Combination of Nonthermal Plasma and Low Temperature-C₃H₈-Selective Catalytic Reduction over Co-In/H-beta Catalyst for Nitric Oxide Abatement

Abstract

Nitric oxide (NO x ) abatement by a two-stage system composed of nonthermal plasma (NTP) followed by the selective catalytic reduction with C 3 H 8 (C 3 H 8 -SCR) over the Co-In=H-beta catalyst was investigated at a relativity low temperature range from 548 to 598 K. The combination system shows better synergy at low temperature. Optimum active temperature of Co-In=H-beta in the complex system is shifted from 648 to 598 K compared with that in C 3 H 8 -SCR. The highest NO x conversion is over 98%. In contrast to treatment by the NTP, the two-stage system converts mostly NO to nitrogen; without NO 2 , nitrogen-containing and organic components formed. The synergetic effect of the combination system is enhanced with the C 3 H 8 concentration and O 2 content.

Promotion of Nonthermal Plasma on the SO2 and H2O Tolerance of Co–In/Zeolites for the Catalytic Reduction of NO x by C3H8 at Low Temperature

“…For Co-In/H-Beta and Co-In/H-USY, the synergetic effect showed at temperatures from 548 to 623 K and from 523 to 573 K, respectively. According to our and other studies [9,16,24], the NO 2 formed through NO oxidation in the plasma is more susceptible to HC-SCR at low temperatures. In the HC-SCR reaction, the formation of NO 2 is the first important step [25][26][27], and subsequently the resulting NO 2 reacts with hydrocarbon-derived species to form N 2 [28] or the key intermediate species (e.g.…”

“…The detailed setup of the PF-C 3 H 8 -SCR hybrid system, which consists of a dielectric barrier discharge (DBD) plasma reactor and a fixed-bed catalytic microreactor, was described in our previous paper [9]. Approximately 3 mL of catalyst powder (weight: 1.8051 g Co-In/H-(Beta/USY), 1.8186 g Co-In/H-Beta, and 1.7902 g Co-In/H-USY) was held on a quartz frit at the center of the SCR reactor.…”

“…The long-term thermal stability [4], loaded states of Co [5], effects of Co loading and precursor [6], preparation method [7], and reaction mechanism [8] have been widely investigated for HC-SCR on Co/Beta, especially for C 3 H 8 -SCR [3][4][5][6][7]. To improve the stability and activity of Co/zeolites in HC-SCR, many studies have focused on the modification of Co/zeolites by adding indium, such as Co-In/Beta [9], Co-In/ZSM-5 [10], CoIn/HMCM-49 [11], and Co-In/ferrierite [12]. Interestingly, Zhang et al [13] found that Co loaded on a composite of zeolites (Beta/Y) showed higher activity than Co/Beta in CH 4 -SCR because of the stronger adsorption of NO and NO 2 on Co-exchanged Beta/Y catalyst.…”

“…Effect of temperatures on R of PF-C 3 H 8 -SCR hybrid system DBD is the NO x conversion of DBD reactor in the input voltage of 34 kV at room temperature[9] …”

In Situ Regeneration and Deactivation of Co-Zn/H-Beta Catalysts in Catalytic Reduction of NOx with Propane

“…Beta zeolite with an atomic ratio Si/Al = 25 was purchased commercially in H-form from Nankai University (Tianjin, China). Co-Zn/H-Beta catalysts were synthesized according to the method described elsewhere [40], using Co(NO 3 ) 2 and Zn(NO 3 ) 2 as precursors. All the chemicals were purchased from Macklin Inc. (Shanghai, China).…”