2013 IEEE-IAS PCA highlights

Mercury basics

The ‘Mercury Basics’ tutorial, presented by John Kline and Peter Paone of Bridge Gap Engineering, provided a timely discussion of the issue of mercury emissions.

To put mercury (and other) emissions into political and regulatory context, the US Environmental Protection Agency (EPA) originally said that new, stringent rules, known as NESHAP, would have to be implemented by all US cement plants in September 2013. After a long and heated review period, the EPA modified the rules and pushed the implementation date back two years to September 2015. The US cement industry was pleased by both the rules modifications and the time extension, but also realised that major changes needed to be incorporated in US cement manufacturing over the next two years.

Delegates listened attentively to presentations

concerning nearly every aspect of the cement industry

Mercury emissions were a main focus of NESHAP and the IEEE tutorial walked delegates through the difficulties that lie ahead. American environmental regulators tend to equate coal power and cement production, but the two could not be more different. Producing electricity from coal is relatively simple and straightforward from a mercury emissions standpoint: there is only one input, coal, and it is the source of mercury. Electricity is the only output, though there are byproducts, such as fly ash and FGD. For cement makers, coal is only a source of heat and not the only one given the rise in the use of waste fuels. The ingredients in cement making include limestone and clay, which also can contribute mercury. When it comes to emissions, cement production is far more complex and volatile than running a coal-fired power plant – something that regulators would do well to remember.

Moreover, every cement production line is unique. Both raw materials and fossil fuels can have different mercury levels which vary over time. The cement production process itself is not constant. For mercury emissions, a critical parameter is whether the raw mill is running or not. When the raw mill is turned off, there can be a ‘mercury burst’, a surge in mercury emissions unlike anything that occurs in a coal-fired power plant. There is also the issue of mercury absorption. Many elements in the cement production process may ‘want’ to react with mercury to form other compounds, some toxic and others benign.

In addition, how mercury emissions are measured under NESHAP is an important consideration, whether by spot checks or moving averages. Constant emissions monitoring systems (CEMS) are expensive and time-consuming but are the most comprehensive. CEMS calibration is critical and expensive. Sorbent trap monitoring is easier but less refined. There are also thermal desorption systems, which although simple and quick are not recommended for kilns with online mills. Other methods of measurement include “Ontario Hydro” or EPA Methods 29 or 5B.

Mercury emissions in cement production require extremely fine tolerances and very complex measurement systems. Each kiln line is different. There is no single method that works best for every situation. All mercury containment and measurement systems are expensive, but some are much more so than others, with wet scrubber systems topping the list.

The tutorial pointed out that there are two main ways to control mercury emissions: avoidance and control. You can avoid mercury in the first place through the proper selection of raw materials and fuel sources, but there may be very limited options, economically speaking. Controls run the gamut from relatively simple and inexpensive cement kiln dust (CKD) wasting to costly wet scrubbers and carbon activation methods. In between are low-process temperatures combined with CKD wasting and semi-dry scrubbers.

Kline and Paone stressed that there are no panaceas for limiting mercury emissions from cement kiln lines. Each one needs to be scrupulously analysed to decide what mechanisms will best limit mercury and other emissions.

State of the industry

The conference started bright and early on Tuesday with two presentations on the state of the cement industry. Substituting at the last minute for PCA’s Ed Sullivan, senior economist Dave Zwicke gave the latest PCA forecast. In 2008-09, Sullivan had been in the vanguard of US economists with a highly-negative view of the outlook for the US economy as well as the construction and cement industry. Ironically, even Sullivan was too optimistic about how bad things would get, but he was among the few who came even remotely close to calling the downturn correctly. At the 2012 IEEE conference, Sullivan became much more optimistic about the outlook and Dave Zwicke’s 2013 presentation showed that the PCA economic outlook remained positive with national Portland cement consumption forecast to climb 8.1 per cent in 2013, 8.3 per cent in 2014, and 9.2 per cent in 2015 and 2016. The 2006 peak in cement demand was expected to be matched by 2020 consumption. Historically, 15 years between peaks is a very long interval, but the Great Recession is the worst downturn since the Great Depression and has hit construction and cement demand particularly hard.

