Dolomite is a double salt mineral, which consists of CaCO3 and MgCO3 that have different decarbonation temperatures. A particular modification is observed on the surface of mineral and the specific surface increased when dolomite was thermally treated at certain temperature. This investigation was carried out aiming at searching possibility of application of dolomite thermally treated at various temperatures for removing and recovering boron from aqueous solution. The confirmed best affinity adsorbent of boron is the heated dolomite at 750°C for 30 minutes. A series of experiments for adsorbing, and desorbing boron from a concentrated solution indicated the effectiveness of the thermally treated dolomite in terms of the adsorption capacity, which is similar or higher than the conventionally used adsorbents, such as activated carbon and fly ash. Thus, the results of this investigation suggested the adsorbent can effectively adsorb boron from drinking water or waste water, enabling the recovery of boron as new resource material.
Fuel cell hybrids are combination of energy conversion sub-systems—fuel cells and heat engines. Fuel cell hybrids are important for the future as they are currently the most efficient devices when converting chemical energy of methane from renewable fuels to electricity. While the perfect fuel cell would undergo no degradation, practical fuel cells, like batteries, will degrade. This paper is a study of fuel cell hybrids electrochemical performance when the fuel cell sub-system is undergoing degradation. In all cases, one can utilize the waste heat to improve overall efficiency through hybridization. Even degradation rates of 0.25 percent per 1000 hours, corresponding to 40,000 hour life, produce significant amounts of waste heat. Power loss is especially high at the cycle end-of-life. Hybridization utilizes waste heat and can be used if degradation occurs and long fuel cell life is expected. The common practice is to linearize degradation. Giving a linear representation to DR, however, gives a linear structure to the area specific resistance, ASR(t). Experimental evidence shows that ASR(t) is commonly an ohmic parabolic function. Degradation rate, DRavg(t), %/1000 hours varies throughout the life of the fuel cell for ohmic parabolic degradation behavior.