Coal Combustion Residue True Cost Investigation
There are speeches by both Black & Veatch and
SEFA at Power-Gen
relative to beneficially using ponded
flyash. Burns & McDonnell has a stand and a
meeting with Patricia Scroggin Wicker is
scheduled. It will be an open discussion for any
attendee. It is scheduled for 2 PM on Tuesday
but check updates for changes.
Patricia was interviewed on this subject
two years ago.
Meeting the new ELG and CCR requirements-
options explained by Patricia Scroggin
Patricia Scroggin, currently a regional practice
manager at Burns & McDonnell, explained the
options for meeting the CCR and ELG
requirements. Bottom ash choices include: the
remote chain conveyor which does not require
modifications at the boiler but is high in
capital cost, and the Magaldi dry cooler which
has the advantage of being a dry system but can
provide a problem in trying to locate it under
the boiler. The pneumatic ash extractor,
dewatering bin, geotextile tubes and other
options are also available. FGD wastewater
options include both biological and physical
chemical treatment. The vaporation option
results in zero liquid discharge. Zero valent
iron is an emerging technology.
Presentation:
http://www.mcilvainecompany.com/Decision_Tree/subscriber/Tree/DescriptionTextLinks/Powergen_Scroggin_Presentation.pdf
Recording:
http://home.mcilvainecompany.com/index.php/component/content/article?id=1216
Utility E Alert CCR
Excerpts
– June to October 2019
October 11
EPA has October
2019 Hearing on Proposed Toxic Coal Ash
Rollback
EPA held
a public hearing on its latest proposal to roll
back health and safety standards for coal ash.
A landmark rule in 2015 established the
first-ever federal safety standards for this
waste. But in response to coal industry
lobbying, a new Trump proposal would create
exemptions for two common methods of coal ash
disposal: the creation of uncontained piles of
waste, and the reuse of ash as fill in
construction projects.
There was testimony opposing the roll back. “The
proposed rule changes, which would weaken
requirements for coal ash waste piles and the
use of coal ash in construction projects, fail
to meet the protective standard of RCRA section
4004(a). They are also arbitrary and capricious
and without a rational basis because they ignore
science.
The rule lacks any rational justification for
removing the waste pile safeguards established
in the 2015 coal ash rule. In fact, it directly
contradicts the findings that EPA made when it
developed that rule.
The proposal allows waste piles of substantial
size to remain in place for significant periods
of time without meeting any meaningful control
standards to prevent harmful releases of coal
ash to air, water, and soil. The rule would not
require that waste be removed from the pile
according to any set timetable. As long as the
waste is eventually removed, even if that occurs
years or even decades in the future, the rule
would consider the pile to be “temporary
storage” with no size limits, monitoring
requirements, siting restrictions, or any other
specific enforceable pollution control
requirements.
The proposed rule is also unjustified in failing
to prohibit unlined deposits of coal ash in
inherently dangerous areas. A wealth of
evidence, including monitoring data generated
pursuant to the 2015 rule, indicates that
unlined deposits of ash can leach toxic
substances into groundwater.
Coal ash should not be placed into the
environment at all, but if it is, EPA must adopt
more stringent locational criteria regarding the
placement of coal ash, including distance from
the uppermost aquifer and proximity to unstable
areas, floodplains, and seismic impact zones.
Placement at those sites must be prohibited if
those stringent criteria are not met.”
EPA Coal Ash
Proposal: Unwarranted Mission Creep that will
Harm Recycling
American Coal Ash Association representatives
appearing at a U.S. Environmental
Protection Agency public hearing this
week will testify that the agency's proposal for
revising coal ash regulations will erect
significant barriers to safely recycling coal
ash.
"EPA's proposals related to the definition of
coal ash beneficial use are the opposite of a
regulatory roll-back," said Thomas H. Adams,
ACAA Executive Director. "Without any damage
cases or scientific analysis to justify its
actions, the agency is seeking to impose
burdensome new restrictions that will cause
millions more tons of material to be disposed
rather than be used in ways that safely conserve
natural resources and energy."
"The problem with EPA's beneficial use
definition was that it contained a math error,"
said Adams. "But instead of simply fixing the
math error, EPA is now proposing unjustified and
sweeping changes to the definition that will
have the effect of discouraging recycling. EPA
is proposing to vastly expand the number of
beneficial use activities that must be evaluated
on a project by project basis and the
recordkeeping that must accompany legitimate
recycling activities. People won't do it.
They'll just let the materials go to the
landfill instead."
Georgia Power continues
to make Progress on Ash Pond Closure at Plant
McIntosh with Dewatering Process to begin this
Month
Georgia Power continues
to make progress towards the closure of the ash
pond at Plant McIntosh with the dewatering
process scheduled to begin this month.
Dewatering marks a significant step towards
completing the closure process, and Georgia
Power's ash pond closure plan for Plant McIntosh
is specifically designed for the site to ensure
water quality is protected every step of the
way.
The ash pond at Plant McIntosh will be
completely excavated, with the ash stored in a
permitted, lined landfill on plant property. Ash
pond closures are site-specific and consider
multiple factors, such as pond size, location,
geology and amount of material; and each closure
is certified by a team of independent,
professional engineers.
"As we begin the dewatering process at Plant
McIntosh, we are pleased with the progress we
have made on our ash pond closures at all of our
plants," said Dr. Mark Berry, vice president of
Environmental & Natural Resources for Georgia
Power. "We continue to focus on safety and
meeting all compliance requirements throughout
the process to fulfill our longstanding
commitment to protect the environment and local
communities. We have invested in water treatment
systems to help ensure that our dewatering
process is protective of the Savannah River.
Throughout the process, clear communication to
our customers and the community about our
progress remains a priority."
The ash pond dewatering plan for Plant McIntosh
has been approved by the Georgia Environmental
Protection Division (EPD) and describes
the water treatment system, controls and
monitoring that will be used during the process
to help ensure that the water discharged is
protective of water quality standards. The
planned on-site closure methods are being
permitted and regulated by the EPD.
Communication regarding the closure plan is
provided through EPD permitting notifications as
well as posting on Georgia Power's website.
Georgia Power's ash pond closure plans fully
comply with the federal CCR rule, as well as the
more stringent requirements of Georgia's state
CCR rule. Georgia was one of the first states in
the country to develop its own rule regulating
management and storage of CCR such as coal ash.
The state rule, which goes further than the
federal rule, regulates all ash ponds and CCR
landfills in the state and includes a
comprehensive permitting program through which
the EPD will approve all actions to ensure ash
pond closures are protective of water quality.
Today, more than 75 percent of the coal ash
Georgia Power produces is recycled for various
beneficial uses, such as Portland cement,
concrete and cinder blocks.
TVA plans to
expand Coal Ash Dry Storage Landfill for
Kingston Fossil Plant
The Tennessee Valley Authority is
moving forward with plans to expand the
boundaries of an onsite dry storage landfill
for coal
combustion residuals at
Kingston Fossil Plant near Harriman, Tennessee.
TVA currently operates a permitted
state-of-the-art dry landfill on TVA property at
Kingston for coal ash and gypsum, which is
produced by the air emissions controls at the
plant.
The landfill is designed for two phases, the
first of which has been in operation since 2015.
TVA is proposing to expand the boundary of the
construction support area for the onsite gypsum
landfill by an additional 21 acres to prepare
for the next phase of the landfill. This
additional land would be used as a staging area
for equipment and as a source of clay borrow
material, which will be used in the construction
of a new phase of the landfill.
The Kingston Fossil Plant itself has been in
operation since 1955. Its nine coal-fired units
have a total capacity of about 1,400 MW,
according to the TVA.
In 2008, a dike at the Kingston coal ash pond
collapsed and is considered by some to have
caused the worst coal ash disaster in U.S.
history. Some 1.1 million gallons of coal ash
slurry spilled out into the Emory River and onto
surrounding land, damaging structures.
