Tasneem Abbasi

Bio: Tasneem Abbasi is an academic researcher from Pondicherry University. The author has contributed to research in topics: Vermicompost & Biogas. The author has an hindex of 38, co-authored 142 publications receiving 5128 citations. Previous affiliations of Tasneem Abbasi include Masdar Institute of Science and Technology & University of Surrey.

Is the Use of Renewable Energy Sources an Answer to the Problems of Global Warming and Pollution

Abstract: It has always been a widely prevalent belief that renewable energy sources are clean and green in contrast to nonrenewable fossil fuels. The oil price shocks of 1973 and 1979, alongside increasing global awareness towards environmental pollution had stimulated great interest in the development of renewable energy sources during the early 1980s. But as the oil prices came down and few breakthroughs were achieved in that period for making the cost of renewable energy comparable or lesser to fossil fuel energy, the enthusiasm of the early 1980s began to wane. In more recent years the spectres of global warming and ocean acidification, which have been primarily attributed to fossil fuel burning, has caused a resurgence of interest in renewable energy sources. As illustrated in this article, scientists from all over the world are strongly advocating large-scale substitution of conventional energy sources with renewable alternatives on the premise that such a move would substantially reduce environmental degrad...

Production of clean energy by anaerobic digestion of phytomass—New prospects for a global warming amelioration technology

Abstract: Anaerobic digestion of animal dung generated combustible gas – this fact has been known since over 130 years and has been gainfully utilized in generating clean energy in the form of methane-rich ‘biogas’. During 1970s it was found that aquatic weeds and other phytomass, if anaerobically digested, also produced similarly combustible ‘bio’ gas. It raised great hopes that anaerobic digestion of phytomass will also enable generation of biogas that too on a much larger scale than is possible with animal manure. This, it was hoped, would also provide a means for utilizing weeds, crop wastes, and biodegradable municipal solid waste which otherwise cause environmental pollution. It appeared to be a ‘no lose’ possibility; it was hoped that soon the problems of weeds (and other biosolid wastes) as well as energy shortage, would vanish. At that time there was little realization of the global warming (GW) potential of methane nor of the fact that natural degradation of phytomass in the environment is causing massive quantities of GW gas emission. Hence, at that time, the potential benefits from anaerobic digestion of phytomass were perceived only in terms of pollution control and energy generation. But four decades have since elapsed and there is still no economically viable technology with which weeds and phytowastes can be gainfully converted to energy. This paper takes a look at what has happened and why. It also points towards the possibility of success finally emerging on the horizon. It would, hopefully, give a fresh impetus to the entire field of biomethanation R&D because all ‘methane capture’ technologies also indirectly contribute to very significant reduction in global warming.

The promise and the performance of the world's first two zero carbon eco-cities

Abstract: In recent years two major attempts have been made to develop ‘eco-city prototypes’ the Dongtan City in China and the Masdar City near Abu Dhabi. Both attempts have revolved round the premise that advanced post-modern technology, innovative urban planning, reliance on renewable energy, and emphasis on ‘total’ reuse can combine to achieve ‘zero carbon–zero waste’ existence. The plan of the two cities had also integrated strong business interests into the system, aiming to make ‘zero carbon–zero waste’ a kind of catch-phrase or a fashion statement that would enhance the value of the real estate the two eco-cities were planning to offer. The paper recapitulates the objectives that were set and assesses the present status of realization of those objectives. There is an already substantial and widening gap between the promise and the performance in both the cases; the review identifies the gaps and the possible reasons of their occurrence. It is highlighted that the expectation of a zero-waste existence is inherently flawed because the Second Law of Thermodynamics makes it impossible to attain. The paper brings out that no ‘eco-city’ concept can be translated into reality unless and until the inhabitants of the eco-city are prepared to voluntarily and consistently observe certain restrictions on resource consumption and to sacrifice some of the basically illusory but highly fancied ‘comforts’ which drive consumption in conventional habitations. It follows that many of those measures that are sought to be introduced in the eco-cities to make them cleaner and greener can very much be implemented in existing cities if only the same extent of voluntary participation from the lay public can be invoked that is expected in the ‘eco-cities’.

