Solid Waste & Recycling

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MRFology 101

In its 2007 Strategy to Increase Diversion of Plastics from Ontario Households , the Environment and Plastics Industry Council (EPIC) identified a number of issues affecting the recovery of plastics a...


In its 2007 Strategy to Increase Diversion of Plastics from Ontario Households, the Environment and Plastics Industry Council (EPIC) identified a number of issues affecting the recovery of plastics and the need to establish best practices to support higher plastic recovery rates. In order to further this strategy, and to better determine some of the challenges being faced by material recovery facility — or what we prefer to call municipal recycling facilities — (MRFs), EPIC conducted preliminary research at waste management facilities located in southern Ontario. The facilities handled an expanded stream of materials that included old newspapers (ONP), old corrugated containers (OCC), old boxboard, steel cans, aluminum cans, glass bottles, plastic PET and HDPE bottles, polystyrene foam, plastic film and bags, and plastic tubs and lids.

Information gathered from tours of the facilities, along with input from consultants, extensive discussions with municipal staff, industry experts and equipment vendors, led to EPIC being able to extrapolate some key findings and to develop a list of recommendations that could be adopted by MRFs all across the country in order to better the efficiencies of their operations and to address future design issues. This list was later used to propose benchmarks and recommendations for the design and procurement of a greenfield MRF.

Although much of the research for this project was based on MRFs and staff located within southern Ontario, many of the design recommendations and findings can easily be used by other MRFs across the country that are interested in improving their internal efficiencies.

Key findings

One of the first key findings in this project was the understanding that the issue of increasing plastics recovery was not a plastics-only issue, but rather an issue linked to the broader system (contracts, promotion and education, collection, processing and markets) affecting all recyclable materials and the quality of these materials marketed from MRFs. Although there is significant investment in MRF processing capacity within the province of Ontario, this capacity is not adequately set up to handle an expanded stream of plastic packaging, nor other containers and paper fibres that are typically collected in single-stream systems. On the contrary, MRF design, procurement, investment, equipment and operations are primarily focused on handling paper fibre, which represents 65 to 70 per cent of the tonnage entering Ontario MRFs.

Contract prerequisites

A number of specific details related to contracts should be taken into consideration by MRF operators when either entering into a new contract or renewing an existing one. The first factor is the term of the contract itself. If the MRF is privately owned and built to service a specific municipality, the term of the contract should be for at least 10 to 15 years in order to provide adequately for equipment amortization. This length of contract allows for greater flexibility and design choices, especially where choices of capital versus labor becomes a key design criteria.

If a municipality is interested in a design and build project, it should consider issuing a Request for Proposal (RFP) as opposed to a Request for Quotation (RFQ). The RFP approach allows greater input from the equipment supplier, based on the municipality providing detailed audits of the types, sizes of containers and estimated quantities of commodities to be processed, as well as unwanted materials appearing in the MRF. Complete information on expected curbside collected materials and possible additions and changes over the life of the contract translate into more accurate responses by bidders and MRF designers. Additionally, the municipality’s decision should be one based on life-cycle costing (which includes all capital and operating costs over the life of the contract) as opposed to just the cost of capital equipment.

Another recommendation is for the municipality to ensure that the contract has performance standards built in, with penalties and remedies for contractors not meeting performance statements made in contractor RFP submissions.

Feed systems

Many municipalities allow householders to use plastic bags to contain additional recyclables as an overflow mechanism for blue boxes and carts. MRFs require the ability to debag and, to do so effectively, the municipality should specify that householders use a standard size of bag suitable for debagging. This standard-sized bag should meet the specifications of the manufacturer of the bag breaker. The use of non-standard bags (e.g., grocery sacs) greatly increases the costs of processing and inhibits debagging operations.

Additionally, operators of facilities should consider removing the opened bags at the bag breaking machine, rather than removing them manually further upstream. This will improve efficiency and speed up the sorting process.

Pre-sort

One of the critical areas of a MRF that needs specific attention is the pre-sort area. This is where materials are conditioned before being fed into the main processing area. Pre-sort areas can be considered a key quality control area and, as such, must exist in all MRFs (single or multi-stream) in order to deal with unwanted materials and the effective recovery of materials.

