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This research investigates ethanol production from waste lignocellulosic material (sugarcane bagasse). The bagasse was first pretreated using chemicals and ultrasound techniques. These pretreatment techniques were applied separately and combined. The pretreated bagasse was then fermented anaerobically for biofuel production without enzymatic hydrolysis. The results showed higher ethanol production than those reported in the literature. The maximum ethanol production of 820 mg/L was achieved with a combination of ultrasound (60 amplitude level, 127 W) and acid (3% H2SO4 concentration). The combination of two-step pretreatment such as an ultrasound (50 amplitude level, 109W) with acid (3% H2SO4 concentration) and then an ultrasound with alkaline (23% NaOH concentration) generated 911 mg/L of ethanol. [ABSTRACT FROM AUTHOR]

Homogeneous charge compression ignition (HCCI) engine technology is relatively new and the combustion behavior in an HCCI engine is difficult to predict. The combustion is fully controlled by the chemical kinetics and the chemical reaction of the mixture is influenced by changing input parameters. A zero-dimensional single-zone model was used to investigate the combustion behavior of a diesel engine operating in HCCI mode. An open source chemical kinetics package from Cantera was used in this study. The combustion behaviour can be observed, where H2O2 was fully decomposed during the main combustion event. The time for H2O2 to completely decompose into OH radicals was very short, which was about 5°CA. The combustion phasing was predicted in accordance with the experiment. The auto-ignition can be controlled by controlling the intake temperature or AFR. The start of combustion was advanced by increasing the intake temperature from 20 to 70°C and reducing the AFR from 58 to 29. However, reducing AFR will increase the in-cylinder peak pressure. In general, a zero-dimensional model is a useful and faster tool to predict the combustion phasing. When coupled with chemical kinetics, it provides more accurate results. [ABSTRACT FROM AUTHOR]

Chemical fractionation is a powerful tool for unravelling the reasons behind water treatment problems such as the formation of disinfection by-products (DBPs). This technique can however be costly and time-consuming. Hence, exploring quick affordable surrogate measurements to this technique is of great importance for water treatment operators. In this study, the correlations between aquatic carbon fractions and single wavelength and UV ratios ofA254,A280,A254/A204,A250/A365andA254/A436were examined for seven water bodies located in South-east Queensland, Australia. It was observed thatA254/A204has a strong and significant correlation with hydrophobic/hydrophilic ratio (R2 = 0.984).A250/A365exhibited a weak but significant correlation with the same fraction ratio (R2 = 0.687) suggesting that the chemical fractions cannot be assumed of a certain molecular size.A254/A436had a weak and insignificant correlation with carbon fractions (R2 = 0.0506). The hydrophobic fraction of the seven water bodies showed a strong and significant correlation withA254(R2 = 0.968) andA280(R² = 0.958). The diverse carbon source of the tested water bodies confirms the reliability of the observed correlations. The results of this study highlight the potential use of UV absorbance as a real-time technique for monitoring the structural change of aquatic carbon. [ABSTRACT FROM PUBLISHER]

The deterioration of surface water quality due to extreme weather events and increasing human activities has exacerbated the common problems in drinking water production such as filtration fouling and DPBs formation. This in turn has urged for exploring alternative methods for the traditional treatment methods that are able to improve the removal of contaminants with minimal impact on environment and human health. In this study, the application of pulsed and continuous ultrasound for improving the quality of natural water with fresh natural organic matter (NOM) mainly driven from vegetation has been evaluated. The evaluation was performed using cost-effective and quick measurements such as specific UV–vis absorbance, CODMn, alkalinity and conductivity. The changes in the characteristics of NOM induced by ultrasound were used to develop a framework for evaluating ultrasound performance in improving conventional surface water treatment processes and to identify the best fit of ultrasound within the treatment scheme. Results of this study showed that pulsed ultrasound was as effective as or in some cases better than continuous ultrasound in improving water quality. According to the adapted assessment criteria supported by an extensive literature survey, the most effective location of ultrasound treatment within surface water treatment scheme was found to be prior to coagulation/flocculation. [ABSTRACT FROM PUBLISHER]