Accidental risk of superheated liquids and a framework for predicting the superheat limit

Abstract: The phenomenon of superheating of liquids has fostered the development of several beneficial technologies and has the potential of revolutionizing the design and application of thermal micro-machines. But liquid superheat is also behind some of the most common and destructive accidents in the process industry. These include boiling liquid expanding vapor explosion (BLEVE), which occurs when a vessel storing pressure liquefied gas such as propane, chlorine, or ammonia is accidentally depressurized. Superheating was also responsible for the catastrophic release of methyl isocyanate in Bhopal. Besides great losses of life and inanimate assets, such accidents often cause severe environmental contamination. In nuclear industry superheated liquids pose an ever-present threat of thermo-hydraulic explosion if a leak or a break occurs in a pipeline carrying a superheated coolant. In metallurgical industries accidental contact of molten metal with another substance of much lower boiling point—such as water—can superheat the latter, causing explosion of great severity and destructive potential. Accidental dropping of water in hot oil and the resulting explosive vaporization of superheated water has been identified as the cause the largest number of household kitchen accidents. Even as knowledge of superheat limit temperature (SLT)—which is the temperature above which a liquid cannot exist at a given pressure—is central to the safe design and control of several industrial operations, reliable experimental or theoretical methods do not exist with which SLT can be determined accurately or quickly. In this paper we describe an attempt to develop a framework with which SLT of new substances can be theoretically determined with fair degree of confidence. Seven cubic equation of state (EOS) have been transformed by the application of the Maxwell's and the SLT criteria to eliminate those parameters of which correct values cannot be determined with certainty. The transformed equations have then been solved to generate SLT values. A comparison between the calculated and the observed values has been done for 75 industrial chemicals. It reveals that for a large number of chemicals the transformed Redlich–Kwong (RK) EOS is able to predict the SLT within less then 1% deviation from its experimental value. In case of the SLT of noble gases the transformed van der Waals (vdW) EOS has the best predictive ability. Only in a very few cases other EOS give a closer fit than the RK-EOS and the vdW-EOS. The ‘second best fit’ is almost always achieved with either the RK-EOS or the Twu–Redlich–Kwong (TRK) EOS.

The role of hydrogen and fuel cells in the global energy system

Abstract: Hydrogen technologies have experienced cycles of excessive expectations followed by disillusion. Nonetheless, a growing body of evidence suggests these technologies form an attractive option for the deep decarbonisation of global energy systems, and that recent improvements in their cost and performance point towards economic viability as well. This paper is a comprehensive review of the potential role that hydrogen could play in the provision of electricity, heat, industry, transport and energy storage in a low-carbon energy system, and an assessment of the status of hydrogen in being able to fulfil that potential. The picture that emerges is one of qualified promise: hydrogen is well established in certain niches such as forklift trucks, while mainstream applications are now forthcoming. Hydrogen vehicles are available commercially in several countries, and 225 000 fuel cell home heating systems have been sold. This represents a step change from the situation of only five years ago. This review shows that challenges around cost and performance remain, and considerable improvements are still required for hydrogen to become truly competitive. But such competitiveness in the medium-term future no longer seems an unrealistic prospect, which fully justifies the growing interest and policy support for these technologies around the world.

