After conducting a successful experiment on recycling plastic waste, researchers are now looking to commercialise the process named ‘tertiary recycling’ as it is not only the best option to solve the problems concerning disposal of plastic waste but it also reduces greenhouse gas emissions.
The test was conducted last year at the Hussain Ebrahim Jamal (HEJ) Research Institute of Chemistry under the supervision of King Fahd University of Petroleum and Minerals (KFUPM) Professor Dr Farhat Ali.
Tertiary recycling, also called feedstock recycling, returns plastic to their constituent monomers or to their basic hydrocarbon feedstock. The resulting raw material is reprocessed either into plastic or other products of the oil refining process.
In Pakistan, plastic is recycled via primary and secondary recycling, also known as mechanical recycling.
“This is a thriving industry that provides an opportunity to scavengers (mostly Afghans) to collect, do kerb-side sorting of different plastic goods and sell them to different manufacturers,” said Farhat Ali.
“Our proposal of converting plastics to fuels is tertiary recycling and to the best of my knowledge there is no such industry in Pakistan,” he said.
Researcher Salman Qureshi said tertiary recycling is occurring more and more today because of the need to tackle high levels of waste contamination.
According to him, this concept of feedstock recycling is based on thermal and/or catalytic breakdown of plastic waste to a mixture of basic hydrocarbons, which can be valuable either as a fuel or in raw form.
“Crude oil obtained from plastic waste has better properties than the one you get from underground. The reason is that plastic bags are made from petroleum, so the crude obtained has fewer trace of metals like sulphur,” said Qureshi, adding since it is a closed system, net emissions are almost zero.
As for the cost of commercialising the process, he said the raw material is absolutely free. “We only need to ensure a regular collection of waste and its transportation. There is also no need for the segregation of different types of plastic. A single process works for all kinds.”
This stupendous amount of solid waste generated could be collected at a minuscule cost and the process could be undertaken with existing resources (oil refineries) without any investment, he added.
The team initially approached a few refineries but did not get the response they expected. “We tried to persuade the refineries in Karachi to undertake a trial run but no one was willing to cooperate,” said Farhat Ali.
“Moreover, our feasibility study for an independent processing plant showed a low (3.25%) return on the initial high cost of investment, so the profitability is not very attractive.”
The investors, to put it correctly, are rather sceptical, said Dr Raza Shah of HEJ. “But we have had success with a company from the Netherlands and recently signed an agreement,” he said. “They are funding the project worth $20,000. We have started work from January 1, and it will take about three years to reach the commercial level.”
The main issue is the collection and segregation of plastic material from the other stuff found in mixed waste, according to Farhat Ali.
Solid waste in Pakistan is generally composed of plastic, rubber, metal, paper, cardboard, textile, glass, food, animal waste, agriculture waste, wood and bones.
“The management of solid waste as a whole is very inefficient as only about 50% of total waste is collected. There is no separate arrangement for recyclables,” said Ali.
He said the scavengers play an important role as they separate recyclables at various stages of waste management. In order to put up a processing plant for tertiary recycling of plastic waste, a constant supply of feedstock is essential. Therefore, it is necessary to establish an efficient system for the collection of plastic waste.
The present arrangement of mechanical recycling is, therefore, more attractive and profitable for the domestic industry.
For Qureshi, the focus should also be on accepting ground reality and giving weight to solving the problem. “The government should launch a public awareness programme to emphasise the need for promoting a healthy environment.”
The green technology is so far available only in Germany, Japan and the US, while Australia and the UK are still working on it.