Coal Online Coal Online (c) IEA Clean Coal Centre This is an RSS feed. RSS feeds allow you to stay up to date with the latest news and features you want from the website. To subscribe to it, you will need a News Reader or other similar device. Coal and gas competition in power generation in Asia, CCC/246 by Nigel Dong & Paul Baruya Thu, 19 Mar 2015 09:12:52 GMT The emerging market for mercury control, CCC/245 by Dr L L Sloss Legislation for mercury control for coal-fired power plants is emerging in several regions. The US Environmental Protection Agency (US EPA) has several new rules, including MATS (the Mercury and Air Toxics Standard, 2014) and CSAPR (the Cross-State Air Pollution Rule, 2011) both of which will have a significant impact on coal-fired power plants in terms of retrofitting control technologies for compliance. Canada has the Canada-Wide Standard which sets caps on mercury emissions for individual Provinces. Although the EU has not yet set emission limits for mercury from coal-fired plants, the new IED (Industrial Emissions Directive) has annual monitoring requirements for mercury emissions. Further, the new BREFs (best available technology reference documents) include details on options for mercury control. This would imply that, although mercury is not currently being regulated, emissions are being monitored and control may be required at some sources in future. China’s latest Five-Year Plan (12th Plan, 2011-15) includes emission limits for mercury which, for the moment, are not particularly challenging. However, there is clearly a recent and significant move in China towards the cleaning up of emissions from the coal sector.

In addition to mercury-specific policies and approaches, these regions have other policies and regulations which could have a significant effect on mercury emissions. Looking ahead, based on the consideration that regulations will be enacted for several pollutants simultaneously in these regions, the outlook for environmental equipment regulations with respect to trace element emissions is investigated. The report covers:

• legislative approaches in the different regions
• suitable control technologies co-benefit approaches, mercury specific technologies and multi-pollutant strategies; and
• summaries of action in each of the target regions.

Wed, 04 Feb 2015 11:47:37 GMT
The direct injection carbon engine, CCC/243 Wed, 07 Jan 2015 12:12:14 GMT R&D programmes for clean coal technologies, CCC/244 by Anne M Carpenter Mon, 08 Dec 2014 10:15:11 GMT Increasing the flexibility of coal-fired power plants, by Colin Henderson Tue, 21 Oct 2014 16:03:45 GMT Techno-economics of modern pre-drying technologies for lignite-fired power plants, CCC/241 Wed, 24 Sep 2014 11:01:21 GMT Developments in oxyfuel combustion of coal, CCC/240 by Toby Lockwood Tue, 09 Sep 2014 15:59:55 GMT Prospects for coal and clean coal technologies in Turkey, CCC/239 Turkey has one of the world’s fastest growing economies. Rapid economic expansion, rising population, and growing industrialisation have triggered a general increase in energy demand.
During the last decade, natural gas and electricity requirements have soared. Over the next ten years, the current level of energy demand is expected to double. In order to meet this, significant investment in the energy sector will be required. 

Like many countries, Turkey faces energy supply issues. Indigenous energy resources are limited almost exclusively to lignite and smaller amounts of hard coal. As a result, there is a heavy dependence on imported sources of energy. More than 90% of Turkey’s oil and 98% of its natural gas is imported, as is much of the hard coal consumed. The cost is considerable, accounting for around a quarter of the country’s overall annual import bill. A major government objective is to reduce this, particularly through the greater use of domestic lignite, widely available in many parts of the country.

To help facilitate this, the government is pursuing a coal strategy and has introduced incentives to encourage the greater utilisation of this resource. Many new power generation projects are in the pipeline, a significant number fired on lignite. However, there are also a number of major projects that will rely on imported hard coal.

Many existing state-owned coal-fired power assets (and coalfields) are in the process of being transferred to the private sector. Some power plants require modernising and this is being factored into their selling price. The current coal-based generating fleet comprises plants based on conventional pulverised coal or fluidised bed combustion technology. Some newer projects plan to use supercritical steam conditions and all major power plants will be required to install effective emission control systems.

The further development and application of a range of clean coal technologies is being pursued by a number of Turkish utilities, technology developers, and universities. There is increasing involvement with international projects and, in many cases, growing links with overseas counterparts.

Thu, 31 Jul 2014 11:17:21 GMT
Blending of coals to meet power station requirements, CCC/238 Blending of imported and domestic coal is becoming of increasing importance. Until recently, coal blending in power stations was mainly adopted to reduce the cost of generation and increase the use of indigenous or more readily available coal. Low-grade (high ash) coal can be mixed with higher grade (imported) coal without deterioration in thermal performance of the boiler, thus reducing the cost of generation. With coal markets changing, new reasons for coal blending are becoming apparent. As indigenous coals become less available, of lower quality or more expensive to mine in some regions, blending of imported coals becomes necessary. It can be challenging to ensure that the resulting blend will maintain plant output without damaging the boiler. For example, in regions such as India the increased use of imported coals in boilers which have been designed for very different coal characteristics could lead to significant plant issues. 

