Posted by: PARTHA DAS SHARMA | September 22, 2010

ACID DRAINAGE FROM MINES AND ITS RELATED PROBLEMS

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Genuinely ‘Clean Coal’  – Solution for Reliable and Cheap Energy Source of Future

Partha Das Sharma, B.Tech(Hons.), E.mail: sharmapd1@gmail.com

Blog/Website: https://saferenvironment.wordpress.com, www.coalandfuel.blogspot.com

Introduction

Sufficient, reliable sources of energy are a necessity for industrialized nations. With global energy demand rising at an unprecedented rate, the world’s vast coal reserves are attracting growing interest. Despite its low cost and abundance, increasing concerns over greenhouse gases and other emissions from fossil fuels are altering the technological and regulatory environment for coal. Programs are underway to limit, reduce, and capture emissions from coal plants. This may result in the emergence of new generation technologies and the increased use of advanced emissions control technologies. In so doing, the costs and economics of coal use may change.

Types of Coal and Their Characteristics, in general:

Environmental Factors

Coal combustion produces emissions of air pollutants including sulfur dioxide (SO2), nitrogen oxides (NOx), particulate matter (PM), carbon dioxide (CO2), and mercury (Hg). SO2, NOx, and PM emissions are associated with air quality impacts and acidification of water resources, or acid rain. CO2 emissions contribute to global climate change. Mercury, which can move in multiple environmental pathways, is a neurological toxin in humans and wildlife.

A wide range of control technologies can be employed to reduce emissions of particulates, mercury, sulfur dioxide, and oxides of nitrogen.

Particulates are captured with baghouses (BH), electrostatic precipitators (ESP), and multiclones (MC). Nitrogen oxides (NOx) compliance actions may include a mix of combustion control technologies, such as low-NOx burners (LNB) and overfire air (OFA), and end-of-pipe emission control technologies, such as selective catalytic reduction (SCR) and selective non-catalytic reduction (SNCR).

Sulfur dioxide (SO2) compliance actions may include switching to lower-sulfur coal, retirements, and installation of various scrubber technologies, such as flue gas desulfurization (FGD), dry lime injection (DLI), and spray dry injector (SDI). Burning low-sulfur coal can reduce SO2 emissions from an uncontrolled plant by two-thirds; installing a scrubber can reduce emissions by 90 percent or more. Mercury can be reduced to a limited extent by conventional SO2 scrubbers; more advanced controls specifically designed to reduce mercury include carbon injection (CI) and baghouse (BH) equipment.

Carbon capture and sequestration (CCS) technologies are under evaluation for their potential for removing the CO2 emissions from coal-fired power plants. The commercially available method for capturing CO2 from a conventional pulverized coal-fired boiler is the use of an amine-based system to absorb CO2 from the flue gas stream, and its subsequent regeneration to produce a nearly pure product stream. An alternative method, known as oxy-combustion, to capture CO2 is to use oxygen rather than air as the oxidant in the combustion process that yields a flue gas stream comprised primarily of CO2 and H2O. By removing the water, a nearly pure CO2 stream can be produced.

Coal combustion produces significant quantities of solid waste by-products that can be put to beneficial use. Coal combustion waste products can be used as an ingredient in the manufacture of cement, asphalt, roofing shingles, gypsum, calcium chloride, lightweight aggregate, lightweight block, and low-strength backfill.

Emerging Coal Generation Technologies

Pulverized coal system (PC) is the conventional coal burning technology used in most of the cases. In this, finely ground coal is combusted to make steam that turns turbines and generates electricity. The raw coal is fed into the pulverizer along with air heated to approximately 650˚F from the boiler. As the coal is pulverized, the hot air dries it and blows the usable fine coal powder out to be used as fuel. The powdered coal is then blown directly to a burner in the boiler. The burner mixes the powdered coal in the air suspension with additional pre-heated combustion air and forces it out of a nozzle similar in action to fuel being atomized by an automotive fuel injector. Under normal operating conditions, there is enough heat in the combustion zone to ignite all the incoming fuel.

As environmental emission regulations have been tightened, many coal plants have employed a range of operational modifications and capital equipment investments. In addition to fuel switching, i.e., low-sulfur coal, technologies are available and emerging to reduce emissions from coal burning at three different stages: pre-combustion, combustion, and post-combustion. Pre-combustion cleaning involves the removal of impurities from coal with physical, chemical or biological processes. Advanced combustion processes include improvements in existing coal combustion processes and new processes that remove pollutants from coal as it is burned. Post-combustion cleaning involves the removal of pollutants from the downstream flue gas after combustion and before exiting the stack. Many of the post-combustion pollution control technologies have been widely commercialized and have evolved into proven, mature technologies.

In recent years, technological advancements have led to substantial reductions in the cost of controlling SO2 and NOx emissions. Some of the most successful advancements are low-NOx burners, Selective Catalytic Reduction (SCR), Selective Non-Catalytic Reduction (SNCR), and scrubbers. Advanced pollution controls installed on existing power plants or engineered into new facilities can provide effective and low cost ways to reduce sulfur dioxide and nitrogen emissions.

Advanced power generation technologies are complete electric power generating systems that offer superior efficiency and environmental performance over conventional coal-burning systems. These new processes, such as circulating fluidized bed (CFB) combustion, can improve both efficiency and emission control. Another category of advanced coal technologies involves the conversion of coal into another form of fuel, e.g., gas or liquid. In most of these cases, the new fuel form provides both energy and environmental benefits by reducing the pollutants emitted from combusting the new fuel as compared to coal. Integrated gasification combined cycle (IGCC) is an example of this type of technology.

a. Circulating Fluidized Bed (CFB) – CFB combustion evolved from efforts to control pollutant emissions without external emission controls, such as scrubbers. The CFB technology suspends solid fuels on upward-blowing jets of air during the combustion process, resulting in a turbulent mixing of gas and solids. The tumbling action, much like a bubbling fluid, provides more effective chemical reactions and heat transfer. The technology allows burning at temperatures well below the threshold where NOx form. In addition, the mixing action of CFB brings the flue gases into contact with a sulfur-absorbing chemical, such as limestone or dolomite, capturing more than 95 percent of the sulfur pollutants inside the boiler. The popularity of fluidized bed combustion is due not only to its capability of meeting SO2 and NOx emission standards without the need for expensive add-on controls but also technology’s fuel flexibility. Almost any combustible material, from coal to municipal waste, can be used for fuel.

b. Integrated Gasification Combined Cycle – Another emerging combustion technology, integrated gasification combined cycle (IGCC), converts coal to a gaseous form similar to natural gas before being burned. This advanced technology converts coal into a combustible synthetic gas by reaction with oxygen and heat/steam. Emissions from these plants are very low compared to other coal technologies because the gas is cleaned prior to combustion, burned in a gas turbine, and the resulting exhaust gases are used to produce steam that then drives a steam turbine. Typically 60 to 70 percent of the power comes from the gas turbine with IGCC. The result is an IGCC configuration that provides ultra-low pollution levels and, in addition, carbon-capture technologies can more readily be built on to the back end of IGCC plants than traditional pulverized coal combustion technologies.