Silver Nanoparticles: Synthesis, Characterization, Properties, Applications, and Therapeutic Approaches

Abstract: Recent advances in nanoscience and nanotechnology radically changed the way we diagnose, treat, and prevent various diseases in all aspects of human life. Silver nanoparticles (AgNPs) are one of the most vital and fascinating nanomaterials among several metallic nanoparticles that are involved in biomedical applications. AgNPs play an important role in nanoscience and nanotechnology, particularly in nanomedicine. Although several noble metals have been used for various purposes, AgNPs have been focused on potential applications in cancer diagnosis and therapy. In this review, we discuss the synthesis of AgNPs using physical, chemical, and biological methods. We also discuss the properties of AgNPs and methods for their characterization. More importantly, we extensively discuss the multifunctional bio-applications of AgNPs; for example, as antibacterial, antifungal, antiviral, anti-inflammatory, anti-angiogenic, and anti-cancer agents, and the mechanism of the anti-cancer activity of AgNPs. In addition, we discuss therapeutic approaches and challenges for cancer therapy using AgNPs. Finally, we conclude by discussing the future perspective of AgNPs.

A review of renewable energy sources, sustainability issues and climate change mitigation

Abstract: The world is fast becoming a global village due to the increasing daily requirement of energy by all population across the world while the earth in its form cannot change. The need for energy and its related services to satisfy human social and economic development, welfare and health is increasing. Returning to renewables to help mitigate climate change is an excellent approach which needs to be sustainable in order to meet energy demand of future generations. The study reviewed the opportunities associated with renewable energy sources which includes: Energy Security, Energy Access, Social and Economic development, Climate Change Mitigation, and reduction of environmental and health impacts. Despite these opportunities, there are challenges that hinder the sustainability of renewable energy sources towards climate change mitigation. These challenges include Market failures, lack of information, access to raw materials for future renewable resource deployment, and our daily carbon footprint. The ...

Hydrogen production from renewable and sustainable energy resources: Promising green energy carrier for clean development

Abstract: Fossil fuel consumption in transportation system and energy-intensive sectors as the principal pillar of civilization is associated with progressive release of greenhouse gases. Hydrogen as a promising energy carrier is a perfect candidate to supply the energy demand of the world and concomitantly reduce toxic emissions. This article gives an overview of the state-of-the-art hydrogen production technologies using renewable and sustainable energy resources. Hydrogen from supercritical water gasification (SCWG) of biomass is the most cost effective thermochemical process. Highly moisturized biomass is utilized directly in SCWG without any high cost drying process. In SCWG, hydrogen is produced at high pressure and small amount of energy is required to pressurize hydrogen in the storage tank. Tar and char formation decreases drastically in biomass SCWG. The low efficiency of solar to hydrogen system as well as expensive photovoltaic cell are the most important barriers for the widespread commercial development of solar-based hydrogen production. Since electricity costs play a crucial role on the final hydrogen price, to generate carbon free hydrogen from solar and wind energy at a competitive price with fossil fuels, the electrical energy cost should be four times less than commercial electricity prices.

A review on biomass as a fuel for boilers

Abstract: Currently, fossil fuels such as oil, coal and natural gas represent the prime energy sources in the world. However, it is anticipated that these sources of energy will deplete within the next 40–50 years. Moreover, the expected environmental damages such as the global warming, acid rain and urban smog due to the production of emissions from these sources have tempted the world to try to reduce carbon emissions by 80% and shift towards utilizing a variety of renewable energy resources (RES) which are less environmentally harmful such as solar, wind, biomass etc. in a sustainable way. Biomass is one of the earliest sources of energy with very specific properties. In this review, several aspects which are associated with burning biomass in boilers have been investigated such as composition of biomass, estimating the higher heating value of biomass, comparison between biomass and other fuels, combustion of biomass, co-firing of biomass and coal, impacts of biomass, economic and social analysis of biomass, transportation of biomass, densification of biomass, problems of biomass and future of biomass. It has been found that utilizing biomass in boilers offers many economical, social and environmental benefits such as financial net saving, conservation of fossil fuel resources, job opportunities creation and CO 2 and NO x emissions reduction. However, care should be taken to other environmental impacts of biomass such as land and water resources, soil erosion, loss of biodiversity and deforestation. Fouling, marketing, low heating value, storage and collections and handling are all associated problems when burning biomass in boilers. The future of biomass in boilers depends upon the development of the markets for fossil fuels and on policy decisions regarding the biomass market.