It some cases coal blending is used as a form of pollution control, such as the combination of inexpensive high sulphur coals with more costly low sulphur coals to ensure compliance with sulphur emission limits. It is even possible to blend different coal types to maximise mercury reduction.

Many methods of coal blending are used. Coals can be blended at the coal mine, at the preparation plant, trans-shipment point, or at the power station. The method selected depends upon the site conditions, the level of blending required, the quantity to be stored and blended, the accuracy required, and the end use of the blended coal. Normally in large power stations handling very large quantities of coal, the stacking method with a fully mechanised system is followed.

This report discusses the different reasons and priorities for coal blending. It summarise the methods used in coal blending, from coal characterisation though to mixing and storage methods, including some case studies in challenging situations.

Thu, 31 Jul 2014 11:16:06 GMT
Non-fuel uses of coal, CCC/236 by Hermine Nalbandian Fri, 27 Jun 2014 11:22:07 GMT Coal sampling and analysis standards, CCC/235 by Qian Zhu Tue, 24 Jun 2014 15:12:05 GMT High temperature steels in pulverised coal technology, CCC/234 by Kyle Nicol Mon, 09 Jun 2014 10:28:23 GMT Coal reserves in a carbon constrained future, CCC/233 by Paul Baruya Energy reserves are quite well understood and have been recorded for many decades with varying degrees of accuracy. It appears that global reserves of coal could last in excess of 100 years, but this cannot be stated with absolute confidence. The life of coal reserves could face depletion in some parts of the world where production rates are high. Elsewhere, carbon onstraining legislation could depress demand, which could greatly extend the life of world coal reserves. Either way, the concept of supply and demand peaking will impact all coal producing and using countries eventually, but timing and extent of these peaks will differ. This report revisits analyses on fossil fuel depletion, and how various approaches to peak analysis and projections can impact the understanding of coal reserves.

Wed, 04 Jun 2014 11:24:14 GMT
High temperature steels in pulverised coal technology, CCC/234 by Kyle Nicol Pulverised coal combustion (PCC) power plant with supercritical (SC) steam parameters have been operational for forty years and ultra-supercrital (USC) PCC plant have been operational for just over twenty years. This significant amount of operating experience is valuable regarding the performance of high temperatures steels. For example 9-12% chromium martensitic steels have had problems with cracking and some have not been as strong as they were projected to be. Additionally, PCC power plant have been operated outside of design parameters, such as severe cyclic operation, which has resulted in unforeseen problems for high temperature steels. This report assesses the performance, problems, solutions and research efforts for high temperature steels used in SC and USC technology. ]]> Thu, 29 May 2014 14:58:15 GMT Developments in modelling and simulation of coal gasification, CCC/232 by Rohan Fernando In recent years, the considerable increase in the price of crude oil and natural gas and concerns about their security of supply focused attention on whether fuel for power production and feedstocks for the chemical industry could be obtained from the gasification of coal. The need to reduce greenhouse gas emissions has enhanced the prospects of power generation from Integrated Gasification Combined Cycle (IGCC) plant. However, the higher capital costs and concerns about reliability and availability of IGCC plant have limited their market penetration. The coal gasifier has been a significant source of operational issues.

A thorough understanding of the processes occurring in a gasifier is essential both for addressing existing causes of gasifier unavailability and improving designs for the future. Many complex processes take place in a gasifier and developing models of gasifiers results in a greater insight into these processes. Computational models in conjunction with plant data can be used to evaluate gasifier operation, solve operational problems, probe new designs and provide performance data for commercial scale-up. This report has surveyed models which are currently available for modelling gasifiers.

The report contains a brief description of the three types of gasifiers which are most commonly used. The models available for each type of gasifier are considered. Insight gained by modelling has advanced the
design of gasifiers and can improve gasifier performance. In some cases, the results have been compared with plant data and it has been possible to choose model inputs to give reasonable fit with
the measured data. However, there are fewer examples where modelling has directly solved operational problems.

Thu, 13 Mar 2014 14:02:22 GMT
Management of coal combustion wastes, CCC/231 by Xing Zhang Mon, 10 Feb 2014 10:09:03 GMT Sustainability of biomass for cofiring, CCC/230 by Deborah Adams Thu, 06 Feb 2014 09:47:47 GMT Coal prospects in Botswana, Mozambique, Zambia, Zimbabwe and Namibia, CCC/229 Mon, 06 Jan 2014 15:12:33 GMT Status of advanced ultra-supercritical pulverised coal technology, CCC/228 by Karl Nicol Fri, 20 Dec 2013 16:08:15 GMT Challenges and opportunities for coal gasification in developing countries, CCC/225 Fri, 29 Nov 2013 10:42:55 GMT Advances in multi-pollutant control Fri, 22 Nov 2013 09:17:02 GMT Techno-economic analysis of PC versus CFB combustion technology Mon, 18 Nov 2013 12:47:20 GMT Quantifying emissions from spontaneous combustion Tue, 29 Oct 2013 15:47:48 GMT Combining renewable energy with coal There are various possibilities for incorporating biomass into coal-fuelled processes and a number of these are already being deployed commercially. Others are the focus of ongoing research and development. Biomass materials can vary widely, although the present report concentrates mainly on the use of woody biomass in the form of forest residues. Potentially, large amounts are available in some parts of the world. However, not all forested regions are very productive, and the degree of commercial exploitation varies considerably between individual countries. The level of wastage associated with timber production and associated downstream processing is frequently high and considerable quantities of potentially useful materials are often discarded. Overall, forest residues are a largely underexploited resource.