The TVA spent more than $1 billion on its
Kingston coal ash cleanup.
The TVA has completed an amended supplemental
Environmental Assessment that explains the
expansion of the support area and considered the
potential impacts. The final document and
associated materials are available for review
at www.tva.com/nepa.
TVA already has a construction permit for the
next phase of the landfill. However, TVA has
applied for other required permits through the Tennessee
Department of Environment and Conservation,
which includes a public hearing and comment
period.
August 4
The coal ash dam at Essar Energy’s
1,200 MW Mahan coal-fired power plant in Madhya
Pradesh has collapsed inundating surrounding
agricultural land and damaging the
crops of up to 500 farmers. The Mahan coal-fired
power plant is in Singrauli district which hosts
10 coal-fired power stations with a combined
capacity of 21,000 MW. A local official stated
that “initial investigations reveal that there
was negligence on the part of the power
company.” However, Essar Energy stated in a
media release that the dam failed due to
“sabotage” but did not provide any credible
evidence to support its claim.
B&W New Bottom Ash Conveyor
is Cost-effective approach to meet ELG
Guidelines
The challenge to effectively and reliably meet
regulatory targets for bottom ash handling has
often required plant operators to make
significant investments in equipment
modifications. Babcock & Wilcox (B&W) set out to
develop a new conveyance technology that not
only met effluent limitation guidelines (ELG)
and coal combustion residuals (CCR)
requirements, but also considered unique plant
layouts in providing a simplified and more
cost-effective solution. The result? B&W has
developed, patented and proven
its Allen-Sherman-Hoff® Submerged
Grind Conveyor (SGC) system, which offers
maximized results and minimized modifications to
the existing footprint.
Benefits
• Reuse of existing water-sluice
system’s key components reduces installation
costs for retrofit
• Reuse of existing bottom hoppers
protects conveyor from impact of slag falls
• Capability for redundancy, allowing
for uninterrupted power if one chain conveyor
string is out of service
• Minimized outage time
• Low profile, small footprint
• Improved fuel efficiency and emissions
control from water-filled ash collection hopper
and supported water seal, which is designed to
optimize O2 levels and minimize NOx
• Low-wear, compact mechanical conveyor
system reduces material costs
• Low auxiliary power requirements
• Low maintenance costs
New Water Management
to help TVA deal with Coal Ash Processing
The Tennessee Valley Authority is
touting a newly operational treatment plan to
reduce its land footprint for dealing with coal
ash at its six-decade-old, coal-fired Gallatin
Fossil power plant in Sumner County.
A new water management system for coal
combustion residuals (CCRs) will reduce the
footprint from 435 acres to as few as three,
according to the TVA. The federal energy entity
says the new system is a step forward from
traditional wet ash handling to dry handling and
storage landfill.
TVA implemented the system last month, project
manager Michael Clemmons noted. The flow
management system treats plant process water to
remove contaminants such as grease, oil and
total suspended solids.
“Until now, Gallatin has utilized a 435-acre ash
pond complex to slow treat water compared to the
less than three acres of new water treatment
tanks, which can treat a maximum flow of 43
million gallons a day,” Clemmons added.
Since 2016, Gallatin has stored dry CCR produced
by the Gallatin scrubber in a lined,
state-of-the-art 52-acre landfill, but process
water and bottom ash was still treated in the
ash pond complex. In an effort to move to
completely dry storage, the new flow management
system will treat the water and temporarily
dewater bottom ash (until a permanent dewatering
system comes online later this year), replacing
the need for an ash pond.
“This flow management system fulfills our
commitment at Gallatin to transition from wet to
dry CCR handling and storage, which is cleaner,
safer and more stable,” Clemmons said.
The system complies with the EPA’s CCR Rule and
positions TVA to fulfill the recent agreement
between TVA and the Tennessee Department of
Environment and Conservation to close the ash
pond complex at Gallatin by removal of legacy
CCR.
“I’m proud of our team,” Scott Turnbow, vice
president of civil projects, said. “Meeting our
commitment on CCR is one of the many ways we
serve the people of the valley as good stewards
of the environment.”
Gallatin’s 976 MW of coal-fired units were built
and commissioned in the 1950s. A selective
catalytic reduction system to reduce nitrogen
oxide emissions and scrubbers to reduce sulfur
dioxide emissions were installed on all four
Gallatin units in 2016.
A lawsuit was filed in 2015 alleging bad coal
ash disposal practices at the site. The TVA
settled with the Tennessee Department of
Environment and Conservation earlier this year,
with the utility promising to remove 12 million
cubic yards of CCR.
TVA investing in
many Projects to meet CCR Requirements
Plans have been made for each coal plant with
various alternatives depending on changes in the
regulations. Details on the plans for each plant
are provided.
https://www.tva.com/Environment/Environmental-Stewardship/Environmental-Reviews#coalgas
TVA planning to install FGD
Wastewater Treatment Plant at Cumberland
TVA has
issued a Final EA and FONSI for the proposed
construction of wastewater treatment facilities
at the Cumberland Fossil Plant (CUF). The
treatment is for wet flue gas desulfurization
(WFGD) wastewater.
TVA’s preferred alternative is Alternative 2 –
Construct Wastewater Treatment System, Stages A
& B (described below) and optimize selenium
removal to the extent practical to establish
site-specific selenium and nitrate/nitrite
limits. This alternative would meet the purpose
and need of the project. TVA acknowledges that
Alternative 2 would not likely enable TVA to
meet the limits on selenium and nitrate/nitrate
currently set in the NPDES permit issued for
CUF, which incorporates the limits promulgated
in the 2015 ELG Rule. However, as noted above,
EPA is reconsidering that rule, and TVA’s
application for alternative limits based on
fundamentally different factors is still
pending. To the extent that the reconsidered
rule and/or EPA’s decision on TVA’s
fundamentally different factors application
require more treatment than is contemplated
under Alternative 2, TVA would reconsider its
preferred alternative to enable compliance with
the requirements.
-
Stage A includes installing the
equipment necessary for WFGD
wastewater treatment solids
removal and dewatering. Stage A
is expected to be completed as
soon as September 2020. Gypsum
fines removed during this stage
will go to an on-site landfill.
-
Stage B includes the
physical-chemical wastewater
treatment steps necessary to
remove dissolved and particulate
metals such as arsenic and
mercury from process flows. This
stage represents the expected
minimum treatment requirement
resulting from EPA’s review of
the ELGs. Certain components
could be shared between stages.
For example, clarifiers may be
part of both Stage A and Stage
B.
TVA Plan would close Bull Run Main
Ash Pond with an Interim Cover
In accordance with the National Environmental
Policy Act (NEPA), TVA has
released a Final Supplemental Environmental
Assessment (EA) and Finding of No Significant
Impact (FONSI) for the Bull Run Fossil Plant
(BRF) Ash Impoundment Closure project. The
purpose of the proposed action is to support the
implementation of TVA’s stated goal to
transition from wet to dry storage of CCR at its
coal plants by closing the Main Ash Impoundment
and Stilling Pond at BRF, and to assist TVA in
complying with state and federal requirements
such as the National Pollutant Discharge
Elimination System (NPDES) permit, and the U.S.
Environmental Protection Agency’s (EPA)
CCR Rule. This project would support a long-term
need for wastewater treatment at BRF by
providing a facility for processing non-CCR
wastewater in the near-term and storm water in
the long-term.
TVA’s preferred alternative is Alternative C,
under which the Main Ash Impoundment would be
Closed-in-Place with an interim cover and a
portion (approximately 13 acres) would be
repurposed for use as an interim process water
basin. The Stilling Pond would be
Closed-by-Removal and would also be repurposed
for use as a process water basin. The interim
solution for the Main Ash Impoundment would be
implemented until a decision on a permanent
solution for a disposition of the underlying CCR
is made through the 2015 TDEC Commissioner’s
Order process.
