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9 April 06 RMJMM Draft

20th World Energy Congress - Rome 2007

    "Energy Future in an Interdependent World"

    Emerging Changes

    in the Worldwide Power Sector:

    The Assets of Thermal Power

    Michel Molière, Amélie Girardot, Robert M Jones

    GE Energy

ABSTRACT

In forthcoming decades we will see major changes in the landscape of the worldwide power

    sector as CO management and incipient hydrocarbon scarcity exert their increasing influence. 2

    The power generation community must be prepared to satisfy a particularly complex and

    challenging set of requirements. These issues include curbing CO emissions, coping with 2

    surging primary energy prices, and compliance with regional and local emissions

    requirements such as SOand NOwhile maintaining maximum efficiency. x x

In this context, as confirmed by International Energy Agency forecasts, thermal power will

    maintain a prominent position in overall power generation since it enables the large capacity

    additions required in emerging countries. Thanks to their reliable assets (such as energy

    efficiency and environment) gas turbine-based power systems, including Gas Turbine

    Combined Cycles (GTCC) and Combined Heat & Power (CHP), will continue to be major

    contributors to worldwide power generation. However, evolving changes in the spectrum of

    fuels will create an additional challenge for power generation equipment manufacturers

    requiring innovative technologies in fuel processing, combustion, and emission controls to

    address these needs.

This paper reviews the factors underlining the changing power generation environment

    worldwide, including the increasing scarcity of conventional fuels and the growing interest in

    biofuels and hydrogen. Insights will be offered into various technologies needed to support

    the growing need for increased fuel flexibility.

th20 World Energy Congress Rome 2007 1

INTRODUCTION

    In the coming decades the energy landscape will experience major changes for which the

    world community must prepare. Past decades have seen a period of low cost energy and

    sustained growth that has benefited the power market, with ample movement for new plant

    erection worldwide. Electrification has gained ground in developing countries while aging

    power plants have been replaced with more efficient units. Gas Turbine Combined Cycle and

    Cogeneration (GTCC) Units have demonstrated their potential in a number of regions where

    natural gas (NG) and gas turbines have acquired the lion’s share of the market within a win-win game. This accelerated growth has allowed decisive progress in gas turbine technology,

    with the typical efficiency of GTCC climbing from 50% to 56%+ over this period.

The way ahead seemed straightforward, driven by a quest for higher efficiency and lower

    emissions targets. However, awareness of the fragility of the gas market remained a constant

    backdropand this threat was amplified by some worldwide events during the 90s. At the

    same time the harmful effect of greenhouse gases on the global climate was gaining credence

    in scientific circles, resulting in the Kyoto protocol being adopted under the “principle of precaution.” Nevertheless, increasing energy conversion efficiency was still considered as the

    only means of keeping the CO

     issue under control. Today both the geopolitical issues posed 2

    by primary energy supplyand the global challenge created by climate changesare not only recognized by experts, but also perceived as realities by the public at large; addressing

    them is a must for both political and economical factors.

On one hand, the price of natural gas is surging, with a coupling mechanism between the

    three main fossil energies. On the other hand, conversion efficiency is no longer considered

    sufficient to curb the deleterious effects on climatewhile the ability to capture CO

     has 2

    become a must. This has prompted a number of countries to promote measures that

    encouraged the use of biomass, the adoption of “Energy Trading Schemes,” and the

    implementation of Renewable Obligation Certificates (ROCS).

    In the increasingly complex and changing world of the power community, all stakeholders of

    the energy world need to seriously consider the power systems of tomorrowin which

    primary energy considerations and environmental concerns will become critical. In this

    context, there is no doubt that the quest for alternative energy sources will be a key necessity.

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This paper offers a preliminary analysis of the factors shaping the world power scene of

    tomorrow, while emphasizing the assets of the next generation of thermal power plants.

    I. THE EQUATIONS OF TOMORROW’S POWER SECTOR

Energy and power are strongly interrelated worlds. In the near future, both the power and

    energy scenes are expected to experience major changes due to a number of internal and

    external constraints (Figure 1). This creates a vital need to identify the traits that future power

    generation plants must acquire in order to “survive the game.”

