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September, 2010:

Plant’s waste management plan would cost less than incinerator


I refer to the report (“Sewage could be energy source, scientist says”, September 28).

While the studies of Herbert Fang, chairman of environmental engineering at the University of Hong Kong, should be encouraged, I wish to point out that the use of sewage sludge as a refuse derived fuel is not an entirely new concept. There are many operations all over the world that treat sewage sludge and use it as an environmentally-friendly and cost-effective refuse derived fuel.

At Green Island Cement, we have been working on our waste management technology, the eco-co-combustion system, for the past nine years.

We have already presented the government with our environmentally-friendly and cost-effective solution for sludge treatment. However, it has rejected our proposal and decided to construct a conventional sludge treatment incinerator in Tsang Tsui to manage Hong Kong’s growing waste management problem.

Through our eco-co-combustion system, sludge would be used as a refuse derived fuel at our cement plant in Tap Shek Kok. Sludge would be taken from Stonecutter’s Island (using existing transport containers) and further dewatering would be carried out at our site to create sludge pellets. These refuse derived fuel pellets would then be fed into the cement plant’s burner system to replace imported coal.
Together with this technology, the refuse derived fuel could replace about 40 per cent of coal currently burnt at the cement plant.

Our eco-co-combustion system pilot plant tests have demonstrated excellent emissions results, far better than the government’s best practical means.

In sum, our system offers a waste management solution that will result in an overall net improvement in air quality. All residual ash is recycled and used in the manufacturing of cement clinker, thereby further reducing the burden on landfills.

We estimate that the quantity of dewatered sludge which can be treated by our proposed facility would be up to about 2,000 tonnes of sludge per day, the same as the government’s proposed incinerator.

The capital required to install such a sludge processing facility at Tap Shek Kok is around HK$950 million.

This is a substantial saving on the government’s proposal to spend HK$5.2 billion.

It is a significant saving for the public purse.

Despite these numerous benefits, the administration has pressed ahead with its own conventional sludge incinerator proposal, without giving due consideration to our technology.

So while Professor Fang should be encouraged with his studies, we hope officials can provide a forum in which new technologies can be assessed and brought into fruition. If the government will only consider conventional technologies, any new scientific studies or advancements will prove pointless.

Don Johnston, executive director, Green Island Cement (Holdings) Limited

Tight caps on power firms’ pollution

Last updated: September 17, 2010

Source: South China Morning Post

Clearer skies, dearer electricity in prospect

Hong Kong’s two power companies have been ordered to reduce emissions of major pollutants by up to 64 per cent in the next five years.

While the measures should improve general air quality, they will do nothing to reduce roadside pollution.

And they could push up power bills. The targets the government has set the companies – CLP Power (SEHK: 0002) and Hongkong Electric (SEHK: 0006) – require much greater use of natural gas, which is dearer than coal.

The companies will be required to raise the share of natural gas used for generation from 39 per cent this year to 52 per cent in 2015. The government said gas prices would determine whether consumers have to pay more for electricity.

The new pollution caps mean overall cuts in emissions of 50 per cent for sulphur dioxide, 35 per cent for nitrogen oxides and 34 per cent for respirable suspended particulate.

All three cause respiratory symptoms and disease and can aggravate conditions such as asthma. Particles can cause more severe problems by lodging in the lungs. Nitrogen oxides can also combine with oxygen to form the pollutant ozone and can cause acid rain.

The Environment Bureau announced the new caps three months before the companies’ deadline for meeting the current targets, set two years ago. According to the latest available figures, for last year, they had only achieved the one for nitrogen oxides.

The companies face fines of HK30,000 for every tonne by which they exceed any of the caps. Fines are doubled for second and subsequent offences and senior executives face up to six months in jail.

Greenpeace campaigner Prentice Koo Wai-muk welcomed the greater use of natural gas in generating electricity but criticised the government for delaying its review of air quality objectives, which should have been completed a few months ago. The current objectives date to 1987.

“With more natural gas [being used], the objectives should be tightened immediately,” he said.

WWF senior campaigner Angus Wong Chun-yin said tighter caps would improve regional air quality but the city needed more measures to mitigate roadside pollution.

In a paper prepared for discussion by the Legislative Council next week, the bureau said it had taken new factors into consideration in setting the caps, which are subject to review after three years.

“To realise the maximum emission reduction potential of the power sector, the distribution of the emission allowances can no longer be made based solely on consideration of the respective share of local electricity generation of the two power companies,” it said.

For the first time, the companies have been set different targets. CLP, which generates a greater proportion of its electricity from gas, will have to reduce its sulphur dioxide output by 64 per cent, whereas Hongkong Electric will have to cut its emissions of the pollutant by only 28 per cent.

A bureau spokesman said CLP had been set a tighter cap on sulphur dioxide emissions since it was not using to the full its existing gas-fired generation units. This was because it could not secure sufficient supplies of gas, but a recently signed memorandum of understanding on energy co-operation with the mainland would enable it to source more gas by 2015. Hongkong Electric had much less scope for increasing natural gas use, the spokesman said.