The alternatives presented in the Supplemental
EA are as follows:
-
Alternative A – No Action
-
Alternative B – Closure-in-Place
of a Portion of the Main Ash
Impoundment, Closure-by-Removal
of the Remaining Portion of the
Main Ash Impoundment and
Repurposing into a Process Water
Basin, Closure-by-Removal of the
Stilling Pond and Repurposing
into a Process Water Basin, and
Development of a Process Water
Basin Emergency Spillway
-
Alternative C (Preferred
Alternative) – Interim Cover of
the Main Ash Impoundment and
Repurposing a Portion for an
Interim Process Water Basin,
Closure-by-Removal of the
Stilling Pond and Repurposing
into a Process Water Basin, and
Development of a Process Water
Basin Emergency Spillway
BHE has aggressive Program to
comply with Coal Combustion Residuals (CCR)
requirements
PacifiCorp has
6 active surface impoundments and 4 active
landfills; 3 inactive surface impoundments are
undergoing closure.
MidAmerican Energy operates
2 active surface impoundments and 4 active
landfills. In addition, MidAmerican Energy has 6
inactive surface impoundments; 5 have been
closed, and 1 is continuing closure activities
NV Energy operates
2 active evaporative surface impoundments and 2
active landfills; all other surface impoundments
are undergoing closure by removal.
MidAmerican Energy Company, NV Energy and
PacifiCorp posted the results of their
groundwater detection monitoring on March 1,
2018, in advance of the required posting under
the CCR rule.
-
The ash ponds operated by the
BHE companies are structurally
sound and do not pose a risk to
public safety.
-
The majority of the groundwater
monitoring results are
consistent with naturally
occurring substances, do not
exceed standards for action and
do not threaten drinking water
or human health; however, some
testing results require
additional assessment or action
-
The companies are working with
their states and other agencies
to evaluate the groundwater
results to identify and take
actions that meet or exceed all
applicable requirements and are
consistent with our
environmental respect
principles. This may include
action to close ash ponds and
implement alternative disposal
methods.
Georgia Power continues to Make Progress towards
the Closure of Seven Ash Ponds at Plant Yates
with the Dewatering Process
Dewatering marks a significant step towards
completing the closure process, and Georgia
Power's ash pond closure plan for Plant
Yates is specifically designed for the site to
help ensure water quality is protected every
step of the way.
Four of the ash ponds nearest the river at Plant
Yates are to be completely excavated with the
ash consolidated at the remaining three ponds,
which will be closed in place using advanced
engineering methods and technologies. Ash pond
closures are site-specific and consider multiple
factors, such as pond size, location, geology
and amount of material; and each closure is
certified by a team of independent, professional
engineers.
"As we begin the dewatering process at Plant
Yates, we are pleased with the progress we have
made on our ash pond closure process throughout
the state at all of our plants," said Dr. Mark
Berry, vice president of Environmental & Natural
Resources for Georgia Power. "We continue to
focus on safety and meeting all compliance
requirements throughout the process to fulfill
our longstanding commitment to protect the
environment and local communities. We have
invested in appropriate water treatment systems
to help ensure that our dewatering process is
protective of the area's rivers. Throughout the
process, clear communication to our customers
and the community about our progress remains a
priority."
The ash pond dewatering plan for Plant Yates
that has been approved by the Georgia
Environmental Protection Division (EPD)
identifies the enhanced water treatment system,
controls and monitoring that will be used during
the process to help ensure that the water
discharged is protective of water quality
standards. The planned on-site closure methods
will be permitted and regulated by the EPD.
To date, the company has removed two of the
seven ash ponds at Plant Yates, completed
engineering and feasibility studies and filed
permit applications with the EPD for the
remaining ash ponds on site. Communication
regarding the closure plan is provided through
EPD notifications, advance public notice of
permits and updates to local homeowners and
local media.
Georgia Power first announced its plans to
permanently close all of its ash ponds
in September 2015, with initial plans released
in June 2016. The company is in the process of
completely excavating 19 ash ponds located
adjacent to lakes and rivers with the remaining
10 being closed in place using advanced
engineering methods and closure technologies.
In November 2018, Georgia Power completed the
submission of 29 Coal Combustion Residuals (CCR)
permit applications as required by the Georgia
CCR rule for ash ponds and landfills. These
permit applications outlined significant and
detailed engineering information about Georgia
Power's ash pond closure plans and landfill
operations plans. The permitting application
process was developed and completed with
significant internal and external resources
supported by multiple third-party consulting and
engineering firms.
Georgia Power's ash pond closure plans fully
comply with the federal CCR rule, as well as the
more stringent requirements of Georgia's state
CCR rule. Georgia was one of the first states in
the country to develop its own rule regulating
management and storage of CCR such as coal ash.
The state rule, which goes further than the
federal rule, regulates all ash ponds and
landfills in the state and includes a
comprehensive permitting program through which
the EPD will approve all actions to ensure ash
pond closures are protective of water quality.
In 2016, the company announced that all ash
ponds will stop receiving coal ash in three
years and the significant construction work
necessary to accommodate the dry-handling of ash
is on track to be completed in 2019. Today, more
than 60 percent of the coal ash Georgia Power
produces is recycled for various beneficial
uses, such as Portland cement, concrete and
cinder blocks.
The cost to beneficiate most ores is very
high. The equipment and energy consumption to
convert large lumps into fine particles is
significant. Other steps, such as acid leaching,
require purchase of chemicals and investment in
mixers and other process equipment. Coal-fired
power plant combustion can be viewed as a very
cost-effective beneficiation process. It
delivers very fine particles and the HCl needed
for leaching while at the same time generating
power rather than consuming it.
There is a very good argument to be made that
the power plant should be designed and operated
as a beneficiation process and that power
generation would be the byproduct or only one of
the main products.
With this in mind, the first design requirement
is to select fuels (coal, petroleum coke,
others), which will yield the maximum amount of
product. This would include coals high in
sulfur, chlorine, rare earths, other metals,
and ash with the most value. The second design
requirement is how to most efficiently
beneficiate the ore. It is likely that the
process will be mostly a wet one. The initial
particulate collector (fabric filter or
precipitator) will be eliminated. A series of
two or more rod deck scrubbers will be used for
the primary beneficiation. A tail-end wet
precipitator will meet any particulate emission
standards. Since wet scrubbers can handle low
temperatures and acid mist, the heat exchanger
can be designed to maximize energy recovery from
the flue gases. The end products are power,
pristine flyash, rare earths, other valuable
metals, hydrochloric acid, sulfur, sulfuric acid
or gypsum.
There is no scale-up problem. The process is
already being used in many waste-to-energy
plants in Europe. The essential elements e.g.,
hydrochloric acid and particulate pre-scrubber,
have been proven in decades of operation at a
number of power plants.
This subject is further discussed in
Join
the Debate on Insitu Rare Earth Recovery
Coal Byproducts including Rare Earths will be a
Game Changer
High Chlorine Coals are less costly and can
create a Byproduct
The advantages of using high chlorine coals are
the lower cost and the ability to produce a
byproduct. This article points out that Illinois
coals with 0.2% chlorine content are being
burned in many units without extreme corrosion.
In fact, it is hard to draw a direct correlation
between corrosion and chlorine content. Some
coals with 0.3% coal are being successfully
utilized. The conclusion is that there are
multiple factors creating the corrosion. Steps,
such as more even fuel combustion, can be more
important than chlorine content.
Metso and Outotec Merger creates
a Strong Potential Player in “Coal as an Ore”
Process
The combined company, comprising Metso
Minerals and Outotec but
excluding Metso Flow Control, will
be called Metso Outotec. Combined,
the two had sales in 2018 of about $4.4
billion—and about $4.7 billion when Metso’s
recent acquisition of McCloskey is factored in.
Metso Flow Control, meanwhile, will be a
pure-play listed entity under the name of Neles with
2018 sales of about $668 million.
