Performance of Ni-Mo Sulfated Nanozirconia Catalyst for Conversion of Waste Cooking Oil into Biofuel via Hydrocracking Process

The synthesis of the Ni-Mo sulfated zirconia (NiMo-SZ) catalyst and its application to convert waste cooking oil into biofuel was successfully conducted. The synthesis process was started with a sulfation process on the zirconia oxide (ZrO2) using 0.5, 1.0, and 1.5 M sulfuric acid (H2SO4) through wet impregnation to obtain sulfated zirconia (SZ). Solid SZ with the highest total acidity value was calcined at temperature 500, 550, 600, 650, and 700 °C. Solid SZ calcined with the optimum temperature was treated with Ni and Mo metals at 1%, 2%, and 3% (w/w) through a hydrothermal method. Pure ZrO2, SZ, and 1, 2, and 3 NiMo-SZ catalysts were used in the hydrocracking of used cooking oil into biofuel. The results showed that the 1.5 M SZ catalyst calcined at 500 °C had the highest acidity value of 3.8137 mmol/g. The 3-NiMo-SZ catalyst had the best activity valuing at 80.54%, while 1-NiMo-SZ produced the best selectivity in producing gasoline fraction until 73.93%.

Microstructure and Oxidation Resistance of Thermal Barrier Coatings with Different Ceramic Layer

Thermal barrier coatings are widely used for protection of gas turbine parts against high temperature oxidation and hot corrosion. In present work the microstructural assessment of TBCs produced by atmospheric plasma spray (APS) method was conducted. Three types of ceramic powders were used: magnesia- stabilized zirconia oxide (Metco 210), yttria stabilized zirconia oxide (YSZ -Metco 204) and fine-grained YSZ – Metco 6700. As a base material the Inconel 713 was used as well and CoNiCrAlY was plasma sprayed (APS) as a bond coat. The thickness of all ceramic layers was in range 80 – 110 μm. The elemental mapping of cross-section of magnesia-stabilized zirconia showed the presence of Mg, Zr and O in outer layer. In the YSZ ceramic layer the Y, Zr and O were observed during elemental mapping. The isothermal oxidation test was conducted at 1100 °C for 500 h in static laboratory air. On all samples the delamination and spallation of ceramic layers was observed. Chemical composition analysis of coatings showed the presence of two areas: the first one contained elements from bond coats: Ni, Cr, Al, Co and second area contained O, Cr Co and O that suggest the scale formation. The obtained results showed the total degradation of all ceramic layers as a result of internal stresses in bond-coat. Microscopic analysis showed the areas with complete degradation of bond coats and formation of thick oxides layer.

Catalytic ketonization of palmitic acid over a series of transition metal oxides supported on zirconia oxide-based catalysts

Catalyst screening and optimization of a series of ZrO2 supported metal oxides for ketonization of undiluted, neat palmitic acid.

Three-Dimensional Slurry Printing Technology in Ceramic and Metal Application

Vat photopolymerization is one of additive manufacturing and also known as photo-curable three-dimensional printing technology. It uses light energy with the proper wavelength to expose on the liquid photo-curable resin inducing the photopolymerization process and resulting in solidification layer-by-layer. The building method is classified into two ways: free-surface and constrained-surface. The advantage and disadvantage of both methods are described and analysed according to the different material property and requirement. The basic composition for photo-curable resin consists of photo-initiator and monomer. Adding powder into photo-curable resin makes the photo-curable slurry. Literatures report that high density powder such as zirconia oxide or Inconel 718 is suitable for free-surface building method because of poor suspension. However, the volume percentage in the slurry is less than 50% causing the higher shrinkage ratio and inaccuracy after sintering process. The coupling agent may increase the suspension of powder in slurry but experimental result shows that it still cannot improve the success rate in the constrained-surface building method. Therefore, this study proposes a combination method to overcome the difficulty of making high density ceramic or metal part. In addition, the sintering process is a key factor to obtain the high dense part with no crack occurrence and desirable microstructure. The optimized sintering parameters for zirconia oxide and Inconel 718 are also introduced.