Biosolvents solving challenges– from dry cleaning and cleaning shorelines to biomass and biofuel production

Biobased solvents are on the rise with more demand for them now than ever before. What used to be an alternative to petroleum-based solvents, biosolvents are now looked at as an environmental win-win as well as a win for better performance and safety with lower toxicity issues.

Just recently, United Kingdom based Circa Group’s biobased solvent Cyrene was used to produce the highest-quality graphene ink ever achieved, as reported in Nuu in January. According to Circa, the findings have “far-reaching commercial applications and open up multi-million-euro market opportunities for graphene in applications such as advanced composites and polymers, coatings, batteries and supercapacitors, 3D printed materials and functional fluids. More specifically, graphene inks can directly be applied to materials like textile and paper and used in many applications including transistors, sensors, antennas, radio frequency identification (RFID) tags and wearable electronics.”

Produced from cellulose, Circa’s Cyrene was able to outperform traditional solvents, including the toxic chemical N-Methyl-2-Pyrrolidone. And that’s a win-win.

The cleaner and greener, the better

Biosolvents are also increasingly being used in various cleaning applications, like oil recovery on shorelines. As reported in Nuu in June 2018, United Kingdom-based Nanotera Group launched plant-based surfactants for enhanced oil recovery. The cleaning agents reduce processing time by performing quickly.

“The oil industry has been slowly going through a phase of transformation over the last decade pulling away from chemical-based cleaning products and increasingly calling for plant-based renewable products that work highly effectively without the potential to harm users and the environment,” says Saba Yussouf, Director at Nanotera. “Pan-globally this is a topic that is high on every government’s agenda. Eventually, it is expected that legislation will make this change compulsory in most countries.”

The products can be used in enhanced oil recovery, tank cleaning, equipment maintenance, oil herding, oil/water separation and rig maintenance. They clean by reducing the surface tension of the oil. The surfactants break down organic contaminants, oil and water emulsions and remediate hydrocarbons without polluting the treated product.

Dry cleaning, historically known for using toxic chemicals to make your shirts clean and crisp, is also looking at biosolvents as a way to make their methods greener and get consumers less afraid of the chemicals used in the dry cleaning process. As reported in Nuu in June 2017, German textile care company Kreussler introduced a biobased solvent for dry cleaning dubbed SOLVON K4.

The solvent is partially derived from corn and took two years to develop, says Richard Fitzpatrick, Vice President of Kreussler. “It offers the same performance and safety, but also creative marketing approaches and increased opportunities for eco-labeling and certifications,” he adds.

SOLVON K4 is chemically identical to its predecessor solvent. The switch to biobased solvent was set into motion by a chemist at renewable chemicals company Green Biologics whose local dry cleaner was using Kreussler’s dry cleaning products. Green Biologics had just brought a renewable chemicals plant online in Minnesota, and the chemist identified Kreussler’s products as candidates for renewable production routes.

“We hope that our innovative new version of SOLVON K4 will the carry the first-ever USDA bio-preferred label in the industry,” says Fitzpatrick.

Biosolvents in the mainstream

Getting biosolvents into mainstream production has been a challenge but it is moving forward, with Circa Group’s latest green light from the EU a hugely positive sign that it’s just a matter of time before biosolvents will be a standard accepted practice. As reported in The Digest in December 2018, Circa Group received authorization from the European Chemicals Agency (ECHA) to manufacture or import up to 100 metric tons/year of its bio-based solvent Cyrene in the European Union, after receiving REACH Annex VIII approval.

A chiral dipolar aprotic solvent, Cyrene was developed in conjunction with the Green Chemistry Centre of Excellence (GCCE) at the University of York. Cyrene is a two-step conversion of waste biomass, produced at Circa’s large-scale prototype plant, built in partnership with pulp and paper company Norske Skog in Tasmania, Australia.

As reported in The Digest in June 2018, a closed-loop biorefinery could dramatically lower the cost of biofuels and related products. In this approach, the refinery produces the solvents it needs, rather than “importing” them. Scientists at the Joint BioEnergy Institute are developing a closed-loop biorefinery concept that uses waste lignin as a potential process solvent. How? They synthesized a new and renewable class of deep eutectic solvents. These solvents work well. When mixed with other liquids and used for biomass pretreatment, these solvents released sugar from grassy feedstocks for fuel and chemical production.

In the market

There are many different kinds of biosolvents already in the market. One of them already available in Europe, Middle East and Africa is Cargill’s Agri-Pure biosolvent. Agri-Pure is a vegetable oil-derived biosolvent that is non-toxic, biodegradable, food-contact safe, reduced fire risk, non-VOC designated, low odor, and compatible with most metals, plastics and rubbers. According to Cargill, it is a good alternative to the use of white spirits, kerosene, liquid paraffin and other low-to-medium viscosity hydrocarbon oils. It is also compatible and miscible with many chlorinated and oxygenated solvents, so that partial replacement of these solvents may also be possible in some cases.

Another one is the CytoSol BioSolvent which is derived from vegetable oil, animal fats, and recycled cooking oil (methyl esters) and is effective for dissolving and releasing weathered oil. It is a biodegradable shoreline cleaner to ‘Lift and Float’ oil from impacted marshes, mudflats and beaches and was consists of straight-chained aliphatic esters that boost populations of naturally occurring hydrocarbon-degrading bacteria at spill sites. In combination with oliophillic nutrients in the formulation and synergistic bioremediation technologies, the CytoSol accelerates the biodegradation of residual petroleum and ester hydrocarbons left on the shorelines or in water.

AstroBio Green Solvents are derived from agricultural crops rich in carbohydrates, such as corn, wheat and beets. Esters of lactic acids and further natural acids are used, as well as bioethanol and further alcohols made from fermentation and purification of carbohydrates. Their present European production of biosolvents uses just GMO-free sources.

The applications are wide randing for Vertec BioSolvents – from agriculture formulation of greener herbicides, pesticides, and growth enhancers to the formation of an environmentally friendly ink. Their biosolvents are also used for paint gun and line flush cleanings. They serve as effective high-solid, Hazardous Air Pollutant (HAP) free “green” coatings. In fact, a California company commercialized plastics recycling process using VertecBio Solvents.

And before you even ask if it’s really that good, an independent report prepared for the U.S. Airforce by NCI Information Systems Inc. ranked two bio-based solvents from Vertec Biosolvents Inc. among the best materials for paint line cleaning performance.

Vertec BioSolvents Inc. also achieved a major breakthrough in lactate ester technology. Lactate esters have always been highly effective, but minimally used due to strong characteristic odor. But Vertec discovered that blending lactate esters with certain specific alcohols can overcome the odor and tolerance issues that inhibited its use.

This technology breakthrough expands potential for further application of bio-based solvents as replacement for petrochemical solvents, according to Vertec.

Bottom Line

These are just a few of the biosolvents currently on the market – there are so many more out there already in production and being used in a wide variety of applications. But there is a story to tell with biosolvents – a move towards a less toxic and greener way while also improving performance and efficiency. It’s the little things that can make a big difference.