Proceedings World Bioenergy 2010

More documents

Recommendations

Info

[15] Fernández Llorente M.J., Murillo J.M., Escalada R., Carrasco J.E. Ash behaviour of lignocellulosic biomass in bubbling fluidised bed combustion. Fuel 85 (2006) 1157- 1165. [16] Fernández Llorente M. J., Borjabad E., Barro R., Losada J., Bados R., Ramos R., Carrasco J. E. 2007. Estudio sobre sinterización de las cenizas de biomasas en la combustión. CIEMAT. [17] Fernández Llorente M.J., Escalada R., Murillo J.M., Carrasco J.E. Combustion in bubbling fluidised bed with bed material of limestone to reduce the biomass ash agglomeration and sintering. Fuel 85 (2006) 2081-2092. [18] Zevenhoven-Onderwater, M., Blomquist, J.-P., Skrifvars, B.-J., Backman, R., Hupa, M. The prediction of ehaviour of ashes from five different solid fuels in fluidised bed combustion. Fuel 79 (2000) 1353–1361 [19] Werther J., Saenger M., Hartge E.-U., Ogada T., Siagi Z. Combustion of agricultural residues. Progress in Energy and Combustion Science 26 (2000) 1–27. [20] Arvelakis, S., Vourliotis, P., Kakaras, E., Koukios, E. G. Effect of leaching on the ash behavior of wheat straw and olive residue during fluidized bed combustion. Biomass and Bioenergy (2001) 20(6) 459-470 16 world bioenergy 2010
IMPROVED FLEXIBILITY AND ECONOMY BY USING SMALL FLUIDISED BED BOILERS IN DISTRICT HEATING Alpo Sund 1 , Matti Lilja 2 1 Nurmijärven Sähkö Oy, Kauppanummentie 1, 01900 Nurmijärvi, Finland 2 Renewa Oy, Teknobulevardi 3, 01530 Vantaa, Finland matti.lilja@renewa.fi ABSTRACT: The Finnish heating company Nurmijärven Sähkö generates annually over 80 GWh heat with wood based fuels. To ensure optimal flexibility and minimal emissions, company has chosen fluidised bed combustion for two of its below 12 MW heating plants. These plants have shown a capability to operate at very low partial loads during low demand seasons, thus reducing the need to use oil fired reserve boilers. Exploiting of lower cost fuels, like slash from local forests, has been possible due to the flexible combustion process. Emissions have been successfully kept clearly below set limits, also at partial load operation or when using variable quality of fuels. Keywords: fluidised bed, heat generation, district heating, operating experience 1 INTRODUCTION Nurmijärven Sähkö Oy is a municipality owned energy service company in Southernmost Finland. It provides 9500 inhabitants with 90 GWh heat annually. About 95 % of the heat is generated with wood based fuels in company’s three plants. This equals to 120 000 cubic meters of wood. To ensure economical heat for its customers, Nurmijärven Sähkö needs heat generation with is flexible to meet fluctuating heat demands, as well as digest versatile fuel and take the advantage of lower priced slash or waste wood batches from near-‐by sources. In order to be able to maximise the operational flexibility, the company has chosen bubbling fluidised bed (BFB) combustion for two of its heating plant. The 8 MWth and 11 MWth units have been operated since 2002 and 2007. The units are normally unmanned and controlled remotely. 2 COMBUSTION TECHNOLOGY Heating plants in the localities Nurmijärvi and Rajamäki have a capacity of 8 MW th and 11 MW th, respectively. Their combustion system is based on bubbling fluidised bed technology, where the fuel is introduced in the furnace where a 4 ton sand bed and the primary combustion air form a homogenous mixture with about 800 o C of temperature. The furnace and fluidized bed with the boiler form an integrated structure which is completely enclosed in a water cooled structure. There are refractories on the side walls in order to achieve correct combustion temperature and to prevent erosion. The boiler has a fully welded hermetic structure of membrane walls. The furnace is in the shape of rectangle. The