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Fuelling the future (part two)

Clean-coal technology and improved fuel efficiency are crucial to China. In the second part of an interview with chinadialogue, Ni Weidou urges development of integrated systems with a range of benefits.

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chinadialogue: In China, coal is the dominant energy source and the majority of this coal is used directly for burning. What serious environmental problems are caused by burning coal?

Weidou Ni: The distinguishing characteristics of China’s natural energy resources are abundant coal, scarce oil and a little gas, so in terms of primary energy production and consumption, coal has always held a dominant position. In 2005, China’s standard coal consumption reached 2.22 billion tonnes, standing at almost 70% of total energy consumption. In the use of this coal, 80% is directly for burning. Coal burned by coal-fired power plants accounts for over 50% of this. Over 70% of power plants on China’s electricity grid are coal-fired, while hydro, nuclear and other sources of power for electricity production account for no more than 30% of the total.

When coal burns, apart from producing a large amount of smoke and dust, it can also release the harmful substances carbon monoxide, carbon dioxide, sulphur oxide, nitrogen oxide, hydrocarbon organic matter and so forth. If there are no controls on these pollutants, they will have significant damaging effects on humans’ health and environment.

Carbon dioxide is universally acknowledged to be a greenhouse gas, and reducing CO2 emissions has the world’s attention. China’s carbon dioxide emissions are the second highest in the world right now, and coal is the main source of this.

Another pollutant from coal, sulfur dioxide, is the main culprit causing acid rain and, at present, the sulfur dioxide produced from burning coal accounts for more than 90% of total national sulfur dioxide emissions in China, the country with the highest such emissions in the world.

© Rob Welham 

chinadialogue: Which methods can effectively remove the harmful pollutants produced from coal burning?

Ni: Reduction of carbon dioxide emissions is currently based on adopting clean coal technology and increasing the efficiency of power generation. At present, the mainstream technology for increasing the efficiency of burning coal is supercritical and ultra-supercritical power generation. In simple terms, “supercritical” is using a coal-fired boiler to heat water so that it evaporates, generating steam pressure as high as the critical pressure parameter. The optimum or highly efficient super-critical parameter is the “ultra-super-critical” point.

To tackle the issue of reducing sulphur dioxide, China has already launched comprehensive efforts for sulphur removal in coal-fired power generation. Up to the end of 2005, thermal-electric sulphur-removing systems with a capacity in excess of 200 million kilowatts of power were built nationally, making up approximately 20% of the total installed capacity at thermal power plants, and forming over 2 million tonnes of sulphur-removal capability.

However, due to the short time in which a large number of sulphur-removing facilities were constructed, management of safety and supervision was not to the required standards -- leading to a quality of sulphur-removal engineering which struggles to provide a guarantee of efficacy. After construction, many of the sulphur-removing systems were unable to operate normally, efficiency was low, there was a high occurrence of breakdowns, and the desired sulphur-removal results were not attained.

We need to find a more effective method for clean use of coal. Presently, coal gasification technology is seen as the cleanest method of coal transformation. It can be considered as the foundation for the future of clean-coal technology.

chinadialogue: What is coal gasification? Can all the environmental problems caused by burning coal be completely avoided by coal gasification?

Ni: Coal gasification technology can reduce the environmental impacts from the coal-use process to the lowest levels. Coal gasification is a thermochemical process, which uses coal or petroleum coke for raw material, and oxygen and steam for the gasification medium. At a high temperature, by a partial oxidation reaction, the raw material is transformed from a solid fuel into a gaseous fuel (main components: carbon monoxide and hydrogen).

This coal gasification technique is not new technology. It has long been employed widely in chemical engineering -- in ammonia synthesis and methanol production – so it is relatively well developed. In the wake of testing and approval of the concept of an integrated gasification combined cycle (IGCC) and its commercialisation, the use of the synthesised gas gained through coal gasification becomes one kind of clean-coal power-generating technology.

The reason why it is clean is because the synthesised gas -- which is made during gasification and contains sulphur components -- can be passed through purification technology, which removes ash and the majority of the sulphur oxides. This technique of removing the sulphur prior to burning is easier and more effective than removing sulphur dioxide from the coal smoke after it has burnt. Following from this, the use of coal gasification unites power generation and chemical engineering to form a system of multi-generation.

chinadialogue: How did coal gasification come to be the core ofthe multi-generation energy system?What are the advantages of establishing this kind of a system?

Ni: This multi-generation energy system from the coal-gasification process emerged from both the perspectives of environmental pollution and of finding an improved solution to the problem of liquid-fuel shortage. To briefly explain, it uses coal-gasification technology to change coal into a synthesis gas. After purification, this synthesised gas can be used for chemical-engineering product synthesis -- for example, methanol and ether, which are both very good liquid-fuel substitutes -- and power generation.