Combining the use of biomass with coal can be beneficial, particularly from an environmental standpoint, although any such process may have its limitations or drawbacks. Each coal type and biomass feedstock has different characteristics although by combining the two, it may be possible to capitalise on the advantages of each, and minimise their individual disadvantages. An effective way is via cogasification, and useful operating experience has been achieved in a number of large-scale coal-fuelled gasification and IGCC plants.

Cogasification can be the starting point for producing a range of products that include synthetic natural gas, chemicals, fertilisers and liquid transport fuels. It also has the potential to form the basis of systems that combine coal and biomass use with other renewable energy technologies to create clean, efficient energy-production systems. Thus, various hybrid energy concepts, some based on coal/biomass cogasification, have been proposed or are in the process of being developed or trialled. Some propose to add yet another element of renewable energy to the system, generally by incorporating electricity generated by intermittent renewables such as wind or solar power. A number also aim to incorporate some form of carbon capture and storage.

Currently, not all such hybrid schemes have been fully developed and some may yet prove to be impractical or economically unviable. However, ongoing developments into areas, such as advanced gasifier and electrolyser design, is improving performance and driving down costs. The technology behind some proposed schemes appears to be sound and a number of these could have potential for deployment in the mid term.

Thu, 17 Oct 2013 15:21:43 GMT
Recent operating experience and improvement of commercial IGCC, CCC/222 by Ian Barnes IGCC has today reached a status where experience is available from first and second generation plants, built in the 1970s/1980s and in the 1990s respectively, as commercial-scale demonstration plants for coal-based applications. These plants feature variations on gasification technology and subsequent environmental controls and in operating them a number of technical and commercial lessons have been learned that will help to improve the next generation of IGCC projects. The report reviews and summarises the state-of-the-art and operating experience of several commercial IGCC plants worldwide, setting out the lessons learned and plans for future development embracing such issues as the changes or modifications to plant made to overcome the operational problems and to improve the reliability and availability of the plant. Since IGCC is considered a ‘capture ready’ technology for CO2 abatement, the current status with regard to the incorporation of carbon capture and storage systems (CCS) has been reviewed. Finally, the report outlines the issues associated with assessing the risks in commercialising IGCC plant.


Fri, 20 Sep 2013 10:04:03 GMT
Upgrading and efficiency improvement in coal-fired power plant, CCC/221 by Colin Henderson Improving the efficiencies of the large number of older coal-fired power plants operating around the world would give major savings in CO2 emissions together with significant other benefits. This report begins with a summary of the ways efficiency can become degraded and of the means available to combat the decrease in performance. These include improvements to operating and maintenance practices and more major techniques that are available, including boiler and turbine retrofits. There is also an update on fuel drying developments as a route to higher efficiency in plants firing high moisture lignites. The largest chapter of the report contains a number of descriptions of case study improvement projects, to illustrate measures that have been applied, benefits that have been achieved and identify best practices, which are summarised. Major national and international upgrading programmes are described.

Wed, 14 Aug 2013 15:17:46 GMT
Coal and gas competition in global markets, CCC/220, by Hermine Nalbandian and Nigel Dong Tue, 30 Jul 2013 09:33:11 GMT Developments in circulating fluidised bed combustion, CCC/219 by Qian Zhu sector, a significant minority of plant commissioned is based on circulating fluidised bed combustion
(CFBC). CFBC offers specific advantages over PCC, particularly in the utilisation of low quality
coals, and mixtures of coal with other fuels, including wastes. Since its initial deployment, CFBC has
continued to evolve. Recently, significant advances have been made in scaling-up the CFBC units and
in the adoption of supercritical steam parameters. The engineering designs and operation of the CFBC
systems have also been optimised leading to improvements in plant reliability and availability, and
plant economics. The CFBC technology is emerging as a real competitor to PCC system.
For PCC and CFBC boilers, oxy-fuel combustion systems that produce high purity CO2 exhaust
streams ready for carbon capture are under development. Oxy-CFB technology may have some
advantages over oxy-PC combustion designs but there are challenges in the development of the
concept and design of oxy-CFB boilers. This report reviews the recent developments in CFBC
technology and how it fits within carbon capture and storage strategies. ]]>
Tue, 02 Jul 2013 09:53:46 GMT
Recent developments in particulate control, CCC/218 by Kyle Nicol Electrostatic precipitators (ESP) are the dominant type of particulate control in pulverised coal combustion (PCC) plant; fabric filters (FF) play a smaller role. Environmental pressures and subsequent tighter regulations have lowered emission limit values (ELV) for particulate matter from PCC plant, and they are now extending to specific toxic metals, such as mercury. Lower ELV are generally met by increasing the efficiency of the existing particulate control via numerous enhancements. However, the existing fleet is ageing, various restrictions on site limit what work can be done and PCC plant is progressively operating under non-design conditions. Despite this, further developments in technology have led to significant improvements in collection efficiency and regulations have been met. New hybrid ESP/FF systems aim to become more viable than the individual technology by utilising the advantages of both technologies. The purpose of this report is to review the technical and economic considerations of enhancements in particulate control for PCC plant over the last decade.

