Selective Production of Bio-Based Linear Alpha-Olefin from Wasted Fatty Alcohol on Al2O3 for Bio-Based Chemicals.

The catalytic dehydration of a bio-based fatty alcohol was performed using Al2O3 prepared by solvothermal synthesis for selective production of long-chain linear-alpha-olefins (LAO). The effect of the synthesis temperature of alumina precursors on the dehydration of 1-octadecanol (C18H38O) was examined based on the textural properties and Lewis acid-base properties of the catalysts. Amorphous alumina synthesized at 325 °C showed the highest surface area (233.07 m2/g) and total pore volume (1.237 cm3/g) among the catalysts and the best dehydration results: 93% conversion, 62% selectivity of 1-octadecene (C18H36), and 89% LAO purity. This was attributed to the increased Al/O ratio and atomic concentration of surface O in alumina, which were important factors in the catalytic dehydration of 1-octadecanol through the synergistic catalysis of acid-base pairs. The produced bio-based LAO can be key intermediates for synthesis of oxo alcohols and poly-alpha-olefins, as alternatives to petroleum-based LAO to achieve carbon neutrality in chemical industry.

Biocompatible liquid-type carbon nanodots (C-paints) as light delivery materials for cell growth and astaxanthin induction of Haematococcus pluvialis.

In this study, we aimed to demonstrate the feasibility of the application of biocompatible liquid type fluorescent carbon nanodots (C-paints) to microalgae by improving microalgae productivity. C-paints were prepared by a simple process of ultrasound irradiation using polyethylene glycol (PEG) as a passivation agent. The resulting C-paints exhibited a carbonyl-rich surface with good uniformity of particle size, excellent water solubility, photo-stability, fluorescence efficiency, and good biocompatibility (<10.0 mg mL-1 of C-paints concentration). In the practical application of C-paints to microalgae culture, the most effective and optimized condition leading to growth promoting effect was observed at a C-paints concentration of 1.0 mg mL-1 (>20% higher than the control cell content). A C-paints concentration of 1-10.0 mg mL-1 induced an approximately >1.8 times higher astaxanthin content than the control cells. The high light delivery effect of non-cytotoxic C-paints was applied as a stress condition for H. pluvialis growth and was found to play a major role in enhancing productivity. Notably, the results from this study are an essential approach to improve astaxanthin production, which can be used in various applications because of its therapeutic effects such as cancer prevention, anti-inflammation, immune stimulation, and treatment of muscle-soreness.

Effects of Zeolite Supports on the Production of Fuel-Range Hydrocarbons in the Hydrotreatment of Various Vegetable Oils with Platinum-Based Catalysts.

The effects of catalyst supports on catalyst performance in the hydrotreatment of vegetable oils (to produce fuel-range hydrocarbons such as gasoline, jet fuel, and diesel) were investigated, using three types of zeolites (ZSM-5, HY, and zeolite-beta (BEA)) that differ in their silica/alumina ratios. Structural characterization of the catalysts was performed using ICP, XRD, BET, TEM, and NH3-TPD. Catalytic tests were carried out in a fixed-bed reaction system at 400 °C and 50 bar. In the hydrotreatment of soybean oil, higher conversions into liquid hydrocarbons and fuel-range hydrocarbons were found when supports with lower Si/Al2 ratios were used. Specifically, Pt/BEA (Si/Al2 = 25) produced the highest conversion into liquid products (72%) and the highest selectivity for hydrocarbons in the jet fuel (46%) and diesel (51%) fuels. A Pt loading amount of 3 wt% in this catalyst gave the best catalytic performance because of the optimal balance between acidic and metallic sites. Finally, the kinds of vegetable oils in the hydrotreatment performance over Pt/BEA (Si/Al2 = 25) affected the order; waste-cooking oil > jatropha oil > soybean oil.

Recent developments and key barriers to advanced biofuels: A short review.

Biofuels are regarded as one of the most viable options for reduction of CO2 emissions in the transport sector. However, conventional plant-based biofuels (e.g., biodiesel, bioethanol)'s share of total transportation-fuel consumption in 2016 was very low, about 4%, due to several major limitations including shortage of raw materials, low CO2 mitigation effect, blending wall, and poor cost competitiveness. Advanced biofuels such as drop-in, microalgal, and electro biofuels, especially from inedible biomass, are considered to be a promising solution to the problem of how to cope with the growing biofuel demand. In this paper, recent developments in oxy-free hydrocarbon conversion via catalytic deoxygenation reactions, the selection of and lipid-content enhancement of oleaginous microalgae, electrochemical biofuel conversion, and the diversification of valuable products from biomass and intermediates are reviewed. The challenges and prospects for future development of eco-friendly and economically advanced biofuel production processes also are outlined herein.

Critical Point Drying: An Effective Drying Method for Direct Measurement of the Surface Area of a Pretreated Cellulosic Biomass.

The surface area and pore size distribution of Eucalyptus samples that were pretreated by different methods were determined by the Brunauer⁻Emmett⁻Teller (BET) technique. Three methods were applied to prepare cellulosic biomass samples for the BET measurements, air, freeze, and critical point drying (CPD). The air and freeze drying caused a severe collapse of the biomass pore structures, but the CPD effectively preserved the biomass morphology. The surface area of the CPD prepared Eucalyptus samples were determined to be 58⁻161 m²/g, whereas the air and freeze dried samples were 0.5⁻1.3 and 1.0⁻2.4 m²/g, respectively. The average pore diameter of the CPD prepared Eucalyptus samples were 61⁻70 Å. The CPD preserved the Eucalyptus sample morphology by replacing water with a non-polar solvent, CO2 fluid, which prevented hydrogen bond reformation in the cellulose.