Iranica Journal of Energy & Environment
Volume:8 Issue: 1, Winter 2017

In this work, isothermal gasification reactivity of pistachio nut shell (PNS) char and oil palm shell (OPS) char was studied under CO2 using Thermogravimetric analysis (TGA). The effects of temperature, inherent alkali content and surface area of each biomass char on promotion of CO2 gasification reactivity were investigated. The achieved results revealed the profound catalytic effect of alkali, alkaline and transition metals including K, Na and Fe available in the ash of biomass on enhancing the gasification reactivity of the char at temperatures below 900 °C. However, at elevated temperatures the pore diffusion was dominant and controlled the gasification reactivity. It was found that at temperatures below 900 °C, PNS char demonstrated high gasification reactivity because of its high alkali index, while at any temperature above 900 °C, conversion of OPS char was faster due to its high porosity and larger surface area.

Day by day the energy consumption is very rapidly increasing. The world’s fossil fuel supply will be depleted in future. The rate of energy consumption is increasing the supply is depleted resulting in inflation and energy shortage. This is called the energy crisis. Alternate or renewable energy resources are very essential to develop for future energy requirement. Biodiesel is the best alternative to petro-diesel. The present research work deals with the production of biodiesel from Kusum oil. Kusum oil methyl ester (KOME) was produced using a two-stage esterification cum transesterification process on account of the high free fatty acid (FFA) contents of the oil. From the above study it may be concluded that Kusum oil is a promising feedstock for biodiesel production and may be the best alternative of petro-diesel The biodiesel property of Kusum oil methyl ester (KOME) has been characterized and it shows that KOME meets the properties of biodiesel as stated in ASTM/EN standards.

Till now the conversion efficiency of the commercial photovoltaic (PV) solar modules is in the range of 14 to 20%. Therefore, PV power plants need very large area to achieve the desired output power. This paper presents some proper calculations to estimate land area occupied by the PV array. Calculations for the minimum and the maximum land area for a range of PV array with power capacity from 1 to 250 kW for different latitudes in the northern hemisphere were presented. Six different PV modules were selected for the calculation. A group of correlations are presented to roughly estimate both the land area and the number of PV modules per row as a function of the total power capacity required. In addition, correlations suggested to calculate the spacing between the rows in the PV array as a function of local latitude.

Biofuel production by a sustainable method using microalgae is entirely dependent on biomass production. However, commercialization at large scale using microalgae is a major obstacle using analytical grade growth nutrients, due to their cost effectiveness. Hence, development of a cost effective method is essential to reduce the production cost. Therefore, the present study envisaged the effect of low-cost commercial fertilizers such as urea, sodium bicarbonate, magnesium sulfate, potash and di-ammonium phosphate as growth nutrients for the production of biomass and total lipid of Botryococcus braunii were made. The biomass and total lipid production were optimized using Response Surface Methodology by 25 Central Composite Design. The result showed 225 mg L-1 of urea, 650 mg L-1 of sodium bicarbonate, 225 mg L-1 of magnesium sulfate, 150 mg L-1 of potash and 15 mg L-1 of di-ammonium phosphate supported the algal growth with a maximum biomass and total lipid of 0.792 gL-1 dry wt.. and 260 mg L-1 dry wt.., respectively. The biomass productivity of alga B. brauniiat the above condition recorded as 0.04 gL-1 day-1 with a generation time of 1.90 days.

The aim of this study was to investigate MTBE removal efficiency using sequencing batch airlift reactor (SBAR) and to determine the share of aeration and adsorption processes during the operation. The present study was conducted with a new design of the system (cubic area and embedded baffle). The reactor was applied in 4-h cycles, which included 2 min filling, 210 min aeration, 5 min sedimentation, 8 min draw, and 15 min idle time. One week after start-up, the initial brown granules were observed. During the operation, some granules were formed with the size of 2–6 mm, average settling velocity and density of 0.66 cm/s and 0.06 g/mL, respectively. The results showed that COD removal efficiency was over 94 percent.

