| 1. |
- Bajwa, Anjali, et al.
(författare)
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Activated Carbon Monoliths by Pressureless Technique for Environmental Applications
- 2015
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Ingår i: Environmental Progress & Sustainable Energy. - : Wiley. - 1944-7442 .- 1944-7450. ; 34:5, s. 1420-1426
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Tidskriftsartikel (refereegranskat)abstract
- Carbon monoliths have been prepared through simple procedure by carbonization in inert atmosphere at 550 C from commercial activated carbon and from unburned carbon in it ykste bctgasse fly asb; US nig, In 0 different kin dS phenolic resin binders. The bagasse fly ash was collected ft on; sugar mills where bagasse is used as a biomass based fuel for cogeneration. Commercial actuated carbon based monoliths whet -e 5 and 10 wt % of the actuated carbon had been replaced by iron oxide (hematite) were dic0 prepared. Results indicate that BET sutfac:e area decreases upon carbonization and loading of hematite. Scanning electron microscopy studies shows that the iron oxide is well distributed over the monoliths and X-ray diffraction shows that it is reduced to magnetite during carbonization. Temperature programmed reduction eAperintents show that the iron oxides on the monoliths are redox active. The monoliths based on commercial activated carbon show 80% remotwl of phenol in dihtted phenol based water solutions whereas unburned carbon derived monoliths showed 5-/ % removal in similar solution.
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| 2. |
- Carlsson, Per, et al.
(författare)
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Spatially resolved measurements of gas composition in a pressurised black liquor gasifier
- 2009
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Ingår i: Environmental Progress & Sustainable Energy. - : Wiley. - 1944-7442 .- 1944-7450. ; 28:3, s. 316-323
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Tidskriftsartikel (refereegranskat)abstract
- Black liquor gasification is a new process for recovery of energy and chemicals in black liquor from the Kraft pulping process. The process can be combined with catalytic conversion of syngas into motor fuels. The potential for motor fuel production from black liquor in Sweden is to replace about 25% of the current consumption ofgasoline and diesel. For Finland the figure is even higher while for Canada it is about 14% and for the USA about 2%. © 2009 American Institute of Chemical Engineers Environ Prog, 28: 316-323, 2009.
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| 3. |
- Daneshvar, E., et al.
(författare)
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Biosorption and Bioaccumulation Studies of Acid Orange 7 Dye by Ceratophylum demersum
- 2013
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Ingår i: Environmental Progress & Sustainable Energy. - : Wiley. - 1944-7442 .- 1944-7450. ; 32:2, s. 285-293
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Tidskriftsartikel (refereegranskat)abstract
- Biosorption and bioaccumulation studies of acid orange 7 (AO7) dye by an aquatic plant, C. demersum, were investigated in the present work. The effects of different parameters such as, initial solution pH (2–11), initial dye concentration (30–90 mg/L), contact time (5–150 min), biomass dosage (1.8–23.4 g/L for living and 0.2–2.6 g/L for nonliving or dried plant) and salt concentration (0.5–20 g/L) on the decolorization of AO7 dye were investigated by batch method. The efficiency of both leaf and stem of the living plant was also assessed for the dye removal. Living plant of C. demersum exhibited higher decolorization potential as compared with the dried plant which might be attributed to the active metabolism of the former. The sorption kinetic data were successfully described with pseudo-second order model for living and dried plant. Thermodynamic studies revealed that the sorption process is endothermic in nature at studied temperature range of 283–313 K. These findings revealed that aquatic plant, C. demersum, can be a suitable alternative for decolorization of AO7 dye from aqueous solution.
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| 4. |
- Landälv, Ingvar, et al.
(författare)
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Two years experience of the BioDME project : A complete wood to wheel concept
- 2014
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Ingår i: Environmental Progress & Sustainable Energy. - : Wiley. - 1944-7442 .- 1944-7450. ; 33:3, s. 744-750
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Tidskriftsartikel (refereegranskat)abstract
- Dimethyl ether (DME), is an excellent diesel fuel that can be produced through gasification from multiple feedstocks. One particularly interesting renewable feedstock is the energy rich by-product from the pulping process called black liquor (BL). The concept of utilizing BL as gasifier feed, converting it via syngas to DME and then compensating the withdrawal of BL energy from the pulp mill by supplying biomass to a conventional combined heat and power plant, is estimated to be one of the most efficient conversion concepts of biomass to a renewable fuel on a well-to-wheel basis. This concept has been demonstrated by the four-year BioDME project, including field tests of DME-fueled heavy-duty trucks that are operated commercially. Up till the summer of 2013 more than 500 tons of BioDME has been produced and distributed to 10 HD trucks, which in total has run more than 1 million km in commercial service
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| 5. |
- Lehtveer, Mariliis, 1983, et al.