On the front end of IGCC is a gasification technology. Worldwide, there are 117 operating plants that include 385 gasifiers. Products from the syn-gas produced from gasification include chemicals, liquid fuels, and electric power.

c. Super Critical Steam – The use of supercritical (SC) and ultra-supercritical (USC) steam, heated to a higher temperature than conventional boilers, has the potential to achieve greater generation efficiency, resulting in more output per unit of fuel as well as fewer pollutants. Efficiencies of 40 percent and higher have been demonstrated. SC and USC plants require the use of more durable metals and alloys in order to withstand the higher operating temperatures. Although several SC and USC coal plants have been constructed and operated in the United States, some have experienced operating difficulties due to the high tolerances required. In more recently constructed plants in Japan and elsewhere, anecdotal reports indicate that SC and USC plants have operated more reliably with fewer outages than earlier designs.

d. Oxy-combustion (Oxy-Coal) – Oxy-combustion, or oxy-coal involves the combustion of coal in a mixture of oxygen and re-circulated flue gas. The main benefits of oxy-combustion technology with CCS are:

* Reduction of carbon dioxide emissions up to nearly 96.9 percent removal

* Reduction of SO2

* Potential for enhancement of mercury removal in the baghouse and advanced SO2 controls

Because it uses conventional equipment already proven in the power generation industry, the oxy-combustion technology can readily be applied to new coal-fired power plants. Plant control during startup, shutdown, and load following is very similar to a conventional PC plant. Finally, the key process principles have been proven in the past including air separation and flue gas recycle (FGR).

However, several challenges to oxy-combustion have also been identified:

* Air infiltration into the boiler dilutes the resulting flue gases. This could potentially be minimized by improved boiler materials, sealants, control technologies, and membranes.

* Combustion of fuels in a purified oxygen stream would occur at temperatures too high for existing boiler or turbine materials. This issue is being addressed by diluting the oxygen via the FGR, which results in an increase of the auxiliary power load and decreases efficiency. Further developments aim at increasing the efficiency of the FGR and improved boiler materials.

* The current capital and operating costs of specialized components are high.

* Plant efficiency is reduced by the use of the auxiliary load of FGR and air separation equipment.

Conclusion

With introduction of improved and emerging technology, the efficiency and cleanliness of coal-fired power stations is improving. Genuinely clean coal – i.e.: one that emits close to zero CO2 thanks to carbon capture and storage technology – is not expected to become economically viable before twenty years, are now viable. Thus, coal is making a comeback as a cheap and reliable source of energy.

References:

* http://www.world-nuclear.org/info/inf83.html

* Clean coal technology (CCT) – To mitigate global warming and climate change for cleaner and safer environment: https://saferenvironment.wordpress.com/2008/11/17/clean-coal-technology-cct-%E2%80%93-to-mitigate-global-warming-and-climate-change-for-cleaner-and-safer-environment/

***

Posted by: PARTHA DAS SHARMA | May 1, 2010

Coastal Erosion And Its Control

Posted by: PARTHA DAS SHARMA | April 9, 2010

Acid Mine Drainage (AMD) and its control

Posted by: PARTHA DAS SHARMA | April 1, 2010

THE ENVIRONMENT PROTECTION ACT, 1986 (IN INDIA)

INTRODUCTION…..

In 1980, the Deptt. of Environment was established in India. Later on it became the Ministry of Environment and Forests in 1985. EPA,1986 came into force soon after the Bhopal Gas Tragedy.

OBJECTIVE……

Objective is, to provide the protection and improvement of environment. In EPA, article 48A, specify that the State shall protect and improve the environment.

Also, to safeguard the forests and wildlife of the country. Acc. to sec 51(A) every citizen shall protect the environment. EPA is applicable to whole India, including J&K.

IMPORTANT TERMINOLOGY….

“Environment” It includes water, air, and land and the interrelationship which exists among and between water, air and land and human beings, other living creatures, plants, microorganism and property. “Environmental Pollutant” means any solid, liquid or gaseous substance present in such concentration as may be, or tend to be injurious to environment.

“Environmental pollutant” means any solid, liquid or gaseous substances present in such concentration as may be or tend to be injurious to environment and human being. “Hazardous Substance” means any substance or preparation which, by reasons of its chemical or physico-chemical properties, is liable to cause harm to human beings or other living creatures. “Handling” In relation to any substance, it means the manufacturing, processing, treatment, packaging, storage, transportation, use, collection, destruction, conversion, offering for sale, etc

“Environmental pollution” means imbalance in environment. The materials or substances when after mixing in air, water or land alters their properties in such manner, that the very use of all or any of the air water and land by man and any other living organism becomes lethal and dangerous for health. “Occupier” It means a person who has control over the affairs of the factory or the premises, and includes, in relation to any substance, the person in possession of the substance.

“Hazardous substance” means any substance or preparation which, by reason of its chemical or physico-chemical properties or handling, is liable to cause harm to human beings, other living creatures, plant, micro-organism, property or the environment.

POWERS PROVIDED BY THE ACT TO CENTRAL GOVTT.….

To make rules to regulate environmental pollution; To notify standards and maximum limits of pollutants of air, water, and soil for various areas and purposes; Prohibition and restriction on the handling of hazardous substances, and location of industries (Sections 3-6).

Under Sec (3): may constitute authority or authorities for the purpose of exercising of performing such of the powers and functions; Under Sec (4): may appoint a person for inspection; Under Sec (5): may issue directions in writing to any officers or any authority to comply; Under Sec (6): it empower the government to make rules to achieve the object of the Act.

Under Sec (7): persons carrying on industry, operation etc. not to allow emission or discharge of environmental pollutants in excess of the standards; Under Sec (8): persons handling hazardous substances must comply with procedural safeguards.

PENALITY….

Whoever Person found to be the cause of pollution, may be liable for punishment for a term which may extend to five years or with fine which may extend to one lakh rupees or both (Sec 15, 16, 17). If not comply fine of Rs. 5000 per day extra, still if not comply for more than one year, then imprisonment may extend up to 7 years.

Section 17 specifies that Head of the department/ incharge of small unit may be liable for punishment if the owner /occupier produce enough evidence of innocence. The state govtt. have power to close or cancel or deny the authorization to run the factory/institution/hospital whichever is causing pollution.

ENVIRONMENTAL LAWS….

Following is a list of the environmental legislations that have come into effect: General, Forest and wildlife, Water, Air etc.

General….

1986 – The Environment (Protection) Act; 1986 – The Environment (Protection) Rules; 1989 – The objective of Hazardous Waste (Management and Handling) Rules; 1989 – The Manufacture, Storage, and Import of Hazardous Rules; 1989 – The Manufacture, Use, Import, Export, and Storage of hazardous Micro-organisms/ Genetically Engineered Organisms or Cells Rules; 1991 – The Public Liability Insurance Act and Rules and Amendment, 1992

FOREST AND WILDLIFE….

