Ammonia scrubbing technology for CO 2. capture. Wang Shujuan Department of Thermal Engineering Tsinghua University May 24, 2007

Transcription

1 Ammonia scrubbing technology for CO 2 capture Wang Shujuan Department of Thermal Engineering Tsinghua University May 24, 2007

2 Our group-ecane Prof. Xuchang Xu Prof. Changhe Chen Yan Li Yuqun Zhuo Huiling Tong Shujuan Wang

3 Outline Introduction Ammonia Scrubbing: general Ammonia Scrubbing: Tsinghua University Solar energy used for CO 2 capture Conclusions

4 Introduction: primary energy consumption of China (Mtce) coal oi l NG ot her s : low increasing of energy consumption due to decreasing proportion of secondary industry :accelerating increasing of energy consumption due to the light industry expansion :energy consumption increasing fluctuation :acceleating increasing of energy consumption

5 Introduction Primary energy consumption mix Main indicators comparison Chi na 2005 Wor l d coal oi l NG ot her s per cent age i n wor l d t ot al ( %) popul at i on GDP Ener gy Car bon OECD Chi na

6 Introduction

7 Ammonia scrubbing technology: general CO 2 + NH 3 + H 2 O NH 4 HCO 3 CO 2 + NH 3 NH 2 COONH 4 NH 2 COONH 4 + H 2 O NH 4 HCO 3 + NH 3 NH 3 + H 2 O NH 4 OH NH 4 HCO 3 + NH 4 OH (NH 4 ) 2 CO 3 + H 2 O (NH 4 ) 2 CO 3 +CO 2 + H 2 O 2NH 4 HCO 3 2NH 4 HCO 3 (NH 4 ) 2 CO 3 +CO 2 + H 2 O NH 4 HCO 3 CO 2 + NH 3 + H 2 O (NH 4 ) 2 CO CO NH 3 + H 2 O

8 Ammonia scrubbing technology: general Comparing with MEA Loading capacity NH 3 : 1kgCO 2 /kg NH 3 MEA: 0.35kgCO 2 /kg MEA Removal efficiency NH 3 : 99% MEA: 94% Byproducts recoverability NH 3 : easy MEA: difficult

9 Ammonia scrubbing technology: general Economic assessment by NETL

10 Ammonia scrubbing technology: Tsinghua experimental setup 1 Semi-batch reactor

11 Ammonia scrubbing technology: Tsinghua experimental setup 1

12 Ammonia scrubbing technology: Tsinghua experimental setup 2 Continuous reactor

13 Ammonia scrubbing technology: Tsinghua experimental setup 2

14 Ammonia scrubbing technology: Tsinghua experimental setup 2 Heated lines exhaust On-line analyzer Temperature controller Mixing Vessel Water SO 2 absorption reactor CO 2 absorption reactor NH 3 + H 2 O Pump SO 2 CO 2 N 2 NH 3 Constant water bath Products humidifier Combined removal of CO 2 /SO 2

15 Ammonia scrubbing technology: Tsinghua Experimental results CO 2 removal efficiency as a function of the reaction time CO 2 concentration /ppm % CO 2 removal efficiency CO 2 removal efficiency time /min 0.0 CO 2 removal efficiency NH operation tem perature ( 0 C) CO 2 removal efficiency as a function of the reaction temperature

16 CO2 removal efficiency as a function of reaction time for various ammonia solution concentrations. The operating conditions were at CO 2 inlet concentration of 12%(v/v), water bath temperature of 28 CO2 removal efficiency as a function of reaction time for various CO 2 concentrations. The operating conditions were at CO 2 inlet concentration of 10% 12% 14% (v/v), water bath temperature of 28, and ammonia concentration of 0.140mol/l.

17 CO 2, SO 2 removal efficiency as a function of reaction time. Operation conditions: temp. of water bath 45, temp. of water steam 50 Concentration of SO 2 is 3000ppm, concentration of CO 2 is 10% CO 2, SO 2 removal efficiency as a function of reaction time. Operation conditions: temp. of water bath 55, temp. of water steam 50 Concentration of SO 2 is 2500ppm, concentration of CO 2 is 12%

18 Ammonia scrubbing technology: Tsinghua Life Cycle CO 2 Emissions Combined System Separated System 0.78Mt 1.01Mt 0.64Mt 1.22t/tNH Mt 5% 95% 2.87Mt kwh CO kwh 0.08Mt 0.3Mt 1.16Mt /year 1.68Mt 2.69Mt/year

19 Ammonia scrubbing technology: Tsinghua System Simulation Absorption Column Aspen Plus TM unit: RADFRAC 10 equilibrium stages No condenser or roboiler Desorber Column Aspen Plus TM unit: RADFRAC 2 equilibrium stages No condenser Reboiler: Kettle Adopted Property ELECNRTL

20 Ammonia scrubbing technology: Tsinghua System Simulation

21 NH3 amount i n gas l eavi ng absor ber [ kmol / hr ] Absor ber pr essur e [ at m] Fl ow r at e [ kmol / hr ] Absor ber pr essur e [ at m] Fl ow r at e [ koml / hr ] Absor pt i on t emper at ur e [ cent i gr ade] Fl ow r at e Ammoni a l oses Ammoni a l oses [ koml / hr ] NH3 mass f r act i on i n t he gas l eavi ng desor ber Desor pt i on pr essur e [ at m]

22 Solar energy used for CO 2 capture CO 2 + 2NH 3 NH 2 COONH 4 N 2 absorber regenerator NH 2 COONH 4 heat Flue gas CO 2 for sequestration

23 Future work Combined removal of CO 2 /SO 2 /NO x /Hg

24 Future work Ammonia based membrane contactor

25 Future work Carbon sequestration in ecosystem Carbon existing form, and transform between and dependence on different forms Carbon distribution among soil, plant, water, atmosphere, when ammonia bicarbonate is used as fertilizer The impact of ammonia bicarbonate on soil

26 Thanks