Carbon Dioxide Utilization - DNV

Figure 5. Specific energy consumption vs. Faradaic efficiency (FE)for various products. The thicker lines with data points indicateexperimental results achieved in various studies.Figure 6. The relationship among the key parameters in ERC processes.values for each parameter in a commercially viableelectrochemical process are also included in Figure 6,along with target areas for improvements. In addition,there are other important requirements, such as high onepassconversion rate and continuous operation.In general, higher current densities result in lower FE andshorter lifetimes because of competing reactions. Withlonger run times, FE tends to decrease (catalyst/cathodedegradation) and cell voltage increase, both of whichresult in greater power consumption. DNV has developednovel cathode and anode catalysts that reduce the totalcell voltage by almost 1 volt [26, 27]. Additionally, DNVhas designed a reactor that reduces the resistive lossesby another 2 volts, thus resulting in an overall decreasein the total cell voltage by about 60 %, compared withthe data published in the literature [27]. Furthermore,the long-term performance of the cathode catalyst hasbeen increased by at least 20 times over that reported inthe literature. This has mainly been achieved throughimprovements in the electrochemical cell design andoperational parameters. Fundamental studies performedby The Ohio State University, in collaboration with DNV,have improved our understanding of the cathode catalystdegradation mechanisms. This will enable furtheradvances in catalyst life. DNV has also identified lesscorrosive electrolytes that will reduce both capital andoperational expenditure.9