Tue, 30 Apr 2013 10:07:32 GMT
Coal mine site reclamation CCC/216 by Lesley Sloss Coal mine sites can have significant effects on local environments. In addition to the physical disruption of land forms and ecosystems, mining can also leave behind a legacy of secondary detrimental effects due to leaching of acid and trace elements from discarded materials. This report looks at the remediation of both deep mine and opencast mine sites, covering reclamation methods, back-filling issues, drainage and restoration. Examples of national variations in the applicable legislation and in the definition of rehabilitation are compared.

Ultimately, mine site rehabilitation should return sites to conditions where land forms, soils, hydrology, and flora and fauna are self-sustaining and compatible with surrounding land uses. Case studies are given to show what can be achieved and how some landscapes can actually be improved as a result of mining activity.


Tue, 26 Mar 2013 15:32:37 GMT
Prospects for coal and clean coal technology in the Philippines, CCC/217 the increasing energy demand from a growing population are discussed. There is also analysis of the trends for coal demand and production, imports and exports of coal and the types of coal-fired power
stations that have been built. This includes examination of the legislation involving coal and the promotion of clean coal technologies. ]]>
Fri, 22 Mar 2013 14:58:10 GMT
Energy issues for Mongolia, CCC/215 by Andrew Minchener Mongolia is a very large, landlocked country, with a small population, located between Russia and China. In the last two decades, it has begun reforms to move from a centrally-planned economy towards one with market characteristics. At the same time, geological surveys have shown it is rich in natural resources, especially coal, copper and gold, as well as silver, uranium, molybdenum, iron, tin, nickel, zinc, tungsten, phosphates, fluorspar, and some oil. The Mongolia Government recognises that exploitation of its mineral wealth is essential if the economy is to grow; however, its GDP is too small to underwrite major investments to develop the mines and so there is a need for external assistance. This is creating problems as the government attempts to provide an attractive opportunity for external investors while maximising the material benefit to the country by establishing a stable process to manage mineral revenues for the public good. In order to both export the coal and use it within the country, there is a need to establish a major infrastructure development programme as well as reach an accord with China and Russia. The infrastructure needs include extensive rail/road links, an uprated and integrated power transmission and distribution grid, new power plant facilities, other industrial facilities, and townships in mining regions. It is essential that such developments should be undertaken with due regard for minimising environmental damage, to limit adverse impact on air quality in the cities, loss of water supplies and destruction of the fragile ecosystem. There are associated social problems, especially for the nomadic part of the population, as well as indigenous animal populations, both of whose migration routes are affected by some of the industrial developments. The country faces some difficult challenges with its need to establish mining-based commercial initiatives while at the same time seeking to establish a sustainable long-term future.


Wed, 27 Feb 2013 10:15:25 GMT
Public attitudes to biomass cofiring, CCC/214 by Rohan Fernando There is substantial interest in producing energy from renewable sources given the continuing concerns regarding climate change. One attractive renewable source for power generation is the use of biomass. Cofiring biomass is one of the simplest ways of reducing GHG emissions from coal-fired power plant. When doing so, in addition to addressing technical factors, it is important to consider public attitudes, as these shape government policies. Surveys of public attitudes to energy usually include renewable sources such as wind, solar and hydro. Bioenergy is sometimes included but cofiring seldom so. When assessing public attitudes, it is instructive to consider what information is freely available to the public. Hence information provided by major national or international organisations, either in favour or against cofiring, are described.

It is apparent that the public in most countries have little knowledge of bioenergy as a renewable energy source and most opinion polls do not even address the issue of the public’s attitudes towards it. The few polls that have been conducted indicate that solar, wind and hydro are much more popular than bioenergy. Bioenergy is more popular in countries such as in Northern Europe which have extensive experience in using wood products as an energy source. Opposition to cofiring biomass in coal-fired plant is mainly on the grounds of biomass availability and sustainability. The power industry publications concentrate on the technical issues for the plant when cofiring biomass rather than availability and sustainability concerns.

