Power Plants, Renewable Energy and Energy Saving in Hong Kong
Martin Wong, SCMP – 8 Jan 09
Complaints over lights have doubled, the environmental secretary revealed yesterday. Edward Yau Tang-wah said the number of light-pollution complaints was 82 last year, compared with 40 in 2007 and 35 in 2006. In view of energy wastage, the government would launch a consultancy study, exchange views with environmental protection groups, and assess the feasibility of regulating external lighting this year, Mr Yau said.
Kandy Wong, SCMP – Updated on Jan 07, 2009
The central government will soon announce the rate cut for consumption tax, which is regarded as a move to further boost sales and entice consumers to buy “green” cars in a weak market.
Beijing aims to transform the industry, with zero emissions as the goal in the next decade, using tax policies. It regards the current financial crisis as the right time to encourage fuel-efficient vehicles.
“China needs to take policy steps to help counter a serious drop-off in car sales as a result of the global economic slowdown,” Minister of Industry and Information Technology Li Yizhong has said.
The vehicle industry is lobbying government departments for a favourable consumption tax rate. Mainlanders currently pay a consumption tax of 10 per cent when they buy a vehicle. Analysts said if the tax cut was less than 5 percentage points, there would not be a strong enough effect to boost sales of small-engined vehicles.
Under one set of proposals, the tax for vehicles with one-litre engines or smaller would be lowered to 2 per cent from 10 per cent. Vehicles with 2-litre to 2.5-litre engines and 2.6-litre to 3-litre engines, which are among the most widely bought cars, would be taxed at 7 per cent and 8 per cent, respectively.
Another proposal is to eliminate the consumption tax on cars with 1.6-litre engines or smaller. But it remains unclear how aggressive the government will be in the tax cuts.
The Ministry of Finance has already doubled the vehicle consumption tax in August on large-engined cars of 4.1 litres to 40 per cent from 20 per cent in a bid to fight pollution.
Before the government implements changes to the vehicle consumption tax, the country’s fuel consumption tax has been increased effective January 1, which is seen as a move to prompt the development of fuel-efficient vehicles.
The National Development and Reform Commission announced last month that the tax for petrol would be raised from 20 fen (23 HK cents) per litre to 1 yuan and the diesel tax from 10 fen to 80 fen per litre.
Road maintenance fees levied on motorists will also be cancelled, as a way to offset the higher fuel consumption tax.
The increase in fuel consumption tax has been discussed for a decade and was turned down seven times in the past.
Motorists have said they would drive less and use more public transport because of the higher fuel consumption tax.
SCMP – Updated on Jan 07, 2009
The letter from Dave Ho, of the Environmental Protection Department (“Comprehensive measures to clean up air”, December 29), misses the point completely.
Discussing endlessly whether one monitoring system is better than another or whether it is easier for an ordinary resident to understand the figures when he or she is choking due to poor air quality is largely irrelevant. The government’s reticence to ban high-sulfur fuels from the special administrative region is a major pollution issue in Hong Kong. These fuels, which are banned in many places including, I understand, the US, Bangkok and Singapore, are cheap, but environmentally damaging.
The reason I believe the government has taken no action to ban them is the pressure from big business and fear that some trade may be lost to Shenzhen on a cost basis. So, once again, we are sacrificing the health of Hong Kong people for the potential profits of a few businessmen who then fly out as soon as they can to less-polluted places. So much for a “people’s government” and Asia’s “world city”.
Nick Bilcliffe, Lamma
http://waste-management-world.com/a/plasma-gasification-clean-renewable-fuel-through-vaporization-of-waste
Plasma gasification technology in the US is developing fast, and could be the perfect way to divert MSW from landfill and produce valuable by-products. Here, we look into the benefits.
by Ed Dodge
Plasma gasification is an emerging technology which can process landfill waste to extract commodity recyclables and convert carbon-based materials into fuels. It can form an integral component in a system to achieve zero-waste and produce renewable fuels, whilst caring for the environment. Plasma arc processing has been used for years to treat hazardous waste, such as incinerator ash and chemical weapons, and convert them into non-hazardous slag.
