Totally found 184 items.

  • [期刊] Thermochemical conversion of waste engine oil (WEO) to gasoline?rich crude oil
    Thermolysis of Waste Engine oil (WEO) was performed in a semi-batch reactor in the temperature range of 450–575 ℃. The highest yield of pyrolytic oil was obtained (76.73%) at 550 ℃ temperature. The comparative study between the thermogravimetric analysis (TGA) and pyrolysis experiment disclosed that the conversion of WEO was 99.34% in TGA and 98.23% in pyrolysis experiment. The fuel properties such as density (795 g cc~(?1)), calorific value (42.40 MJ kg~(?1)), and flash point (33 ℃) of the pyrolytic oil were less compared to petrol. The decrease in the concentration of Ca, Fe, Mg, Ni, Pb, As, Mn, Zn, and Cu in the pyrolytic oil compared to WEO was perceived. The transformation in the chemical compositions in the pyrolytic oil during the course of pyrolysis was noticed. The pyrolytic oil had a composition of 38% aromatics, 32.97% alkanes, 7.97% cyclo-alkanes, 11.9% alkenes, and 4.78% poly-aromatic hydrocarbons compounds was lower than that of WEO. The WEO pyrolytic oil was containing 65% of gasoline ranged hydrocarbon compounds (C9–C12) along with 24.53% of kerosene (C11–C15), 7.47% of diesel (C15–C19), and 15.32% of heavy fuel oil (? C19).
  • [期刊] The use of waste diversion indices on the analysis of Canadian waste management models
    The performance of non-hazardous waste diversion models were examined in four Western Canadian provinces: British Columbia, Alberta, Saskatchewan, and Manitoba. Between 1998 and 2014, economic outputs, expenditure and profits, and business sizes for both public and private waste services were studied. Three novel indicators were proposed: Waste Management Output Index, Diversion-GDP ratio, and Diversion-Expenditure ratio. British Columbia had the highest overall average diversion rate of 32.7%, while Alberta had the lowest non-residential diversion rate, despite private waste businesses making exceptional profit. Diversion rates alone failed to adequately describe the performance of Canadian waste management systems. The Waste Management Output Index increased with time in all provinces, suggesting the importance of economical outputs from waste management services. Results from the Diversion-GDP ratio showed that higher economic outputs did not appear to have an equally significant impact on diversion. Cost-effectiveness of the systems as measured by the Diversion-Expenditure ratio was constant or slightly declining over the study period. Investigation regarding profit revealed differences between the government and business sectors. Private firms increased in Alberta, doubling between 1998 and 2014. The results of this study highlight the potential benefits of the proposed indices on the evaluation of waste management systems.
  • [期刊] Sugarcane bagasse fiber as semi-reinforcement filler in natural rubber composite sandals
    In many countries, agricultural wastes cause significant air pollution due owing the burning of large amounts of residue. Biocomposites represent a new generation of materials that are eco-friendly, CO2-neutral, economical, low-density and non-petroleum derivatives. They have been widely used to facilitate the reuse of waste and protect the environment. Here, we introduce the reuse of sugarcane bagasse fiber, untreated (SCBU) and alkaline treated (SCBT) by incorporation as reinforcement filler in natural rubber composites used in the manufacture of sandals. Composites were prepared using untreated residue and compared with those treated with 10% sodium hydroxide. The alkali treatment allowed to incorporate high amounts of residue without loss of mechanical properties. The alkali treatment decreased 20% of hardness, increased 98% of tensile strength, maintained the flexibility of the rubber composites, increasing elongation at break to 546% (treated) from 303% (untreated), comparing 40 phr of residue. The composite was used in the preparation of sandals adhering to requirements specified in Testing and Research Institute for the Manufacture of Footwear and paves the way for technological innovation in footwear.