The pre-sort area needs to be of sufficient size to condition materials for effective sortation downstream. It is here that items (PS foam, film plastic, oversized items, unwanteds and bulkies) are quickly removed. Sufficient staff are needed to man this area. Staffing will depend on the MRF’s designed throughput, expected tonnages and types of materials expected that were outlined in the RFP to the MRF designers.

It’s important that conveyor speeds and metering of materials be appropriate for effective removal of material. Any materials not conducive to screening (film, foam PS, large container, pails, unwanted items) need to be removed as early as possible in the pre-sort area. To operate effectively, MRFs require the appropriate number of bunkers to handle the removed materials. Municipalities should also consider the use of pre-sort vacuum extraction systems for removing film, as well as removing tied bags of bags.

Separation systems

OCC screens: The use of OCC screens to separate large OCC from ONP and containers is an important step in material sorting. Municipalities should ask for the separation capability of the screens. Additionally, eliminating any bundling of OCC in collection (e.g., rope, tape) would allow for more effective sorting.

A secondary pre-sort should also be used before the ONP screens in order to remove any remaining OCC, film, plastics and other unwanted materials (e.g. telephone books).

ONP separation from containers: The effectiveness of separating containers from paper at both the primary and secondary ONP screens needs to be evaluated against the use of other systems. Not all equipment is created equal. Adjusting screen angles and discs may not be the solution.

ONP quality control: EPIC’s research found that the use of improved pre-sort areas, combined with capital investment in effective screens with pre-sort film extraction capabilities, reduced the amount of labour needed to efficiently sort the materials. An effective ratio of quality control labor to throughput was found to be around three tonnes per hour per sorter.

Container/fibre separation: If all of the aforementioned steps have been taken, then the final separation of fibres and containers should be able to be completed mechanically with minimum labor.

Fibre stream quality control: Optimum fibre stream quality control was found to be around five tonnes per sorter per hour. The use of effective container and fibre sort screens can replace the need for manual sorters to remove any fibre prior to th

e containers entering the container sort room.

Container stream quality check: Effective container and fibre sort screens would be able to reduce/eliminate these sorters.

Steel and glass sortation: The industry standard to remove steel and glass containers is the use of an overhead magnet (for steel cans) and a trommel (to remove glass).

Container sort area: Previous EPIC research has found that automated optical sorting of plastics is justified in those MRFs where there are two or more sorters who manually sort a commodity. The use of automated sorting equipment would require that aluminum be sorted prior to this stage. Additionally, any contamination (such as dirt and dust) must be kept to a minimum. The optical sorting equipment would be set to deal with the largest volume of containers in sequence.

Two different optical sorting options are possible. The first is the use of a double valve block to sort PET into the first two bunkers, plus the use of one sorter for quality control. HDPE can be the second material, with a manual sort for natural if it turns out to be economically viable. Again, one sorter for quality control would be required.

The second option is to sort PET and HDPE containers separately, which results in a 10 per cent higher capture rate than a double valve block.

The MRF operator needs to determine the cost benefits of the two different options and to investigate the use of optical sorting technology for any volume group left in the container line (e.g., tubs and lids, PS rigid, polycoat/aseptic). Another avenue of research is to investigate the use of EDDY current operations and adjustments for aluminum, which could improve recovery rates to at least 95 per cent. If such action is taken, the EDDY current needs to be positioned before the optical sorter so the aluminum will not be confused with PET.

In the case of one of the MRFs visited by EPIC for the purposes of this study, the design recommendations — if adopted — would result in significant economic benefits. The use of optical sorting equipment alone would have resulted in a 90 per cent recovery rate for PET, with a corresponding $51,000 increase in revenue. Similarly, optical sorting equipment would have resulted in an 85 per cent recovery rate for HDPE, equal to a $192,000 increase in revenue. Add to this the labor savings inherent in the PET and HDPE sorting operations. Depending on retrofit costs, payback on the optical sorting equipment was estimated to be between two and five years.

Market tips

EPIC found that the type of long-term contracts currently in place for fibre markets should be encouraged for plastics and other types of packaging. These contracts reduce the risk to both parties (sellers and buyers) and ensure that there is a mechanism for addressing market fluctuations. MRFs should also attempt to support North American markets for their products and to help create long-term market stability. Lack of support for local markets could lead to the closure of processing capability in North America (specifically plastics). Reliance on off-shore markets isn’t necessarily beneficial going forward.

