Clean Technology

Most Recent Inventions

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.

Industrial Streptomyces with Capability to Grow on Cheap and Abundant Cellulose

Building on their work, the researchers have developed an optimized set of enzymes useful to create Streptomyces with the capability to grow on cellulosic polysaccharide substrates. The method enables industrially relevant strains to grow on cellulose as the sole carbon source.

Using an engineered plasmid expression system derived from the ActE strain, the researchers transformed two commercial species (S. lividans and S. venezuelae) and showed that they were able to grow on filter paper as the sole carbon source. Other suitable host stains include S. coelicolor, S. griseus, S. clavuligerus, S. hygroscopicus, S. viridochromogenes and S. avermitilis.

Rechargeable Desalination Battery

UW–Madison researchers have designed a rechargeable desalination cell that can operate on seawater and is capable of performing a desalination/salination cycle with a net potential input as low as 0.2 volts. The cell comprises a sodium-storage electrode coupled to a chloride-storage electrode made of nanocrystalline bismuth foam.

The bismuth-based electrodes are able to store chloride ions in their bulk by oxidizing Bi to BiOCl in the presence of an oxygen source, such as water. Advantageously, BiOCl is insoluble in water over a wide pH range and inert against water oxidation. It also is stable over a wide range of anodic potentials. As a result, the new electrodes can be used for chloride removal in a variety of aqueous sources.

The BiOCl electrode can be converted back to a bismuth electrode by a reduction reaction, where the chloride ions are released into the electrolyte. This reverse reaction allows for the repeated use of the electrode for chloride storage/release via multiple chlorination/dechlorination cycles.

Perovskites for Stable, High Activity Solid Oxide Fuel Cell Cathodes and Related Technologies

Using high-throughput computing and informatics to screen thousands of candidates, UW–Madison researchers have identified doped perovskite compounds that exhibit both high catalytic activity and thermodynamic stability under ORR operating conditions. These improvements are believed to enable lower-temperature operation of SOFCs and improve device lifetime.

In total, approximately 1950 distinct perovskite compositions were simulated. The most active predicted compounds were found to contain alloys of transition metals and redox-inactive dopant elements (ex., Zr, Hf, Nb, Re and Ta) that can enhance stability.

Slippery Antifouling Surfaces with Health, Environmental and Consumer Applications

UW–Madison researchers have developed a new approach for fabricating and functionalizing SLIPS on objects of arbitrary shape, size and topology (e.g., inside a hollow tube, etc.). The new SLIPS have greater control over how fluids behave when they come in contact. For example, they can be designed with oil-free regions to immobilize fluid droplets and/or control how they slide across the surface.

The new SLIPS are antifouling to bacteria, fungi and mammalian cells, and may be used for the controlled release of antibiotics and to prevent thick liquids or dirt from building up on a surface. They are fabricated via the infusion of oils into reactive polymer multilayers.

Most Recent Patents

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.

Producing Linear Alpha Olefins from Biomass

UW–Madison researchers have developed a method for producing LAOs cheaply from biomass. In the process, an inexpensive solid acid catalyst is used in a reaction that converts the carboxylic acids and lactones present in the feedstock. The catalyst features Lewis acid catalytic sites and no precious metal components.