Combustion pilot plant

A coal combustion pilot plant is used to obtain efficiency data on the collection of particulate matter by an electrostatics precipitator (ESP). The ESP performance is varied by changing the surface area of the collecting plates. Figure E2.2 shows the data collected to estimate the coefficients in a model to represent efficiency 17 as a function of the specific collection area A, measured as plate area/volumetric flow rate. 

In the example of partial oxidation of methane the highly endothermic reaction of steam reforming of natural gas was combined with the exothermic combustion of methane. Reverse flow operation makes it possible to achieve high temperature in the catalyst bed at a low average difference between outlet and inlet temperatures, thus decreasing the methane consumption for exothermic combustion. Pilot plant tests [32] have demonstrated the feasibility of this concept. 

Fluidized-bedb grained goal Well-stirred combustion Pilot plant 2000-8000 All 0.15-0.6 cm... 

The experiments were carried out in a 1 MWth atmospheric fluidised bed combustion pilot plant, at different operation conditions. Emitted fly ash was collected with an Andersen cyclone cascade system from the stack. The higest concentration of the dangerous PAHs were found on particles having aerodynamic diameter <2.0 pm. The objective of this study, is to expand our knowledge of PAH formation and characterization, emitted in the combustion of a determinate biomass (poplar tree)... 

The experiments were carried out in a 1 MWtb atmospheric fluidised bed combustion pilot plant. 

Four experiments were carried out in the fluidised bed combustion pilot plant with a 16-18 hour test time and whose operation conditions were modified in order to obtain an efficient combustion process. These two conditions yield lower pollutant emissions. Two operation variables were changed mainly in this study feeding rate and air excess percentage. These two parameters, in turn, affect the others parameters. Table 2 shows the combustion operation conditions set in the experiments. In Table 3, the flue gas composition during the four tests is shown. The sampling flue gas temperature was 150 C, the probe, cyclone and filter was all held at the same temperature. The CO level emitted in Test 2 with a 40-60 air excess percentage is lower than in the other experiments. 

Figure 2 Schematic diagram of the recirculating fluidised bed combustion pilot plant. To the left are the feed systems, in the centre are the 0.152 mm square riser, hot cyclone and L-valve return, on the right are flue gas coolers and a baghouse for particulate removal.

This paper demonstrates the technical feasibility of a plastics energy recovery plant using circulating fluidised bed technology from Ahlstrom of Finland. Full details are given of a two-phase test run conducted at Ahlstrom s pilot plant in Karhula, in order to obtain information on the process behaviour when combusting different types of plastics waste. Results are presented and conclusions drawn. 

A semi-industrial pilot plant has been developed in which air-borne ultrasound has been applied to the reduction of particle emissions in coal combustion fumes [62]. The installation basically consists of an acoustic agglomeration chamber with a rectangular cross-section, driven by four high-power and highly directional acoustic transducers operating at 10 and/or 20 kHz, and an electrostatic precipitator (ESP). In the experiments, a fluidised bed coal combustor was used as fume generator with fume flow rates up to about 2000 m /h, gas temperatures of about 150 °C. and mass concentrations in the range 1-5 gm. The acoustic filter reduced fine particle emissions by about 40 %. 

Further optimization of the formation of fullerenes in combustion lead to the development of efficient pilot plants [53-56], Currently, 400 kg of fullerenes per year (Mitsubishi s Frontier Carbon Corporation) are obtained by these methods. 

Azzam, F. 0. and Lee, S., "Design and Operation of Wet Oxidation Mini-Pilot Plant for Complete and Partial Combustion", invited paper for Symposium on The Role of Pilot Plants in Commercialization of Processes, paper No 36E, AIChE Spring National Meeting, New Orleans, LA, Mar 29 - Apr 2,1992. 

Biagini, E., Tognotti, L., Malloggi, S. Pasini, S. 2002. Co-combustion of coal and tire residue in a pilot plant a simplified modelling approach for scale-up predictions of char oxidation. Combustion Science and Technology, 174, 129-150. 

The F EI assumes that a process unit handles a minimum of 5,000 lb or about 600 gal of a flammable, combustible, or reactive material. If less materials is involved (in a pilot plant, for example), the risk will be overstated. 

Large-scale testing in a utility boiler of SRC-II coal distillates from the Ft. Lewis pilot plant indicates complete acceptability in combustion performance and emissions. Testing and development for other applications of SRC-II produced coal liquids is planned, including combustion turbines and medium speed diesels. 

The testing used similar procedures to those described for the laboratory test program. The fuels were blended in tank trucks at the ECLP pilot plant at Baytown, Texas and driven to Charleston, South Carolina. The fuels were loaded hot and remained at an elevated temperature in insulated tank trucks. Fuel temperature for the combustion of the EDS fuels was approximately 43°C. The preheating system was bypassed with the EDS fuels to prevent sediment formation due to incompatibility in the fuel... 

Combustion tests of the bio-oil produced at Metso Power s pilot plant were performed in Fortum s 1.5 MW district heating plant in Masala, Finland [18], In total, approximately 20 tons of bio-oil were combusted during 2010. Not only did the burner perform well, but the bio-oil receiving, storing, and pumping system was reliable despite the fairly low outdoor temperature (-20°C to +10°C) [18],... 

The residual carbon contents at different axial locations of the combustor were measured in the pilot plant tests (Li et al., 1991), as shown in Fig. 18. These data show that axial variations in carbon content with temperature (from 810 °C-923 °C) are as a whole rather slight, but mean carbon content increases with decreasing excess air ratio. Besides, for excess air ratios greater than 1.2, the carbon content at the top of the combustor is somewhat less than that at the bottom, while for excess air ratio less than 1.2, the opposite tendency is evident. In conclusion, for this improved combustor, an excess air ratio of 1.2 is considered enough for carbon burn-out, leading to reduced flue gas and increased heat efficiency as compared to bubbling fluidized bed combustion. That is probably attributable to bubbleless gas-solid contacting for increased mass transfer between gas and solids in the fast fluidized bed, as explained by combustion kinetics. 

---