(from left) Irma Fitriani, Immanuel Nathanael Lumban Gaol, and Ratih Handayani, who are members of the MetaChem-39 team from ITS, the initiators of SCW as PP plastic waste decomposers

ITS Campus, ITS News — A team of students from the Institut Teknologi Sepuluh Nopember (ITS) initiated an innovation related to the potential of Supercritical Water (SCW) to decompose Polypropylene (PP) plastic into an alternative fuel equivalent to gasoline. This is because SCW, a fluid process beneficial for breaking down plastic waste, is still underused in the industrial world today.

The student team members of the MetaChem-39 team are Irma Fitriani, Immanuel Nathanael Lumban Gaol, and Ratih Handayani. Irma revealed that the idea sparked by her team started from a polemic related to plastic waste in Indonesia, which continues to increase every year. “In fact, as of 2021, plastic waste in Indonesia will reach 6.6 million tonnes,” said Irma.

In line with this, Department of Chemistry ITS student added that decomposing plastic waste takes a long time. In addition, the decomposition methods used so far to convert PP plastic, such as hydrothermal pyrolysis, are pretty expensive. “So we try to use SCW as a decomposer to save more expenses,” he explained.

Announcement of Jambi University LKTIN winners by the MetaChem-39 team

Furthermore, according to Irma, SCW is a fluid heating process with low pressure and boiling point right at the critical point of the heated fluid. This method is applied to convert PP plastic into fuel by heating PP plastic in water. Then, at 450 degrees Celsius, the PP plastic will combine with water.

Next, the heating process was stopped, and waited for the temperature in the mixture returned to normal conditions. Then, the water and oil compounds resulting from mixing PP plastic and water separated. “The resulting oil is then examined for its calorific value and shows that the calorific value of oil is equivalent to gasoline,” explained the student who enjoys reading novels.

An illustration of SCW’s idea as a PP plastic waste decomposition which is poured into a scientific paper poster by the MetaChem-39 team from ITS

This research conducted by the MetaChem-39 team has proven that the potential for using SCW as a converter is more efficient than other methods. Besides being a straightforward process, the SCW method is also not time-consuming. “It only takes about 30 minutes for the process,” added the girl from Denpasar.

The research conducted by the guidance team of Dr. Triyanda Gunawan SSi finally bore fruit. The idea outlined in the National Scientific Writing Contest (LKTIN) at the University of Jambi has led the ITS team to win first place. “Hopefully, SCW as a PP decomposition can be applied in the future so that plastic waste is reduced, and the output of this method can be put to good use,” Irma said hopefully. (ITS Public Relations)

Reporter: Nabila Hisanah Yusri