biogas upgrading - german international cooperation based in … · 2019. 4. 3. · to, ko, ro...

1

Biogas Upgrading

Overview of technologies

Measurement technology for process optimizing

Feeding biogas in the gas grid

Requirements for gas quality

Fiscal Measurement technologies

UNION Instruments

2

Company

UNION Instruments• Founded 1919 in Karlsruhe• Locations in Karlsruhe and Lübeck

Development and production of measuringdevices• Gas analysis : gas properties, energy• Gas analysis: gas composition• Pressure und temperature recorders (gas and water)

Main customers• Industries: Steel, Glas, Oil and gas)

Worldwide distribution

Topic3

How can existing plants install biogas upgrading facilities?

Overview of different German technology options for upgrading biogas to

Biomethane

Comparison single level and multi-level methods

Feeding Biomethane into the natural gas grid

requirements on gas quality

Matching measurement technology to optimize product quality and energy

Requirements for the measuring technology of Biogas pipeline injection

according G260/262 related to Energy measurement , Gas quality and Gas

conditioning to pipeline quality

In an anaerobic environment and with the presence of bacteria, organic material will undergo a physical, chemical and biological Process.

With the right temperature, the bacterial Anaerobic Digestion will take place while converting the complex organic matter into much simpler gaseous compounds.

Anaerobic digestion generates Biogas with a high fraction of CH4 and CO2 and a small portion of some other gases (NH3, H2, H2S, etc.).

Cleaned Biogas (removal of H2S, NH3, dust and water) can be used for power or heat generation on site

General Information Biogas4

Where does it comes from?

What is it?

What can I do with it?

Biogas qualities5

Component Raw Biogas Landfill gas

Methane CH4 45 - 70 % 35 - 55 %

Hydrogen H2 < 200 ppm 0 – 0,2 %

Carbon Dioxide CO2 30 - 45 % 40 – 60 %

Nitrogen N2 0 - 2 % 2 - 25 %

Oxygen O2 0 - 0.5 % 0 - 6 %

Trace Elements Hydrogen Sulphide H2S < 300 mg/m3 n.a.

Siloxanes SiOx < 100 mg/m³ n.a.

Hydrocarbons CxHy < 100 ppm v n.a.

Water H2O saturated saturated

Energy

CharacteristicsGross Calorific Value HS,N 5.0 – 7,7 kWh/m3 3,8 – 5,5 kWh/m3

(Dry gas) 455 - 710 Btu/ft³ 350 - 550 Btu/ft³

Wobbe Index WS,N 4,77 - 8.4 kWh/m3 3,5 - 6,1 kWh/m3

436 - 770 Btu/ft³ 325 - 560 Btu/ft³

From biomass to electrical power &

biomethane

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Conventional Direct Electrification Grid Injection & Decentralised Utilisation

Biogas Upgrading

Biogas Production

Biogas

Off-gas

+

Heat Export

Biomethane

Grid

Injection

Biomass

Slurry

CHP On site

CHP

CHP

Power

HeatPower

Heat

Industry & households

CNG Vehicle fuel

Na

tura

l Ga

s

Grid

Advantages:

Better Heat Concept Highest CO2-reduction potential

High energy utilisation Lowest emissions

Highest added value High CHPP-Efficiency

Disadvantages:

× Marginal/No Heat Concept × Low CHP-Efficiency

× High CHP-emissions × Low energy utilisation

× High CHP-methane loss(2-5%)

× Energy wasted

(>30%)

© Schmack Biogas

CNG Vehicle fuel

Options: Usage of Biogas7

Energy production at

the site

from Raw biogas

Upgrading and gas grid injection Energy production at

the site

from Biomethane

Biogas

CHP Cogeneration

(local)

Power Heat

Heat demand on

site often to low or

non-existent

UpgradingCHP Cogeneration

(local)

High energy

efficiency

Bio natural gas Power Heat

CNG fuel

Gas grid Injection

Heat fuel CHP Cogeneration(local)

Power Heat

High energy efficiency

Requirements for biogas upgrading

Raw biogas quality must be suitable for upgrading

Oxygen and nitrogen concentrations will increase costs for upgrading

High concentrations of trace components like siloxanes will increase costs for Raw biogas cleaning and gas analyzers

Natural gas grid must be in vicinity

Capacity of the gas grid must be higher than Biomethane production at all times

CNG fuel market must exist

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Biogas upgrading

Flow comparison

9

Compression &

CoolingProcess

H2S

Removal

Methane

enrichmentGas Drying Off-Gas treatment prior disposal

Chemical

Scrubber

Bio

gas

8 - 10 bar

0.1 - 0.3 bar

Water

Scrubber

Activated

Carbon

Activated

Carbon

2 or 3-Step

Membrane

Scrubber

ScrubberRegen.