Mon, 25 Feb 2013 14:39:42 GMT
Gaseous emissions from coal stockpiles, CCC/213 by Xing Zhang Some methods used to prevent coal self-heating and spontaneous combustion can be applied to reduce emissions from coal stockpiles. ]]> Thu, 21 Feb 2013 11:22:12 GMT Support mechanisms for cofiring secondary fuels, CCC/211 by Nigel Dong Thu, 21 Feb 2013 11:17:17 GMT Coal losses in the supply chain, CCC/212 by Paul Baruya This report examines the way coal can change as it passes along the coal chain. A great deal of the change is intended, through separation and sizing, to ensure the coal being mined matches the specification demanded by the customer. This report attempts to identify these changes and presents some of the issues faced by the coal supplier and user. Much of the change leads to a loss of mass in the coal. Some of the coal is left in the ground (intentionally and unintentionally), while elsewhere, full extraction might occur with the addition of non-coal materials from the surrounding rocks. In both cases, the mined coal often requires further processing.

Coal processing by separation at preparation plants refines coal further and is where most of the mass loss occurs. Value is added by reducing ash content and improving heating value, thus providing a much more saleable product for the market. As soon as the coal leaves the mine, mass loss can occur either through natural deterioration of the fuel, through spillage or dust, or in extreme cases theft. In all cases measuring the amount of coal as it passes through the supply chain is required to verify that the coal reaching the consumer is of satisfactory quality and quantity. This can be done crudely by measuring stockpiles, to more sophisticated weighing systems at various points along the supply chain, and even measuring the volume held in a ship. Measurement is subject to error which must be minimised. Biomass needs to be processed in much the same way as coal, such as removing mineral matter and taking care in avoiding contamination

Mon, 18 Feb 2013 15:33:10 GMT
An early deployment strategy for carbon capture, utilisation, and storage technologies, CCC/206, by L D Carter This report describes the current use of CO2 for EOR, and discusses potential expansion of EOR using CO2 from power plants. Analysis of potential EOR development in the USA, where most current CO2-based EOR production takes place, indicates that relatively low cost, traditional sources of CO2 for EOR (CO2 domes and CO2 from natural gas processing plants) are insufficient to exploit the full potential of EOR. To achieve that full potential will require use of CO2 from combustion and gasification systems, such as fossil fuel power plants, where capture of CO2 is more costly. The cost of current CCUS systems, even with the revenue stream for sale of the CO2 for EOR, is too high to result in broad deployment of the technology in the near term. In the longer term, research and development may be sufficient to reduce CO2 capture costs to a point where CCUS would be broadly deployed. This report describes a case study of conditions in the USA to explore a financial incentive to promote early deployment of CCUS, providing a range of immediate benefits to society, greater likelihood of reducing the long-term cost of CCUS, and greater likelihood of broad deployment of CCUS and CCS in the long term. Additionally, it may be possible to craft such an incentive in a manner that its cost is more than offset by taxes flowing from increased domestic oil production. An example of such an incentive is included in this report.

Thu, 13 Dec 2012 10:50:22 GMT
Low water FGD technologies CCC/210 by Anne Carpenter Conventional flue gas desulphurisation (FGD) systems require large supplies of water. Technologies which reduce water usage are becoming more important with the large number of FGD systems being installed in response to ever tightening emission regulations. Reducing water loss is particularly important in arid regions of the world. This report reviews commercial and near commercial low water FGD processes for coal-fired power plants, including dry, semi-dry and multi-pollutant technologies. Wet scrubbers, the most widely deployed FGD technology, account for around 10–15% of the water losses in power plants with water cooling systems. This figure is considerably higher when dry/air cooling systems are employed. The evaporative water losses can be reduced by some 40–50% when the flue gas is cooled before it enters the wet scrubber, a common practice in Europe and Japan. Technologies are under development to capture over 20% of the water in the flue gas exiting the wet scrubber, enabling the power plant to become a water supplier instead of a consumer. The semi-dry spray dry scrubbers and circulating dry scrubbers consume some 60% less water than conventional wet scrubbers. The commercial dry sorbent injection processes have the lowest water consumption, consuming no water, or a minimal amount if the sorbent needs hydrating or the flue gas is humidified to improve performance. Commercial multi-pollutant systems are available that consume no water.


Wed, 05 Dec 2012 13:37:39 GMT
Coal-fired CCS demonstration plants, 2012, CCC/207 by Stephen Mills The present report reviews activities taking place focused on the eventual large-scale deployment of carbon capture systems on coal-fired power plants. With this aim in mind, there are three main CO2 capture technology streams currently being developed and tested; these comprise pre-combustion capture, post-combustion capture, and systems based on oxyfuel technology. Although numerous other capture systems have been proposed, these three are currently the focus of most RD&D efforts and this report concentrates on these. More speculative technologies still at early stages in their development are not addressed.

