Scientiﬁc Chronicles Magazine - · PDF filedistinction between orange peel and a cardboard box, but, it is more difficult to differentiate between recyclable and non-recyclable plastic

2 InterviewDirector of the Waste Collection, Sorting and Recovery Research Program

6 Research Program DAD: A Remote Selection Tool to Allow Sorting Operators to Work from an Office

TSA2: Project Timeline

8 MethodPeople Are More Important than Machines

9 Technologies A Decision-aid Tool for Sorting Paper and Cardboard

Three questions for… Olivier Scalliet, Manager of the Châteaubernard Sorting Center

Today, 15% of the waste treated by Veolia Environmental Services is recycled. The Company has set itself the goal of doubling recovery rate by 2012.In order to industrialize recovery facilities, it is necessary to optimize the recovery of materials and improve waste separation at the source. This is a challenge on both a technological and human level for researchers at Veolia Environnement. Here is a closer look at the progress made in sorting household waste from source-separated collection (papers and packaging).

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Issue 16 / How to Optimize Waste Sorting / September 2009 Research Innovation

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Veolia Environmental Services aims to

double the rate of recovery from the waste

it treats. Why has this target been set?

“To avoid wasting resources! Materials are too precious to be thrown away. Waste recycling is as import ant for the environment as it is for the economy. This explains why it is given priority status in European and national waste policy guidelines. According to the Waste Framework Directive 2008, European Union Member States must recycle 50% of their household waste by 2020. The French Environmental Forum Grenelle 1 set an organic and other matter recycling rate of 35% for 2012, and 45% for 2015. Waste contains a range of material (paper, cardboard, metal, glass,

plastic, etc.) which, if treated properly, can be recycled and reused in a manufacturing production cycle. Through recycling the quantity of final waste is reduced as is the associated environmental impact. In addition to saving virgin raw materials, recycling generally saves energy and water and lowers greenhouse gas emissions. It also limits the environmental damage caused by mining or the over-exploitation of forestry resources. Today, the recession has somewhat relieved tensions on international raw material markets. But for how long? We live in a finite world. Population growth and the economic

development of emerging countries are putting even greater pressure on natural resources. At the same time, waste from human activity is building up. It is essential that as much material as possible be extracted from

waste to alleviate pressure on our rare resources and to protect the planet’s equilibrium. Recycling is based on the principle that “nothing is lost, nothing is created, everything is transformed,” attributed to Lavoisier. It describes the specific cycle of naturally regulating mechanisms and is one of the forms of industrial ecology.”

How does Veolia Environnement Research &

Innovation contribute to achieving the target

rate of 30% recycling?

“In addition to the qualitative improvement of source separation by households, our aim is to optimize and develop the sorting processes used by Veolia. Sorting is a strategic step in waste recycling, so better quality sorting leads to increased recovery levels. Our aim is not just to increase the quantity and types of material recovered from waste, but also to improve workplace health and safety (or working conditions). For us, the dual objectives of technological progress and improved working conditions for operators are inseparable, as sorting

INTERVIEW

Olivier Doyen“Materials are too precious to be thrown away.”

“ Nothing is lost, nothing is created,

everything is transformed”

Lavoisier

Olivier Doyen,

Director of the

Waste Collection,

Sorting and Recovery

Research Program

[email protected]

Issue 16 / How to Optimize Waste Sorting / September 2009 Research & Innovation



is today largely a manual operation. Therefore, our focus is on automating waste sorting centers using increasingly sophisticated technology. Specialists in ergonomics, psycho-sociology and sociology are involved in our research projects, to help assess the impact of changes to working conditions, and so predict the skills that will be needed to use the technology we are developing.”

How will automation benefit operators?

“One of our research programs is looking at eradicating all contact between the sorter and the waste. We are developing a remote sorting tool (called DAD), which is currently in the laboratory pilot stage and should be operational in 2010 (see pages 6 and 7). It works using a camera which projects an image of the sorting belt onto a touch screen. The operator selects an object and in doing so triggers its ejection.”

What solutions have you come up with to in-

crease throughput and the range of material

recovered?

“In 2006, we filed a patent for a so-called auto-adaptive sequential sorting system (TSA2), which uses sorting machines at manufacturers’ guaranteed maximum pass rates and which is currently used for sorting hollow items made from a variety of materials: HDPE (milk bottles), clear and colored PET (soda bottles), polystyrene, polypropylene and food

cartons.”What does auto-adaptive sequential sorting

mean?

