Emissions to the atmosphere will be controlled through the use of sophisticated air pollution controls integrated into the MAGS unit and be fully compliant with EPA requirements.
Waste is gasified to produce a solid char and a syngas largely composed of carbon monoxide and hydrogen (and other combustible gases) which are combusted in a separate chamber from the gasifier to produce basically carbon dioxide and water, some acid gases, and residual products of incomplete combustion and particulates.
The hot exhaust is passed underneath the gasifier through a heat exchange zone to reduce the temperature from above 1100oC to about 700oC. It then passes through a venturi scrubber to quickly drop the gas temperature to less than 80oC. This process stops the formation of dioxins and furans but also reduces the acid gases and particulates in the exhaust gases.
The gases then pass through a caustic packed column scrubber where acid gases and particulates are further removed. The final step is for these gases to pass through a condenser to remove water and any entrained residual pollutants or particulates. The clean residual gases are then discharged to the atmosphere at about 30-40oC.
Rainwater collected on site will be used for MAGS operations and for waste heat recovery, generating the hot water needed for bin and facility cleaning and other site uses.
The objective will be to minimise the site’s potable water usage. It is estimated that about 80% of the site’s need can be met through the collection, use and reuse of rainwater.
Some waste waters from the scrubbers containing inorganic salts (mainly sodium chloride) will eventually be generated that will require disposal to the local sewage authority subject to a trade waste agreement.
Waste water from the kitchen and showers will be collected in a grey water system for use on the gardens, while toilet wastes will be discharged to an onsite septic sewage treatment system.
MAGS reduces the mass of the waste by about 90% but instead of producing an alkaline mineral ash with potentially leachable inorganic salts it produces an organic char.
Whereas incineration ash must be disposed of to landfill, and that will probably be in the initial fate of the MAGS char, it is possible for the char to be used as a carbon sequestration agent and soil improver (subject to appropriate testing and regulatory approvals), and research will be undertaken to demonstrate that that this use is feasible and preferable to the landfilling on these residues.
Reduced natural gas use and the generation of a char rather than an ash combine to reduce the production of carbon dioxide by about 50% compared to traditional incineration.
When the current refrigerated storage and transport of clinic and related wastes to Adelaide for incineration is compared with local disposal via MAGs technology the greenhouse gas reduction is even greater. Think global, act local!
The MAGS monitors many parameters through its integrated Data Management System (DMS) to enable it to be a fully automated gasification system. This data and that from the air quality monitors is able to be remotely accessed via the internet and/or a smartphone app enabling operators, management and regulators to access real-time information.