structure is self-supporting and propped up from below which allows thermal expansion upwards. Because only few kilos of fuels are in the furnace at each moment, the gasification and combustion is fast. The heat capacity of the sand is so big that any amount of fuel humidity is easily evaporated and doesn’t harm the combustion itself. Fluidized bed temperature is controlled by combustion air distribution to primary, secondary and tertiary air. The well controlled furnace temperature is important for minimising of the temperature-derived NOx creation. With dry fuels, when the fluidized bed temperature might otherwise become too high, circulating gas is used in the fluidising air system. Figure 1. Hot water boiler with a Renewa bubbling fluidised bed Fluidised bed combustion is better known for utility world bioenergy 2010 17
Page 1 and 2: MaIN spONsOR: WORLD BIOENERGY 2010
Page 3 and 4: ORGaNIsED BY: The swedish Bioenergy
Page 5 and 6: a B C CONTENTs OpENING sEssION 7 Bi
Page 7 and 8: OpENING sEssION world bioenergy 201
Page 9 and 10: The black curve is what actually ha
Page 11 and 12: a COMBINED hEaT aND pOWER (Chp), CO
Page 13 and 14: Chlorine Index: Cl content (%) of t
Page 15: The DOMOHEAT European project is fo
Page 19 and 20: plant, is permanently manned. Rajam
Page 21 and 22: PROCUREMENT COSTS OF SLASH AND STUM
Page 23 and 24: Figure 2: Marginal cost curves for
Page 25 and 26: HARVESTING FOR ENERGY OR PULPWOOD I
Page 27 and 28: Figure 1: The net income as functio
Page 29 and 30: CO 2-EQ EMISSIONS OF FOREST CHIP PR
Page 31 and 32: Figure 4: CO 2-eq emissions (kg/m 3
Page 33 and 34: [27] Wihersaari, M. 2005. Greenhous
Page 35 and 36: modes suitable for longer distances
Page 37 and 38: Figure 4: End users’ market share
Page 39 and 40: Table I: Annual capacity of vehicle
Page 41 and 42: comminuted biomass, as is stable gr
Page 43 and 44: BIOMASS FUNCTIONS FOR YOUNG SCOTS P
Page 45 and 46: 2). In the data for branches and fo
Page 47 and 48: ESTIMATING POTENTIALS OF SOLID WOOD
Page 49 and 50: 3.2 Techno-economical potential Whe
Page 51 and 52: C pOLICY - hOW TO MaKE IT aLL happE
Page 53 and 54: of the best (if not the best) way t
Page 55 and 56: 1, nº 1(Jul/Dez.1996)-Rio de janei
Page 57 and 58: consortiums of people) do not have
Page 59 and 60: BIOENERGY IN UKRAINE: STATE OF THE
Page 61 and 62: Ukraine till 2015 can be suggested
Page 63 and 64: ioenergy industry. The Climate Cons
Page 65 and 66: SUPPLY CHAINS OF FOREST CHIP PRODUC
Page 67 and 68:
stump wood batches were also commin
Page 69 and 70:
INSTRUCTIONS FOR PREPARATION OF PAP
Page 71 and 72:
Pakistan’s reserves. Pakistani bu
Page 73 and 74:
distributors in Pakistan, and the r
Page 75 and 76:
other sources of energy, it is impe
Page 77 and 78:
http://www.nation.com.pk/pakistan-n
Page 79 and 80:
BIOGAS UPGRADING BY TEMPERATURE SWI
Page 81 and 82:
into the adsorber (more information
Page 83 and 84:
Once again, the binary gas mixture
Page 85 and 86:
EMISSIONS CHARACTERISTICS OF A RESI
Page 87 and 88:
Figure 3: Accumulated emissions fro
Page 89 and 90:
NEW INSIGHTS IN THE ASH MELTING BEH
Page 91 and 92:
Figure 4: Statistical analyses (lin
Page 93 and 94:
f ENERGY CROps, aGRICuLTuRaL REsIDu
Page 95 and 96:
INTERCROPPING OF REED CANARY GRASS,
Page 97 and 98:
5. ACKNOWLEDGEMENTS This project wa
Page 99 and 100:
form of heat and constitutes 0.65%
Page 101 and 102:
II BOILER CHARACTERISTICS Capacity,
Page 103 and 104:
some optimisation in local employme
Page 105 and 106:
local straw production for fuel sal
Page 107 and 108:
Secondary School]. (2009). 58. Bela
Page 109 and 110:
CONfERENCE TuEsDaY 25 MaY 09.00 OpE
Page 111 and 112:
CONfERENCE ThuRsDaY 27 MaY 09.00 pa
Page 113:
TaKING YOu fROM KNOW-hOW TO shOW-hO
show all

Proceedings World Bioenergy 2010

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?