Utilizing this technology to convert municipal solid waste (MSW) to energy is still young, but it has great potential to operate more efficiently than other pyrolysis and combustion systems due to its high temperature, heat density, and nearly complete conversion of carbon-based materials to syngas, and non-organics to slag.
Syngas is a simple fuel gas comprised of carbon monoxide and hydrogen that can be combusted directly or refined into higher-grade fuels and chemicals. Slag is a glass-like substance which is the cooled remains of the melted waste; it is tightly bound, safe and suitable for use as a construction material.
Plasma torch technology has proven reliable at destroying hazardous waste and can help transform environmental liabilities into renewable energy assets.
Plasma gasification process
Plasma gasification is a multi-stage process which starts with feed inputs ranging from waste to coal to plant matter, and can include hazardous wastes. The first step is to process the feed stock to make it uniform and dry, and have the valuable recyclables sorted out. The second step is gasification, where extreme heat from the plasma torches is applied inside a sealed, air-controlled reactor.
During gasification, carbon-based materials break down into gases and the inorganic materials melt into liquid slag which is poured off and cooled. The heat causes hazards and poisons to be completely destroyed. The third stage is gas clean-up and heat recovery, where the gases are scrubbed of impurities to form clean fuel, and heat exchangers recycle the heat back into the system as steam. The final stage is fuel production the output can range from electricity to a variety of fuels as well as chemicals, hydrogen and polymers.
Gasification has a long history in industry where it has been used to refine coal and biomass into a variety of liquid fuels, gases and chemicals. Modern clean coal plants are all gasifiers, and so were the earliest 19th century municipal light and power systems.
Plasma gasification refers to the use of plasma torches as the heat source, as opposed to conventional fires and furnaces. Plasma torches have the advantage of being one of the most intense heat sources available while being relatively simple to operate.
Plasma is a superheated column of electrically conductive gas. In nature, plasma is found in lightning and on the surface of the sun. Plasma torches burn at temperatures approaching 5500ºC (10,000F) and can reliably destroy any materials found on earth with the exception of nuclear waste.
Plasma torches are used in foundries to melt and cut metals. When utilized for waste treatment, plasma torches are very efficient at causing organic and carbonaceous materials to vaporize into gas. Non-organic materials are melted and cool into a vitrified glass.
Waste gasification typically operates at temperatures of 1500C (2700F), and at those temperatures materials are subject to a process called molecular disassociation, meaning their molecular bonds are broken down and in the process all toxins and organic poisons are destroyed. Plasma torches have been used for many years to destroy chemical weapons and toxic wastes, like printed circuit boards (PCBs) and asbestos, but it is only recently that these processes have been optimized for energy capture and fuel production.
America’s Westinghouse Corporation began building plasma torches with NASA for the Apollo Space Program in the 1960s to test the heat shields for spacecraft at 5500C. In the late 1990s, the first pilot-scale plasma gasification projects were built in Japan to convert MSW, sewage sludge, and auto-shredder residue to energy. The Japanese pilot plants have been successful, and commercial-scale projects are under development now in Canada and other countries, by companies such as Alter NRG, from Alberta, Canada.
Economics
The economics of MSW plasma gasification are favourable, although complex. Waste gasification facilities get paid for their intake of waste, via tipping fees. The system then earns revenues from the sale of power produced. Electricity is the primary product today, but liquid fuels, hydrogen, and synthetic natural gas are all possibilities for the future.
Sorting the MSW to capture commodity recyclables, such as metals and high-value plastics, presents a third revenue stream. Minor revenue streams include the sales of slag and sulphur. Slag has the potential to be used for a number of construction products, such as rock wool, bricks and architectural tiles, and sulphur has some commodity value as fertilizer.
Additional costs are avoided by diverting waste from landfills and minimizing transportation of waste. Government subsidies for renewable energy or carbon credits may be substantial in the future, but are difficult to project.