1927 – The Indian Forest Act and Amendment, 1984; 1972 – The Wildlife Protection Act, Rules 1973 and Amendment 1991; 1980 – The Forest (Conservation) Act and Rules, 1981.

WATER….

1882 – The Easement Act ; 1897 – The Indian Fisheries Act ; 1956 – The River Boards Act ; 1970 – The Merchant Shipping Act ; 1974 – The Water (Prevention and Control of Pollution) Act ; 1991 – The Coastal Regulation Zone Notification.

AIR….

1948 – The Factories Act and Amendment in 1987 ; 1981 – The Air (Prevention and Control of Pollution) Act ; 1982 – The Air (Prevention and Control of Pollution) Rules ; 1982 – The Atomic Energy Act ; 1987 – The Air (Prevention and Control of Pollution) Amendment Act ; 1988 – The Motor Vehicles Act.

Posted by: PARTHA DAS SHARMA | March 6, 2010

Rain-water harvesting and artificial recharge of ground water

Posted by: PARTHA DAS SHARMA | March 4, 2010

Environmental Mining Accidents – Disasters to be checked

Environmental Mining Accidents – Disasters to be checked

1. Introduction – Environmental disaster is a disaster that is due to human activities and some of the most publicized environmental disasters are associated with the mining industry. These disasters are attributed to both natural and mining-related causes. Acid drainage, for example, formed by rainwater or snowmelt in contact with mineral deposits can damage nearby ecosystems by polluting streams and destroying wildlife. The mining and processing of ores, however, may accentuate and accelerate the natural processes.

On a long-term basis, mining can increase the acidity of water in streams; cause increased sediment loads, some of which may be metal-laden, in drainage basins; initiate dust with windborne pathogens; and cause the release of toxic chemicals, some contained in exposed ore bodies and waste rock piles and some derived from ore-processing reactions. Contaminants containing such toxic chemicals as cyanide and lead may be transported far from a mining site by water or wind, polluting soils, groundwater, rivers, and the atmosphere. These toxic chemicals can be remobilized intermittently (e.g., by intense wind or rainstorms) and eventually distributed over vast regions. Some of this contamination, because of its scale or intensity, may not be amenable to remediation.

Mining may also have effects that can be short-term, depending on their severity, such as distortion to the surrounding topography or removal of vegetation. In many cases, these effects may be minimized or even prevented by means of a comprehensive mining plan that includes a reclamation and remediation stage.

2. Environmental Impacts by use of Toxic Chemicals in Mining or Ore Processing with Case Studies –

Leaching and Floatation Process:

Copper: Sulfuric Acid is used for leaching of copper from oxide ore, and some sulfide ores. The leaching solution is claimed to be diluted and recycled. However, it is recycled into lined ponds of high toxic levels of sulfuric acid. The sulfuric acid can enter the soil and groundwater through breaks, spills, tears in liners.

Gold: Cyanide is used for leaching gold. This leaching has been banned in many of the developed countries.

Toxic chemicals are used in the Flotation Process to separate the copper and molybdenum out of the milled powder. This Flotation process is the major extraction method. Some chemicals produce bubbles that that the copper adheres to and the “bad stuff” falls to the bottom. These chemicals are hydrocarbons with complex configurations, but some are as simple as kerosene. It is claimed that the volatile organics used in the Flotation Process do not go into the slurry that goes into the tailings impoundment because they are filtered out before the slurry goes to the impoundment. This is not a sound analysis.

a) Filtration is not a treatment technology for volatile organics. Treatment is pushing air the solution which releases the volatile chemicals into the air.

b) Some are amine compounds that break down into nitrates, so the presence of nitrates in the groundwater is an indicator of travel of these compounds, which can be very mobile in an oxygen solution.

Super powerful explosives—ANFO (ammonium nitrate and fuel oil)—used to blast the rock in the pit leaves traces of nitrates in the blasted rock and the flotation solution.

Case Studies:

* The Summitville Mine in Colorado has become a case study of environmental damage as a result of mining. Gold was mined there from 1870 until 1992. In 1994 the U.S. Environmental Protection Agency (EPA) declared the area a Superfund site. Some of the following events affected the environment at the mine: Geologic characteristics at the mine site contributed to the generation of both natural and mining-related acid drainage; the height of the containing dike for cyanide leach solutions (used to chemically extract gold) was below the level required for snowstorms and spring runoff; broken pump lines and a French drain beneath the leach pad caused cyanide-contaminated solutions to be released into the local watershed ; several waste rock piles at the mine reacted with rain and snowmelt to form acidic waters that flowed into area streams; an underground tunnel released large volumes of contaminated waters; and mining deforested much of the land. Remediation of the site has included such projects as backfilling mine waste into existing open pits, which reduces polluted water percolating into the ground; plugging underground tunnels; and replanting. Remediation is ongoing with the goal of restoring the nearby Alamosa River to support aquatic life; the U.S. Public Health Service classified this site as “no apparent public health hazard.”

* Another case study is the Iron Mountain Mine in California, which the EPA declared a Superfund site in 1983. Mining for copper, gold, silver, and zinc began in 1879 and continued until 1963 using underground and open-pit methods. The site contains inactive mines and numerous waste piles from which harmful quantities of untreated acidic, metal-rich waters were discharged. Mining operations fractured the mountain, changing the hydrology and exposing the mineral deposit to oxygen and water, which resulted in intense acid mine drainage into nearby creeks and waterways. These caused numerous fish kills and posed a health risk to the area drinking water. Some current remediation projects include: capping areas of the mine and the diversion of nearby creeks, both of which serve to reduce surface water contamination; construction of a retention reservoir to control the area source acid mine drainage discharges; enlargement of a landfill to provide an additional thirty years of storage capacity for heavy metals sludges; and construction of a significant upgrade to facilities in mine tunnels to assure safe travel for workers and equipment to perform maintenance and routinely remove mine wastes from the tunnels and other projects.

* Leaching Gold has been banned in Montana, thanks to the heroic efforts of Montana Environmental Information Center who led a twice-won, citizen- initiated law banning cyanide heap-leach mining in Montana. The law has been upheld in the district, federal, and state Supreme Courts despite Canyon Resources (Mining), Inc.’s efforts to repeal it in order to develop a massive open-pit, cyanide leach gold mine less than 800 feet from the Blackfoot River headwaters.

Initiative 137 was a response to the abysmal track record of open pit cyanide leach mining in Montana, as exemplified by cleanup fiascos  at the Golden Sunlight, Zortman/Landusky, and Kendall mines and the Montana Department of Environmental Quality’s failure to adequately regulate such mines as required by state law.

More case studies at following links:

http://www.miningwatch.ca/en/one-worlds-worst-mine-disasters-gets-worse-bhp-admits-massive-environmental-damage-ok-tedi-mine-papu

http://www.abc.net.au/news/stories/2008/09/06/2357374.htm

http://www.minesandcommunities.org/article.php?a=8918

http://en.wikipedia.org/wiki/Ok_Tedi_environmental_disaster

http://www.wsws.org/articles/2002/apr2002/png-a09.shtml

3. Use of bacteria in industry: Applied bacteriology – Bacteria have many properties that are useful to industry. The diversity of the Bacterial kingdom is reflected by the diverse applications of bacteria as a cheap labor force.