“Usually, a sorting machine is set to eject a certain material (two types at the most). With the computer system we have developed, the machine can be programmed to extract several types of material (up to around ten), one after the other–in several sequences–from the same sorting belt. Our system is designed to constantly adapt t h e e j e c t i o n orders to the composition of the waste flow, hence the term ‘auto-adaptive.’ The system designates a material to be ejected for a given lapse of time, the others continue to rotate in a loop on the chain, like suitcases on an airport carousel, and are ejected in the following cycles.”

What are the advantages of TSA2?

“There are many. First, we are able to significantly speed up through rates. The ejection of materials by order of quantitative priority frees up room on the sorting line and means we can in feed waste continuously without saturating the process. TSA2 also has the advantage of using just one machine to do the same job that it used to take five machines to do. This means savings in machine

“ Our focus is on automating waste sorting centers using

increasingly sophisticated technology.”



investment and space. Our system also provides more detailed sorting and so the recovery of a greater quantity of used material. This is essential for the development of new recovery applications that need to be competitive relative to the process that produces these materials. Automating sorting also boosts the economic feasibility of recycling.”

What will happen to the Sorting Operators?

“They will be up skilled to provide quality control for the machine sorting as a sorting machine is only about 90% effective, and human input is still needed to correct errors. This presupposes a major shift in the operators’ work. Until now, manual sorting was organized into a series of tasks performed at separate

workstations. Sorting Agents change workstation two to three times a day. The quality control operator will have to adapt to the machine cycle changes. TSA2 will mean a major change in work rates. In a standard automated sorting configuration, the operator working on the flow ejected by the machine must also correct any errors, but only for one type of material. With TSA2, we will break with this monotony and the operator will work on several types of material a day. However, we have noted that the quality control operators working on optical sorting machines had peak periods of activity with high flow rates. One of the reasons for developing the DAD tool is precisely to avoid this laboriousness. The principle is to focus operators on their observation expertise and to free

them from having to physically grab objects. With this process, it is possible to designate more objects than you are physically able to grab. We are making every effort to ensure that the man-machine pairing works in the best possible way. In terms of the ergonomics, work organization and training (See page…). »

What will the impact be on job numbers?

“We have performed simulations to identify the changes to employment resulting from automated sorting. The switch from manual to automated sorting does not actually mean fewer jobs. Jobs will be created and some operators will have the opportunity to change positions. This is because, as you

automate the sorting process, you gain access to greater quantities of recyclable materials that are currently not sorted, and the greater the quantity of secondary materials you generate, the more human resources you need to monitor the quality of the throughput. Recovering a metric ton of waste plastic will require more labor than producing the same amount of plastic directly from oil. This means the job outlook is positive in the long term.”

What types of systems are used to achieve

extremely precise automatic material

sorting?

“The system is based on software that determines the order of ejection and an optical sorting machine. In practice, you press a button and you eject those made from a specific material (e.g. clear



PET) from among the flow of hollow containers (plastic bottles, food cartons, etc.). One of the problems we had to solve was how to integrate the large volume of data from the sor ting machine with the systems i n s t a l l e d i n s o r t i n g centers. When should you eject the product that forms the bulk of the material on the line? From what volume difference compared with the other materials? We developed an algorithm to define the rules and settings and answer these questions. A research pilot was then installed at our prototype research unit near Lyon (France) to demonstrate the system’s feasibility.”

Could the sophistication of sorting machines

mean households no longer have to sort

their waste?

“The very precise capacity for elective material recovery has raised the question of whether household waste collection methods need to change. Considering the sorting of dry waste (plastic, paper, cardboard and metal) can now be industrialized, would it be more socially, economically and environmentally viable to ask households to focus their sorting just on food and hazardous waste, and to put all the rest together in a single bin? Or to initially extend the number of types of material to be placed in the recyclable waste bin? We are studying the impact of this kind of “cultural revolution” in terms of the simplicity of sorting behavior, the number of collection rounds, and improving the recovery of bio waste and material. Anyone can make the distinction between orange peel and a cardboard box, but, it is more difficult to differentiate between recyclable and non-recyclable plastic whereas a machine can make that distinction. If sorting is made simpler for households, we can expect that the quantity of sorted material will increase.”