A base case scenario with a 680 tonne per day (750 US tons) waste gasification plant which would be appropriate for a small city or regional facility, would cost an estimated $150 million (€108 million) to construct. A municipality that funds the entire project through bonds should seek a positive cash flow year-after-year via revenues from tipping fees, recyclables and electricity sales, as well as sales of slag and sulphur. There is considerable range in the values for each of these variables, and any proposed development would require extensive due diligence to determine local prices for each line item. Tipping fees, electricity rates, commodity recyclables, as well as interest rates and taxes, all vary dramatically creating a model which needs to be thoroughly evaluated for any proposed development.
The economics of waste gasification heavily favour recycling inorganic materials like metal and glass have no value as fuel and make the gasification process less efficient, even though plasma torches have the ability to melt them. High-value plastics and papers that can be readily separated are far more valuable as recyclables than as fuel. Certain plastics earn €195 per tonne ($300 per US ton) and certain types of paper can earn around €53 per tonne ($75 per US ton). For comparison, a tonne of waste may produce 0.8 MW of electricity, worth around €51 ($70) per MW. It is clear that any of these materials that can be separated and sold, are worth much more as commodities than as fuel.
Wide variety of inputs and outputs
There are additional waste streams available in certain locations which earn higher tipping fees than MSW because they are toxic and yet have excellent fuel value. Refinery wastes from petroleum and chemical plants, medical waste, auto-shredder residue, construction debris, tyres and telegraph poles, are all examples of potential fuels that can earn high tipping fees and provide good heat value. Additionally, there are millions of tonnes of low-grade waste coal that exist in massive piles throughout the Appalachian region of Pennsylvania and West Virginia, US, that can be utilized for gasification.
Multiple outputs can be produced from a single facility. Heat and steam can be sold, and electricity production can be combined with ethanol or hydrogen production to maximize resources.
Hydrogen can be readily produced from syngas by separating it from the carbon and oxygen, while synthetic natural gas can be produced by upgrading the methane content of syngas.
Liquid fuels are typically produced from syngas through catalytic conversion processes such as Fischer-Tropsch which has been widely used since World War II to produce motor fuels from coal.
Biotech methods to produce liquid fuels are also being developed to use enzymes or micro-organisms to make the conversion.
Much research and effort is being put into developing more selective catalysts and productive enzymes which will raise system efficiencies to levels needed to be competitive. Currently, ethanol from gasification costs more than $2 a gallon (equivalent of €0.37 per litre), and it is estimated that production needs to cost closer to $1.25 (€0.90) or $1.50 (€1.10). Production of ethanol at demonstration scale has shown that one US ton of MSW can produce around 100 gallons (equivalent of 0.9 tonnes producing 380 litres) of ethanol, give or take 20%. Cost estimation for ethanol production is difficult, but rough calculations indicate that ethanol could potentially be more profitable than electricity.
Improved waste management
Gasification is superior to landfilling MSW for a number of reasons. First of all, landfills are toxic to the environment due to the production of toxic liquid leachate and methane gases. The EPA (US Environmental Protection Agency) has a lengthy protocol for airborne and liquid chemicals which must be contained and monitored for every landfill. Landfills must be constructed with extensive liners, drains and monitoring equipment to comply with regulations. Plasma gasification can divert waste from landfills and create beneficial uses for the material, by maximizing recycling and cleanly using the rest for fuel.
Gasification is superior to incineration
Gasification is superior to incineration and offers a dramatic improvement in environmental impact and energy performance. Incinerators are high-temperature burners that use the heat generated from the fire to run a boiler and steam turbine in order to produce electricity. During combustion, complex chemical reactions take place that bind oxygen to molecules and form pollutants, such as nitrous oxides and dioxins. These pollutants pass through the smokestack unless exhaust scrubbers are put in place to clean the gases.