In this study, the structural alteration to DOC for a range of ultrasound treatments was investigated with chemical fractionation and UV–vis spectroscopic measurement. Ultrasound treatments were applied in continuous and pulsed modes at power levels of 48 and 84 W for effective treatment times of 5 and 15 min. Overall results show that the ultrasound treatments tended to degrade the hydrophobic aromatic fraction, while increasing the hydrophilic fraction to a lesser extent. The highest recorded reduction of hydrophobic DOC (17.8%) was achieved with pulse treatment of 84 W for15 min, while the highest increase in the hydrophilic DOC (10.5%) was obtained with continuous treatment at 84 W and 5 min. The optimal ultrasound treatment conditions were found to be pulse mode at high power and short treatment time, causing a minimal increase in the hydrophilic fraction of 1.3% with moderate removal of the hydrophobic fraction of 15.52%. The same treatment conditions, with longer treatment time, resulted in the highest removal of SUVA 254 and SUVA 280 of 17.09% and 16.93, respectively. These results indicate the potential for ultrasound treatments in DOC structural alteration. The hydrophobic fraction showed strong and significant correlations with UV absorbance at 254 and 280 nm. A 254 /A 204 also exhibited strong and significant correlations with the hydrophobic/hydrophilic ratio. The other UV ratios (A 250 /A 365 (E 2 /E 3 ) and A 254 /A 436 ) had weak and insignificant correlations with the hydrophobic/hydrophilic ratio. This confirms the applicability of UV indices as a suitable surrogate method for estimating the hydrophobic/hydrophilic structure. [ABSTRACT FROM AUTHOR]

The application of pulsed ultrasound for DOC removal from natural water samples has been thoroughly investigated in this work. Natural water samples were treated with ultrasound at power levels of 48 and 84 W with treatment times of 5 and 15 min. Chemical fractionation was conducted for both untreated and treated samples to clearly identify the change in DOC structure caused by ultrasonic treatments. Statistical analyses applying 2 3 factorial design were performed to study the behaviour of the response (i.e. DOC removal) under different operating conditions. Overall, ultrasonic treatments resulted in DOC removal of 7–15% depending on the applied operating conditions. The treated water had high microbial loading that interfered with DOC removal due primarily to the release of microbial products when exposed to ultrasound. Pulse ultrasound was found to be more effective than the continuous mode for DOC removal at the same effective power level. A regression model was developed and tested for DOC removal prediction. The model was adequate in predicting DOC removal with a maximum deviation from the experimental data of < 11%. Pulsed ultrasound at low power levels and short treatment times was found to be the most energy efficient treatment for DOC removal. [ABSTRACT FROM AUTHOR]

Exhaust pollutants from two-stroke petrol engines are a problem for the environment. Biolubricants are a new generation of renewable and eco-friendly vegetable-based lubricants, which have attracted a lot of attention in recent years. In this paper, the applicability of the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) method to support the process of building the scoring system for selecting an appropriate two-stroke lubricant has been analyzed. For this purpose, biolubricants (TMP-triesters) based on castor oil, palm oil, and waste cooking oil were produced and then utilized in a 200 cc two-stroke gasoline engine to investigate their effects on its performance and exhaust emissions. The results obtained from the use of the entropy technique in the TOPSIS algorithm showed that palm oil-based lubricant took up the greatest distance from the Negative Ideal Solution (NIS) and was selected as the most optimal lubricant for these types of engines. [ABSTRACT FROM AUTHOR]

