937 resultados para Oil content
Resumo:
Presumed synergistic effect of combined amendment of crude oil spiked soil with oil palm bunch ash and sawdust was carried out in a laboratory experiment. Two kilogram (2 kg) of sandy soil was placed in each of five plastic vessels labeled TA, TB, TC, TD and TE. TA was left in its natural state while the others were each polluted with 6.7% v/w of crude oil. TB was not given any remediation amendment. TC and TD were each amended with 13.3% of oil palm bunch ash and sawdust respectively while TE was amended with 13.3% each of oil palm bunch ash and sawdust. The setups were replicated five times and watered twice weekly. Results showed that soil pH increased from 8.7±0.04 to 10.5±0.06, 5.3±0.01 to 8.5±0.04 and 5.6±0.18 to 11.5±0.15 for TC, TD and TE respectively. Percentage total petroleum hydrocarbon contents reduced by 65% for TC, TD and 52% for TE. Total organic carbon increased from 7.6±0.7 to 8.5±0.5%%, reduced from 4.0±0.1% to 3.7±0.3% and from 4.1±0.1% to 2.2±1.0% TC, TD and TE respectively. Total nitrogen increased from 0.66±0.1 to 0.69±0.0% for TC, remained nearly the same for TD and reduced from 0.4±0.0 to 0.2±0.0% for TE while average phosphorus increased from 0.4±0.0 to 23.0±4.2 mg/kg, 0.3±0.0 to 1.8±0.4 mg/kg and from 0.2±1.0 mg/kg to 52.6±4.6 mg/kg for TC, TD and TE respectively. Conclusively, combined amendment with oil palm bunch ash and sawdust did not induce synergism in soil total petroleum hydrocarbon content reduction.
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This study investigates fast pyrolysis bio-oils produced from alkali-metal-impregnated biomass (beech wood). The impregnation aim is to study the catalytic cracking of the pyrolysis vapors as a result of potassium or phosphorus. It is recognized that potassium and phosphorus in biomass can have a major impact on the thermal conversion processes. When biomass is pyrolyzed in the presence of alkali metal cations, catalytic cracking of the pyrolysis liquids occurs in the vapor phase, reducing the organic liquids produced and increasing yields of water, char, and gas, resulting in a bio-oil that has a lower calorific value and an increased chance of phase separation. Beech wood was impregnated with potassium or phosphorus (K impregnation and P impregnation, respectively) in the range of 0.10-2.00 wt %. Analytical pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) was used to examine the pyrolysis products during thermal degradation, and thermogravimetric analysis (TGA) was used to examine the distribution of char and volatiles. Both potassium and phosphorus are seen to catalyze the pyrolytic decomposition of biomass and modify the yields of products. 3-Furaldehyde and levoglucosenone become more dominant products upon P impregnation, pointing to rearrangement and dehydration routes during the pyrolysis process. Potassium has a significant influence on cellulose and hemicellulose decomposition, not just on the formation of levoglucosan but also other species, such as 2(5H)-furanone or hydroxymethyl-cyclopentene derivatives. Fast pyrolysis processing has also been undertaken using a laboratory-scale continuously fed bubbling fluidized-bed reactor with a nominal capacity of 1 kg h-1 at the reaction temperature of 525 °C. An increase in the viscosity of the bio-oil during the stability assessment tests was observed with an increasing percentage of impregnation for both additives. This is because bio-oil undergoes polymerization while placed in storage as a result of the inorganic content. The majority of inorganics are concentrated in the char, but small amounts are entrained in the pyrolysis vapors and, therefore, end up in the bio-oil.
Resumo:
Water contamination can cause serious problems that compromise in transformer's safe operation and reduce its lifetime. Online monitoring of moisture concentration in transformer oil would permit the control of moisture buildup. This letter presents a direct optical measurement of moisture concentration in transformer oil using a poly(methyl methacrylate) (PMMA)-based optical fiber Bragg grating (POFBG). The refractive index and volume of PMMA-based optical fiber vary with the moisture in the surrounding transformer oil, changing the reflecting wavelength of the grating. A sensitivity of POFBG wavelength change to moisture content of 29 pm/ppm is demonstrated in this letter, indicating detectable water content better than 0.05 ppm.
An empirical investigation of the impact of global energy transition on Nigerian oil and gas exports
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Changes in soil sulfur (S) fractions were assessed in oil palm and food garden land use systems developed on forest vegetation in humid tropical areas of Popondetta in northern Province. The study tested a hypothesis that S in food gardens are limiting nutrient factor and are significantly lower than in plantations and forests. Subsistence food gardens are under long-term slash and burn practice of cropping and such practice is expected to accelerate loss of biomass S from the ecosystem. From each land use, surface soil (0–15 cm) samples were characterised and further pseudocomplete fractionated for S. Conversion of forest to oil palm production decreased (p<0.001) soil pH and electrical conductivity values. The reserve S fraction in soil increased significantly (p<0.05) due to oil palm production ( 28 %) and food gardening activity (∼ 54 %). However, plant available SO42--S was below 15 mg kg^(−1) in the food garden soils and foliar samples of sweet potato crop indicating deficiency of plant available S. Soil organic carbon content (OC) was positively and significantly correlated to total S content (r=0.533; p<0.001) among the land use systems. Thus, crop management practices that affect OC status of the soils would potentially affect the S availability in soils. The possible changes in the chemical nature of mineralisable organic S compounds leading to enhanced mineralisation and leaching losses could be the reasons for the deficiency of S in the food garden soils. The results of this study conclude that long-term subsistence food gardening activity enriched top soils with reserve S or total S content at the expense of soluble S fraction. The subsistence cropping practices such as biomass burning in food gardens and reduced fallow periods are apparently threatening food security of oil palm households. Improved soil OC management strategies such as avoiding burning of fallow vegetation, improved fallows, mulching with fallow biomass, use of manures and S containing fertilisers must be promoted to sustain food security in smallholder oil palm system.
Resumo:
Abstract: The aim of this study is to characterize physical and chemically and determine the antioxidant capacity of pequi almond oils (PAO) extracted by handmade and by cold-pressing. Both oils showed good quality by acid, peroxide and thiobarbituric acid values. The fatty acid (FA) profile showed a significant presence of monounsaturated FA, mainly oleic acid (53.48 to 55.41%); saturated FA, such as palmitic acid (33.30 to 35.89 %); and polyunsaturated FA (PUFA), such as linoleic acid (5.85 to 7.23%). The total phenolic (TP) and carotenoid content ranged in concentration from 87.56 to 392.00 mg GAE/100 g and 36.03 to 262.40 mg/100 g, respectively. The tocopherol and phytosterol results indicated the predominant presence of α-tocopherol (52 to 67%) and stigmasterol (63 to 68 %). The antioxidant capacity of PAO as measured using the 2,2-diphenyl-1-picrylhydrazyl (DPPH?) method oscillated from 58.48 mg/mL to 76.46 mg/mL (IC50), from 10.61 to 40.46 µmol TE/g by the 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS?+) method, and from 113.93 to 280.85 µmol TE/100 g and 164.49 to 277.86 µmol TE/100 g, by the lipophilic and hydrophilic oxygen radical absorbance capacity (ORAC) methods, respectively. The oils presented a good oxidative and thermal stability by Rancimat method (IP of 7.33 a 15.91 h) and curves thermogravimetric and differential scanning calorimetry (To 337-363 °C and 159-184 °C, respectively). The results confirmed the presence of compounds that conferred antioxidant capacity and oxidative and thermal resistance for PAO made by handmade or cold-pressing, indicating that these oils can potentially be used for food and non-food applications.