Materials Technologies in Renewable Energies

Biofuels, such as ethanol, butanol, and biodiesel, are being pursued aggressively because they offset some of CO2 emitted as well as reduce dependence on fossil oil. A significant growth in biofuels will depend on pipelines for safe, reliable and cost-effective transportation solutions. The materials compatibility issues with the transportation and storage of biofuels include, for example, stress corrosion cracking of steel in ethanol and the compatibility of ethanol and biodiesel with polymers used in seals, gaskets and coatings. DNV GL Research is actively involved in developing methods to improve materials compatibility, guidelines on safe operations, and techniques to remotely monitor corrosion/cracking of steel.

CO2 Utilization

Carbon dioxide is a ubiquitous by-product of fossil-fuel using industrial (e.g., power plants using coal or natural gas) and transportation (e.g., automotive, shipping and train) processes, but also a natural product emitted from industrial biochemical processes (e.g., fermentation of biomass to ethanol).  While the scientific and political debate about its role as a greenhouse gas contributing to rising global temperatures is on-going, strategies for CO2 mitigation need to be researched and developed.  There are essentially three strategies to reduce the accumulation of CO2 in the atmosphere: reduce emissions by the use of energy efficient technologies and non-carbon fuels, long-term removal of CO2 by storing it in stable geological media, and utilizing/converting the CO2 into useful products that will otherwise require carbon sources. It is likely that all three strategies will be employed for the world to meet meaningful CO2 reduction for future generations.

CO2 utilization technologies have the potential for immediate benefits to many industries, both to reduce CO2 footprint and gain some return on investment through product sales. Furthermore, utilizing CO2 as a feed stock reduces the use of hydrocarbon feed stocks for many chemicals. DNV GL has been involved in the assessment of various CO2 utilization/conversion technologies and in the in-depth development of the electrochemical technology. The findings of our research program thus far include the following:

• There is no one universally applicable pathway for CO2 conversion. Depending on the industry, location, and other constraints, one or more technologies will fit better than others.

• We believe that several different technologies may be used together to maximize CO2 utilization and return on investment. In this regard, CO2 utilization is very much like an integrated refinery that makes several products using a complex, interwoven process scheme. Rather than one entity developing all the required technological components, it is necessary to integrate the "best of class" of several technologies.

• Process modelling and value chain analysis are essential in setting targets for research, comparing different processes, and in scale-up.

• Electrochemical conversion offers many niche applications because it is modular, can be operated at ambient temperatures, may be used to make a variety of end products, and occupies a relatively small spatial footprint.

Our research is currently developing electrochemical conversion of CO2 to formic acid.   Formic acid is in demand and can also be used as chemical feedstock, steel pickling, antibacterial agents, energy storage medium, and deicing solutions.  It is also being used as feedstock for electrofuels processes. Other CO2 conversion products include carbon monoxide, methanol, and methane.

Project Objectives

The purpose of the work is to develop chemical conversion processes for CO2 to renewable.

• Leverage our expertise in materials, electrochemistry, process design, catalysis to develop chemical conversion technology which shows good techno-economic characteristics. 

• Be a technology leader in a developing field – CCU.  DNV GL foresees that CCU will become a key part of the solution to CO2 reduction.  By providing ourexpertise in technology development, we can ultimately leverage DNV GL core service businesses.

• Successful scale-up of the technology requires knowledge of the full Value Chain.  That is, renewable power costs and ancillary services, CO2 capture technology, chemical conversion including separations and purification of the product, and markets for the final products.  We have constructed and incorporated of a CO2 value chain model into development process to ensure economic feasibility.  

• Develop partnerships within the chemical process industry to bring CO2 utilization to commercial realization.

Energy Harvesting Materials

Energy harvesting generally refers to the capture of power or energy that might be considered “ambient”. Solid state or semiconductor energy harvesting materials provide low weight, small footprints, and readily available electronic integration with data collection systems for some applications. DNV GL R & I is investigating the use of such energy harvesting devices for sensors and applications where non-carbon energy sources are difficult to obtain.

Battery Life eXTension

Battery Life Extension, is a tool that DNV GL has developed based on extensive testing databases to size, predict degradation, and virtually test battery packs. DNV GL is presently using modeling to extend the operational limits of batteries, and validate the life extension and safe operation of batteries in a variety of applications. There are presently two main initiatives in the project, both of which are in collaboration with external partners and funding organizations:

In the US, DNV GL has partnered with companies to examine the deployment of a novel gas sensor that detects battery off gas. This will first be demonstrated on new batteries, and the lessons learned will be applied to second-hand batteries to demonstrate the viability of a “second life” of batteries. The life extension limits and model parameters will be validated along with the sensor in the deployment and demonstration in a Community Energy Storage (CES) platform. The underlying hypothesis of the project is that two factors limit the performance and revenue potential of battery-based energy systems: first, conservative estimation of the SOC limits and C-rates minimizes potential stresses on the battery but inhibits its maximum performance; second, retirement of batteries under the assumption that their remaining capacity has no value is premature. The project aims to use battery life prediction modeling and sensor monitoring to identify scenarios where the limits of battery operation can be pushed so as to extract greater performance without adversely affecting the net lifetime throughput. The sensor validates these limits and the model predicts performance with the newly established limits. It is presumed that sensor signals will provide early warning of battery stress prior to failure conditions, such that the performance envelope can be more accurately measured. In addition the project will demonstrate the implementation of second-hand batteries into a CES system to validate the remaining capacity of batteries and test their viability using the modeling and sensor approach.

In Europe, DNV GL is partnered with a mobility company to examine the use of batteries in second-hand applications, as well as new mobility markets such as hybrid ships. Projects in these areas span issues associated with rural electrification of transportation, implementing high power and high energy density batteries in ships such as tugboats and ferries, as well as using second-hand batteries to enable affordable microgrids.

The viability of second-hand batteries is greatly dependent on their intended application and the prior stresses that the batteries have experienced. DNV GL has found that if a battery is to double its revenue over its lifetime, it may be possible to pair the battery with applications where high revenue is earned for its energy throughput with only a 20-30% of its service life. This hypothesis is being tested with the programs described above.

The BXT program ties into existing DNV GL KEMA activities related to energy storage and compliments qualification and validation of battery-based energy storage systems.