Global scrap tire processing firm Genan uses some 40 motors or drives made by Hägglunds.
Denmark-based scrap tire processing firm Genan Holding A/S, which has operations in several countries, says Hägglunds hydraulic direct drives have been a part of its work since 1990, helping Genan convert scrap tires into crumb rubber and recyclable steel and textile fibers.
“Genan is the world’s largest tire recycler and producer of high-quality rubber,” says Daniel Pohl, a project manager with the firm. He says Genan’s plants take in end-of-life tires and process them so the firm’s output is roughly 75 percent rubber granulate or powder, 15 percent steel and 10 percent textile fibers.
The company opened its first plant in Viborg, Denmark, in 1990, and is now a multinational business, having expanded first to Berlin in 2003 and later to two other German cities. The firm opened a plant in Houston, its first non-European site, in 2014, and now also has a plant in Portugal. In total, Genan now has six plants worldwide, with a combined intake capacity of nearly 400,000 metric tons per year.
Genan says with their built-in resistance to shock lock loads and their ability to start, stop and reverse as many times as needed, Hägglunds systems have been a logical choice to be used in its tire shredders and other processing equipment.
“We at Genan have designed all kinds of cutting machines ourselves,” says Pohl, saying these machines create what he calls exceptionally clean and uniform products. The company’s recycled rubber can be used in industrial rubber products, paints, plastics and road paving, and its cryogenically milled rubber powder can replace virgin material in new tires.
“We started up right from the beginning with Hägglunds drives,” Pohl says, “and we’re so happy with them that we never want to change.”
Hägglunds motors and drive systems are used at all of Genan’s sites, according to the company, which now has more than 40 hydraulic drive systems in total. Genan uses two different motors: the Hägglunds CA 100 and the Hägglunds CB 840. With high power density, the motors deliver extreme and sustainable torque from zero speed, says Pohl.
“For us, the main advantages of the Hägglunds drives are the compact and robust design, and the high torque right from the beginning,” says Pohl.
Torque, however, is not the only appeal of Hägglunds systems, says Genan. In the company’s highly automated system, the high reliability of the drives also is crucial, according to Pohl. At a typical Genan plant, there are only a handful of staff members supervising the recycling process, with just one maintenance employee per shift.
“Since we are producing 24/7, the reliability of all systems is needed at all times,” says Pohl. He praises not only the Hägglunds drive systems themselves, but also the strong support behind them. “The Hägglunds service center in Bochum, Germany, supports all our German production facilities – training our employees [and providing] short-time repairs within two weeks, and spare parts. The relationship is excellent.”
Concludes Pohl, “Hägglunds drives ensure our productivity.”
NAPA’s guidance regarding RAS concentrations in new hot mix asphalt formulations may help the use of recycled materials gain more acceptance from paving contractors.
The use of recycled asphalt shingles (RAS) in asphalt pavement has become increasingly popular among paving contractors seeking a cost-efficient alternative to virgin materials. Consisting of asphalt cement, aggregate and fiber, the composition of RAS can make it an ideal substitute for the virgin asphalt and fine aggregate routinely used in hot mix asphalt (HMA) formulations.
According to the National Asphalt Pavement Association (NAPA), asphalt mixture producers used more than 1 million tons of RAS in asphalt pavement mixtures during the 2018 construction season, and in the process, diverted about 10 percent of the total available supply of waste shingles from landfills.
While this was a 12.5 percent increase from the 980,000 tons used in 2017, it is only a fraction of the approximately 11 million tons of asphalt shingles disposed of each year.
In an effort to further the sustainable practice of utilizing RAS in asphalt mixtures, NAPA released an updated report in 2019 on the use of reclaimed shingles in asphalt pavements. The report, which was an updated version of the association’s “Guidelines for the Use of Reclaimed Asphalt Shingles in Asphalt Pavements,” laid out a number of best practices associated with RAS usage.
“I think the big thing that we just have to encourage is if you’re going to use this material, then you’ve got to do your homework,” Richard Willis, vice president for engineering, research and technology at NAPA, says. Willis was also a co-author of the report. “You have to know your material properties, such as your typical aggregate and binder, as they become even more important [when using RAS in mixtures].”
Although the composition of asphalt roofing shingles can vary depending on the manufacturer, shingle age, product line and roofing application, most contain a basic mix of asphalt binder, filler, fine aggregate or granules, and fiberglass or organic felt.
