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When Light is Dark: Waste from Key Solar Cell Ingredient Damages Chinese Environment

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China is courting environmental disaster in its rush to industrialize, but China is also known to be addressing some of its environmental problems.  Which is winning, industrialization or the environment?  Here I offer several examples that contrast Chinese and Western environmental practices, including recent revelations from The Washington Post about the Chinese industrial plants that supply polycrystalline silicon for solar panels.

First, some personal anecdotes: I once worked with several industry insiders who had visited a Chinese chemical plant. The story they told was that that local plant manager acted like a Warlord, complete with bodyguards and a local police force that appeared to be a private army; it was clearly dangerous for local villagers to protest any suspected toxic waste dumping or other activities by the plant, and jail, or worse, might be the consequence.  The visit was, in many ways, a disturbing experience for the Western scientists and engineers.

More recent stories, including some on my environmental blog, Chemistry for a sustainable world, have continued to add to concerns about China's environmental practices, even though there are signs that, at least in some cases, official or corporate protection of the environment is improving in China.  As a sign of growing awareness, but not effective action, I was also told during a recent interview with Chinese author Qiu Xiaolong that certain restaurants in China are now claiming to soak live fish and sea food in "clean water" for several days to wash out toxic chemicals. This is not a technique that I would expect to be very successful, even if it does indicated increased awareness.  The title of this article is a reference to Qiu Xiaolong's great novel about corruption in China, When Red is Black

Now, we have new information from reporter Ariana Eunjung Cha of the Washington Post, who published the March 9th, 2008 story “Solar Energy Firms Leave Waste Behind in China”. From this story, we learn about the Chinese response to the world's hunger for polysilicon, short for polycrystalline silicon, a material used to make most solar panels in use today.  According the Washington Post’s article, this demand for polysilicon has caused its price to increase by more than a factor of ten in the past five years, and the rush to meet market demands has led to many new polysilicon plants being built in China. Such plants include the Luoyang Zhonggui High-Technology Company’s facility “located in the central plains of Henan Province near the Yellow River,” a major subject of Ms. Cha’s article.  The article explains that, in addition to supplying the growing worldwide need for solar panels, these new polysilicon plants have created serious environmental problems, mainly for poor Chinese villagers who live in the rural areas where Chinese chemical plants spring up. These plants are typically located outside normal tourist routes, and operate outside the law, or the stated laws and policies of the Chinese National Government.

The main, specific environmental problem with polysilicon manufacture is the byproduct SiCl4 (silicon tetrachloride), which can be processed and recycled safely, albeit at very high temperatures, as is done in the West.*   When simply dumped in the countryside, however, the liquid silicon tetrachloride releases highly-toxic and corrosive hydrochloric acid (HCl) and also generates a fine powder of silicon dioxide, the same material that sand is composed of, though the fine nature of the powder allows in to be readily inhaled or ingested.  The production of HCl occurs when silicon tetrachloride reacts with water in the soil, eyes, mucous membranes, etc., and with moisture in the air.

Since villagers near the Luoyang Zhonggui plant had described blatant dumping by trucks from the plant, the Washington Post arranged for chemical analysis of dirt taken from the dump site.  “The tests showed high concentrations of chlorine and hydrochloric acid, which can result from the breakdown of silicon tetrachloride and do not exist naturally in soil.”

Even though initial capital costs of silicon tetrachloride recycling facilities are high, and the operating costs are also high (because of the elevated temperatures required), it would be wrong to think that the money isn't available in China to implement this waste processing, it is simply a question of priorities. In fact, some Chinese are becoming extraordinarily wealthy from polysilicon companies, and Louyang Zhonggui, as reported by Ms. Cha, “is a key supplier to Suntech Power Holdings, a solar panel company whose founder Shi Zhengrong recently topped the list of the richest people in China.”

However, when faced with questions about environmental practices, the arrogance displayed by Luoyang Zhonggui company officials will unfortunately be all too familiar to those who follow civil rights or environmentalism in China.  This attitude will be just as familiar to those who have followed the continuing struggle to introduce environmental controls to the United States over the past 50 years.  As reported by Ms. Cha, “Wang Hailong, secretary of the board of directors for Luoyang Zhonggui, said it is "impossible" to think that the company would dump large amounts of waste into a residential area.  "Some of the villagers did not tell the truth," he said.”

Apparently even the impossible is commonplace in China. Ms. Cha and the Washington Post are to be congratulated for their investigative field work.

The blatant disregard for human safety and environmental health exhibited by Luoyang Zhonggui is not unique to China. However, a Chinese expert is quoted by Ms. Cha as follows, "If this happened in the United States, you'd probably be arrested."  In the U. S. A., we've seen similar disregard for the consequences from many sources over the years, including mining companies and various energy and chemical producers. In Europe, similar problems with the environment are well documented. However, the U. S. Environmental Protection Agency (US EPA), the European Union, and growing public awareness (dating back to publication of Rachel Carson's Silent Spring) have eliminated, remediated and prevented many environmental problems (even if there are still areas that badly need intervention, or simply need the government to enforce its own laws and regulations).

So, should China be allowed to poison its own people and land for the sake of Capitalism, the way other countries did during the rise of industrialization?  If you think that this is an overstatement, please read the rest of Ms. Cha's article.  The outside world has little influence over internal affairs in China, but we should use what influence we do have: while developed nations still have much work to do in environmental areas, and must remain vigilant against backsliding, it is a tragedy for the Chinese people that their country is unwilling to learn much from the mistakes, including serious disasters, of more-industrialized nations.

In the meantime, there is new solar panel technology that doesn't require polysilicon, for example, "solar paint" developed by Nanosolar and “solar ink” recently described by Konarka. Nanosolar’s solar technology is reportedly more efficient than coal at generating electricity.  We can hope that these new technologies will continue to make inroads into the marketplace and will drive the construction of greener manufacturing facilities.  Given the growing demand for green electricity from solar power, such advances can’t come soon enough.

*See this link for a PDF file on Lifecycle Assessment of Crystalline Photovoltaics by Niels Jungbluth (note this links to a PDF!); for more background on polysilicon fabrication and related processes, see The Handbook of Silicon Semiconductor Technology, W. C. O’Mara, R. B. Herring, L. P Hunt eds., Pub.: William Andrew, Inc. (Noyes Data Corporation/Noyes Publications), 1990, 795pp, Chapter 2, “Polysilicon Preparation” by L. C. Rogers, p 33ff.  Also see Wacker Polysilicon, the History of the Future, available as a 13-page PDF or as a (less readable) web page.

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