No abstract

Process simulation and techno‐economic analysis (TEA) of 95 wt % protein concentrate (water‐soluble peptides and free amino acids) from microalgae was performed using SuperPro Designer v9.0. The analysis includes processes such as microalgae cultivation, harvesting, protein extraction, and spray drying. The subcritical water‐based Flash Hydrolysis (FH) process was used in generating bench‐scale continuous flow reactor experimental data on protein extraction from microalgae slurry. The TEA is conducted for a baseline capacity of 153 metric tonnes per day (MT/day) protein concentrate production requiring a throughput of 336 MT/day dry algae assuming 54 wt % protein content. Sensitivity analysis reveals the following baseline economic figures. Fixed capital investment (FCI): $286 million; annual operating cost (AOC): $146 million; annualized cost: $185 million/year at 10% discount rate for 15 yr; unit cost of production: $2.99/kg protein depending on the algae slurry density; minimum selling price: $4.31/kg protein. © 2017 American Institute of Chemical Engineers Environ Prog, 37: 881–890, 2018

No abstract

Process optimization and reaction kinetics of catalytic transfer hydrogenation (CTH) of waste cooking oil (WCO) into jet fuels using zeolite-supported Ni−Co−Mo oxides catalyst in a packed-bed reactor were studied. Experiments were conducted at three different temperatures (360, 390, and 420 °C) to determine the rate constants, the order of reaction, and the activation energy. The kinetics study showed a first-order reaction with the activation energy estimated to be 84 ± 18.7 kJ/mol WCO with 95% confidence. Design of experiment (DOE) was employed to estimate the optimum reaction parameters using the polynomial model (383.7 °C; 14.8 bar; WCO-to-2-propanol ratio = 1.57 mL/ mL; weight hourly space velocity (WHSV) = 6.7 h −1 ). Validation of the model at the optimum operating conditions generated 80% yield of liquid products with 77% alkanes, 3.8% alkenes, and 12.3% aromatics composition, and 6.7% gases, and 100% conversion of WCO. The catalyst was prepared via the wet impregnation method and characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Brunauer−Emmett−Teller (BET) adsorption and desorption, scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), and thermogravimetric analysis (TGA). Characterization of the catalyst revealed a cubic structure, which was maintained after one cycle of CTH reaction. Present in both the fresh and the used catalysts were Na 2 O, K 2 O, MgO, Al 2 O 3 , SiO 2 , CaO, FeO, Fe 2 O 3 , which highlight the composition of zeolite. The active sites were dominated by Co 3+ , Ni 2+ , and Mo 6+ that were respectively present in the form of Co 2 O 3 , NiO, and MoO 3 .

A dramatic enhancement by a factor of 15 for the production of ozonized biochar molecular products measured as dissolved organic carbon (DOC) was achieved by an innovative biochar ozonization process. The filtrate of the ozonized biochar molecular products contained substantially more carboxyl groups than that of the nonozonized biochar. The ozonized biochar molecules are now identified to be highly potent, even at a ppm DOC concentration level, to "unlock" phosphorus (P) from insoluble phosphate material hydroxyapatite (HA). At a DOC concentration of 600 ppm, the filtrates from the wet-ozonized pine 400 biochar and the dry-ozonized rogue biochar substances were both able to solubilize HA, resulting in a concentration of solubilized phosphorus up to 396.8 ± 28.8 and 339.6 ± 8.5 mg HPO 4 2− /L, respectively. Even at a DOC concentration as low as 10 ppm, the ozonized biochar molecules solubilized up to 8.3 ± 1.1 mg/L of phosphate. At neutralized pH 7, the efficiency in solubilizing phosphate decreased, indicating the importance of the protonic effect. The ozonized biochar organic acids solubilized more phosphate than a hydrochloric acid solution with the same pH, thus showing the applicability of this green chemistry with ozonized biochar molecules to unlock P from insoluble phosphate rock materials. The discovery of ozonized biochar molecules capable of unlocking P is highly relevant to agricultural phosphorus and environmental sustainability on the Earth.