Clean Technology

Most Recent Inventions

Production of Medium-Chain Fatty Acids from Biorefinery Residue

UW–Madison researchers led by Profs. Daniel Noguera and Timothy Donohue have developed a method for converting unreacted chemical components in stillage to valuable medium-chain fatty acids, such as hexanoic and octanoic acids, using a mixture of microbes (e.g., anaerobic microbiome).

Operationally, a portion of the stillage stream is separated and fed to a bioreactor containing the mixture of microbes, which transforms a fraction of the stillage to MCFAs. The other fraction of the stillage can be sent on to the anaerobic digester to generate electricity (similar to existing biorefineries).

Enzymatic Depolymerization of Lignin

UW–Madison researchers provide the first demonstration of an in vitro enzymatic system that can recycle NAD+ and GSH while releasing aromatic monomers from natural and engineered lignin oligomers, as well as model compounds composed of similar chemical building blocks. Nearly 10 percent of beta-ether units were cleaved when the system was tested on actual lignin samples.

The relevant enzymes include dehydrogenases, β-etherases and glutathione lyases. In an exemplary version, the system uses the known LigD, LigN, LigE and LigF enzymes from Sphingobium sp. strain SYK-6. A newly discovered heterodimeric β-aryl etherase (BaeA) can be used in addition to or instead of LigE.

High Yield Method to Produce HMF from Fructose

UW–Madison researchers have discovered that a solvent system comprising water and a polar aprotic solvent (e.g., acetone) is ideally suited for converting C6 carbohydrates into HMF at reasonably low temperatures (such as 120°C), low acid concentration and at very high yields and efficiencies.

The C6 carbohydrate used in the method can be derived from any source including biomass (processed or unprocessed), cellulose and lignocellulosic sources, etc. The nature of the C6 carbohydrate is not critical to the method, although fructose is preferred.

Field Portable Smartphone Device for Water Quality Monitoring

A University of Wisconsin-Green Bay professor of chemistry has developed a portable, accurate, low cost, smartphone-based analytical device for the field-measurement and geographical mapping of environmentally relevant water quality parameters. In its current embodiment, the device is a colorimeter for measuring absorbance that includes a visible light source with onboard power, imaging filters, a sample cuvette, and a mounting mechanism for attachment to a smartphone or tablet. An accompanying app is used to record camera images of samples and convert them to numerical absorbance data for analysis. The app will be further developed to allow integration with an online ArcGIS platform for uploading and mapping the data.

Device to Monitor Airborne Silica for Enhanced Occupational Safety

Researchers at the University of Wisconsin-Eau Claire have designed a new device to rapidly quantify breathable, airborne silica. This device uses a novel adaption of a technique previously used almost exclusively for water quality analysis. To achieve this, it collects ambient air and uses specialized components to purify the air and collect particles of interest into an aqueous solution. Silica particles in solution then undergo chemical processes to create an acid that is subsequently bound to a light-emitting (chemiluminescent) molecule that can be detected and measured by light-sensitive electronics. This chemiluminescence-based strategy is simpler and likely more sensitive than a potential alternative strategy of absorbance, which is more cumbersome because it requires multiple components to provide a light source, reference cell, and a light detector. The current design of this device can fit comfortably on a table top for portability, and employers can use it without specialized laboratory experience. Preliminary studies suggest that this new device has a silica particle detection limit of approximately 20 µg/m3, appropriate for use towards compliance with the new OSHA personal exposure limit of 50 µg/m3. In addition, preliminary work also indicates that the device can make measurements in as quickly as 20 minutes, making it a much faster complement to the current analysis standards that take days to weeks. Overall, this new airborne silica detection device is a compelling answer to the challenge of rapidly and cost-effectively detecting life-threatening contaminants in occupational air environments.

Most Recent Patents

“Green” Triboelectric Power Boards Turn Footsteps into Electricity and More

UW–Madison researchers have developed the first TENG device built entirely from biodegradable and green materials. The two active layers comprise cellulose nanofibrils (CNFs) or wood fibers chemically treated to alter their electron affinity. CNFs and wood fibers are ideal because they have high surface areas, can be functionalized with a variety of chemical groups and can be formed into flexible and optically transparent films.

Zip-Lignin™ Assay: An Analysis and Validation Tool

The researchers have now developed the most sensitive assay to date for detecting and quantifying Zip-lignin monomers in plants. They modified an existing lignin assay known as DFRC (Derivatization Followed by Reductive Cleavage) that has been in use for almost a decade. They incorporated several new features to improve the sensitivity of the assay, including extended incubation periods and an additional purification step.

The modified DFRC assay is currently the only known technique capable of determining levels of monolignol ester conjugates in plant lignin.

Enhanced Biomass Digestion with Wood Wasp Bacteria

UW–Madison researchers have derived preparations from ActE secretions that highly degrade lignocellulose. The bacteria can be obtained from Sirex noctilio wasps and grown on a substrate containing mostly cellulose, hemicelluloses, xylan, wood or non-wood biomass, and chitin. The substrate may be pretreated for better results. The ActE are grown aerobically to maximize the secretion of both oxidative and hydrolytic enzymes capable of rapid deconstruction of matter. The secretions can be purified and added directly to biomass slurry.