Methyl esters from crude sunflower oil were produced via methanolysis reaction using sodium hydroxide catalyst. Methanolysis was carried out at different agitation speeds (200-600 rpm), temperatures (25-60• C), catalyst loadings (0.25-1.00% by weight of oil), and methanol:oil mole ratios (6:1-20:1). Mass-transfer limitation was effectively minimized at agitation speeds of 400-600 rpm with no apparent lag period. Lowering the temperature resulted in a fall in the rate of reaction prolonging the reaction time necessary to achieve maximum production of methyl ester. Using 0.50% hydroxide catalyst was found to be adequate, resulting in 97-98% conversion without compromising recovery due to soap formation. Increasing the methanol:oil mole ratio beyond the usual amount of 6:1 tended to speed up the initial rate of methanolysis and was found to lower the bonded glycerol content, especially the amount of diglyceride in the sample. Kinetic rate constants were derived from experimental results using second-order rate expressions, and values of activation energy for glyceride methanolysis have been established.

No abstract

Healthcare waste must be managed properly due to the hazards they impose on public health and the environment. In this study, an alternative method of treating infectious waste via thermal treatment using coconut oil was investigated in a laboratory-scale setup. The effects of oil temperature (121°C, 145°C and 170°C) and treatment time (10, 20 and 30 minutes) on bacterial growth and properties of simulated infectious wastes contaminated with Bacillus subtilis were determined. No bacterial growth was observed in the samples even at the seventh day after treatment using 145oC (20- and 30-minute treatment time) and 170°C (all treatment time). However, growth on enriched media occurred for the samples treated at 170°C, indicating possible spore germination. The treatment at 145°C and 30 minutes was effective in treating contaminated syringes and cloths. The contaminated meat samples underwent thermal degradation and had a maximum weight reduction of 74.1%, which was mainly due to moisture loss. The cloths, however, did not change in its appearance but syringes and other plastics melted and deformed. Thus, the thermal treatment was found to be a good disinfection method, causing severe damage to cells. The treated infectious waste materials can be disposed in landfills without potential recurrence of bacterial growth.

No abstract

With the implementation of the Philippine Biofuels Act of 2006, the country continues to search for new biodiesel feedstock and in improving on existing processes related to biodiesel production. In this study, contributions to these two fields of research were done. Palm oil is currently being considered at by the Philippine government as a potential biodiesel feedstock to augment coconut. This study aimed to optimize parameters for biodiesel production using refined palm oil as feedstock by varying the methanol-to-palm oil molar ratio (MeOH:PO) and the palm oil-to-sodium hydroxide molar ratio (PO:NaOH) with the aid of Response Surface Methodology (RSM) at constant temperature (30°C) and reaction time (60 min). The obtained optimum ranges are: 6.5-6.9:1 for MeOH:PO and 1:0.27-0.32 for PO:NaOH. After the optimum ranges for both ratios were determined, the effect of adding various amounts of FAME to the reaction system at the start of transesterification was studied in an attempt to break the immiscibility of methanol and oil in order to increase FAME yield. The increasing the initial amount of FAME added resulted to an increase in the amount of %FAME yield. In the experimental run where 50% by weight (wt%) of FAME was added, %FAME yield was 64%, which is more than double compared to that of the control (29%). These proved that biodiesel could be produced at milder reaction conditions and would require less energy input.

The massive spread and growth of invasive alien plant species (IAPS) such as Piper aduncum L. (PA) endanger the natural ecosystem. Utilizing their woody biomass as feedstock through gasification to produce renewable energy can reduce risk and provide better incentives to rural communities. Heating value (HV), fixed carbon (FC), volatile combustible matter (VCM), and ash content were used to compare PA with five other tree species -namely, Calliandra calothyrsus L. (CC), Gliricidium sepium L. (GS), Broussonetia papyrifera L. (BP), Eucalyptus marginata L. (EM), and Eucalyptus urophylla L. (EU) -as fuel for gasification. The effects of particle size (p s ), air volumetric flow rate (υ air ), and carbonization and their interactions to cold gas efficiency (CGE), producer gas flow rate (υ syngas ), and specific gasification rate (SGR) were also studied. The economics and environmental impact of spiked pepper as feedstock were evaluated by hypothetically putting up a 100 kWe gasification plant in the Upper Bauyan Watershed serving 138 households. With an electrical efficiency of 17.1%, the plant would need 990 tons of PA. Feedstock supply would be adequate even after 20 yr of operation since biomass growth rate would be faster than consumption rate. The computed carbon dioxide (CO 2 ) emissions annually for harvesting was 9.72 tons (shelterwood method) -781.11 tons for gasification and electrical production against direct combustion, which theoretically emits 1,729.73 tons annually. Financial analysis indicated a profitable investment with a positive net present value of PHP 6,240,257.08 or USD 122,358 (USD 1 = PHP 51), IRR of 12%, payback period of 6.97 yr, and levelized cost of electricity (LCOE) of PHP 8.90 (USD 0.17). Overall, the study indicates the economic feasibility and ecological soundness of utilizing PA as feedstock provided that silvicultural management is applied in replanting indigenous trees in eradicated lands. This method can also be effective in restoring the landscape of affected watersheds.