Turkish researchers convert plant waste into insulation material
Polyols, one of the basic inputs of polyurethane and polyurethane composites obtained by liquefying plant wastes at Eskişehir Technical University, Eskişehir, Türkiye, Dec. 21, 2022. (AA Photo)

Türkiye's Zero Waste Project, which has recently received global recognition at the United Nations General Assembly, mobilizes the youth to make use of waste



A group of researchers have produced a biopolyol substance by liquefying plant materials such as beet pulp, tomato, pepper, lavender and thyme pulp, and pea and red kidney bean shells in Eskişehir Technical University laboratories and have applied for a patent.

Within the scope of the Zero Waste Project, a group of research students from Eskişehir Technical University (ESTU) obtain polyols, "one of the basic inputs of polyurethane and polyurethane composites used as insulation materials, by liquefying plant wastes which is one of the main objectives of the relevant industry stakeholders," said Murat Erdem, a professor from the university's Chemistry Department.

It was launched in 2018 with a team consisting of Erdem, retired lecturer professor Hayrettin Turk, associate Bilge Erdem, research assistant Emre Akdoğan, graduate students Ahmet Erdem and Duygu Kırat, and chemist Furkan Çolakoğlu.

The research team produces rigid polyurethane foams from biopolyols obtained by liquefying plant materials such as sugar beet pulp, tomato, lavender, thyme and pepper pulp, and pea and red kidney bean pods with a special method.

The academics also add some chemicals to the biopolyol to obtain polyurethanes with some additional performance properties such as improved sound and heat insulation, flame retardancy, and antimicrobial effect.

Experts who produce polyols, which are defined as organic compounds containing multiple hydroxyl groups and are mostly imported, from plant wastes have applied for a patent to the Turkish Patent and Trademark Institute, especially for the product used as heat and sound insulation product in areas such as home appliances, defense, space, aviation and construction.

Erdem explained that polymer materials are mostly produced from petroleum-based and non-renewable resources.

Stating that the environmental problems caused by oil consumption and the increased production costs due to international price policies related to oil, the dependence of polymers on non-renewable resources have become an even bigger problem.

"The use of biological-based resources in polymer production has become one of the most important research topics of our time. When concepts such as renewable-based resources, sustainability, green chemistry and the like are the subject, polyurethanes, which we are working on, are the first polymers that come to mind. Basically, they are obtained by the reaction of diisocyanates and polyols. Polyurethanes, produced and consumed in the global market, are currently one of the polymers with the highest production and consumption. One of the most important inputs for polyurethanes is polyol. Reducing the production and consumption of petroleum-derived polyols and replacing them with biopolyols is one of the main goals of researchers, institutions and companies."

Erdem stated that he has been working with postgraduate and doctoral students on the production of biopolyol and especially on rigid polyurethane foams, which are used extensively in thermal insulation.

Explaining that they have been working for four years to obtain biopolyols from biomass with the acid-catalyzed solvothermal liquefaction method, Erdem said: "We liquefy the compost material used as a mushroom seed host in the production of sugar beet pulp, tomato, pepper, lavender and thyme pulp, pea and kidney bean pods, olive pomace and oyster mushroom production. Grape-based waste material released during the production of hardaliye, the local drink of the Kırklareli region, is among the materials that we can liquefy and obtain biopolyol from," he explained.

Emphasizing that they increase their economic value by making biopolyol from biomass that appears as waste, Erdem said: "We can reach 95% efficiency depending on the type of biomass in the liquefaction processes. We can obtain biopolyol in about two hours, including the separation and purification processes. At the end of the liquefaction process, the waste material produced depends on its efficiency. We evaluate this material, which we call secondary waste, within the scope of the zero waste concept within these processes. In other words, we also add value to the waste of waste."

The Zero Waste Project has led Türkiye's fight against climate change. The initiative primarily aims to bring the country in line with sustainable development principles, prevent uncontrolled waste and leave a "cleaner, developed" country to future generations.

The Zero Waste Project is the new name for recycling in Türkiye since 2017. It has gained traction with a variety of recycling techniques thanks to first lady Emine Erdoğan, who started the national campaign to disseminate the idea of minimizing trash to the public. The project aims to increase Türkiye’s recycling rate to 35% by 2023, while creating employment for some 100,000 people in the recycling industry and saving $2.3 billion (TL 20 billion) yearly.