“[Practically] every asphalt mixture that we make has two of those same ingredients in it. You’ve got the asphalt binder and you’ve got some kind of fine aggregate that’s involved in the fines system,” Willis says. “When you’re looking at using the shingles in an asphalt mixture, we use them in very small dosages because your typical shingle is going to be somewhere between 20-30 percent asphalt binder depending on how old it is and what type of fiber was used with it.”
The aggregate or mineral granules on the surface of the shingles are often very durable and angular, which can be desirable for incorporation in asphalt mixtures. In addition, the surface aggregate in shingles can create added voids in mineral aggregate (VMA) in the asphalt mixture.
According to NAPA, achieving proper VMA in asphalt mixtures is a key part of meeting the volumetric properties needed to ensure a strong aggregate skeleton, the ideal amount of asphalt binder and proper air void space to provide optimal performance against cracking, permanent deformation and aging.
“When using shingles, it all comes down to ensuring these mixtures are engineered well,” says Willis.
Waste shingles used for the production of RAS are usually sourced from two major categories—post-consumer asphalt shingles (PCAS) and manufacturing waste asphalt shingles (MWAS).
MWAS, which is typically generated from manufacturers scrap, is often preferred by processors because it is free of many contaminants such as nails, wood and asbestos that might compromise PCAS composition. However, with sources of MWAS limited by geographic availability, many producers are left with only PCAS as an option.
According to NAPA, processors of RAS end up using PCAS volumes 10 times greater than that of MWAS thanks to its availability, which is usually derived from reroofing activities.
While NAPA recommends shingle recycling operations consider local, state and federal requirements when addressing contamination, the association has identified two basic modes for acceptance of PCAS.
Source separating requires the roofing contractor to deliver only clean PCAS to the recycling facility. According to the report, the shingles should be free of wood, plastics, large scrap metal, dirt, rocks, adhesives, solvents, petroleum contamination, other trash, and other substances deleterious to the shingle recycling processes.
“Most of the specifications when you look at them do have a requirement for what we would call ‘deleterious materials,’ and that’s basically our way of assessing contamination,” says Willis. “We have pretty tight specifications and requirements that states set out to ensure that these materials are clean, but it is a continual process as we figure out how to make them cleaner.”
Mixed roofing waste loads, on the other hand, require sorting the PCAS from the waste at the recycling facility. These can vary from simple “dump and pick” operations to more elaborate systems with screens, conveyor systems, and elevated picking stations to remove non-shingle materials.
To produce RAS, sorted shingles are fed into a grinder or shredder to be processed. The ground or shredded shingles then pass through a screening process where material of a specified size is stockpiled for use in asphalt pavement mixtures.
NAPA states there can be some variance with what grinders or shredders may be used to process shingles, with each manufacturer utilizing a unique combination of material-handling and size-reduction designs.
In general, the grinder will include a loading hopper, a feeding drum to move the shingles into the grinding chamber, a grinding chamber with cutting teeth, a sizing screen and an exit conveyor.
To combat the excessive heat generated during the shredding or grinding of shingles, Willis recommends adding water to the shingle material as it is fed into the grinding chamber.
“Because you’ve got very stiff material that you are grinding at very rapid speeds, one of the challenges that you see is you have a lot of heat that’s developed,” he says. “With asphalt binder, as it’s exposed to heat, it gets softer. So, to really prevent it from gumming up the system, they use the water to process and keep it cooler to help the system stay active and running smoothly.”
RAS contains stiffer asphalt binder, fibers and filler, as well as hard, durable and angular aggregates. With this is mind, several studies have illustrated the importance of accounting for recycled binder properties when incorporating RAS into an asphalt mixture design.
According to the American Association of State Highway and Transportation Officials (AASHTO) Standard Specifications and Standard Practices for using RAS in asphalt mixtures, there are three areas to address when utilizing recycled shingles: shingle aggregate gradation and specific gravity, binder quantity requirements for effective asphalt, and binder quality requirements for binder embrittlement.
Of these guidelines, some research has found that increasing the VMA requirements will increase the total and effective asphalt binder in the asphalt mixture. This is because the asphalt binder in RAS does not fully liquefy during asphalt production, leaving a portion of RAS asphalt binder that does not become effective during production.
In addition, the AASHTO MP 23-15 specification requires RAS be processed so that 100 percent passes the 3/8-inch sieve to optimize blending. Variations in processed RAS gradations have resulted in a range of RAS asphalt binder effectiveness when mixing with new asphalt binders. Generally, finer RAS gradations lead to higher effective asphalt contents.