Gasification by contrast is a low-oxygen process, and fewer oxides are formed. The scrubbers for gasification are placed in line and are critical to the formation of clean gas, regardless of the regulatory environment. For combustion systems, the smokestack scrubbers offer no operational benefit and are put in place primarily to meet legal requirements. Plasma gasification systems employing proper scrubbers have extremely low emissions and no trouble meeting and beating the most stringent emissions targets.
The objective of gasification systems is to produce a clean gas used for downstream processes which requires specific chemistry, free of acids and particulates so the scrubbing is an integral component to the system engineering, as opposed to a legal requirement that must be met.
Incinerator ash is also highly toxic and is generally disposed of in landfills, while the slag from plasma gasification is safe because it is melted and reforms in a tightly-bound molecular structure.
In fact, one of the main uses for plasma torches in the hazardous waste destruction industry has been to melt toxic incinerator ash into safe slag. The glassy slag is subject to EPA Toxicity Characteristic Leaching Procedure (TCLP) regulations that measure eight harmful elements. Data from existing facilities, even those processing highly hazardous waste, has shown them to be well below regulatory limits.
Electricity production from plasma gasification is superior to that from incinerator combustion. Incinerators typically use the heat from combustion to power a steam turbine to produce power.
Gasification systems can use gas turbines that are far more efficient, particularly when configured in integrated gasification combined cycle mode (IGCC). Just as IGCC is the state-of-the-art in producing power from coal, the same is true when using MSW as the fuel source.
Carbon impact
The carbon impact of plasma gasification is significantly lower than other waste treatment methods. It is rated to have a negative carbon impact, especially when compared to allowing methane to form in landfills. Gasification is also an important enabling technology for carbon separation. It is primarily a carbon processing technology; it transforms solid carbon into gas form.
Syngas is comprised of carbon monoxide and hydrogen. The hydrogen readily separates from the carbon monoxide allowing the hydrogen to be used while the carbon is sequestered. The US Department of Energy has identified gasification through its clean coal projects as a critical tool to enable carbon capture
Environmental opposition
Environmentalists have expressed opposition to waste gasification for two main reasons. The first argument is that any waste-to-energy facility will discourage recycling and divert resources from efforts to reduce, reuse and recycle. Economic studies of the waste markets show the opposite to be true; waste-to-energy heavily favours the processing of waste to separate valuable commodities and to maximize its value for fuel.
The second argument made against waste gasification is that has the same emissions as incineration. These arguments are based on gasification systems which do not clean the gases and instead combust dirty syngas. Such systems are essentially two-stage burners and are not recommended for environmental reasons. There are many variations of combustion, pyrolysis and gasification all used in different combinations. Proper engineering is required to achieve positive environmental performance.
Technology
Plasma gasification of MSW is a fairly new application that combines well-established sub-systems into one new system. The sub-systems are waste processing and sorting, plasma treatment, gas cleaning and energy production. The integration of these systems is rapidly maturing, but has still not been built in large industrial systems. Demonstration and pilot-scale systems are running successfully in Japan and Canada with more starting in the US and Europe.
Pre-processing
Waste sorting and processing is a mature industry for recycling. A wide range of drying and separation equipment is commercially available. The goal in treating MSW is to shred it into uniformly small pieces and separate out all the metal, glass and other inorganics that have no value as fuel. Valuable recyclables should be separated for sale. MSW in this form is often called RDF, refuse-derived fuel.
The next step
Following the pre-processing, the wastes are vapourized using the high heat from the plasma torches.
As the materials are vapourized the gasses flow out the top, while the molten slag pours out the bottom of the reactor. Gasification of MSW requires temperatures above 1200C (2200F) and systems are targeted to operate around 1500C (2700F). As the hot gases exit the reactor they are cooled through a combination of quenching and heat exchangers. The heat is very valuable and is recycled back into the system to generate steam for other purposes.
There are engineering challenges in using heat exchangers at 1500C, as temperatures will strain steel and other materials. The heat exchanging sub-system is one of the areas which would benefit from further development.
