Wondering what “bio-based” actually means for the products you use? These bio-based chemicals examples cover plastics, solvents, surfactants and lubricants made partly or wholly from sugar, plant oils and citrus peel.
If you want the bigger picture first, start with this explainer on what is the bioeconomy and how biomass fits into it.
| Item | Value |
|---|---|
| Global solvents market (Fraunhofer ISI estimate) | 19.7 million mt/year |
| Bio-based share of solvents (2013 report) | 1.5% |
| Share of solvents that could come from biomass | At least 12.5% |
| PLA production capacity in 2010 | Exceeded 110,000 mt/year |
| Start of industrial PLA production | 1994 |
| Biolubricant price versus conventional lubricants | 2 to 3 times higher |
The figures above come from CHEManager’s May 2013 report on bio-based chemicals and its July 2012 feature on bio-based polymers, lubricants and surfactants. They are dated estimates and can change, so check the sources before you rely on them.
What makes a chemical bio-based
A bio-based chemical is made wholly or partly from renewable biological sources instead of fossil fuels. NNFCC’s biobased products page describes biobased materials as products wholly or partly derived from renewable biological sources, and lists crops, forestry products, algae and food or industrial by-products as the biomass behind them.
Chemistry takes a small slice of oil use, yet it is a place where a change of feedstock can matter. CHEManager noted in July 2012 that only about 8% of total oil production output goes to the chemical industry, and it listed the benefits of raising the renewable share:
- A reduction in carbon dioxide emissions from fossil sources.
- Access to complex structures produced by natural synthesis.
- Higher consumer acceptance of bio-based products.
Those benefits assume that bio-based products stay price-competitive and perform at least as well as the originals. That is why many early examples sit in niche markets, where a special property justifies a higher price.
CHEManager’s May 2013 report describes two approaches to making bio-based chemicals:
- Use the high functionality of natural molecules with only moderate chemical modification. Biopharmaceuticals, bio-based polymers and products from fats and oils follow this route.
- Build integrated biorefineries that convert biomass into a series of chemical raw materials and fuel products, ideally using the whole plant.
Plastics: PLA and bio-based polyethylene
Polylactic acid (PLA) is the best-known bio-based plastic. According to CHEManager’s May 2013 report, sugar or starch is fermented to make lactic acid, a chemical step turns it into lactide, and ring-opening polymerization then builds the polymer.
PLA has properties similar to conventional mass-produced thermoplastics and can run on existing production lines. Because it is compostable, it suits throwaway packaging such as beverage cups and food trays, but its low melting point rules it out for items exposed to heat. Industrial production began in 1994, and worldwide capacity exceeded 110,000 mt/year in 2010, as the same report states.
Bio-based polyethylene takes a different route. Ethylene, the platform chemical, is made from renewables, so the existing chains for making plastics and handling them at end of life can be reused. CHEManager reported that Braskem of Brazil launched production in 2010 using bioethanol as the base, and that this polyethylene is not biodegradable but has established recycling paths, at least in Europe.
Biopolymers made directly by microbes came first. The 2013 report says polyhydroxybutyrate (PHB), which bacteria use to store energy, reached the market in the 1990s under the trade name Biopol. Today the usual approach is to extract monomers from renewable feedstock and build polymers from them.
Those bio-based building blocks feed many other plastics, according to CHEManager’s 2012 feature:
- Succinic acid and castor-oil polyols go into bio-based polyesters, and polyols also go into polyurethane.
- Dehydrating lactic acid produces acrylic acid, a monomer of polyacrylic acid.
- Butadiene, used in synthetic rubber, can be made from ethanol.
- Castor oil derivatives are used in polyamides.
Solvents from citrus rind, lactic acid and plant by-products
Solvents show how much room there is to grow. In a study, the Fraunhofer Institute for Systems and Innovation Research estimated the global solvents market at around 19.7 million mt/year. As of CHEManager’s May 2013 report, at least 12.5% of that volume could be made from biomass, but the actual figure was only 1.5%.
