Cookstove studies have reported pollutant concentrations (mainly PM 2.5 , black carbon and CO) without routinely associating it with the design and operating principles of the stoves. Extensive characterization of pollutants from cookstoves and the effect of different operating conditions are required for a better understanding of the mechanisms of pollutant formation. In this study, a forced draft (FD) and a natural draft (ND) gasification-based improved cookstove were tested under controlled conditions. Real-time pollutant concentrations, both particulate (PM 2.5 , lung-deposited surface area and particle number size distribution) and gaseous (CO, CO 2 and NO x), from these stoves using three types of fuel (applewood chips & chunks, cowdung cake and coal) along with different cookstove operating conditions (air flow rates and with or without a cooking pot) were measured and compared. The FD cookstove tended to exhibit higher concentrations of emissions compared to the ND cookstove. Increasing airflow through the FD stove decreased flame length and the residence time of VOCs inside the flame zone, which in turn increased pollutant concentrations. An optimum air flow producing the lowest particulate matter (PM) concentrations was established for the FD cookstove. The CO-CO 2 ratio, an indicator of combustion efficiency, demonstrated strong correlations with PM 2.5 (r = 0.857), particle geometric mean diameter (r = 0.900), and the total surface area concentration (r = 0.908) indicating that CO-CO 2 ratio may be used as a proxy for these PM metrics. Results reported in this study will facilitate further improvements in the design of future cookstoves.

Chemical looping is a promising combustion technology utilizing the cyclic oxidation and reduction of a metal oxide to transport oxygen for a variety of applications related to carbon capture and storage (CCS). The scalable manufacture of a suitable oxygen carrier is a pivotal aspect of this research field. This work surveys the experimental preparation of CuO and CuO/NiO on SiC and SiO2 substrates for chemical looping with oxygen uncoupling (CLOU) applications. A novel impregnation method that enhances the metal–support interaction to increase dispersion and reduce CuO sintering has been developed in this work. Particles prepared using this method, termed “selective adsorption wet coimpregnation”, exhibited agglomeration resistance and high reactivity over many regeneration cycles. CuO/NiO@SiO2 oxygen carrier (33 wt % CuO, 1 mol of Ni/99 mol of Cu) showed no signs of agglomeration up to 975 °C in fluidized bed testing, cycling between CuO and Cu2O. Thermogravimetric analysis showed no loss in oxygen transport capacity or decrease in kinetics over 100 cycles.