Emission characteristics of co-combustion of a low calorie and high sulfur-lignite coal and woodchips in a circulating fluidized bed combustor: Part 1. Effect of excess air ratio

WOS: 000327766900090In this study, co-combustion of Bursa-Orhaneli lignite and woodchips mixtures containing 10%, 30% and 50% by wt. of woodchips was studied in a circulating fluidized bed combustor in order to investigate the effect of excess air ratio (k) on the flue gas emissions. The combustor has an inside diameter of 108 mm and a height of 6 m. The temperature of the combustor is kept at 850 degrees C during the combustion tests. During the combustion tests, CO, O-2, NO, and SO2 emissions in the flue gas was continuously measured and recorded by ABB-AO 2000 flue gas analyzer. The results of the tests showed that increasing excess air had a cooling effect on the combustor, but at the same time it also provided smoother temperature profile along the combustor. In order to get minimum flue gas emissions, the optimum excess air ratios for the co-combustion tests of fuel mixture including 10%, 30% and 50% by wt. of woodchips were determined to be 1.18, 1.32 and 1.41, respectively. While woodchips addition to the lignite made CO emissions worse, it did not change NO emission. CO and NO emissions were below the limits but SO2 emission was above the limit for the case of 10% and 30% woodchips co-combustion at optimum excess air ratio. In the case of 50% woodchips co-combustion, SO2 and NO emissions were under the limits but CO emission was a little above the limit at optimum excess air ratio. (C) 2013 Elsevier Ltd. All rights reserved.Turkish Scientific and Technical Research Council-TUBITAKTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [KAMAG-105G023]The financial support provided to this project by the Turkish Scientific and Technical Research Council-TUBITAK (Project Code: KAMAG-105G023) is greatly appreciated

Co-firing of pine chips with Turkish lignites in 750 kWth circulating fluidized bed combustion system

WOS: 000395691900072PubMed ID: 27825549Two Turkish lignites which have different sulfur levels (2-2.9% dry) and ash levels (17-25% dry) were combusted with a Turkish forest red pine chips in a 750 kW-thermal capacity circulating fluidized bed combustor (CFBC) system. The combustion temperature was held at 850 +/- 50 degrees C. Flue gas emissions were measured by Gasmet DX-4000 flue gas analyzer. Two lignites were combusted alone, and then limestone was added to lignites to reduce SO2 emissions. Ca/S = 3 was used. 30% percent of red pine chips were added to the lignites for co-firing experiments without limestone in order to see the biomass effects. The results showed that with limestone addition SO2 concentration was reduced below the limit values for all lignites. CO emissions are high at low excess air ratios, gets lower as the excess air ratio increases. During co-firing experiments the temperature in the freeboard was 100-150 degrees C higher as compared to coal combustion experiments. (C) 2016 Elsevier Ltd. All rights reserved.TUBITAK-KAMAGTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [105G023]The financial support for this project by TUBITAK-KAMAG (Project Code: 105G023) is greatly appreciated. The views expressed in this paper belong to authors