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is ENB doing enough ?

Putrescibles (mostly wet food waste in 2011) 3,994.2 tonnes PER DAY (overall 44.4% of total)

https://www.wastereduction.gov.hk/en/assistancewizard/waste_red_sat.htm

OWTF Phase 1 will treat just 200 tonnes putrescibles per day and Phase 1 + II will treat Max 500 tonnes per day

Wet Food waste (HK wet market wastes have up to 90% moisture content) has a low calorific value (CV) (4 MJ/kg)

For complete combustion (by incineration) at least 6MJ/kg (CV) is required.

http://www.epd.gov.hk/epd/english/environmentinhk/waste/prob_solutions/WFdev_OWTF.html

Organic Waste Treatment Facilities OWTF

Objectives

The OWTF aims to recycle source-separated organic waste generated from the C&I sectors (mostly food waste) to useful products, thereby minimizing requirement for landfill disposal.

Kowloon Bay Pilot Composting Plant and Food Waste Recycling Partnership Scheme

As Hong Kong has little experience in collecting and treating food waste, a Pilot Composting Plant was developed at the Kowloon Bay Waste Recycling Centre in mid 2008 to acquire experience. A Food Waste Recycling Partnership Scheme with the trades and institutions was also established in late 2009 to promote food waste reduction and source separation of unavoidable food waste for subsequent collection and treatment. The Pilot Plant and Partnership Scheme contribute to food waste management and OWTF development in Hong Kong.

Technology

The OWTF would adopt biological technologies – composting and anaerobic digestion (figure below) to stabilize the organic waste and turn it to useful compost products and biogas for energy recovery.

Anaerobic Digestion

Anaerobic Digestion

Benefit

The OWTF will be developed in two phase, where phase 1 would treat 200 tonnes of organic waste (mostly food waste) for the production of biogas and about 20 tonnes of compost every day. The biogas produced in each phase of the OWTF could be used as renewable energy and phase 1 is expected to generate some 14 million kWh of electricity annually (enough for use by 3,000 households in Hong Kong).

The two phases of facilities developed will have a total daily treatment capacity of 400-500 tonnes of organic waste. It is estimated that for the two phases of OWTF, about 28 million kWh of surplus electricity can be supplied to the power grid per year, which is adequate for use by 6,000 households. This renewable energy production will contribute to reduction of 50,000 tonnes per year of Green House Gas emission via reduction in use of fossil fuel for electricity generation. In addition, each phase of the OWTF would avoid landfilling of about 190 and 280 tonnes of waste every day respectively, hence contribute to extending the useful life of landfills in Hong Kong.

Projects

A site search to locate suitable sites for the OWTF was completed. The proposed sites for the first phase and second phase of the OWTF are located at Siu Ho Wan of North Lantau and Shaling at North District respectively.

OWTF location map

The EIA study for developing the first phase of the OWTF at Siu Ho Wan has examined the potential impact of the Project on the environment and the need for mitigation solutions. The Report determined that with the implementation of the mitigation measures proposed by the Project, no unacceptable residual impact is envisaged. The EIA Report was approved by the Director of Environmental Protection on 24 February 2010. The preparation works of the OWTF Phase 1 is in progress.

The Feasibility Study and EIA for the second phase of the OWTF at Shaling were commenced in late 2011.

Artist View of the OWTF

Artist’s Impression of the Organic Waste Treatment Facilities

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