  • [期刊] Properties and potential use of biochars from residues of two rice varieties, Japanese Koshihikari and Vietnamese IR50404
    Converting rice straw or rice husk into biochars is one of the most effective ways to reuse them. This study examined the effect of rice variety and pyrolysis temperature on the properties of biochars, produced from rice straw and rice husk of Koshihikari (a typical rice variety of Japan) and IR50404 (a typical rice variety of Vietnam), in the temperature range from 300 to 800 degrees C. Biochars produced at high pyrolysis temperatures (>500 degrees C) showed higher surface area (approximately 3 times) and higher Si content (by more than 15%), but lower H/C and O/C ratios in comparison with biochars produced at lower temperature. With regard to rice variety, Japanese Koshihikari biochars possessed higher Si content (almost 20%), but lower specific surface area and O/C and H/C ratios than Vietnamese IR50404 rice residue biochars. The surface area of Vietnamese-rice-straw biochars at 600 and 700 degrees C was 30% more than Japanese-rice-straw biochars, while the surface area of Vietnamese-rice-husk biochars was slightly more than that of Japanese-rice-husk biochars. Higher Si content in Japanese Koshihikari biochars was predicted as one of the main reasons for the lower surface area in their biochars, due to the higher possibility of pore-filling or blocking by silica.
  • [期刊] Conversion of de-ashed cocoa pod husk into high-surface-area microporous carbon materials by CO_2 physical activation
    In this work, the de-ashed cocoa pod husk (CPH) was reused as an excellent precursor for preparing high-surface-area activated carbons (ACs) by physical activation with carbon dioxide (CO2) as a gasifying agent. A series of experiments were accomplished at different activation temperatures (i.e., 600, 700, 800, and 900 degrees C) and holding times (i.e., 0, 30, 60, 90, and 120min). Results indicated that the yields of the resulting ACs showed a decreasing trend with increasing both the activation temperature and holding time, but their pore properties and true densities led to an increasing trend. The lowest yield (about 10wt%) was obtained at 900 degrees C for holding 120min, showing that the resulting AC had the highest Brunauer-Emmet-Teller (BET) surface area (over 1300m(2)/g). Furthermore, the resulting ACs were mainly microporous based on the Type I of the nitrogen (N-2) adsorption-desorption isotherms. On the other hand, the chemical compositions of the resulting ACs contained about 88wt% carbon, 8wt% oxygen and 3-4wt% hydrogen/nitrogen/sulfur according to the elemental analysis and scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS).
  • [期刊] Thermal processing of waste tires with heavy oil residue in the presence of Tayzhuzgen zeolite
    A thermal processing of waste tires in the presence of a natural zeolite catalyst from the Tayzhuzgen field (Eastern Kazakhstan) is detailed. The hydrogen sources utilized were heavy residues from oil refinement. The elemental and phase composition of the catalyst and its surface structure were characterized by scanning electron microscopy and X-ray diffraction analysis. The waste tire sample was also studied by thermal gravimetric analysis. It was determined that the SiO2:Al2O3 ratio of 4.57:1 for the natural zeolite refers to clinoptilolite mineral. The use of the Tayzhuzgen zeolite in the thermal processing of waste tires has the following advantages, such as low process temperature, low amount of catalyst and high yield of liquid products compared to other published thermal catalytic methods. The composition of liquid products was found using gas chromatography with mass spectrometric detection. It was concluded that the liquid product obtained by thermal catalytic processing of waste tires with heavy oil residue in the presence of the Tayzhuzgen zeolite, can be used not only as a fuel but also as a raw material for obtaining alkylbenzene compounds.
