Methanol steam reforming over silica aerogel supported catalyst for hydrogen production


Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Kimya Mühendisliği Bölümü, Türkiye

Tezin Onay Tarihi: 2018

Tezin Dili: İngilizce

Öğrenci: PINAR DEĞİRMENCİOĞLU

Asıl Danışman (Eş Danışmanlı Tezler İçin): Naime Aslı Sezgi

Eş Danışman: Timur Doğu

Özet:

Our energy demand shows an increasing trend parallel to the increase in population. An important issue while we are meeting our energy need is that the source of energy should not pollute the environment. It is seen that hydrogen becomes a suitable choice as energy source when the fact that depletion of fossil fuels is considered. Hydrogen, which is not found in pure form in nature, is to be produced by some methods. In this study, hydrogen was produced from methanol steam reforming reaction. By doing so, maximum 3 moles of hydrogen can be produced per mole of alcohol. Type of the catalyst support is an important parameter that affects the performance of the catalyst during alcohol reforming reactions. A mesoporous catalyst support, silica aerogel, is synthesized by following sol-gel technique and after that convenient type of metal (Cu, Zn, etc.) was loaded into this support via wet impregnation method. Metal loaded catalysts are first calcined, then reduced and finally placed in reaction environment in order to obtain a long term stable catalyst which will provide obtaining hydrogen gas with very low side product content. It was seen that methanol conversion increased with an increase in calcination temperature, and the highest methanol converison (86.1%) is reached with the catalyst calcined up to 700°C, namely 10Cu-SA Air/Ar 700. The best result in methanol steam reforming at 280°C is obtained from 15Cu-SA Air/Ar 700 catalyst which provided 2.75 average hydrogen yield, 92.1% methanol conversion and 3.6% coke formation. Adsorbents such as huntite and hydrotalcite were used to capture the side product CO2, in methanol steam reforming reactions and the best result was obtained with hydrotalcite which captured CO2 for 55 minutes when mixed with 15Cu-SA Air/Ar 700 at 200°C in 1/15 weight base. It was seen that 15Cu-SA Air/Ar 700 was a stable and regenerable catalyst.