In this study the performance of integrated fixed film activated sludge system (IFAS) in Amol industrial wastewater treatment plant (Amol, Iran) in treatment of food industrial wastewater was investigated. In addition, kinetic coefficients were evaluated for the system. The capacity of this system was 1700 cubic meters per day; that includes different process comprising physical and biological treatment, disinfection, sludge thickening, digestion and dewatering. COD removal efficiency and kinetic coefficients including yield coefficient (Y), half saturation coefficient (Ks), maximum substrate utilization rate constant (k) and endogenous decay coefficient (kd) were evaluated. The obtained results demonstrated that except Ks other coefficient were in the normal range that was frequently reported for conventional activated sludge in the literature. The COD removal efficiency was about 98 to 99 percent. The results indicated that there is a direct relationship between the variation of kd and Ks with effluent substrate concentration; while, the relationship between rate constant (k) and effluent COD is reversed. Finally, the effect of increasing sludge retention time (SRT) on COD removal was also studied. It was concluded that COD removal increased with an increase active solid retention time to a certain point, behind that point there was no significant changes observed.

The activated charcoal (AC) was synthesized from banana leaf rim (BLR) through three activation methods; physical (BLRC), chemical (Z BLRC, zinc chloride) and microwave activation (MW BLRC). The AC was characterised using powder X-ray diffraction (XRD) and field emission scanning electron microscope (FE-SEM). The Z BLRC has better adsorbent character compared to BLRC or MW BLRC. Adsorption of acetic acid (AA) onto synthesized activated charcoals (BLRC, Z BLRC & MW BLRC) were performed. This experimental data satisfied Freundlich adsorption isotherm equations. Second-order kinetics study holds good for the present adsorption system. Thermodynamic parameters were evaluated. Based on the result it may be concluded that chemical activated charcoal has maximum adsorption efficiency among the three synthesized types of carbons.

The energy demand of the wastewater treatment is contributing with a significant share to the running costs. Through optimization of the technology and the process control, the specific energy demand can be reduced to

Prosopis juliflora pods is a low cost material obtained from semi-arid region, was evaluated as adsorbent for the removal of binary textile dye mixture (Gold HE-R and Green HE-4BD). The effect of pH, concentration of dyes, adsorbent dose and contact time were obtained in batch adsorption technique. The results were analyzed by isotherm models (Freundlich, Langmuir, Redlich-Peterson and Tempkin). The results were in good agreement with Langmuir model and the Redlich-Peterson isotherm models. Langmuir monolayer adsorption quantity was found to be, 50.0 mg g-1 and 62.5 mg g-1 for Gold HE-R and Green HE-4BD, respectively. Pseudo-first-order, pseudo-second-order, intra particle diffusion and Tempkin kinetic models were used to fit the experimental data, it was well fitted into pseudo second order kinetics. Thermodynamic parameters such ΔHo, ΔSo and ΔGo were calculated, which shows the adsorption process was exothermic, decreasing randomness of solute and negative free energy reveals the feasibility of the reaction. Energy of activation also predicted using Arrhenius equation, which was -16.569 and -20.710 kJ mol-1 for GHER and GHE4BD, respectively. FT-IR and SEM analysis were also indicates the adsorption pattern effectively.

Activated sludge process is feasible and extensively method used for biological treatment of sewage and industrial wastewaters. The system is usually designed based on the simplified hydraulic related parameters. But design of biological treatment system based on hydraulic considerations is not reasonable to ensure efficient treatment due to the extensive variation in the composition of wastewater and also for complex nature of biochemical reactions occurring in the treatment processes. Hence kinetic approach can be an option for appropriate design of biological treatment systems rather than hydraulic parameters considerations. The present study is aimed to develop kinetic coefficients for the treatment of chrome-tannery wastewater using activated sludge process. A laboratory-scale treatment unit subsuming an aeration tank and a clarifier were used for this system. The treatment unit was operated continuously for 80 days by varying the hydraulic retention time from 3 to 12 days. BOD for both influent and effluent as well as mixed liquor volatile suspended solid (MLVSS) of aeration tank were determined at different retention time to yield data for kinetic coefficients. The substrate utilization rate coefficient (k) was 0.624 day−1 while the half velocity constant (KS) was 38.42 mg/L, yield coefficient (Y) was found to be 0.674 mgMLVSS/mgBOD and the endogenous decay coefficient (Kd) was found as 0.068 day-1. These coefficients can be utilized for the rational design of activated sludge system for the treatment of chrome tannery wastewater.