  • [期刊] Manufacturing of green building brick: recycling of waste for construction purpose
    This study aims to investigate the use of different wastes as raw materials in the fabrication of sustainable, eco-friendly fired building bricks. Wastes such as demolished bricks, fly ash and rice husk ash (RHA) are used for the development of fired building bricks. Based upon partial replacement of clay by demolished brick waste (5-25wt%), various samples are prepared with different compositions and the total waste is kept up to 80 wt%. The effect of glass cullet addition on the sintering temperature and properties of fired bricks are also studied. The samples are prepared by the semi-dry process and fired at different temperatures, i.e., 800, 900 and 1000 degrees C in air atmosphere. All the fired specimens are characterized mainly by physical, mechanical and thermal characterizations. The compressive strength and water absorption are compared with their respective American society for testing materials (ASTM) standards. Results exhibit that 10 wt% glass cullet and 70 wt% other waste demonstrate better properties at 800 degrees C. These promising results suggest that this study will be open a new window to brick industry for utilization of demolished bricks in commercial production of fired bricks.
  • [期刊] Analysis of the feasibility of fruit and vegetable wastes for methane yield using different substrate to inoculum ratios at Hyderabad, Sindh, Pakistan
    The existing disposal method of fruit and vegetable wastes along with other waste has degraded the urban environment of Pakistan. This study was carried out which analyzes the feasibility of fruit and vegetable wastes for methane generation. From vegetable markets and fruit shops, the samples of fruit and vegetable waste were collected, respectively, by standard methodology. After collection, samples were analyzed for pH, alkalinity, volatile fatty acids, lignin content and proximate as well as ultimate analysis. Methane potential of fruit and vegetable wastes was found in the range of 265-444Nml/gVS and 248-471Nml/gVS, respectively. Also, the effect of substrate to inoculum ratio was studied. Findings of study led to conclude that maximum methane production from fruit and vegetable wastes could be achieved using lower substrate to inoculum ratio and vice versa. Therefore, it is recommended that dumping of fruit and vegetable wastes with other waste should be banned in Pakistan. Also the government of Pakistan should take a step immediately for mechanizing a system to separate biodegradable waste at source of generation for methane production.
  • [期刊] Co-plasma processing of banana peduncle with phosphogypsum waste for production of lesser toxic potassium–sulfur rich biochar
    Production of macro-nutrientrich biochar is important to broaden its use as soil fertilizer. In this work, we report production of potassium-sulfurrich biochar through co-plasma processing of banana peduncle biomass with phosphogypsum waste. Biochars were produced using indigenous low-power (15kW) extended arc thermal plasma reactor in 7min under three different plasmagen gases i.e., argon, oxygen, and ammonia. Plasmagen gases showed differential and significant effect on potassium, sulfur and toxic element contents of biochar. Biochars showed relatively higher potassium (4.2-12.7%) and sulfur (13.3-17.8%) contents than phosphogypsum (potassium -0.02% and sulfur -12.5%). In addition, leachable fraction of fluoride and heavy metals decreases in biochars. Among plasmagen gases, retention of potassium and sulfur content was relatively higher in argon, whereas fluoride and heavy-metal leaching reduced maximum in ammonia. X-ray diffraction analysis showed the presence of potassium and sulfur as K2SO4 and CaS minerals in biochars. These findings highlights about application of co-plasma processing of nutrient-rich biomass with phosphogypsum waste for production of lesser toxic nutrient-rich biochar.
  • [期刊] Challenges and opportunities for the recycling industry in developing countries: the case of Sri Lanka
    The paper identifies why the recycling industry is deficient in Sri Lanka from the viewpoint of the integrated sustainable waste management model (ISWMM). ISWMM identifies from a broad perspective the complex and multi-dimensional challenges and solutions in the recycling industries in developing countries. The focus of this study is on all types of recyclable waste generated by all the actors in a developing economy well beyond the commonly focused municipal solid waste. Data were collected from interviews, document analysis and site visits. The challenges for the recycling industry stem from various upstream and downstream actors in the recycling value chain (broadly stakeholders), waste system stages and enabling environment. Sri Lanka, far from being a circular economy, faces many social, environmental, and economic problems. They need remedial action based on these challenges through awareness creation, capacity building, investment in infrastructure and technology, law enforcement and policy implementation, international collaboration, private-public partnership, fiscal policy support, and industry formalization. Thus, the solutions call for a multi-faceted and all stakeholder-inclusive approach.