Are there outlets for all the different types

of material that can be recovered by sorting

machines?

“At present, not all materials can be re-covered. Often the recovery application does not exist because the quantity of material recovered is insufficient. But for many plastics in the average house-

hold bin, there are recovery applications. For example, they exist for polystyrene, used for yoghurt pots, or polypropylene, used for food trays. Even if some plastics

are non-re-cyclable for technological, economic, or environmental reasons, their

energy recovery is still feasible. Taking a longer-term view, there may be some advantage to collecting and storing them for future use. It is quite probable that some natural molecules, currently plen-tiful, may become scarce in the future. An example of this is styrene, extracted from a cactus species that is disappearing in Latin America.”

We are studying the impact of this

kind of “cultural revolution” in terms the simplicity of sorting

behavior



Today, Sorting Agents work standing. Even though they wear safety gloves, they are exposed to the ever-present risk

of being pricked by hypodermic needles carelessly thrown out with source-separated waste . They work in cabins that have to be heated and ventilated to

ensure acceptable working conditions, which involves significant energy costs.

Make work easier

The idea of the remote selection system is to refocus operators on higher valued work, namely, the designation of objects, and to transfer them to premises that are easier to heat and where they will be less exposed to the more inconvenient aspects of their job. Moreover, the variety and quantity of waste to be sorted will only increase, and as the throughput of sorting systems will increase to 5,000 objects per hour, that is, 2 objects per second, human capacity to extract the objects “overlooked” by the machine has reached its maximum threshold.

DAD: Allowing SortingOperators to Work from an OfficeCurrently in the pilot stage (scale 1) at the Veolia Propreté sortingcenter in Saint-Priest (France), the Désignation à distance (DAD)Remote selection tool, developed by the Veolia’s R&I, shouldprogress to the industrial pilot phase in early 2010. Designed tophase out all contact between Sorting Operators and waste, itsrollout will improve health and safety conditions in sorting centersand will lift quality control rates to 5,000 objects per hour. This isbecause it is possible to designate twice as many objects as you canphysically grab in a given timeframe.

RESEARCH PROGRAM

Sitting in front of a screen, , the operator selects the object for which he is

responsible, activating its ejection

by a compressed air system.

Thhe touch screen wwitth an i image of the selection belt.



Select rather than extract

The DAD tool works as follows. A camera sends an image of a part of the conveyor to a touch screen. Sitting in front of a screen, the operator selects the object for which he or she is responsible, activating its ejection by a compressed air system. To develop this system, Veolia Environnement researchers first worked on the image capture to make sure the operators were easily able to identify the objects to be removed. They also tested touch screens to choose those that are suitable for the high throughput rates used at sorting centers. Finally, they programmed the computer system to manage the time lag of several seconds between the object’s designation and its ejection. The system’s ergonomics and task organization were also analyzed (see page 8).

TSA2: Project Timeline

Launched at the end of 2005, the auto-adaptive sequential sorting system (TSA2) resulted in a patent being filed in 2006. The project was completed in Spring 2009. Here is a review of the steps in this exemplary development process.

sorting machine

Selection

Extraction

Viewing system

DADRemote Selection – Mimic Diagram



Technological innovations change the way work is done in sorting centers. R&D makes sure that the operators are able to adapt seamlessly.

Workstation ergonomics

Ergonomic studies are carried out prior to application. The studies cover both physical ergonomics to avoid musculoskeletal disorders and cognitive ergonomics. For example, for the DAD remote selection tool, the presentation of the image of the waste on the screen was designed to take account of the operators’ selection strategy. The display time of several seconds takes the time needed for analysis and designation into account.

