OVERVIEW OF RECYCLING AND REUSE OF USED TIRES 

ANAS IBRAHIM
ABDUL RAHMAN AYUB

Faculty of Civil Engineering
Universiti Teknologi Mara Pulau Pinang (UiTMKPP) 

MOHD SUFFIAN YUSOFF
Idaman Bersih Sdn. Bhd (IBSB)

INTRODUCTION 

The quantity of waste has increased immensely due to rapid growth in the human population and the increasing industrialization. Waste may take the form of solid, sludge, liquid, gases or any combination thereof. Depending on the sources of generation, some waste may be degraded (biodegradable) and some may be non-biodegradable, but the important thing is whether it’s hazardous or not. Hazardous wastes normally pose potential risks to human health and other living creatures/ organisms. Non-hazardous waste can be either degradable (animal, wood, crop and others) or non-biodegradable (foundry, scrap tyres and many others). The constituents of the landfill may vary considerably from country to country. Developing country like India shows a lower proportion of salvageable material (paper, metals, plastics, rubber and etc.) because there is more economical to recycle these materials. In contradiction, more prosperous country the proportion of salvageable materials in the refuse increases. However, as land available for the purpose of wastes disposal become scarcer in the highly populated area together with the demand for the mandatory recycling legislation increases, the trend has begun to reverse itself. Developed country like Japan has placed a major emphasis on the waste reduction, both at the sources and on the recycling effort. It was estimated about 50 % of total waste in Japan were recycled (Cossu, 1990).

However, in the developing country like Malaysia, people awareness on the recycling and waste reduction effort still very low. Consequently, local governments have to deal with the difficulties in managing huge amount of solid wastes produced by industries and domestic users. The scarcity of suitable land for landfill and other related environmental issues associated with the solid waste management become very big issue lately in the country. Landfill in Selangor lately being accused for polluting the river system around the area and a study was conducted to investigate the case. Thus, local governments, relevant agencies and researchers were encouraged towards finding the potentials of reuse or recycle of solid waste materials to preserve a healthy environment and provide a quality life. 

PROBLEMS ASSOCIATED WITH DISCARDED WASTE/ SCRAP TYRE 

Waste tyres can be either legally or illegally dumped or piled. Tyre piles can create many problems such as breeding site for rats, snakes, termites and other vectors. Mosquitoes breed in the stagnant water collected inside tyre piles, creating health threats, amongst others dengue fever, malaria, etc. Uncontrolled waste tyre dumping can trigger epidemic especially to the local people and outsiders if no effective mitigation program taken by the local government or relevant agencies.

Tire piles are also a health hazard because, if set afire either as a result of arson or by accident, they are difficult to extinguish and under uncontrolled conditions will release dangerous oils, extreme radiant heat, heavy smoke and soot (a black powdery or flaky substance consisting largely of amorphous carbon, produce by the incomplete burning of organic matter) thus creating air, ground and water pollution. This can cause considerable damage to the environment. Leachate from waste tyre contained slightly higher in concentration of heavy metals exceed the tolerance limit as per Minnesota Pollution Control Agency (MPCA) can also pose a risk to the ground water system (Ibrahim A. et. al 2006)

 Figure 1: Tyres dumped legally and illegally create environmental problems.

Tyres are non-biodegradable materials and usually needed almost hundred years to be completely decomposed and will take a huge portion of landfill area in the future. In the United State, waste tires consist around 45 % of the landfill area (Ahmed, 1993).This situation was worsen with the scarcity of suitable area for landfill and the people awareness about environmental issue will usually protest against the new landfill area proposed if located near to their residential area or adjacent to the water catchments area. 

Recycling Practice in Taiwan 

Taiwan as well as other countries was striving to manage the waste tyre especially in finding the proper way to dispose it. Because of scarcity and enormous population density, landfill disposal is not appropriate in Taiwan and approximately 23 million people live in only 36, 000 square kilometre area. Most people in Taiwan normally prefer to recycle waste tyres rather than landfill disposal or incineration due to the environmental impact and health risk created by these two methods. Approximately 150,000 tons of waste tyres were generated in Taiwan and this huge amount must be handled properly by Taiwan government.

In Taiwan, tyres generation are roughly divided into three categories. Tyres manufacturing was the biggest portion (65 %), followed by tyres importing (27 %) and vehicle importing contribute around 8 %. Recycling effort in Taiwan can be clearly shown by gradual increment in recycling rate. Since 1998 to 2000, the recycling rate of waste tyres increased from just 48 % to 88 %. (The recycling rate is counted as the amount recycling divided by the amount of processing two years ago). Waste tyres recycling normally divided into two main categories, (1) plant and (2) reuse (figure 2).  

(1) Plant.

Currently there are around 14 resource plants throughout Taiwan, where 10 inclined to dispose by mechanical made rubber powder, 3 plants implemented pyrolysis and 1 plant manufactured tyre-derived fuel.