* Bacteria can be used to mine gold! well, not quite, but the discovery that Thiobacillus ferrooxidans can concentrate gold trapped in rock minerals drew the attention of mining companies, and they are now developing a method of applying these bacteria in the gold mining industry. Biomining may be the way of mining in the future, and researchers are now trying to modify the bacteria so that they collect the ores of interest.

* Certain bacteria are used to clean our waste: be it pollution, compost heaps, or sewage: bacteria can get rid of things. The subject may not appeal to you, but there are microbes that clean sewage. That industrial waste can be cleaned with bacteria has been known for over 30 years. Bacteria have a taste for mining wastewaters no matter how toxic the contaminants are for animals and humans. Specialized bacteria metabolize these toxic chemicals into non-toxic, or less toxic compounds. Drunk bacteria can clean up mining pollutants.

* Bacteria can degrade herbicides.Also pesticides can be degraded by bacteria and thus can groundwater that is contaminated be cleaned.

* How can ammonia, a component of dung and fertilizer, be benificial to plants? Only when nitrifying bacteria convert it to nitrite, and others change that to nitrate, which is a component that plants can use directly.

* Bacteria eat oil and a whole range of organic chemicals, like gasoline, diesel, benzene, toluene, acetone, and even PCB’s. Most of these are toxic to humans and higher organisms, can they be degraded into safe compounds by bacteria. This application of bacteria is called bioremediation. More about biomediation: using bacteria to clean up hazardous waste.

* The most spectacular bacterial species in use for cleaning up our industrial waste is D. radiodurans, which is the only bacteria so far known that can survive high doses of radioactivity. It can be used to clean up radioactive waste. The radioactivity cannot be destroyed by the bacteria, but they can ‘eat’ all chemical toxic solvents in which these radioactive wastes are often present, and thus slow down or prevent corrosion.

* Did you know? Bacteria can make plastic! And yet other bacteria can eat plastic.

Assessment of Sustainable Development : ‘Bellagio Principles’ for Assessment

Author: Partha Das Sharma, E.mail: sharmapd1@gmail.com,

Website: https://saferenvironment.wordpress.com

A. Introduction and Basic notion of Sustainability – In general terms, the idea of sustainability is the persistence of certain necessary and desired characteristics of people, their communities and organizations, and the surrounding ecosystem over a very long period of time (indefinitely). Achieving progress toward sustainability thus implies maintaining and preferably improving, both human and ecosystem wellbeing, not one at the expense of the other. The idea expresses the interdependence between people and the surrounding world.

Development means to expand or realize the potentialities of, bring gradually to a fuller, greater, or better state. It has both qualitative and quantitative characteristics and is to be differentiated from growth which applies to a quantitative increase in physical dimensions. In fact, sustainable development is not a “fixed state of harmony”. Rather, it is an ongoing process of evolution in which people take actions leading to development that meets their current needs without compromising the ability of future generations to meet their own needs. Conversely, actions that reduce the ability of future generations to meet their own needs should be avoided.

The ideas presented are not complicated. They say that certain features of the world need preserving and improvement if life (for people, plants, and animals) is to endure. Further, they reinforce the concept of sustainable development as value-based. Thus the design of a sustainable world — the choice and degree to which “certain features” are to be sustained — will depend on the operating set of values, values which will shift over time and will vary within communities and from place to place.

Achieving progress toward sustainable development is clearly a matter of social choice, choice on the part of individuals and families, of communities, of the many organizations of civil society, and of government. Because it involves choice, change is only possible with the broad involvement of the general public and decision-makers in government and across civil society. And because of the need for this involvement, care must continually be taken to ensure that substantive conceptual and technical issues are considered within the context of the delicate value-driven processes of real, day-to-day decision-making. In this way, new insights can effectively be fed to decision-makers and conversely, the processes of assessment and decision-making can enhance technical and public inquiry. The process is a two-way street.

B. Approaches to Assessing Progress toward Sustainable Development – A number of approaches to assessing progress toward sustainable development are currently being developed and tested. In most cases, the emphasis is on choosing appropriate measures for the task and in organizing them in a meaningful way. A dominant concern is to effectively communicate the result to the general public, as well as to decision-makers in civil society and in government.

An effective framework accomplishes two important goals: first, it helps determine priorities in the choice of indicators; and second, it triggers the identification of indicators which may be more important in the future. Any framework that is chosen reflects some sort of conceptual model against which the real world can be set. Five groups of models appear to be emerging as influential in assessing progress toward sustainable development. These include: (1) models with roots in economics; (2) stress and stress-response models; (3) multiple capital models; (4) various forms of the three-part or theme “social, economic, environment” model; and (5) the linked human-ecosystem well-being model.

C. The Need for Guidelines: The Rationale Underlying the Bellagio Principles for Assessment – The debate regarding what might be a broadly accepted way of measuring, monitoring, and assessing progress to sustainable development has deep roots. Some suggest that the issue is none other than the age old question “What is the good life?” evoked by the ancient Greeks.

There is a clear link to “results-based management” and associated reporting, whether the scale be a local project, a corporate enterprise, or a large political jurisdiction. Faced with growing demands that expenditures of increasingly limited resources be both well directed and monitored in terms of success, decision-makers are actively pursuing systems for ensuring accountability. Although many have offered lists of indicators that would supplement the GDP in an overall assessment of progress, consensus has not emerged. Many question whether or not a common list is even possible, given the wide variety of natural conditions and the differences in values apparent from place-to-place.

D. The Bellagio Principles for Assessment

a. Background – In 1987, the World Commission on Environment and Development  called for the development of new ways to measure and assess progress toward sustainable development. This call has been subsequently echoed in Agenda 21 of the 1992 Earth Summit and through activities that range from local to global in scale. In response, significant efforts to assess performance have been made by corporations, non-government organizations, academics, communities, nations, and international organizations.

In November 1996, an international group of measurement practitioners and researchers from five continents came together at the Rockefeller Foundation’s Study and Conference Center in Bellagio, Italy to review progress to date and to synthesize insights from practical ongoing efforts. The assessment principles resulted and were unanimously endorsed.

b. Their Uses and Beneficiaries or UsersThese principles serve as guidelines for the whole of the assessment process including the choice and design of indicators, their interpretation and communication of the result. They are interrelated and should be applied as a complete set. They are intended for use in starting and improving assessment activities of community groups, non-government organizations, corporations, national governments, and international institutions.

c. OverviewThese principles deal with four aspects of assessing progress toward sustainable development. Principle 1 deals with the starting point of any assessment – establishing a vision of sustainable development and clear goals that provide a practical definition of that vision in terms that are meaningful for the decision-making unit in question. Principles 2 through 5 deal with the content of any assessment and the need to merge a sense of the overall system with a practical focus on current priority issues. Principles 6 through 8 deal with key issues of the process of assessment, while Principles 9 and 10 deal with the necessity for establishing a continuing capacity for assessment.

