Carbon from waste should be kept “on the planet”, firm says

As the government reviews its long-term waste strategy, Peter Mills of technology company New Earth Solutions is arguing that keeping MBT residues on the ground acts as a “carbon sink”.

Organic Research Agency is testing New Earth's treatment process for municipal waste with regard to new Environment Agency guidelines

Although the MBT process does emit some carbon dioxide, Mr Mills said much of the organic material within waste can be locked up within stabilised residues.

However, he said incinerating the residue as a refuse-derived fuel – or incinerating mixed waste without any pre-treatment – means virtually all the organic content of waste is turned to carbon dioxide, one of the gases believed to cause global warming.

Sequestration
New Earth Solutions is currently testing its MBT-style process for treating mixed municipal waste with a view to offering it to local authorities across the country.

Contracts director Mr Mills said: “Ideally, our approach is to try to keep the carbon on the planet – it's about carbon sequestration. At the moment, it is portrayed as negative to send it to landfill, but it can also go towards compost for fuel crops or the redevelopment of brownfield land like mines or quarries.

“This is stabilised material – it won't produce methane, it won't produce leachate. You can wash out the heavy metals, but where residues go to engineered landfills, you have no need to do that,” he added.

” At the moment, it is portrayed as negative to send it to landfill, but it can also go towards compost for fuel crops. “
– Peter Mills, New Earth
Mr Mills went on to argue that combustion plants seeking to replace fossil fuels in power generation would be more beneficial burning “carbon neutral” fuel crops. “Waste is seen as carbon neutral, but it still contains materials derived from fossil fuels,” he said.

New Earth
Part of waste firm WH White plc, New Earth Solutions has a 20,000 tonne-capacity plant in Dorset carrying our large-scale trials of treating “black bag” waste from Bournemouth council, through a combination of physical separation techniques and composting.

Independent consultants Organic Resource Agency Ltd have been testing the extent to which New Earth's technology might help meet government-set landfill diversion targets for municipal waste.

At the same time, Worcester-based ORA is effectively providing the first road-test of the Environment Agency's new guidance for MBT residues.

Mr Mills said: “ORA have been using German standards for the testing, but they are now testing new Environment Agency standards – it's an assessment of our technology and how it counts towards biodegradable municipal waste diversion and the Landfill Allowance Trading Scheme.”

Testing
The three major testing procedures being carried out by ORA include the “DR4” respiration test, which measures the stability of residues by analysing its respiration of oxygen. ORA is also a third of the way through testing the Agency's recommended measure of stability – BM100, which is refers to the amount of biological methane that is emitted from the material over 100 days. The ORA testing is also using Loss On Ignition tests, which look into the loss of carbon by burning residues.

Initial results suggest the process will ultimately divert as much as 80% of input municipal waste, Mr Mills said. Previous research from ORA suggested a minimum of 70% diversion would be achieved.

“No one has tried to do a working interpretation of the Environment Agency assessment procedure before,” Mr Mills said. “We are keeping the Agency involved – they need to know whether their guidance is enforceable.”

Mr Mills said for a 50,000 tonne capacity MBT plant – based on a gate fee of under 100 per tonne – testing procedures would most likely cost around 80,000. He said it was a “myth” that MBT had to be a capital-intensive process.