APPA Engineering & Operations Technical ConferenceAPPA Engineering & Operations Technical Conference

Presented by: Dale Evely – Southern Company GenerationPresented by: Dale Evely – Southern Company Generation

April 17, 2007April 17, 2007

Preparing for Mercury Preparing for Mercury MonitoringMonitoring

Basic Outline

• Regulatory overview• Impact on Southern Company• Technology review process• RFP process followed• Implementation plans and staffing• Open issues with the technology

Regulatory Overview• EPA’s Clean Air Mercury Rule (CAMR) issued

March 15, 2005• Cap and trade – two phases, 2010 and 2018

– First phase cap set at 38 tons – Second phase cap set at 15 tons

• Mercury monitoring must be in place and certified by January 1, 2009

• Rule left the impression that mercury monitoring technology was already proven

Impact on Southern Company• Approximately 1000 mercury monitors required

across all affected industries in the United States• Approximately 56 Southern Company Generation

(SCGen) stacks require some sort of monitoring• 5 of the 56 are new FGD stacks coming on-line in

2008• 4 new FGD stacks coming on-line in 2009• 6 additional FGD stack systems needed in 2010• At least 49 mercury monitors required in the near

term

Technology Review Process• EPA began evaluations of mercury monitoring

technology using coal combustion test facilities around the year 2000

• EPRI CEM Program began high level evaluations of the technology in the same time frame

• Southern Company followed the issue through EPRI• EPRI report 1004076 in 2002 showed existing

monitors were semi-continuous and needed further development

Technology Review Process• Mid-2004 indications were that EPA was working on

setting mercury monitoring requirements• EPRI setup a supplemental project to work with EPA

on monitor evaluation/development and SCGen signed on to it as a funder

• SCGen decided its own hands-on evaluation would also be required since 61 systems were believed to potentially be needed

• SCGen needed to begin budgeting for the potential monitoring

Initial Budgeting Assumptions (2004)• Able to plug a mercury analyzer into our existing

SOx/NOx racks in our existing shelters• Could slightly modify our existing dilution air clean-

up systems• Existing probes and sample lines would work for Hg• Oxidized to elemental Hg conversion done at

analyzer using dry means• Calibration gas cylinders would be used• Analyzer cost would hold or fall over time

SCGen Monitor Review Process• Had excellent working relationship with our CEMS

integrator since 1992 and a lot of synergies with them

• Began discussions with our integrator to jointly become more familiar with Hg monitoring technology

• Had first of three different monitors (from different manufacturers) up and running at Plant Crist in early 2005; moved to Plant Yates in early 2006

• Two of the monitors were promising• One monitor was a disaster

EPA Monitor Review Process• EPA desired to “prove” the technology• Identified a dry stack in North Carolina and a wet

stack in Kentucky as demonstration sites• EPA allowed EPRI’s contractor to observe and

provide feedback• Difficulties at both sites keeping the monitors running

and Part 75 QA/QC procedures were not attempted• EPA Dry stack work shutdown late 2005• EPA Wet stack work shutdown early 2006

EPRI Monitor Review Process• EPRI took over the Kentucky wet stack site• EPRI desired to work with the manufacturers to

further refine the technology • EPRI also desired to identify issues to EPA that

would impact meeting Part 75 QA/QC requirements• Site has provided great value to the manufacturers

and to the industry and much needed feedback to EPA

• Seven different systems are currently installed at this site and will continue until August

SCGen CMM Procurement Process• SCGen CEMS Task Force began Continuous

Mercury Monitor (CMM) procurement planning in early 2006

• Concerned that only two manufacturers appeared to be close to an acceptable solution

• Questionable that industry need for 1000 monitors could be met by just these two manufacturers

• Decided to “lock” manufacturing and integration capacity to meet our needs

SCGen CMM Procurement Process• Basic schedule that was followed:

– 7/01/06 Begin development of Specification– 8/01/06 Issue RFP– 9/05/06 Begin Bid Evaluation– 9/15/06 Assemble Implementation Team– 9/15/06 Begin refining overall cost estimates– 10/05/06 Purchase Recommendation to Management– 10/31/06 Award Volume Procurement Contract– 4/05/07 Deliver first System

