Energy Efficiency with bicarbonate flue gas cleaning process
Waste combustion is not only about getting rid of refuse, but also about getting Energy from Waste, a recovery operation focusing on a high energy output. The SOLVAir® bicarbonate solution, being a simple and dry process, enables to maximize energy efficiency compared to other flue gas treatment processes, thus minimizing CO2 emissions.
Energy efficiency is getting more and more important for the Energy from Waste industry, as cheap fuels becomes rare, CO2 emissions have to be reduced and competition on the waste incineration market increases. In the EC directive on waste 2008/98/EC, an energy efficiency factor 'R1' is defined. If an installation has a factor lower than 0.60 (or 0.65 depending on the permitting date), the operation will not be accepted as 'Energy Recovery' but as 'Disposal'. In some countries Energy Recovery from Waste can also benefit from green energy certificates, as a major part of Municipal Solid Waste (MSW) is renewable biomass, thus boosting profitability.
As showed in the figure below, the energy losses in flue gas have huge potential for improvement.
The SOLVAir® Solution : dry sorbent injection of sodium bicarbonate for flue gas cleaning
As the reactivity of sodium bicarbonate BICAR® is guaranteed for a large moisture content range of the flue gas and temperature window, neither water injection for cooling/conditioning purposes nor reheating of the flue gas upstream of a catalytic DeNOx system (SCR) is needed. This enables to boost energy efficiency by avoiding to use steam or fuel for flue gas reheating.
A German study has established that by using the SOLVAir® bicarbonate process 131 kWh per ton of MSW is available in the flue gas to increase the energy output, which allows incinerators to be classified as Recovery from Waste according the EC Directive (cf above).