    ? GENERAL ELECTRIC COMPANY

    Figure 1. The Hexagon of Constraints

1. A Carbon-Constrained World

    The world is commencing an irreversible move towards an increasing scarcity of fossil

    energy as a result of the aggravating imbalance between limited supply and rising demand.

    The International Energy Agency (IEA, World Energy Outlook 2006) forecasts that in the

    next decades, fossils fuels will remain indispensable to fulfill power-generation demand,

    before they are partly displaced by non-fossil sources. This revolution, never experienced

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before, will cause a regular increase in energy prices. This will combine with fast-paced

    developments occurring in some emerging countries that still have highly energy-intensive

    economies. Such unprecedented accelerations of demand will in turn foster an increasingly

    volatile energy market. Not only oil, but all fossil energies (including natural gas and to a

    lesser extent, coal) will actually experience this pressure. This presents a challenge to all

    strategic projections for the security of supply and worldwide economic competitiveness.

2. Climate Change

    A second overwhelming constraint is represented by the global climate changes that are

    increasingly recognized as a major challenge by the scientific community. International

    organizations are prompting initiatives such as the Kyoto protocol and the Emission Trading

    System (ETS). While these measures to curb CO

     emissions generate new regulatory 2

    constraints, they also create new opportunities for power generators. These two major

    constraints will converge to create a carbon-constrained environment.

    3. Globalization of the Energy Market

    A third factor is related to the globalization process. Where energy and power are concerned,

    globalization means the liberalization of trade and transportation of electricity and fuels.

    Where the natural gas market is concerned, a harmonization effort is required to create a

    “uniform, single specification commodity” with large composition specifications that can be

    used for cross-border trading between delocalized suppliers and large GTCC owners. This

    generates an unprecedented fuel flexibility constraint.

    4. Economy’s Competitiveness

    In every country, the economy has a vital need for competitiveness. Both large manufacturing

    industries and small/medium enterprises want reliable and low cost kWh, which tends to

    prolong the use of ageing, paid-off power units or promote new ones that must successfully

    compete with the former to carve out their place. As is often the case, a combination of

    innovative and proven technology features can result in a strategic breakthrough.

    5. The Weight of Public Opinion

    As a fifth important effect, public opinion plays a major role in energy policiesinfluencing

    site selection and permitting for new power plants, while increasingly determining the

    preferred power technologies of the future.

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6. Air Quality: Non-CO Emissions 2

    The control of non-CO emissions is another challenge that must be overcome. In many 2

    urbanized places, there is a need to improve the quality of the air along with a need to keep

    pristine areas under protection. This requires controlling local emissions such as UHC, VOC,

    ozone, Poly-Aromatic Hydrocarbons (PAH) and Particulate Matters (PMs) that act

    synergistically as allergenic and carcinogenic compounds. Long distance, cross-border

    pollutants such as SO and NO that are responsible for the acid rains must also be reduced. xxTherefore, the control of noxious emissions will remain as a major battlefield.

7. Winners’ Profile

    Which strategy is inspired by the “hexagon of constraints?” Tomorrow’s successful power

    generation schemes will be the ones that best accommodate the complex, often conflicting set

    of requirements previously described. To cope with the overwhelming limitations created by

    a carbon-constrained market and a volatile energy market, the competing technologies will

    have to reach new heights of efficiency and flexibility. In this regard, the word “flexibility”

    (often used as a mere synonym for flexible operation) must be understood as a many-faceted

    concept that prevails throughout all project phases and over the product life. In thermal plants,

    fuel flexibility is a major dimension of flexibility and it is in this area that gas turbine-based

    generation (CHP and GTCC) can bring a prominent contribution. To fully understand the

    stakes of fuel flexibility in thermal generation, an insight into the cluster of primary energies

    is a necessity.

II. THE PRIMARY ENERGIES OF TOMORROW : AN OVERVIEW

As previously emphasized, fossil fuels will remain essential contributors to the cluster of

    primary energies for power generation in the next two decades. It is therefore of prime

    interest to first summarize the prospects offered by conventional energiesand then to

    analyze their respective benefits and limitationsbefore looking at the possible substitutions.