1. GUIDING VISION AND GOALS – Assessment of progress toward sustainable development should:

• be guided by a clear vision of sustainable development and goals that define that vision

2. HOLISTIC PERSPECTIVE – Assessment of progress toward sustainable development should:

• include review of the whole system as well as its parts

• consider the well-being of social, ecological, and economic sub-systems, their state as well as the direction and rate of change of that state, of their component parts, and the interaction between parts

• consider both positive and negative consequences of human activity, in a way that reflects the costs and benefits for human and ecological systems, in monetary and non-monetary terms

3. ESSENTIAL ELEMENTS – Assessment of progress toward sustainable development should:

• consider equity and disparity within the current population and between present and future generations, dealing with such concerns as resource use, over-consumption and poverty, human rights, and access to services, as appropriate

• consider the ecological conditions on which life depends

• consider economic development and other, non-market activities that contribute to human/social well-being

4. ADEQUATE SCOPE – Assessment of progress toward sustainable development should:

• adopt a time horizon long enough to capture both human and ecosystem time scales thus responding to needs of future generations as well as those current to short term decision-making

• define the space of study large enough to include not only local but also long distance impacts on people and ecosystems

• build on historic and current conditions to anticipate future conditions – where we want to go, where we could go

5. PRACTICAL FOCUS – Assessment of progress toward sustainable development should be based on:

• an explicit set of categories or an organizing framework that links vision and goals to indicators and assessment criteria

• a limited number of key issues for analysis

• a limited number of indicators or indicator combinations to provide a clearer signal of progress

• standardizing measurement wherever possible to permit comparison

• comparing indicator values to targets, reference values, ranges, thresholds, or direction of trends, as appropriate

6. OPENNESS – Assessment of progress toward sustainable development should:

• make the methods and data that are used accessible to all

• make explicit all judgments, assumptions, and uncertainties in data and interpretations

7. EFFECTIVE COMMUNICATION – Assessment of progress toward sustainable development should:

• be designed to address the needs of the audience and set of users

• draw from indicators and other tools that are stimulating and serve to engage decision-makers

• aim, from the outset, for simplicity in structure and use of clear and plain language

8. BROAD PARTICIPATION – Assessment of progress toward sustainable development should:

• obtain broad representation of key grass-roots, professional, technical and social groups, including youth, women, and indigenous people – to ensure recognition of diverse and changing values

• ensure the participation of decision-makers to secure a firm link to adopted policies and resulting action

9. ONGOING ASSESSMENT – Assessment of progress toward sustainable development should:

• develop a capacity for repeated measurement to determine trends

• be iterative, adaptive, and responsive to change and uncertainty because systems are complex and change frequently

• adjust goals, frameworks, and indicators as new insights are gained

• promote development of collective learning and feedback to decision- making

10. INSTITUTIONAL CAPACITY – Continuity of assessing progress toward sustainable development should be assured by:

• clearly assigning responsibility and providing ongoing support in the decision-making process

• providing institutional capacity for data collection, maintenance, and documentation

• supporting development of local assessment capacity

Thus, the Bellagio Principles for Assessment are guidelines for undertaking and improving assessments of progress toward sustainable development. These principles are helpful in selecting indicators, measuring progress, interpreting and communicating assessment results. They are intended for use in determining starting points, specifying content, and suggesting scope. As a set they help build the capacity for doing assessments.

E. Summary and conclusion – In summary, sustainable development commits us to considering the long-term and to recognizing our place within the ecosystem. It encourages a continuing reflection on the implications of human activity. It provides a new perspective from which to see the world. It is a perspective that forces the bridging of many ideas and disciplines (contemporary and traditional) that have previously remained disparate. Those using this perspective, including the Brundtland Commission and participants at the Earth Summit among many others, have come to the conclusion that the current nature of human activity is inadequate for meeting current needs and is seriously undermining opportunities for future generations.

The Bellagio Principles for Assessment serve to focus the perspective described above. They are offered in the belief that seeing differently is the first step to doing differently.

References:

* BellagioSTAMP SusTainability Assessment and Measurement Principles

http://www.iisd.org/measure/principles/progress/bellagiostamp/

* Tools and methods for integrated analysis and assessment of sustainable development: http://www.eoearth.org/article/Tools_and_methods_for_integrated_analysis_and_assessment_of_sustainable_development

* Environmental Impact Assessment and Sustainable Development: http://www.allacademic.com/meta/p_mla_apa_research_citation/0/9/6/3/5/p96350_index.html

* Part 2. Sustainable development assessment framework: http://www.liebertonline.com/doi/abs/10.1089/ind.2007.3.160

Posted by: PARTHA DAS SHARMA | February 6, 2010

Pollution Control in Recycling Industry is most essential

Pollution Control in Recycling Industry:

1. Introduction – Recycling industry frequently causes pollution to the environment. It is either the same or more than any other industrial activities. For example, paper recycling causes water pollution, which affect agricultural and fishery production. Refineries of metal scrap industry cause air and water pollution. Lead acid batteries recycling is a typical industry causing environmental pollution in developing countries.

When hazardous heavy metals are discharged to the environment, causes health damages. In fact, many small scale recycling industries without any pollution control mechanism exist in developing countries. Large production capacity recycling plants can afford to invest in pollution control equipment and hire technological experts to control pollution. It is easy for government to enforce pollution control regulation on big companies, which have financial and technological capacity to deal with the problem. It has been observed both in developed and developing countries that if the government strengthens the enforcement in small scale industries, it is possible that small scale industry migrate to remote areas, and carry out same business behind the wall.

It has also been observed that informal recyclers dominate the market of collected recyclable waste, because their cost of recycling is cheaper than that of formal recyclers. The competitiveness of informal recycler comes from non payment of taxes and no investment in pollution control. As a result, formal recycler with pollution control equipment and systems faces lack of recyclable waste, which becomes obstacle for the growth of formal recycler. This situation makes recycling industry as one of the most polluting industries in developing countries.

2. Pollution from Small and Medium Recycling Industries – The scrap recycling industry is growing at an exponential pace, specially in developing countries. The major source of raw material for this industry is recyclable scrap generated from municipal solid waste and domestic industry. The majority of recycling industry operates in medium to small scale unorganized sector without any pollution control. This results in uncontrolled emissions leading to environmental pollution. Therefore, it is pertinent to assess the structure of small to medium scale recycling industry, their recycling technologies used, and their pollution potential. At sector level, the recycling industry is generally, organized into paper, plastic, ferrous and non-ferrous sectors. In the non-ferrous sector, the majority of recycling industry is involved in zinc, copper and lead production. E-waste is a new waste stream, which provides raw material to the ferrous and non-ferrous recycling sector.