Tower

Regen.

TowerGas Dryer

Water Air Heat

Heat

H2S

Scrubber

Off-Gas

Cleaning

System

Biomethane

Biomethane

Biomethane

Off-Gas

Cleaning

System

Off-Gas

Cleaning

System

PSA3 - 5 bar

Activated

CarbonPSA Biomethane

Off-Gas

Cleaning

SystemMembrane

8 - 16 bar

Gas Dryer

Flow diagram Evonik Membrane Biogas

upgrading

10

CoolingPre-compression

and drying

Particle filter Control filterTemperature

control

Membrane

Stage II

Membrane

Stage I

Membrane

Stage III

TO, KO, RO

Biogas

Gas separation

Pre-treatment

Biogas production

Purification

Off-gas treatment

Compression

CompressorDesulfurization

Biomethane

> 98 % CH4

Off-gas CO2< 0.5 % CH4

Purified gas

0.0 % CH4

option

Membrane technology11

Function of the highly selective

membrane

Gas permeation using

selective membranes made

from high-performance

polymers

Design of membrane module

Biogas: CH4 + CO2 (feed)

Biomethane: CH4(retentate)

Off-gas: CO2(permeate)

Hollow fiber membranes

Separation of CO2 and CH4based on differing permeation

velocities

CH4 slow

CO2 fastEISENMANN


Gas separation with highly selective membranes

Membrane

Stage II

Membrane

Stage I

Membrane

Stage III

Compressor

Biomethane

> 98 % CH4


EISENMANN


Machine room – compressor (Ex-II), membrane room – gas separation (Ex-II), gas analysis room,

switch cabinet

10 m

3 m

EISENMANN

Selexol scrubber14

Schwelm Anlagentechnik GmbH

Selexol scrubber15

Schwelm Anlagentechnik GmbH

PSA (pressure swing adsorption)16

Main Characteristics:

Separation through molecular sieve effect.

Biomethane production at elevated pressure CMS regeneration at low pressure.

Selective & simultaneous separation CO2, H2O, H2S, NH3, partially N2 & O2 Operational pressure range 1 – 7 bar

Upgrading process at ambient temperatures 5 – 35°C

CMS fully self-regenerated

Gas molecules:

CH4

N2 / O2

H2O/ H2S

CO2

Carbon

Molecular Sieve

(CMS)

Biogas

Biomethane

Compressor Vacuum Pump

CH4 / CO2 / N2/ O2 / H2O / H2S CO2 / N2/ O2 / H2O / H2S / CH4

% CO2-Biogas

Power needed

kWhel/m³

304050

0,15

0,20

0,25

Carbotech (Viessmann Group)

Monoethanolamin scrubber20

MT Biomethan

Monoethanolamin scrubber21

MT Biomethan

System comparison (1/2)22

Properties of different gas cleaning and methane enrichment technologies

AttributeWater

Scrubbing

Polyglycol

Scrubbing

Amine

Scrubbing

Pressure

Swing

Adsoption

Membrane

Process

Air intake into

Biomethane by

stripper columnyes yes no no No

O2-/N2-

enrichement by

CO2-Removalyes yes yes no yes

CH4-losses medium medium very low medium medium

Product gas post

drying stepyes yes yes no no

H2S-pre cleaning

necessary

no

(yes)yes yes yes yes

System comparison (2/2)23

AttributeWater

Scrubbing

Polyglycol

Scrubbing

Amine

Scrubbing

Pressure

Swing

Adsorption

Membrane

Process

Overall Utility

demand:

power, water, heat,

cooling water,

activated carbon,

washing medium

medium medium high - No high

Power demand

(kWelectr)

