An experimental study of solar cooker performance with thermal concentrator system by spot Fresnel lens

This research was conducted to find out the influence of the use of a catalyst (zeolite) against kinetic rate results of tar pyrolysis of sawdust mahogany. research process undertaken experimentally with temperature 523K and 873K on the heating rate 673 K/hour. pyrolysis is done for 3 hours with wood powder particle size 0,5 – 1 mm. before use activated zeolite in advance by means of heated at a temperature of 400 °c for 1 hour. the results showed the value of kinetic rate tar with zeolites greater than without zeolites , where the value of the kinetic rate equation obtained i.e. 𝑘 = 185,49. 𝑒 −2779/𝑇 (heating rate 673 K/hour without zeolite) and 𝑘 = 93,037. 𝑒 (heating rate 673 K/hour with zeolite). The results of the validation shows the value addition in the calculation of the volume is already approaching the actual value.

The utilization of biopolymers for energy applications continues to attract researchers, due to the unique properties of biopolymers that are easily modified, such as cassava starch (CS) biopolymer that has hydroxyl molecular chains. However, the brittle, and non-waterproof nature of starch films is an obstacle to their use in triboelectric nanogenerator (TENG) solid-solid films. This study aims to improve the physicochemical properties of cassava starch films by modifying them into nanocomposite films. The nanocomposite film was made from 70:30 CS/polyvinyl alcohol (PVA) composite and variation of TiO2 nanoparticles addition using solvent casting method. The results showed that the mechanical properties of cassava starch film increased with the addition of PVA. Meanwhile, the addition of TiO2 above 1 wt % of the mechanical properties of the film tends to decrease. The film has low wettability properties with a contact angle of 83.6°. The performance of the nanocomposite film as a Rotary disc freestanding film (RDF-TENG) produces 4.4-fold the output voltage and 2.8-fold the current compared to the film without TiO2. This is a new finding that the CS/PVA-TiO2 nanocomposite film has the potential for TENG films in high-humidity environmental conditions