The combination of Metso and Outotec creates a
major player in minerals and aggregate
processing.
Setting up Neles as a separate company makes
sense from the perspective that while the
measurement equipment will be critical to Metso
Outotec, it can continue to work with Neles but
make it easier for Neles to sell to other
minerals processing companies.
The new CCR rules in the U.S. will create a big
opportunity for the combined company. Metso has
various products to move flyash and bottom ash.
Dry Drag Chain Conveyors: The dry drag chain
conveyor can be applied to precipitators, fabric
filters, boiler hoppers or cyclones for the
collection of fly ash. For dust and fire
control, these units handle fly ash in a
dust-tight, air-tight construction. One
opportunity for the combined company will be
coal flyash.
Submerged Chain Conveyors: Bottom ash is
continually collected, cooled and dewatered with
a submerged chain conveyor. Ash falls constantly
from a boiler through a discharge hopper into a
waterfilled chamber where the continuous-loop,
dual-strand submerged chain conveyor cools it
and transports it for disposal.
Outotec is involved in wastewater treatment and
supply of biomass and waste to energy plants. It
supplies complete plants for the production of
high-quality nickel, from a wide range of nickel
raw materials. Outotec offers innovative and
proven leaching, precipitation, solution
purification, solvent extraction and
electrowinning technologies, as well as
concentrator, sulfuric acid and
pyrometallurgical plants and processes.
Hydrochloric acid regeneration has become a
vital stage in most chloride process flowsheets.
Pyrohydrolysis has been the traditional method
of regenerating hydrochloric acid from a variety
of chloride solutions, including magnesium, iron
and nickel brines.
Outotec has a patent, which demonstrates the
company knowledge needed to extract REES.
The invention relates to a method and apparatus
for recovering metals from metalliferous
starting materials comprising steps of
i. leaching the metalliferous
starting material in chloride-based leaching
liquor,
ii. withdrawing from the
leaching step i) aqueous chloride solution with
dissolved metals,
iii. recovering metal value from
the aqueous chloride solution in a metal
recovery process step,
iv. neutralizing hydrogen
chloride content of the aqueous chloride
solution in the metal recovery process step with
adding hydrolyzed ammonia to the process
solution so as to form ammonium chloride,
v. withdrawing ammonium
chloride containing process solution to an
ammonium regeneration step where
calcium-containing reagent is added to generate
calcium chloride and ammonia gas and recycling
ammonia back to the metal recovery process step
iii),
vi. regenerating the CaCl2-solution
with H2SO4 so as to
provide an aqueous HCl solution for recycling to
the leaching step i).
McIlvaine believes there is a good possibility
that Coal as an Ore processes for power plants
will be very popular. Therefore, this will be a
big potential market for Metso-Outotec
June 28
Beneficial uses of Flyash will
be Continuously Analyzed
Burns & McDonnell says
beneficial use of CCR materials can provide
economic and environmental benefits, as such
uses can reduce costs associated with developing
and operating disposal facilities, provide a
potential revenue source through the sales of
these materials, and reduce the demand for
native raw materials through substitution of CCR
materials. The firm has experience studying or
implementing beneficial use of CCR in the
following areas:
· Underground and surface mine
reclamation
· Coal yard base and pond liner material
(roller compacted concrete)
· Leachate collection system media
· Protective soil cover systems
· General fill material
· Soil stabilization
· Portland cement concrete
· Railroad sub-ballast
The McIlvaine Company will be continuing to
analyze the potential volume and price for each
of these end uses. It will also be looking at
other products such as bricks, which are being
manufactured in the Longking dry scrubber
process.
Another question would be the value of very pure
flyash without any metal, which would result
after rare earth elements (REE) recovery.
Continuous Fly Ash Transfer System
or A2P™ at JEC
The traditional types of pneumatic conveying
systems utilize numerous moving components such
as ash intake valves, swinging or sliding disc
valves, butterfly valves, double dump valves,
and pressure tanks. These systems also require a
moderately sophisticated control system which
necessitates a large amount of discrete
input/output signals. The systems utilize
pressure transmitters, timing devices, and level
switches to monitor/control the conveying
system’s operational sequence. All of these
devices must function reliably and repeatedly
for the system to operate effectively.
FLSmidth Inc. (Airslide®) A2P system
combines two well proven ash handling
technologies. This system stores no ash in the
precipitator’s collection hopper like
traditional ash systems do. As soon as the ash
falls into the collection hoppers, it is
funneled into the Airslide network that slopes
on a slight angle toward an F-K Pump. All of the
hoppers feed the Airslide network continuously
and simultaneously for nonstop ash removal. The
ash residence time from precipitator to storage
silo is only a few seconds.
JEC’s unit 1, 2, & 3 original ash conveying
systems have been exceptionally problematic for
Westar Energy since commercial operation began
in 1978. The three vacuum systems were never
able to remove and transfer the ash from the
precipitator hoppers at a rate that ash was
being produced. This condition worsened when all
of the units increased production and yielded an
increased ash make rate of 27 STPH per unit from
23.4 STPH. High maintenance costs also ensued on
the existing vacuum system, which was
constantly operating at its full capacity. The
total yearly cost to keep the unit 1 fly ash
transfer system operational was nearly $235,000.
The A2P system compared to traditional ash
systems is more advantageous to power plant
operations and encompasses improved design
features, efficiency, and minimal maintenance.
An A2P system will provide a positive return on
investment to the end user throughout its
operating service.
Oklahoma Gas & Electric modifies
Bottom Ash Ponds to meet CCR Requirements
The Red Rock, Oklahoma plant was upgraded in
2015 to meet CCR rules. Burns & McDonnell provided
professional engineering services including
evaluation of existing bottom ash settling
basins for adequate settling of bottom ash
solids as well as structural capacity to meet
the requirements of the Coal Combustion
Residuals (CCR) Rule. The existing bottom ash
settling basins were inadequately sized to limit
solids carry-over. Subsequently, an abandoned
two-cell coal pile settling basin was repurposed
to capture bottom ash solids. Modifications to
the bottom ash water system included structural
upgrades to the repurposed basin, a
jack-and-bore pipe beneath a rail line, overland
and below grade HDPE piping, and multiple
process modifications to the bottom ash water
system. A bottom ash stack-out pad, perimeter
walls, and stormwater drain system were designed
to containerize bottom ash and waste ash solids
for temporary storage.
Air Slide has Advantages in
removing Precipitator Flyash
Westar Energy's
Jeffrey Energy Center converted three
precipitator fly ash handling systems to air
slide style a decade ago. Burns &
McDonnell was the engineer. This was the
first domestic air slide retrofit on a utility
station and has been successfully duplicated at
other power plants since that time.
http://www.flyash.info/2007/42youells.pdf
Replacement Ceramic Rotary Valves
on Limestone Injection saved Money for AC Power
F.L Smidth supplied
ceramic rotary valves to replace high
maintenance valves from a competitor on a
limestone injection system in an AC power
boiler. The supplier’s rotary valves are smaller
than the ones the plant was previously using,
but they can feed more limestone with better
control and no blowback. The new valves provided
a more consistent and reliable feed rate to the
furnace.
https://www.flsmidth.com/en-gb/customer-stories/ac-power-ceramic-feeder-case
South Africa has Program to
utilize Fly Ash
The South African electricity public utility Eskom has
embarked on a process to increase utilization of
the ash produced through the electricity
generation process at its coal-fired power
stations.
In the 2014–2015 financial year, 119.2 million
tons of coal was consumed, producing 34.4
million tons (28.9%) of ash. About 7% of the
Eskom ash is sold from 6 of the 13 coal-fired
power stations. Many stations are currently
running out of ash storage space, and expansion
of the ash disposal facilities is required,
which could affect security of supply because of
limited ashing areas.