CLP said in 2006 the reserves in its Yacheng gas field off Hainan were lower than expected and it would have to burn more coal in order to conserve them.

Natural gas accounted for just 24.7 per cent of CLP’s fuel mix last year despite its big gas-fired power station at Black Point.

Hongkong Electric has only two gas-fired units but natural gas made up 30 per cent of its fuel mix this year.

The bureau said it had also looked at the extent to which the companies could switch from coal-fired to natural-gas generation and further reduce emissions through the use of new technology.

A CLP spokeswoman said the company supported moving towards higher air quality standards but compliance could be restricted by other factors such as the lack of timely availability of natural gas. A spokeswoman for Hongkong Electric said the city needed a long-term policy on increasing natural gas usage to assist its negotiations with gas suppliers.

Hot air

Last updated: September 17, 2010

Source: South China Morning Post

Is carbon dioxide really the monster driving climate change? If not, maybe we should prepare for a colder world

In my 20-plus years of studying carbon dioxide and global warming, I have found that hypothetical scares often come before any realities or factual presentations. Horror stories about rising seas inundating land, cities and wildlife, super typhoons and hurricanes, and epic “mega droughts” lasting a decade or longer are all promoted as devastating results of global warming caused by the rising levels of carbon dioxide, according to reports and scientists associated with the UN Intergovernmental Panel on Climate Change (IPCC).

But will any of these scary scenarios about the carbon dioxide monster prove true for Hong Kong?

My recent seminar at the University of Hong Kong’s Department of Earth Sciences offered this simple answer: No. Objective science informs us that the so-called “consensus viewpoints” offered by the IPCC – about man-made carbon dioxide being the dominant factor in climate change – is primarily a political conclusion, and not likely a scientifically accurate one.

The natural and human history of Hong Kong was captured by former British foreign secretary Lord Palmerston around 1841. He described the area as “a barren island with hardly a house upon it!” That was of course explainable by the massive tree-cutting that began during the Song dynasty a millennium ago. It explains why the history of land use changes must surely be a decisive factor in determining the recorded evolution of meteorological and climatic conditions in Hong Kong, before urban greenhouse effects could have played any role.

There is another reason to support a minimal climatic role from atmospheric carbon dioxide. If carbon dioxide is the dominant driver of temperature, why has warming ceased over at least the past decade? Carbon dioxide levels have risen steadily, and yet average planetary temperatures have been stable or even declining since 1995.

Extremist views serve only to increase public panic about climate change – and the media’s, IPCC’s and political establishment’s unwillingness to address the real science only leads to spurious claims that “the science is settled”.

If global temperatures cease to rise, when they are supposedly affected by rapidly rising atmospheric carbon dioxide concentrations, then something more important than carbon dioxide must be driving climate change.

This is also why many peer-reviewed papers on past climatic records (as exemplified by the work of professors Zhonghui Liu and Jason Ali at HKU’s Department of Earth Sciences) tell us convincingly that weather and climate varied naturally in the past and will probably do so in the future, without any ties to atmospheric carbon dioxide levels.

In recent years, the world’s attention has indeed been drawn to the reality and danger of changing climate. Scientists well understand that climatic records comprise alternating periods of warming and cooling all over our earth. Yet, we have rarely considered how modern civilisation would best deal with the challenges of an emerging cooling trend.

There is no excuse for this neglect. Our knowledge about centuries of climate changes clearly indicates that significant cooling can happen on a time frame of a few decades. Several natural drivers of climate have been enumerated that could drive cooling on these time frames and, today, global climate observations seem to be on a razor’s edge between indications of warming and harbingers of cooling.

Thomas Jefferson once remarked: “I have no doubt but that cold is the source of more sufferance to all animal nature than hunger, thirst, sickness and all the other pains of life and death itself put together.” Closer to home, the transition from the Ming to Qing dynasty, a chaotic time owing to crop failures and periods of civil unrest, was likely to be related to a cooling climate. As geographer and historian David Zhang and his HKU colleagues recently noted, “during cold phases, China suffered more often from frequent wars, population decline and dynastic change”.

Another study of the 1,000-year history of typhoon landfalls in Guangdong, by climate scientists from Chinese University of Hong Kong and Louisiana State University, tells us that the two periods of 1660-1680 and 1850-1880 saw the most devastating typhoons.

It is not surprising to find that these two most active typhoon periods also correspond to the coldest and driest periods in northern and central China, as it is often the relatively colder, dryer times that cause the strongest contrasting meteorological conditions in the land, ocean and atmosphere, leading to frequent and damaging typhoons. Therefore, hypothetical scares proposed by global warming scenarios caused by carbon dioxide must raise more serious questions.

What if Hong Kong’s climate turns cold within the next 100 years?

How would the proposed 33 per cent carbon dioxide emissions reduction by 2020 benefit Hong Kong citizens, if it results in soaring energy costs but has no effect on climate?

Why should anyone continue to blindly demonise a life-supporting molecule: carbon dioxide?

Willie Soon is an astrophysicist and geoscientist at the Harvard-Smithsonian Centre for Astrophysics. All views are strictly based on his own scientific research and conclusions