Shougang trials waste plastic in coke-making at Tangshan

In addition to looking at their own emissions, steelmakers have some opportunities to help reduce the environmental impact of other materials. The use of plastic, both as a source of carbon units and for the physical properties it can give to coke, could be one way of doing this profitably.

SBB 9 June A subsidiary of north China steel giant Shougang Group named Shouhuan Technique, based in Hebei province’s Tangshan, has begun introducing waste plastic in its coking operations aiming to supplement coking coal and help cut production costs.

Trials using a pilot plant began in May and Shouhuan Technique hopes to use about 10,000 tonnes/year of soft plastic waste such as sheeting and bags for blending with low-caking coking coal. These are then carbonised to produce coke.

A Shougang researcher tells Steel Business Briefing that its method differs from that of say, the Japanese mills, where used PET bottles are granulized first before being used in the coke ovens. Shougang directly blends soft waste plastic with low-caking coking coal before sending the result to a reaction chamber.

“The key step in the process is to perfectly control the temperature to ensure the waste plastic melts rather than burns so that it enhances the caking ability of the (weak) coking coals,” he says. Indeed, results to date show the ‘molded coal’ obtained through the process produces coke of sufficient quality for use in Shougang’s 4,000 cubic m blast furnace in Tangshan.

“However, the (pilot) plant’s scale is small and we need to wait to see how successful the process is for reducing costs,” says the researcher. “But I believe it will perform well, as the price of waste plastic is much lower than premier coking coal.”

Products of Shouhuan Technique will be fed to Qian’an Zhonghua, a jv between Shougang and Kailuan Coke Ltd that supplies coke to the steelmaker’s works. The jv’s present coke-making capacity is 3.3m t/y. For now, plastics will meet only a tiny fraction of Shougang’s carbon units.

Beijing extends ban on coke plant expansions

Although China’s central government has committed to reducing the energy intensity of its economy, it has found it difficult to pursue this policy. The reach of central government does not always extend as far as individual companies. Small companies regularly flaunt central government decrees and regulations. Meanwhile, the ‘invisible hand of the market’ may be see-through because of its absence. Even when profits are hit, companies continue to invest in an overcrowded and polluted market.

SBB 14 April China’s central government has extended its 2009 ban on coke expansion projects to an unknown future date to meet its energy targets Steel Business Briefing learns.

In late September 2009, Beijing banned expansion projects until 2012 to reduce overcapacity and reduce pollution. However, the policy was not properly enforced by local governments, a central government notice states. Beijing is trying to reduce China’s carbon emissions by 40-45% by 2020.

An industry analyst in Shanxi, the country’s largest coke-producing region, tells SBB he assumes the ban will be extended for another three to five years. “China is facing heavy pressure on carbon emissions [from the international community], so it is unlikely for government to cancel the ban.”

However, SBB notes that there are still many upgrade coke projects on-going. “The coke industry doesn’t run well, but sometimes the coke plants can still earn money, and private coking coal mines will likely to build their own coke ovens [without applying for loans],” says the Shanxi analyst, “And if they don’t need loans the central government’s order will be ineffective.”

“Even if no new capacity is coming on stream, the existing capacity is already too large,” a Shanxi-based coke producer tells SBB. She adds that she holds a pessimistic outlook of China’s coke industry in the future. As SBB has reported, Shanxi’s coke industry saw small profit margins in 2010 caused by overcapacity.

Firm aims to debut carbonite as greener fuel

Even in the USA, where greenhouse gas regulation is less strict than in Europe, there are commercial advantages to developing greener products.

SBB 29 March A US company known as Carbonite Corp will construct a $20m plant this year that will produce carbonite and coke near Norton, Virginia, Steel Business Briefing understands.

According to process pioneer Richard Wolfe, carbonite – an interim step between coal and coke – is cleaner to produce.

“It’s certainly going to be more environmentally acceptable to build this plant,” Wolfe said. “And the products will be more environmentally clean.”

From a regulatory standpoint, the plant would be classified as a coal conversion plant, rather than a coke oven battery, and therefore easier to permit, Wolfe said.

The plant’s capacity will be 50,000 short tons annually, Wolfe told SBB, with some of its products for use in foundry applications and others in steelmaking.

According to US government data and the American Coke and Coal Chemicals Institute, 16.1m s.t of coke were produced domestically last year, the vast majority of which was used for steelmaking. Just over 1.1m s.t of coke were imported in 2010.