Scrubbing
Once the gases are cooled, they pass through a series of gas cleaning operations which are tuned to the downstream requirements as well as environmental regulations. There are many different designs for scrubber systems and it is a mature industry. Scrubbers are routinely used to clean smokestack exhaust in power plants and industry.
Energy production
Electricity is produced using boilers, engines or gas turbines. Gas engines and turbines require very clean gases, but straight combustion to fire a boiler can use less clean gas and has the lowest cost. Steam systems may generate 450550 kWh per tonne (500600 kWh per US ton) of MSW. Gas turbines in a combined cycle may generate 9001200 kWh per tonne (10001200 kWh per ton) of MSW. IGCC is considered the state-of-the-art and the most efficient means to generate power from carbon resources. It is the model used for modern clean coal power plants.
In IGCC the syngas is combusted in a turbine to produce electricity, at the same time the hot turbine exhaust is captured in a heat recovery steam generator (HRSG) to produce electricity via a steam turbine. The combination of a steam turbine with the gas turbine is the combined cycle.
Heat recovery steam generators can also use the captured heat from the gases in addition to the heat from the turbine exhaust. The gases pass out of the reactor at around 1200C and the heat can be used to generate significant energy for the facility. In theory, the torches and the facility would consume only 25% of the energy produced, leaving 75% available for sale.
Conclusions
The time is becoming ripe for waste gasification. The world is facing profound problems in the search for new sources of energy, in addition to facing ongoing environmental degradation.
Plasma gasification of waste can be part of the solution to both problems. Using toxic waste materials, as feed stocks for producing renewable fuels, transforms liabilities into assets. As a municipal or publicly funded operation, a waste gasification plant can help balance budgets and provide a hedge against future increases in energy prices. The complexity and expense make plasma gasification a challenge for private investors and for municipalities.
Fortunately, the technologies needed to make waste gasification work are coming along fast. The most encouraging aspect of plasma gasification is that the individual sub-systems are all very mature and established. It is simply the integration between them that needs further refinement. All of the waste sorting and preparing equipment is readily available, plasma torches have been used reliably for decades, and gasification and gas cleaning is also well understood.
Energy production from syngas can be done profitably today by producing electricity, and it is hoped that ethanol will soon be economical. Hydrogen and synthetic natural gas are also in the wings, waiting for the right time to emerge. It is entirely possible that a decade from now, society could be producing significant quantities of renewable fuels by using landfill waste, and in doing so, clean up the environment at the same time.
Ed Dodge is from Cornell University in Ithaca, NY, USA
SCMP – Updated on Jan 06, 2009
Letters have appeared in these columns advocating so-called “energy efficient” light bulbs and criticising excessive lighting of buildings, described as light pollution.
The spectacular night view of the harbour is one of our tourist attractions, but it comes at a cost. As darkness falls, the lights come on, everywhere in Hong Kong, consuming electricity which pollutes our air and contributes to global warming. It would cost a fortune to replace every bulb with energy efficient bulbs and as Robert Hanson points out (“Energy saving bulbs do not live up to name”, January 3), these bulbs are more damaging to the environment than conventional bulbs. Fortunately there are other ways to save electricity, ones with no adverse ecological effects. On the shortest day of last year and including the twilight periods at the end of the day, we had daylight from 6.33am to 6.09pm. In June we will have daylight at 5.15am. Do we need daylight so early in the morning?
If we advance our clocks and adopt GMT plus nine hours as our standard time throughout the year, we will avoid wasting morning daylight and postpone the need for evening lighting by one hour. We had daylight saving from 1941 to 1979. Clocks were put forward an hour from the beginning of April to the end of October. In 1973 the government responded to the oil price crisis by implementing daylight saving from December 1973 to October 1974. We now have energy, pollution and global warming crises and similar measures are called for.
