(491b) Dry Reforming Assisted Nonthermal Plasma Catalytic Reactor

Dry
reforming assisted nonthermal plasma catalytic reactor

Shaik
Mahammadunnisa, P. Manoj Kumar Reddy, B. Ramaraju, Ch.Subrahmanyam

Department
of Chemistry, IIT Hyderabad-502205, India

The negative effect of global
warming of carbon dioxide (CO₂) is well established and there is an
immediate need to develop large scale CO₂ utilization techniques. Catalytic
CO₂ reforming of natural gas also has drawbacks such as high
reaction temperature and clogging caused by coke formation. Hence, alternative
technologies for CO₂ utilization are much warranted [1]. In this
context, non-thermal plasma generated under ambient conditions seems to be the
best choice, where CO₂ can act as an oxidant due to the fact that
its deoxygenation proceeds rapidly in the absence of O₂. CO₂
reforming of aliphatic hydrocarbons, especially methane also contributes to the
co-processing of two potential global warming compounds [2].

The experimental set up used for
CO₂ reforming  consists of plasma
generation in a quartz tube of length 30 cm and diameter was 21 mm and
effective discharge area was 15 cm. Stainless steel rod was used as an inner electrode
and the outer electrode was Cu wire wound around the quartz tube. The discharge
gap was 3.5 mm. In order to understand the influence of catalyst, 500 mg NiO/Al₂O₃
was placed at the end of plasma zone. The AC voltage in the range 10 to 22 kV
at 100Hz was applied. The discharge power (W) of the DBD reactor was calculated
by V-Q Lissajous method [3]. Products were identified by using an online GC-2014
and confirmed with a GC-MS. The influence of various parameters like input
power, total feed flow rate, dilution and catalyst on the conversion and
product selectivity were studied.

Typical results indicated that
NiO catalyst partially reduced to Ni showed highest conversion and methane conversion
was always higher than that of CO₂. As seen from Fig. 2, increasing
voltage showed higher conversion and selectivity towards syngas (Fig. 2). At 22
kV and 11 W, selectivity to H₂ and CO was 30% and 55%, respectively
with plasma, whereas, plasma combining NiO catalyst increased the selectivity
to 55% and 65%. It was observed that partial reduction of NiO further improved
the conversion and selectivity.

1.     
Xinli Zhu, PeipeiHuo,
Yue-ping Zhang, Dang-guo Cheng, Chang-jun Liu, Applied Catalysis B:
Environmental 81 (2008) 132?140.

2.      Chang-junLiu , Gen-huiXu , Timing Wang, Fuel Processing Technology 58 
1999  119?134.