Co-mingled Biosolids and Biomass as Feedstock for Steam Hydrogasification using a Lab-scale Batch Reactor

Transcription

1 Co-mingled Biosolids and Biomass as Feedstock for Steam Hydrogasification using a Lab-scale Batch Reactor Presented by XIN FAN Research advisor: Dr. Joseph M. Norbeck Dr. Chan S. Park Bourns College of Engineering Center for Environmental Research and Technology University of California, Riverside CERT-SJTU Symposium Dec. 8th,

2 Outline 1 2 Introduction Experimental setup 3 Experimental Results 4 Conclusion 2

3 Basic gasification process Synthetic gas Feedstock Steam O2 /Air Gas Product Gasification Gas clean-up Liquid Fuel Transportation Fuel Gas Heat&Electricity Undesirable impurities Hydrogen source Chemicals 3

4 CE-CERT Process CH 4 + H 2 O H2 feedstock water SHR Warm Gas Cleanup SMR H2/CO Fischer -Tropsch Liquid Fuel product Slurry H2O Steam Hydrogasification Reaction(SHR) C + H 2 O + 2H 2 CH 4 + H 2 O+ CO,CO 2, C Steam Methane Reforming CH 4 + H 2 O 3H 2 + CO Fischer Tropsch Reaction 33H 2 +16CO C 16 H H 2 O 4

5 Advantages of Steam Hydrogasification (SHR) C X HyO z H2O H2 CH4 H2O CO, CO2, C2 Unique feature of SHR is the ability to handle wet feedstock - Reduce the cost of drying feedstock and utilize slurry to pump - Suitable for a feedstock with high moisture content No oxygen or air required -Process is suitable for smaller scale, distributed facilities Can control feed for desired synthesis gas product distribution -Feedstock, Water, Hydrogen input ratio High efficiency at moderate temperature and pressure The CE-CERT process has the potential to be 12% higher efficiency with 18% lower capital cost than the most up-to-date conventional mainstream gasification technologies.* [*]David Gray, C.W., etc, Increasing Security and Reducing Carbon Emissions of the U.S. Transportation Sector: A Transformational Role for Coal with Biomass. 2007, National Energy Technology Laboratory. 5

6 Co-mingled feedstock of biomass and biosolids Biosolids + Steam Biomass Hydrogasification Biosolids Biosolids samples are from Riverside Regional Water Quality Control Treatment Plant. Table2. Main metal elements in biosolids Table1 Proximate Analysis of biomass(pinewood) and biosolids Analysis Compound pinewood Biosolids Proximate Moisture (wt%) Volatile matter Fixed carbon Ash Metal Element Concentration Mass (ppm) Iron (Fe) Calcium (Ca) Aluminum (Al) 3200 Magnesium (Mg) 1620 Potassium (K)

7 Objective Investigate characteristics of steam hydrogasification of co-mingled feedstock Co-mingled feedstock biosolids biomass Steam Hydrogasification Reaction Conditions Evaluate SHR performances of co-mingled feedstock water source: ---moisture content of biosolids total carbonaceous matter : -- mainly from biomass biosolids/biomass mass ratio : ---depends on H 2 O/carbon ratio Compare SHR performances of co-mingled feedstock with biomass feedstock 7

8 Lab-scale Inverted Batch Reactor TC T Reactor Configuration Features Design of pressure-driven feeding system - rapidly load feedstock into the reactor at a constant reaction temperature Design of quartz tube - eliminate Inconel wall effect and collect char Design of inverted impeller configuration - provide continuously stirred environment Motor 8

9 Experimental Apparatus and Approach Feeder tube Inverted batch reactor H2 Residue Gas Analyzer capillary line RGA Experimental conditions Biomass : pinewood( um) Co-mingled feedstock: pinewood +biosolids H2O to carbon ratio: 1:0.45(g/g) Temperature : 700 Balanced H 2 pressure : 270psi weigh char electronic balance product gas Ultimate analysis of pinewood and biosolids Compound pinewood biosolids Moisture C H N O *Balance includes other elements 9

10 Peak intensity(torr) Kinetic model r dm dt ln m m o o m kt Where, m - moles of each product gas generated with time m0 - total moles of the product gas generated k rate constant of the product gas formation t -time CH4 CO CO2 Assumption: product gas is generated by first-order, independent and molecular reaction, each having different activation energy.* Time(min) *Encinar et al.,journal of Chem. Tech.& Biotech., 70 (1997) Product gases evolution with time from on-line RGA data at 700 o C 10

11 Ln(CH 40 /CH 40 -CH4) Kinetic study in SHR 3.5 CH 4 formation 3 wood+biosolids wood+h2o R² = R² = k (CH4) rate constant ln m m o o m kt Time(sec) Rate of CH 4 formation plots in the steam hydrogasification at 700 o C ( biomass feedstock and co-mingled feedstock) 11

12 ln(co 0 /(CO 0 -CO) Kinetic study in SHR 4.0 CO formation 3.5 wood+biosolids wood+h2o R² = R² = k (CO) rate constant ln m m o o m kt Time (sec) Rate of CO formation plots in the steam hydrogasification at 700 o C ( biomass feedstock and co-mingled feedstock) 12

13 Reaction Rate Rate of product gas formation 6 CH4 CO CO2 5 Rate constant k(10-3 sec -1) wood+h2o wood+biosolids The comparison of reaction rates of CH 4, CO, CO 2 formation in the steam hydrogasification between biomass feedstock and co-mingled feedstock 13

14 Carbon conversion (wt%) Carbon Conversion in SHR 100% carbon conversion 80% 60% 40% 20% 68% 73% 0% wood+h2o wood+biosolids The comparison of carbon conversion in the steam hydrogasification between biomass feedstock and co-mingled feedstock carbon left over after the test Carbon Conversion(wt%) carbon in the feedstock 14

15 Conclusion Steam hydrogasification of co-mingled biomass with biosolids in the inverted batch reactor Kinetic parameters in the SHR of co-mingled feedstock were obtained Good agreement with the kinetic model based on gas generation The inverted batch reactor can provide favorable thermal conditions Co-mingled biosolids and biomass as feedstock improved SHR efficiency Reaction rates of product gas CH 4 and CO formation were enhanced compared with biomass only as feedstock Carbon conversion in the SHR was promoted using co-mingled feedstock 15

16 ACKNOWLEDGEMENT Professor: Dr. Joseph M. Norbeck Research faculty: Dr. Chan S. Park Group members Funding support 16

17 Thank you, questions? 17