BridgeGap Engineering Blog » cement production

Cement Demand to Increase with Rebuilding of Infrastructure

Hannah — Thu, 16 Jun 2011 22:06:41 +0000

With America’s infrastructure crumbling and the economy still struggling to recover from its nosedive, a game of passing the buck has begun. The federal government has no money to foot the enormous bill of rebuilding and expanding roads, bridges, water and waste treatments systems, etc. Just recently a group of senators has drafted a bill that will give about $56 billion a year towards highway and transit construction. While this is a step in the right direction, America’s infrastructure needs hundreds, not tens of billions of dollars of work. Thus, much of the responsibility of finding funding is passed off to the state government. These men, in turn, look at the trillions of dollars of debt they face, and pass the responsibility on to more local governing bodies. Where will it stop? At some point it must. Indeed, maintaining and rebuilding the country’s infrastructure is necessary for the operation and safety of society, much less for America to keep up in the global race of technology and expansion. Given that America cannot ignore the state of its infrastructure, what does this mean for cement companies who produce one of the primary materials needed for this massive renovation project? Whether America attacks the problem – beginning with the passing of this new bill – or waits until the last minute in each situation, there will be an enormous need for quality cement. It may come as a slow but steady need, or in the form of mass contracts – only time and the government will tell.

“Painful Adjustment” in NA and Europe

Demosthenes — Wed, 30 Dec 2009 18:50:37 +0000

The Financial Times reports today that the major cement manufacturers expect cement demand in Europe and The US to be 30% and 44% (respectively) lower than in 2007. A squeeze on infrastructure projects, thanks to exploding government debts and tightening of spending is primarily to blame, they said.

The major producers are clearly focused on developing markets where demand is more organically and necessity driven. They don’t expect the situation to turn in the developed markets until 2012. Even so, given the time to market for a new production line and the spectre of impending CO2 regulations and their potential impact on capacity, we believe that regions in North America can expect to see cement shortages and high prices in the coming years as a result of the major producers business focus being elsewhere.

This is one of the consequences of the industry consolidation that has taken place over the last decade and a half. As the local independent producers have been absorbed by the global producers, the business focus has shifted from one of defining and fulfilling local market needs to one of looking at complete continents as a single market. This is not necessarily good or bad, it just is. The global producers will be investing their available capital in markets they see as having the largest short term potential. The result is that near term opportunities may be created in the Americas and Europe for those who are willing to take a risk and gain first mover advantage. Demand will continue to grow in these markets, and in some cases that demand might be extremely localized.

Concrete Science

Demosthenes — Wed, 16 Sep 2009 23:40:17 +0000

Researchers at MIT have discovered something that has eluded science for all of history. In research funded by Portuguese cement producer Cimpor, MIT has finally modeled the crystalline structure of cement hydrate. Yes, in spite of cement being the most widely used manmade building material in the world, no one really knew how it worked, at least not on a molecular level!

What does such a discovery mean? In some ways it can be compared to the unravelling of the human genome. The potential applications of the knowledge are widespread. For starters, understanding the structure of cement will make it easier to find ways to modify its properties. Inevitably it will also ease the path to methods of production with lower energy consumption and emissions.

MIT doesn’t claim to have completely defined the structure, they call their model a “first step toward a consistent model of the molecular structure of cement hydrate”. Clearly work remains to be done, but there is no doubt that this knowledge will ultimately change the industry.

Pixie Dust Redux

Demosthenes — Tue, 15 Sep 2009 00:21:58 +0000

Calera is back in the news with it’s CO2 eating cement made by reacting stack emissions with a magnesium salt rich water solution. The San Francisco Chronical is reporting on his pilot plant and California and the fact that Constantz has managed to get himself invited to speak about Calera to the World of Concrete trade show in Las Vegas next February. They quote a spokesman from The Sierra Club declaring the technology “a game changer”.

