• Energy Research
• 7. Clean energy close

An important issue for optimal operation and plantwide control is to find the degrees of freedom available for optimal operation. A previously published systematic approach to determine the steady state degrees of freedom is expanded to take into account the active charge as a possible degree of freedom in cyclic processes. Additional degrees of freedom related to the composition of the circulating refrigerant are also discussed. Two liquified natural gas (LNG) processes of current interest, the C3MR process from Air Products and the mixed fluid cascade (MFC) process developed by Statoil-Linde LNG Technology Alliance, are studied with respect to operational degrees of freedom.

Abstract Canada has numerous climatic and geographical regions and the Canadian housing stock (CHS) is diversified in terms of vintage, geometry, construction materials, envelope, occupancy, energy sources and heating, ventilation and air conditioning system and equipment. Therefore, strategies to achieve net zero energy (NZE) status with the current stock of houses need to be devised considering the unique characteristics of the housing stock, the economic conditions and energy mix available in each region. Identifying and assessing pathways for converting existing houses to NZE buildings at the housing stock level is a complex and multifaceted problem and requires extensive analysis on the impact of energy efficiency and renewable/alternative energy technology retrofits on the energy use and GHG emissions of households. A techno-economic analysis of retrofitting renewable/alternative energy technologies in the CHS to reduce energy consumption and GHG emissions was conducted to develop strategies to achieve or approach NZE status for Canadian houses. The results indicate that substantial energy savings and GHG emission reductions are techno-economically feasible for the CHS through careful selection of retrofit options. While achieving large scale conversion of existing houses to NZEB is not feasible, approaching NZE status is a realistic goal for a large percentage of Canadian houses.

Cold-start (subzero startup) capability of polymer electrolyte fuel cell (PEFC) is of great importance. In this paper, the effects of the micro-porous-layer (MPL), varying start-up temperatures, start-up current density variation on the cold-start operation are investigated. We found PEFC with anode micro-porous-layer (AMPL), compared with one with CMPL, has higher possibility of successful cold start. By analyzing the anode and cathode pressure revolution of PEFC, the effect of MPL on the super cooled water removal and ice formation at different temperatures (-7,-10,-15 and-20℃) are discussed . In addition, we investigate the ice distribution in MEA through the X-ray device, by comparing the initial image when fuel cells shut down (before the produce the water) and final image after failed cold-start. We also explore the negative voltage phenomenon in the initial process of cold-start operation.

Abstract The increasing energy demand in developing countries has jeopardised energy security, necessitating the employment of solar energy to augment conventional energy sources. It is important to assess the annual performance parameters of solar power plants to understand its place in energy generation. This study analyses the performance and economic viability of a large-scale solar power park located in India. A 50 MWp Solar Photovoltaic Power Park (SPPP) located at Sakunala, in the State of Andhra Pradesh, is one of the largest solar power park in India, and the site receives an average solar radiation of 5.5–6.0 kWh/m2/day. The design, performance analysis, economic feasibility, and greenhouse gas mitigation of the 50 MWp SPPP is presented. The energy yields, performance ratio (PR), capacity utilization factor (CUF), and losses are assessed based on the IEC 61724 standards for two consecutive years (2018–2019 and 2019–2020). The performance results obtained are compared with the PVsyst simulation results. The PR, CUF, and energy yields are estimated as 0.779, 0.24, and 107,326.4 MWh in 2018–2019 and 0.691, 0.22, and 96,707.336 MWh in the year 2019–2020, respectively. The PVsyst simulator evaluates the PR, CUF, and energy yields as 0.80, 0.24, and 106,022 MWh, respectively. Further, the effect of power curtailment policies on solar PV projects is also discussed and the effect of curtailment policy on the economy of the solar power park in terms of payback period and emissions are analysed. The performance of the SPPP is also compared with those of other PV plants installed all over the world.

Microbial fuel cell (MFC) is a sustainable and energy efficient technology, which uses graphite as cathode for hydrogen peroxide (H2O2) production often with simultaneous power production. Nevertheless, slow kinetics of oxygen reduction reaction (ORR) at the surface of graphite often results in poor performance of MFC. In an attempt to improve the performance of MFC for in‐situ H2O2 production, a treatment of graphite cathode using nitric acid was performed. The treatment was conducted in three steps (i) heat treatment at 450°C for 2 h; (ii) acid treatment with concentrated nitric acid for 5 h; and (iii) drying at 120°C for 2 h. After the treatment, four times increase in surface area of treated cathode (GR‐HA) was observed. Energy‐dispersive X‐ray spectroscopy (EDX) and Fourier transform infrared (FTIR) analysis revealed the presence of nitrogen and quinone based functional groups on the surface of GR‐HA. Cyclic voltammetric (CV) analysis of GR‐HA cathode further confirmed the production of H2O2 at the peak current value of −3.7 mA and on‐set potential of −0.1 V. Following CV analysis, H2O2 production experiments were performed in a dual chamber MFC using GR‐HA as cathode. Maximum 150 mg/L of H2O2 was produced with simultaneous power production of 36.438 mW/m2. Approximately, 25% increase in both H2O2 and power production was observed in the case of G cathode. Subsequently, Fenton oxidation experiments were performed (with GR‐HA and GR‐CA cathodes) to determine the efficacy of in‐situ produced H2O2. This resulted in an increase of 8.28%, 11.04%, and 31.32% in decolorization, chemical oxygen demand (COD), and Total Organic Carbon (TOC) removal efficiency, respectively. © 2016 American Institute of Chemical Engineers Environ Prog, 36: 382–393, 2017

