Springer Science and Business Media LLC

The study presented the blends of waste vegetable oil with kerosene (K-WVO) as diesel substitutes. Three K-WVO blends containing 0.20, 0.35, and 0.50 fraction of WVO in kerosene are comprehensively analyzed for combustion, performance, emissions, economics, and environmental impacts. The engine performance and combustion profiles of the blends were comparable to that of diesel. The blend containing 0.20 fraction as WVO demonstrated better fuel consumption and combustion efficiency than diesel. K-WVO blends showed lower specific carbon monoxide emissions but higher unburnt hydrocarbon emissions relative to diesel. The emission of nitrogen oxide was similar for the blend fuels and diesel. The blends were found to be much economic than diesel. A 52–61% reduction in running cost can be achieved by substituting diesel with a K-WVO blend. The blends with higher WVO fraction are found to be more economic. The use of K-WVO blends can be expected to lower the global warming potential by 19.6–21% compared to diesel fuel. Largely, the blend fuels were found to have lower environmental impacts compared to diesel. The study showed that the benefits associated with a blend depend on blend composition. The blend with a lower WVO content can have better engine performance and emission characteristics, but blend with a higher WVO has more economic and environmental benefits. Thus, the comprehensive assessment presented in the study can be used as a guide toward defining the proper WVO-kerosene blend composition based on the proposed objective.

The paper deals with the elimination of highly toxic and persistent relict burdens caused by polychlorinated dibenzo-p-dioxins, dibenzofurans, biphenyls, hexachlorobenzene, γ-isomer of hexachlorocyclohexane and other organic halogen derivatives. The technology is used in eliminating the aforementioned contaminants from soil, rubble and metal parts of former machinery with the use of best available techniques. Such a technology has been implemented in the northern part of the town of Neratovice and the Spolana company, plc, which formerly used to be a significant producer of pesticides in the Czech Republic.

Industrial research generally focuses on developing sustainable processes through environmentally friendly processes and chemicals. The leather sector receives a lot of attention on account of being intensive in the use of water and chemicals. The liming/fiber opening process in the pre-tanning stage consume a high amount of water and chemicals. Eventually, this process results in generation of wastewater with high biological oxygen demand (BOD), chemical oxygen demand (COD), and total dissolved solids (TDS). The present study focuses on the sustainable fiber opening process using supercritical carbon dioxide (SCCO2) to reduce pollution by minimizing chemical and water usage. The designed SCCO2 fiber opening process is entirely free of chemical additives and water. And, the process condition is optimized at 75 bar for 30 mins, where the conventional liming process serves as a control. The CO2 diffuses into the skin matrix and opens the fiber bundles through physical modification. Hence, the SCCO2 fiber opening process does not require chemicals and water, thus results in zero pollution loads. Further, the experimental fiber opened samples exhibited enhanced porosity compared to control, where the control and experimental sample mean value was 20.58 cm3/s and 54.04 cm3/s, respectively, at a maximum 75 psi pressure. Fiber opening efficacy of SCCO2 experimental trials was further substantiated based on the scanning electron microscopic analysis. Additionally, processed leather has improved organoleptic and physical strength characteristics. According to the study, using SCCO2 in the fiber opening process can result in an environmentally friendly process by reducing pollution, chemical use, and time.

The majority of rural communities in developing countries (such as Peru) are not connected to the electrical grid. Hybrid energy production from available renewable resources (e.g., wind and solar) and diesel engines is considered as an economically viable and environmentally friendly alternative for electrification in these areas. Motivated by the lack of a comprehensive investigation dedicated to the techno-economic analysis of hybrid systems (PV–wind–diesel) for off-grid electrification in Peru, the present work is focused on determining the optimal configuration of these systems for remote Peruvian villages. Three small communities without access to the grid (Campo serio, El potrero, and Silicucho), which are located in different climatic zones of Peru, have been accordingly selected as case studies. Seven different configurations including single component systems (solar, wind, and diesel) and hybrid ones are considered. While taking into account the meteorological data and load characteristics of the communities along with the diesel fuel’s price and the cost of components, HOMER software is utilized to determine the optimal sizing of the system [resulting in the lowest net present cost (NPC)] considering different scenarios. The obtained configurations are then compared considering other state-of-the-art economic indices [initial capital cost, total annual operating cost, and the cost of energy (COE)], the generation fractions, and the resulting CO2 emissions. The obtained results have revealed that, for all of the investigated communities, the hybrid solar–wind–diesel system is the most economically viable scenario. Considering the latter scenario, the obtained optimal configuration leads to an NPC of USD 227,335 (COE: 0.478 USD/kWh) for Campo serio, USD 183,851 (COE: 0.460 USD/kWh) for El potrero, and USD 146,583 (COE: 0.504 USD/kWh) for Silicucho. Furthermore, employing the optimal configurations a renewable fraction (with respect to the total generation) of 94% is obtained for Campo serio and Silicucho, while the achieved renewable fraction for El potrero is 97%. Moreover, for the case of Campo serio, the resulting CO2 emission of the obtained optimal system is determined to be 6.1% of that of a diesel-only unit, while the latter ratio is determined to be 2.7% for El potrero and 9.9% for that of Silicucho. The optimal configurations that are obtained and presented in the present paper can be utilized as guideline for designing electrification systems (with a minimized cost) for the considered communities and other villages with similar characteristics (population and climatic conditions).

Carbon dioxide emission, which acts as one of the major agents of greenhouse gases (GHG), has significant effects on global warming. Nowadays, there is a considerable global tendency toward decreasing the amount of GHG emissions to the atmosphere. In the present study, a simulated power plant flue gas (Be’sat, Power Plant, Tehran) with a constant injection rate of 21.41 cm3 s−1, including 10% CO2, 7% O2 and 83% N2 , was injected to the Synechococcus elongatus culture under two different light–dark (L/D) cycles: 24-0 and 16-8. Additionally, the biomass productivity and the CO2 biofixation rate by microorganisms were investigated. The highest biomass productivities were recorded as 0.68 and 0.52 g L−1 d−1 for 24-0 and 16-8 L/D cycles, respectively. Furthermore, the maximum rate of the CO2 biofixation was 1.26 g L−1 d−1 for the 24-0 L/D cycle and 0.98 g L−1 d−1 for the 16-8 L/D cycle during the cultivation.