Additionally, legislative requirements lead to
extra requirements for ash storage facilities,
requiring high capital expenditure. Increased
utilization of ash will postpone or ultimately
avoid such capital expenditure. The South
African legislative framework strictly governs
ash utilization. For this reason, Eskom has
rejuvenated its Ash Utilization Project.
Ash could play a key role in business
development, job creation, skills transfer, and
localization. The development of small
brick-making facilities in close proximity to
power stations is ideal. It is imperative to
develop new markets that consume high volumes of
ash, including road construction and agriculture
and land rehabilitation. The backfilling of
mines with ash provides an opportunity; tied
collieries are located in close proximity to
power stations and could absorb high volumes of
ash and benefit the ability to rehabilitate
mines and mine closures cost efficiently.
http://www.coalcgp-journal.org/papers/2019/1946-0198-11-1-10.pdf
High Quality Clinker created
with Chinese Flyash
This article summarizes the use of two fly ashes
in the synthesis of Portland/calcium
sulfoaluminate (OPC/CSA or A/CSA) clinkers. They
are from the Shentou second power plant located
in the Shanxi Province and from the Zhungeer
power plant located in Inner Mongolia, China.
The Zhungeer ash was collected dry, and the
Shentou ash is from a pond. Their chemical
compositions differ highly, especially the SiO2
and Al2O3 contents. The high contents of silica
and alumina make both ashes candidates as a
partial or total substitute for bauxite, an
expensive source of alumina, in the production
of OPC/CSA clinkers. These particular hybrid
clinkers are composed mainly of alite (C3S) and
calcium sulfoaluminate (C4A3S), both phases
responsible ´ for the high early strength
development in OPC and CSA cements,
respectively. The production of high-quality
OPC/CSA clinkers was produced with both ashes
with the additions of hydrated lime, flue gas
desulfurization (FGD) gypsum, fluorite, and
bauxite at 1250°C for 60 minutes with final
composition ranges of 29–41 wt% C3S, 20–22 wt%
C2S, 30–45 wt% C4A3S, and 1–4 wt% C4AF.
http://www.coalcgp-journal.org/papers/2019/1946-0198-11-1-59.pdf
SonoAsh separation of Carbon in
Ash creates Value Opportunities
SonoAsh has
developed a sustainable, modular, and patented
solution for production and impounded coal ash.
The technology creates new pathways to make
impounded and production coal ash streams into a
consistent manufactured product designed to meet
regional and individual customer specifications.
Dense Slurry key to ZLD at
Hungarian Power Plant
The U.S. Environmental Protection Agency identified
biological treatment as the baseline treatment
technology for FGD wastewater in the ELGs.
However, it is becoming evident that bioreactors
exhibit high capital and operating costs, occupy
significant space, and are sensitive to changes
in temperature and pH. Dense slurry ash
management can sequester large quantities of FGD
wastewater along with the contained contaminants
through hydration, encapsulation, and
entrainment for a fraction of the cost of
traditional treatment. By using dense slurry
sequestration of FGD wastewater, off-site
discharge of effluent can be avoided altogether.
Dense slurry was employed at (among other
plants) the Matra Power Plant near Budapest,
Hungary, and this technology played a key role
in helping the plant achieve zero liquid
discharge (ZLD). The Matra project is summarized
and data presented that shows how the technology
helped the plant achieve ZLD and other
environmental objectives.
http://www.coalcgp-journal.org/papers/2018/1946-0198-10-1-1.pdf
Putzmeister efficiently moving Dense
Coal Ash Sludge at Largest Brown Coal Plant in
Europe
Alternative forms of fuel are substances, which
have a high calorific value like mechanically
dewatered sewage sludge, tar, paint sludge or
slaughterhouse waste. Putzmeister provides
eco-friendly solutions to waste management and
on-shore drilling that follow a sustainable and
efficient process. It provides modern pumping
systems and technology that cater to the oil and
gas sector, ash disposal process, sludge
incineration systems, cement industry and coal
sludging process.
The Belchatow power station in the Polish
province of Łódź has a capacity of 5,420 MW,
making it Europe’s largest brown coal power
station. The
landfill site for the ash slurry is around 8-km
away from the power station unit itself. The
former system with centrifugal pumps was
overburdened by both the volume and also the
long pumping distance. The wear rate increased
drastically. Failure of the pumps, and hence
removal of the flue ash, would effectively cause
the power station to shut down. The consequences
do not even bear thinking about. The reliability
of the pump system, then, is paramount.
In 2013, a total of six HSP 25150 HP seat valve
pumps featuring the Putzmeister PCF system, each
driven by a 800 kW hydraulic unit, were
installed for transporting the flue ash of the
entire power station. Currently, there are three
pump lines in operation and three on stand-by.
Some 600 m³ of flue ash slurry are pumped every
hour.
Since Putzmeister pumps are capable of conveying
much dryer material, the water consumption is
considerably less. The HSP pumps manage a 1:1
mixture of flue ash and water, relative to
weight. The old centrifugal pumps required a
mixture of 1:10.
Previously, the 420 tons of flue ash
accumulating per hour had to be mixed with 4,200
tons of water. Today, only 10% of this water
quantity is required and so the volume flow rate
is drastically reduced. As a result, the power
consumption is around half as much as that
required for the old pump variant.
GEA has supplied more
than 6,000 MW of Dense Slurry Systems
The very first, then intermittently-operated
Circumix system was installed in 1990 in
Hungary, followed by the first continuous
operation mixer in 1992. The first real
large-scale system was installed in the Mátra
Power Station in 1998 and has been working
trouble-free since. Mátra was also the first
power station where, after a major upgrade in
2000, FGD by-products were also handled by the
Circumix DSS. The first overseas project was
commissioned in 2003 in the Jacksonville North
Side Generating Station, in the USA in Florida.
By 2014, the Circumix systems served over 6,000
MWe coal-fired power plant capacity and have
safely processed and deposited more than 60
million cubic meters of dense slurry
NAES is
the partner in North America. The McIlvaine CCR
Decision Guide includes a presentation by Dale
Timmons of NAES.
India is using Flyash for
Land Reclamation
Many Indian cities are facing a shortage of
land, and land reclamation from the sea can give
great success for these cities. A large quantity
of fly ash has been permitted to reclaim the
land from sea, basically in coastal urban
cities. In 2003, the government of India has
permitted the use of fly ash for reclamation
from the sea. Subject to the rules made under
the Environment Protection Act (1986),
reclamation from the sea shall be a permissible
method of utilization of fly ash. Land
reclamation includes maintaining water and air
quality, erosion and damage to land properties,
minimizing flooding, wildlife and aquatic
habitats caused by surface mining. Singapore and
Dubai have conducted this type of sea
reclamation on a large scale.
Three alternative ways have been investigated to
utilize the waste in sea reclamation projects:
(1) Singapore and Japan‐based technology, (2)
plasma gasification‐based technology and (3)
strengthened sediment‐based land reclamation
technology.
China developing new Flyash uses
as Building Industry Slows
China’s coal-fired power plants produce about
600 million tons of fly ash annually, which has
caused severe economic and environmental
problems. This paper first describes briefly the
production and utilization status of coal fly
ash in China. Then it analyzes the main
challenges to the fly ash utilization in China
due to the conflict between the huge amount of
production of fly ash and the depressed
consumption of fly ash, as well as the
increasing driving forces in environmental
protection. Subsequently, the new developments
of fly ash utilization in China, including
valuable elements extraction, geopolymer
production, fly ash-based ceramics synthesis and
soil desertification control are introduced in
detail.
CFA can mix with cement, gypsum and clay, etc.,
to produce autoclaved aerated concrete blocks.
Because no high temperature is required, this
technique reduces air pollution and decreases
energy consumption. Therefore, the above
utilization ways are very popular in China.
http://www.ijesd.org/vol8/1057-C3001.pdf
High Aluminum and
Iron Flyash can be used to make Flocculants
In this work, aluminum and iron existing in coal
fly ash were extracted by the method of
hydrochloric acid leaching. Effects of
solid-liquid ratio, reaction temperature,
reaction time, acid concentration, and raw ash
mesh on recovery efficiencies of Al2O3 and
Fe2O3 were investigated.
