From Trash to Treasure

Features - Other Recyclables

Engineered fuel is just one of the many products that the Medina County Central Processing Facility and Steve Viny’s miniMRF technology can produce from residential garbage.

December 29, 2010
Kristin Smith

Nearly 18 years ago, Steve Viny built the Medina County Central Processing Facility (CPF) in Seville, Ohio. The facility is perhaps the longest running mixed waste processing facility in the U.S. and is still in full operation today.

Since there was no residential curbside recycling program in place in Medina County in 1993, the facility was designed to sort and recover items like newspaper, steel and aluminum cans, white goods, plastic bottles, wood, organics and yard waste from mixed solid waste—items that can either be recycled or made into other products.

Ever since the facility opened, every bag of trash from Medina County has been directed to the CPF through flow control where it is processed to extract recyclable commodities and compostable materials, which are sold, as well as a coal alternative product called engineered fuel (EF)—all greatly reducing the volume of waste destined for the landfill.

“In Medina County, you’re a recycler whether you want to be or not,” is how Viny, the CEO of Cleveland-based Envision Holdings, describes residents whose garbage is processed through the system.

Studies indicate that almost 50 percent of aluminum cans in the U.S. are not recovered for recycling. A recent report concludes that in 2009 27.8 percent of PET bottles were recovered for recycling—an increase from the previous year. While recycling rates may be improving, many recyclable items still ending up in the waste stream, even though in many cases consumers have access to recycling programs.

According to Viny, because so many recyclables are disposed of with trash, the model used in Medina County also can work in areas with curbside recycling.

The Medina County CPF has not missed a single day of operation in its almost 18-year existence, processing an estimated 500 tons per day of municipal solid waste (MSW). The plant still uses all of the original processing equipment. Viny attributes the equipment’s longevity to a system that combines two daily production shifts and a nightly third shift that cleans and maintains the facility.

FIRST GENERATION — MEDINA COUNTY CPF

In Medina County, 100 percent of residential waste is delivered to the Medina County CPF. The CPF is housed in three rooms at the 71,000-square-foot facility. First, the waste is transferred from the tip area to an infeed conveyor belt. Workers in the primary sort room remove recyclable items typically outside of garbage bags, such as cardboard, newspaper, white goods, wood and yard debris. Next, machinery breaks open the trash bags, liberating the contents.

The system then screens out the fines, or the small-sized fraction, from the waste stream, which consists of yard waste, food waste, small paper products, glass and small metallic objects like nails and household batteries. The small metallic objects and batteries are recovered and sold. The remaining fines are composted at the facility’s Class 1 Compost Facility and screened to produce alternative daily cover (ADC) and other compost products. The clean wood products are shredded, dyed and sold as color-enhanced mulch, and yard debris is composted, shredded, screened and sold as compost and natural mulch products.

Once the fines and bulky items are taken out of the stream, the remaining material continues through the conveyors. An electromagnet pulls the ferrous metal out, and an eddy current separator removes nonferrous metal objects. The remaining material is conveyed to a second sorting room, where different grades of paper and plastic are hand-sorted and subsequently baled.

According to Envision’s website, the Medina County CPF has processed an estimated 4 billion pounds of solid waste and is the cornerstone of the county’s solid waste management program. Despite the volume and the heterogeneous nature of that waste that has been sorted, the facility claims that it has never had a load of recyclables rejected, as it makes clean bales.

During the final stage of processing at the Medina County CPF, EF is made. The fuel product is made on the back end of the system using a proprietary air system with a ballistic separator that removes the heavy material. It is a product that is free of glass, metal and heavy plastics, according to Envision. What is left is a combination of mixed paper and plastic film, which is baled for use as an alternative fuel in utility boilers.

The EF that the Medina County CPF produces has been tested for more than a decade.

NEXT GENERATION – THE MINIMRF

Recently, Viny introduced his next generation mixed waste processing system, called miniMRF.

“Even in areas with curbside recycling, it is a very effective program,” Viny states.

He says officials are amazed at what can be recovered from the trash a mini-MRF. For example, in Montgomery County, Ohio, the miniMRF recovers a large amount of steel and aluminum cans that residents still continue to put in their trash despite the residential recycling program.

Viny describes the miniMRF as the “MRF (material recovery facility) of last resort.”