This kind of system of combined power-generation and chemical engineering can be used in achieving the optimal use of energy flow and matter flow, and in comparison to individual production, it can reduce energy consumption, as well as being able to achieve clean-coal power generation. And where it is needed, it can also bring about reductions in carbon-dioxide emissions.

In the long run, mankind must integrate the reduction of carbon dioxide into the energy process, and the multi-generation system provides very favourable conditions for doing this. It is much easier than extracting carbon dioxide from the smoke of a coal-burning power station. To sum up, it optimally brings together the manufacturing processes of many kinds of products. And this has striking benefits for basic investment, unit cost of product, pollution discharge (sulphur, mercury, particulate matter) and so forth, compared to the separate production of these related products.

chinadialogue: Is the technology for this multi-generation system well developed? How can it be brought into widespread implementation? Where do the current obstacles lie?

Ni: The technology that constitutes the large part of the multi-generation energy system is well developed. As long as each sector in China -- coal, chemical engineering, power generation -- breaks down the sector boundaries, to join forces and work together, and to increase international partnerships, then within three to five years it would be possible to establish a large-scale, pilot multi-generation energy installation, while having a significant number in use by the year 2020.

Presently, the multi-generation energy system has already got the nation’s attention. In China’s National High-Technology Research and Development Plan (863 program) -- from the most recent round of public announcements -- multi-generation systems and pilot engineering-project research have been linked together. Evidently, China will be creating an engineering demonstration project for the multi-generation system.

These multi-generation systems have exceptional potential for raising the efficiency of energy use and reducing environmental pollution -- so it would not be a mistake for a generation of people to engage in researching this.

chinadialogue: Currently, the shortage of liquid fuel for cars is becoming more serious day by day. Could the multi-generation system be used as an energy supply for cars?

Ni: Methanol, dimethyl ether and such are produced in the multi-generation energy system, and these can serve as oil-substitute products -- so this system could alleviate the nation’s oil shortage.

For example, a mix of methanol and petrol can be adjusted to different proportions of methanol, and 100% methanol can even be used as fuel for specially manufactured cars. In comparison to petrol and other traditional liquid fuels, methanol liquid fuel possesses some remarkable, differentiating features. It comes from many raw materials, has plentiful sources, burns completely and produces clean exhaust, while dimethyl ether is a good substitute for diesel. It can be seen from the burning process that, compared to diesel, it features slightly higher efficiency, less pollution and less noise. It now only needs improvements made to the oil-burning system.

Currently, colleges and universities in China -- for instance, Shanghai Jiaotong University and Xi’an Jiaotong University -- have research under way into the use of methanol and dimethyl ether. This includes research into problems such as friction damage caused to spare parts of fuel-injection systems, precise control of fuel-injection timing and the effects of sealing performance. The results of the research already have been put into use, and Shanghai is to have 10 to15 dimethyl ether-powered public buses in pilot operation.

Home page photo by LHOON

Weidou Ni is a professor of thermal engineering, and was formerly vice president at Tsinghua University. He is a member of the Chinese Academy of Engineering and vice chairman of the Beijing Association for Science and Technology. Ni is also a leader of the energy strategy and technology team at the China Council for International Cooperation on Environment and Devleopment.

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Default avatar
匿名 | Anonymous

洁净煤——这个承诺能否实现?

倪维斗在文章中谈到了“洁净煤发电技术”应用的可能性。但是多方阅读资料显示这项技术要大量投入使用需要3到5年,到2020年前将会“大量”投入使用。但是作者也在文章中承认短时间内安装脱硫项目并没有达到预期效果。为什么我们要相信“洁净煤技术”又能行得通呢?中国预计2007年将会修建500所电站。有多少会使用“洁净煤技术”发电呢?现在尚且没有把洁净煤技术和二氧化碳捕获技术结合起来进行商业操作——众所周知,这是非常复杂和昂贵的工艺。如果洁净煤技术真的那么有效,那么它就不得不和现存的电站进行竞争。中国科学院可持续发展研究中心就英国斯特恩报告所写的文件说:“人为维持低价和能源补贴以保护大型国有和不景气企业单位在竞争中受损。”政治力量也插手了煤能源,据了解许多当地政权和公司都拒绝为新能源技术做任何投资。这样的结果不仅危及全球气候,而且严重危及中国人的身体健康。例如,英国媒体站在中国媒体的报道说,中国山西省人民因为工业烟雾太浓影响生活而爆发不满。在该省环保局的调查中,超过90%的人表示经济增长也不能弥补如此骇人听闻的损失。中国青年日报报道,这次调查发现90%的市民和当地干部反对因为采取措施保护环境从而减缓经济发展。重庆早报报道,山西一名张姓矿主拥有3辆不同颜色的劳斯莱斯,以及为他全家成员准备的车队。评论家岳建国对山西这次民意调查下此评论:“普通人因为污染的空气和水而死亡,官员们却用矿泉水洗蔬菜,甚至洗脚,”与此同时,无论英国和世界人们做什么样的努力来改变气候变化都有可能会变成徒劳无功。卡尔•马克思死于肺病,这也许要部分地归功于伦敦糟糕的空气。 很遗憾马克思没有对促进工业革命发展和引起今天环境危机的——煤多加注意。

Clean Coal - Will the promise ever be realised?

