# Flue Gas Composition and Treatment Potential of a Waste Incineration Plant
## 3 Results
### Adopted Flue Gas Cleaning System for the Proposed Plant
It should be noted that before the obligated abatement stated by the IPCC, the Kyoto Protocol, and other agreements, laws, and regulations issued to reduce the amount of CO\({}_{2}\) emissions, which make a direct contribution to climate change, this amount of pollution (CO\({}_{2}\) emissions) was directly released into the atmosphere. All European countries and those that have waste incineration techniques are now issuing regulations to reduce the amount of emissions from or with flue gas. For example, the waste incineration plant in Oslo in Norway (klemestrud) was the source of 385,000 tons of CO\({}_{2}\) emissions each year, and therefore, Oslo's goal of a 95% reduction in emissions by 2030 is necessary [38]. A successful pilot project in 2011 to capture 90% of the CO\({}_{2}\) from a small flue gas stream is now a full-scale carbon capture project [38]. The project will capture 400,000 tons of CO\({}_{2}\) every year in an amine-based absorption capture plant. Although this is an early example of large-scale capture of WtE, the capture process is well understood and has been tested in other capture applications [39]. According to the simulation results, 9.4 kg/s of spherical carbon was required to verify 91% of CO\({}_{2}\) reduction (as shown in Table 13). This means the equivalent CO\({}_{2}\) for each ton of waste is to be reduced to 0.03 tons for each ton of waste. The results of the model calculations for CO\({}_{2}\) and O\({}_{2}\) were validated by comparing them with Epsilon's results and the available data from the literature which were adapted from real incineration plants. The model is viable to be used in the design phase and to predict the amount or percentage of CO\({}_{2}\) emissions in the generated volumetric flue gas. An integrated flue gas cleaning system was also simulated in this study. The results depended on an elementary analysis of the data which was prepared to build a comprehensive model (simulated) of a waste incineration plant with its related emission cleaning system. The proposed cleaning system for flue gas starts with SNCR to control and reduce the emission of NO\({}_{2}\) and ends with the reduction process for CO\({}_{2}\). The model is illustrated in Figure 8.  
Five points were made on the stream line of the flue gas to illustrate the important stages that the flue gas passes through during the cleaning process (see Figure 8). The heat exchangers 1 and 2 have the same role as the boiler in the simulated facility. Point 1 is the effluent from the combustion chamber where the flue gas holds the total amount of thermal energy and the whole volume of gas emissions. Point 2 gives the data for the flue gas emissions just after the SNCR to scale-up the NO\({}_{2}\). Point 3 is after the first heat exchanger (the first stage of the boiler) and electrostatic precipitator (which works to reduce the amount of the particulate matters in the flue gas). Point 4 is after lime injection to measure the reduction in SO\({}_{2}\) and HCl. Point 5 is the most important, and comes after the injection of carbon (spherical carbon material) to capture CO\({}_{2}\) and reduce its concentration in the flue gas stream. Splitter is a component of Epsilon which is used to separate compounds and materials. Two different mass flowrates of MSW (25 and 30 kg/s) were inserted in the simulated model of the cleaning system. This produced the same emission values for both mass flowrates loaded into the furnace, and as they were the same, only the results for the 25 kg/s MSW are presented in Table 14. The effect of excess air was clear, as shown in Figure 9. For CO\({}_{2}\) emissions at 1.5 excess air ratio, the first value for the CO\({}_{2}\) concentration emitted from the furnace was 258,514 mg/Nm\({}^{3}\) which could be reduced to 6000 mg/Nm\({}^{3}\) before the stack. To achieve this reduction, around 9.4 kg/s of spherical carbon should be injected.