“…SBE can be produced from clearing unit (the fifth stage of purification of used motor oil). According to an initial estimation and oil absorption, the size of filtered clay particles increases after bleaching process and pollutants absorption [10]. In fact, about 80 to 140 kg of filtered clay per ton of refined used oil is generated in this process.…”
Bleaching earth refers to natural or activated clay which has the capacity to adsorb colored materials and other impurities during oil purification processes. This research utilized the spent bleaching earth (SBE) in used motor oil purification process via thermal remediation (650 ˚C) and acid washing methods (1 M HCl). Then, the activated spent bleaching earth (ASBE) was characterized. The results obtained from the BET analysis show the specific surface area and pore volume of the ASBE, activated virgin bleaching earth (AVBE) and virgin bleaching earth (VBE). These parameters are 100.38 m2g-1 and 0.23 cm3g-1 for the activated spent bleaching earth, 100.82 m2g-1 and 0.22 cm3g-1 for the activated virgin bleaching earth and 83.34 m2g-1 and 0.19 cm3g-1 for the virgin bleaching earth. The BJH analysis indicates that SBE activation increases mesopores in ASBE. In addition, results obtained from the XRD and FTIR tests illustrate that activation of SBE does not affect the physical and chemical properties of montmorillonite clay. Furthermore, SEM observations indicate surface morphology improvement in ASBE. Hence, activation of earth enhances its adsorption efficiency in comparison with virgin bleaching earth.
“…SBE can be produced from clearing unit (the fifth stage of purification of used motor oil). According to an initial estimation and oil absorption, the size of filtered clay particles increases after bleaching process and pollutants absorption [10]. In fact, about 80 to 140 kg of filtered clay per ton of refined used oil is generated in this process.…”
Bleaching earth refers to natural or activated clay which has the capacity to adsorb colored materials and other impurities during oil purification processes. This research utilized the spent bleaching earth (SBE) in used motor oil purification process via thermal remediation (650 ˚C) and acid washing methods (1 M HCl). Then, the activated spent bleaching earth (ASBE) was characterized. The results obtained from the BET analysis show the specific surface area and pore volume of the ASBE, activated virgin bleaching earth (AVBE) and virgin bleaching earth (VBE). These parameters are 100.38 m2g-1 and 0.23 cm3g-1 for the activated spent bleaching earth, 100.82 m2g-1 and 0.22 cm3g-1 for the activated virgin bleaching earth and 83.34 m2g-1 and 0.19 cm3g-1 for the virgin bleaching earth. The BJH analysis indicates that SBE activation increases mesopores in ASBE. In addition, results obtained from the XRD and FTIR tests illustrate that activation of SBE does not affect the physical and chemical properties of montmorillonite clay. Furthermore, SEM observations indicate surface morphology improvement in ASBE. Hence, activation of earth enhances its adsorption efficiency in comparison with virgin bleaching earth.
“…For example, in Shanghai, WCO is collected to produce 35,000 tons of biodiesel annually. In 2014, for urban buses, it is estimated to have reduced 90% of greenhouse gases and 46% of PM 2.5 emissions per 100 km driven by busses [14]. Nevertheless, despite the feasibility, eco‐friendliness and financial support, the application of WCO biodiesel is likely hindered by the lack of specialised gas station, as well as misgivings from bus companies.…”
“…)Figure 5GWP of second-generation biodiesel. Based on data from [20,47,89,90,97,108,164–189]. The negative values are due to the credits for co-products.…”
Section: Environmental Impacts Of Biofuelsmentioning
Biofuels are being promoted as a low-carbon alternative to fossil fuels as they could help to reduce greenhouse gas (GHG) emissions and the related climate change impact from transport. However, there are also concerns that their wider deployment could lead to unintended environmental consequences. Numerous life cycle assessment (LCA) studies have considered the climate change and other environmental impacts of biofuels. However, their findings are often conflicting, with a wide variation in the estimates. Thus, the aim of this paper is to review and analyse the latest available evidence to provide a greater clarity and understanding of the environmental impacts of different liquid biofuels. It is evident from the review that the outcomes of LCA studies are highly situational and dependent on many factors, including the type of feedstock, production routes, data variations and methodological choices. Despite this, the existing evidence suggests that, if no land-use change (LUC) is involved, first-generation biofuels can—on average—have lower GHG emissions than fossil fuels, but the reductions for most feedstocks are insufficient to meet the GHG savings required by the EU Renewable Energy Directive (RED). However, second-generation biofuels have, in general, a greater potential to reduce the emissions, provided there is no LUC. Third-generation biofuels do not represent a feasible option at present state of development as their GHG emissions are higher than those from fossil fuels. As also discussed in the paper, several studies show that reductions in GHG emissions from biofuels are achieved at the expense of other impacts, such as acidification, eutrophication, water footprint and biodiversity loss. The paper also investigates the key methodological aspects and sources of uncertainty in the LCA of biofuels and provides recommendations to address these issues.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
