By Ben Messenger
As it rolls out its single stream recycling collection program to an increasing number of residents in Clark County, Nevada, Republic Services' existing 88,000 square foot (8175 square metre) Materials Recycling Facility (MRF) is nearing capacity.
To meet the growing volumes of recyclable material being collected thanks to the increased participation of residents in the new program, the company has begun work on a new 110,000 square foot (10,200 square metre) facility on an adjacent site. The equipment for the new facility is designed and being built by CP Groupof San Diego, California.
"Why we're heading this direction is that in the past we collected recyclables with a three bin system, which was a little bit more difficult, and we didn't have the participation that we do now," Bob Coyle, Republic Services' vice president of government affairs for Southern Nevada tells WMW.
"We've changed to an all in one program where we're putting out 95 gallon (360 litre) carts. Through that we've seen participation increase and volumes increase significantly. That's pushed us into needing to increase capacity to handle the increased volume. Currently we're pretty much at capacity at the facility that we have today, so that's what moved us into building the new facility."
The new facility, claimed to be the largest single stream recycling facility in the world, will have the capability to process 265,000 tons (240,000 tonnes) on an annual basis – roughly 70 tons (63.5 tonnes) per hour throughput.The rollout
Coyle explains that Republic has exclusive residential and commercial contracts with unincorporated Clark County, which has about 210,000 homes. In addition to the unincorporated area there are 160,000 homes with the City of Las Vegas, 65,000 homes with the City of North Las Vegas and 85,000 homes with the City of Henderson.Once operational the MRF is expected to be the largest single stream recycling facility in the world
Currently the City of North Las Vegas and the City of Henderson have authorised Republic to implement the new all in one cart program and those have been fully converted.
In the unincorporated County the company currently has around 10,000 homes on pilot programs, but in November 2013 the County voted to convert the entire unincorporated area to the program. In the City of Las Vegas it has around 15,000 homes on pilot programs and the City is moving forward to approve converting to the program but the final vote has not taken place as yet.
In total there are currently around 170,000 homes that are on the program. As a result of the increase in participation, the recycling rate in those areas has gone from about 3% of the waste stream at the kerb to about 30%. Those significantly increased volumes of recyclable material are currently being processed at the existing MRF on the company's Southern Nevada Recycling Complex.
"Back in 1991 when the facility was built technology was really very rudimentary," explains Len Christopher, general manager of the Republic Services' Recycling Division.
"Five or six years ago we made changes to do a better job of sorting with optical sorters and eddy currents and screen packages and things like that," he continues. "But the current line is capable of processing 25 tons per hour and we just really don't have the capacity, so the new facility will be a game changer for us. It'll allow us to process much more efficiently because technology changes every three or four years in this business. It'll allow us to obviously increase throughput, but also to increase recovery."Long-term benefits
Republic currently has long-term contracts to manage residential waste in Clark County. Two of its contracts don't expire until 2035, another runs to 2031 and a fourth 2021.
"The ability to spend $35 million on a new recycling facility is enabled by the fact that we have these long term stable contracts," says Coyle. "If you have a five year contract it's pretty hard to justify the investment. By having the long-term contracts we're able to do it while having stable rates. Our rates in Clark County are among the lowest in the U.S. and by far the lowest in the south west U.S.," he continues.The facility will feature numeroud MSS CIRRUS™ optical sorters to ensure maximum recovery of recyclable materials
"When you have those long-term contracts you need to provide the service that your customers want, and our customers were telling their elected officials that they wanted a better recycling program. As elected officials usually do, they listened to their constituents and that's why they asked us to move forward with our recycling program," he adds.The CPScreen automatically separates small fibres from containers, and 2D from 3D material
When a community goes on the program residents receive a recycling cart and a welcome kit that goes through the details of the program and what type of materials can be recycled. Embedded in the blue lid of the recycling cart are pictures and descriptions of all the things that can be recycled.
Under the old system the company provided waste collection twice per week and a fortnightly collection of recyclables, both from 12 gallon (45 litre) crates. To keep the rates low, under the new system Republic moved to once per week waste collection and once per week recycling collection using 95 gallon (360 litre) carts and two separate collections.
According to Coyle, while some residents are initially unsure about the reduced frequency of waste collections, once they're on the program they find that the extra capacity more than compensates. "The feedback we get is, ‘I didn't realise how much I could recycle'," he says.
Once operational the company intends to use a purpose built Education Center at the new MRF to reinforce its drive to educate residents on recycling.
