Methanol Production from Cow Dung

The amount of agricultural biodegradable wastes generated in Nigeria is constantly on the increase. These wastes are mainly cellulosic materials from reared animal (feaces) and plants. The environmental awareness of most Nigerians is also far better than it used to be in about 30 years back. Accordingly, the paper considers economical use of one of this agricultural wastes-cow dung. The waste was anaerobically digested and acid treated in sequence to produce storable form of alternative energy, while the left over sludge could be used as a good quality farmland fertilizer. The quantities/qualities of methane gas and methanol produced were found to depend on slurry concentration, incubation period, pH value, operating temperature and carbon/nitrogen ratio of the dung. The gas chromatographic analysis conducted indicated that the unrefined biogas was determined to contain 57.23 mol% CH4, 42.65mol% CO2, 0.21mol% H2S, 0.07mol% NH3 and others. The refined biogas was analyzed and the composition was established to be: 59.45mol% CH4, 14.65mol% CO2, 0.11mol% H2S, 0.04mol% NH3 and others. This refinement was found to enhance the C/N ratio, making the organic component readily available for the acidic reaction. Spectroscopic analysis of the obtained liquid sample indicated formation of methanol. The purity of methanol produce was determined to be 92.5%, which compared slightly favorably with literature value of 98.9%. The boiling point and heat of combustion were found to compare favorably with literature values. The C/N ratio determined after the demethanization was found to be lower compared to the starting C/N ratio and the gang served as good source of manure. Keywords- biomass, cow dung, fertilizer, methanol, renewable energy, methane, manur

Immobilization of Cassava Linamarase on Kankara Kaolinite Clay

The enzyme, linamarase was successfully extracted and immobilized on pretreated Kankara kaolinite clay, serving as substitute for other expensive catalysts supports. Acid treatment of the clay was observed to affect the activity of linamarase. The activity of the enzyme was higher in the cortex compared with both in the stem and the leaves. Enzyme activity was observed to increase with increase in the silica contents of the treated clay. Operational stability/activity of the immobilized enzyme was found to reduce by about 50% after 18days at room temperature, following first order denaturation reaction, with rate constant k obtained to be 0.03day-1 with R2 0.957. The Km and Vmax were determined to 0.1986mM-1 and 10.01mM/min respectively, which is an indication of the enzyme’s affinity to the support used. The specific surface area and pore size of kaolin were also found to decrease with rate of enzyme anchoring, pointing to occupation and/or blockage of the available pore. Kankara kaolinite clay is a promising cheaper support material for linamarase immobilization. Keywords: linamarase, immobilization, kaolinite clay, cassava, metakaolin, cyanoge

Synthesis of Zeolite ZSM3 from Faujasite: Effects of Post-synthesis Ageing and Insitu seeding

The crystallization of ZSM3 via faujasite metamorphosis, synthesized from dealuminated metakaolin, was achieved without the addition of any structure directing agent. The XRD, XRF, and SEM/EDXS analyses carried out on the sample indicated successful synthesis of matrix, containing zeolites X, Y and sodium aluminosilicate, in various proportions, which was later transformed completely into ZSM3. The XRD peaks and SEM morphologies attributed to ZSM3 increased in intensity and crystallinity, as reaction and ageing time progressed. Post synthesis effects i.e. exposure to dampness and longer contact time in the presence of residue/unwashed NaOH used for the synthesis earlier, were totally responsible for the metamorphosis. Anatase and quartz were observed to persist in the raw, intermediate and as-synthesized product, pointing to their high level of resistances to treatments. The formation of competitive zeolite phases, was prevented by controlling factors responsible for its nucleation and formation. Keywords: metamorphosis, insitu seeding, kaolin, ZSM3, faujasite, dealumination, agin

On the prediction of power loss in helical gearbox via simulation approach

Frictional loss, load variation, viscosity and speed are major causes of power loss in helical gears under normal operating conditions. The study presents the major theoretical findings to predict the possible power loss in a helical gear box. First, an analytical technique was employed to model the frictional loss and coefficient of friction resulting from the heat generated for a pair of helical gear in mesh. Then, a finite element method and Comsol Multiphysics was applied to model the helical gear structure as well as the surface displacements under static and moving conditions of the pinion. It was observed that the highest amplitude in surface displacement was 14 ×1

Progress and challenges of demand-led co-produced sub-seasonal-to-seasonal (S2S) climate forecasts in Nigeria