    1. Outlook for Conventional Primary Energies Natural gas has achieved a major penetration in the power market. The strong match between

    cleaner attributes of natural gas and the inherent qualities of advanced gas turbines account

    for the unrivalled performance demonstrated by GTCC plants in terms of efficiency,

    Reliability-Availability-Maintainability (RAM) and emissions. On a global scale this success

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is expected to continue to a large extent into the forthcoming decades. However, the rush

    towards natural gas that was experienced worldwide during the 90sand in the US during

    the early 2000shas placed considerable pressure on the supply side; and the threat of

    uncontrolled volatile pricing or excessive energy dependency causes increasing concerns

    among planners.

First, natural gas resources are unequally distributed: for instance, Asia, which is expected to

    be responsible for 50% of the increase in energy consumption through the year 2020, has

    access to only 7% of the global gas resources. Many world consumers have a strong

    dependence upon their suppliers. Therefore, despite the intense development of liquefied

    natural gas (LNG) facilities in the Middle East and erection of LNG terminals in the US, EU,

    Japan and recently in China, this energy source is unlikely to meet all demand forecasts.

    Additionally, with the prospect of an increasing paucity of carbon and the rising

    interrelationship observed between the oil and gas markets, there is a growing impression that

    the success of natural gas is not sustainable.

Finally, despite its numerous advantages, by itself natural gas does not fulfill zero-CO

     2

    emission and requires CO capture, as do the other primary energies. 2

    As far as the oil sector is concerned, a real decline in the weight of petroleum products in power generation has already been observed. This is because this market is increasingly

    driven by a “huge transportation sector” with most domestic refining facilities struggling to

    match the strong demands for light/middle automotive distillates. Therefore the precious,

    expensive distillates are unlikely to help satisfy a substantial portion of power needs. The

    combustion of increasingly difficult heavy oils in thermal plants raises issues primarily

    related to emission control. Currently, gasification of residuals or petroleum coke is the sole

    technology that is able to convert low or negative-value carbon to cleaner power. This

    technology will be further reviewed in Section III.

Coal is the most abundant and traditional fuel worldwide. According to the IEA, fossil carbon

    resources such as coal and lignite will be available for a long period of time, in the range of

    400 years. In some EU countries such as Germany, the UK, and Poland where it has been a

    major natural resource, coal has long been a prominent energy source for poweralthough it

    has recently been dethroned by natural gas in new plants. This contrasts with other world

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     regions such as the USA, Australia, China and India where coal is still considered as the

    primary contributor for future base-line electricity production. From the prospective of

    efficiency and environmental protection, Integrated Gasification Combined Cycle (IGCC)

    coal combustion appears as a promising and proven technological solution for long-term

    power needs. This point will be discussed further in Section III.

Finally, for several related reasonspublic opinion, investment cost and project cyclethe

    contribution of nuclear power is expected to increase at a very modest rate in the EU (except

    in France where it has gained public acceptance after over three decades of experience. In

    light of this short, simplified analysis, resorting to alternative energies appears as an

    increasing necessity.

2. Alternative Fuels

    In a changing landscape of energy supply, the power energy community of the future will

    increasingly call on alternative fuels, while capitalizing on the experience gained in this field

    during the past decade. In particular, gas turbines have demonstrated, as continuous-flow

    machines, distinctive capabilities to accept a wide variety of fuel. Indeed, their robust designs

    and universal combustion systems enable heavy-duty gas turbines to handle a vast range of

    fuels. Consequently, gas turbines that run on alternative fuels and are deployed either in

    GTCC or CHP plants, can greatly contribute to large savings of fossil fuels.

Figures 1 to 3 offer synoptic representations of gaseous and liquid alternative fuelswhile

    showing the vast panorama of alternative fuels that have been successfully explored by

    heavy-duty gas turbines.