"One of the nice things about the Education Center is that it'll run the length of the building so we can host school tours as well as other private tours so that anyone that wants to see the facility can come in and be able to see what we're doing without being put in a dangerous situation," explains Coyle. "One of the big things we're looking forward to is the ability to provide more school education, because when you get kids interested in recycling they go home and beat up mom and dad about not putting newspaper in the trash."Building BIG
With the pressing need to increase its recycling capacity, following a request for proposals Republic Services brought three key partners on-board: architects EV&A; design and construction firm Cambridge Construction and recycling equipment manufacturer, CP Group.
Having joined the project partners two years ago, Cambridge Construction - which has worked previously with CP Group and Republic Services on a MRF in Oberlin, Ohio – was responsible for designing and constructing the facility's building. It broke ground on the project in November 2014 and expects it to be complete and operational by autumn this year.
The sorting and processing equipment at the heart of the new facility is to be supplied, installed and commissioned by the CP Group, a part of San Diego, California based CP Global.
"One of the things about Vegas that we knew from the stream that we already have - is that it's a pretty dirty stream", Terry Schneider, CP Global's CEO tells WMW. "Their current residue is about 18% or 20%. Looking at the characterisation of that residue stream we believe that we can get that down to closer to 15% because we'll clean more of the recyclables."
"To achieve the end result we needed to come up with a system that could do 70 tons per hour. That's going to be the world's largest single stream system," he continues. "I know of a lot of 50 and even some 60 ton per hour single stream systems, but at 70 tons I don't know of anything that's larger than that worldwide."Design of the line
To meet the challenge, CP Group based the MRF on two infeeds both processing 35 tons per hour. Two lines separate the paper and containers, but these are merged into a single line once the sorting process has reduced the stream to 3D containers.
The plant features metering drums at the beginning of each of the lines, which both have a pre-sort. From here the material moves on to an Old Corrugated Containers (OCC) screen followed by two Scalping Screen which removes some of the fibre and allows the containers to go directly to the CPScreen™. The resulting fibre from the Scalping Screens goes to four NEWScreens to separate the newspaper. The final process for separating 2D and 3D is the patented CPScreen™.The CP NEWScreen separate larger fibre from mixed paper, containers, dirt and debris
All of the materials that are considered 3D fall backwards off the CPScreen. These go to two MSS CIRRUS™ optical units that will fire high pressure air jets on everything that is a recyclable. From there the 3D material passes a magnet, which removes all of the ferrous metals.
Continuing its journey through the process the remaining material goes to another scalping screen that takes all of the 5 inch (13cm) and below material. This separates the aluminium cans and PET bottles, which tend to be smaller, from the HDPE containers that are generally larger.
The smaller of those two fractions is sent to an eddy current, which separates out the aluminium cans from the PET. The PET is then mixed back in with the HDPE for processing by a further three separate MSS CIRRUS optical sorters that separate the PET from the HDPE and also sort both polymers by colour. Because the materials pass through so many high-tech processes, controlling the equipment in the recycling line so that it all works together is critical. To this end, Schneider explains that the MRF will be equipped with the company's Supervisory Control and Data Acquisition (SCADA) control package to provide operators with seamless, plant-wide optimisation and data acquisition tools. The system offers touchscreen handheld controls.Looking forward
Once the new plant is online, Coyle, Christopher and Schneider all expect to see the amount of residual waste being sent to landfill from the recycling stream to fall, and the percentage of material being recycled in Clark County to increase.
While the State of Nevada established a 25% Recycling Goal in 1990, there is no mandatory target. In contrast to some countries, and other U.S. states, the drive to increase recycling in Clark County has not been driven by landfill taxes or prospective fines, but by ground level public opinion that it would be the right thing to do.
The voters told their elected officials they wanted better recycling, and the elected officials asked their contractor to make it happen. The result? A huge new recycling facility that will allow the roll out of the new collection service to continue increasing the recycling rate.
They say that Vegas was built on losers, but when it comes to increasing its recycling rate, it's a safe bet that when this facility comes on-stream, Clark County will be onto a winner.
Ben Messenger is managing editor of Waste Management WorldTaking Control
CP Group's iMRF™ (intelligent MRF) SCADA system was first deployed at Republic Services' Lorain County Resource Recovery Complex in northeast Ohio, which features the company's latest mechanical and optical units.
"The electrical control is seamless from the infeed conveyor to the baling stage, and includes belt scale, WI-FI touch screen, cameras and complete SCADA software with Office Interface System (OIS) station," explains Patrick Nicol, CP Group sales engineer.
The OIS tracks all event logs with a time stamp, and production metrics such as tons per hour, bale weights, residual percentages, system power requirements, as well as uptime and downtime, along with the reason for any downtime.
The real-time data and system feedback enables operators to respond quickly to any events within the MRF.
The SCADA/OIS software at the facility was custom developed through collaboration between Advanced MRF, the division of the CP Group which integrated the control package, and Republic Services for system optimisation and data acquisition.More Waste Management World Articles
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