Dewatering and Deoiling Technology

Copyright ©, Central Research Institute of Electric Power Industry, All rights reserved, 2011

Dewatering and Deoiling TechnologyDewatering and Deoiling Technology

Central Research Institute of Electric Power Industry, JapanCentral Research Institute of Electric Power Industry, Japan

Hideki Kanda, Peng Li, and Hisao MakinoHideki Kanda, Peng Li, and Hisao Makino


Principle of DME Dewatering & Deoiling Technology

5Liquefied DME

Wet & oily materials

Drymaterials

Extraction of H2O & oil by DME

H2O

1 2

1 Wet & oily materials are mixed with liquefied DME at room temperature. 2 H2O & oil are extracted by DME. Dried (dewatered & deoiled) materials are separated from H2O-Oil-DME mixture.

3 Step by step, DME is evaporated. Supersaturated H2O is phase-separated, and is pulled out from the bottom.

4 All DME is evaporated, from Oil-DME mixture, then oil is obtained. 5 DME gas is liquefied by compression or cooling, and is reused.

1 Wet & oily materials are mixed with liquefied DME at room temperature. 2 H2O & oil are extracted by DME. Dried (dewatered & deoiled) materials are separated from H2O-Oil-DME mixture.

3 Step by step, DME is evaporated. Supersaturated H2O is phase-separated, and is pulled out from the bottom.

4 All DME is evaporated, from Oil-DME mixture, then oil is obtained. 5 DME gas is liquefied by compression or cooling, and is reused.

DME gas

3

Oil

4


Compressor

Decompressor

DME vapor

(Condense)

(Evaporate)

Liquefied DME

Extractor

35ºC, 0.8MPaHeat exchangerDistilling

equipment

20ºC, 0.5MPa

Oil

Dry materials

35ºC

20ºC


H2O

Outline of DME Dewatering & Deoiling Process

Theoretical dewatering energy for the compressor is 1109 kJ/kg-H2O.

Deoiling energy is smaller than the above value.H2O saturated concentration in DME is 7-8 wt.%. Oil is mixed perfectly with DME.


30ºC, 0.7MPaHot Source45ºC

Cold Source15ºC

Distilling equipment

DME vapor

Heat exchanger

Heat exchanger

(Condense)

(Evaporate)

Liquefied DME

Extractor

30ºC, 0.7MPaDry materials


OilH2O No compressor is needed.

Earth thermal(<100m)

Industrialplant

Waste heat utilization Energy-saving !DME circulation is energy efficient.


Design & production of the World's 1st prototype

ExtractorExtractorCondenserCondenser

Distilling equipmentDistilling

equipment

CompressorCompressor

Liquid DMEsending pump

Liquid DMEsending pump

Storage tanks Storage tanks

11

22

33

44

55

66

30ºC30ºC0.56MPa，27ºC0.56MPa，27ºC

0.72MPa，43ºC0.72MPa，43ºC


30ºC30ºC0.88MPa，30ºC0.88MPa，30ºC


Distilling equipmentDistilling equipment

CondenserCondenser

CompressorCompressor

Storage tanks Storage tanks Liquid DME sending pumpLiquid DME sending pump

ExtractorExtractor100L/hr100L/hr

φ 15mmφ 15mm

150L150L

φ 150mmL 550mmφ 150mmL 550mm

<400L/hr<400L/hr 100L100L

Heat exchangerHeat exchanger

= 10L/batch= 10L/batch


Wet and/or oily materials

Lignite, Sub-bituminous coal

Oil / PCB / Dioxin polluted sediment

Biomass (especially, Biosolid / Microalgae)

High-efficiency power generation

Carbon-neutral & High-efficiency power generation

Environmental cleanup


Lignite, Sub-bituminous coal (2007)

( hundred million ton）

14971497

26682668 43094309

The World 8474

Reference : Japan coal energy center (2009)

766

43

565

480

16

2427

93Australia

Asia419

Russia

China1145

Europe781

Indonesia

India

USA

South AmericaSouth Africa

Africa

44% 30%26%

31%7%62%

157018%

29% 55%

100%

89% 92%8%

13%41% 46%

42%18% 40%

3%49%48%

26%2% 72% 70

Colombia

95%

93%

13%34% 53%

66Canada

Bituminous coalSub-bituminous coalLignite


Coal dewatering: Results

DME dewatered coal.