X-ray diffraction analysis indicated that
anhydrite, hematite, mullite and quartz were the
dominant minerals in the raw fly ash sample.
X-ray fluorescence technique was applied to
determine the mass fractions of chemical
components in the raw ash and leached residues,
while the concentrations of Al2O3 and
Fe2O3 in leaching
solutions were measured by titration method. The
optimal recovery efficiencies of Al2O3 and
Fe2O3, obtained under the
reaction condition of 95°C, 5 h, acid
concentration of 20 wt.%, a solid-liquid ratio
of 1:3.5 and raw ash mesh of 400, were 42.75%
and 35.10%, respectively. After removing the
leached residues, the leaching solutions were
employed to manufacture flocculants of polymeric
aluminum ferric chloride for treating the oil
recovery wastewater from polymer flooding, which
possessed high contents of suspended solids (SS)
and oils. Microfiltration membrane and
ultraviolet spectrophotometer were utilized to
determine the contents of SS and oils in water
samples. Through adjusting Al/Fe molar ratio to
20:1 and basicity to 70%, the maximum removing
efficiencies of SS and oils can be achieved,
respectively 96.1% and 91.5%. Moreover,
increasing the iron content and basicity of
flocculants within certain ranges contributed to
improving the settling characteristic of flocs.
https://www.ncbi.nlm.nih.gov/pubmed/29319418
U.S. Utilities facing Major Costs in
meeting CCR Rule
Ameren Missouri will
need to spend between $150 million and $200
million through 2023 on a CCR management
compliance plan, which includes installing dry
ash handling systems, wastewater treatment
facilities and groundwater monitoring equipment.
Vistra Energy Corp.
in February, reported $605 million in "coal ash
and other" noncurrent liabilities as of Dec. 31,
2018. Its power generation subsidiary, Luminant
Generation Co. LLC, operates coal-fired
plants in the Electric Reliability Council Of
Texas, Midcontinent ISO and PJM Interconnection
wholesale power markets and has no end-use
ratepayers from which it can directly recover
costs.
With 66 total CCR units spread across four
states, including landfills, Duke Energy leads
the U.S. in both the number of coal ash storage
sites and total coal ash volume regulated by
federal rule, according to an S&P Global
Market Intelligence analysis. Luminant
Generation ranks second in terms of CCR units,
at 55, and in total volume.
Utilities are facing costs for at least three
decades since 67% are planning to cap the
present ponds rather than excavate the ash.
Coal Ash Plan is
Published – Missouri
Missouri has 36 coal ash ponds, and they vary in
terms of size. Among the smallest is a pond
containing boiler slag at Associated
Electric Cooperative’s Thomas Hill
Energy Center that is 16,000 cubic yards. Ameren
Missouri has some of the largest ponds,
such as Labadie Energy Center’s pond full of
bottom ash, which is 15.8 million cubic yards.
The state’s plan, which became available in
March, would require utility companies to test
groundwater near active coal ash ponds and
landfills twice a year. Companies must test
first for a short list of chemicals that include
boron and sulfate. If there are excessive levels
of contaminants detected on the short list, they
then test for a longer list of chemicals on the
long list, which includes arsenic, lithium and
mercury.
Duke planning to Thermally Beneficiate
Flyash at H.F. Lee Plant
Duke has
applied to install and operate a flyash
processing facility consisting of a Staged
Turbulent Air Reactor (STAR®) with
supporting ancillary sources at the H.F. Lee
Steam Electric Plant. This is one of three
flyash beneficiation projects in North Carolina
(the others are at Duke’s Buck and Cape Fear
plants) mandated by HB 630 (Session Law 2016),
which modified the closure requirements for coal
combustion residuals surface impoundments under
the Coal Ash management Act (CAMA) of 2014. The
law requires the impoundment owner (Duke) to
identify, on or before July 1, 2017, a total of
three impoundment sites (located within the
State) with ash stored in the impoundments on
that date that is suitable for processing for
cementitious purposes. The CAMA requires Duke to
enter into a binding agreement for the
installation and operation of the ash
beneficiation projects capable of annually
processing 300,000 tons of ash each to
specifications appropriate for cementitious
products with all ash processed to be removed
from the impoundment located at the sites. No
later than 24 months after issuance of all
necessary permits, operation of each ash
beneficiation project is to commence.
The facility will process wet or dry flyash
feedstock containing various amounts of unburned
carbon into a variety of commercial applications
including partial cement replacement and other
commercial and industrial applications. The
actual design capacity of the H.F. Lee STAR® facility
is to produce up to 400,000 tons of flyash
product annually.
The STAR® system is a patented
technology developed by the SEFA Group Inc.
(SEFA) to process feedstock (of any carbon
content) like flyash (wet or dry) along with
other ingredient materials into a variety of
commercial products. These products are used,
not only for application as a partial cement
replacement, but for many other commercial and
industrial applications.
STAR Project Equipment Description
The associated sources of air emissions proposed
to support the STAR® system includes
the following:
· Ash
Basin excavation
· Ash
Handling/Processing
· Haul
Roads
· Screener
· Crusher
· Two
diesel engines associated with a Screener and a
Crusher
· Wet
ash receiving area and storage shed
· Wet
ash feed hopper
· Wet
ash unloading pile
· Two
External heat exchangers (EHE) (with baghouses)
· Transfer
silo filling and unloading (with bin vent
product capture device)
· Feed
silo filling and unloading (with bin vent
product capture device)
· Storage
dome filling and unloading (with bin vent
product capture device)
· Loadout
silo (with bin vent product capture device)
· Loadout
silo chute 1A (with bin vent product capture
device)
· FGD
Byproduct Silo (with bin vent product capture
device)
· FGD
Absorbent Silo (with bin vent product capture
device)
Pre-reactor Material Handling Equipment
Excavation and processing of materials from the
ash ponds to meet the STAR® system
flyash ingredient (feedstock) specifications
will be under the control of Duke Energy. All
flyash reclaimed from an ash pond delivered for
use as an ingredient in the STAR® system
Must first undergo processing by the owner to
be:
· Free
of all, but minimal contaminants (e.g., organic
debris, slag)
· Finely-divided
and free-flowing;
· Have a
consistent moisture content below 25%; and
· Have a
consistent chemical composition, including
organic content measured by loss on ignition.
The processing sequence of events will include
flyash being excavated and staged to allow for
dewatering to ensure a moisture content below
25%. Dewatered flyash will then be screened to
remove contaminants (organic debris, slag,
etc.), to produce a consistent chemical
composition and a finely divided free-flowing
material.
Wet flyash with a nominal 15% moisture content
is delivered via trucks. The wet flyash can be
unloaded from the trucks into the storage shed,
to a pile, or directly into the feed hopper at
up to 70 tons per hour then conveyed to the
mechanical conveyance equipment. The material is
discharged from the mechanical conveyance
equipment into a material delumper unit to
reduce large size material. The material is then
discharged from the delumper into the external
heat exchanger EHE by gravity, where it is
continually fluidized using preheated air.
The fluidized material is dried in the EHE both
by intimate contact with the heated fluidizing
air and by direct contact with hot water heat
exchangers located in the EHE. The material is
discharged from the EHE at less than 2% moisture
content and at a temperature range of 150 to
300°F to downstream material-handling equipment
(transfer silos).
The exhaust air is discharged from each EHE
through interconnecting ductwork to a high
efficiency baghouse for feedstock recovery and
exhaust air treatment to achieve a PM exhaust
rate of 0.025 gr/dscf.
