Eco-friendly Choice Research Articles

Polyetheramine as an alternative alkali for alkali/surfactant/polymer flooding

The application of conventional alkalis (NaOH or Na2CO3) in alkali/surfactant/polymer (ASP) flooding is rather limited due to their intrinsic drawbacks, including precipitating during injection into formation water with a high divalent ion concentration and enhancing the dispersibility of clays (e.g., montmorillonite (MMT) or kaolinite) in water, which lead to damage to reservoir formations and bring about difficulties in treating produced fluids. Here, we propose polyetheramine D 230 as an alternative alkali to avoid these problems. D 230 is a diamine linked by poly(oxypropylene) backbones. Interfacial tension and emulsification measurements proved that D 230 can neutralize the acidic components in crude oil to generate surface-active soaps, which facilitate oil emulsification in water. Contact angle measurements indicated that an oil-contaminated quartz surface treated with D 230/SP blends was successfully altered from oil-wet to water-wet. Sand pack flooding measurements demonstrated that a D 230/SP injection was able to mobilize 19.23% of the original oil in place (OOIP) after thorough water flooding. Rheograms of alkali/polymer blends showed a reduced impact of D 230 on viscosity. Static bottle tests indicated that no precipitation occurred after D 230 was injected into formation water with a high Ca2+ concentration. Colloidal stability measurements of clay dispersions suggested that D 230 can inhibit clay dispersibility. As an alternative alkali in ASP flooding, D 230 not only facilitates enhanced oil recovery (EOR) but also solves problems such as precipitation, high biotoxicity, reduced fluid viscosity and enhanced clay dispersibility brought about by conventional inorganic and organic alkalis. These advantages make D 230 an eco-friendly choice as an alkali for ASP flooding.

Properties of Concrete Incorporating Coal Fly Ash and Coal Bottom Ash

Million loads of coal wastes are being generated everywhere across the globe in the form of fly ash and bottom ash. Utilization of such waste materials in concrete is an eco-friendly choice. Therefore, the objective of the current experimental investigation is to explore the effects of fly ash and bottom ash on the properties of concrete by replacing them partially with natural fine aggregate and cement, respectively, on an individual basis as well as on combined basis. Concrete specimens are prepared by replacing 0%, 20%, 30%, 40% and 50% of sand by coal bottom ash and 0%, 20%, 30%, 40% and 50% cement by coal fly ash. Thereafter, the concrete specimens are prepared by replacing optimum percentages of both cement and sand by coal fly ash and coal bottom ash, respectively. The compressive strength, split tensile strength, flexural strength and density of the above mixes are obtained from the experimental investigation. From these results, it is found that for concrete mix with 20% coal fly ash and 30% coal bottom ash, the compressive, split tensile and flexural strength reduce by 10.5%, 10.7% and 9.6%, respectively, with reference to those of the control mix. Moreover, for the above concrete mix, the dry density also reduces by 10.3% from the control mix. These properties of the concrete mix with 20% coal fly ash and 30% coal bottom ash are further improved by adding a suitable dose of superplasticizer.

Unveiling algal cultivation using raceway ponds for biodiesel production and its quality assessment

Abstract Microalgal biomass is a renewable, carbon-neutral resource and an excellent alternative to petroleum-footed fuels. In this work the open outdoor raceway pond system was used for the cultivation of Chlorella vulgaris. The biomass productivity was 31.5 mg L-1d-1 and lipid content 25 ± 5% when cultivated in low cost medium (Urea, Superphosphate and Potash at 91.9, 72.9 and 62.7 mg L-1 where the pH was 8.03) formulated by RSM. The highest FAME yield was 67% under the optimized conditions of H2SO4 at 4%; reaction time at 4 h; methanol-hexane as co-solvent in the ratio of 2:1; and temperature at 80 °C for 100 mg of algal lipid. The DU, LCSF, CFPP, CN, PP, CP of the biodiesel evidenced high quality, which corroborate with International standards. The diesel engine performance showed a blend of B50 which is superior in quality compared to B20 and B40 blends and the commercial diesel. Furthermore, reduction of brake-specific fuel consumption at 100% load showed 273.9 g/kW h in B50 whereas for commercial diesel it was 275 g/kW h. There was 40–55% reduction of CO, HC, and emissions compared to commercial diesel. Thus, this research emphasizes that microalga-based biodiesel is cost-effective and eco-friendly choice for biodiesel.

Enabling Eco-Friendly Choices by Relying on the Proportional-Thinking Heuristic

Ecological (eco) taxes are promising mechanisms to enable eco-friendly decisions, but few people prefer them. In this study, we present a way in which eco-tax options may be communicated to general public to encourage their payment. Our implementation (called “information presentation”) takes advantage of the non-linear relationship between eco-tax payments and CO2 emissions and the human reliance on the proportional-thinking heuristic. According to the proportional-thinking heuristic, people are likely to prefer a small eco-tax increase and judge larger eco-tax increases to cause proportionally greater CO2 emissions reductions. In an online study, participants were asked to choose between eco-tax increases in two problems: In one, a smaller eco-tax increase resulted in greater CO2 emissions reduction, while in the other, a smaller tax increase resulted in lesser CO2 emissions reduction. Although the larger eco-tax increase did not reduce CO2 emissions the most, across both problems, people judged larger eco-tax increases to cause proportionally greater reductions in CO2 emissions and preferred smaller tax increases. Thus, eco-tax policies would benefit by presenting information in terms of eco-tax increases, such that smaller eco-tax increases (which are more attractive and are likely to be chosen by people) cause greater CO2 emissions reductions.