World Energy Outlook 2007

There are a number of barriers to the widespread and rapid deployment of
CCS, which will need to be addressed if it is to make a major contribution to
mitigating energy-related CO 2
emissions, as in the 450 Stabilisation Case:
Commercial and financial issues: CO 2
must be given a value, either through
carbon taxation or the trading of emission credits.
Legal and regulatory issues: There is a need to establish legal guidelines with
respect to the injection of CO 2
, to define regulatory frameworks, to allocate
long-term liabilities and to develop risk-management procedures, including
monitoring and remediation (IEA, 2007b).
Technical issues: Capture technology needs to be improved in order to
improve reliability and lower costs. Potential leakage routes need to be
identified in different types of reservoir and long-term isolation procedures
established.
Public awareness: Key messages on CCS need to be effectively
communicated.
In addition to several national programmes, several international initiatives have
been launched, by both the public and private sectors, to study, develop and
promote CCS technologies. Given the magnitude of the challenges, including
the cost of research, development and demonstration, greater international cooperation
and sharing of best practices are required to accelerate the pace of
technology development and deployment (see Chapter 6).
Power-Generation Technologies
The combustion of pulverised or powdered coal to raise steam in boilers has
been the mainstay of coal-based power generation worldwide for almost a
hundred years. The efficiency of the current generation of pulverised coal
units has steadily improved and today ranges between 30% and 45% (on a
lower heating-value basis) depending on the quality of coal used, ambient
conditions and the back-end cooling employed. A number of advanced
power-generation technologies have been or are being developed to improve
thermal efficiency and to reduce other emissions, notably nitrogen oxides
(NO x
) and sulphur dioxide (SO 2
). These technologies hold out the prospect
of significantly raising the efficiency of the new coal-fired plants that will be
built in the coming decades and reducing their emissions (Figure 15.17).
The most important of current technologies and others in development are:
Supercritical and ultra-supercritical pulverised coal combustion: The efficiency
of a steam cycle is largely a function of steam pressure and temperature.
Typical subcritical steam cycles, as in the vast majority of today’s power
plants, operate at 163 bar pressure and 538°C. With supercritical designs,
220 World Energy Outlook 2007 - GLOBAL ENERGY PROSPECTS: IMPACT OF DEVELOPMENTS IN CHINA & INDIA