After leaving the baghouse, the cleaned exhaust
air stream passes through interconnecting
ductwork to the exhaust air fan before being
discharged to the atmosphere. The exhaust air
volumetric rate is estimated at approximately
41,550 acfm at 10 inches of water column above
atmospheric pressure and at approximately
150-300°F.
STAR® Reactor
STAR® technology transforms and
recycles coal ash from surface impoundments or
ponds into a high-quality, sustainable
environmentally-responsible class F flyash
product for the concrete industry for beneficial
reuse. The process treats flyash in such a way
as to lower the “loss on ignition” (LOI –
residual carbon in flyash) for use as pozzolan
in concrete and can also remove all the carbon
in flyash so that the purified mineral material
can be used as raw feed material in other
specialty products and processes that
historically have been unable to use flyash as
raw feed material because of the deleterious
effect of the residual carbon in flyash. Using
recycled STAR® ash in place of
Portland cement in concrete reduces the virgin
material required in concrete manufacturing, and
for every ton of flyash used in concrete, there
is approximately one less ton of CO2 released
into the atmosphere.
The STAR® process is inherently
flexible in that operating parameters can be
varied, and different ingredients can be added
to produce a desired product. The primary
component of the STAR® is a
cylindrical refractory-lined reactor vessel in
which the majority of the process reactions take
place including both chemical and physical
reactions. Air required for the process
reactions enters through the floor of the STAR® system
as well as through the walls at multiple
locations.
The raw flyash feedstock and any other
ingredients are introduced through the walls of
the STAR®. All of the solids and
gases exit together at the top of the reactor.
Due to the high gas velocity, multiple injection
points, and recycled solids returned, there is a
significant amount of turbulence created that
enhances the mixing of the ingredients and
optimizes the reactions.
The STAR® reactor will normally fire
auxiliary fuels during system startup and will
cut back on auxiliary fuel (i.e., natural gas or
propane) as the reactor reaches auto-ignition
and self-sustaining conditions. At this point,
the residual carbon in the flyash reacts and
becomes the heat source and the process is
normally self-sustaining except under certain
conditions.
The STAR® reactor design capacity is
based on two factors: heat input and flyash
throughput. The reactor’s short-term maximum
heat input capacity is 140 MMBtu/hr. The
reactor’s flyash throughput, however, varies
based on the percent LOI (residual carbon)
content of the flyash, to achieve the 140
MMBtu/hr. maximum design heat input. Duke
expects the LOI to be from 6 to 15 percent.
Based on the heat content of the residual carbon
(14,500 Btu/lb.) the throughput will be limited
to achieve the maximum 140 MMBtu/hr. heat input.
At 6% LOI and 140 MMBtu/hr. heat input the
resulting throughput is 80.5 tons per hour. As
the LOI increases, the throughput decreases in
order to keep the heat input below the maximum
of 140 MMBtu/hr. The reactor system is actually
designed to process 75 tons per hour rather than
the 80.5 tons per hour, which corresponds to a
nominal heat input of 130 MMBtu/hr.
POST-Reactor Material Handling Equipment
After exiting the reactor, the flue gas with
entrained flyash enters a hot cyclone where the
majority of solids are separated from the gas
and recycled back to the reactor for temperature
control. The flue gas with entrained flyash
leaving the hot cyclone is conveyed to an air
preheater, which is designed to preheat the
incoming process air (by heat recovery) or cool
the flue gas/solids mixture, then passes through
a flue gas cooler. The cooled flue gas and
flyash then passes through a baghouse for
product capture, and then exhausts to a dry flue
gas desulfurization (FGD) system (using hydrated
lime as a reagent) to reduce SO2 emissions.
The clean FGD exhaust will then flow to an
induced draft fan to be discharged to the
atmosphere through a stand-along stack. The
captured flyash is pneumatically transferred
from the baghouse to either the storage dome or
the loadout silo, each equipped with a bin vent,
then to a truck loadout station.
Technology –
https://files.nc.gov/ncdeq/Coal%20Ash/documents/Coal%20Ash/air-quality/lee-review-T43.pdf
June 21
India has a Flyash Disposal Problem
India produced about 170 million metric tons of
fly ash in 2017. Hundreds of millions of tons
are presently stored in ponds, which is causing
contamination of ground water.
Over the last twenty years, the image of fly ash
has completely changed from a “hazardous waste”
to “Resource Material.” This is achieved due to
the focused thrust provided by Fly Ash Mission
(FAM) & through Fly Ash Unit (FAU), Department
of Science & Technology (DST) India. Fly ash is
being used in all fields, whether as whole or in
parts. It is being used in the form of cement,
for road reclamation and low-lying areas (RLLA),
road embankments, mine fillings, ash dyke
raising, bricks and tiles, agriculture, concrete
and others. The major portions of fly ash are
being used mainly for civil and construction,
which include cement, mines fillings, concrete,
bricks and tiles, road embankments and
reclamations.
Indian coal has high ash content, about 30-50%,
in comparison to the coal of other countries.
The quantum of fly ash production depends on the
types of coal used and the operating parameters
of the thermal power plants. By the year
2013-14, about 65000 acres of land has already
been occupied by ash ponds. While in the current
year, 2016-17 the annual production of fly ash
in India was about 169.25 MTs and utilization
was 107.10 MTs, and about 63 MTs remained
unutilized. This huge volume of fly ash requires
large areas of land in the form of ash ponds for
dumping which may lead to encroachment on
agricultural land. Such a huge volume possesses
a challenging threat in the form of usage of
land, health and environmental hazards. Other
problems related to fly ash disposal includes
high disposal costs and potential leaching of
toxic heavy metals from the areas of dumped fly
ash into surrounding soil or ground water.
CCR Costs are at least $50 billion over 100
Years for U.S. Power Plants
With the big potential to beneficiate impounded
flyash, the gross cost could be much higher than
$50 billion but byproduct sales could put the
net cost at less than $50 billon
One estimate of costs was provided several years
ago by Sam Yoder, P.E., and Robynn Andracsek,
P.E., Burns & McDonnell (see
McIlvaine recorded interview with Robynn)
Compliance costs are significant for short-term
and long-term. EPA estimated that
the rule would impose 12 regulatory costs: (1)
Groundwater monitoring; (2) bottom liner
installation; (3) leachate collection system
installation and management; (4) fugitive dust
controls; (5) rain and surface water
run-on/run-off controls; (6) disposal unit
location restrictions (including water tables,
floodplains, wetlands, fault areas, seismic
zones, and karst terrain); (7) closure capping
to cover units; (8) post-closure groundwater
monitoring requirements; (9) impoundment
structural integrity requirements; (10)
corrective actions (CCR contaminated groundwater
cleanup); (11) paperwork
reporting/recordkeeping; and (12) impoundment
closures and conversion to dry handling.
According to EPA, the rule may affect 414
coal-fired electric utility plants and
calculates the cost of the rule over a 100 year
period in part because a CCR unit's life spans
40 to 80 years. EPA's estimate of nationwide
compliance is an average annualized cost of
approximately $509 million per year. However,
since these values are for all affected
facilities combined, this is of little
comparison value for understanding the costs at
an individual pond or facility.
One compliance solution is to undergo a wet to
dry conversion for which costs can vary
drastically depending on the footprint available
at each plant ($30 million to $90 million).
Similarly, the closure of a pond can vary
greatly depending on the size and quantity of
CCR material in the pond. Some have seen costs
as high as $80 million to $100 million; however,
most have been in the $30 million to $50 million
range.
Potential corrective actions, such as a pump and
treat system or in situ technology, have
significant unknown and critically important
costs. As utilities are considering future
closure options, the possibility of groundwater
impacts should be taken into account for those
impoundments that will remain active after
October 19, 2015. For these impoundments, clean
closure could be more cost effective in the long
run than a cap-in-place option, which has the
potential for years of corrective action.
Feasibility studies evaluating the potential for
groundwater impacts may be useful at this point
in time for strategic cost savings down the
road.