SCGen CMM Specification High Points• Must meet 40CFR75 QA/QC, 40CFR75 certification,

and CAMR monitoring requirements• 90% or better availability on quarterly basis• 90 day or better operation on Hg converters• Relative accuracy that allows annual testing• Easy interface to existing CEMS DAHS• NIST traceable, elemental and oxidized, integrated

and automatic calibration gas generators• Named only two acceptable

manufacturers

• Options for standalone shelters, dual unit shelters, installation at factory in already purchased shelters, installation at site in existing shelters, and more

• CMMS must pass all required certification tests• CMMS software updates and system upgrades to

meet performance specifications included beyond January 2009

• Bulk of deliveries staggered from April 2007 through July 2008

SCGen CMM Specification High Points

Technological Cost Impacts• Probes and sampling systems more complicated and

expensive than SOx/NOx expectation

• Umbilical lines cost about twice SOx/NOx lines• Calibration gas cylinders not viable• Entire rack needed per measurement point• Compressed air need greater than expected• Air clean-up needs increased with volume• Higher Risk = Higher Cost• Craft labor and installation cost increases

CMM System Overview

Sample Transport Umbilical

Calibration Gas Generator

Dilution Probe Controller

Mercury Analyzer

Zero Air Supply

Sample Extraction, Dilution & Conversion

Inertial Probe

Sample Analysis Rack

CMM Budgeting Assumptions (2007)• Average hardware/software cost twice (or more) of

what was originally expected• Average installation cost twice (or more) of what was

originally expected– Some sites require air compressors, platforms, etc.

• Certification testing cost unknown but could be $100,000 each or more

• Annual maintenance cost expected to be $200,000 or more per monitor

CMM Program Implementation• Assembled a multi-discipline, dedicated team

consisting of:– Program Lead Engineer– I&C, Electrical, Mechanical, and Civil Design Leads– Scheduler & 2 Project support engineers– 2 construction liaisons

• Team assisted by:– Retrofit project liaisons– Environmental compliance liaisons

CMM Program Implementation• Standardized approach to ensure:

– Each system uses a standard vendor drawing package– Each system tested at Integrator’s factory– Mounting pad and infrastructure in place before system

arrives at plant site– Installation schedule to support certification testing of all

systems in 2008 following expected SOx/NOx RATA testing schedule

– First system arrives 7 weeks before next system to allow some back fitting of lessons learned

CMM Technology Open Issues• Current SOx/NOx CEMS regularly gives 95%+ data

availability• SCGen and EPRI testing have shown availability

only in the high 50%’s (but improving)• Biggest problems have been probe plugging and

mercury hide-out in the sampling systems• Certification/Accuracy verification is both a

technological and a regulatory issue

CMM Compliance is a 3 legged Stool

Cal

ibra

tion

Rel

iabi

lity

RA

TA

Tes

ting

• Manufacturers have been making great strides on improving reliability issues

• Certification and Accuracy verification issues are in EPA & NIST courts

Accuracy Verification Issues• Calibration gas in cylinders not a good option• Monitored mercury must include total of both

elemental and oxidized mercury • Elemental mercury gas generators proven• Oxidized mercury generators still in development• NIST still investigating all three mechanisms• Once done EPA must issue a NIST traceability

protocol• Systems already being manufactured & installed

Certification Test & RATA Issues• Ontario Hydro Method (OHM) requires great care,

skill and much time• Instrumental Reference Method (IRM) is still in

development and start-up cost may be extreme• Sorbent trap Reference Method (TRM) promised

this year and only real hope for 2008 testing• SCGen has 52 systems to certify in 2008 and 52+

to RATA every year afterwards• OHM would take more than 1 week each

CMM Reliability Open Issues• Mercury hides out in the sampling system• Flue gas (and calibration gas) moisture seems to

minimize this hide out• Selenium and other flue gas constituents tend to

poison the mercury converters• Sampling systems can plug up over time• Ambient temperature at probe can be an issue

CMM Summary• Write a Performance Based Specification• Sign up an Integrator and lock analyzer system and

integration shop capacity• Educate your management that capital and O&M

costs right now are a shot in the dark• Educate your local regulators that EPA is behind• Expect CAMR monitoring requirements to be

revised (DFR) by mid 2007 and respond as needed• Realize you have a lot of company and use your

EPRI investment if you have made one

Industry CMM Status• EPRI CEM business meeting 2/28/2007 with 19

coal utilities represented• 290 CMM systems needed among this group• 142 of these 290 already committed to • Average expectation is one technician needed for

every two monitors for O&M• Sorbent trap based RM being counted upon by

most for certification test purposes

Questions ?