Biofuels production using starch over heterogeneous catalysts için kapak resmi
Biofuels production using starch over heterogeneous catalysts
Başlık:
Biofuels production using starch over heterogeneous catalysts
Yazar:
Uçaroğlu, Merve, author.
Yazar Ek Girişi:
Fiziksel Tanımlama:
ix, 45 leaves:+ 1 computer laser optical disc.
Özet:
In this study, the effect of acidity and acidic strength on the product distribution in the hydrolysis of starch was investigated on mixed oxide supported Ni catalysts prepared using different types of metal oxides with varying compositions and, the calcination temperatures. SiO2/Al2O3 (mass ratios of 30/70, 50/50, 70/30) and ZnO/TiO2 (mass ratios of 10/90, 30/70, 50/50) catalysts were synthesized using a sol-gel method. For all the ratios and metal oxide types, Ni weight loading was 1%, 5.5% and 10%. The calcination temperatures used for all the SiO2/Al2O3 catalysts were 500 oC, 700 oC and 900 oC. The calcination temperatures used for all the ZnO/TiO2 catalysts were 300 oC, 400 oC and 500 oC. The starch hydrolysis reaction was carried out at 90 oC for the reaction time of 24 h. The concentration of the products was determined using HPLC and acidity/acidic strength of the catalyst were measured using NH3-TPD. This study showed that the product distribution was affected by catalyst compositions and calcination temperatures that resulted varying total acidity and acidic strength. Unidentifiable saccharides, maltotriose, xylose, and glucose were produced during the hydrolysis of starch on all the SiO2/Al2O3 supported Ni catalysts while there were only unidentifiable saccharides on all the ZnO/TiO2 supported Ni catalysts. The products distribution was found to strongly dependent on the nature of the acid type; for instance, Al2(SO4)3 crystalline phase was more active than the acid type on ZnO and TiO2 anatase crystalline phases. In addition, the glucose yield increased on the large Al2(SO4)3 crystallite sizes, e.g. the catalyst having 42 nm of Al2(SO4)3 crystallite size gave ~15% glucose yield whereas that having 10.5 nm of Al2(SO4)3 crystallite size gave 0%. Besides, acidic strength was more important than total acidity for the same acid type. In fact, the lower the acidic strength, such as located at 150 oC, higher the glucose yield was obtained.
Yazar Ek Girişi:
Tek Biçim Eser Adı:
Thesis (Master)--İzmir Institute of Technology: Chemical Engineering.

İzmir Institute of Technology: Chemical Engineering--Thesis (Master).
Elektronik Erişim:
Access to Electronic Versiyon.
Ayırtma: Copies: