Production of renewable diesel from Jatropha curcas oil via pyrolytic-deoxygenation over various multi-wall carbon nanotube-based catalysts

Jatropha curcas is a highly toxic plant that produces seed containing viscous oil with productivity (2 ton/ha), it grows in tropical and sub-tropical regions and offer greater adaptability to a wide range of climatic and soil conditions. Its oils have been noted as an important alternative to produce green diesel via deoxygenation reaction. This study, deoxygenation of jatropha curcas oil (JCO) was carried out over NiO–Fe2O3 and NiO–ZnO catalysts that supported onto multi-walled carbon nanotube (MWCNT). It had found that high Fe and Zn dosages were ineffective in deoxygenation and greatest activity was observed on NiO(20) Fe2O3(5)/MWCNT catalyst. Structure-activity correlations revealed that low metal loading, large density of weak + medium acidic sites and strong basic sites play key role in enhancing the catalytic activities and n-(C15+C17) selectivity. Comparing carbon nanostructures and carbon micron size supported NiO-Fe2O3 revealed that green diesel obtained from NiO–Fe2O3/MWCNT catalysed deoxygenation had the highest heating value and the lowest amounts of oxygen content. Thereby, it confirmed the importance of carbon nanostructure as the catalyst support in improving the diesel quality. Considering the high reusability of NiO-Fe2O3/MWCNT (6 consecutive runs) and superior green diesel properties (flash point, cloud properties and cetane index) demonstrated the NiO–Fe2O3/MWCNT catalyst offers great option in producing excellent properties of green diesel for energy sector

A promoter effect on hydrodeoxygenation reactions of oleic acid by zeolite beta catalysts

In this study, various metal-modified zeolite beta-based catalysts such as La(10)zeo(90), Co(10)zeo(90), Fe(10)zeo(90), Mg(10)zeo(90), Mn(10)zeo(90) and Zn(10)zeo(90) were investigated in the hydrodeoxygenation (HDO) of oleic acid (OA) to produce renewable diesel. The La(10)zeo(90) catalyst showed a conversion of OA up to 99 % with 83 % C15 and C17 selectivity after the reaction at 350 ◦C for 2 h under 4 MPa H2 pressure. The superior activity of La(10)zeo(90) was attributed to the synergistic interaction between La-Si-Al, a sufficient amount of weak+ medium acid sites and excellent textural properties (large pore diameter). Larger pore diameter of La(10)zeo(90) is highly desirable as it will generate greater diffusion of bulky molecules, thereby improving the accessibility of the reactant and hence excellent catalytic activity. The vacuum distillation was used to purify the crude liquid product (CLP), producing high-quality diesel fractions mainly comprising C14, C15, and C17 fractions

Hematite microcube decorated tio2 nanorods as heterojunction photocatalyst with in-situ carbon doping derived from polysaccharides bio-templates hydrothermal carbonization

The novel in-situ formation of a heterojunction photocatalyst consisting of C-doped TiO2 nanorods decorated on the surface of C-doped α-Fe2O3 microcubes was successfully achieved using a one-pot hydrothermal carbonization synthesis. In this work, the treated kapok fibers (t-KF) used as a polysaccharide bio-template provided a dual function for crystal growth control and in-situ carbon doping of the heterojunction photocatalyst. It was found that the α-Fe2O3 precursor concentration plays an essential role in the unique and well-developed C-doped TiO2/α-Fe2O3 heterojunction formation. Assessment of photocatalytic activity of all samples indicated that the sample prepared with 0.25 M of α-Fe2O3 precursor concentration (BT-TF-0.25) exhibited the most efficient bisphenol A photodegradation in aqueous solution. The highest photocatalytic activity of BT-TF-0.25 under simulated solar irradiation was mainly associated with C-doping and favorable heterojunction formation between C-doped TiO2 and C-doped α-Fe2O3. Excellent charge carrier and separation were confirmed from the photocurrent response and photoluminescence spectroscopy analysis. Overall, this study is expected to contribute to the development of more efficient visible light active heterojunction photocatalyst systems, as well as demonstrating the versatility of polysaccharide materials as a green and low-cost bio-templates

Chemoselective decarboxylation of ceiba oil to diesel-range alkanes over a red mud based catalyst under H2-free conditions

Concerns over global greenhouse gas emissions such as COx and NOx as well as the depletion of petroleum fossil resources have motivated humankind to seek an alternative energy source known as green diesel. In this study, green diesel was produced via a deoxygenation (DO) reaction of ceiba oil under a H2-free atmosphere over Ni modified red mud-based catalysts, which have been synthesized via a precipitation – deep-deposition assisted autoclave method. The obtained catalyst was further characterized by XRF, XRD, BET, FTIR, TPD-NH3, FESEM, and TGA. Based on the catalytic activity test, all Ni/RMOx catalysts facilitated greater DO activity by yielding 83–86% hydrocarbon yield and 70–85% saturated diesel n-(C15 + C17) selectivity. Ni/RMO3 was the best catalyst for deoxygenizing the ceiba oil owing to the existence of a high acidic strength (12717.3 μmol g−1) and synergistic interaction between Fe–O and Ni–O species, thereby producing the highest hydrocarbon yield (86%) and n-(C15 + C17) selectivity (85%). According to the reusability study, the Ni/RMO3 could be reused for up to six consecutive runs with hydrocarbon yields ranging from 53% to 83% and n-(C15 + C17) selectivity ranging from 62% to 83%

Bio-inspired hierarchical hetero-architectures of in-situ C-doped g-C3N4 grafted on C, N co-doped ZnO micro-flowers with booming solar photocatalytic activity

The in-situ hierarchical heterojunction photocatalyst consists of C-doped g-C3N4 (CCN) grafted on the C, N co-doped ZnO were successfully realized via simple bio-template hydrothermal approach. The resultants hierarchical heterojunction photocatalyst exhibited excellent UV to the near infrared absorption capability. The electrochemical analysis and photoluminescence spectroscopy revealed that the hierarchical heterojunction photocatalyst possessed excellent charge generation and separation efficiency. The resultant hierarchical heterojunction photocatalyst exhibited remarkable photocatalytic performance in the photodegradation of bisphenol A and photocatalytic hydrogen evolution under simulated solar irradiation. The enhancement of photocatalytic performance was mainly attributed to the combined effect of hierarchical morphology, in-situ doping, and heterojunction formation