Co-combustion of Lignite with Biochar

Transcription

1 Co-combustion of Lignite with Jale Yanik, Asli Toptas, Yeliz Yildirim Department of Chemistry, Faculty of Science, Ege University, 351 Izmir,Turkey

2 General Aspects Aim Materials and Methods Results Conclusion

3 What is? Solid product from thermochemical processing of biomass Agro wastes Forest wastes Industrial wastes Animal wastes

4 What is? lower amount of volatile organic compounds (VOCs), no water, they can be stored for many years without decay. The higher energy density allows savings on transport and storage compared to ordinary biomass pellets. Biohar is higher in BTU values than white pellets with nearly identical physical qualities as coal thereby creating a value-added product

5 What is? production

6 Aim a solution for environmental problems related to - wastes from agriculture and poultry farms - greenhouse gas emissions from coalbased power plants. Combustion behavior various raw/torrefied biomasses and their blends with a Turkish lignite were investigated by TG analysis.

7 MATERIALS Vine stem Olive stem Corn stalk Broiler litter Laying hens litter Proximate analysis (wt%) Moisture Ash Ultimate analysis (dry wt%) C H N S O broiler litter: poultry excreta, spilled feed, feathers, and bedding materials (straw, sawdust, etc.) laying hens litter: poultry excreta

8 Ash Composition, wt % Fe 2 O 3 Na 2 O K 2 O MnO MgO CaO Al 2 O 3 SiO 2 LHL BL OS VS CS Lignite

9 Composition of lignocellulosic material (wt%) Vine stem Olive stem Corn stalk Cellulose Hemicellulose Lignin Extractives

10 Fixed bed reactor (V: 1 L) yield, % = (mass of char / mass of biomass (db)) * 1 Energy densification = HHV of biochar /HHV of biomass Heating rate: 5 C/min Pyrolysis temp : C/min Holding time: 1 h N2 flow: 25 ml/min. Feed: 1 g Energy yield, % = biochar yield * energy densification

11 Combustion Experiments Thermogravimetric Analysis (TGA) Experimental conditions; Heating rate: 2 C /min Combustion atmosphere: Air Air flow: 1 ml / min Sample amount: 3 mg

12 Combustion Experiments char burning dewatering volatilization and burning burnout,

13 Data Analysis I, ignition temperature B, burnout temperature, the rate of weight loss become <1 wt.%/ min M, highest dm/dt value Reactivity = 1 x maximum combustion rate / peak temperature Wang C, et al., Thermogravimetric studies of the behavior of wheat straw with added coal during combustion Biomass and Bioenergy 29, 33(1), 5-56.

14 Yield yield, %

15 1, 9, 8, 7, 6, 5, 4, 3, 2, 1,, Co-combustion of Lignite with Elemental Analysis of 1, 25 C 9, 3 C 38,7 3, 36,8 27,1 O 8, 21,1 33,2 2,8 19,1 S 7, 2,3 5,5 33, 4,2 1,2 1,1 4,3 5,9 1, 5, 4,9 1,3 N 6, 1,6 5,5 27,5 4,4 5,2 5, H 5, 4,3 3,2 C 4, 6,4 2,6 52,4 57,9 3, 62,4 65, 5,8 52,3 55,2 57,4 37,2 2, 36,6 1,, CS OS VS LHL BL CS OS VS LHL BL 1, 9, 17,3 8,,1 7, 4,5 3,7 6, 5,,1 2,4 4, 69,3 3, 2, 45,6 35 C 18,9,4 4,5 64,7 1,, CS OS VS LHL BL 17,9,2 O 29,7 3,9 S,2 2,6 N H 57, C 37,4

16 Fuel properties of biochars and lignite CS OS VS LHL BL lignite Ultimate Analysis, wt %(db) S Proximate Analysis, wt % (db) VM FC Ash HHV b, MJ kg

17 2, 1,8 1,6 1,4 Biomass OS VS BL LHL CS H/C atomic ratio 1,2 1,,8,6 lignite T-BL bitumious coal T-CS T-VS T-OS T- LHL,4,2 antracite,,,1,2,3,4,5,6,7,8,9 1, 1,1 1,2 1,3 1,4 1,5 1,6 O/ C atomic ratio

18 Energy Densifications Energy Yields , ,5 8 1, CS OS VS LHL BL CS OS VS LHL BL

19 biomass biochar Vine Stem Olive Stem Corn Stalk 9 8 biochar biomass Laying hens litter Broiler litter

20 blend LHL blend LHL BL Lignite BL Lignite Blend: 5 % lignite + 5 % chicken litter

21 blend 14 lignite 12 OS 1 VS CS dtg lignite OS VS CS Blend: 5 % lignite + 5 % lignocellulosic biomass (OS+VS+CS)

22 Blend: 5 % lignite + 5 % wastes (lignocellulosic + litter)

23 Combustion Characteristics of Wastes and s Ignitation Temp. ºC Burnout Temp. ºC Olive Stem Vine Stem Corn Stalk Laying Litter Broiler Litter raw char raw char raw char raw char raw char T max, ºC Reactivity

24 Combustion Characteristics of Blends and Lignite Ignitation Temp. ºC Burnout Temp. ºC Lignite Blend 1 Blend 2 Blend T max, ºC Reactivity Blend 1: 5 % lignite + 5 % chicken litter chars Blend 2: 5 % lignite + 5 % lignocellulosic biomass chars (OS+VS+CS) Blend 3: 5 % lignite + 5 % chars derived wastes (lignocellulosic + litter)

25 CONCLUSION Torrefaction moves the chemical and physical properties of lignocellulosic biomass and poultry litters close to that of lignite. Although biochars are more reactive than lignite, reactivity of blends similar to or less than that of lignite. Ignition and burnout temperatures of blends are lower than that of lignite.

26 CONCLUSION The effect of biochar on the combustion characteristics of blend varied with kind of torrefied wastes; biochars from poultry litter led to decrease in reactivity, whereas biochars from lignocellulosic biomass led to more decrease in ignition and burnout temperatures.