Normally, a typical tyre composed of 70 % rubber, 21 % steel and 9 % nylon. Waste tyre need to be shredded to 1 inch and as much of steel belt as possible being removed by magnetic separator to produce a quality rubber powder. Application of rubber powder such as re-produced rubber, ground tap and others can be applied.

Another potential economic disposal method for waste tyres is by using tyre-derived fuel method. Tyres are superior to coal in specific energy content. Its residues are also concluded as environmentally regulated. In this case, tyres normally need to be reduced in size to fit the furnace regulation. Tyre-derived fuel (TDF) application is promoted due to the high heating value, clean combustibility and ease for transport or storage.

Pyrolysis, is the energy and resource recovery technology is still under experimental stage in Taiwan. It might be concluded as the most realistic method for the recycling waste tyre disposal. In general, pyrolysis can be defined as the decomposition of organic matter in the absence of oxygen or in an oxygen-starved atmosphere, and converts the polymer waste to useful resource and fuels. Gas, liquid oil and solid residue are usually main products of the pyrolysis process. 

(2) Reuse

Refurbish means that waste tyres are recycled without having extreme initial shape deformation. Tyres are normally used to construct artificial reefs, wave destructors; embankments fill materials, retaining wall facial, slope protection, in tunnel construction, farm utilizing, entertaining equipment, retread tyres and others. Refurbish can be regarded as the best solution for the recycling waste tyres because tyres will be finally dumped somewhere as waste. Refurbish normally gave several advantages compared to the plant recycling because of its economical or cheap technique, direct benefit towards people such as construction materials.

Recycling Practice in Europe Union (E.U) 

In Europe, a link between government and industry on used tyre recovery issues and related information was form in 1995 with Used Tyre Working Group establishment. The Group comprises of the four tyre trade associations and representatives from the department of Trade and Industry and the Environment Agency. In 1999, the Landfill Directive came into force and the UK has until 2001 to introduce the legislative requirements necessary to comply with the Directive. Dumping of whole tyres at the new landfill sites will be prohibited by July 2003 and shredded tyres by July 2006.

European Union is very serious in managing waste tyre. The Landfill Directive clearly indicate the encouragement on recycling of waste tyre as no more waste tyres
(in any form) to be dumped at the landfill site. Table 1 below shows the information on the tyre generation and recycling effort or recovery options for various EU countries. These data were compiled from the information provided by EU trade association for the rubber industry for 1999.

TABLE 1: Tyre generation and use of recovery options for various EU countries (Hallet P. 2001)

 * Car only.       ^ Capacity not actual usage

From the table 1.1, Netherlands has 100% recovery for their tyres (car) with majority for energy recovery (47%). However, we still cannot make a conclusion that Netherlands is the best country practicing recycle for waste tyres because the data available only on car’s tyre only.  Data for overall recovery rate shows that most of developed countries in the European Union practice waste tyre recycling but it seem low for the France and Spain with recovery rate is 39 % and 19 % respectively. Majority of the waste tyre goes to the energy recovery effort followed by retreading industry. Export of waste tyre towards third world countries or others is the third option in waste tyre management and the materials recycling play the last role in waste tyre recovery option in EU. 

Recycling Practice in United State (U.S) 

Total municipal solid waste (MSW) generated in the United State (U.S) has increased from 87.8 x 10⁶ tonnes in 1960 to 195.7 x 10⁶ tonnes in 1990 with the increment  almost 123 % within three decades. Scrap tyres amount was 2.5 x 10⁶ tonnes from the total MSW. In the United State, there are three disposal methods normally practice in U.S for scrap/ waste tyre recovery namely; land disposal, resource discovery and construction application. In the U.S, 25 % of the total 250 million waste tyres were recycled. Majority of them will be stockpiled or landfilled. Whole tyres normally do not lend themselves to compaction, thus reduce the landfill capacity as well as rise to the surface with the time and damage the final cover. This situation worsen with the tyres are normally take hundred years to be decomposed. Therefore, almost 78 % of these waste tyres wind up in overcrowded landfills, scattered in the empty lots, highways and illegal tyre dumps (Cecich, V. et al. 1996).

From the figure 3 above, the actual amount of export for scrap tyre were 15 million, civil engineering applications (12 million), Punched/ Stamped product (8 million), ground rubber (6 million), agricultural and miscellaneous (3.5 million) and the largest amount of 130 million were for tyre derived fuel. Figure 4 below shows some applications of waste tyres in civil engineering construction project.

Scrap tyres have been successfully utilized as construction materials in civil engineering applications. Study also had shown significant benefits from the utilization of scrap tyres in civil engineering applications particularly in road construction such as lightweight and improvement of backfill properties. Although these recycling, reuse and recovery efforts consume about 70 % of discarded tyres every year, they have not significantly reduce the amount of tyres in landfills and illegal dumping (Bernal A, 1996). 

