Hong Kong may have to build new waste in­cin­er­a­tor

China Daily (Hong Kong) - - HK COMMENT - KEN DAVIES

Many peo­ple don’t like the idea of build­ing an in­cin­er­a­tor in Hong Kong, but in the medium term there ap­pears to be no al­ter­na­tive. This is be­cause land­fills, which the ter­ri­tory re­lied on in ear­lier decades to dis­pose of mu­nic­i­pal solid waste (MSW), are now al­most full. In the long term, though, we need to fo­cus on elim­i­nat­ing waste at the source.

Al­ready 13 land­fills have been filled and closed. The re­main­ing three strate­gic land­fills will reach ca­pac­ity by 2019. The South­east New Ter­ri­to­ries land­fill, which takes 4,800 tons of MSW a day, will be full around 2015; the North­east New Ter­ri­to­ries land­fill, 2,500 tons a day, around 2017; and the West New Ter­ri­to­ries land­fill, 6,100 tons a day, around 2019.

Hong Kong de­pends on land­fill dis­posal far more than com­pa­ra­ble economies in the re­gion. South Korea stores 19 per­cent of its MSW in land­fills, Tai­wan 2 per­cent, and Sin­ga­pore 1 per­cent, while Ja­pan doesn’t use land­fills. In stark con­trast, Hong Kong dumps a whop­ping 52 per­cent of its MSW in land­fills.

The Hong Kong SAR is the fourth most densely pop­u­lated ter­ri­tory in the world, with over 6,600 peo­ple per square kilo­me­ter in mid-2012, be­hind only Ma­cao, Monaco and Sin­ga­pore. There isn’t room left for any more land­fills, es­pe­cially if we want to re­tain im­por­tant fea­tures like coun­try parks, which com­prise roughly 40 per­cent of Hong Kong’s land area and which at­tracted 12 mil­lion visi­tors in 2012.

The En­vi­ron­ment Bureau’s cur­rent plan, as out­lined in its Blue­print for Sus­tain­able Use of Re­sources 2013-2022, pre­scribes a range of ur­gent ac­tions to re­duce, re-use and re­cy­cle waste. Th­ese are de­signed to re­duce the pro­por­tion of MSW go­ing into land­fills from 52 to 22 per­cent, while in­creas­ing the pro­por­tion of re­cy­cled waste from 48 to 55 per­cent as the new in­cin­er­a­tor burns the re­main­ing 23 per­cent.

There are wor­ries about po­ten­tial air pol­lu­tion caused by an in­cin­er­a­tion plant. Hong Kong op­er­ated four waste in­cin­er­a­tors — in Lai Chi Kok, Kennedy Town, Mui Wo and Kwai Chung — from the early 1970s to the 1990s. Their aim, like now, was to re­duce land­fill MSW dis­posal. They were closed as a re­sult of the 1989 gov­ern­ment White Pa­per on Pol­lu­tion in Hong Kong. De­com­mis­sion­ing was pro­longed by the dis­cov­ery of tox­ins at the sites.

The gov­ern­ment, there­fore, has to en­sure that the tech­nol­ogy used is more ad­vanced and will re­sult in less pol­lu­tion. It has cho­sen to build a mov­ing grate in­cin­er­a­tor. This will not only re­move most of the waste, it will gen­er­ate en­ergy.

In­cin­er­a­tion re­duces, but does not com­pletely elim­i­nate, solid waste. The solid mass is typ­i­cally shrunk by over 80 per­cent and the vol­ume cut by 95 per­cent. The re­main­der is usu­ally put in land­fill. Mov­ing-grate in­cin­er­a­tors are more ef­fi­cient than the static burn­ers they re­placed, en­sur­ing more com­plete com­bus­tion. They also re­quire less fre­quent main­te­nance than older mod­els.

Crit­ics of this tech­nol­ogy say it is less ad­vanced than plasma arc gasi­fi­ca­tion, which uses a plasma torch pow­ered by an elec­tric arc to ion­ize gas and cat­alyze or­ganic mat­ter into syn­thetic gas and harm­less slag. This is the most ef­fi­cient way of pro­duc­ing carbon monox­ide and hy­dro­gen for elec­tric­ity gen­er­a­tion. The much higher tem­per­a­ture con­verts in­or­ganic con­stituents to non-haz­ardous slag, un­like in­cin­er­a­tion.

Sev­eral plasma arc fa­cil­i­ties have started work re­duc­ing land­fills, but the scale at present is lim­ited. One plant now un­der con­struc­tion, for ex­am­ple, will be in­stalled on the US’s lat­est-gen­er­a­tion air­craft car­rier, which is more the equiv­a­lent of a small town than a gi­ant me­trop­o­lis such as Hong Kong.

Un­der Sec­re­tary for the En­vi­ron­ment Chris­tine Loh says that while it may be de­sir­able in some ways, plasma arc gasi­fi­ca­tion can­not cope with the 3,000 tons of MSW a day fore­cast in Hong Kong’s blue­print, which is why Euro­pean coun­tries are adopt­ing mov­ing-grate in­cin­er­a­tion in­stead.

She cites the ex­am­ple of Copen­hagen, which is build­ing an in­cin­er­a­tion plant in the city center, topped off with a ski slope. When this is fin­ished in 2017, it will pro­duce heat for 160,000 house­holds and elec­tric­ity for 62,500 res­i­dences. Den­mark has long been a model of com­bined heat and power elec­tric­ity gen­er­a­tion, as well as of good de­sign and con­cern for the en­vi­ron­ment.

Adopt­ing state-of-the-art waste-to-en­ergy in­cin­er­a­tion is an ad­vance on the old pol­icy of re­ly­ing al­most en­tirely on land­fill. But it is no sub­sti­tute in the long term for elim­i­nat­ing solid waste at source by re­duc­ing, re-us­ing and re­cy­cling. As Head of Global Re­la­tions in the OECD’s In­vest­ment Di­vi­sion up to 2010, the au­thor wrote and pub­lished ma­jor pol­icy re­views for the gov­ern­ments of China, In­dia, In­done­sia and the Rus­sian Fed­er­a­tion. The ar­ti­cle is the sec­ond in a se­ries of ar­ti­cles ex­plor­ing poli­cies to ad­dress Hong Kong’s waste man­age­ment chal­lenges.

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