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Overview
Diversified Energy Corporation (DEC) and North Carolina State University (NCSU) have developed a patent-pending technology for converting oils derived from any triglyceride feedstock (like agriculture crops, animal fats, algae, energy crops, waste greases, etc.) to high-value biofuels. The technology, termed Centia™ (a derivation of "green power" in Latin), integrates a sequence of four steps as shown in Figure 1 to produce biogasoline, Jet A-1/JP-8 (jet fuel), and renewable diesel. Unlike ethanol and transesterification-based biodiesel, the biofuels produced from Centia™ will replicate the chemical structure of their petroleum-derived counterparts, therefore enhancing performance and working seamlessly with existing distribution infrastructures, storage systems, and engines. The process is also differentiated from hytrotreating techniques that must rely on excessive amounts of hydrogen for deoxygenation. All of the process steps are either extensions of existing commercial practices or are based on recent technology demonstrations by DEC and NCSU.
Feedstock costs can often contribute as much as 80% to the cost of producing biofuels. For this reason, a key attribute of Centia™ is its ability to utilize a wide variety of inputs. This provides the owner of a biofuels plant the flexibility to use the most attractive feedstock available. Centia™ can utilize oils from crops being used today for the manufacture of biodiesel - like soybean, canola, palm, and jatropha, among others - as well as up-and-coming feedstocks like algal oils. Lastly, Centia™ can use oils from sources that are generally considered lower in value, such as waste greases and animal fats (e.g., inedible beef tallow, hog lard, and chicken grease). In fact, the higher the free fatty acid (FFA) content of the feedstock, the better for the process. The ability of Centia™ to use any triglyceride feedstock is therefore a key process discriminator.
Centia™ also provides flexibility in the type of biofuel produced. One excellent target market is the aviation industry because of its economic sensitivity to crude oil prices and the current lack of bio-based fuel alternatives. Fuel costs have recently put enormous pressure on gross margins, driving prices upward and ultimately hitting the consumer. The U.S. Air Force has stated that for every $10/barrel increase in crude oil, the impact is $600M in fuel expenses.1 Reactions from the commercial aviation industry, U.S. and foreign governments, and the military have led to calls for increased investments in alternative aviation fuels. Yet creating biofuels for aviation use is technically challenging. Jet fuels must withstand the harsh operating environment of aircraft - high energy densities, robust cold-flow properties, and stringent kinetic and combustion characteristics represent just a few of the unique properties required for Jet A-1/JP-8.
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| Figure 1: 4-Step Centia™ Biofuels Production Process |
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Centia™ has been specifically tailored to produce a fuel that is compliant to ASTM and Mil-Specs, and to do so in a manner that is highly efficient, affordable, and scalable to commercial volumes. The market potential is enormous, with the world consuming approximately 73 billion gpy of jet fuel and the U.S. accounting for roughly one-third of that demand.
In addition to biojet fuel, since the Centia™ process produces n-alkanes (the building block of fuels) in Step #2, these normal paraffins can be cracked and reformed differently in Step #3 to create other biofuels. A high cetane renewable diesel can be produced to address the cold weather, oxidation, and degradation problems experienced by traditional biodiesel (fatty acid methyl ester products). Alternatively, the n-alkanes can be processed to produce a biogasoline. This high-octane biogasoline would be chemically similar to petroleum derived gasoline, therefore being compatible with existing distribution systems, fueling infrastructure, and gasoline vehicle engines. This output flexibility ultimately translates into lower risks and enhanced economics for owners and operators of Centia™ biofuel plants.
Funding from NCSU, DEC, and grants has been used for a variety of lab-scale demonstrations of the technology. As examples show in Figure 2, tests have demonstrated the fundamental reactions in each of the process steps: (Step #1) hydrolysis using a 10 L/hr counterflow system and showing a 98% conversion efficiency, (Step #2) decarboxylation of a variety of FFA inputs showing in excess of 98% conversion efficiencies, (Step #3) isomerization and cracking, and (Step #4) fabrication and demonstration of a 90k Btu/hr glycerol burner. As an example of produced results, Figure 3 shows the cracking of n-alkanes into the carbon numbers required to match petroleum-derived unleaded gasoline.
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| Figure 2: Examples of Development Work Completed to Date |
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| Figure 3: Biogasoline Results Closely Align to Traditional Unleaded Gasoline Carbon Number Distribution |
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Key Attributes and Competitive Differentiation
Centia™ offers a number of benefits that distinguish it from traditional biofuels like biodiesel and ethanol, as well as new processes being introduced such as hydrotreating-based approaches, enzymatic systems, pyrolysis, gasification and Fischer-Tropsch, among others. These include:
- Feedstock Flexibility - the first Centia™ step is designed to accommodate any triglyceride feedstock. As such, the process has the flexibility to accommodate oils deemed the most available and cost-effective in that local region. Oils from agriculture crops, animal fats, algae, energy crops, waste greases, among others, are all acceptable with only operational modifications required to the process.