3. Processes and Technologies for Recycling and their pollution potential – Processes and technologies used in recycling sector ranges from advanced to very crude in nature.

a. Waste paper pulp is produced from two types of plants. The low quality of paper is produced by mechanically pulping the waste paper without chemical use. This pulp is used to produce brown paper and paper board. The good quality paper is produced by mechanical pulping followed by removal of inks/ pigments and bleaching. Most de- inking is done by ‘washing’ or floatation, or a combination of both the techniques. Washing is used to remove small particles of ink while flotation is used to remove ink particles which are too small to be removed by screens and cleaners but too big to be removed by washing. Both the processes involve the use of chemicals. The washing technique uses chemicals known as wetting agents and surfactants to detach ink particles from wastepaper. The particles are then removed through repeated washing. The floatation process is based on ink agglomeration chemistry. After the ink is detached from the wastepaper, the ink particles are made to stick together by using suitable collectors like fatty acid soap. The resulting slurry is then taken to a flotation cell where lime is added to make them hydrophobic (so that they do not dissolve in water). The ink particles then get attached to air bubbles passed through the slurry and are finally discharged as foam sludge. This process can handle both old newspapers as well as coated paper, which is used to print magazines. Starch and calcium carbonate are added to strengthen the pulp followed by blending with water to achieve proper pulp to water ratio. Alum, rosin, talc and acid are added to condition the paper before it is sent to paper machine, where steam is used for drying.

The major pollutants emitted from waste paper pulping are effluents and solid waste. Effluents are generated during pulping especially during de-inking, blending, conditioning and drying. Processing wastepaper generates sludge. In case the wastepaper is de-inked, the sludge contains heavy metals. Industrialized countries usually incinerate de-inking sludge. But in most of developing countries, most of it is disposed of in landfill or sold out.

b. Both consumer and industrial plastic waste generated is recycled. After sorting and cleaning, the plastic waste is grinded, cleaned and dried. After drying, it is agglomerated and further grinded. After grinding it is granulated and packaged.

Plastic recycling process generates fugitive dust, waste water on account of cleaning and solid waste. Since no chemical process/ burning is involved in plastic grinding and granulation, effluents have high suspended solids.

c. Small scale steel producers mostly use scrap-sponge iron-pig iron combination to produce steel ingots (for long products) using Electric Arc Furnace (EAF) or Induction Arc Furnace (IAF) route.

Though the units in steel sector are in small scale sector but quantity of pollutants generated by them is significant. The number of units in different clusters produces huge quantity of obnoxious fumes and discharge effluents without any pollution control devices, causing severe pollution in surrounding areas.

d. The majority of the secondary zinc units use both mechanical and electrolytic method while some units recover zinc from zinc ash by mechanical methods and sell fines (mainly 50-60percent zinc oxide) to zinc chemical manufacturers. Mostly, the raw material used for secondary zinc production by zinc recyclers is zinc ash/ skimming/ dross and steam blowing, which arises as a waste from domestic and imported galvanizing industry. Two types of dross namely top dross that floats on the top of the bath and the bottom dross that sinks to the bottom of the galvanizing bath based on the specific gravity of the material are obtained as raw material from the galvanizing industry. Zinc content in dross’s lies in the range 90–96%. The technology followed to extract zinc is hydrometallurgical based involving leaching, metal purification, separation, precipitation and electrolysis. In some of the units, ZnO is manufactured from the secondary zinc following pyro-metallurgical processes, which involves carbon reduction and vaporization of zinc followed by controlled oxidation to produce ZnO. The process of zinc extraction from zinc ash consists of material preparation, leaching, purification, electrolysis/melting and bleeds off. Zinc ash is generally available in the form of lumps and chips. It is therefore, first crushed and then pulverized to separate out metallic zinc from fine ash. On melting and casting, metallic zinc is obtained. Fine ash is subjected to calcinations in oil fired rotary kiln at 9000C. Calcined ash lumps are pulverized again to get particle size of 100 mesh. The calcined fine ash is then treated with sulphuric acid and/or spent electrolyte generated during electrolysis for leaching operation. During this operation, compressed air and pyrolusite (MnO2) are added to oxidize ferrous ions to ferric ions. Leaching of zinc is continued till pH 4.5 to 5 where oxidized impurity of iron is hydrolyzed to ferric hydroxide precipitate. The clear solution of zinc sulphate is then sent for purification. In the first stage, copper is cemented out with addition of zinc dust/powder. The resultant pulp is filtered to remove copper as copper cement and filtrate to taken to second stage purification. In the second stage, solution is treated with Di-methyl Glycol (DMG) to remove impurity of nickel. In the third stage purification, activated charcoal is added to remove organic impurities. The purified solution mixed with spent electrolyte is electrolyzed using lead anodes and aluminum cathodes. Zinc metal deposits on cathode and oxygen is given off at anode and sulphuric acid is regenerated in the process. Deposited zinc is stripped off manually after every 24 hours and is melted in oil fired crucible furnace. Molten zinc metal is cast as zinc ingots. Spent acid is reused in the process. Bleed off, to lower down the impurities in the system some zinc sulphate is bled off time to time. This is used to manufacture zinc sulphate crystals.

Air and water pollution and solid waste management are the major issues in secondary zinc recovery units. Pollutant emissions take place from rotary kiln. Effluent discharge occurs during leaching, electrolysis and bleeds off. Waste is mostly in the form of residues, which are often disposed off in unsystematic landfills, though some industries follow the safe handling and disposal procedure laid down officially by monitoring agencies.

e. Copper recycling sector uses copper based industrial waste suitable for copper recovery through pyro-metallurgical and hydro-metallurgical processes. The choice of the process can be made on the basis of physical form, copper content, chemical nature, chemical composition and possible recovery process. These wastes include converter slag, anode slag, ETP (effluent treatment plants) sludge, anode slime etc. Wastes like dross, reverts etc. are best recycled by pyro-metallurgical process including melting, fire refining and electro-refining. The converter slag is also recycled using smelting furnace and precious metals like Ag and Au are recovered from the anode slime by using electrolysis. Other waste except for high grade mill scale can be recycled by hydrometallurgical processing, e.g., slag is subjected to copper recovery by flotation and the residual slag can be smelted in an electric arc furnace.

Most of the secondary copper units do not follow the proper processing technologies and discharge effluents in the surrounding environment, causing air, water and soil contamination. Pollutant emissions, which take place from the secondary copper recovery processes, are particulate matter, fugitive emissions, volatile organic compounds, hydrogen chloride gas, dioxins and chlorinated furans. Acidic effluents are discharged during electrolysis and bleed off. Solid wastes from secondary copper units in the form of residues, metal oxides, un-burnt insulation, products of incomplete combustion are often disposed off in unsystematic landfills, though some industries follow the safe handling and disposal procedure laid down officially by monitoring agencies.

f. Recycling of Lead Acid Battery is one of the most hazardous jobs. Since it became difficult to process lead in the plant due to public opposition, some informal operators used drums in stead of smelting furnace to heat batteries by propane to melt electrolyte lead to recover lead without any pollution control. They conducted such operations underground, in a most clandestine manner. Secondary lead refining process is a batch process based on traditional pyro- metallurgical methods. Batch refining is carried out in hemispherical vessel usually stirred to mix the reactants. The metal is held molten while reaction products float out and recovered from the surface. These systems typically have no pollution control system. However, lead of purity of 99.99percent is recovered in these units.