(autarkic System)

~ 0,26-0,32

kW/m3 Raw gas

~ 0,24-0,28kW/m3 Raw gas

~ 0,08-0,12kW/m3 Raw gas

~ 0,16-0,22kW/m3 Raw gas

~ 0,26-0,34kW/m3 Raw gas

Heat demand

(kWtherm)none

~ 0,1kW/m3 Raw gas

~ 0,7 - 0,8kW/m3 Raw gas

none none

CO2-footprint from

utilities

consumption

~114-141

g/m3 Raw gas

~144-153g/m3 Raw gas

~206-293

g/m3 Raw gas

~70-97g/m3 Raw gas

~123-150g/m3 Raw gas

Properties of different gas cleaning and methane enrichment technologies

System optimisation

frequent reasons of energy losses

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Technical hardware problems in the upgrading facility

Methan losses in the gas compressor (to atmosphere)

Leackages in valves (increase off gas losses)

Wrong process settings

Wrong adjustment of washing liquid flows, temperature and pressures.

Incomplete stripping of CO2 caused by low temperatures in the stripper column

Blockage in the process

Blokage of the adsorber by H2S

Decomposition of the washing liquid (to high temperatures in the stripper

System optimisation

methane losses

How can we detect methane losses ?

Methan losses can be detected by balancing the

methane flows in the system.

How can we balancing the methane flows ?

For balance we have to measure the flows and

the methane concentrations in the flows.

All measurements for the balance must be

done with a high accuracy.

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Measuring points for system

optimisation (example membrane)

26

CoolingPre-compression

and drying

Particle filter Control filterTemperature

control

Membrane

Stage II

Membrane

Stage I

Membrane

Stage III

TO, KO, RO

Biogas

Methane balance

CompressorDesulfurization

Biomethane

> 98 % CH4


Purified gas

0.0 % CH4

option

Energy and quality

optimisation

Reliability

Biomethane to grid injection

Typical natural gas qualities

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Component German G260/G262

Gas Pipeline Tariff

TETCO (Texas

Eastern)

Methane CH4 n.a. % > 75 %

Hydrogen H2 < 5 % n.a.

Carbon Dioxide CO2 < 6 % < 3 %

Nitrogen N2 n.a % < 1 %

Oxygen O2 < 3 % < 0.2 %

Trace Elements Hydrogen Sulphide H2S < 5 ppm < 8 ppm

Siloxanes SiOx n.a. n.a.

Water H2ONon condensing under

pipeline conditions

Energy

CharacteristicsLow Calorific Value Hu,N 8,4 – 13,1 kWh/m3 ≈ 9.77 kWh/m3

≈ 967 Btu/ft³

Wobbe Index WS,N 12,8 – 15,7 kWh/m3 n.a. kWh/m3

n.a. Btu/ft³

Biomethane to grid injection28

Adjustment of Energetic Properties: Wobbe Index and Calorific Value

Addition of LPG / Air / CO2 (if necessary)

Targets to be accomplished for the injection of biomethane into the grid:

Matching Wobbe index and Calorific Value Dew point - gas dryness

CO2-fraction limit (%) Free of dust or any foreign particle

O2 / N2-fraction limit (%) Matching pressure

Trace limits: H2, H2S, Siloxanes, CFHC, etc. Adding odour

kW

h/m

³

MJ/m

³

Defining the Quality of the gas


Matching the operational pressure:

Type Pressure (bar)

Common Network

Pipelines

Int. Long-Distance Transport Grid 70-120

Local Transmission System (LTS) 7-16-40-70

Medium / Intermediate Pressure 1 - 7

Low Pressure (LP) < 0.075

Monitoring of the Bio-Natural Gas (Conditioned Biomethane)

• Oxygen Monitoring

(redundant, Paramagnetic Sensor)

• Gas quality Adjustment Unit (Calibratable)

• CV, Density and CO2-concentracion is measured • Gas meter (Screw type gas meter)