(författare)
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Estonian energy supply strategy assessment for 2035 and its vulnerability to climate driven shocks
- 2016
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Ingår i: Environmental Progress and Sustainable Energy. - : Wiley. - 1944-7442 .- 1944-7450. ; 35:2, s. 469-478
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Tidskriftsartikel (refereegranskat)abstract
- Estonia is a relatively small country with a limited supply of indigenous energy resources mainly consisting of oil shale, wood, and peat. Estonia is also the only country in Europe with a dominant electricity production by burning oil shale. Around 90% of the overall electric energy production in Estonia comes from the Narva Power Plants. This presents great challenges and problems due to massive emissions of greenhouse gases into the atmosphere as well as radiological impact on the environment. Therefore, the current energy supply strategy can be considered hazardous and an unpopular choice for future energy system planning. In this article, we analyze the current energy policy as well as inclusion of new strategies to produce electricity for Estonia for a target year of 2035. We use a computer model Model for Supply Strategy Alternatives and their General Environmental Impacts (MESSAGE) to provide optimization and aim in helping the policymakers in the Estonian decision making process. We also add a specific case in the MESSAGE model to examine the ability of the current electricity supply strategy to handle climate related shocks with a special focus on cold weather in two plausible cases; single cold winter and prolonged cold winter. Results indicate that unexpected demand shocks may cause serious losses in gross domestic product (GDP). Therefore, the authors come to the conclusion that extra capacity is highly recommendable for a number of reasons. We also find that nuclear power becomes economically preferable to oil shale with a CO2 tax of Euro20/t. Yet moving toward nuclear or other low CO2 alternatives presents certain challenges. (c) 2015 American Institute of Chemical Engineers Environ Prog, 35: 469-478, 2016
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| 6. |
- Nikjoo, Dariush, 1977-, et al.
(författare)
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Laminated Porous Diatomite Monoliths for Adsorption of Dyes From Water
- 2019
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Ingår i: Environmental Progress & Sustainable Energy. - : John Wiley & Sons. - 1944-7442 .- 1944-7450. ; 38:s1, s. 377-385
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Tidskriftsartikel (refereegranskat)abstract
- Structured laminated diatomite monoliths with superior mechanical properties were prepared by controlled freeze-casting of the aqueous suspensions of diatomite powders for wastewater treatment. The directional freezing of suspensions with solids loading of 25, 30, and 37 wt % at cooling from 0.5 to 5 K/min resulted in the formation of lamellar pores and solid walls with the thickness of 12–30 and 14–39 μm, respectively. The increase in solid loading and freezing rate resulted in refinement of the porous structure. Durable monoliths with the mechanical strength of 5.3 MPa were obtained by thermal treatment of the freeze-dried green bodies at 1,373 K. Diatomite monoliths with a pore size of 29.6 μm showed the removal of model dye pollutant Rhodamine B from water by adsorption and long-term water stability. The dye uptake capacity of monolith changed from 1.38 to 17.04 mg/g for the initial dye concentrations between 1.0 and 12.5 mg/L at 298 K and pH = 6, respectively. The adsorption data analysis using Lagergren's pseudo-first-order, pseudo-second-order, and intra-particle diffusion models revealed that diatomite monoliths offered efficient mass transfer in the porous laminated scaffold and to the adsorption sites and bulk diffusion of dye molecules in water was the rate-limiting mechanism for dye removal. © 2018 American Institute of Chemical Engineers Environ Prog, 2018.
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| 7. |
- Tunå, Per, et al.
(författare)
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Techno-economic assessment of nonfossil ammonia production
- 2014
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Ingår i: Environmental Progress & Sustainable Energy. - : Wiley. - 1944-7450 .- 1944-7442. ; 33:4, s. 1290-1297
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Tidskriftsartikel (refereegranskat)abstract
- The production of nitrogen fertilizers are almost exclusively based on fossil feedstocks such as natural gas and coal. Nitrogen fertilizers are a necessity to maintain the high agricultural production that the world's population currently demands. Ammonia produced from nonfossil-based feedstocks would enable renewable production of ammonia. Renewable feedstocks are one thing, but perhaps even more important in the future are the security of supply that decentralized production enables. In this study, the techno-economic evaluation of production of ammonia from various renewable feedstocks and for several plant sizes was investigated. The feedstocks included in this study are grid-based electricity produced from wind power, biogas, and woody biomass. The feedstocks differed in exergy, and to make a fair comparison, the electric equivalence ratios method was used. The results showed that the energy consumption for biogas and electricity is the same at 42 GJ/tonne ammonia. When using the electric equivalence comparison for the same cases, the results are 26 and 42 GJ/tonne, respectively. Biomass-based production has an energy consumption of 58 GJ/tonne and 31 GJ/tonne when using the electric equivalence comparison, which should be compared with the industrial average of 37 GJ (or 21 GJ electric equivalence) per tonne of ammonia. Monte Carlo simulations were used to vary the inputs to the process to evaluate the production cost. The ammonia production cost ranged from $680 to 2300/tonne ammonia for the various cases studied
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| 8. |
- Welander, Ulrika, 1966-, et al.