Some of the pollution related issues include air and water pollution and solid waste management. During the processing of spent lead-acid battery in backyard units, operations like breaking, crushing, screening, dry mixing etc. generate airborne lead dust which directly or indirectly enter into the human system and the surroundings of the working area. Effluent discharge occurs during battery treatment. Since lead is a very toxic material, disposal of the solid wastes from secondary lead production in the secured landfill is essential and mandatory.

g. Most of the waste/used oil re-refining units in the small scale sector use the acid-clay process. This process has the disadvantage of resulting in the generation of large quantities of hazardous and toxic acid sludge and clay contaminated with oil and heavy metals.

Since the informal waste/ used oil recycling occurs in small scale sector, they are a major source of environmental pollution. A large number of roadside garages drain used oils from automobile engines without any record of the next destination of such oils. Used motor oil is also burned, generally in inadequate equipped installations. Such operations produce large quantities of heavy metal emission particles, toxic gases (SO2, NOx, HCl) and residue products, which are ranked among the most toxic in comparison with other environmental particles.

h. There are more than twenty three processes, which generally are used for E-waste recycling. The outputs from these processes are electronic components, plastics, glass, ferrous and non ferrous metals including precious metals.

The processes used by unorganized sector are manual dismantling, chemical treatment to extract non ferrous and precious metals and open burning. These processes produce air emissions, which may include dioxins due to open burning of plastics, highly acidic liquid effluents containing heavy metals due to chemical treatment to extract non ferrous metals and hazardous solid waste left after burning and chemical treatment of E-waste.

4. Measures to Control Pollution – Experience in developed countries regarding policy measures in controlling pollution from recycling industry showed the importance of enforcement of the regulations. In developing countries recyclers should follow strict regulations including air and water pollution control along with enforcement of the regulation should be strong enough to implement them effectively. In general, adoption of regulations and rigorous enforcement thereof are to be carried out in a manner prompted by individual pollution disputes.

If the intention to comply with the regulation is ensured by enforcement of regulations then the awareness of recyclers, information of pollution control technology including end-of-pipe technology and cleaner production technology should be provided by public authority or experts. Otherwise, they can not choose environmentally sound technology. Since such technology is expensive, recyclers may not afford installing pollution control equipment. If possible, low interest loan should be provided to small scale recyclers through industry associations, which can act as financial intermediary and a vehicle to disseminate information on the risks of pollution, the technologies and the financial options.

5. Conclusion – Recycling is considered to be good for the environment. But some material recycling processes cause environmental pollution, if proper pollution control measures are not applied. Relocation of the factory without any pollution control does not provide solution to the problem. If recycling plant is willing to invest in pollution control, information of pollution control technologies should be provided. If possible, financial support such as low interest loan can promote such investment.

References:

* Agrawal, A.; K.K. Sahu; and B.D. Pandey. 2004. “Solid Waste Management in Non- Ferrous Industries in India.” Resources, Conservation and Recycling 42: 99-120.

* Hishida, Kazuo. 1969. “Namari sai seiren sagyo ni tomonau haien no seijou to taisaku” (in Japanese) [Characteristics and control measures of emission from the process of recycling lead]. Taiki osen kenkyu [Journal of Japan society of Air Pollution] 4, no. 1, p. 81.

* Lal, Banwari, and M.R.V.P. Reddy, eds. 2005. Wealth from Waste. 2nd ed. The Energy Research Institute.

* Matsuda, Shozo; Masamichi Hara; Daihachiro Koyama; Hiroyuki Kitamura; Yoshihiro Nakagawa; Wataaki Takada. 1970. “Namari saisei kojo hansharo no baien chosa” (in Japanese) [Study on soot and dust from reverberatory furnace of lead recycling plant]. Excerpt from Report No. 1 of the Hyogo Prefectural Institute of Environmental Science.

* Milind, Wangikar. 2007. Presentation on “Copper Recycling Program” on behalf of International Copper Promotion Council (India) at India Copper Forum.

Reduction of use of energy for industrial purposes to mitigate CO2 emissions – Role of Material science is important:

Introduction – Rising population and increasing wealth are fueling growing global demand for products, services, buildings, and public infrastructure. The industrial sector, which manufactures these products and structures, has many opportunities to make them using less energy and emitting less carbon dioxide (CO2). Industry has a role in developing, producing, using, and recycling improved materials to manufacture products that consume less energy when used. Improved and modified materials should be stronger, lighter, better insulating, safer, better handling characteristics etc., than the earlier one.

Most industrial energy consumption occurs in industries that produce raw materials, such as chemicals and petrochemicals, iron and steel, nonmetallic minerals, and nonferrous metals. At present level, direct industrial CO2 emissions (excluding emissions from electricity generation and heat use) amounted to more than 6 gigatons. Three sectors were responsible for nearly 70% of the direct industrial emissions: iron and steel, nonmetallic minerals (notably cement), and chemicals and petrochemicals (this does not include the emissions from the freight transportation involved in bringing raw materials to manufacturing facilities and delivering products made from them to consumers, which would add another 10–12 percentage points). Thus, between one-third and one-half of global CO2 emissions are generated in activities related to materials and product supply.

Opportunities for energy efficiency vis-a-vis emissions – Globally, industry’s energy consumption and direct CO2 emissions have been growing. For the most part, growth in energy demand has been high in developing countries than in developed world. To some extent, growth in both energy demand and emissions has been mitigated by efficiency improvements in all sectors worldwide. However, these efficiency gains have not been geographically uniform. The rapid growth of production in less-efficient developing countries has contributed significantly to poverty alleviation, but it has also limited the average efficiency gains worldwide. Rapid growth in countries such as China and India has supported continuation of less-efficient heavy industry in some sectors that does not exist in developed countries. Small-scale manufacturing plants using outdated processes and low-quality fuels and feedstocks, as well as weaknesses in transportation infrastructure, contribute to industrial inefficiency in some emerging economies.

These overall energy and emissions trends can be mitigated through additional energy efficiency measures. Even though energy represents a manufacturing cost, to be managed and controlled like any other cost, industry is not always efficient in its energy use. Studies suggest that technical efficiency improvement potential of 18–26% for the manufacturing industry worldwide is possible if the best available technology were applied. Apart from savings, it reduces CO2 emissions substantially worldwide. Most of the underlying energy-saving measures would be cost-effective in the long term, but their implementation is hindered by the long remaining lifespan of the standing capital stock and the priority given to avoiding production disruptions that can be caused by new equipment or new procedures.

The realization of part of the potential for technical improvements would entail immediate significant costs because it would imply replacement of the existing capital stock before the end of its technical life. Over the longer term, however, these gains seem affordable. A key factor is the age of the capital stock. New plants tend to be more efficient than old ones, as more efficient technologies are developed and adopted. As a consequence, the most efficient industries can sometimes be found in emerging economies where production is expanding.

