Low-cost alternative biodiesel production apparatus based on household food blender for continuous biodiesel production for small communities.

Fatty acid methyl esters (FAMEs) are sustainable biofuel that can alleviate high oil costs and environmental impacts of petroleum-based fuel. A modified 1200 W high-efficiency food blender was employed for continuous transesterification of various refined vegetable oils and waste cooking oil (WCO) using sodium hydroxide as a homogeneous catalyst. The following factors have been investigated on their effects on FAME yield: baffles, reaction volume, total reactant flow rate, methanol-oil molar ratio, catalyst concentration and reaction temperature. Results indicated that the optimal conditions were: 2000 mL reaction volume, 50 mL/min total flow rate, 1% and 1.25% catalyst concentration for refined palm oil and WCO, respectively, 6:1 methanol-to-oil molar ratio and 62-63 °C, obtaining yield efficiency over 96.5% FAME yield of 21.14 × 10-4 g/J (for palm oil) and 19.39 × 10-4 g/J (for WCO). All the properties of produced FAMEs meet the EN 14214 and ASTM D6751 standards. The modified household food blender could be a practical and low-cost alternative biodiesel production apparatus for continuous biodiesel production for small communities in remote areas.

Innovative seawater uranium recovery agent based on low-cost polyacrylonitrile fibers.

An innovative seawater uranium adsorbent was prepared from the low-cost and commercially-available polyacrylonitrile (PAN) fibers. The optimum condition to synthesize the adsorbent was to irradiate the PAN fibers with 100 kGy gamma ray, amidoximate in 3 (w/v)% hydroxylamine hydrochloride solution for 75 min at 75 °C, yielding the PAN nitrile group conversion of approximately 60%. At 100 kGy, the degree of crystallinity of the irradiated fibers was also highest at 79.1%. The performances of the adsorbent in seawater samples were excellent. By submersion in the seawater sample spiked with 250 ppb of uranium for 4 weeks, the prepared fibers exhibited the adsorption capacity of 32.28 mg/g adsorbent. By submersion in seawater samples spiked with 76.5 ppm of uranium for 1 week and 945 ppm of uranium for up to 4 weeks, the fibers exhibited the adsorption capacities of 111.25 and 200.07 mg/g adsorbent, respectively. The adsorbent showed a uranium adsorption capacity of 0.11 mg/g adsorbent for 8 weeks of soaking in brine concentrate from a seawater reverse osmosis plant. The kinetics of seawater absorption by the adsorbent was quite rapid, reaching the equilibrium swelling ratio of approximately 300% in 5 min or less. Another important finding was that the prepared PAN fibers exhibit the characteristics of a superabsorbent material (equilibrium swelling ratio in DI water of 5,550%). The low cost and the ease of preparation of the fibers offer a novel environmental remediation process to adsorb uranium ions released into seawater following a nuclear accident.