The US Environmental Protection Agency (EPA) honored the six 2015 Presidential Green Chemistry Challenge Award winners at a ceremony in Washington, DC. EPA’s Office of Chemical Safety and Pollution Prevention sponsors the Presidential Green Chemistry Challenge Awards in partnership with the American Chemical Society Green Chemistry Institute and other members of the chemical community including industry, trade associations, academic institutions, and other government agencies.
For 2015, EPA announced a new award category for a green chemistry technology that has a “Specific Environmental Benefit: Climate Change.” The 2015 winners are Algenol; Lanzatech; Renmatix; Professor Eugene Y.-X. Chen of Colorado State University; Soltex; and Hybrid Coating Technologies.
Algenol, For Specific Environmental Benefit: Climate Change Award. Sustainable Production of Ethanol and Green Crude
Algenol is being recognized for developing a blue-green algae to produce ethanol and other fuels. The algae uses CO2 from air or industrial emitters with sunlight and saltwater to create fuel while reducing the carbon footprint, costs and water usage, with no reliance on food crops as feedstocks.
Algenol has developed technologies for the recombinant and classical genetic improvement of cyanobacteria (blue-green algae), leading to strains that divert more than 80% of the photosynthetically fixed carbon into ethanol without a decrease in overall photosynthetic yield. This has led to improved biofuel productivity, higher economic returns, minimal waste production, and a lower carbon footprint.
Algenol’s hybrid algae are grown in saltwater in proprietary photobioreactors (PBRs) which minimize heterotrophic contamination and reduce water use. Photosaturation is a common limiting feature in aquatic photosynthesis and occurs when the rate of photon absorption exceeds the rate that the algae can use the energy for product formation (i.e., carbon fixation), such that the energy of the excess photons is wasted through non-photosynthetic processes. Algenol’s vertical PBR system offers a productivity advantage over horizontal systems by delivering a more dilute irradiance over a greater surface area of the PBR, thereby limiting photosaturation.
Algenol has also developed proprietary downstream processes for energy-efficient recovery of fuel-grade ethanol. In collaboration with Pacific Northwest National Laboratory (PNNL), Algenol has applied hydrothermal liquefaction technology to convert the spent biomass into green crude. Algenol is also working with PNNL, National Renewable Energy Laboratory, and Georgia Tech on development of higher-value green chemical production concepts.
Algenol has demonstrated about 15–20 times the productivity of corn-based ethanol on a per acre basis. In the past five years, Algenol moved this technology from laboratory scale to pilot scale and is currently completing the construction and commissioning of a 2-acre facility as part of the IBR Project ($52 million project with a $25 million grant from the U.S. Department of Energy). The overall process reduces the carbon footprint relative to gasoline by 60–80% according to peer-reviewed published work from Georgia Tech.
A single 2,000-acre commercial Algenol module is the equivalent of planting 40 million trees or removing 36,000 cars from the road. Broad deployment of this technology, with its low-carbon footprint, can contribute to CO2 emission reduction targets and lower dependence on fossil fuel resources.
Lanzatech, For Greener Synthetic Pathways. LanzaTech Gas Fermentation Process
LanzaTech is being recognized for the development of a process that uses waste gas to produce fuels and chemicals, reducing companies’ carbon footprint. LanzaTech has partnered with Global Fortune 500 Companies and others to use this technology, including facilities that can each produce 100,000 gallons per year of ethanol, and a number of chemical ingredients for the manufacture of plastics. This technology is already a proven winner and has enormous potential for American industry.
Carbon gas streams are often byproducts of established processes. When they cannot be utilized efficiently they are wasted, normally through venting or flaring. The conversion of carbon monoxide-rich gases through synthetic chemical pathways, for example Fischer-Tropsch or methanol synthesis, requires that H2 be available in the synthesis gas. Waste industrial gases often do not contain H2 and therefore cannot be converted using conventional synthetic pathways. Gas fermentation technologies have also stalled because gas toxicity requires expensive microbe conditioning and leads to gas solubility limitations.
LanzaTech developed a method to utilize gas streams with a range of CO and H2 compositions to produce fuels such as ethanol and chemicals such as 2,3-butanediol at high selectivities and yields. While both CO/CO2 and H2 are utilized in the process, LanzaTech’s proprietary microbes are also able to consume H2-free CO-only gas streams, due to the operation of a highly efficient biological water-gas shift reaction occurring within the microbe.
