Going green with chemicals
Wageningen Climate Solutions
Photography: Shutterstock
BY Arjan Paans - September 2019
Solvents, paints and coatings are by-products of the petroleum industry. Now that we have to wean ourselves off fossil oil based products over the next few years, the chemicals industry needs to go green and so it is exploring products based on biomass. WUR scientists are working on these alternatives.
Wageningen is more than just agriculture, says Jacco van Haveren, Biobased Chemicals programme manager at Wageningen University & Research. If we want to know how Wageningen’s research can help curb CO2 emissions, it makes sense to look at industry and the energy sector too, he says. “When you talk about CO2, agriculture accounts for 20 to 25 per cent of emissions, while industry and the energy sector are responsible for 60 per cent. This isn’t just the direct energy consumption, but also the effect of the production methods and the raw materials and chemicals at source. That’s why it is important to look at biobased products.”
Biobased products are made partly or entirely from biomass, such as sugar, starch or wood, or their associated by-products, such as sugar beet pulp. If these raw materials can be produced sustainably, they could be a green alternative for the chemicals, materials and fuels that are currently obtained from fossil sources, and consequently help reduce greenhouse gas emissions.
A petrochemical industry refinery — bad for the environment and health. Photo: Igor Plotnikov / Shutterstock
Green potential: from asphalt to cosmetics
Van Haveren says biobased products have huge potential. “People often think it’s just about packaging, or paints and adhesives, but it’s much bigger than that. Some examples are car parts, insulation materials, asphalt, lubricants, cosmetics and cleaning agents. Calculations show that you would eventually be able to replace 350 million tons of fossil-fuel products globally with biobased alternatives.”
One of the applications for which biobased raw materials are well suited is producing chemicals such as solvents. Calls to speed up research into biobased chemicals have become louder because of the climate debate. After all, many solvents are oil industry by-products. Now that we will have to wean ourselves off fossil oil based products over the next few years, the search for alternatives to petrochemicals is becoming increasingly urgent.
BIOBASED SOLVENTS NOT ONLY BENEFIT THE ENVIRONMENT, THEY ARE ALSO BETTER FOR HEALTH
Alternatives to toxic solvents
What is more, many solvents are bad for your health. In Wageningen, researcher Daan van Es has been working for years on biobased alternatives to the solvents toluene and NMP (N-methyl-2-pyrrolidone). Toluene and NMP are widely used in the manufacture of products such as paints, coatings, adhesives, medicines and agrochemicals.
These two compounds are on the list of ‘Substances of Very High Concern’ compiled by the National Institute for Public Health and the Environment (RIVM), which means the Dutch government believes use of these compounds should be minimized.
Cleaning agents, pills and asphalt contain hazardous compounds and fossil-fuel products that could be replaced by biobased alternatives. Photos: Shutterstock
Good for the environment and health
Daan van Es: “Toluene is a very useful solvent that is produced in quantities of millions of tons at a time, so it is important for industry. However, it is probably neurotoxic and can damage the nervous system. NMP is another excellent solvent, but it has been proven to be reprotoxic, which means it can affect the reproductive system. That is why there is increasing pressure to phase it out.” In other words, biobased alternatives to toluene and NMP would not only help reduce greenhouse gas emissions, they would also have significant health benefits.
Furthermore, we are already seeing an increase in the use of bioplastics. Biobased solvents could help in the efficient recycling of these bioplastics at a later date. Toluene and NMP, on the other hand, are unsuitable for that purpose, says Van Es.
Sugar beet pulp: fast growing and versatile
In the RESOLVE project, funded by grants from the European Union, Van Es and his team are working with York University on the search for non-toxic and sustainable alternatives to toluene and NMP. A number of biobased solvents have been developed on the basis of cheap, easily available sugars such as those found in sugar beet pulp.
Why sugar beet pulp? Van Es: “Sugar beet is already grown in large quantities, with a consistent quality. It is the most efficient raw material for the purpose as it is such a fast-growing crop and you can do so many different things with it. You might get the same effect with some rare plant from the Himalayas, but that will never be enough. This is an industrial problem that you need to tackle with a realistic approach.”
Arguments that the use of biobased products would be at the expense of food production are misinformed, says Jacco van Haveren, at least where chemicals and materials are concerned. “The Netherlands grows millions of tons of sugar beets and potatoes every year, not all of which is needed for food. What is more, the production of sugar beets also generates millions of tons of sugar beet pulp that is not suitable for food.” That residual stream is currently often treated as waste. Van Haveren: “As far as fuels are concerned, we can only replace a limited proportion with biofuels, but biomass surpluses and by-products are perfectly suited for the chemicals industry.”
In biotechnology, scientists research natural alternatives. Photo: Shutterstock
Obstacles
It would therefore seem both the problem and the general solution are clear. So why haven’t all solvents been replaced by biobased chemicals? Van Es lists a number of obstacles. First there is the price of the product, which is still in the development phase. “As long as there is no ban in place, the need to develop a replacement is not so urgent. After all, toluene is an incredibly cheap residual product from the oil industry. The first factory you set up for a biobased alternative is only going to cost money. Then the performance has to be right, and finally manufacturing the product in the required quantities has to be viable.”
Despite three years of research, the project is far from finished. Van Es: “It will take at least another five to ten years before this is up and running on an industrial scale. Chemicals production requires a huge amount of capital, which makes it a slow process. It is also almost impossible to find an alternative compound that behaves the same in every application yet is not remotely toxic. Even if the process can be scaled up and the applications work amazingly well, it will still take a long time to register and test the compounds. This will cost many years and many tens of millions of euros, if not hundreds of millions.”
THE NETHERLANDS GROWS MILLIONS OF TONS OF SUGAR BEET AND POTATOES EVERY YEAR, NOT ALL OF WHICH IS NEEDED FOR FOOD
Sugar beet is an efficient raw material and an ideal biobased alternative. Photo: Photoagriculture / Shutterstock
Sticks and carrots
The European Union should really name a date by which the current compounds have to be phased out, thinks Van Es. As that is not yet the case, the first manufacturer to invest money in alternatives is running an enormous risk. “The industry will only take action once a date has been announced for banning these compounds. If you combine that with a fund for subsidizing the further development of alternatives, things could move really fast. In other words, you need sticks and carrots.”
In addition to the costs and lack of legislation, Jacco van Haveren points to another factor currently impeding the large-scale development. “We are suffering rather from the oil prices. High prices are good for biobased chemicals. There was a lot more interest in investing in alternatives when oil was at 120 dollars a barrel compared to now, with prices around 60 to 70 dollars. On the other hand, there are signs that public opinion is now very much in favour. The demand for natural materials among multinationals and brand owners is rising, and the debate about plastic soup is playing a role too. But all in all, we think it will take another 10 to 20 years before biobased solutions experience a genuine breakthrough.”
