The benefits and challenges of shifting to plant-based oils in the chemical industry

By Andrei Mihail

With their long degradation time, unsightly appearance and negative effect on the environment, single-use plastics are no longer simple candy wrappers or straws. Rather, they are seen as symbols of a culture so focused on convenience that it chooses to destroy its own environment.

Plastics are just one aspect of the petrochemical industry, the sector of the chemical industry that produces a wide range of products made from raw materials derived from petroleum and natural gas.

Progress made in the use of plant-based alternatives is remarkable, and proves that we can meet people’s demand for a high quality of life while not relying on a finite resource.

From chemicals and plastics to synthetic rubber, resins, fibers, these diverse materials are used in a variety of applications that are unavoidable in daily life, such as packaging, construction, transportation, agriculture, and consumer goods.

But how did we get here? And how can plant-based oils help us overcome this predicament?

• Brief history of the petrochemical industry
• The issue with petrochemicals
• The alternative: plant-based solutions
• Plant-based-materials
  • Bioplastics
  • Lubricants
  • Solvents, surfactants or emulsifiers
  • Polyurethane production
• Efficiency and sustainability

Brief history of the petrochemical industry

While plastic was invented in 1869, when John Wesley Hyatt invented celluloid, the first synthetic plastic, demand for petrochemical products skyrocketed during the second world war. Fuel was needed to power tanks, airplanes and trucks. Coal was needed for factories and trains. Plastic was used to make items such as gas masks, helmets, parachutes, insulation for aircraft, and personal items such as toothbrushes and combs. Additionally, the development of new products, such as synthetic rubber, was spurred by the war effort, and helped to establish the petrochemical industry as a major player in the global economy.

Following the end of the war, many factories had to repurpose themselves for civilian goods. Suddenly, instead of making war Jeeps, they were making personal automobiles. Instead of parachutes, they shifted production to synthetic clothing items like nylon stockings. The increased availability of synthetic fibers, the associated reduction in cost and the huge marketing drive made these materials increasingly popular for use in clothing, linens, and other household items. Almost overnight, the petrochemical industry became present in all aspects of life.

The issue with petrochemicals

Long story short, the petrochemical industry has severe environmental and economic shortcomings. Environmental impact: The production of petrochemicals has a significant impact on the environment, including greenhouse gas emissions, air pollution, water pollution, and soil contamination.

Finite fossil fuel resources

Production of petrochemicals relies on finite fossil fuel resources that are being depleted over time, leading to concerns about energy security and sustainability. Even as the intensity and efficiency of prospecting for and extracting from new deposits increases, this seems to only delay the inevitable.

Dependence of fossil fuels as feedstock means that the prices of petrochemicals are influenced by a number of factors, including global demand, production costs, and geopolitical tensions, which can lead to significant price volatility, which can make vital products unaffordable.

Petrochemicals health and safety risks

Production, transportation, and use of petrochemicals can pose significant health and safety risks, including exposure to toxic chemicals, fires, and explosions.

The petrochemical industry has a significant impact on the environment, both in terms of the extraction and refining of petroleum, as well as the production and disposal of petrochemical products.

The greenhouse gases, such as carbon dioxide and methane, released from the burning of fossil fuels used in the production and transportation of petrochemicals contribute to global warming and climate change, while the refining and production processes often result in the release of pollutants into both air and water, such as sulfur dioxide, nitrogen oxides, and volatile organic compounds, leading to air and water pollution. It is also a major contributor to the generation of plastic waste, with a significant amount of it ending up in natural environments, causing harm to wildlife, marine life and their habitats.

Finally, oil spills and other accidental releases of petroleum and petrochemicals can have devastating effects on local ecosystems, wildlife, and human communities.

The alternative: plant-based solutions

Up until a while ago, it seemed like humans might be stuck in a very unfortunate situation. Petrochemical products are the basis of modern life, with applications in all fields, from medicine to transportation, without which we could hardly imagine these fields. Progress made in the use of plant-based alternatives is remarkable, and proves that we can meet people’s demand for a high quality of life while not relying on a finite resource.

Plant-based materials

The main forms of plant-based materials used to create alternatives to the petrochemical industry are:

• Cellulose: derived from plant fibers such as wood, cotton, and hemp, it is used to make bioplastics, paper, and textiles.
• Starch: a carbohydrate found in crops such as corn and potatoes, is used to make bioplastics, adhesives, and coatings.
• Proteins: extracted from crops such as soybeans, they can be used to make biodegradable plastics, foams, and adhesives.
• Lipids: oils derived from plants such as soybeans, canola, and palm can be used to make biodegradable plastics, lubricants, and personal care products.
• Lignin: a byproduct of paper making, it can be used as a binding agent in composites, and as a fuel.