The process is facilitated by the enzyme-catalyzed chemistry of the Wood-Ljungdahl pathway whereby CO2 and CO can be converted in a water-gas shift reaction catalyzed by carbon monoxide dehydrogenase (CODH). Through a series of intermediates, CO and CO2 are ultimately fixed as acetyl-CoA by the CODH/ACS complex.
The process is a highly efficient conversion of acetyl-CoA to ethanol, as this is actually linked to growth of the organism. LanzaTech has also manipulated the organism for high yields of specific products (e.g. the microbes can make a single enantiomer of 2,3-butanediol), eliminating the need to separate and find markets for co-products.
These microbes operate close to ambient temperature and atmospheric pressure and are tolerant to high levels of toxicity. LanzaTech has overcome the gas solubility limitations through proprietary bioreactors that increase volumetric mass transfer by creating more interfacial area per volume bubble size. This results in higher product yield and productivity.
Life cycle analysis studies performed in partnership with MTU, E4Tech, and Tsinghua University, China, have shown that the LanzaTech gas fermentation process can produce fuels from steel mill off-gases with GHG emissions that are 50-70% lower than those of fossil fuels. Particulate matter and NOx emissions are also reduced. LanzaTech’s gas fermentation simultaneously makes valuable fuels and/or chemicals while mitigating the environmental effects of waste and residual industrial emissions. LanzaTech has partnered with over 10 global Fortune 500 Companies across a variety of sectors, including chemicals companies, INVISTA and EVONIK.
Renmatix, For Small Business. The Plantrose Process: Supercritical Water as the Economic Enabler of Biobased Industry
Renmatix is being recognized for developing a process using supercritical water to more cost effectively break down plant material into sugars used as building blocks for renewable chemicals and fuels. This innovative low-cost process could result in a sizeable increase in the production of plant-based chemicals and fuels, and reduce the dependence on petroleum fuels.
Traditional sugar sources, such as corn and cane, are expensive feedstocks for producing relatively low-value, high-volume products such as fuels and chemicals. Unfortunately, the traditional second generation technologies (acid, enzymes, and solvents) that were designed to extract these low value cellulosic sugars lack the practical economics to even compete with first generation sugars, let alone traditional petrochemical sources.
In part, this is due to the capital expense of historical technologies such as mineral acids and enzymatic processes that hydrolyze cellulosic feedstocks. This reality has severely limited the market adoption and broad integration of cellulosics.
Renmatix’s Plantrose process, which uses supercritical water to deconstruct biomass, provides cost‐advantaged cellulosic sugars by using primarily water for conversion reactions. The two-step continuous process deconstructs a range of plant material into renewable feedstocks to produce separate streams of xylose and glucose. After sugar extraction, remaining lignin solids can be burned to supply the bulk of the heat energy required for the process (or utilized in higher-value applications like adhesives or thermoplastics).
In the first step, biomass and water are pumped together, heated, and fed into a fractionation reactor, where the hemicellulose is solubilized into a five-carbon sugar stream. In the second step, the cellulose and lignin that were filtered away from the initial sugar steam are pumped into the supercritical hydrolysis reactor.
In the reactor, water acts as both a solvent and catalyst, decrystalizing and dissolving the cellulose and hydrolyzing the cellulose polymers. The temperature and pressure of the supercritical water system can be adjusted for very specific reaction condition control, enabling the use of smaller continuous reactors for large-scale commercial production.
Renmatix’s technological innovation, the use of water-based chemistry instead of enzymes, and/or acids, provides a cleaner, faster, and lower-cost method for deconstructing biomass into cellulosic sugars. Those sugars become the building blocks for a multitude of renewable downstream technologies to serve significant biochemical market demand—and begin providing meaningful volumes of “plantrochemicals”, in lieu of the conventional petroleum-derived equivalents. Renmatix partners and customers will build their own biorefineries by licensing the Plantrose process to convert locally available biomass into cellulosic sugars, enabling profitable scale-up of biochemical, cellulosic ethanol, and advanced biofuels markets worldwide.