The overall aims of this report are to provide an update of recent technological developments in each of the main categories of CO2 capture, and to review the current state of development of each, primarily through an examination of larger-scale development activities taking place or proposed. However, where appropriate, data generated by smaller-scale testing is noted, especially where this is feeding directly into ongoing programmes aimed at developing further, or scaling-up the particular technology. Each is reviewed and the status of individual coal-based projects and proposals described. These are limited mainly to what are generally described as pilot and/or demonstration scale. Where available, learning experiences and operational data being generated by these projects is noted. Technology Readiness Levels (TRLs) of individual projects have been used to provide an indication of technology scale and maturity.

For pre-combustion capture, post-combustion capture and oxyfuel systems, an attempt has been made to identify the technological challenges and gaps in the knowledge that remain, and to determine what technology developers are doing in terms of RD&D to address these. However, issues of commercial confidentiality have meant that in some cases, information in the public domain is limited, hence it has only been possible to identify overarching aspirational goals, rather than to report on individual detailed research plans and proposals.

Mon, 19 Nov 2012 11:09:34 GMT
Trace element emissions from coal, CCC/203 by Hermine Nalbandian Trace elements are emitted during coal combustion. The quantity, in general, depends on the physical and chemical properties of the element itself, the concentration of the element in the coal, the combustion conditions and the type of particulate control device used, and its collection efficiency as a function of particle size. Some trace elements become concentrated in certain particle streams following combustion such as bottom ash, fly ash, and flue gas particulate matter, while others do not. Various classification schemes have been developed to describe this partitioning behaviour. These classification schemes generally distinguish between:

- Class 1: elements that are approximately equally concentrated in the fly ash and bottom ash, or
show little or no fine particle enrichment, examples include Mn, Be, Co and Cr.
– Class 2: elements that are enriched in the fly ash relative to bottom ash, or show increasing
enrichment with decreasing particle size, examples include As, Cd, Pb and Sb.
– Class 3: elements which are emitted in the gas phase (primarily Hg (not discussed in this review),
and in some cases, Se).

Control of class 1 trace elements is directly related to control of total particulate matter emissions, while control of the class 2 elements depends on collection of fine particulates. Due to the variability in particulate control device efficiencies, emission rates of these elements can vary substantially. The volatility of class 3 elements means that particulate controls have only a limited impact on the emissions of these elements.

Mon, 19 Nov 2012 11:09:16 GMT
Impacts of seaborne trade on coal importing countries - Pacific market, CCC/202 by Paul Baruya In recent years, there has been a convergence of international trade with traditional domestic markets. As imports continue to increase in many coal producing regions, the influence of trade on domestic markets has been twofold. Firstly, imported coal displaces domestic production and, secondly, international price trends may drive prices of what remains of the indigenous market for coal.

While international trade does not provide any additional benefits in terms of reduced CO2 at coalfired power stations, importing coal provides many benefits, such as cost savings, improved coal quality, enhanced supply diversity, and often fills a gap which domestic supply is unable to fulfil. This report examines how coal markets have evolved over the decades with utilities and heavy industry moving away from their seemingly secure yet captive markets of domestic coal to procuring more supplies from the international market to satisfy the need of cost reduction and better and consistent quality of fuel product. The various factors that have led to a rise in popularity of seaborne traded coal, and the future of domestically produced coal in the Pacific market are discussed.

This is in one of three reports which examine the changing trends in coal imports over the long term in three geographical regions: a global perspective, the Atlantic market and the Pacific market.

Tue, 23 Oct 2012 12:52:54 GMT
Hybrid carbon capture systems, CCC/204 by Robert Davidson In most discussions of systems for capturing CO2 from coal-fired power plants, three options are
described. These are:

post-combustion capture;
oxyfuel combustion;
pre-combustion capture.

Recently, some researchers have realised that it may be possible to pick and choose among the elements of the main CO2 capture systems and develop hybrid systems which are possibly cheaper and more energy efficient. The systems to be discussed in this brief survey include:

post-combustion capture with oxygen enriched combustion;
regenerable sorbents (calcium looping) with oxyfuel combustion;
post-combustion capture in IGCC plants;
gasification with oxyfuel;
gasification with chemical looping.
Most hybrid systems are at a very early stage of development compared with the conventional
methods with much of the research aimed at evaluation or modelling.

Thu, 18 Oct 2012 09:23:42 GMT
Understanding pulverised coal, biomass and waste conversion, CCC/205 by Ian Barnes Pulverised coal firing has been the dominant technology for generating power in utility boilers for almost a century. During this period, boiler designs have evolved through an accumulating collection of knowledge that has led to many empirical relationships that still guide current and future design directions to some degree. In the late 1940s the developed nations began to undertake coal research
based on scientific principles to ensure the most efficient use of the primary energy resource represented by coal. As the body of scientific knowledge on the physics and chemistry of coal combustion grew, it was used to direct the improvements to efficiency required and, later, the control of pollutants produced during the combustion of coal. This involves not only the control of emissions
of particulates, SOx and oxides of nitrogen but also of trace elements, polycyclic aromatic hydrocarbons and, increasingly, CO2. There have been a number of developments in the coal-fired power generation sector including cofiring with secondary fuels, particularly biomass and waste and the development of radically different combustion systems (for example, oxyfuel) to meet carbon
capture and storage requirements.