This paper identifies fundamental issues which prevent the effective uptake of climate information services in Nigeria. We propose solutions which involve the extension of short-range (1 to 5 days) forecasts beyond that of medium-range (7 to 15 days) timescales through the operational use of current forecast data as well as improve collaboration and communication with forecast users. Using newly available data to provide seamless operational forecasts from short-term to sub-seasonal timescales, we examine evidence to determine if effective demand-led sub-seasonal-to-seasonal (S2S) climate forecasts can be co-produced. This evidence involves: itemization of forecast products delivered to stakeholders, with their development methodology; enumeration of inferences of forecast products and their influences on decisions taken by stakeholders; user-focused discussions of improvements on co-produced products; and the methods of evaluating the performance of the forecast products. We find that extending the production pipeline of short-range forecast timescales beyond the medium-range, such that the medium-range forecast timescales can be fed into existing tools for applying short-range forecasts, assisted in mitigating the risks of sub-seasonal climate variability on socio-economic activities in Nigeria. We also find that enhancing of collaboration and communication channels between the producers and the forecast product users helps to: enhance the development of user-tailored impact-based forecasts; increases users’ trusts in the forecasts; and, seamlessly improves forecast evaluations. In general, these measures lead to more smooth delivery and increase in uptake of climate information services in Nigeria

Statistical-based performance evaluation of inhibitors on the corrosion of steel rebar in concrete

This paper explores the performance evaluation of some corrosion inhibitors on the corrosion of steel rebar in concrete immersed in dilute sulphuric acid and sodium chloride solutions as a means of achieving preventive maintenance for sustainable development of engineering facilities. The open circuit potential (OCP) corrosion monitoring technique was employed for both the acidic and the marine simulating environments. For these, potential readings were taken in accordance with ASTM C876. Voltage readings were recorded for each block of thirty specimens at two-day interval for thirty-two days. Inhibiting quality and uniformity of the inhibitors were then analyzed using an extreme value statistical modelling approach of the Weibull probability density distribution for determining the most efficient inhibitor. In the inhibitor concentrations considered, the statistically analyzed experimental results identified 4.5g of potassium chromate as exhibiting the best inhibiting quality in sulphuric acid whereas the synergetic admixture of 1.5g potassium dichromate + 3.0g potassium chromate is predicted as showing the lowest probability of corrosion risk in sodium chloride solutions. However, the overall probabilistic results rated potassium chromate as better inhibitor compared to potassium dichromate in most of the other concentrations investigated in the work, especially in concrete structures exposed to marine environments

Effect of synergies of K2Cr2O7, K2CrO4, NaNO2 and aniline inhibitors on the corrosion potential response of steel reinforced concrete in saline medium.

Studies involving performance of corrosion inhibitors had been identified as one of the critical research needs for improving the durability of concrete structures. This paper investigates the effect of synergy on the performance of potassium chromate, sodium nitrite and aniline as inhibitors on the corrosion of steel-rebar in concrete in sodium chloride medium. The corrosion monitoring technique of the open circuit potential was employed for specimens of steel-reinforced concrete, with different synergistic admixtures of K2Cr2O7, K2CrO4, NaNO2 and Aniline, partially immersed in the marine simulating environment. Interpretation of the statistical modelling of the experimental results, for each of the synergistic concentrations of inhibitor admixtures studied, was done using ASTM C876. The modelled ranking from these predicted the synergistic combination of 3.0g (0.064 M) K2Cr2O7 + 4.5g (0.145M) K2CrO4 + 3.0g (0.272M) NaNO2 + 4ml (0.274M) Aniline as exhibiting optimal inhibiting quality on the corrosion of steel-reinforced concrete in the chloride medium considered

Investigating potassium chromate and aniline effect on Concrete Steel rebar degradation in saline and sulphate media

Potential monitoring experiments were performed on steel rebars embedded in concrete admixed with potassium chromate, aniline and their synergetic combinations with fixed amount of sodium chloride salt partially immersed in sulphuric acid and sodium chloride solution. Two-sets of fifteen steel-rebar concrete specimens were employed for the study and potential readings were taken in accordance with ASTM C 876. Quality and consistency of the inhibitor was then estimated by the Weibull probability density distribution as an extreme value statistical modeling approach to study the efficacy and predict the most efficient inhibitor concentration in each media. The effect of the inhibitors on the compressive strengths of the test samples was also conducted. Results revealed that test sample admixed with 0.15M potassium chromate partially immersed in sulphuric acid medium exhibited the best overall performance while 0.34M aniline admixture was identified as exhibiting the best performance in the sodium chloride medium. The results also show that the admixture combination of 0.15M potassium chromate and 0.07M aniline in the sodium chloride medium produced the best result amongst the synergistic combination used. Control sample in the saline medium gave the highest increase in compressive strength (330KN) amongst all the samples considered. Also, in the NaCl medium the 0.14M aniline admixture gave the highest increase in compressive strength amongst the inhibited samples. However, the 0.41M aniline admixture gave the highest increase in compressive strength amongst all the samples considered in the H2SO4 medium. © 2014 by ESG