Effects of Water Removal from Palm Oil Reactant by Electrolysis on the Fuel Properties of Biodiesel

Biodiesel, which is composed of mono-alkyl esters of long carbon-chained fatty acids, is used as an alternative fuel to petro-diesel. The water content of the reactant mixture of feedstock oil influences the extent of transesterification and thus the fuel characteristics. Lower water content in feedstock oil is generally suggested for successful transesterification. This experimental study removed water from the reactant mixture of feedstock palm oil and methanol during transesterification using various systems composed of either electrodes or molecular sieves with rotary vibration. The effect of input electrical energy, number of electrodes, vibration modes, and operating time on the amount of water removed from the reactant mixture and the fuel properties of the final biodiesel product were analyzed and compared with those achieved using molecular sieves. The results show that the biodiesel—after water was removed during transesterification—appeared to have increased kinematic viscosity, cetane index, distillation temperature, and acid value, while the heating value, flash point, ignition point, and water content decreased with an increase in the input electrical energy of the electrodes responsible for electrolyzing water away. Electrolysis by the double-pair electrodes was more effective at reducing acid value and water content than that performed by the single-pair electrodes under the same input electrical energy. The biodiesel was found to have the lowest water content (0.0304 wt.%) and the highest water-removal rate (0.011 wt.%) when water was removed during transesterification by the double-pair electrodes with an input electrical energy of 9 J/(g palm oil). The water-removal rate of the rotary-vibrating molecular sieves was 11.24 times that of the single-pair electrodes. The biodiesel was found to have increased kinematic viscosity with higher input electrical energy, reaching 5.15 mm2/s when the double-pair electrodes with an input electrical energy of 11 J/(g palm oil) were used. Longer carbon-chained fatty acids, ranging from C20 to C24, amounted to 0.74 wt.% of the biodiesel produced using the double-pair electrodes, which was greater than that seen for the single-pair electrodes. However, the molecular sieve method consumed more energy than the double-pair electrodes did to remove the same amount of water from the palm oil reactant mixture via transesterification.

Effect of grated coconut and water ratio and commercial cheese starter percentage on characteristics of soft cheese made from coconut milk

The aim and objective of this research was to produce a soft cheese made from coconut milk and to examine the effect of grated coconut:water ratio (1:1, 1:2 and 1:3) and percentage of commercial cheese starter culture (1% and 1.5%) on its characteristics. The study was conducted using a factorial randomized block design. After two weeks of storage at 4°C, the cheeses (18 samples) were analysed for total lactic acid (LAB) counts, pH, and fat content. The lowest-fat coconut cheese was analysed for proximate and spreading ability. The results showed that the grated coconut:water ratio had a significant effect (P≣0.01) on the total LAB counts, pH value, and fat content of the cheese. The optimum formulation for soft cheese was selected based on the lowest pH (4.64) and fat content (42%) which was reached by using coconut and water 1:1. However, the spreading ability of this cheese could be improved by optimising the growth of starter cultures, water removal and adding stabilizers.

Elimination of Tight Emulsions

Maturing oil fields can pose a severe challenge for separation of oil and water. Increasing water production and tie in of new fields into existing infrastructure may result in separators struggling to meet performance specifications. Operational challenges are particularly experienced when the facilities are processing cold feedstock and tight emulsions. Typical solutions for overcoming separation challenges would be increasing operating temperature, injecting an increased quantity of demulsifier chemicals, or installing new larger separators. These alternatives may not be economically attractive or feasible for other reasons. The ability to successfully operate existing plants with tight and water-rich emulsions without incurring significant added operating expenditure is perceived as a major advantage. This paper will share the results from testing on a separator operating with Flotta Gold crude oil. The oil is known to produce particularly tight emulsions at low temperatures. The ePack technology has been tested to study its capability of separating water and crude oil from tight emulsions by means of electrical forces. The force generated by the high electrical field can break even tight emulsions, and the test results shown have proven the ability to go from very low separation efficiency without the ePack, to more than 90% water removal with the ePack turned on. Testing with residence times of up to 19 minutes without the ePack was not able to surpass the performance of a three minutes residence time with the ePack energized.

Design strategies for oxy-combustion power plant captured CO2 purification

This study presents a novel design and techno-economic analysis of processes for the purification of captured CO2 from the flue gas of an oxy-combustion power plant fueled by petroleum coke. Four candidate process designs were analyzed in terms of GHG emissions, thermal efficiency, pipeline CO2 purity, CO2 capture rate, levelized costs of electricity, and cost of CO2 avoided. The candidates were a classic process with flue-gas water removal via condensation, flue-gas water removal via condensation followed by flue-gas oxygen removal through cryogenic distillation, flue-gas water removal followed by catalytic conversion of oxygen in the flue gas to water via reaction with hydrogen, and oxy-combustion in a slightly oxygen-deprived environment with flue-gas water removal and no need for flue gas oxygen removal. The former two were studied in prior works and the latter two concepts are new to this work. The eco-technoeconomic analysis results indicated trade-offs between the four options in terms of cost, efficiency, lifecycle greenhouse gas emissions, costs of CO2 avoided, technical readiness, and captured CO2 quality. The slightly oxygen-deprived process has the lowest costs of CO2 avoided, but requires tolerance of a small amount of H2, CO, and light hydrocarbons in the captured CO2 which may or may not be feasible depending on the CO2 end use. If infeasible, the catalytic de-oxygenation process is the next best choice. Overall, this work is the first study to perform eco-technoeconomic analyses of different techniques for O2 removal from CO2 captured from an oxy-combustion power plant.