1.   AB -32: CO2 Climate Change and the Cement Industry by Michael Stevens of National Cement: • All 6 cement companies and 11 cement plants [...]]]> Here is a list of the speakers for the concurrent Environmental Workshop and our notes on what they had to say during their presentation and during the subsequent Q&A Session for conference participants:

1.   AB -32: CO2 Climate Change and the Cement Industry by Michael Stevens of National Cement:
• All 6 cement companies and 11 cement plants in California are working together to (1) establish a GHG Emissions Cap for 2020 and to (2) establish mandatory reporting rules.
• California’s intent is to be pre-emptive and thereby autonomous.
• Their concerns: (1) the relatively few low-cost abatement technologies that are available and (2) the severe risk of “Emissions Leakage”.
i. “Leakage” means cement imports from other states or parts of the globe who have higher GHG footprints than California able to import cement into California.
ii. It is not protectionism! The Environment is a Global Issue!
iii. The intent is to avoid another OPEC (Oil Producing Export Countries) Effect where a US-based industry moves overseas.
iv. California desires WTO compliance.
v. California would like to establish “sister plants” in provinces in China.
• Their proposal: A Hybrid concept which combines cap-and-trade with performance standards (credits)
i. Where the PCA decides what the “performance standards” are, such as:
1. The use of SCM’s (Supplementary Cementitious Materials).
2. The “re-carbonization” effect of concrete.
ii. Proposed baseline: 1995.
• Cement industry represents 2% of California’s total CO2 emissions.
2.  NESHAP Update by Keith Barnett of the EPA (Office of Air Quality Planning and Standards):
• NESHAP: National Emission Standards for Hazardous Air Pollutants
• The initial standards were written in 1999 (Reconsideration versus Remanded)
• MACT Standards, by law, may be no less stringent than the average emissions from the “best 12 percent” or ‘cleanest’ plants already in operation where data is available.
• In the 2007 Brick Decision, the court found “fundamental failure” by the EPA to set floors (or minimum stringency requirements) at the emission levels actually achieved by the best-performing sources. As a result, the EPA cannot ignore non-technology factors that set HAP limits.
• The March 2007 D.C. Circuit also rejected the EPA’s attempt to ensure that the Brick MACT provided enough leeway to accommodate the operational variability among similar sources (EPA must estimate variability, e.g. wet kilns versus dry kilns).
• Higher emitters are at risk to closure.
• During the establishment of THC Floors by the EPA, only 14 kilns had CEM’s that measure THC so the top 12 percent is only 2 kilns! Based on the fact that THC is so variable based on raw materials found locally, it is easily concluded that there is insufficient data available to set emissions standards.
• Establishment of PM Floors and HCl Floors – Method 321 and Method 5, respectively.
• The proposed rules consider the following pollutants:
i. PM
ii. HCl
iii. THC
iv. Hg
v. HCl
vi. SO2
• Some of the emission-reduction equipment being evaluated includes:
i. broken bag detectors
ii. wet scrubbers
iii. activated carbon injection systems
iv. regenerative thermal oxidizers.
• By 2013, the proposed equipment additions are projected to reduce mercury emissions by 81%-93%, THC emissions by 75%, and Particulate emissions by 90 to 96%.
• The mercury ruling, alone, will affect 93 cement plants and 163 cement kilns in the U.S. The EPA estimates that the capital cost of the program will be about $1.14 billion. However, this is based on 2005 numbers. Today, there are 112 cement manufacturing plants in the U.S. as several new plants have come online in the last four years. The estimated emission control cost for a new 1.2 million-ton-per-year cement line is $17.6 million.
• RTO’s have negative impacts such as increasing CO2 emissions.
• During the Q&A Session, Mr. Barnett seemed to ‘flip-flop’ during the following exchange:
i. In response to concerns about certain plants being unable to survive, Mr. Barnett said, “using the available control technologies, it is possible to meet the limits”.
ii. In response to the EPA’s identification of RTO’s as an “Available Control Technology” when there are only 2 such installations in the US, Mr. Barnett said, “we don’t mandate the use of certain technologies (RTO’s), we only mandate what the emissions limit is”.
• Wet scrubber waste can be used as “gypsum” in the finish mill.
• Activated carbon waste can be recycle and “reactivated”.

3. Mercury Speciation, Evolution and Ultimate Fate in Cement Manufacturing by Connie Senior:
• Mercury emissions can range from less than 1 to more than 1000 micrograms per cubic meter. These are enormous swings! Mercury is difficult to measure in a cement kiln. Stack emissions are 5 to 20 times lower when raw mill is on line.
• There are various measurement methods depending upon the need to distinguish between Hg0, Hg1, Hg2. Distinction between Hg types is important only if you are installing a scrubber because the scrubbers are effective for reducing Oxygenated Hg.
• All measuring methods in flue gas are extractive therefore difficult (for example, the environment is dusty and sampling HgCl2 is very sticky):
i. Impinger methods
ii. Sorbent traps
iii. CEM’s (sampling challenges – variation is great so probably need CEM’s).
• Process affecting Hg in a Cement Kiln:
i. Hg condenses on dust in the FF and onto the feed to a mill.
ii. Typically, 80% can be “scrubbed” by a vertical raw mill.
iii. 50 to 90% can be “scrubbed” across a FF.
iv. If recycling dust, there is no collection. Spikes will occur when CKD is recycled.
• Hg behavior is very complex.
• Temperature control: lowering the temperature of exhaust gas will capture mercury.
• Halogen content can drive change from elemental to oxidized (HgCl2).
• Slip stream dust removal during raw mill running is not an effective control strategy.
• Slip stream to finish mill will reduce Hg emissions during the raw mill down condition, but system removal efficiencies are low so this method may not be effective if significant levels of mercury need to be removed. You need to undertake a complete mass balance of Hg in your system.
• Traditional Mercury Controls:
i. Waste main filter dust (low removal rates)
ii. Wet scrubber (low removal rates and expensive to install & operate)
iii. Activated Carbon Injection
• New Methods for Mercury Controls:
i. Roaster (higher removal rates at lower operating costs due to small system at high concentration rates).
1. Requires heat source (bypass gas, cooler vent, or HGG) to boiling point.
2. Hot EP dust to blending silo.
3. Gas phase Hg then cooled and condenses on Remaining dust. An adsorbent (sorbent) is optional. This Hg-rich dust is then added to finish cement.

