A 5 week trial of two PyroPure PP4 units was conducted in a 15 storey block of flats in the London Borough of Wandsworth from 1 September 2009 to 4 October 2009. The trial demonstrated that the PyroPure technology is suitable for the destruction of municipal waste in high rise apartment blocks.
The purpose of the trial was
- To prove that the units were capable of dealing with the volume of waste generated by the residents of a 15 storey buildings containing some 56 flats.
- To show that the operation of the units did not prove to be a problem to any of the residents by reason of smell, noise or anything else which a resident might construe as being a nuisance.
- To show that the emissions would not be harmful either to the residents or to the environment.
Two prototype PyroPure PP4 units were situated in the waste chamber which is in the basement of the building. There is a waste chute which extends to the full height of the building and residents can put their rubbish down the chute on every floor. The chute entry point is not large: it will take a full supermarket carrier bag but not a black plastic bag. The PyroPure waste handling system was positioned beneath the chute so that rubbish coming down the chute entered the system and was then transported to an available PyroPure chamber. The process repeated until 6 loads had been dumped. Once the chamber was full the lid closed and the destruction cycle started. The waste handling system then transported waste to the second unit until it was full.
The trial confirmed that
- the units were able to deal with the waste that is generated
- the residents of the building had no issues with the installation
- the gaseous emissions were minimal and the levels were not harmful
The waste handling system worked and dealt with the waste in the correct manner, but the trial revealed that a simpler system based on a slightly different principal involving some short term (less than 6 hours) storage of waste in a hopper above the unit(s) would be preferable.
The main conclusions from the trial can be summarised as follows:-
- A single unit is capable of handling the waste that is deposited down the waste chute
- An additional unit will be required to handle the waste deposited in the outside bins
- The operation of the units was not regarded as a nuisance by any resident and no complaints were received
- With the exception of oversized, overweight items the units can deal with all the waste that is generated. Pre-sorting of waste such as metal, glass and ceramics would not be required, although it would be beneficial as the units would be more efficient if the residents were encouraged not to put glass, metal or ceramics down the chutes
- Discharge of the ash residue to the sewer worked well and did not cause a blockage
- The gaseous emissions were minimal and would not harm personnel or the environment
- Cycle times, electrical energy consumption and water usage were higher than early predictions but these were prototype units operating for the first time in a ‘real’ environment and the PyroPure PP5 system uses significantly less water and electricity.
- All technical problems were successfully dealt with on site within 24 hours.
- Cat litter does not present a problem for the process itself but it quickly builds up in the basket and lengthens cycle time and power consumption if not removed. Residents could be asked to avoid depositing cat litter into the waste chutes.