Thursday 24 August 2017

The Age of Steam?

DOUG COLLIE reports on a radical move to solve the deepening Borders waste crisis

The repeated failure of the so-called NEAT system of incineration at the research and development stage meant that by early 2014 the planned £23 million waste treatment facility for Scottish Borders to deal with up to 40,000 tonnes of municipal rubbish was already years behind schedule.

A newly released file of around 80 documents linked to the disastrous contract between Scottish Borders Council and waste management company New Earth Solutions Group has provided detailed information concerning the test failures which frustrated the Borders project throughout its existence.

Our recent series of articles has attempted to give readers an idea of how far NESG engineers were from perfecting the Advanced Thermal Treatment (ATT) system which was to be installed in the plant at Easter Langlee, Galashiels.

Yet another failed test is chronicled in a report from July 2014. Those involved in the project had already been given the devastating news of a further two year delay thanks to the technological hitches coupled with a lack of financial backing for the gas-based pyrolysis method of converting refuse into electricity.

The technical report on the July event says: "An extended trial began in the evening of 6th July. Unfortunately the trial had to be stopped in the afternoon of 7th July due to a significant pressure drop across the pyrolyser. Initial investigations suggest that a problem has occurred with the char (ash) extraction.

"The fuel used in the trial was a 60/40 blend of oversize and biofines and the feed rate was 1 tonne/hour. This is a different mix to that previously used but very comparable to the fuel specification for Easter Langlee. It is considered that a greater quantity of char is produced from this fuel specification and coupled with a high feed rate this has led to a build-up of char in the pyrolyser and consequently the pressure drop experienced. Further investigations are being carried out to confirm if this is the case."

A leading member of the project team commented in an email:“This again is worrying.  It has taken 1 year and 8 months since the DoV (the fateful Deed of Variation signed by councillors in October 2012 and implemented in December 2012) to run fuel representative of Easter Langlee and it caused problems!”

However, help was at hand. Within a month NESG, which had provided a long string of reasons and excuses for delays with technology and funding, suddenly came up with another massive contract revision to solve Easter Langlee's woes.

An email from top brass at New Earth HQ to SBC set out the solution in detail. The message explained: "As you are aware the Easter Langlee project has always been based on small scale energy generation using gas to engine technology. 

"With the experience we have gained at Avonmouth (the NESG plant near Bristol) we now consider a steam based project to be potentially viable. In part this has been aided because the original regulatory permit requirements of SEPA preferred a gas to engine solution to a steam solution. During the intervening period SEPA has relaxed these regulations to the point that a steam solution like that in use at Avonmouth appears more possible. To this end, the NESG team are doing a review of the viability of delivering a steam solution to Scottish Borders."

Such a major switch in technology would require a wide-reaching project review, and some of the points for discussion are set out in the document. We reproduce the text in full:

 Scale – Because of the inclusion of the boiler and other ancillary equipment the steam system takes up more space so we need to identify if we can accommodate it / what additional space would be needed and the implications on planning and permitting.

 Affordability – Again because of the boiler the capital cost of this solution is higher. We are looking to see if the solution can be tailored to meet the requirements of the Scottish Borders volumes.


 Third party volumes – It may be that a steam solution is only viable at a minimum of 9-10 units which equates to 70-80 thousand tonnes of RDF per annum (double the volume of rubbish generated in Scottish Borders). 

For this reason we will need to discuss with you any issues arising from bringing other parties material into the site. We also need to understand if this material is available. Clearly if we can provide a steam solution it would enable us to speed up the project because we would no longer be waiting on the Canford R&D development timetable and the funding for this solution would be more readily available.

And with the Borders scheme so far behind schedule, NESG even had a short-term sweetener on offer to deal with household rubbish until the steam engine arrived in the Easter Langlee "siding".

The email continued: " Interim residual waste treatment solution – In recognition that the project has been delayed, NESG is currently reviewing the availability of emerging treatment capacity in the North East of England. 

"This could result in New Earth offering the Council an interim treatment solution for all or part of its residual waste, which could be transferred from the Council’s transfer stations to a third party treatment facility, pending the development of the Easter Langlee treatment facility. Clearly we would appreciate your early feedback to this concept as we understand that you will have engineered void at Easter Langlee landfill and also landfill gas generation income. However, this potential opportunity may offer the Council an interim recycling and landfill diversion benefit."

How ironic: a proposal hatched in 2014 to transport local refuse in fleets of lorries for treatment elsewhere turns out to be the preferred option in 2017...if planning permission can be secured for a waste transfer station on the same site where a conventional treatment facility should have been functioning FOUR years ago. A glittering example of bungling incompetence?

NEXT: THE REACTION TO THE STEAM OPTION

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