Work organization

As far as work organization is concerned, the DAD tool factors in the team spirit that is currently the norm among sorting operators. The operator working at the start of the sorting line has a more complex job than his or her colleagues: he or she has to extract from the belt one type of material from many others

–the variety of waste decreases as the sorting progresses. His or her colleagues compensate by rectifying any o v e r s i g h t s . T h i s possibility for mutual c ol l a b o rat io n wa s transposed into the

DAD tool: the same image can pass from one touch screen to the next if necessary. For TSA2, psycho-sociological analyses were carried out throughout the development process, upstream, during the pilot phase, and when starting up the industrial prototype, to help teams adjust comfortably to the change. R&D

worked closely with Human Resources and the CAMPUS to put together the training programs. For the operators, the main change brought about by TSA2 is the sorting throughput rate, and the ejection settings that change every minute. The findings from a series of tests, observations and meetings were used to check how operators responded to the machine, how they reacted to the change in settings and what methods were needed to help them accomplish their tasks. These were based in particular on the analysis of sequences filmed above and facing the workstation. The results revealed that the operators did take ownership of the system and that they are committed to the quality control function. They found the setting changes stimulating, compared with the monotony of sorting targeting a single material. Additionally, the trials revealed that the data system enabled operators to anticipate the following sequence, helping reduce their stress levels. Improvements were made to the ergonomics following the test results.

Social acceptability

The research team is also working on assessing the sociological impact of sorting automation, that is, the social acceptability of taking recycling to the next level. Surveys were carried out on application sectors to determine the barriers to reusing waste plastic and how to overcome them.

METHODOLOGY

People are More Important than MachinesOne of the areas that Veolia Environnement R&I works on involvestaking account of the human dimension when implementing technological changes, not just in terms of ergonomics, organizationand training, but also social acceptability. A team of three people,respectively experts in ergonomics, psycho-sociology and sociology, are involved in research projects precisely for this purpose.

For TSA2, psycho-sociological

analyses were carried out throughout

the development process, upstream, during the pilot phase, and when

starting up the industrial prototype



THREE QUESTIONS FOR…

The first industrial application of the TSA2 auto-adaptive sequential sorting system took place in April 2008 at the Veolia Propreté sorting center at Châteaubernard (France). Located near Cognac, this facility treats an annual 14,000 metric tons of source-sorted household waste.

How has TSA2 been integrated into your

sorting process?

“Combined with an optical sorting machine, TSA2 was installed downstream on the sorting line to separate out five types of material: clear transparent PET bottles, colored transparent PET bottles, opaque flasks (HDPE), food containers and residual paper. It was installed in two weeks, while maintaining the sorting center’s operation at one third of its capacity.”

What improvements have resulted?

“With TSA2, on the one machine, we now sort five categories of waste instead of two. In this way, we get the most out of the optical sorting machine’s operation, raising its utilization close to the rated capacity. The operation rate has remained stable, that is, we have had no emergency shutdowns. Also, we comply with specifications demanded by the recovered waste application sectors. By recirculating waste on the conveyor, we are able to mine the resource far better. Over 12 months, the throughput has increased by 11%, from 4.3 to 4.8 metric tons per hour, enabling us to absorb additional load transferred from other plants in the region suffering outages. Lastly, our productivity is up by 17% because just one operator, instead

of three, is needed to supervise the machine’s sorting quality.”

What has happened to the other two

operators?

“The two positions have been transferred to paper and cardboard sorting quality control to make sure we meet the more stringent technical specifications stipulated by papermakers. The employee roster system introduced means each operator only works on the TSA2 unit for 1 hour 40 minutes every three days. The introduction of TSA2 has shown that it is possible to automate a m e d iu m - s i z e d sorting center with a return on investment of around two to three years without losing any local jobs. So far, on the basis of unchanged employee numbers, our overheads are now more competitive and we are producing better quality secondary raw materials.”

Olivier Scalliet“It’s possible to automate a medium-capacity sor-ting center without losing any jobs locally.”

“ Each operator only works on the

TSA2 unit for 1 hour 40 minutes every three days.

Olivier Scalliet,

Director of

the Châteaubernard

sorting center

[email protected]

Acknowledgments:Our experts Olivier Doyen and Olivier ScallietThe editorial team would like to thank them for their time and contributions.

Publication Manager and editor-in-chief: Fanny DemulierEditor: Xavier DorveauxText: Monik MalissardDesign: Dream OnContact: Communication Department for Research & Innovation 19 rue La Pérouse 75016 Paris - France Tél.: +33 (0)1 71 75 10 88 Fax: +33 (0)1 71 75 05 92 Mail: [email protected] Mail: [email protected]

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Scientiﬁc Chronicles Magazine - · PDF filedistinction between orange peel and a cardboard box, but, it is more difficult to differentiate between recyclable and non-recyclable plastic