4. SNCR & SCR: Their Implication for NOx Reduction in the Cement Industry by Bob Schreiber:
• NOx is 90% NO, 10% NO2.
• SNCR is proven technology:
i. 40% reduction = 400 tons out of 1000 tpy.
ii. Ammonia used as reagent for SNCR.
iii. NSR – normalized stoichiomentric ratio = 1.0 which means assume that it all mixes (no slip).
iv. Reagent cost $669,000 per year.
v. Cost effectiveness in 2008 is about $1,400/ton.
vi. Typically SNCR Systems are able to reduce 30-60% NOx depending upon temperature and turbulence.
vii. Recently being tried in long kilns where the desired temperature range (1850 F) is about 1/3 the way down the kiln.
• There are no successful applications of SCR for NOx reduction in the cement industry:
i. Need to keep the catalyst clean (cleaning system required).
ii. Any amount of SO3 will generate salts which will plug the catalyst.
iii. There is also pressure drop across the catalyst.
iv. SCR requires less reagent than SNCR. However, you need to regenerate the catalyst every 3 years (significant cost).
v. Cannot apply SCR to long wet or long dry because can’t get it at the temperature required … requires gas re-heat on the clean side.
vi. SCR catalyst is poisoned by SO2 (due to higher SO2 to SO3 conversion).
vii. Because of the expense of the catalyst, pilot testing must be performed 18 months in advance.

5. Toxicology of Hexavalent Chromium and Mercury by Rick Pleus:
• Fugitive emissions may be contributing to Hexavalent chrome because heating causes the conversion from Chrome 3 to Chrome 6.
• Trivalent Chromium is needed by the human body.
• Heavalent Chromium (unlike Mercury) is a carcinogen.
• Sources of Mercury:
i. Organic mercury compounds – e.g. fungicides in fish in the form of methyl-mercury.
ii. Inorganic mercury (mercuric) compounds – e.g. medicines and colored paints
iii. Elemental (metallic) mercury – found in thermometers.
• Is the problem global or local? Should there be fish advisories?
i. First, you need to determine the most sensitive endpoints (e.g. babies, elderly, pregnant, and children).
ii. The largest fish have the highest concentration of mercury because Methyl Mercury goes through the food chain.
iii. There are typically higher concentrations of Hg inside the household compared to outside ambient air.
iv. Pregnant women should have fish advisory.
v. Mercury does leave the human body over time.
• Everything is toxic … it all just depends upon the dose!
• The media is often doing a dis-service.
• One nanogram of Cr6 = 1 part per trillion. To put this into perspective, one part per billion is equivalent to just 1 second in 32 years so 1 part per trillion is equivalent to 1/10th of a second in 32 years.
• Don’t pull the fire alarm if there’s no alarm!
• Risk = Outrage + Hazard by Peter Sandman, 2007. Therefore focus on the hazard – not on the outrage!

 Knowledge Transfer

This conference is widely acknowledged to be the world’s leading technical conference for the cement industry and the Cement Industry Committee (CIC) has done some neat things, like the concurrent Environmental Workshop, to make this conference [...]]]> Phil Gaynor shared his thoughts on the purpose of this conference:

 Knowledge Transfer

This conference is widely acknowledged to be the world’s leading technical conference for the cement industry and the Cement Industry Committee (CIC) has done some neat things, like the concurrent Environmental Workshop, to make this conference even better.

I – Integrity (relationships you can trust) M – Mentoring (because in a knowledge-economy, success is determined by the rate you learn) A – Action (communicate common goals and empower [...]]]> Mel Brekhus shared his thoughts on what we, as leaders in the cement industry, need to do in order to thrive in these turbulent and tumultuous times in the cement industry:

I – Integrity (relationships you can trust)
M – Mentoring (because in a knowledge-economy, success is determined by the rate you learn)
A – Action (communicate common goals and empower the community)
G – Grow (because the world is getting smaller, information is getting bigger, so life comes at you faster)
I – Inertia (embrace change – even if it is uncomfortable)
N – Nimble (the most agile survive)
E – Enjoy (have fun doing all of the above)

It’s not so hard to IMAGINE A WORLD IN WHICH CEMENT IS THE FUTURE OF BUILDING PRODUCTS

We hope you can take some time to surf the site and get an idea what BridgeGap Engineering is about.  This site and blog are going ‘live’ at the end of May 2009.  It may take a bit to perfect, but enjoy the [...]]]> BridgeGap Engineering – Where your Cement, Minerals or Aggregate challenge is our opportunity to provide solutions.

We hope you can take some time to surf the site and get an idea what BridgeGap Engineering is about.  This site and blog are going ‘live’ at the end of May 2009.  It may take a bit to perfect, but enjoy the changes as time goes by.

Thanks for investing the time – make a call or send and e-mail.  We’d love to make contact more directly.