Hot dried coal.

Tem

pera

ture

-℃Time -min

0 1000 2000 30000

50

100

150

200

250

Adiabatic temperature increasing by air oxidation.

Indonesian sub-bituminous coal

Coal2.53 kg

DME100L, 1hr

Water content: 40.6 wt.%

Water content: 1.1 wt.%

Energy consumption of the prototype 2069 kJ/kg-H2O

In general, the bigger the DME compressor,the smaller is the power consumed by it.

DME compressor: 3 ton/hr1620 kJ/kg-H2O

Theoretical energy (1109 kJ/kg-H2O)


Biosolids Disposal in JapanHigh-pressure

centrifugation for dewatering up to

78%

Incineration is the favored method.

Biosolids cannot be discharged from wastewater treatment plants.

Japanese people particularly despise offensive odor.

Available volume of sludge

Diffusion ratio

Dif

fusi

on r

atio

Mm3

Slu

dge

volu

me

Year


Deodorization and Dewatering of BiosolidsThermal properties

of biosolids

Originalbiosolids

Deodorizedbiosolids

Odor index 51 20 Hydrogen sulphide Volume (mg/L = ppm) 0.26 <0.003 Methyl mercaptan Volume (mg/L = ppm) 2.60 0.01 Methyl sulphide Volume (mg/L = ppm) 0.280 0.010 Methyl disulphide Volume (mg/L = ppm) 14.000 <0.003 Acetaldehyde Volume (mg/L = ppm) 0.88 0.29 Methyl isobutyl ketone Volume (mg/L = ppm) 5.9 <0.1 n-Butyric acid Volume (mg/L = ppm) 0.0067 <0.005

Odorous components of biosolids

Water content wt.% 78.9 8.0 Crude fat wt.% 8.8 0.6 HHV kJ/kg 19,049 16,801

Deodorizedbiosolids

Originalbiosolids

2.53 kg

DME52.6L0.5hr

Biosolids can be used as carbon-neutral fuel from the perspective of energy balance.


● The fossil fuel has caused environmental issues andwill be exhausted by the near future.

● The biofuel produced from terrestrial crops causedincreasing in world food price and food crisis.

● Microalgae have high CO2 absorption capacity, high oil content, and high growth rate.

● Mass microalgae cultivation can be performed on unexploited land, therefore, avoiding competition for agricultural lands.

Microalgae – A new resource for biofuel


Overall process:

Recovery of green crude oil:

● Species selection● Microalgae cultivation● Recovery of green crude oil (energy intensive)● Biofuel refining

Recovery of green crude oil:● Physical method● Chemical method (thermochemical pyrolysis)

We propose a new recovery method.

Research on microalgae biofuel


Problems of conventional solvent extractionHot drying of microalgae

by sun light etc.High energy use Cell disruption

High energy use

Extraction using toxic organic solventChloroform-methanol.

Cooling

Chloroform-methanol

Green crude oilEvaporation by heating

High energy use

Reuse

For example:Bligh-Dyer’s method by using chloroform-methanolE.G. Bligh, W.J. Dyer, Canadian Journal of Biochemistry & Physiology 37, 1959, pp. 911-917

Water content > 90%by centrifugation

Water vapor

Chloroform-methanolvapor

with H2SO4, HCl

SOX, DXN


Liquefied DME extraction(without drying, cell disruption, and solvent heating)

No drying of microalgae Energy-saving ! No cell disruption

Energy-saving !without H2SO4, HCl

Extraction usingliquefied DME Eco-friendly !

Liquefied DME

Green crude oil

Evaporation of DME at room temperatureEnergy-saving !

ReuseWater content > 90%by centrifugation DME vapor

No SOX, DXNEco-friendly !

Water&

Reuse !


Microcystisslurry.

Water content ishigher than 90%.