Weidou Ni talks about technological possibilities for "clean coal power" but a close reading reveals that it will take 3 to 5 years to get a large scale pilot and by 2020 a "significant" number will be in use.

Yet he acknowledges that a rush to install sulfur removing technologies did not go well. Why should we believe that "clean coal technologies" will go well. China plans to build 500 power stations in the next few years. How many will be "clean coal". No where in the world is clean coal associated with carbon capture and seqestration actually up and running commercially - everyone knows that it will be very complicated and expensive.

If clean coal is become costs effective it will have to compete against existing power plants. Yet, according to the Research Centre for Sustainable Development at the Chinese Academy of Sciences, in a paper they wrote for the UK Stern Review:

"Artificially kept low price and energy subsidies protect large state-owned and inefficient technologies from competition with advanced ones."

A political power block is built up around coal power and my reading is that many local political and economic bosses refuse to spend on new technologies and the result is not only a threat to global climate but an appalling threat to the health of Chinese citizens now.

For example I read in the UK media that Chinese media have reported a revolt among the citizens of Shanxi who are choking in the smoke. More than 90% of people surveyed by the
provincial bureau for environmental protection said economic growth cannot go on at such an appalling cost.

The same survey, reported by the China Youth Daily, found that 90% of mayors and local cadres opposed any moves to protect the environment that might slow the economy. Apparently one mine boss in Shanxi named Zhang
owns three Rolls-Royces of different colours plus a fleet of other luxury
cars for his extended family, according to the Chongqing Morning Post, a daily newspaper.

"While normal people die of polluted air and water, officials use mineral
water to wash their vegetables and even their feet," said Yue Jianguo, an
analyst, commenting on the Shanxi survey.

Meanwhile, whatever we do in the UK and the rest of the world to try to deal with climate change is in danger of becoming totally irrelevant.

Perhaps its worth remembering that Karl Marx died of a lung complaint which was probably in part caused by London's appalling air pollution- and had to flee the London fogs shortly before he died. It's a pity he didn't put his mind to the driver of the industrial revolution and today's crisis - coal.

Default avatar
匿名 | Anonymous

可行性,不仅仅从科学上看

这里,首先我从一个普通人的角度上来说我赞同和支持上述的多联产系统的科学上的可行性。但是对于在实际情境下的运作我表示质疑。或许上层领导对于这种积极效果的大政方针是支持的,但是对于中国缺乏的是在具体层面执行力。这牵扯到很多问题,甚至我国的政绩考评制度——GDP。对于地方官员来说,GDP是加官进爵的法宝,经济搞上去了就可以忽略很多问题。这种从上而下的由来已久的想法也是导致很多社会问题的根源之一,比如社会分配的公正和公平性问题和经济发展中的腐败问题。如果要想从根本地转变现有的环境和发展状况,仅仅寄希望于科学技术是不可以和不可能的。如何要将这些有前景的计划实施并使从上到下每个人都有环境保护的可持续发展的观念时,我们离可持续的发展就不远了。有时候不是我们不想环保,是其他人都不环保,自己环保了就是吃亏。把这种先进的理念不仅仅作为政治上的口号,也不单单是媒体的焦点,而应当把这种思想转变为行动,进入每个人的生活中,这才是真正的可行性。

Achievability, not just from a scientific point of view

From the position of a commoner, I would support and agree with the feasibility of multi-generation technology. However, in light of present realities, I would like to express my reservations. Perhaps some individuals of the upper classes support the positive effects of the central government’s guidance. But what China is lacking, is the power to implement these guidances with the broader masses. Doing so would bring up a lot of problems, even in terms of China’s government evaluating system – the GDP. According to the local magistrates, GDP is helping officials to gain promotions. And as long as the economy carries on its ascent, many problems are allowed to be ignored. This ingrained top to bottom way of thinking is one source of the many problems within Chinese society. For example, the social divisions, social inequity, injustice, and corruption that accompanies economic development. To rely on technology alone to radically transform the present environmental and developmental situation, would be both impossible and inappropriate. If these far-sighted plans were actualised, in combination to a top down approach to make every person value environmental protection and support sustainable development; that would bring us to a point close to achieving sustainable development. Sometimes it is not the case that one simply does not care about the environment. But others do not seek to protect the environment, and standing against the grain, one would suffer losses compared to others. To make such an advanced idea more than merely a political buzzword, or simply a point for media focus, one ought to initiate a transformation of mentality, affecting every single person’s life. Only then it would bring about a truly achievable solution.