AbstractThe concept of a ‘just transition’ to a low‐carbon economy is firmly embedded in mainstream global discourses about mitigating climate change. Drawing on Karl Polanyi's political economy elaborated inThe Great Transformation, we interrogate the idea of a just transition and place it within its historical context. We address a major contradiction at the core of global energy transition debates: the rapid shift to low‐carbon energy‐systems will require increased extraction of minerals and metals. In doing so, we argue that extractive industries are energy and carbon‐intensive, and will enlarge and intensify social and ecological injustice. Our findings reveal the importance of understanding how the idea of a just transition is used, and by who, and the type of justice that underpins this concept. We demonstrate the need to ground just transition policies and programmes in a notion of justice as fairness.

Straw and other biomasses can cause severe problems when used as fuel in combustion systems. Some of the major problems include high emission of alkalis, HCl, and especially SO2 to the gas phase. T...

Summary Extraheavy-oil (XHO) reservoirs in South America represent some of the largest hydrocarbon accumulations (>500 billion bbl) in the world. Primary production (PP) that uses long horizontal wells is a commercially proved technology for XHO reservoirs. The expected ultimate recovery with primary production is generally less than 12% of original oil in place (OOIP), and thermal enhanced oil recovery (EOR) is critical for increasing recovery to 30–60% OOIP. Economic and environmentally viable thermal development of these reservoirs will require the use of horizontal steam injectors. Our results reveal that continuous steam injection (CSI) with a horizontal injector placed vertically above a horizontal producer (CSI-HIHP) is a very effective method for XHO reservoirs, with high peak-oil rate and significantly high recovery. This study, the first of its kind for an XHO reservoir, outlines an integrated work flow to evaluate the production potential of a large XHO greenfield with PP followed by thermal exploitation. The work flow, based on a probabilistic framework [involving design of experiment (DOE), proxy methods, and Monte Carlo simulations], evaluates reservoir performance for the whole life cycle of the field under a range of uncertainties, and quantifies the impact of key parameters affecting the reservoir performance. XHO reservoirs usually have significantly higher pressures than typical conventional heavy-oil reservoirs, where CSI has been applied commercially. Therefore, pressure in these reservoirs must be reduced before CSI can begin. Cyclic steam stimulation (CSS) after the initial stage of PP can be used to accelerate pressure reduction in the reservoir, while providing additional recovery. Our results demonstrate that geological features such as shale baffles have a significant impact on delaying pressure reduction during PP and CSS. Under a broad range of conditions investigated in this study, PP for 1 year followed by CSS for 4 years has been found to be successful in reducing pressure to the target pressure for CSI. High pressure drop in the horizontal steam injector can cause pressure near the toe region of the injector to be lower than the producer pressure. This results in poor steam injection and poor steam-chest development in that region, thus greatly reducing the efficiency of the thermal-recovery process. We quantify pressure drop in a horizontal steam injector and its impact on the thermal performance and suggest a novel well configuration that uses two injectors for every long producer during CSI. The proposed configuration with a sequential development plan can significantly improve economics of the projects. A novel probabilistic work flow for a full-field (FF) development plan (PP, CSS, and CSI) of XHO reservoirs provides robust production forecast during the entire life cycle. The work flow developed and the insights obtained would be very valuable in preparing effective exploitation plans and optimal facility design, a key economic variable in large projects of developing giant XHO reservoirs.

