Silicoaluminophosphate molecular sieves as a hydrocarbon trap

Screening of different zeolites and silicoaluminophosphates for the retention of propene under cold start conditions

“…Finally, the synthesis of the silicoaluminophosphate molecular sieve SAPO-41 and SAPO-5 were carried out following the procedure described by Elangovan et al [12]. In a typical synthesis of SAPO-5, the synthesis mixture was prepared by slowly adding (during 3.5 h) of 6.71 g of (pseudo) Boehmite alumina (Sasol) in a phosphoric acid solution (11.53 g phosphoric acid (P85%) (Sigma-Aldrich) in 11.81 g water).…”

One-Dimensional Molecular Sieves for Hydrocarbon Cold Start Emission Control

“…The ''light-off'' temperature is considered to be the temperature at which 50% of the emissions are converted. A variety of methods have been proposed to improve cold start emission control, including electrical heating of the catalyst or gas entering the catalyst [1] and trapping hydrocarbons until the catalyst reaches light-off temperature [2][3][4][5][6], whereupon the hydrocarbons are released for oxidation.…”

Hydrocarbon Reformer Trap by Use of Transition Metal Oxide-Incorporated Beta Zeolites

“…Typically, the amount of adsorbed toluene was 0.11 cm 3 (STP) per gram of Fe-Al-beta. The amount of adsorbed HC on the trap materials relates closely to the micropore volume, decreasing with the decrease in volume caused by hydrothermal treatment for example [10,11]. The adsorption capacities of H-beta and Fe-Al-beta appear comparable, with the micropore volumes of those samples being 0.13 and 0.15 cm 3 per gram, respectively.…”

“…By use of SAPO, silicoaluminophosphate series zeolitic microporous materials, we have found that smaller exit pores resulted in better performance from the viewpoint of diffusion through the crystal, though the adsorption capacity was lower. On the other hand, larger pores were more effective from the viewpoint of adsorption amount [,though] the trapped HC eluted more quickly out of the particles [11]. Consequently, a mixture of micropores having different sizes in SSZ-33 is considered to demonstrate a unique HC holding capacity.…”