In 1974 we had double-shift schools and factory shifts and early daylight was deemed necessary, but today our schools are single shift, our factories have gone and we are a 9 to 5 economy. We do not need early daylight. If we also have summer daylight saving (GMT plus 10), on the longest day of the year dawn would break at 7.15am and daylight would last until 9.35pm. The electricity savings and social benefits would be significant.
Chinese premier Wen Jiabao has said the developed world should tackle climate change and alter its unsustainable lifestyle. Hong Kong is part of the developed world and part of China. We must act responsibly and set an example.
Robert L. Wilson, Discovery Bay
Matthias Voss and Matthew Bisley, SCMP – Updated on Jan 05, 2009
The 4 trillion yuan (HK$4.55 trillion) stimulus package announced last month by the central government gives impetus to energy efficiency development and opportunities on the mainland.
The 2007 Energy Conservation Law came into force on April 1 last year against a backdrop of a fast-growing economy and rise in demand energy and fuel prices, a growing awareness of environmental issues and increasing world pressure on developing economies including China to use environmentally friendly and technologically advanced energy sources. While economic circumstances have since changed, the stimulus revitalises opportunities in the energy sector arising from the Energy Conservation Law.
The law has three principal goals: to promote policies for energy conservation and environmental protection; to restrict the development of high-energy consumption and high-pollution industries; and to encourage the development of energy-saving and environmentally friendly industries.
It proposes many policy initiatives to achieve energy conservation ranging from passive measures – education, energy efficiency labelling, accreditation systems for products, publication of energy use statistics and awards systems for energy conservation achievement – to more direct measures such as government funding, tax incentives, subsidies, prohibitions on the use of high energy consuming or polluting technologies, introduction of maximum emission standards for motor vehicles and focused government procurement of energy-saving products.
The law is supported by regulations in specific sectors. Banks, for example, are required to monitor and actively support energy-efficiency projects while developers must incorporate energy-efficient technologies into new projects.
The present economic environment is vastly different from that existing when the law was introduced, threatening the opportunities expected to arise from the new law. There has been a general slowdown in the Chinese economy and oil prices have dropped, making the introduction of energy-efficient technologies relatively more expensive.
However, the State Council’s announcement that one of the 10 measures of the stimulus package is the enhancement of environmental and ecological development makes the prospects of this sector brighter.
The law supported by the stimulus package creates opportunities for participants in the energy sector, including manufacturers of energy-efficient products and technologies, real estate developers, architects, banks, leasing companies, project sponsors, consultants and advisers.
The new regulatory environment should also foster collaboration. For example, manufacturers may link up with financiers or leasing companies to promote sales of their products, and manufacturers and financiers may co-operate with government entities for particular government initiatives. Independent of the new regulatory environment, the energy-efficiency market has already started to develop with support from international financial organisations such as International Finance Corp and Asian Development Bank.
Matthias Voss is a partner of the banking practice at Allen & Overy in Shanghai and Matthew Bisley is a counsel of the banking practice in Shanghai
SCMP – Updated on Jan 05, 2009
I refer to the letter by Michael R. K. Mudd (“We must opt for energy saving light bulbs”, December 27). I would like to raise a number of points about these energy saving light bulbs that was not mentioned.
Though they consume less electricity, they pose health and environmental risks.
Fluorescent bulbs contain neurotoxic mercury vapour and if broken indoors they contaminate the air and require special clean-up procedures (no vacuuming, for example). When disposed of in ordinary trash, they are eventually broken and add to our city’s already severe mercury pollution.
For years traditional fluorescent bulbs have been widely used in offices but now compact fluorescent light bulbs are making their way into homes where they pose big risks especially to children. And promoting the increasing use of these bulbs without proper and efficient disposal systems will just increase the amount of this cumulative highly toxic poison in our city.
The manufacturers are not mentioning these dangers. And the government has made no special effort to educate people on the careful handling of these bulbs nor organised collection of this hazardous waste, just as it has not adequately addressed the disposal of batteries, computer waste and dental amalgam, all of which are toxic and contaminate our air, water, and food supply.
P. Tung, Repulse Bay