The household sector consumes a large amount of goods and services and is therefore a major source of global carbon emissions. This study aims to analyze per person household carbon emission (HCEs) patterns of urban and rural China over the period from 1995 to 2011. Annual macroeconomic data for the study were obtained from authentic Chinese government sources. Direct HCE estimates for each fossil fuel were obtained using the IPCC's reference approach, and indirect HCEs were calculated by input-output analysis. In 1995, per person HCEs from direct sources for urban and rural China were 0.50 tCO2 and 0.22 tCO2, respectively; by 2011, these values had increased to 0.60 tCO2 and 0.61 tCO2, an increase of 20% and 177.27%, respectively. Similarly, in 1995, per person HCEs from indirect sources for urban and rural China were 0.43 tCO2 and 0.16 tCO2, respectively; by 2011, these values had increased to 1.77 tCO2 and 0.53 tCO2, respectively, an increase of 306% and 235%. The reasons for these differences and the sets of policies required to rectify increasing emissions are discussed. If current trends and practices continue, with a RMB1000 increase in per capita income from 2011 levels, per person HCEs in urban and rural China will increase by 0.119 tCO2 and 0.197 tCO2, respectively. This result indicates that the sector of society which is most vulnerable will contribute most to China's increasing HCEs. Therefore, while developing energy consumption and emissions reduction policies and programs, principles of fairness and equity need to be followed. [ABSTRACT FROM AUTHOR]

Ultrasound is one of the mechanical methods used for disruption of microorganisms. Ultrasonic treatments of microorganisms are sensitive to a wide range of parameters such as net thermal power, residence time distribution (RTD), and the biological structure of the target microorganism. A commercial ultrasonic processor attached to a stainless steel processing cell was used in this research work. To evaluate the net heat dissipated in a small volume of the commercial yeast Saccharomyces cerevisiae, the suspension was subjected to 117 W at 20 kHz; the ultrasound cell was operated in a batch configuration with a Perspex base. Mixing of the yeast suspension and the RTD were evaluated using image processing techniques. The results of the present study showed that the heat lost through the stainless steel wall, Perspex base, and the Sonotrode (Titanium) was around 13.5 % of the total power. The yeast disruption results were found to be positive. The yeast disruption test showed that complete yeast reduction can be achieved at 117 W and a specific energy of 1,146 kJ kg. Further study is needed to understand the real causes of microorganism disruption using ultrasound. [ABSTRACT FROM AUTHOR]

With consideration of the biomass energy potential, a gamma type Stirling engine with 220cc swept volume and 580cc total volume was designed, optimized and manufactured. The engine was tested with helium. Working characteristics of the engine were obtained within the range of heat source temperature 370- 410˚C and charge pressure 10 bar for biomass resources and heat source temperature 540- 560 ˚C and range of charge pressure 1-12 bar with 1 bar increments at each stage for gases. By using of thermodynamic and heat transfer design methods, the key parameters of the designed Stirling engine like required surfaces for heat transfer were calculated (hot side 307 and the cold side 243 squares of centimeters). For analysis of fluid flow, two-dimensional flow analysis method was performed by the software CFD methods. The principles of thermodynamics as well as Schmidt theory were adapted to use for modeling the engine and then pressure - volume diagrams of the thermodynamic and Schmidt analysis were compared. During the test, the temperature is monitored by thermocouples and the pressure of the working fluid helium is monitored by pressure sensors. Indicated power, friction power and brake power were measured and maximum brake power output was obtained with helium at 550˚C heat source temperature and 10 bar charge pressure at 700 rpm as 96.7 W. Electrical energy produced from biomass sources. Sugarcane bagasse, wood, wheat straw, poplar wood and sawdust as fuel system were selected. Most power be obtained from the sawdust (46 watt) and pruning of trees for wood for low power (21 watts), respectively. Minimum ignition time of the Sawdust (4 min) and the most time flammable wood from pruned trees (10 min) was measured. At maximum power, the internal thermal efficiency of the engine was measured as 16%. The test results confirm the fact that Stirling engines driven by temperature of biomass gases are able to achieve a valuable output power. Results of the present work encouraged initiating design of a single cylinder, gamma type Stirling engine of 1 kWe capacity for rural electrification. [ABSTRACT FROM AUTHOR]