Cathy Cirko is the Director General of the Environment and Plastics Industry Council (EPIC) www.plastics.ca/epic, a Standing Committee of the Canadian Plastics Industry Association (CPIA). Contact Cathy at ccirko@cpia.ca

At a Glance

The following is a short list of findings and suggested modifications to sample MRFs visited by EPIC and its team.

1. There are falling recovery rates for all materials except fibres in the attempt to meet facility throughput requirements in contracts to avoid penalties.

2. Citizens should be required to use a standard sized recycling bag for additional recycling capacity that will meet bag breaker requirements and specifications (no smaller bags).

3. Evaluate equipment to remove bags at the same time of bag breaking to eliminate manual removal at the pre-sort.

4. Do not open small bags containing film plastic only (i.e., bag/film recycling).

5. Presort area conveyor is moving too fast to allow for more effective removal of film and other materials. Improvement in this area will improve quality of downstream sorting and market quality of ONP and fibres (but will affect throughput).

6. Investigate alternative ONP and container/fibre separation screens and screen angles. More effective screens will reduce quality control labor component.

7. Improve vacuum system from glass line to reduce impact on ONP quality line.

8. Consider replacing trom-mag with overhead magnet to capture cleaner ferrous.

9. Investigate Optic Sort Options for container line — estimated payback can range from two to five years. Options are:

* Optic sort — double valve to sort PET and HDPE

* Optic sort — single valve for PET only

10. EDDY current operations require investigation as revenue losses estimated to be in the $200,000 range with an additional cost of quality control (one person).

The Top Ten Reasons People Don’t Recycle

1. Laziness: What day is recycling again? Is it this week or next? I’ll do it next time.

2. Lack of Regulation: There is no peer pressure or accountability from the local government or haulers. Local government is complacent and doesn’t initiate the change. Nobody is making me, so why do it?

3. It’s Not Convenient: I wake up and buy a coffee. No recycling there. I go to work, no recycling there. Then I take my kids to a ball game, the mall, out for ice cream. No recycling to be found. Why should I do it at home?

4. Urban /Suburban myth: It all gets trashed anyway and ends up in the same place. Why should I bother?

5. Cost: Recycling costs more than trash pick-up. Why should I have to pay?

6. It’s Too Much of a Hassle: I don’t have the time to separate recyclables into different bins. I don’t have the space. It’s dirty. Trash is out of sight, out of mind.

7. Ignorance: It’s just like voting…does my one vote really make a difference? Will my little bag of recyclables make a difference in the world?

8. Poor Recycling Education: I don’t know what to recycle or where to recycle it.

9. No Available Recycling Program: There is no recycling available in my town

10. What’s in it for Me: What am I going to get out of recycling? Recycling just doesn’t pay off for me.

RecycleBank is a U.S-based rewards program that started in the upper Northeast and is being expanded across the country. It motivates people to recycle by rewarding households for their recycling efforts. It does this by quickly and easily measuring the amount of material each home recycles and then converting that activity into RecycleBank Reward Points that can be used at hundreds of local and national retail partners like Starbucks, Target and Coca-Cola, as well as local retailers like grocery stores. RecycleBank is simple to implement, market-driven and proven to work, saving municipalities’ money and rewarding citizens for their environmental stewardship.

RecycleBank makes it easy to implement the program because of its use of rewards based recycling and single-stream recycling. The more a household recycles the more rewards the household receives. The program uses single-stream recycling to help drive recycling efforts. Single-stream recycling allows all recyclables (cardboard, paper, aluminum, tin, glass and plastic) to be placed in one container, as opposed to other methods which required recyclables to be separated.

RecycleBank is market-driven because it saves money — and makes money for its participants. By implementing the RecycleBank program, city planners are looking to encourage citizens to increase recycling efforts, which RecycleBank is proven to do. By improving recycling rates, municipalities are spending less mone

y on tipping fees at local landfills, thus saving the municipality money that would otherwise be spent on landfill fees. This money can then be used for other public initiatives such as education or urban renewal.

RecycleBank also provides companies the opportunity to become a Reward Partner. RecycleBank Reward Partners recognize the vast marketing opportunities in connecting themselves with a program that promotes recycling, community involvement and environmental sustainability. When households log in to the RecycleBank Web site to redeem their RecycleBank Points, they can readily view reward partner’s logos and links to respective Web sites. The more households recycle, the more money they have to spend at local and national participating rewards partners.

Visitwww.recyclebank.com


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