hustler Conveyor Co. in O’Fallon, MO. He continues, “Typically this material mix is pushed from a tipping floor onto metering in-feed conveyors and transferred across a presort station where OCC and trash are manually removed. Then the material is transferred across a primary screen where the newspaper [‘overs’] is automatically separated from the mixed paper and containers [‘unders’]. The unders stream materials are then transferred to a secondary screen that separates the mixed paper from the containers.” Typically, newspaper and mixed paper will be baled, while containers are transferred to a separate processing line. “If the percentage of OCC is high enough, a separate screen for automatic OCC removal may be utilized and is positioned in front of the primary screen,” Guyton explains. “Prior to this container processing line, the material will transfer over a fines removal screen to take out the broken glass and other 2-inch or smaller materials. Then the containers are separated either manually or automatically, depending on customer preference.” When a MRF employs automatic separation, a cross-belt magnet is used for removal of the tin cans and an eddy-current separator helps remove aluminum cans. Optical sorters remove the various grades of plastic. “Although six or seven years ago single-stream processing was most prevalent on the West and East Coasts, we now see it working its way to the Midwestern states,” he says. “As technology improves and costs for this automated equipment decline, these systems are becoming affordable to the mid-sized processor. Hustler conveyors help MRF operations handle capacity ranges from 10 tons per hour up to 50 tons per hour.” Phasing Out Grants for Power Plant Fuel Transfer station/MFR operations can solve that dilemma by increasing the technology of their operations so their fuel products become more competitive. Taking on new technology can be costly in the beginning. Many may remember that when flat-screen computer monitors first came out they required a four-figure investment. Now the same technology can be had for a tenth of the initial cost. The same is true when power plants began seeking recycled material as a fuel source. Says Randy Baerg, president of Warren & Baerg in Dinuba, CA, “In the past, it took grants to make generating alternative fuel for those plants in order to pencil out the cost of production. Cubers can supply 13,000 Btus per pound with burnable waste, which puts them in the range of more traditional power. For instance, depending on the grade, Btus in coal range from 10,000 to 14,000 per pound.” Baerg, who has been with the family operation full time for 26 years, adds, “Equipment needed for this includes a conveyor and a metering system to properly supply ground material. Processing capacity for our 300 Cuber, for example, can range from 6 to 9 tons per hour.” When market prices range from $50 to $60 per ton, hybrid operations can use the concept to create an alternative marketing product. A small footprint makes it possible for crowded hybrids to boost recycling sales as they up the range of burnable waste by including yardwaste and other types of wood in their processing. “With higher fuel costs and increased tipping fees, the answer is to increase the range for handling burnable waste and to lower operating costs by trucking out material that is denser than ever before. At this time, it seems that hybrids in areas that are a little busier call for more cubing. At the same time, city and county operations are more likely to add this process to their facilities.” But Baerg doesn’t rule out private MRFs checking the numbers involved to see whether using the technology would be cost-effective. “It takes just three to five working days for operators to be trained and running. The equipment is 75% to 80% automated. You need just one person there watching the control panel. It’s one way to take more stuff out in less time.” That’s why it’s becoming more profitable to use power plants as yet another way to focus on selling waste rather than merely trying to get rid of it. Versatility Helps MRF Hybrids Keep Growing After commenting that the company’s subsidiary, Builtrite Handlers, can answer needs from single- to triple-stream, he points out, “But the principle of sorting out recoverable products remains the same. There’s still waste that will have to be trucked to the landfill. It’s still a chore to remove goods that a hybrid isn’t prepared to deal with. For example, a single-stream transfer station/MRF may not be prepared to pick out things such as water heaters left on the tipping floor.” That’s where a stationary electric crane can be an answer. “Those cranes are picking up various things not going through the sorting line, and those materials vary from MRF to MRF. A stationary electric-powered crane not only helps speed the refuse flow, but there’s less noise and no pollution, and power to operate an electric crane costs just 10% of fuel-using machines.” Looking back on 30 years in the industry, Andersen comments there was a time when everything went to the landfill. But as space has become tighter and tighter, especially in East and West Coast states, regulations relating to waste require more and more types of materials be recycled. Andersen explains that governments within such states as California, are requiring documentation of everything being recycled, whether it’s glass, paper, plastic, etc. “This is done on a percentage basis, especially where a grant is involved. Agencies want to make sure those receiving grant money are most effectively dealing with the waste that’s tied to the grant. Those winning the grants have to show they are gaining on recyclables on an annual basis.” Whether or not grants are involved, he comments, “it makes economic sense for hybrid MRFs to run as economically as possible to add in equipment that will help them broaden their category of recyclables. “What goes to the landfill, such as tires, will likely be processed there,” he explains. “As traffic to the hybrid increases, the need to economically yet swiftly sort and package recyclables for market grows.” He notes that the original strategy 30 years ago was for a transfer station to help get rid of garbage by stockpiling so truckloads were at volume capacity before traveling to the landfill. Then about 20 years ago recycling began to be another element. In the past decade, municipal areas have gotten even more serious about the need to recycle to save land space. He says this is especially true in the District of Columbia; in St. Paul, MN; in San Francisco and Oakland, CA; and in the Dallas–Fort Worth Metroplex. Andersen emphasizes, “Recycling is the prime strategy.” If a privately owned hybrid MRF is going to win contracts, it must at least reduce the cost of operation to keep tipping-floor fees at an attractive level for users of that particular MRF. The same goes for municipal or multiple-county operations. Whether they work at public or private hybrid MRFs, managers have to find ways to deal with the increasing flow of waste. “They must become more and more sophisticated in the products they can sort and recycle for market. The goal is to reduce the cost for getting garbage out of town.” Profitability is essential to both public and private hybrid MRFs. To successfully boost the ability to recycle more and more products in order to extend the life of landfills, Andersen reports, “One requirement is to invest in equipment that will make it possible. For example, we have six of our stationary cranes in the DC area alone.” New York and New Jersey both have run out of landfill space so they have to transfer un-recyclable loads to out-of-state locations. He concludes, “Garbage isn’t going away. We will always have to deal with it.” Lynn Tilton writes on land and building issues. MSW - November/December 2007
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