In this research study, a Micro-scale Combined Heat and Power (MCHP) plant with a stirling engine for biomass fuels was developed and optimized. The nominal electric power output of the plant is 100 Watt. Currently this plant has run using wood powder as fuel. With consideration of the biomass energy potential, a gamma type Stirling engine with 220cc swept volume and 580cc total volume was designed, optimized and manufactured. The performance is investigated with regard to the operating conditions, the heat fluxes, temperatures and the type of biomass. Electrical energy produced from biomass sources. The results shows that the highest efficiency of the system is reached for moderate speed values of stirling engine approximately 500-600 rpm. Sugarcane bagasse, wood, wheat straw, poplar wood and sawdust as fuel system were selected. Most power be obtained from the sawdust (46 watt) and pruning of trees for wood for low power (21 watts), respectively. Minimum ignition time of the Sawdust (4 min) and the most time flammable wood from pruned trees (10 min) was measured. At maximum power, the internal thermal efficiency of the engine was measured as 16%. The test results confirm the fact that Stirling engines driven by temperature of biomass gases are able to achieve a valuable output power. Results of the present work encouraged initiating design of a MCHP system with 1 kWe capacity for rural electrification. So this operation can be considered as a breakthrough in the utilization of stirling engine for micro-scale CHP plants utilizing wood powder fuels. [ABSTRACT FROM AUTHOR]

Energy characterization of a pulsed ultrasonic system was carried out using a modified calorimetric method. Sonochemical efficiency (SE) for the oxidation of Fe +2 and the formation of H 2 O 2 was determined for selected on:off ratios ( R ) and different power levels. The measured efficiency of the pulsed ultrasonic system of 60-70% in converting electrical energy into calorimetric energy was found to be constant for all R ratios and equivalent to that for continuous operation. SE of Fe +2 and H 2 O 2 for pulsed ultrasound was higher than that of continuous ultrasound. The ratio R =0.2:0.1 had the highest SE values overall, while for long off-timeratios, R =0.1:0.6 recorded the highest value of SE. These results were supported by the production rates results for Fe +2 and H 2 O 2 . [ABSTRACT FROM AUTHOR]

Increasing global population in present years means more vehicle ownership which leads to the increasing of oxides of nitrogen (NOx) and greenhouse gas emission. Oxides of nitrogen (NOx) are produced from the fuels which burned at high temperatures; contributes to the formation of ozone smog, harmful unseen particles, acid rain, and oxygen depletion that reduced the water quality. The use of higher oxygenated nature biodiesel as an alternative fuel also contributes to the increasing formation levels of NOx emission. In respond to the matters arise, exhaust gas recirculation (EGR) has been introduced to control NOx emissions from diesel engines effectively which lowers the oxygen concentration in the combustion chamber. In this paper, an experimental study was conducted on a Mitsubishi 4D68 four stroke, water cooled DI diesel engine fuelled with neat palm-biodiesel operating with diaphragm exhaust gas recirculation (EGR). Both biodiesel fuel and EGR are employed together to evaluate the engine performance and exhaust emission particularly NOx content. Tests were performed under a steady state condition where conventional diesel fuel was used as a baseline fuel. According to the experimental results, diesel engine operating with palm-biodiesel and EGR reduced the brake power output, decreased the engine torque, increased fuel consumption, decreased NOx and absolute slight increment in other emissions include CO 2 , CO, and particulate matters. [ABSTRACT FROM AUTHOR]

Increasing global population in present years means more vehicle ownership which leads to the increasing of oxides of nitrogen (NOx) and greenhouse gas emission. Oxides of nitrogen (NOx) are produced from the fuels which burned at high temperatures; contributes to the formation of ozone smog, harmful unseen particles, acid rain, and oxygen depletion that reduced the water quality. The use of higher oxygenated nature biodiesel as an alternative fuel also contributes to the increasing formation levels of NOx emission. In respond to the matters arise, exhaust gas recirculation (EGR) has been introduced to control NOx emissions from diesel engines effectively which lowers the oxygen concentration in the combustion chamber. In this paper, an experimental study was conducted on a Mitsubishi 4D68 four stroke, water cooled DI diesel engine fuelled with neat palm-biodiesel operating with diaphragm exhaust gas recirculation (EGR). Both biodiesel fuel and EGR are employed together to evaluate the engine performance and exhaust emission particularly NOx content. Tests were performed under a steady state condition where conventional diesel fuel was used as a baseline fuel. According to the experimental results, diesel engine operating with palmbiodiesel and EGR reduced the brake power output, decreased the engine torque, increased fuel consumption, decreased NOx and absolute slight increment in other emissions include CO2, CO, and particulate matters. [ABSTRACT FROM AUTHOR]