Mary Melville is spot on with her comments on food waste and her invitation to the secretary for the environment (“Environment-friendly fix makes molehill of food waste mountain [1]”, October 12).
Besides the possibility of using special bacteria to convert biosolids sludge into agricultural fertiliser, there is a similar biological system (operational in California) that converts such waste into bio- plastics. It is reported that these biodegradable materials offer a realistic alternative to plastics derived from oil – seemingly a double whammy for environmentalists.
Many lucid letters have questioned the Environmental Protection Department’s plan for a massive incinerator at Shek Kwu Chau and its brusque brush-off of Green Island Cement’s efforts to use municipal solid waste (MSW) in an Eco-co-combustion facility proposed at its Tap Shek Kok cement plant.
Elvis W. K. Au, assistant director of environmental protection, poured cold water on this proposal because “this technology has not been used for MSW treatment anywhere in the world for large tonnages” (“Cement plan not yet viable refuse solution”, August 16).
I was therefore astounded to read the report (“Saving a packet”, October 2) about a firm that has been highly successful in using this technology on a large scale in Switzerland for some time and will incorporate the technology into its Asian cement kilns in India and Vietnam.
It seems that our Environmental Protection Department is getting well behind the curve. Cement kilns operate at 1,450 degrees Celsius and gasification plants burn at over 1,500 degrees, whereas the outdated incinerator planned for Shek Kwu Chau will only reach 850 degrees.
This has a large bearing on emissions and residue.
I also cannot understand why we are not planning to use already proven plasma gasification technology to generate electricity from MSW, in conjunction with Hongkong Electric and CLP Power. This would render the Shek Kwu Chau plans superfluous.
It appears our civil servants are bureaucratically locked into a plan that will not give Hong Kong the most effective, efficient, or environmentally sound outcome, and therefore the Legislative Council was correct to block the department’s funding request. By Mr Au’s own admission, the department has blocked Green Island Cement’s use of MSW since 2000, while all this time our landfills inexorably extend.
Perhaps when environment secretary Wong Kam-sing replies to Mary Melville, he can also clarify the confusion surrounding the Shek Kwu Chau project.
24 Oct 2013