“States and areas are starting to look at not just developing a recipe for these mixtures, but also starting to incorporate some tests that will allow people to have higher confidence that these mixtures are going to perform,” Willis says. “That may allow people to open up their specifications of their standards a little bit.”
This article originally appeared in the July/August issue of Construction & Demolition Recycling. The author is the assistant editor for Construction & Demolition Recycling magazine and can be reached at hrischar@gie.net.
Following a staff reduction that left Sonoma County, California, with one facility specialist for seven landfills, the county turned to SCS Engineers to install a cloud-based SCADA system to fill its monitoring gaps.
In April 2015, Sonoma County, California, divested all active disposal operations within its jurisdiction, reducing its staff from over 50 active employees down to three.
Left with only one facility specialist for seven landfill sites located hours apart, the county’s Public Works and Integrated Waste Division was left with a dilemma on how to manage its landfill monitoring workload with fewer employees.
“Federal and state regulations require post-closure maintenance, monitoring and reporting for closed landfill sites in order to safeguard the health and welfare of the public and to protect the environment,” says Glen Morelli, a geologist for Sonoma County’s Department of Transportation and Public Works Integrated Waste Division. “With limited staffing, it was desirable to automate, where applicable, these functions to more efficiently manage these legacy sites.”
With Sonoma still responsible for maintaining the closed landfill sites, the county released a request for proposals in October 2015 to identify a supervisory control and data acquisition (SCADA) system that would capacitate monitoring at five of Sonoma’s sites to mitigate the county’s staffing dearth.
Ultimately, SCS Engineers was up to the challenge, offering a cloud-based SCADA system. Based on a comprehensive proposal and discussion with SCS’ technical staff, the county chose to partner with the Long Beach, California-based environmental consulting and construction firm on the implementation of a Remote Monitoring Control (RMC) system.
The proposed system would integrate the landfills’ electronic monitoring systems via the internet to help track their data. “The amount of work that 50 people can do is not the same amount of work that two or three people can do. So, [Sonoma County] needed some way to bridge that gap,” says David Hostetter, regional manager for SCS Remote Monitoring and Controls (RMC).
Through a network of sensors and machine-to-machine (M2M) applications, the system provides facility teams with a single secure application for their SCADA, data management and reporting needs.
“An [RMC] system allows you to keep track of the separate sensors and controls all in one packaged control data acquisition and viewing application,” says Hostetter. “These systems are set up so that owners and operators of landfills can monitor the entire facility from their mobile phone or their computer.”
He adds, “The key to the system is the internet connection. There is a series of control panels and sensors that are connected, generally through some sort of wireless network. The data is collected at that location and then sent out over the internet back to a server, where clients can look at their facility remotely.”
“The primary goal of our SCADA system was to have information readily available anytime and anywhere [away] from our sites, [so there was] specific data we wanted included,” says Morelli. With this in mind, SCS enabled several functions to support Sonoma’s RMC, including alarms, data recording and review, radio systems, an industrial cellular modem and weather stations.
Sonoma, in particular, requested the monitoring of weather patterns, leachate storage volume, power and backup, and flare operations. In order to obtain this information, SCS installed sensors on each piece of equipment the county wanted to monitor. The sensors were then configured to specified parameters based on the sites’ unique needs and environmental reporting responsibilities.
A dashboard interface allows the facilities to review data from each site individually or collectively. To enable this, SCS records the data on each site and streams it to a cloud database with the MQ Telemetry Transport or Message Queue Telemetry Transport (MQTT) ISO standard.
For its leachate storage monitoring, the county utilizes an application provided to its contracted haulers that allows drivers to see on their phone when a facility needs leachate hauled to storage. Similarly, mag meters on pump stations allow the team to see when a waste hauler arrives at a site and how much leachate is removed from the facility.
“By being able to monitor leachate generation and off-haul, we can more effectively manage our hauling contractor, which brings leachate to the wastewater treatment plant from our facilities,” says Morelli.
Noting that leachate generation can be heavily influenced by rainfall, SCS also installed a weather station with an ultrasonic anemometer at each side of the sites. This allows the firm to track rain accumulation, temperature, humidity, wind speed and wind direction, while also providing the ability to control the pumping systems based on current and predicted rainfall.
When the sites’ sensor readings are detected outside an acceptable range, or if an environmental threshold is reaching exceedance, the RMC is designed to send an alert to appropriate staff through a phone, computer or tablet.
