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State legislation will govern the future production of cement

This is the second of two articles looking closely at the cement industry, and Hanson Permanente Cement in particular, as the California Air Resources Board and other agencies begin implementing AB32 greenhouse gas reduction legislation that was passed in 2006.

This article focuses on the future of the cement industry and operations at this plant.

By Cody Kraatz

The future of the cement industry hangs on California's plans to reduce greenhouse gas emissions.

That effort to combat climate change is not likely to produce any drastic changes for the industry, and the new rules that could come down the chute in the coming years are surprisingly simple.

Some of them are already common practice.

"Cement is one of the most greenhouse gas-producing products that mankind makes," said Tom Pyle, a Caltrans concrete specialist.

He heads a state-appointed group that is drafting steps by which the cement industry can help implement AB 32, a state law passed in 2006 to reduce the state's greenhouse gas emissions to 1990 levels by 2020.

California cement plants, including the Hanson Permanente Cement plant and quarry in the hills above Cupertino, are some of the most efficient in the country, so there is little room for improvement there.

Emissions from cement are charting a steady rise, and the emissions intensity per ton of cement--nearly .88 metric tons of greenhouse gases per metric ton of cement--are not likely to drop. Half of it is released from limestone when it's heated in a 2,750-degree kiln.

Fuels are not likely to be changed because alternatives are either too expensive or their use is in its infancy.

"The implementation of AB 32 will largely govern the future direction of Hanson," wrote Tim Matz, Hanson Permanente Cement director of environmental affairs, in an e-mail.

He added that the plant, which is owned by the mammoth German building materials company Heidelberg Cement Group and employs hundreds of workers, is in wait-and-see mode.

But it has become clear that one step is very likely to become a reality through AB 32--: significantly more blending with other materials to reduce cement consumption.

Blending

Caltrans has been replacing 25 percent of the cement it uses with fly ash (ash captured before leaving the flue in a coal-fired power plant) for years.

"The reason we do that is it makes better, stronger and more dense concrete," he said, adding that it has been mandatory as a sustainability effort for about a decade. "What that is doing is...stretching the cement supply."

"It just so happens that it is a very green action...because we're replacing a carbon intensive product with a waste byproduct. Rather than sending it to a dump we're taking a product that has essentially a zero carbon footprint and replacing cement with it."

Experts note that Caltrans increasing use and support of the blends lends credence to their reliability.

The Sunnyvale Town Center redevelopment project and De Anza College's Kirsch Center for Environmental Studies each mixed fly ash in their concrete to be more environmentally friendly.

Blends with fly ash and steel slag (a byproduct of steel production) can take two to four weeks longer to harden, and both products are hard to find in California.

However, even with the emissions from shipping, Pyle said, "it always turns out to be much less than the carbon intensity of the cement itself."

Limestone, another possible blending ingredient, is the primary ingredient in cement itself. Hanson is looking at mixing up to 5 percent limestone, which it quarries in Cupertino, into its cement.

Pyle said that encouraging plants such as Hanson to blend right there at the plant would require minimal operational changes and would distribute blended cement on a much larger scale.

Negotiations

Pyle's cement group made recommendations for a broader AB 32 scoping plan recently. The state plans to release that plan in June.

It is required to be economically and environmentally feasible.

"If the price in California is too high because of AB 32, people will just get it elsewhere." We certainly don't want to create a situation where imported cement [from Asia] is more attractive economically," said Todd Wong, a California Air Resources Board spokesman.

Getting there requires a balancing act, with faces representing cement, concrete, environmentalists, consumers and state agencies at the table.

"To this point they have been very cooperative meetings," said Pyle. "Everybody has been working together to come to a consensus."

Concrete can be green, too

Concrete, it turns out, is not exclusively a climate change problem in the eyes of environmentalists and green builders. It is also a solution.

Concrete's high thermal mass makes it ideal for floors and walls that serve in passive solar systems by gathering sunlight from south-facing walls during the winter and releasing the heat throughout the night, as in the Leadership in Energy and Environmental Design (LEED) Platinum-certified Kirsch building.

During the summer, the concrete is shaded, so it keeps the building as cool as adobes in the Southwest.

Concrete can also be poured to about three inches thick on any floor in a building with tubes for radiant heating inside.

A complex system, such as the one used in two rooms at the Kirsch building, pumps cold water to cool the room and warm water to heat it, radiating the heat in a much more efficient way than traditional forced-air.

Green building experts said that cement needs to be used in these ways in order to be truly sustainable.

Green building experts also said they dream of the day when old concrete can be completely recycled to make new concrete, which would mean no more new cement would be needed.

For now, concrete has one big thing going its way: it lasts a long, long time, hundreds of years if it's treated well.

Emission fee will hit Hanson

The Bay Area Air Quality Management District took the novel step on May 21 of creating a greenhouse gas emissions fee.

It will charge companies 4.4 cents per metric ton of CO2 equivalent they emit. Hanson, the only cement plant in the nine-county district, was number eight in the top 10 Bay Area emitters with 1.06 million metric tons of CO2 equivalent in 2005, according to the BAAQMD.

That would pencil out to roughly $46,627 in fees. Hanson was also the top emitter in Santa Clara County.