The Natural coagulant Vigna mungo, Zea mays were used to remove the turbidity from synthetic wastewater . Vigna mungo, Zea mays are ancient crop and having high proteins and nutrients. Chemical coagulants used it induce Alzheimer’s, Carcinogenic and neurotoxic health effects. This is alternative method for turbidity removal in synthetic wastewater. In this study Vigna mungo, Zea mays, Allium cepa ash, waste tea powder ash, Phyllanthus niruri ash used for turbidity removal. Vigna mungo seeds extract have highest percentage (90%) turbidity removal compared to Zea mays (76%). Microwave and ultrasonic assisted both methods are very efficient; 87% of turbidity removal achieved for Vigna mungo; 70% for Zea mays. Allium cepa peel ash, Waste tea powder ash, Phyllanthus niruri ash approximately almost above 95% of turbidity removal achieved. The various optimized parameters were studied and results are discussed. Natural coagulants are eco-friendly method for turbidity removal because the sludge disposal is very easy. The sludge it can be used as biocompost or biofertilizer.

The exposure level of gamma radiation and its consequent annual dose rate from the blocks faculty of sciences University of Uyo, Nigeria were investigated. An in -situ measurements of the exposure level were conducted using Radex radiation meter model RD 1212. The mean exposure measured for the different locations within the departments ranged between 0.096 ± 0.003 μSv/h μSv/h to 0.140± 0.007 μSv/h and the corresponding calculated annual dose rate (ADR ) ranged between 0.742 ± 0.021 mSv/y to 0.981± 0.049 mSv/y with department of chemistry contributing the highest value. Taking the football field as the reference site, the results show that the presence of chemicals have slightly increased the radiation level in the studied area; but not large enough for being concern as the annual dose rate is below the acceptable dose limit of 1mSv/y for the public and 20mSv/y occupational limit for personnel in the department. The area of study is new hence it is recommended that routine radiation level monitoring should be carried out for possible rise in the radiation level to be observed. For the safety, it is recommended for staff and students should spend less time indoors. The proper application of gamma rays are used for sterilization and cancer therapy.

This study concentrates on pelletization of powdered corn cob and wheat dust with 40% Epoxy binder. Two cylindrical pellets of different sizes and a new hexagonal one were investigated in this work. By densification process, the bulk density increased 8-10 times, having its maximum value fora hexagonal shape (new shape). It was found that the compressive resistance, the water resistance and the impact resistance of the pellets were in general higher for pellets produced at higher pressure. It was found that due to the binder and pelletization, the fuel quality was enhanced compared to the raw biomass as: the moisture content decreased, both fixed carbon and carbon contents increased, ash content reduced, oxygen content decreased and higher heating value (H.H.V) increased. Scanning Electron Microscopy was used to identify the binding mechanism of biomass dust particles in pellets. Pelletization process had improved combustion characteristics compared to raw biomass as: high combustion temperature ranges [T_onset becomes lower and T_offset becomes higher], maximum weight loss rates decreased and reduced residues which leads to a higher combustion efficiency. The analysis of ash yields of combustion process was investigated. It was found that the fouling index (FI) and slagging index (SI) tendency of wheat dust pellets are higher than that of corn cob pellets.

Severity of energy crisis is so acute in our society whereas environmental degradation is another challenging issue. Combining these two, environmental pollution can be eradicated permanently which is the burning issue for many countries of the world. Nowadays recycling of tire waste can be a dependable solution for minimizing energy crisis and environmental pollution as well as energy crisis. Similar to bio resources these wastes tire have the features of manufacturing energy by altered thermochemical conversion process. In the previous time waste tire pyrolysis was conducted without catalyst whereas the present pyrolysis with catalyst. The objectives were investigating the effect on oil extraction and the composition of derivative oil from tire waste in presence of catalyst. The effect of pyrolysis heating rate, temperature, operating time, catalyst/tire ratio (CT ratio) and sample size etc. on yield were also investigated. The pyrolysis process was carried out in temperature range of 300 to 600ºC. The most favorable pyrolytic oil attained was 42.0% (wt) for without catalyst as well as 36.67% (wt) for catalytic pyrolysis at 450ºC. Characterization of physical properties of the resulting pyrolytic oil showed that increase in pyrolysis temperature and CT ratio resulted in higher yield of gas at the expense of oil. When CT ratio is increased from 0.13 to 0.30, the gas yield is increased from 13.33 to 15.33% (wt) and oil yield decreased from 36.67 to 28.0% (wt) at temperature of 450oC. High CT ratio favored an increase in the concentration of light naphtha in the pyrolytic oil. A yield of 97% (wt) is obtained from of the pyrolytic oil at 450oC with CT ratio 0.3 by fractional distillation below 350oC. It could be concluded that after proper treatment these oil can be used as substitute of alternative fuel or chemical feedstock to naphtha.