BAN Waste Select Committee evidence

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Phase 1 Day 4 2001-10-08 Chris Whaley and Chris Reynell (Directors, Safe Waste Systems UK)

report from minutes of Select Committee


Submitted: Report on the operation of the above (previously circulated and copy in Official Minute Book)

The Chair welcomed Chris Whaley and Chris Reynell to the meeting.

Mr Reynell made a slide presentation, during which a number of issues were highlighted. Safe-waste Systems had developed the Portagester System, an anaerobic digester combining both liquid and solid digestion in two phases. The first phase utilised simple robust machinery modified to treat solid organic wastes to thermophilic temperatures in three days under anaerobic conditions. The second liquid phase started producing the 60% plus methane rich biogas and would carry on producing gas for a further 30 days. Mr Reynell explained the system in detail. Examples of non-separated household waste were displayed at the meeting. It was noted that costs were kept down because basic industrial agricultural machinery was used in the process.

Chris Whaley reported that his company were committed to the system since they believed in waste as a potential valuable resource, and with the world's resources being used up there was a need to reduce pollution and recover energy. In 'Energy from Waste' (EFW) nitrogen proved a major loss, and the problem with such plants was that if feedstock contained nitrogen, its replacement was only usually achieved by a major input of electricity. Land Network research had revealed the provocative fact that there might be more than 100 million tonnes of waste already collected, dumped or sent to EFW, which could actually be placed on agricultural land. The Portagester operated using the Dobbie process, which was explained to the Select Committee.

Safe-Waste Systems' policy was to provide the best environmentally responsible solution to any waste problem. The system described above complied with Agenda 21 and environmental regulations. The development was supported by the DTI and had won several awards. In energy terms, the Portagester was self-sufficient and was designed to produce a range of effluents with solids contents of up to 40%. The capital costs were lower, and this meant that it opened up a large market.

The benefits of the system were that it was flexible, easy to use, utilised higher temperatures, was faster and more sustainable. Self sufficient, the system produced excellent compost in half the usual time. In terms of end product, the digestate could be spread on farmland or put into windrows. The system's cost were as follows:-

1000 tonnes �60,000
10,000 tonnes �300,000
25,000 tonnes �550,000
40,000 tonnes �950,000

After Mr Whaley and Mr Reynell's presentation, the following questions were asked:-

(1) Are you aware of any government plans to support the development of newer or alternative technologies, such as anaerobic digestion? (Bob Stewart)

Mr Whaley stated that there had been discussion at Government level, and there could well be developments, but this was uncertain. The tendency had been more towards EFW in the past. In response to Bob's query on how Newcastle City Council could assist, Mr Whaley stated that his company were ready for discussion. Bob then queried whether EFW via incineration used more energy than was actually produced. Mr Whaley reported that in fertiliser terms, this was certainly the case. Up to seven times the amount of electricity was required to make up the nitrogen. Mr Hale undertook to provide research material undertaken by Hull University. He wished that more University work was taken seriously by the government. Mr Whaley suggested that if plastic was used as an aggregate, its use as a replacement for concrete etc could be extensive. (Examples of material produced by his process, were displayed at the meeting). Reference was also made to the use of such material which had a 'wood' aspect, but which could not rot. (This material had been used in the building of flood barriers etc)

Bob Stewart queried the extent of additional costs once a Portagester had been purchased. Mr Whaley stated that this mainly related to the cost of a worker. In the sense that payment was already being made for use of landfill, there was an 'offset' cost here. In terms of heat, the engine was using its own.

(2) What do you do with your product when it's been through the Portagester system? (Eric Landau)

Mr Whaley stated that the material went back onto farmland, if the original source was livestock. This would not be sold to farmers; rather they could be paid �5/�10 per tonne to receive, store or spread.

(3) How can markets for compost be developed? (June Wolf)

Mr Whaley made reference to the fact that in Hampshire, a large food company had developed a farm 'village', and had purchased a Portagester for use there. However, initial support from the local authority had been withdrawn. It was believed that this was because waste was required to keep incinerators profitable.

In responding to a query on sewage sludge contamination, Mr Whaley stated that heavy metals came from what was added to such sludge via the water system and then dumped into the sea. Heavy metals in fermentation ended up being washed out. The Chair queried whether the sample 'brick' displayed at the meeting still contained heavy metals. Mr Whaley suggested that this was 50% below the original composition.

Phil Capon queried whether difficulties arose because the system hadn't been used on a large scale, and that it required local authorities to make investments in large-scale schemes. Mr Whaley suggested that funding was not so much the problem; rather, the company would like to acquire a site.

Val Barton expressed concern at the situation concerning heavy metals, and queried whether Safe-Waste was suggesting separation at source. Mr Whaley circulated an additional paper at the meeting (copy in Official Minute Book) and confirmed that separate collection was preferred. Whereas local authorities regarded this as too expensive, he suggested that this would not be the case if the Portagester system were used. Indeed, savings could be made.

Roger Mould queried who the system's potential customers were in the absence of local authority funding. Mr Whaley suggested that this could be the agricultural industry, water companies, breweries, zoos or large food companies. All such potential customers would save money.

The Chair made reference to the scenario in Greater Manchester, where the view had been expressed that such material was only suitable for the top of landfill. Also, substantial composting had been undertaken in Cheshire, where difficulties had been experienced in disposing of it. Mr Whaley suggested that �5/10 per tonne was an inexpensive method of treatment. The Chair queried if such a process was environmentally sound. Shouldn't the material be sent back where it came from rather than it being put back on the land? Mr Whaley made reference to the situation in Peterborough, where land was a metre below sea level. Land mass was actually decreasing, with topsoil being lost due to erosion. There was therefore a need to replace it. There was also a need to recognise that the farming industry was in depression at present. The Chair queried whether Safe-Waste was confirming that so long as there was separation at household level, then it could produce satisfactory material for farmland. Mr Whaley confirmed this statement.

The Chair thanked Mr Whaley and Mr Reynell for their attendance.