The same report lists these bio-based solvents:
- Fatty acid methyl esters, which are also used in biodiesel.
- Methyl lactate and ethyl lactate, esters of lactic acid.
- D-limonene, obtained from the rind of citrus fruits.
- Tetrahydrofuran (THF), made from bio-based succinic acid or from furfural, a by-product of the cellulose industry.
Most solvents are still based largely on fossil feedstock. Sustainability and environmental protection concerns are expected to shift the mix, according to the same source.
Surfactants in cleaning products and cosmetics
Surfactants have a water-loving part and an oil-loving part. In the bio-based versions described by CHEManager in May 2013, at least one of those parts comes from renewable resources.
- The oil-loving group is usually made from coconut oil or palm kernel oil.
- The water-loving group is normally made from carbohydrates such as sorbitol, sucrose or glucose.
- Use of animal fat has decreased significantly.
Thanks to good biodegradability and low to zero toxicity, they are used by the paint, cosmetic, textile, agricultural, food and pharmaceutical industries. As of that May 2013 report, consumer products already on sale included detergents with enzymes and cosmetics ingredients.
Shoppers seem open to the idea. The report cites a survey released by DuPont in which more than three-quarters of the urban Chinese consumers interviewed said they would definitely or likely buy bio-based products (source).
Lubricants: bio-based is not the same as biolubricant
The two terms are easy to mix up. CHEManager explains that a biolubricant is any lubricant that is readily biodegradable, whether it is bio-based, mineral-based, made with recycled oil or synthetic.
Bio-based lubricants, by contrast, are generally made from vegetable oil. Depending on requirements they are used in their native state (natural ester) or chemically modified (synthetic ester). Their long service life, low toxicity and fast biodegradability make them attractive for environmentally sensitive uses.
Cost is the sticking point. CHEManager’s 2012 feature reports that biolubricants cost 2 to 3 times more than conventional lubricants, citing a market study by Global Industry Analysts. It also cites Germany’s agency for renewable resources: of more than 1 million MT of lubricants used each year in the country, 35,000 MT were biolubricants (3%).
What to check before you trust a bio-based label
A renewable origin does not settle every question. Keep these points in mind when you compare products:
- Bio-based is not the same as biodegradable. Bioplastics are a heterogeneous group that includes bio-based plastics as well as fossil-based plastics that are biodegradable, and bio-based polyethylene is not biodegradable.
- Cost and performance still limit uptake. NNFCC says biobased materials face challenges in scalability, cost and performance.
- End of life matters. CHEManager noted that complete recycling systems are needed for resource-efficient production and use, and its report on bio-based chemicals said that, at the time of writing, compostable PLA was incinerated because of a lack of infrastructure.
Both sources are linked above: NNFCC for the first two points, and CHEManager’s 2012 feature for the first and third.
The trade-offs of plastics in particular are covered in more detail in this look at bioplastics pros and cons. If you want to know how these materials relate to emissions, read about bioeconomy and climate change.
Frequently asked questions
What are the most common bio-based chemicals examples?
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Reported examples include PLA and bio-based polyethylene plastics, solvents such as ethyl lactate and D-limonene, surfactants made from coconut or palm kernel oil, and lubricants made from vegetable oil.
Is a bio-based chemical always biodegradable?
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No. Bio-based describes where the carbon comes from, while biodegradable describes what happens at end of life. Bio-based polyethylene, for example, is not biodegradable, and some fossil-based plastics are.
Why are bio-based chemicals not everywhere yet?
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Cost, scale and performance are the main hurdles. Many examples sit in niche markets where a special property justifies a higher price, and the sources in this guide are dated 2012 and 2013, so the market may have moved since.
What is a biorefinery?
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A biorefinery works like a petrochemical refinery but starts from biomass. It converts biomass into a series of chemical raw materials and fuel products, with the goal of using the whole plant instead of only parts.
