dynamco Jul 13th 2013 10:10am
Mr Paine should acquaint himself w/ differences between incineration, gasification & plasma gasification for the treatment of MSW. Incineration 750-850 deg C is thermal conversion of MSW to ash in the presence of oxygen, the resultant 30% ash by weight is toxic, needs treatment & landfilling.
Gasification of MSW at 1300-1500 deg C in the presence of controlled oxygen creates a syngas used to generate electricity or biofuels. Ash residues are converted to usable vitrified slag by the heat.
Plasma gasification in excess of 4000 deg C without oxygen molecularises MSW into a component syngas & vitrified slag as above. The slag can be used as aggregate. There are No ash residues.
HKG has the wettest worldwide putrescible waste w/ 90% moisture levels from wet markets & avg 70+% domestic vs 56% Korea,50% Japan,30% Europe. Anaerobic digestate is an appropriate treatment for wet food waste(WFW).
To sustain combustion a calorific value(CV) of 6MJ/kg is needed whereas HKG WFW has CV of <4MJ/kg & WFW is 43% (4000tpd) of HKG’s daily domestic MSW; how do you burn water ? Incineration means adding higher CV materials into the combustion mix eg paper & plastics, which dents all hopes of increased recycling efforts. Incineration is the totally wrong choice for HKG’s waste treatment, & incinerators’ cancerous emissions.
www.ncbi.nlm.nih.gov/pubmed/15242064
‘Risk of adverse reproductive outcomes associated w/proximity to MSW incinerators w/ high dioxin emission levels in Japan’
Published on South China Morning Post (http://www.scmp.com)
Home > Letters to the Editor, July 13, 2013
Letters to the Editor, July 13, 2013
Saturday, 13 July, 2013, 12:00am
Comment›Letters
HK needs not one but three incinerators
I would like to add to Alex Woo’s excellent letter (“Incineration a key part of a responsible waste disposal system [2]“, June 29) and your editorial (“The rubbish of a waste policy [3]“, June 25).
To add to your correspondent’s Nimby comments, in metropolitan Tokyo there is an incinerator in each of its wards, covering a population of 13 million.
Choosing a single site for one incinerator is a poor policy.
Legislators should accept that we will need at least three, for Hong Kong Island and west and east Kowloon.
I do not understand why industrial solid waste and glass are being dumped in landfills, when there is so much water surrounding Hong Kong. Why isn’t it being used for reclamation or just dumped in designated areas at sea? This would extend the life of the existing landfills.
Finally, why are Friends of the Earth or the green groups not putting forward these ideas to legislators and executive councillors? It would appear they are poorly informed or just not interested in this important issue.
J. R. Paine, Tai Hang
Source URL (retrieved on Jul 13th 2013, 10:11am): http://www.scmp.com/comment/letters/article/1281426/letters-editor-july-13-2013
Links:
[1] http://www.scmp.com/news/hong-kong/article/1268769/departure-norm
[2] http://www.scmp.com/comment/letters/article/1271395/incineration-key-managing-waste
[3] http://www.scmp.com/comment/insight-opinion/article/1268244/wading-through-hong-kongs-rubbish-waste-policy
[4] http://programme.rthk.org.hk/rthk/tv/programme.php?name=tv/city_forum&d=2013-06-30&p=899&e=223412&m=episode
[5] http://www.scmp.com/news/hong-kong/article/1263062/lingnan-university-students-threaten-boycott-over-new-pro-government