Clean Technology

Most Recent Inventions

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.

Organic Polymers with Ultra-Small Pores for Carbon Dioxide Separation, Capture, and Conversion

Researchers at the University of Wisconsin – Platteville have synthesized an array of chemically and thermally stable organic polymers comprised of ultra-small pores capable of separating out and capturing carbon dioxide molecules from a mixture of gases. These include phenazine linked polymers (PLPs), glyoxal‐derived polymers (GDPs), benzoxazole‐linked polymers (BOLPs), and benzothiazole‐linked polymers (BTLPs) with each having nitrogen-rich functionality to attract CO2. The single component adsorption isotherms demonstrated that the polymers have exceptionally high CO2 capture ability over CH4 and N2 with maximum adsorption selectivity of 35 times greater and 140 times greater, respectively, at 25°C. Such polymers have utility in the formation of membrane composites for use in membrane gas separation technology. Additionally, the researchers have been able to combine these polymers with silver metal resulting in the catalytic conversion of carbon dioxide molecules to useful chemical compounds.

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.

Modified Cyanobacteria for Competitive Sugar Production

UW–Madison researchers have developed strains of Synechococcus sp. Strain PCC 7002 with the highest reported glycogen or starch production rate of any cyanobacteria or algae. The strains are genetically modified to overexpress a glucose-1-phosphate adenylyltransferase.

Most Recent Patents

Boron- and Nitride-Containing Catalysts for Oxidative Dehydrogenation of Small Alkanes and Oxidative Coupling of Methane

UW–Madison researchers have developed improved ODH catalysts for converting short chain alkanes to desired olefins (e.g., propane to propene and ethene) with unprecedented selectivity (>90 percent).

The new catalysts contain boron and/or nitride and minimize unwanted byproducts including CO and CO2. They contain no precious metals, reduce the required temperature of the reaction and remain active for extended periods of time with no need for costly regenerative treatment.

In addition to driving ODH reactions, the new catalysts can be used to produce ethane or ethene via oxidative coupling of methane (OCM).

Modified Yeast with Enhanced Tolerance for GVL Biomass Solvent

UW–Madison researchers have developed a genetically modified strain of Saccharomyces cerevisiae that is more resistant to GVL toxicity and grows more than 1.5 times faster than wild yeast in the presence of GVL.

The researchers deleted two genes (Pad1p and Fdc1p) in the yeast that play a role in mediating GVL tolerance. The new strain is the first ethanol-producing yeast specifically tailored for GVL-based techniques.

Solar Cells for Reducing HMF to Valuable Platform Chemicals

UW–Madison researchers have developed a high yield method for reducing HMF to valuable furan alcohols including BHMF.

The new method uses electrochemical cells (ECs) or solar-powered photoelectrochemical cells (PECs) to drive the reduction reaction. The cells feature cost-effective catalytic electrodes made of silver film on copper. The reaction takes place at ambient temperature and pressure using water as the hydrogen source.

The process also can be used to produce linear ketones such as 5-MF (5-methylfurfural) using a zinc catalyst.