In this context, plant-based oils have been gaining increasing attention. Oils are made of lipids, and often in their production a high amount of waste protein is generated, such as during soybean oil production or peanut oil production. This means that the same existing supply chain that only produces oil and waste (which is sometimes reused as animal feed or composted) could be adapted to also produce plastics, lubricants, foams, adhesives and personal care products.

Plant oils are renewable, easily available, biodegradable and non-toxic resources. The properties of the materials created can be changed by using different kinds of vegetable oils, as well as through various organic or synthetic additives.

Below, we will discuss some of the main products made from either plant oils.

Bioplastics

Plastics are one of the most researched and discussed areas where plant-based oils can play a key role in reducing environmental impact. Petroleum-based plastics are widely used in a wide range of applications, but they are often toxic to both human and non-human life, and they are not biodegradable and can take hundreds of years to break down in the environment. Plant-based plastics, on the other hand, have reduced toxicity and can be designed to be biodegradable depending on the specific needs of the final product and made from renewable resources such as soybean oil or protein.

One role that the vegetable oils industry plays in bioplastic production is through Seed Oil Cakes (SOC). Seed cakes are what is left of the seed following the extraction of edible oil. They represent roughly 50% of the original seed’s mass and are most often used as animal feed or, through composting, as fertilizers. However, because they are rich in fibers, proteins and secondary metabolites, SOCs are a promising raw material for biorefineries able to produce high value-added products according to circular economy paradigms.

Plant oils can also be used to modify the properties of plastics. Epoxidized vegetable oils for example are used as plasticizers and hydrogen chloride acceptors for PVC, improving the flexibility, workability, and distensibility of rigid polymeric materials, and thus increasing their utility in various applications. Soy ketal derived from fatty acid methyl ester and synthesized through epoxide intermediates has been shown to exhibit better thickening and aging behavior compared to petroleum-based plasticizers.

Lubricants

Lubricants are used to reduce wear or tear of two surfaces in contact and moving relative to each other and are vital for the adequate functioning of essentially any machine with constantly moving parts. The potential of vegetable oils in this area has been researched for several years. Vegetable oils have good lubrication properties but have low thermal and oxidative stability. The properties of palm kernel oil (PKO) as a lubricant have been studied and shown to be promising, with properties comparable to heavy duty and light duty oils. However, PKO has limitations such as poor low-temperature properties and susceptibility to oxidative degradation, which would require more frequent maintenance and limit the situations in which it can be used.

Through epoxidation, the properties of vegetable oils are changed. For example, epoxidized castor oil has improved lubricity properties. Various properties, such as oxidative stability and fluidity at low temperatures, have been improved through chemical treatments. This shows that the future of lubrication is plant based.

Solvents, surfactants or emulsifiers

For example, they can be used to produce industrial chemicals such as solvents, surfactants and emulsifiers, which are used in a wide range of products, including paints, adhesives and cleaning products. When compared to petroleum-based chemicals, plant-based oils can offer improved stability, lower viscosity and better biodegradability, leading to increased efficiency in production and reduced waste.

Polyurethane production

Vegetable oils can be converted into polyols through the reaction of epoxygenated fatty acids with low-molecular-weight alcohols or acids, which opens the oxirane ring.Used frying oils can also be converted into polyol through epoxidation and reaction with diisocyanate. The preparation of fatty acid-based polyols requires a three-step reaction, where the amount of catalyst used, temperature, pressure, molar ratio of reactants, and reaction time are important parameters.

The resulting polyols can be used in various applications such as flexible polyurethane foams, coating processes, and flooring systems, as well as for production of adhesives and casting resins. From consumer goods to thermal insolation and industrial uses, plant oils can fulfill a variety of functions.

Efficiency and sustainability

In conclusion, plant-based oils offer a wide range of benefits for industrial and commercial applications, including improved efficiency, reduced environmental impact and greater sustainability. They are a versatile and renewable resource that can be used to produce a wide range of products, including industrial chemicals, lubricants and plastics.

Even their byproducts have multiple uses, making them a key part of a future circular economy. With ongoing research and development, plant-based oils have the potential to play an increasingly important role in reducing our dependence on petroleum-based products and creating a more sustainable future.