     In this paper, it is indeed important to distinguish three classes of

    alternative fuels (see the table in Appendix 1): ? The first category stems from industry process and ultimately derives from the Oil and

    Gas or steel sectors; many of these fuels like “fuel gases” cannot be transported or even

    storedand exploiting this fuel vein will be of interest essentially to minimize fuel

    supply in industrial plants in the carbon-constrained environment.

    ? The second category (syngas and synfuels) directly derives from fossil carbon (coal,

    lignite, sand shale oil) which is available in abundance and represents a great potential

    within the carbon-constrained economy provided they are subjected to carbon capture.

    ? The third category derives from biomass, which is distributed around the world and is

    also of prime interest due to its overall neutral carbon balance.

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For the purpose of developing power at a worldwide scale, the second and third categories

    represent a potentially abundant supply and offer the most promising prospects. From a

    technical, economical and environmental viewpoint, IGCC technology offers a very

    consistent approach to the cleaner conversion of combustible solids into electricity, especially

    at a large scale. Gasification is a form of oxidation performed under pressure by a mixture of

    an oxidantand applies not only to coal or lignite but also to viscous residual fuel oils (RFOs), biomass (wood, straw, vegetables), and even to municipal wastes.

III. FOCUS ON GASIFICATION PRODUCTS

In many countries, coal and lignite remain an important portion of their energy portfolio and

    will continue to play a crucial role as an energy provider for the foreseeable future.

    1. The Power of IGCC The Integrated Gasification Combined Cycle option can fulfill the “equations of tomorrow’s

    power generation” previously analyzed. IGCC actually combines:

    ? Fair conversion efficiency

    ? Primary energy security (since coal has an even geographic distribution worldwide)

    ? Cost effectiveness

    ? Strict control of non-CO

     emissions and CO when combined with CCS 22

    ? Fuel flexibility

    IGCC also provides the advantage of a versatile multi-generation capability: power, heat,

    hydrogen and carbon-chemistry derivatives such as methanol or synfuels. These advantages

    also apply to other, low-valued opportunity fuels such as residual oilsas IGCC has

    successfully demonstrated over a wide variety of fuel applications.

    IGCC plants with GE gas turbines (operating or under contract) combine for a total of more

    than 2,500 MW. Another total of 1,020 MW is operating (or on order), using process fuels

    from steel mills. This machine fleet has accumulated a total of more than 850,000 hours of

    operation on low-calorific syngas fuels, as well as significant operation with co-firing of

    alternative fuels. Several recent refinery-based IGCC projects boast exceptional performance

    and fuel flexibility. Current applications include grass roots power and re-powering,

    cogeneration, co-production of chemicals and hydrogen, and varying levels of process

    integration. Process feedstock includes coal, lignite, petroleum coke, heavy oil, and waste

    materials converted by six different gasifier types (see Appendix 2).

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     IGCC’s high marks in environmental performance derive from both the fundamental

    characteristics of the process and enhancements in gas turbine combustion. Future IGCC

    upgrades are ensured by its capability to meet outstanding performance for heavy metals

    (including mercury), PAH and particulate removal.

2. Carbon Capture and Storage

    Pre-combustion de-carbonization applied to IGGC or natural gas-fired GTCC plants

    represents the preferred method for carbon capture and sequestration (CCS), approaching

    towards near-zero CO

     emission. For natural gas, the approach is methane reforming, 2

    followed by a water shift and scrubbing of CO. In IGCCs this approach benefits from a 2

    number of advantages as shown in Figure 2:

    ? Carbon compounds to be captured are in high concentration in the fuel stream

    ? The fuel already has been substantially reformed (i.e., transformed into CO + H), so that 2

    only a water shift (i.e., transformation into CO + H in presence of steam) is necessary 22

    prior to acid gas removal

    ? The syngas volume is reduced due to elevated pressure gasification

    Finally, in both cases the combustion of near-pure hydrogen benefits from existing gas

    turbine experience on high hydrogen fuel derived from process plant applications.

    Figure 2. Pre-combustion CO? GENERAL ELECTRIC COMPANY

     Capture 2th20 World Energy Congress Rome 2007 9

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