Professor Eugene Y.-X. Chen of Colorado State University, for Academic. Greener Condensation Reactions for Renewable Chemicals, Liquid Fuels, and Biodegradable Polymers
Professor Eugene Chen of Colorado State University is being recognized for developing a process that uses plant-based materials in the production of renewable chemicals and liquid fuels. This new technology is waste-free and metal-free. It offers significant potential for the production of renewable chemicals, fuels, and bioplastics that can be used in a wide range of safer industrial and consumer products.
In condensation reactions, as two molecules combine to form a larger molecule, small molecules split off. Because of the loss of this small molecule, such as water, hydrogen chloride, ethylene, methanol, or acetic acid, these reactions are intrinsically waste-generating. Additionally, condensation reactions are often mediated by metals.
For the production of jet or other transportation fuels, fine chemicals, and bioplastics, biomass platform chemicals, such as 5-hydroxymethylfurfural (HMF), need to be upgraded through the C‒C bond forming, condensation reaction into chain-extended, higher energy-density substances, such as 5,5'-dihydroxymethylfuroin (DHMF). The 12-carbon DHMF is a new bio-derived building block that can be catalytically transformed into renewable fine chemicals, polymeric materials, and oxygenated biodiesel or premium alkane jet fuels.
Direct HMF coupling is not possible through aldol self-condensation of HMF because it lacks a necessary hydrogen atom in the α-position to the carbonyl group. Existing alternative methods, such as metal-mediated cross-aldol condensation, have to use other enolizable petrochemicals. These methods also suffer from the unavoidable waste inherent in conventional condensation reactions. Professor Chen and his graduate student Dajiang (DJ) Liu developed a new condensation technology that uses an organic catalyst, such as an N-heterocyclic carbene (NHC), to reverse the polarity of the HMF carbonyl (umpolung), to enabling a solvent-free direct condensation coupling of HMF into DHMF with quantitative yield and 100% atom-economy.
Professor Chen and his postdoctoral fellow Dr. Miao Hong also developed a polycondensation method, called “Proton-Transfer Polymerization” (HTP), which uses an NHC catalyst to polymerize dimethacrylates uniquely into biodegradable polyesters with 100% atom-economy. The resulting unsaturated polyesters are of interest for producing tailor-made biodegradable polyester materials through post-functionalization and cross-linking.
The synthesis of such polyesters from dimethacrylates is not possible by a metal-based process, such as the Ru or Mo-mediated acyclic diene metathesis, because such methods are ineffective for polymerization of electron-deficient, conjugated or sterically demanding diolefins such as dimethacrylates. In contrast, existing methods polymerize dimethacrylates through non-condensation, polyaddition pathways into non-biodegradable polymethacrylates.
The new condensation technology not only offers two novel condensation synthetic pathways towards the HMF upgrading and polyester production from acrylic monomers, both processes of which are not possible by any existing technologies, it also exhibits important hallmarks of a green technology by being catalytic, metal-free and 100% atom-economical as well as solvent-free (for the HMF upgrading) or biodegradable (for the polyester production).
Soltex, For Greener Reaction Conditions. A Novel High Efficiency Process for the Manufacture of Highly Reactive Polyisobutylene Using a Fixed Bed Solid State Catalyst Reactor System
SOLTEX (Synthetic Oils and Lubricants of Texas) is being recognized for developing a new chemical reaction process that eliminates the use of water and reduces hazardous chemicals in the production of additives for lubricants and gasoline. If widely used, this technology has the potential to eliminate millions of gallons of wastewater per year and reduce the use of a hazardous chemical by 50%.
Polyisobutylene (PIB) is used in the production of dispersants and detergents for lubricants and gasolines. PIB is an isobutylene polymer containing one double bond per polymer molecule. In high-reactive PIB, the double bond is at or near the end of the polymer chain in a branched position making the product more reactive. When the double bond is located at internal positions in the backbone of the polymer, PIB is less reactive, creating low-reactive PIB.
Traditional processes to make high-reactive PIB use a liquid polymerization catalyst. The catalyst is continually fed to the reactor and mixed with isobutylene monomer. The liquid catalyst is toxic and corrosive, and requires special handling systems and procedures to avoid exposure and vapor release. As the reaction mixture leaves the reactor, the catalyst must be immediately neutralized to stop the reaction and separated. The separation process involves washing the neutralized catalyst complex from the reaction mixture with copious amounts of water to remove all catalyst residues. Trace amounts are corrosive to subsequent processing steps and detrimental to product quality and stability. Neutralized catalyst cannot be recycled. This process substantially increases plant capital investment, increases operating costs, and generates approximately as much wastewater as product.
