A new double-skin facade system integrated with TiO_2 plates for decomposing BTEX

摘要

This study proposes a novel double-skin facade integrated with TiO2 plates (T-DSF) for decomposing ambient air Benzene, Toluene, Ethylbenzene, and O-xylenes (BTEX) by utilizing the photocatalytic oxidation technique under natural sunlight. The performance of photocatalytic decomposition on the TiO2 plates was quantitatively compared using the predicted age of air and the amount of BTEX processed. Eighteen cases, i.e., 3 placement strategies of TiO2 plates by 6 airflow gap sizes, were evaluated using a validated computational fluid dynamics (CFD) model to design an optimal T-DSF. The study reveals that the designed T-DSF with 3-m wall height, 1-m wall width, 0.3-m cavity depth, and 0.1-m inlet and outlet height, in which the TiO2 plates are staggered on the external and internal glasses with a 0.02-m airflow gap, can clean about 77 m(3)/day of ambient air with 20 ppb BTEX (annual average) in Boulder, CO. The sensitivity analysis of solar radiation intensity was studied, which indicates that this system has a stable performance for decomposing BTEX under different solar radiations. Furthermore, the potential impact of particulate matter from ambient air on the photocatalytic oxidation performance was investigated, which was neglectable. This study presents a promising and passive design that can effectively treat BTEX in the atmosphere by taking advantage of UV radiation in natural sunlight and solar-driven natural convection. The concept can be applied in other ventilated cavity wall systems such as the Trombe wall while the key parameters need further fine-tuning.