(författare)
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Treatment of alpha-pinene contaminated air using biofilters with and without silicone oil
- 2010
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Ingår i: Environmental Progress & Sustainable Energy. - : Wiley InterScience. - 1944-7442 .- 1944-7450. ; 29:3, s. 313-318
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Tidskriftsartikel (refereegranskat)abstract
- Two biofilters equal in size were filled with perlite for treatment of -pinene-contaminated air. The perlite used for one of the biofilters was partially coated with silicone oil to make the surface of the particles more hydrophobic. The filters were run at 1.5, 2.5, and 5 L/min airflow rate (3.1, 1.9, and 0.9-min retention time). The filters were operated for 5.5 months. The results showed that the silicone oil-coated filter performed better at 2.5 L/min with a maximum elimination capacity of 20 g/(m3 h) in comparison with 15 g/(m3 h) for the filter without oil. The efficiency was approximately the same for both filters at 1.5 L/min (40 g/m3 h), whereas it was slightly higher for the without oil filter at 5 L/min [35 g/(m3 h)]. The flow rate was set to 2.5 L/min once more (day 151). The results showed that the elimination capacity had increased to 35 g/(m3 h) and that the efficiency of both filters was approximately the same. The difference in results between the initial run and the later run at 2.5 L/min is probably depending on that the number of microorganisms had increased during the experiment and that the oil-containing biofilter adsorbed -pinene to a higher extent than the biofilter without silicone oil during the start-up period. © 2009 American Institute of Chemical Engineers Environ Prog, 2010
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| 9. |
- Jobby, Renitta, et al.
(författare)
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Differential expression of antioxidant enzymes under arsenic stress in Enterobacter sp.
- 2016
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Ingår i: Environmental Progress & Sustainable Energy. - : Wiley. - 1944-7442. ; 35:6, s. 1642-1645
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Tidskriftsartikel (refereegranskat)abstract
- Arsenic is a major contaminating heavy metal due to its frequent occurrence and toxicity. Out of different remediation approaches, bioremediation using bacteria has been extensively studied. In this study, 29 bacterial isolates were screened for their arsenic tolerance capacity. One of the isolate, MUM2 showed maximum arsenic tolerance (10mM). Antioxidant enzymes were assayed in this isolate under arsenic stress. Although, the CAT activity was found to increase significantly, the SOD activity showed a significant decrease under 9mM arsenic stress. The results obtained suggest a possible role of CAT in combating arsenic stress. Further studies at genetic level would help in developing highly tolerant strains for remediation of arsenic.
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| 10. |
- Mondejar, Maria E., et al.
(författare)
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Analysis of isentropic mixtures for their use as working fluids in organic Rankine cycles
- 2017
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Ingår i: Environmental Progress & Sustainable Energy. - : Wiley. - 1944-7442. ; 36:3, s. 921-935
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Tidskriftsartikel (refereegranskat)abstract
- The selection of appropriate working media for organic Rankine cycles (ORC) is essential for the optimization of their performance. Dry fluids are widely used in existing ORC because, unlike wet fluids, they do not need to be superheated to avoid wet expansion that may cause damage to the expander. However, regeneration is sometimes needed for fluids with a highly dry behavior in order to improve the overall ORC efficiency, at the expense of increasing the total capital costs. On the contrary, isentropic fluids, with a nearly isentropic saturated vapor curve, overcome these two drawbacks. Because the number of single component fluids with isentropic behavior is scarce, we propose the use of isentropic binary mixtures, composed by a wet and a dry component. In this work, we selected several isentropic binary mixtures composed of hydrofluorocarbons, hydrochlorofluorocarbons and hydrocarbons from the Refprop database. The performance of these mixtures was evaluated in a simple saturated ORC model for source temperatures between (350 and 450) K and a fixed sink temperature of 290 K. The results were compared to those yielded by pure isentropic and dry fluids under the same source and sink conditions.
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