- Fuel Output Flexibility - the third Centia™ step produces fuels capable of meeting strict aviation specifications (e.g., Jet A-1/JP-8), solving cold weather and other issues associated with transesterification-based biodiesel, or being distributed and utilized in vehicles as a direct substitute to petroleum-derived unleaded gasoline.
- Little Net Hydrogen Consumption, No Methanol Use - Centia™ is not a traditional hydrotreating process where hydrogen is used to remove oxygen molecules during deoxygenation (to achieve certain energy densities). Instead, the process using a catalytic decarboxylation route to perform the same function. Centia™ plants will therefore not have to be installed near massive hydrogen production facilities - and since hydrogen generally comes from natural gas, this enhances the renewable footprint of the technology. Lastly, unlike traditional biodiesel production, no fossil fuel alcohols like methanol are required in the process.
- Direct Green Aromatics Production - Centia™ can produce aromatics for jet fuel and biogasoline directly in the renewable process, thus not requiring it to be added afterwards from a fossil fuel source.
- High Efficiency - the process is expected to deliver an end-to-end energy conversion efficiency of greater than 85%, a mass conversion efficiency in excess of 75%, and utilize roughly one-half the external energy of other conventional biofuel processes. In fact, utilization of the glycerol through the burner provides almost all of the energy required for process heating. This translates into higher yields and lower costs, an imperative for commercial viability and broad market adoption.
- Scalability - Centia's flexibility and low use of hydrogen allows for the system to be economically scalable for both small/distributed applications and larger facilities (20+ million gpy). Building 1 - 5 million gpy facilities close to the sources of feedstock and fuel distribution nodes is clearly an attractive and innovative offering to the market.
- Affordability - preliminary analysis shows biofuels could be produced at production costs ($/gallon) competitive with, if not lower than, traditional biofuels plants.
Path Forward
Two patents with 68 claims have been filed for the technology. DEC has licensed the technology from NCSU on an exclusive worldwide basis. While lab-scale testing has validated the science and produced encouraging results, the next prudent step is a fully integrated, end-to-end engineering model at approximately 10 - 20 liters/hour in scale. This 18-month demonstration at NCSU would showcase the production of multiple fuels from a variety of sources and characterize the quality and composition of those fuels in engine tests. In addition, the effort would be used to mitigate remaining technical risks associated with catalyst lifetime and continuous architecture designs. A team of five supporting companies have been identified, shown in Figure 4, to support the engineering model development and prepare for the introduction of commercial systems. DEC is seeking investors and strategic partners to support these efforts going forward.
Company Profiles
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| Figure 4: Centia™ Project Team |
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- North Carolina State University -
A nationally recognized leader in science and technology with historic strengths in agriculture and engineering, North Carolina State University (NCSU, www.ncsu.edu) provides a high-quality education in the humanities and social sciences, design, education, life sciences, management, natural resources, physical and mathematical sciences, textiles and veterinary medicine. Whether educating students for the 21st century, improving lives through life-altering research, or partnering with communities, business, and government to create jobs, NC State's commitment to innovation creates a culture of excellence that spreads to every facet of the university and affects people's lives in relevant, powerful ways.
NC State's Office of Technology Transfer manages the University's patent and technology portfolio, currently consisting of 552 U.S. Patents and approximately 1600 proprietary technologies. Forming partnerships with innovative companies such as Diversified Energy fulfills NC State's mission of getting academic discovery to the market for the greater public good. The university has spun-out over 50 companies based on technologies developed at the institution.
- BASF -
As the world's leading provider of catalysts to the biodiesel industry, BASF (www.basf.com) brings expertise in the practical issues of designing, scaling and O&M of catalysts in commercial applications. They also are the world's leader in hydrogenation catalysts, which is directly applicable to this effort.
- Lauren Engineers and Constructors -
A design and build engineering company, Lauren (www.laurenec.com) offers over 20 years experience in energy-related projects. They specialize in conducting early design trades to enhance the long-term performance, costs, and O&M of plants.
- Southwest Research Institute -
Southwest Research Institute (www.swri.edu) provides over 50 years experience in qualifying aviations fuels and led the qualification of the only synthetic fuel approved for aviation use.
- Turner Engineering -
Turner Engineering brings hands-on experience in fabricating biofuels facilities.
- Chambers Process Engineering -
CPE (www.cpeng.net) delivers responsive and customized process engineering to the team, with specialization in high-pressure/temperature equipment.
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