Supercritical conversion

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Godwin Parsons
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Supercritical conversion design of the scaled unit in the Czech Republic Marek Šváb, Karel Ciahotný 20.5.

1 Supercritical conversion design of the scaled unit in the Czech Republic Marek Šváb, Karel Ciahotný , Dresden 1 Supercritical water (SCW) Unique properties ( between liquid and gas ) Totally different from ordinary water Relative permitivity: ~5 (80) SCW = non-polar solvent (benzene: 2,3, hexane: 1,9) reactions of organic species and gases in dissolved state (homogneous) Low ion product (10-24 ) Low density Low viscosity Low surface tension Others 2 1

Supercritical water gasification (SCWG) = SCW is both solvent and gasification agent SCWG promises: Suitable for wet fuel, or aqeous solutions Energetic efficiency is not decreased by fuel moisture.

of harmfull species 3 Supercritical water gasification (SCWG) = SCW is both solvent and gasification agent SCWG problems (main): Material requirements in the technology >22 MPa, 450 600 (700) C,

2 Supercritical water gasification (SCWG) = SCW is both solvent and gasification agent SCWG promises: Suitable for wet fuel, or aqeous solutions Energetic efficiency is not decreased by fuel moisture. Production of compressed gases Disposition for low tar and char production (homogeneous reactions) Possible separation of CO 2 under high pressure Heteroatoms and solids remain in water Decomposition of harmfull species 3 Supercritical water gasification (SCWG) = SCW is both solvent and gasification agent SCWG problems (main): Material requirements in the technology >22 MPa, (700) C, corrosion fluids Stainless steel 304/316 Special alloys (Hastelloy, Inconel, Incoloy ) Conversion / energetic efficiency zero balance = processing of the liquid containing at least 10 % of organics Denser input material = problems with conversion efficiency Need of recuperation heat exchanger as efficient as possible Expensive and big apparatus Risk of clogging of exchanger/reactor insoluble inorganics in SCW Tars, chars 4 2

3 What to do with SCWG? Speculate, doubt, believe or to try it! 5 Experimental scaled ( pilot ) unit in C.R. - background Preliminary calculations, consultations with various experts (2012) No fundamental obstacle for the unit construction was identified. Funding Czech Technology Agency (from 2013) Finishing winter 2013 / 2014, TÜV certification 6 3

4 Simple scheme of the plant ZAHYKORMA 01 Continuous system, 26 MPa, 600 C, 1-2 L/min gas sampling substrate safety valve ~15 C 20 C ~ 290 C safety valve cooling exchanger filter BPR 38 kw 64 kw ~10 C ~380 C ~40-50 C (max.) separator liquid pump recuperation exchanger ~520 C 50 kw reactor/furnace water 7 Realization story with good ending conflicting requirements from various fields, many problems Chemical-engineering-construction-managing-economical brain-twister Main process parameters design (i.e.residence time, cleanability ) thicker pipe HP pump flow rate slower heat transfer amount faster better flow character. heating furnace thinner heat transfer thicker design, control Heat transfer calculations requirements (thinner) strength calculations requirements thinner thinner side, longer thicker thicker side, shorter material standards ASME, EN Notified person supervision (TÜV) Safety (HAZOP) expenses, terms material availability material price suppliers too small order too difficult order 8 4

5 Key parameters Max. Pressure 26 MPa Max. Temperature 600 C Flow rate 1 2 L/min Furnace power 50 kw Main exchanger heat transfer 64 kw Cooling exchanger heat transfer 38 kw Retention time in the reactor min Volume of the pressure part 49 L Material SS 304/304L + SS 316 Flange, gasket ring pipe 9 Supervision by the TÜV Pressure test Detail cooling of lags for pressure sensors High-pressure part (before isolation) 10 5

cz Authors would like to thank for financial support to the

6 Temperature sensor placed on the outer surface of the pipe (under isolation) 11 Thank you!!! questions? Authors would like to thank for financial support to the Technology Agency of the Czech Republic (project no.: TA ). 12 6

7 Experiences, R & D in the world Principle known from 70. (MIT) Increase of interest last 10 years No commercial use, yet Laboratory research groups (examples): Forschungzentrum Karlsruhe (Germany); Univerzity and National Institute of Advanced Science and Technology, Hiroshima, Japan; Natural Energy Institute, Hawai, USA; Pacific Northwest National Laboratory, Richland, USA; ETH Zurich, Switzerland; University of Leeds, UK; University of Twente, Netherlands; Xi an University, China and others. There is one pilot-plant (VERENA, Karlsruhe, Germany) 13 Control panel 14 7

8 Cost ~ CZK ~ Eur 15 8

Oxidation of Hazardous Wastes by Supercritical Water Oxidation(SCWO)

Oxidation of Hazardous Wastes by Supercritical Water Oxidation(SCWO) SuperCritical Water Oxidation (SCWO) is an end of pipe technology applicable to industrial waste effluents or sludges breaking down