Colorless glass beads(Diameter is 1mm)

Extraction column

100μm100μm

DME extraction apparatus

DME & Water& Green crude Mixture

N2

Extraction column10cm3

Filter0.65μm

Liquefied DME 100cm3

Flow speed valve10cm3min-1

DME


DME & Water& Green crude Mixture

Liquefied DME (colorless)running from bottom to top

Glass beadsGlass beads


N2


Filter0.65μm



DME

ColorlessColorless

DMEDME

GreenGreen

Extraction column

MicrocystisMicrocystis


Liquefied DME (colorless)running from bottom to top

Glass beadsGlass beads


N2


Filter0.65μm



DME

DME gas

DME was evaporated at room temperature.

ColorlessColorless

DMEDME

GreenGreen

Green crude

WaterAfter extraction

Extraction column

MicrocystisMicrocystis


6 0 4 8 0 6 0 0 7 2 0 8 4 0 9 6 0

1

2 3 4 5 6 7

9

8 1 0

T i m e ( s )6 0 4 8 0 6 0 0 7 2 0 8 4 0 9 6 0

1

2 3 4 5 6 7

9

8 1 0

T i m e ( s )

Main genus: MicrocystisSampling: Hirosawa mere, Kyoto

DME extraction

GC–MS analysis

C16H32O2

C24H38O4

Lipid

100μm100μm

HHV: 45.8MJ/kg(Gasoline ≈ 43.5MJ/kg)HHV: 45.8MJ/kg(Gasoline ≈ 43.5MJ/kg)

Green crude oil !

Results

From high-moisture microalgaeWithout drying, cell disruption, solvent heating

Energy-saving and simpler method


DME Dewatering & Deoiling Technology

Microalgae fuel productionCleanup of PCB-polluted sediment

Deodorization of biosolid Cleanup of heavy oil-polluted ground


Hideki Kanda, “Super-energy-saving Dewatering Method for High-specific-surface-area Fuels by using Dimethyl Ether”, Adsorption Science and Technology, 26, 345-349 (2008).

Hideki Kanda, Hisao Makino, and Minoru Miyahara, “Energy-Saving Drying Technology for Porous Media Using Liquefied DME”, Adsorption, 14, 467-473 (2008).

Hideki Kanda and Hisao Makino, “Clean up Process for Oil-polluted materials by Using Liquefied DME”, Journal of Environment and Engineering (JSME), 4, 356-361 (2009).

Hideki Kanda, Kazuyuki Oshita, Kazuya Takeda, Masaki Takaoka, Hisao Makino, Shinsuke Morisawa, and Nobuo Takeda, “Dewatering a Superabsorbent Polymer Using Liquefied Dimethyl Ether”, Drying Technology, 28, 30-35 (2010).

Kazuyuki Oshita, Masaki Takaoka, Shin-ichro Kitade, Nobuo Takeda, Hideki Kanda, Hisao Makino, Tadao Matsumoto, and Shinsuke Morisawa, “Extraction of PCBs and Water from River Sediment Using Liquefied Dimethyl Ether as an Extractant”, Chemosphere, 78, 1148-1154 (2010).

Hideki Kanda and Hisao Makino, “Energy-Efficient Coal Dewatering using Liquefied Dimethyl Ether”, Fuel, 89, 2104-2109 (2010).

Hideki Kanda, Mayumi Morita, Hisao Makino, Keizo Takegami, Akio Yoshikoshi, Kazuyuki Oshita, Masaki Takaoka, and Nobuo Takeda, “Deodorization and Dewatering of Biosolids by Using Dimethyl Ether”, Water Environment Research, 83, 23-25 (2011).

Hideki Kanda and Peng Li, “Simple Extraction Method of Green Crude from Natural Blue-green Microalgae by Dimethyl Ether”, Fuel, 90, 1264-1266 (2011).

Kazuyuki Oshita, Masaki Takaoka, Yusuke Nakajima, Shinsuke Morisawa, Hideki Kanda, Hisao Makino, and Nobuo Takeda, “Sewage Sludge Dewatering Process Using Liquefied Dimethyl Ether as Solid Fuel”, Drying Technology, 29, 624-632 (2011).

Kazuyuki Oshita, Masaki Takaoka, Yusuke Nakajima, Shinsuke Morisawa, Hideki Kanda, Hisao Makino, and Nobuo Takeda, “Characteristics of Biosolids in Dimethyl Ether Dewatering Method”, Water Environment Research, in press (Manuscript Accepted for Publication 2011/Aug/11)

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Dewatering and Deoiling Technology