POWER July 2017 - 48

ENVIRONMENTAL TECHNOLOGY
2. Double the heat. Units 3 and 4 at the Guodian Taizhou Phase II Project, which came
online between September 2015 and January 2016, demonstrated Chinese-designed and supplied
double-reheat ultrasupercritical technology. The calculated coal consumption at the $1.27
billion project is 256 grams of coal-equivalent per kilowatt-hour. Courtesy: China Guodian Corp.
expand the use of air-cooled thermal power
technology since around 2005. An indigenously
built 600-MW air-cooling system
was scaled up to a 1-GW ultrasupercritical
air-cooling unit and installed at the Huadian
Ningxia Lingwu Power Plant in Northwest
China in 2010. The technology now reportedly
equips 66 GW of China's fleet.
Particulate Matter Control Technolofollowing
efficiency standards or shut down:
300 [g/kWh] for all new plants and 310 [g/
kWh] for all existing plants. " The 100 most
efficient coal-fired power plants in China
range from 271.56 [g/kWh] to 294.88 [g/
kWh]. " No plant on the U.S. top 100 list can
currently meet these efficiency standards, "
the authors noted.
A Technology Vision
According to Qian, achievements in efficiency
have also been driven in large part by
China's giant investments in research and development
(R&D) of new technologies and
processes. Strategic objectives set out in its
11th Five-Year Plan (2006-2010), 12th FiveYear
Plan (2011-2015), and 13th Five-Year
Plan (2016-2020) prioritized technology development
for large-scale ultrasupercritical
and CFB units, as well as for carbon-capturing
integrated gasification combined cycle
(IGCC) units. These comprehensive plans
also take into account domestic intellectual
property rights and funding initiatives.
The result: China has both adapted and
improved on technologies developed abroad,
but also achieved cost reductions through
process innovation, incremental manufacturing,
and deployment at scale. But China's
development of domestic technologies and
optimized engineering designs that are applicable
to various parts of its power generation
process, on both new and existing power
plants, are also laudable. Some examples of
significant progress follow.
Double-Reheating Ultrasupercritical
Technology. A noteworthy example is the
Guodian Taizhou Phase II Project, an ultrasupercritical
plant consisting of two 1,000-MW
units put online between September 2015 and
January 2016 that demonstrated indigenously
designed double-reheat technology (Figure
2). Compared to a conventional gigawatt-lev48
el
single-reheating unit, the double-reheating
unit adds another level of reheating to allow
the system to reach a higher thermal cycle efficiency,
adding to gains in power generation
efficiency while slashing coal consumption
and generation costs, says the plant's owner
China Guodian Corp. Unit 3 has a plant
efficiency of 47.82%, one of the highest in
China and in the world, and its emissions of
PM, SO2
and 31 mg/m3
, and NOx are 2.3 mg/m3, 15 mg/m3
, respectively, noted Qian. The
,
demonstrated technology has since been applied
to at least two other power plants.
Circulating Fluidized Bed Technology.
China now has a total of more than
3,000 CFB boiler units, a technology that
suits China's high-sulfur coal resources. In
2013, China commissioned the 600-MW
supercritical Baima CFB demonstration
power plant, which continues to be one of
the largest units of its type. The steam parameters
adopted by the Baima CFB unit
are 25.4 MPa/571C/569C. The emissions of
SO2
, NOx, and PM (192, 112, and 9 mg/m3
,
respectively) are reportedly much lower than
designed values for burning low-quality coal.
Integrated Gasification Combined
Cycle Technology. Also in 2013, China
put online its first IGCC plant, the 250-MW
Huaneng Tianjin demonstration plant (Figure
3). The project in Tianjin province uses subbituminous
coal. The gasifier is a dry-feed,
oxygen-blown, pressurized two-stage reactor.
Modifications in 2014 improved project
reliability and availability significantly, said
the plant's majority owner, China Huaneng
Group. In July 2016, the plant's owners
completed 72 hours of continuous operation
during full-load commissioning tests on the
carbon capture system, which uses an absorption
chemical solvent-based process.
Air-Cooled Power Plants. In response
to water scarcity, China has sought to vastly
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gies. China's strong concerns about its widespread
fine particulate issues have spurred a
number of innovations. According to the Chinese
Academy of Engineering, researchers at
Tsinghua University have developed novel
technologies, including in situ low-intensity
phase-selective laser-induced breakdown
spectroscopy, an in-flame two-stage diluted
sampling system, and a thermophoretic sampling
system to tamp down ultrafine PM
formation at an early stage of the pulverized
coal combustion process for plants burning
high-sodium lignite and anthracite coal. The
academic institution also says that stricter
emission standards have prompted the use of
" multi-field coupled control technologies, "
including hybrid conventional approaches
involving acoustic force, electrostatic force,
chemical bonds, and thermophoretic force.
These technologies are used alongside the
widely applied use of wet ESPs, low-temperature
ESPs, and hybrid ESP/bag systems.
Carbon Capture, Utilization, and Storage
(CCUS). China's commitment under
the Paris Agreement is to reduce its carbon
intensity 60% to 65% from the 2005 level
by 2030, peaking its carbon emissions by
2030, and boosting the share of non-fossilfueled
power to 20%. In 2012, China became
the world's largest emitter of greenhouse
gases-responsible for 23% of the global
total. The country has been exploring a number
of ways to capture CO2
, including with
precombustion methods such as the GreenGen
IGCC project. It has so far completed
three demonstration post-combustion carbon
capture projects. In 2014, it also put online a
35 MWth oxyfuel boiler in Hubei province
as part of a long-term plan to launch oxyfuel
boilers of 200 MW to 600 MW after 2020.
That project is supported by the Huazhong
University of Science and Technology, along
with a number of power generators and plant
equipment makers. Projects are also underway
to explore deep saline aquifer carbon
storage, micro algae cultivation, and for
long-term enhanced oil recovery. According
to experts, China is on track to demonstrate
the entire CCUS process and is determined to
accelerate its commercial application.
Prospective Technologies
A number of initiatives are ongoing in parallel
to develop even higher-efficiency power
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