The county’s alerts feature a customized combination of email, voice and SMS alarms that are sent to various liquid haulers and end users, which are delivered through a central internet-based cloud gateway that supports all five sites. SCS can also reduce the amount of hardware necessary on-site, and the county can remotely adjust alarms and create new alarms as operations and compliance dictates. These notifications are critical in Sonoma County, where a number of sites are subject to power outages, which can heavily impact remedial facilities on-site, so the system lets personnel know if power is lost, as well as if the backup generator takes over.
“Having the virtual check on system operations allows us to not have to send a technician or facility specialist to the site if we can see the system is functioning property during a power outage,” says Morelli. “This has become a more important feature given the planned power outages implemented by power providers in [California] over the last few years.”
According to Hostetter, the ability to manage a site remotely has been a major benefit to clients, including Sonoma, during the COVID-19 pandemic.
“Sitting here at my desk in Pennsylvania, I could look at a site that’s in California,” he says. “[Remote monitoring] lowers the operations and maintenance costs because the owners no longer have to pay for somebody to physically go out to the facility, so it’s cutting out all the drive time and lowering their health and safety obligations, as well.”
For Sonoma County, the biggest economic advantage of the RMC system has been in hauling cost savings. “Before the system, we would send out tanker trucks to a facility to remove leachate from storage, not knowing if there was a need or not,” Morelli explains. Many times, he adds, this resulted in half-full or near-empty loads where the county deployed a resource and did not need it. With the RMC in place, Sonoma can now track if the need is there before deploying a resource, whether that is to remove leachate, fix a flare or deal with a power outage.
Currently, SCS has installed RMC systems at roughly 100 sites across the U.S.
“We’ve found [this system] as an overall organization to be really beneficial for our engineers and our field staff,” says Hostetter. “We want to try to leverage technology as much as possible to enable our field staff to be able to get more done, our engineers to understand the systems better, and really we want to try to make everyone’s life better.”
This article originally appeared in the May/June issue of Waste Today. The author is the assistant editor of Waste Today and can be reached at hrischar@gie.net.
The funding will be used to implement or improve waste reduction, reuse, recycling and composting activities.
In pursuit of its mission to improve Franklin County’s solid waste stream, the Solid Waste Authority of Central Ohio (SWACO) has awarded $201,873 in competitive grant funding to 15 community projects to implement or improve waste reduction, reuse, recycling and composting activities.
The projects include installing refillable water bottle stations in central Ohio’s largest school district, putting recycling sorting stations in facilities that serve the public, supporting permanent community drop-off locations for food waste, and enhancing an app that connects organizations that have available food with organizations that need it.
“Interestingly, more than half of the projects this year aim to reduce residential or commercially generated food waste,” said Ty Marsh, executive director at SWACO, in a release. “This is a change from previous years and reflects our community’s growing interest in and commitment to reducing food waste.”
The announcement of SWACO’s grant awards follows information released earlier this year documenting that food waste is the top item, by weight, thrown away in Franklin County and presents one of the biggest opportunities to divert more waste from the landfill.
In addition to SWACO’s financial award, the grant program leverages an additional $127,265 in matching funds from grantees for a total investment of more than $329,000 by the community toward waste composting, recycling and waste reduction projects.
The 2020 Community Waste Reduction Grant recipients include:
Food Waste Reduction and Composting Projects
Waste Reduction and/or Reuse Projects
The 345-acre site has been identified as a Superfund site since 1986, but the EPA determined in May that the landfill no longer needed to be listed as a location posing a risk to human health or the environment.
The U.S. Environmental Protection Agency is seeking public comment on plans to remove the Northside Landfill in Spokane, Washington, from Superfund status.
As reported by The Spokesman-Review, the 345-acre site has been identified as a Superfund site since 1986, following the discovery of contaminants that included an industrial degreaser and dry-cleaning chemicals in the groundwater beneath the landfill.
Piles of buried trash taken to the site since 1931 had been buried in unlined pits, a practice that ended in 1991. Since then, the EPA has monitored groundwater from test wells located to the northwest of the site and determined in May that the landfill no longer needed to be listed as a location posing a risk to human health or the environment.
“While groundwater meets federal drinking water standards and treatment is no longer needed, groundwater monitoring will continue,” an EPA statement released July 14 said of the Northside Landfill site. “As an active landfill, the site will continue to be regulated by state and county agencies.”
The EPA tracks 1,335 sites as national priorities for cleanup. The agency is proposing removal of three Washington locations from the list, including the Northside Landfill, a former lumber treatment facility in Chehalis and the soil at a formal hazardous materials disposal site near Maple Valley.
Environmental regulators will be accepting written comment on the proposal to delete the landfill from its list of priority Superfund sites through Aug. 13.