Issue Date: June 13, 2011
Coal Evolution In China
The phrase “clean coal” elicits varied responses. To some, it’s a helpful slogan to encourage the use of an abundant raw material. To others, it’s a misleading oxymoron that discounts the environmental impact of a low-efficiency fossil fuel. But as energy demand surges with returning economic growth and concerns about the safety of nuclear power continue, discussions about coal seem to be evolving toward the need to optimize its use because it cannot be dismissed as an energy and feedstock source.
Nowhere is this necessity more apparent than in China, an economic powerhouse that is the world’s second-largest energy consumer but one with minimal petroleum and natural gas reserves. The country has huge coal deposits on which it must depend as it struggles to keep up with its growing energy and feedstock demands.
Coal represents 94% of China’s fossil energy reserves. And at 114.5 billion tons, according to the World Energy Council, those reserves rank third worldwide, behind the U.S. and Russia, and well ahead of China’s oil and natural gas reserves.
At a meeting in Beijing last month—the fifth Defining the Future conference sponsored by the catalyst company Süd-Chemie—catalyst and process technology experts joined potential customers to discuss future opportunities from China’s use of its coal for energy and feedstocks.
“There is plenty of coal available,” asserted Süd-Chemie Chairman Günter von Au as he opened the biennial conference, “and it will play a key role in power and chemical industries, especially in China.” The record crowd of largely local attendees concurred.
“China is a key market for coal-based technologies,” noted Ulf Herrlett, vice president of engineering and technology at Lurgi, the engineering and construction division of Air Liquide. In his keynote address, Herrlett referred to the region as an “open-air lab for coal utilization,” where technology suppliers and operators continue to develop and optimize coal-based operations. He highlighted China’s difficult balance between its needs for secure energy and chemical feedstocks to ensure continued growth and increasing concerns about their environmental impact.
Indeed, the environment features prominently in China’s 12th five-year plan, which covers the country’s economic and social goals for the period from 2011 to 2015. The government plans to boost funding for energy-saving activities and has set ambitious targets for energy efficiency and reduction of greenhouse gas emissions (C&EN, March 14, page 10).
Cao Xianghong, a senior consultant at Sinopec, China’s leading oil and petrochemical company, acknowledged the tension between energy security and environmental protection in his review of petrochemical development in China. “Petrochemical production from coal should be rationally developed, due to its water consumption and CO2 emissions,” he noted. At the same time, Xianghong encouraged continuing development of coal technologies to maintain energy and feedstock diversity.
Creating energy from coal emits roughly 75% more CO2 than from natural gas and about 25% more than from oil, according to an analysis by Dennis Silverman, a physics professor at the University of California, Irvine.
Several coal-based chemical processes have been introduced in China in the past few years, reported Lei Xia, managing director at Asiachem Consulting. As part of the economic stimulus package put in place after the 2008 financial crisis, the Chinese government encouraged demonstration units for five coal-based processes: coal to liquids, coal to olefins, coal to ethylene glycol, coal to synthetic natural gas, and coal to dimethyl ether. Nine units based on these processes are operating throughout the country currently, Xia reported, and four synthetic natural gas projects—the first for this process in China—were approved in 2010 and are under construction. Asiachem expects double-digit growth for all of these technologies except dimethyl ether, which remains a tiny fuel market with uncertain demand.
Many companies are competing to provide process technology, catalysts, and engineering capability for these new units, with a focus on energy-efficient use of coal. Much of the technology comes from companies based in Europe and the U.S., but several Chinese firms have also developed capabilities in coal chemistry, Xia added.
China is a critical market for Süd-Chemie’s catalyst business. The company produces catalysts for the purification of gas streams from coal-conversion units and for the production of chemicals from coal-derived natural gas and synthesis gas. It has more than 1,000 staff in the country and local catalyst production that it acquired in 2009. The firm’s Catalysts Division leader, Hans-Joachim Müller, emphasized the importance of catalysts in improving energy and resource efficiency. Speaking broadly, he assured the audience that “catalysts will be a major theme for the 21st century.”
Manoj Nagvekar, technology manager at Texas-based engineering company KBR, discussed a proprietary technology that boosts the energy utilization of low-quality coal. Known in the market as TRIG, for transport integrated gasification, this coal gasification process produces synthesis gas as a first step for power generation or chemical and fuel production. The first commercial-scale application of TRIG, in power generation, will begin operation later this year at Dongguan Tianming Electric Power, in Guangdong province. A similar U.S.-based unit is planned for Kemper County, Miss., by 2014.
The technology will also be used by Xilinguole Sunite Alkali Industry Co., in Inner Mongolia, to produce synthesis gas for ethylene glycol production. Operations are expected to begin in 2012.
The focus on low-quality coal is important, according to Clyde Payn, chief executive officer at Catalyst Group, a U.S. consulting firm. “An unusual challenge for China is that much of its coal is subquality,” he said. Local coal has high sulfur and ash content, which makes processing and efficient energy extraction particularly challenging.
Switzerland-based engineering firm Foster Wheeler introduced a new technology to address the purity challenge of poor coal streams. Its Vesta technology produces natural gas from coal-based gasification streams at moderate temperatures and minimal sensitivity to sulfur contamination, according to the firm’s process and technology director, Luigi Bressan. He also stated that the technology facilitates the removal of CO2 if operators plan to capture those emissions.
The process expertise of Lurgi is focused further downstream on synthesis gas purification, methanol production, and conversion of methanol to propylene and dimethyl ether. The company installed its first methanol-to-propylene unit last fall in Ningdong for coal producer Shenhua Ningxia. The plant is coupled with a 1.1 billion-lb-per-year polypropylene unit that started up this spring. Such on-purpose propylene production is becoming increasingly important as ethylene production around the globe shifts to cheaper, lighter feeds that generate less coproduct propylene.
And Asia needs propylene, noted Chemical Market Associates Inc. Director John Bonarius. His consulting firm forecasts that the region will consume half of the world’s propylene supply by 2015. In addition to the Shenhua unit, CMAI lists nine coal-based methanol-to-olefins plants that are expected to open through 2016.
It is the lure of such large opportunities that keeps Western companies thoroughly engaged, Lurgi’s Herrlett says, noting that “the technology supply competition will be fierce.”
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