Biomethane to the Grid InjectionFundamentals


Biomethane Conditioning & Grid Injection Unit

Gas Grid

Biogas Production & Upgrading

Odorizing

THTLPG / Air

Caloric Value Adjustment

Unit

SAV

Safety Valve

Flow

Calibrated flow measurement

Pressure Control

PCV

Biomethane to the Grid

Biogas Producer / Grid Company

biogas production

biogas upgrading

Overview of the process scheme options

PGC or

Calorimeter

Energy metering system

Raw biogas

31

CWD2005 CT

Biogas

Flow computer

VCC

flow

mete

r

Encoder 1Vb

T

Heated cabinet

Modbus

RS232

Modem

GSM

Archivemaintenance

(CL)

Modbus(RS232)

Gas p

ipelin

e

Heated line 6 mm

EX

barriere

K920

ESS

Encoder 2Heating value

SNK 971

Insolation Signaling cable

Energy metering of Raw biogas

calorimeter solution

32

Heated cabinet with calorimeterand flow computer

Ultrasonic Flowmeter with fow computer

Designed to measure wet gases

up tp water dewpoint of 40°C

High accurate calorimeter

measurement better 0,5% of

reading

Automatic calibration

8 years calibration period of flow

meter

Engergy metering system

NDIR solution

33

NDIR analyzer in heated cabinet (50°C) Eenergy metering control panelINCA analyzer control panel

Ultrasonic Flowmeterpressure and temperature sensors

Designed to measure wet gases

up tp water dewpoint of 45°C

Cross sensitivity detection by dual

wavelength NDIR measurement

Automatic calibration with air and

methane

8 years calibration period of flow

meter

Gas measureing technologies

Calorimeter

Direct energy measuring principle by burning the gas

Gaschromatograph

Selective gas analysis by using adsorption an desorption

properties in seperation columns

NDIR sensors

Determination of gas concentrations by measuring the

absorption of light in a defined spectral range

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Fiscal natural gas analyzer

Calorimeter (BTU analyzer) prinziple

35

Fuel gas

Cooling air

Cooling air + flue gasDry Calorimeter

Calorimeter CWD2005 CT36

Direct BTU measurement

No cross sensitivities

Fiscal approval for Natural gas

and Biomethane

One gas calibration

Measured values

Wobbe index

Specific gravity

Calculated values

Heating value

Air demand

Gaschromatograph Sitrans CV37

Sitrans CV

Geräteaufbau

38

Analytic module

Communication &

Energy

Gas supply & probe

Control

module

Siemens Sitrans CV

Analysemodul

39

Live-Switching

Columns

Ofen

Detector

Detector

Siemens Sitrans CV40

Analytical configuration and seperation of components

NDIR – non dispersive infrared41

Measurement principle:

Measuring the absoption in a defined spectral range

heated

chamber

input

filter + receiver

reference

IR-source

output

filter + receiver

signal

pressure

sensor

Detection Range

CH4 0 - 100 vol.-%

CO2 0 - 100 vol.-%

C2+

(CxHy)

0 - 15 vol.-%

NDIR – non dispersive infrared

cross sensitivity detection

42

2.50 2.86 3.33 4.00 5.00 6.66 10.00 20.00

100

80

60

40

20

0

Wavelength [mm]

Tra

nsm

issio

n

[%]

MethanEthanPropanButanMeasurement

range 13.5 [mm]

Measurement range 27.9 [mm]

Principle:

Detection of cross sensitivities by measuring in different spectral ranges.

A drift between the values indicates a cross sensitivity in the process or

calibration gas.

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UNION Instruments GmbH

Zeppelinstraße 42

76185 Karlsruhe

www.union-instruments.com

[email protected]

http://www.union-instruments.com/

List of manufacturer Biomethane facilities44

Water scrubber Amin scrubber PSAMembrane

technology

• Greenlane

(Flotech)

• Malmberg

• Cirmac

• Purac

(Läckaby Water)

• MT Biomethan

• Strabag AG

• Bilfinger EMS

• Carbotech

• ETW Energietechnik

GmbH

• Mahler AGS

• Eisenmann

• Himmel Gastechnik

• Methapower Biogas

GmbH

• Pentair Haffmans

• MT Biomethane

• Borsig Membrane

Technology GmbH

• Air Liquide

• Envitec Biogas

• Cirmac

biogas upgrading - german international cooperation based in … · 2019. 4. 3. · to, ko, ro...

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