Soltex’s new process is based on a novel solid catalyst composition using a fixed-bed reactor system. A solid catalyst, in the form of a bead or other convenient geometrical shapes and sizes, is packed into a vessel to form a stationary, completely contained bed. Isobutylene monomer is fed to the reactor at a controlled rate and passes over the solid catalyst allowing the polymerization to occur. The polymer mixture exits the reactor at the same controlled rate. This reactor effluent contains minimal catalyst residues, therefore no subsequent catalyst separation or water wash is required. The Soltex process, using this solid catalyst composition, produces high yields of high purity product with significantly lower catalyst usage. It is a simplified, highly efficient operation with substantially reduced capital investment, low operating and catalyst costs, and no water wash generation.
Hybrid Coating Technologies/Nanotech Industries, For Designing Greener Chemicals. Hybrid Non-Isocyanate Polyurethane/Green Polyurethane
Hybrid Coating Technologies/Nanotech Industries is being recognized for developing a safer, plant-based polyurethane for use on floors, furniture and in foam insulation. The technology eliminates the use of isocyanates, the number one cause of workplace asthma. This is already in production, is reducing VOCs and costs, and is safer for people and the environment.
Isocyanates are critical components used in conventional polyurethane products such as coatings and foam. However, exposure to isocyanates is known to cause skin and respiratory problems and prolonged exposure has been known to cause severe asthma and even death. Isocyanates are also toxic to wildlife. When burnt, isocyanates form toxic and corrosive fumes including nitrogen oxides and hydrogen cyanide. Due to these hazards, isocyanates are regulated by the EPA and other government agencies.
To address the health and environmental hazards associated with conventional polyurethanes, Hybrid Coating Technologies (HCT) has developed a hybrid non-isocyanate polyurethane (HNIPU), also called “Green Polyurethane.” HNIPU is formed from a reaction between mixture of mono/polycyclic carbonate and epoxy oligomers and aliphatic or cycloaliphatic polyamines with primary amino groups. The result is a crosslinked polymer with β-hydroxyurethane groups of different structure.
HCT developed a novel concept for generating new multifunctional modifiers for “cold” cure epoxy-amine compositions, namely hydroxyalkyl urethane modifiers (HUM), and subsequently developed HUMs based on renewable raw materials (vegetable oils), which are now used for SPF and UV-cured acrylic polymer based coatings. Utilizing HUM provides the cured composition with superior coating performance characteristics including pot life/drying times, strength-stress properties, bonding to a variety of substrates and appearance.
Other characteristics, such as weathering and chemical resistance, are also strengthened while HNIPU is not sensitive to moisture in the surrounding environment. HCT also developed a version of its epoxyamine hydroxyurethane grafted polymer that replaces corrosive low-molecular weight amines with less hazardous high-molecular weight amines. HNIPU is a safer chemical formulation for use in polyurethane and epoxy applications such as coatings and foam. It also has improved mechanical and chemical resistance properties, replaces up to 50% of its epoxy base with renewable resources (vegetable derived) and is cost competitive compared to other conventional polyurethane and epoxy products.
HCT is currently manufacturing coatings in California with a production capacity of 100,000 tons. Applicators using HNIPU coatings report cost savings between 30-60% due to the product’s improved safety profile and excellent properties. HCT expects to see similar benefits for applicators using its spray polyurethane foam once it becomes commercially available in the next 1-2 years.
During the 20 years of the program, EPA has received more than 1500 nominations and presented awards to 104 technologies. Winning technologies are responsible for annually reducing the use or generation of more than 826 million pounds of hazardous chemicals, saving 21 billion gallons of water, and eliminating 7.8 billion pounds of carbon dioxide equivalent releases to air.
An independent panel of technical experts convened by the American Chemical Society Green Chemistry Institute formally judged the 2015 submissions from among scores of nominated technologies and made recommendations to EPA for the 2015 winners. The 2015 awards event will be held in conjunction with the 2015 Green Chemistry and Engineering Conference.