Given the short time frame for executing
projects associated with the CCR rule, the best
information on compliance costs will only be
available after the fact.
Duke must decide on excavating all its NC Ash
Ponds by August 1
North Carolina officials have ordered Duke
Energy to excavate all its coal ash
storage ponds in the state, saying the utility’s
current plan for its coal ash sites does not
sufficiently protect groundwater. The directive
issued April 1 comes after regulators in other
states, including Virginia, issued similar
rulings regarding coal ash disposal in those
states.
Duke, like other U.S. utilities that have
operated coal-fired power plants, is spending
billions of dollars to clean up its coal ash
storage sites. Managing coal ash, primarily
the handling and disposal of coal combustion
residuals (CCRs), is a major issue for
generators. CCRs are the byproducts produced
from the combustion of coal or the control of
combustion emissions, including fly ash, bottom
ash, and other materials that could contain
mercury, arsenic, and other toxins.
Eight of Duke Energy’s 14 disposal sites in
North Carolina have been scheduled for full
excavation and closure. The order from the
state’s Department of Environmental
Quality (DEQ) says the six remaining
power plant sites, including a total of 11 ash
ponds, must be completely excavated and closed
after what the DEQ said was “rigorous scientific
review” by the agency, along with comments from
neighboring communities. The DEQ, in its order,
said excavation is “the only way to protect
public health and the environment.”
Duke will need to excavate or
cap Ponds at Wabash Energy
Duke Energy will
need to create a corrective action plan for its
coal ash ponds in Indiana after mandatory
groundwater testing found the ponds have
contaminants at levels higher than groundwater
protection standards.
On March 1 Duke released its compliance data and
reporting on the coal ash ponds at the
now shuttered Wabash River Generating Station.
The figures show the ash ponds have high levels
of arsenic, cobalt and lead.
The samples were taken from 37 monitoring wells
placed at the base of the coal ponds, and
weren’t from drinking water wells, said Angeline
Protogere, a spokeswoman for the company.
Duke Energy plans to post its corrective action
plans in July and hold a public forum to review
the plans, she said. “This is a detailed
regulatory process. We will evaluate a range of
cleanup methods and technologies that are
protective of the environment,” Protogere said.
Cleanup options include excavating ponds or
capping the ponds and keeping the ash in place.
Both methods require steps to be taken to
protect the water quality of nearby rivers or
lakes, Protogere said.
We Energies beneficiates Flyash with Reburn System
at Pleasant Prairie
One challenge We Energies faced in
achieving greater percentages of beneficial use
was finding sustainable high volume uses for
coal ash with high unburned carbon levels. Based
mainly on the type of coal burned, the size of
the boilers, and the firing technology employed,
several units within We Energies’ fleet produced
high carbon fly ash and bottom ash, with the
majority of this coal ash getting landfilled.
The high carbon (or %LOI) was viewed as wasted
fuel opportunity, but efforts to improve
combustion on these units were limited to small
gains. With this existing challenge, We Energies
embarked on designing systems at one of its
other power plants that could receive the
high-carbon ash and meter it into the coal
system and boiler with the goal of both
recovering the leftover fuel value and
beneficiating the ash. Ultimately, this
initiative resulted in the installation of both
a dry and wet coal ash reburn system at We
Energies’ Pleasant Prairie Power Plant.
The dry system includes a silo capable of
receiving dry fly ash delivered from other power
plants in pneumatic tankers. This dry, powdered
ash is then metered into distribution pipes and
blown into the boiler burners, where it enters
the furnace with pulverized coal. The wet coal
ash reburn system includes a receiving hopper
and conveyor system for handling wet or
conditioned ash delivered by end dump style
trucks. This coal ash is added to the plant’s
coal prior to delivery to the pulverizers,
burners, and boiler furnace.
https://www.acaa-usa.org/Portals/9/Files/PDFs/ASH02-2015.pdf
NRG loses Lawsuit and
may have to remove Impounded Ash
On June 19, the Illinois Pollution
Control Board (IPCB) agreed with
environmental groups in their lawsuit against Midwest
Generation, LLC, a subsidiary of NRG
Energy, alleging that four of its
coal-fired power plants contaminated groundwater
with harmful chemicals found in coal ash. The
pollution at those four coal-fired power plants,
located in Waukegan, Joliet, Pekin, and Will
County, put the densely populated communities
around the plants at risk. This is a major
victory in a case started in 2012 by the
environmental groups (Sierra Club, Environmental
Law & Policy Center, Prairie
Rivers Network, and Citizens
Against Ruining the Environment).
The IPCB agreed with the groups’ claim that the
contaminants from coal ash at the power plants,
including arsenic, boron, sulfate, and other
chemicals, routinely exceeded water quality
standards and, thus, violated the Illinois
Environmental Protection Act. The groups
alleged that NRG Energy’s subsidiary Midwest
Generation, which has owned or operated the four
power plants since 1999, knew about coal ash
contaminants both in and outside coal ash ponds
and failed to prevent groundwater contamination.
The next step in this case will be a
determination of remedy. The environmental
groups will fight for the most stringent remedy
possible, including a demand for removal of coal
ash dumps at the coal-fired power plants.
Charah Solutions upgrades Unusable Flyash
to a High-Quality Product
MP618 is a thermal process that immediately
reduces loss on ignition (LOI), ammonia,
activated carbon and moisture in fly ash. The
system can be installed at both operating and
non-operating power plants to process current
fly ash production, including dry fly ash stored
in landfills or wet fly ash stored in legacy
ponds, reducing dependence on both.
In addition, MP618 allows for the processing of
kiln dust to remove mercury for emissions
regulations compliance, so the technology can
efficiently deliver a saleable concrete or
cement kiln friendly material from existing fly
ash streams, with no modifications to the power
plant.
Charah claims that MP618 advantages over
competing technologies include:
• Significantly lower cost
profile.
• Efficient footprint with
self-contained environmental controls that can
be deployed in weeks versus years.
• Modular design that can be
scaled up or down to increase production based
on market demand.
• Equipment can be used to
meet demand without requiring high volumes for
cost effectiveness or self-sustaining operation.
• Also enables the
processing of kiln dust to remove mercury for
emissions regulations compliance.
How Big is the Flyash Market?
According to one forecaster, the Asia Pacific
fly ash market is projected to grow at a CAGR of
6.9% during the forecast period to reach USD
2,868.6 million by 2023. The North American fly
ash market is estimated to reach a value of USD
1,065.3 million by 2023, driven by growth in the
regions construction sector in recent years and
high utilization rate of fly ash. Europe is the
world's third-largest fly ash market.
One estimate of the average selling price is
$24/ton is only 4 million tons. Since most
flyash is used for lower value purposes, the
average value may be 1/3 of this price which
would match the 13 million ton annual use in the
U.S., which is estimated.,
The U.S. generates less than 10% of the worlds
flyash. Asia generates 60% soon to reach 70%.
Another article in this Alert shows the amount
of flyash being generated and used in India. It
is very substantial but sold at very low prices
with only a small amount for high value concrete
use.
McIlvaine is preparing detailed country by
country forecasts on flyash and gypsum
production.
UK is importing Ash and
taking Global View
In 2017, the UK generated only one million tons
of ash, recovered 0.5 million from landfills and
imported 254,000 tons. So demand exceeds supply
and this gap will increase with more coal plant
retirements.
From October 2016, the UK Quality Ash
Association (UKQAA) started to accept
members from overseas. As the market for quality
ash continues to grow, UKQAA believes the
importation of ash will have an important role
to play in the future.
While the main role is to protect and maintain
UK production and supply, the transition away
from coal-fired power over the next five years
will have an impact on supply if UKQAA doesn’t
intervene. Importation from around the world has
huge potential and the association believe its
technical advice, guidance, and expertise can
help to safeguard future supplies of quality
ash—a material that continues to enjoy
considerable demand from the construction
industry, and for very good reason.