This report sets out the recent advances in this area of coal science and how they are being brought to bear on the current challenges in the field of pulverised coal combustion.

Mon, 01 Oct 2012 09:02:33 GMT
CO2 reductions from CCTs and CO2 capture, CCC/200 Colin Henderson and Paul Baruya The efficiency of a fossil-fired plant has a direct effect on its CO2 emissions. Efficiencies of coal-fired power plants vary considerably around the world, and there is a potential for major CO2 emissions savings by upgrading or replacements. This report provides estimates of the potential emissions savings through efficiency improvements and plant replacements using modern systems (clean coal technologies), for six coal-consuming countries. These are China, India, South Africa (non-OECD), the USA, Australia and the UK (OECD). In the future, CO2 capture and storage is likely to provide an economic means to reduce emissions further, and savings from this are also estimated.


Tue, 04 Sep 2012 08:54:03 GMT
Impacts of seaborne trade on coal importing countries - Atlantic market, CCC/199 Paul Baruya In recent years, there has been a convergence of international trade with traditional domestic markets. With imports increasing in many coal-producing regions, the influence of trade on domestic markets has been twofold: firstly, imported coal displaces domestic production, and in doing so, and secondly international price trends may drive prices of what remains of the indigenous market for coal.

While international trade does not provide any additional benefits in terms of reduced CO2 from coalfired
power stations, importing coal provides many benefits, such as cost savings, improved coal quality, enhanced supply diversity, and often fills a gap left by domestic supply. This report examines the various factors that have led to rise in popularity of seaborne traded coal, and seeks to discuss the future of domestically-produced coal in some of the major coal markets of the world.

This report, which concentrates on the Atlantic market, is one of three reports that examine how coal markets have evolved over the decades with utilities and heavy industry moving away from their seemingly secure yet captive markets of domestic coal to procuring more supplies from the international market to reduce costs and provide a better quality coal. The two sister reports look at the Pacific market and a global summary of international coal trade.


Thu, 26 Jul 2012 09:22:45 GMT
Impacts of seaborne trade on coal importing countries - global summary, CCC/197 Paul Baruya In recent years, there has been a convergence of international trade with traditional domestic markets, with import increasing into many coal producing regions, the influence of trade on domestic markets has been twofold. Firstly, imported coal displaces domestic production, and in doing so, secondly international price trends may drive prices of what remains of the indigenous market for coal. While international trade does not provide any additional benefits in terms of reduced CO2 at a coal-fired power stations, importing coal provides many benefits, such as cost savings, improved coal quality,
enhanced supply diversity, and often fills a gap which is left where domestic supply is unable to fulfil. This report examines the various factors that have led to rise in popularity of seaborne-traded coal, and seeks to discuss the future of domestically produced coal in some of the major coal markets of the world.

This report provides a global perspective of the changing trends in coal imports. Two separate reports provide more detail of the Atlantic and Pacific markets.


Mon, 02 Jul 2012 12:27:34 GMT
Carbon mitigation technologies in emerging technologies, CCC/198 by Andrew Minchener This report provides a review of the various options being pursued to reduce carbon intensities in five developing countries, namely Brazil, China, India, Indonesia and South Africa. These are major emerging economies, all of which are vulnerable to adverse effects from climate change, with their governments having to balance economic, environmental and social priorities. All have large carbon footprints; however, in each case, they have made commitments to reduce carbon intensities over the period to 2030 and, in some cases, beyond. The approach to be adopted varies from country to country, depending on both technical and economic drivers. China, India, Indonesia and South Africa have fossil fuel based economies, in which in three cases coal is the dominant energy source while for the other (Indonesia) coal is an important and growing component of the energy mix. In all four countries, while the introduction of renewable energy and nuclear power is being addressed to varying degrees, establishing higher efficiency coal-fired power plants is seen as an important and near-term step in reducing carbon intensities. At the same time, China, Indonesia and South Africa have shown interest in CCS as a future mitigation option, with government policies identifying it as a key development priority. In contrast, in India, there is at present little interest in the technology. In the case of Brazil, the very different energy mix compared to the other four countries means that there is little interest in CCS for the power sector since that is dominated by renewable energy use. However, while there is a lack of policies to support CCS, the government's limitations on CO2 release from oil and gas extraction from the newly discovered deposits has provided a powerful driver for CCS related R&D. Following a description of the respective programmes, suggestions are made on the need to accelerate the development and deployment of CCS technologies, especially in those developing countries that have established policies to counter climate change and have recognised the potential importance of CCS as a carbon mitigation technique. It is also suggested that it is important to support the nearer-term but equally critical initiatives to establish higher efficiency and cleaner coal units for power and non-power applications.