Senior PCA economist, Dave Zwicke, provides

US cement demand forecasts for the 2013-16 period

Zwicke stressed that the long recession coupled with continued US population growth had resulted in significant pent-up demand for new housing. Normal population growth implies 1.1m housing starts per year. The Great Recession created a 7m unit shortfall. The PCA was expecting 1.5m housing starts per year by 2016. Positive developments include burgeoning US natural gas supplies and improving American labour markets. On the funding front, MAP-21, which funds federal infrastructure spending, has been extended to 2015, but ARRA (the initial federal stimulus after 2008) is coming to an end.

Worrisome trends were political gridlock in Washington DC, an overhang of distressed homeowners facing potential foreclosure or short sales, and the continuing squeeze on state and local government budgets, which initiate most US public works construction. The PCA also forecasts continuing high fossil fuel prices, which, despite lowering American consumers’ discretionary spending, is positive for the cement industry in competing against asphalt.

Imram Akram of IA Cement Ltd followed with an international perspective. Like Zwicke, Akram’s forecast was positive for the most part, putting 2012 world cement consumption at 3.76bnt with an expected gain of 5.4 per cent in 2013. Akram projected Latin America, Africa, the Middle East and Asia to be the strongest cement markets in 2013 with Brazil, Russia, India and China growing more slowly. The southeast Asian economies are especially strong but western European cement markets remain in decline, particularly Greece, Italy and Spain but also France, Britain and even Germany. Eastern Europe remains weak but 2013 should see modest growth in Romania, Russia and Ukraine. North America is improving, especially Colombia and the USA.

New kiln capacity continues to grow at a historically rapid pace, especially in Africa and the Middle East. On the other hand, most countries now have excess cement capacity compared to current demand levels. These countries are looking to export but the question remains of where to. Another negative are the high debt levels of the world’s major multinational cement companies. There may be ripe opportunities for purchase but the majors are straightjacketed by this debt.

Akram concluded that while world cement prices are rising, operating costs are falling, particularly fossil fuel prices, enabling profit margins to climb. The problem is that world cement capacity is rising faster than demand, making this trend tenuous at best.

After a short coffee break, the technical presentations continued before the conference broke for the day at 17.00h and was followed by an evening reception in the 166-stand exhibition area.

Thinking sustainable concrete

Wednesday began with Cary Cohrs, the current PCA chairman, who stressed the importance of resilient construction – buildings that last a long time without untoward maintenance. The PCA has created a new slogan, “Think Harder. Concrete”, stressing the durability, sustainability and economy of concrete, over asphalt and wood.

The 166-stand exhibition area provided an informal area for networking after conference hours

Professor Kirchain of MIT followed, outlining findings from the industry-sponsored MIT-HUB cement sustainability initiative. The point of most of MIT’s research in this initiative is that taking a comprehensive view of project costs and benefits from beginning to end gives the best indication of societal value, with concrete often turning out to be the best building material to use.

After the coffee break, Al Linero of Florida DOT gave a fascinating talk on ‘The Impact of NESHAP on the Cement Producers of Florida’. His presentation was more empirical, more ‘concrete’ if you will, than most given at IEEE, with plenty of practical information on offer. 

Akin to Tuesday’s format, this day saw a twin set of presentations with those pertaining to climate change, energy efficiency, and environmental regulation generating much interest. Carrie Yongley covered a huge amount of regulatory detail in her talk, ‘The Changing US Regulatory Landscape for Alternative Fuels’. While significant strides have been made by regulators to precisely define the work to be carried out and how best it should be measured under NESHAP and CISWI, uncertainty clearly remains about how cement companies should best proceed to fulfill the new regulations.

Closing banquet and  prize-giving

The closing banquet set the scene for the customary prize-giving. Among the dozens of papers presented at the conference the three top papers of the conference were honoured. Third prize went to ‘Contractor Safety Management’ by John Jerrels and Kendall Walden of Holcim (US) Inc. Second prize went to Rick Bohan of PCA and John Kline for ‘Breakthrough in Clinker Grinding’. First prize went to ‘The Journey of an Enterprise in a Process Industry Toward Improved Electrical Workplace Safety’ by Greg Kemper of Lehigh Hanson Inc as well as Eaton Corps’ Bill Vilcheck and David Durocher.

Following a sumptuous dinner, the attendees walked outdoors to witness a spectacular fireworks display, a daily occurrence for Disney World. Next year’s IEEE Cement Industry Technical Conference will take place in Washington DC. While the nation’s capital is renowned for pyrotechnics, the grandiose atmosphere of Disney World Orlando will be a hard act to follow.