Recycling Practice in Malaysia 

Malaysia's natural rubber production in 2004 totalled 1.1 million tones compared with 0.9 million tones in 2003. The rubber products industry consumed 506,000 tones of rubber in 2004. The largest consumers of rubber were latex products, followed by industrial and general rubber products and tyres. The rapid growth of the industry has enabled Malaysia to become the world's largest consumer of natural rubber latex.

In the tyres sub-sector, there are currently four major tyre manufacturers producing passenger car tyres, truck/light truck tyres, earthmover and grader tyres. In 2004, this sub-sector contributed RM335 million (US$88.16 million) to the country's export earnings and employed more than 6,800 workers. Production of tyres is geared for the domestic market. The industrial and general rubber products sub-sector comprises 188 companies producing a wide range of rubber products such as mountings, beltings, hoses, tubings, seals, and sheetings for the automotive, electrical & electronics, machinery & equipment and construction industries, largely for the domestic market. In 2004, exports of industrial and general rubber products amounted to RM746 million (US$196.32 million).

Statistics for Malaysia produced by Malaysia Automotive Association (MAA) indicated more than 600% increment in number of registered vehicles since 1980. The number of registered vehicles reached half a million in 2005 and this number is expected to be higher with the current government’s policy on the automotive industry (DAN). Malaysian industries produced 14,685,500 of pneumatic tires and 17,755,500 of inner tubes, while importing tires worth RM 248.7 million in a sole year 2000. Of that, tire replacement market average is 1,257,000 pieces per month, with 35-40% goes to retread market and 65-70% for disposal dumping or other use (JPM, 2000). In 2004, tyre export worth RM 335 million and this sector employed 6,800 workers (MIDA, 2006). The figure mentioned indicated that tyre industry and automotive industry in Malaysia is growing well together with the tyre waste amount.

It’s difficult to determine the actual number or the tyre generation and the recovery rate because there is no systematic data collection. Basically in Malaysia, the destination of waste tyres is dumping area either legally (landifill) or illegal dumping site; reuse (retreading industry, artificial reef and etc.) and recycle (send to the plant for tyre shred production, chop).

According to the data available from the Pulau Burong landfill operator, the amount of whole tyres landfilled the area were approximately 80 tonnes per month. . The total amount of waste production in Pulau Pinang was 1600 tonnes for the whole state per day. Around 43 % of total wastes were come from the Island and each person in Pulau Pinang is estimated to produce around 0.9 – 1.1 kg per day. The cost for waste collection, waste transfer and landfilling is around USD 35.00 per tonne and USD 632,000.00 per month. According to the landfill operator, the life of Pulau Burong landfill can last approximately 3 – 4 years. However, the life can be extended to the 24 years if wastes can be diverted (recycling). Therefore, due the scarcity of land and the high cost of solid waste management, state government cannot afford to relax on the recycling program. The strategy and planning to have higher rate of waste recovery (recycling) was implemented in the three phases by Penang State Government.

1. Phase One: Pilot Project of the Community Recycling Programme and Awareness Campaign from 31st July 2001 to 30th July 2002 (one year)

2. Phase Two:  Information Collection and Dissemination Programme from 31st July 2002 to 30th July 2003 (one year), and

3. Phase Three:  Expansion of the Community Recycling Programme from 31st July 2003 to 31st December 2005 (two and a half years).

Recycling rate for Pulau Pinang is 9 %, 5% for Kuala Lumpur and the average is 3 % for the whole Malaysia. In Pulau Pinang  23,000 metric tones wastes were diverted from  landfill and it saved USD 805,000 in costs in 2003. Therefore, it’s vital now for us to have a comprehensive system in managing solid waste. The plan must clearly show the process of reducing, reuse, recycling, intermediate process and disposal of solid wastes. 

DISCUSSION & CONCLUSION 

Malaysia and particularly Local governments must have a proper plan to manage the solid waste. Highly populated state like Pulau Pinang and Selangor are now facing the problems associate with the solid waste and landfills. The land scarce due the rapid of population growth leads Selangor state to option incinerator. However, Malaysian educated people were against it as they believe that the incinerator will contribute to the severe health hazardous environment. This issue shows that local government must provide a better alternative to manage the solid wastes.

The main issue in Malaysia is to educate people toward recycling. Government had launched the series of campaign, but it seemed not very effective to achieve the target. The campaign through electronic multimedia, posters and papers were not followed up by the satisfactory recycling facilities. In certain big residential area, no recycling facility is provided. Malaysian people normally did not willing to carry their rubbish a few kilometres to reach recycling centre. Insufficient recycling facilities will demoralise beginners in nurturing the recycle habit.

Government must sometime take non-popular decision by making a mandatory recycling legislative. The available law on the environmental must be strictly enforced. Local government can now started to plan on prohibiting non-biodegradable wastes, such as tyre from being dumped in the landfill. The incentive must be provided for the recycling operators to improve their technology in recycling and thus their production. It will encourage recycling effort in the country.

In conclusion, Government should encourage reused and recycle research, and the technology development that offer opportunity for smart management of the solid waste. This will influence on the better conservation of natural resources, to give a great future.