{"references": ["Retrieved on April 12, 2013 from website http://www.peakbagger.com/range.aspx?rid=432", "Alexander, Christopher, \"Notes on the Synthesis of Form, 1st ed.\", Harvard University Press, 1964, pp. 1-224.", "Borucke, Michael, David Moore, Gemma Cranston, Kyle Gracey, Katsunori Iha, Joy Larson, Elias Lazarus, Juan Carlos Morales, Mathis Wackernagel, Alessandro Galli, 2012, \"Accounting for demand and supply of the biosphere's regenerative capacity: The National Footprint Accounts' underlying methodology and framework\", Ecological Indicators 24 (2013) 518\u2013533, Elsevier Ltd.", "Adams, W.M., \"The Future of Sustainability: Re-thinking Environment and Development in the Twenty-first Century\", 2006, Report of the IUCN Renowned Thinkers Meeting, 29\u201331 January 2006.", "Abdaei, Kaveh, Ahadollag Azami, \"Sustainability Analyses of Passive Cooling Systems in Iranian Traditional Buildings approaching Wind-Catchers\", Recent Advances in Energy, Environment and Development, pp.124-129.", "Afrasiabian, Shaghayegh, Mohammadjavad Mahdavinejad, Negar Badri, \"Nature as a Source of Sustainable Design in Architecture of Original Countries (Case Study: Traditional Architecture of Iran)\", Archi-Cultural Translations through the Silk Road 2nd International Conference, Mukogawa Women's Univ., Nishinomiya, Japan, July 14-16, 2012 Proceedings, pp.257-261.", "Azami.A, Y., \"Climate passive architecture in hot and dry regions of iran, Passive and low energy cooling for the built environment\", Greece: Santorini, 2005, pp. 613-617.", "Fardpour, Tohid, \"Analysis of Iranian Traditional Architecture Through the Lens of Kenneth Frampton's \"Critical Regionalism\"\", American Journal of Engineering and Applied Sciences, 2013, 6 (2): 205-210.", "Ghobadian. Vahid, \"Climate Analysis of the Traditional Iranian Buildings\", 5th ed., Tehran: University of Tehran Press, 2008.\n[10]\tKasmai, Morteza, \"Climate & Architecture\", 4nd ed., 2006, pp. 107-130.\n[11]\tKiani, W. K., \"Cultural heritage organization of Iran\", Tehran, 1995.\n[12]\tPourvahidi, Parastoo, \"Bioclimatic Analysis of Vernacular Iranian Architecture\", Master diss., Eastern Mediterranean University, Gazimagusa, North Cyprus, 2010, 1-161.\n[13]\tPourvahidi, Parastoo, Mesut B. Ozdeniz, \"Bioclimatic analysis of Iranian climate for energy conservation in architecture\", Scientific Research and Essays, 2013, Vol. 8(1), pp. 6-16.\n[14]\tShojaei, S.A.R., Zahra khodayari, \"Sustainable Architecture In Arid Regions of Iran\", 5th Symposium on Advances in Science & Technology, May 12-17, 2011.\n[15]\tUtaberta, N., N. Sharifi, M. Surat, A. I. Che-Ani and N.M. Tawil, \"The Experience of Iranian Architecture in Direction of Urban Passages and Forming of Urban Structures to Increase Climatic Comfort\", World Academy of Science, Engineering and Technology, 2012, Vol. 67, pp. 637-641.\n[16]\tRetrieved on June 2, 2013 from website http://news.discovery.com/earth/global-warming/hottest-spot-on-earth-120416.htm\n[17]\tAttmann, Osman , \"Green architecture: overview\", Green architecture: advanced technologies and materials. definitions and operationalizations of green architecture, McGraw-Hill Professional, AccessEngineering, ICC (International Code Council), 2010, pp. 1-26.\n[18]\tRetrieved on May 28, 2013 from Website http://www.skyscrapercity.com/showthread.php?t=965506\n[19]\tPirnia, Mohammad Karim, Stylistic of Iranian Architecturem, 3rd ed., 1383, pp. 32.\n[20]\tRetrieved on April 18, 2013 from website Website: http://n-a-c.blogfa.com/cat-12.aspx\n[21]\tShokouhian.M, S., \"Enviromental effect of the courtyard in sustainable architecture of Iran\", Tehran: Islamic azad university, 2007.\n[22]\tRetrieved on April 26, 2013 from website http://www.gardenhistorysociety.org/post/agenda/the-gardens-of-persia/\n[23]\tLe Corbusier \"The Modulor: A Harmonious Measure to the Human Scale, Universally Applicable to Architecture and Mechanics\". Basel & Boston: Birkh\u00e4user, (2004) (First published in two volumes in 1954 and 1958.).\n[24]\tRetrieved on May 06, 2013 from website http://ghoolabad.com/index2.asp?id=26"]} Iran Central Plateau encompasses a large proportion of this country. The weather in these flat plains is warm and arid with very little precipitation. Different attempts in architecture have been done to alleviate the weather severity of this area and create a living place compatible with humans’ comfort criteria. Investigations have showed that some of the most successful approaches in traditional architecture of the area has been forgotten or are not being used widely. As sustainability is defined as an appropriate solution for environmental, economical, and social disorders, this research is a try to demonstrate the sustainability in aforementioned architecture and based on these studies, propounds solutions for today architecture in hot arid zones.