R e p o r t e r : S h e n g Z h a n g S t a t - PowerPoint PPT Presentation

I n f l u e n c e o n c o mb u s t i o n a n d a s h c h a r a c t e r i s t i c s d u r i n g c o - c o mb u s t i o n o f mu n i c i p a l s o l i d wa s t e a n d p e l l e t e d s e wa g e s l u d g e R e p o r t e r : S h e n g Z h a n g S t a t e K e y L a b o r a t o r y o f C l e a n E n e r g y U t i l i z a t i o n , Z h e j i a n g U n i v e r s i t y , C h i n a T e l : + 8 6 - 1 3 1 6 5 9 9 1 6 2 1 , E - ma i l : 1 3 1 6 5 9 9 1 6 2 1 @ 1 6 3 . c o m

CONTENTS 01 Research Background 02 Experiment system 03 Result and discussion 04 Prospect

01 Research Background Landfjll 65% Domestic Contaminant sludge Heavy metal 36 Mt/year Compost Germs, etc. 15% Natural drying Harmless Industrial 6% treatment sludge 38 Mt/year rate Incinerat 32% ion 3% High Sludge Production High Concentration Pollutants Low Harmless treatment rate

01 Research Background Landfjll • Require Large area • Hard to kill germs completely • Fetor • Low cost Incineration Better Option • High rate of volume reduction • Harmless treatment • Recovery energy • High cost

01 Research Background Study target Combustion and ash characteristics during co-combustion of MSW and pelleted sludge in a grate furnace

02 Experiment System Experiment Conditions in the T ube Furnace* Drying Combustion Burn-out Parameter section section section Flow velocity 1.15 4.48 1.22 (m/s) Residence time 18 25 50 (min) T emperature Condition 250 600 450 a(℃ ） T emperature Condition 300 1050 700 *Based on the measured data of a grate furnace in Zhejiang b(℃ ） Province Variables • T emperature conditions • Diameter of pelleted sludge (powder, 3mm and 8mm) • Addition of desulfurizer (CaO, mass ratio: 1%)

02 Experiment System Sludge powder Sludge pellet— Sludge pellet— 3mm 8mm

02 Experiment System • 10g sample (drying sludge ， moisture: 28%) • Section 1, 3 and 5 are used to simulate difgerent combustion conditions (drying, combustion and burn-out) • Bottom ash and fmy ash are collected to get the ratio. • Concentration of fmue gas pollutants is measured online.

03 Result and discussion Condition a Condition b CO 、 NO x 、 SO 2 reaches maximum at combustion section • under all conditions Low concentration of CO and SO 2 appear at drying section • under condition b .

03 Result and discussion • Addition of CaO （ 1% ） in sludge pellets can reduce the average SO 2 concentration in each section. • During the combustion section with the highest SO 2 concentration, the SO 2 concentration at three sections maximum SO 2 removal with/without CaO rate can reach 80%.

03 Result and discussion • With the increase of diameter and compressive strength, the ratio of slag ash and its clinker ignition loss increase, while the ratio of fmy ash decreases. • Under condition a, the clinker ignition loss of slag ash may reach as high as 11.9%. Ash characteristics at difgerent experimental conditions

03 Result and discussion Addition of desulfurizer (CaO) in sludge pellets can reduce SO 2 • emission concentration greatly. • With the increase of diameter and compressive strength, the combustion specifjc surface area of sludge pellets decreases and the fmy ash inside the pellets is hard to escape from it. • Under a low combustion temperature condition (600℃), the clinker ignition loss of slag ash exceeds the limit (5%). • T emperature on combustion section should be higher than 800℃ to avoid incomplete combustion.

04 Prospect Future work 1. Efgect of sludge pellet on ash fusion temperature 2. Co-combustion experiment of sludge and municipal solid waste. 3. Study on crystalline phase and elemental composition of co-combustion of sludge and municipal solid waste by XRD and XRF.

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