We wrote about Calera before in our “Magic Pixie Dust” post, a term taken from one of the critics of the technology. At BGE we don’t know if Calera is engaging in science, magic or fraud but we do know this kind of publicity and attention is “game changing” at the end of the day.

This is mainstream press in a large, environmentally sensitive market. Whatever it is that Calera is producing, game changing or not, you can bet the political pressure will be turned up to legitimize it. Further, every article about Calera “educates” the public further about the CO2 costs of cement, and turns up the heat on the government to mandate cleaner production.

Cement is certainly one of the most important building materials in the world and is critical to continued economic development, however cement is going to have a CO2 image problem in a hurry. The green benefits of concrete construction need to be better understood by the public and better articulated by the industry.In addition, the industry has to show that it is genuinely interested in investing in technology that will reduce or sequester CO2 emissions, and that it is not content to wait until it is regulated to do so.

Technology is available today to reduce plant emissions, without resorting to magic. BGE can help every producers find the right technologies to apply to their facilities to make a real difference.

How Important is Time in the 21st Century & How Do You Manage It?

experts@bridgegap — Sun, 07 Jun 2009 02:30:39 +0000

How will Business in the 21st Century Look? Sure it depends on your industry… but the value of time… how can you measure it?

Check out this link - Sony played this mind-blowing video at their Executive conference this year

Mind-Blowing Video… time in the 21st century

In the 21st Century where knowledge is relatively cheap, time is nearly priceless and experience can be difficult to find… how do you most effectively structure any business? It seems to the experts at BridgeGap Engineering that relationships you can trust for timely responses and results are of key importance. The value of time will continue to increase as change happens faster.

Economic Recovery?

admin — Sat, 06 Jun 2009 06:53:10 +0000

Notwithstanding the excellent speech by Ed Sullivan at the IEEE Conference we reported on, the Washington Post today reports that job losses slowed dramatically in May, and were far smaller than analysts predictions, fueling hopes that economic recovery is near. While the hoped for bottom in housing has yet to be seen, more promising signs seem to be reported every week. Is all this just the result of deficit spending driven stimulus or is the turnaround real?

IEEE Conference Environmental Workshop

experts@bridgegap — Sat, 06 Jun 2009 00:39:30 +0000

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!

Conference Attendance

experts@bridgegap — Sun, 31 May 2009 16:45:16 +0000

Conference Organizers are pretty satisfied with the level of attendance (600 people are reportedly registered) in consideration of the weakened economy. Even more satisfying is that 80 of the 600 are cement producers. California Portland and TXI are key contributors to attendance. Ash Grove has only one registrant, but reportedly will be back in 2010 to support the conference in a big way as long as economic conditions do not worsen. Lehigh-Hanson has one registrant. Titan America has one registrant. Holcim has zero registrants. Holcim is currently in “start-up” mode for the world’s largest cement plant (12,000 tpd) which is the 2011host plant. The sites for future year’s are as follows:

2010 – Colorado Springs – GCC – Pueblo – March 27-31, 2010
2011 – St. Louis – Holcim – Ste. Genevieve – May 22-26, 2011
2012 – San Antonio – Cemex – Balcones – May 13-17, 2012
2013 – Orlando – American Cement
2014 – Calgary/Banff – Lafarge – Exshaw

UPDATE: Get ‘play-by-play’ of the 2009 IEEE/PCA Conference in Palm Springs California

experts@bridgegap — Sun, 31 May 2009 13:00:25 +0000

Update : This site and blog are going ‘live’ on Sunday May 31st, from the 2009 IEEE/PCA Cement Industry Technical Conference in Palm Springs, California USA. As a courtesy to our customers, we will be posting live updates during the conference to give you a “play-by-play” feel to those of you who could not be in attendance this year due to the weakened economy. So, check this blog early and often!

Welcome to BridgeGap Engineering

experts@bridgegap — Sat, 30 May 2009 17:33:55 +0000

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.