The discussion so far has focused only on technical potential, based on existing technology and current production volumes. Part of this potential will be realized by the market without new policy efforts. New CO2 policies might result in a greater uptake of these efficiency options, as well as in the use of further CO2 mitigation options that entail additional costs. In fact, incentive reflects a policy effort that can be based on a range of policy instruments such as taxes, subsidies, emissions trading schemes, sectoral agreements etc. A mix of CO2 emissions reduction incentives, efficiency regulations, and support measures would be needed. A range of new technologies plays a role in this scenario.

Discussion here focuses on three key materials industries—namely, iron and steel, cement, and chemicals and petrochemicals—providing some examples of the materials science, engineering, and management challenges of improving their energy efficiency and emissions performances.

a. Iron and steel – Steel is most important structural metal. Steel is used in a number of markets such as transportation equipment, infrastructure, machinery, buildings, and packaging. Taking into consideration the total world production of more than 1,3 billion tons of steel, the steel industry produces over two billion tons of CO2. In last three decades annual steel production grew more than 95%, while its energy use rose by about 30% and CO2 emissions increased by about 17% during the period.

Materials recycling reduce the energy needs and direct CO2 emissions substantially, by a factor of 2 to 4. Total scrap recovery in steel production increased substantially. Even though the recycling rate is high, an expanding economy has meant that the total crude steel production is roughly twice the amount of scrap collected and used. Materials losses from the lifecycle of steel are small, so increased recycling is an improvement option of secondary importance.

Materials properties enhancements are an important element of the steel industry’s effects on sustainability. Steel strength, quality, and other properties have a significant influence on how products made from steel use energy. For example, stronger steels allow for the use of thinner-gauge, and thus lighter-weight, product components. Reducing the weight of automobiles has received much attention and could yield 10– 15% fuel efficiency gains, provided that it is not offset by trends toward larger and higher performance vehicles. Improved collection and separation practices and processing technologies for scrap metal will allow further growth in the use of recycled steel in areas that have been the domain of virgin steel. In the case of coal-fired power plants, steel quality determines maximum operating efficiencies by limiting the temperatures and pressures in steam sections.

Not only steel quality but also coke quality is an issue that deserves attention. The impact of coke quality on coal and coke consumption in blast furnaces is still not well understood. Blast furnace operation is still largely based on engineering experience, and the impact of coal quality and ore quality on process operation cannot easily be transferred from one blast furnace to another. This limits the potential to translate the operating experiences of the best blast furnaces into a global improvement.

b. Cement – The cement industry contributes about 5% to global anthropogenic CO2 emissions, making the cement industry an important sector for CO2-emission mitigation strategies. Worldwide cement production is increasing with the vast majority of the production occurring in developing countries. China accounted for more than 47% of global cement production, whereas India, Thailand, Brazil, Turkey, Indonesia, Iran, Egypt, Vietnam, and Saudi Arabia together accounted for about 17%. Cement is a special case among major materials industries because more than half of its direct greenhouse gas (GHG) emissions emanate from process sources (the calcination of limestone during clinker production) rather than energy use, and these emissions cannot be reduced through changes in the process conditions.

Four approaches can be applied to increase the energy efficiency and reduce CO2 emissions in the cement industry:

(i) increase the process energy efficiency,

(ii) use coal fuel substitutes,

(iii) capture and store CO2 (an option for CO2 reduction only; not yet commercialized),

(iv) develop new cement types that reduce the use of cement clinker.

c. Chemicals and Petrochemicals – In last decades energy use in chemicals and petrochemicals production rose by more than 210% and CO2 emissions increased by about 160%. Certain inorganic chemicals such as fertilizers, chlorine, and soda have some energy relevance, but petrochemicals represent the bulk of the energy and feedstock use in this sector.

Materials substitution of biomass feedstocks for petroleum feedstocks holds great potential for reducing energy use in the petrochemicals industry. Interest in realizing this potential has risen, in tandem with the increased attention paid to the development of liquid biofuels stemming from surging oil prices, supply security considerations, environmental policies, and technological progress.

Detailed analyses show that bio- based chemicals offer substantial potential savings of nonrenewable energy and greenhouse gas (GHG) emissions. The bio-based chemical with the largest potential market is likely ethylene made from bioethanol. Bio-based ethylene can be used to produce bio-based polyethylene and all other bio-based ethylene derivatives such as ethylene oxide, ethylene glycol, or acetaldehyde; these, in turn, can be used for a wide range of chemicals such as polymers, solvents, antifreeze agents, and lubricants. It has been estimated that nonrenewable energy use and lifecycle GHG emissions can be reduced by more than one-third compared to petrochemical based approaches if ethylene is produced from bioethanol made from maize in a moderate climate and using the current level of technology. Using the same feedstock and more advanced fermentation and separation technology, the savings can be increased to 50%. Technically speaking, the overwhelming share of the total demand for organic chemicals and polymers could be covered from bio-based feedstocks.

Conclusions – Increasing the efficiency of industrial processes and the flows of materials through the economy is a slow transformation process that will take decades. In the short and medium term, it is important that new plants be built with the best available technology. Materials sciences will play a key role in the further development of emerging solutions for increased energy efficiency and reduced CO2 emissions.

Efforts to achieve deep GHG emission reductions will have significant consequences for materials use. About 36% of all CO2 emissions can be attributed to industry, mainly to materials production processes. Materials sciences can help to increase the efficiency of materials use and to develop new materials that allow for higher energy efficiency during product use.

References:

* Tracking Industrial Energy Use and CO2 Emissions. (IEA/OECD, Paris, 2007).

* D.J. Gielen, M. Taylor, Energy Econ. 29 (4), 889 (2007).

* J.-P. Birat, “DSTI/SU/SC” 68 (OECD Steel Committee Meeting, Paris, November 13, 2006).

* A. Fleming, Operation Maintenance and Materials Issue 1 (2) (2002).

* N. Lee, V. Sahajwalla, R. Khanna, B. Lindblom, M. Hallin, Proceedings Ishii Symposium on Sustainable Ironmaking, Sydney (Cooperative Research Centre for Coal in Sustainable Development CCSD, Brisbane, Australia, March 2–3, 2006).

* C. Shi, J. Mat. Civ. Eng. 16 (3), 230 (2004).

* H. Justnes, L. Elfgren, V. Ronin, Cem. Conc. Res. 35 (2), 315 (2005).

* K. Sobolev, T.R. Naik, CANMET/ACI Three-Day International Symposium on Sustainable Development of Cement and Concrete (Toronto, Canada, October 5–7. 2005).

* S.E. Laursen, J. Hansen, J. Bagh, O.K. Jensen, I. Werther (Ministry of Environment and Energy, Denmark, Danish Environment Protection Agency, Environmental Project No. 369, 1997).

* M. Patel, M. Crank, V. Dornburg, B. Hermann, L. Roes, B. Hüsing, L. van Overbeek, F. Terragni, E. Recchia, “Medium and long-term opportunities and risks of the biotechnological production of bulk chemicals from renewable resources—The BREW Project” (European Commission’s GROWTH Programme, DG Research, Coordinated by Utrecht University, Netherlands, September 2006).



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