The system was coined as a miniMRF because of its high production rate despite its small physical size.

MiniMRF LLC is the company that was formed as a joint venture between Viny and the world’s largest producer of aluminum rolled products—Novelis Inc.—to deliver and implement mini-

MRF technology in new or existing transfer stations and other facilities. According to Viny, the miniMRF system consists of three trailer-mounted, completely assembled modules and can be delivered and operational in 20 weeks. This is a vastly different approach than the traditional design and custom build philosophy used on virtually all major MRFs today, he claims.

“With miniMRF, there are no requirements for special foundations, no field construction costs and the time required from placing an order to commencing full operation is greatly reduced when compared to a traditional MRF,” Viny explains.

Just like the Medina County CPF, the miniMRF is designed to remove ferrous and nonferrous metals, glass and organics and an EF fraction, to achieve a high rate of landfill diversion. MiniMRF can be used as a standalone system, as a front-end processing system for conversion technologies like gasification or pyrolysis or as a front-end processing system for waste-to-energy (WTE) systems.

In the case of WTE, companies can beneficiate their processes, according to Viny, using the technology. The mini- MRF can be used to remove unwanted materials prior to combustion in the WTE boiler. For example, ferrous and nonferrous metals cannot be combusted because they will melt and plug up stoker grates in WTE systems. In addition, metals don’t provide calorific value and when recovered in the bottom ash of a WTE system decline in value.

“Why put in metals and scrub them out of the back? It makes more sense just to remove them up front,” Viny says.

Glass can slag in a boiler and organics, with their high moisture content, have parasitic value in a WTE boiler, according to Viny. The miniMRF takes out glass and organics up front to be made into compost instead of going into a boiler.

Processing waste in a miniMRF gives the EF its best value and puts the boiler in its best light, according to Viny. EF is being tested in a market that has no tolerance for rigid plastics. Heavy plastics, explains Viny, can be a precursor to dioxins. That is why the miniMRF’s air system is designed to eliminate them.

The EF can be injected into existing coal-fired boilers, cement kilns or lime kilns, often without modification, according to Viny, who says EF burns cleaner than coal.

Viny points out that chlorine is very corrosive when combusted in a boiler and that other waste conversion technologies like gasification frequently do not remove chlorine up front. Conversion technologies may change the physical state of the material from a solid to a gas, but it does not change the fact that toxic chlorides are still present in the gas.

“We scrub them out of the waste stream, so the boiler or conversion technology never sees them,” explains Viny of the miniMRF process.

In four large scale test burns of EF, Viny reports, “We haven’t had degradation of stack emissions with their existing back-end structures.” In many cases, he adds, “emissions actually improved.”

The four test burns that have been conducted since the late ’90s have all been successful, Viny reports. Two more test burns of EF are scheduled to take place in the next 90 days.

Quite a few entities have expressed interest in the product, according to Viny, which he says is an is an inexpensive renewable power source that burns cleaner than coal.

Viny was recently recognized for his contribution to the solid waste industry for both the miniMRF technology and the creation of EF. He was named the 2010 Solid Waste Innovator of the Year by the Solid Waste Association of North America (SWANA), Ohio Buckeye Chapter.

FUELING THE FUTURE

Viny says he is eager for EF produced at the Medina County CPF to replace coal in coal-fired boilers as a source of fuel. Recent legislation that will recognize EF as a product other than waste could be the break he has been waiting for.

The Resource Conservation and Recovery Act (RCRA) rule clarifies which nonhazardous secondary materials are solid wastes when burned in combustion units.

The nonhazardous utilization rule, in Viny’s words “breaks down barriers.”

Of EF, Viny says, “People want to buy it.” But until this new ruling, EF has been regulated as trash in some cases.

This new rule no will no longer define the alternative fuel EF as waste, making it easier for potential customers to be able to use. Viny says the new nonhazardous utilization rule and new standards will bring attention back to the “dirty MRF” but he is quick to mention that this “doesn’t mean the end of curbside recycling.”

Viny admits, “We live in a coal-dominated society, and we will be for decades.” However, he says the revision to the RCRA rule being considered by the Environmental Protection Agency “is a game changer, and we are excited.”

The author is assistant editor of Recycling Today and can be reached at ksmith@gie.net