Mon, 02 Jul 2012 12:19:14 GMT
Legislation, standards and methods for mercury emission control, CCC/195 Lesley Sloss Mercury is an element of growing global concern. The United Nations Environment Programme plans to finalise and ratify a new global legally-binding convention on mercury by 2013. Canada already has legislation on mercury emissions from coal-fired utilities and the USA has recently released the new Mercury and Air Toxics Standard. Although other countries may not have mercury-specific legislation as such, many have legislation which results in significant co-benefit mercury reduction due to the installation of effective flue-gas cleaning technologies.

This report reviews the current situation and trends in mercury emission legislation and, where possible, discusses the actions that will be taken under proposed or impending standards globally and regionally. The report also reviews the methods currently applied for mercury control and for mercury emission measurement with emphasis on the methodologies most appropriate for compliance. Examples of the methods of mercury control currently deployed in the USA, Canada and elsewhere are included.
Wed, 11 Apr 2012 11:11:29 GMT
Cofiring high ratios of biomass with coal, CCC/194 Rohan Fernando As concerns regarding greenhouse gas emissions from coal-fired power plant increase, there is greater focus on the feasibility of cofiring high ratios of biomass. This report first addresses the technical issues which arise when cofiring biomass at high ratios in coal-fired power plant. These principally concern the availability of fuel, storage and handling, milling, slagging, fouling, corrosion and ash disposal. It then describes experience of power plant which have cofired high ratios of biomass over extended periods. These plant are located mainly in the Netherlands and Denmark and a few in the USA, Finland, Belgium and the UK. The report also briefly assesses issues arising when repowering a coal-plant to fire 100% biomass.


Tue, 13 Mar 2012 16:04:32 GMT
CO2 abatement in the iron and steel industry, CCC/193 Anne Carpenter emissions from raw materials preparation (coking, sintering and pelletising plants) through to the production of liquid steel in basic oxygen furnaces and electric arc furnaces. Direct reduction and smelting reduction processes are covered, as well as iron making in a blast furnace. A range of technologies and measures exist for lowering CO2 emissions including minimising energy consumption and improving energy efficiency, changing to a fuel and/or reducing agent with a lower CO2 emission factor (such as wood charcoal), and capturing the CO2 and storing it underground. Significant CO2 reductions can be achieved by combining a number of the available technologies. If carbon capture and storage is fitted than steel plants could become near zero emitters of CO2 ]]> Tue, 13 Mar 2012 13:36:52 GMT Pre-combustion capture in CO2 IGCC plants, CCC/191 Robert M Davidson Pre-combustion capture involves reacting a fuel with oxygen or air and/or steam to give mainly a ‘synthesis gas (syngas)’ or ‘fuel gas’ composed of carbon monoxide and hydrogen. The carbon monoxide is reacted with steam in a catalytic reactor, called a shift converter, to produce CO2 and more hydrogen. CO2 is then separated, usually by a physical or chemical absorption process, resulting in a hydrogen-rich fuel which can be used in many applications, such as boilers, furnaces, gas the use of pre-combustion capture in coal fuelled integrated gasification combined cycle (IGCC) plants. After the introduction there follows a short discussion of the water-gas shift (WGS) reaction. This is followed by chapters on the means of CO2 capture by physical and chemical solvents, solid sorbents, and membranes. The results and conclusions of techno-economic studies are introduced followed by a look at some of the pilot and demonstration plants relevant to pre-combustion capture in IGCC plants.

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Wed, 15 Feb 2012 11:59:14 GMT
Prospects for coal and clean coal technologies in Kazakhstan, CCC/192 Morel Oprisan The coal sector in Kazakhstan is said to have enough reserves to last over 100 years, but the forecasted reserves are expected to last several hundreds of years. This makes investing in the fuel and energy sector of the country an attractive option for many international and private organisations. The proven on-shore reserves will ensure extraction for over 30 years for oil and 75 years for gas. The future development of the domestic oil sector depends mainly on developing the Kazakh sector of the Caspian Sea.

The coal sector, while not a top priority for the Kazakh government, puts the country among the world's top ten coal-rich countries. Kazakhstan contains Central Asia's largest recoverable coal reserves. In future, the development of the raw materials base will be achieved through enriching and improving the quality of the coal and the deep processing of coal to obtain fluid fuel and synthetic substances. Developing shale is also topical. The high concentration of methane in coal layers makes it possible to extract it and utilise it on a large scale.

However, today the country's energy sector, which was largely established in the Soviet times, has reached its potential. Being alert to the impending problems, the government is planning to undertake large-scale modernisation of the existing facilities and construct new ones during 2015-30.

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Wed, 25 Jan 2012 10:19:29 GMT
Upgrading and improving efficiency of coal-fired power plant Upgrading and improving efficiency of coal-fired power plant, Melbourne, Australia, 19-20 April 2012 ]]> Wed, 01 Jun 2011 12:11:38 GMT