New H 2 S Analyser IP 570 Determination of Hydrogen Sulfide in fuel oils – Rapid liquid phase extraction method for Bunker Fuels and Refinery Feedstock

New H2S Analyser

IP 570 Determination of Hydrogen Sulfide in fuel oils – Rapid liquid phase extraction method

for Bunker Fuels and Refinery Feedstock Components

www.seta-analytics.com

H2S a new issue, but of increasing global concern

• H2S present within refineries, terminals, oil storage systems, during bunkering and bunker handling on board the ship, during carriage and handling of crude oils.

• H2S can be released during oil/fuel transportation due to heat & agitation.

• Exposure to H2S has caused death and serious injuries, a significant concern to Underwriters in the Marine industry.

• IMO, major oil companies, shipping companies issue guidelines on the dangers of H2S.

....precise monitoring of H2S concentrations is a major safety concern


Levels of H2S may be found in:

• Petroleum products– petroleum products, especially residual fuel oils that often

contain some dissolved H2S entrapped after processing– crude oils

• Sulfur reducing bacteria– predominantly distillate fuels– does not significantly increase the H2S levels

.... screening for H2S is very important


H2S issues for the Marine/ bunker industry:

• Health and safety

– Colourless and volatile gas– Generates flammable

headspace gases– Highly toxic and potentially

lethal– Acts upon central nervous

system – narcosis– Exposure limits 10 ppm over

a period of 8 hours– Fatalities do occur


L

O

W

0 to 10ppm Irritation of the eyes, nose and throat

M

O

D

10 to 50ppm Headache and dizziness

Nausea and vomiting

Coughing and breathing difficulty

H

I

G

H

50 to 200ppm

Severe respiratory tract irritation

Eye irritation/acute

Shock

Convulsions

Coma

Death in severe cases

H2S issues for the Marine/bunker industry: • Corrosion

– Above the cargo – H2S contributes to mild steel corrosion– On board tankers – potential to damage electronics, instruments and

sensors– Cost!

Need for a robust instrument that offers fast and reliable H2S analysis


H2S within the Marine/ Bunker industry:

• H2S concentration in vapour depends on:

– H2S content in the cargo (liquid phase)– Amount of air circulation– Temperature of air and cargo– Cargo level in the tank– The exact configuration of tank venting arrangements– Amount of agitation– Duration of storage


• H2S within the Marine/ Bunker industry:

• H2S has a high partition coefficient between liquid and vapour – 1 ppm in the liquid phase can give rise to a 100 ppm concentration in a vapour space.

• No proven rules for the tendency of releasing H2S into vapour phase.

....Accurate liquid phase testing of cargo is crucial and the only way to establish true H2S concentrations


Current tests for H2S

IP 399 Determination of hydrogen sulfide in fuel oils

– Complex spectrophotometric procedure– Measures H2S in liquid phase– 3 hour intensive preparation required– Chemical process needs lengthy

technician time– Uses toxic chemicals– Many opportunities to lose H2S vapours


Current tests for H2S

ASTM D5705 - Draeger tubes

• Glass tubes filled with a chemical reagent• 100ml sample of air is drawn through the tube• Colour change indicates concentration

– Easy to use– Poor precision– Only measures H2S in the vapour phase – Some known interferences


New H2S Analyser developed to meet industry needs

Unique NEW instrument for measuring H2S in liquids – Automatic & easy to use– Suitable for Lab or portable testing– precise result in 15 minutes– Pre calibrated detector with a 2 year expected life– Integrated computer, colour display and air pump

Basic principles– Measures H2S ppm (mg/kg) in fuel oils– Utilizes gas extraction combined with an H2S detector– Air is bubbled through the heated sample– Instantaneous readings are integrated and converted to ppm

(mg/kg)


Key Components


Purging


Insert weighed 5 ml sample


Start Test


Calibration

• Static – H2S detector is factory calibrated to give a fixed mV output per ppm v/v

• Dynamic - H2S detector is factory calibrated using two H2S control standards with a known mass of H2S. This calibration then enables results to be shown in ppm (mg/kg)

• Air flow is factory calibrated


Verification

• Using nitrogen containing a certified amount of H2S.

• This can be carried out by the user or distributor

Service

• The calibration of the detector enables a detector to be quickly changed in the lab or in the field by replacing the detector

• Local calibration may be carried out using certified gas



Results

SetaAnalytics

Hydrogen Sulfide Analyser

Instr. S/N : 10001278000000

Sensor S/N : 02.09465093 027

S/W Ver_M : 1.0A

S/W Ver_S : 1.28

Date 02 Nov 2007

Start Time 17:10:07 hr:min:sec

Total Test No. 000105

Sample weight 4.512grams

Test temperature 60oC

Sample ID :

Operator ID ABCA

Test method IP 570

H2S value 1.90 mg/kg (ppm)

Test duration 15 min


Repeatability and Reproducibility vs H2S ConcentrationIP 570

0.00

0.50

1.00

1.50

2.00

2.50

3.00

0 2 4 6 8 10 12 14 16

H2S Concentration (mg/kg)

Rep

eata

bili

ty a

nd

Rep

rod

uci

bili

ty (

mg

/kg

)

Reproducibility

Repeatability

Data courtesy of the Energy Institute


Samples used in the round robin

Sample No. Description Viscosity (mm2/s at 50°C)

1 RFO Vacuum distillation unit feed 677


3 RFO High sulfur visbreaker residue 3000

4 RFO Blend stock 927


6 RFO Blend stock 438

7 RFO with scavenger 2149

8 RFO Cracked vacuum distillate 29.7

9 RFO 380 389

10 RFO 380 363

11 RFO 500 471

12 Diluent oil 65.4

13 RFO 180 211

14 RFO 200 213

15 RFO vacuum residue with scavenger 1986

Data courtesy of the Energy Institute

Latest comparative data:


IP 399 vs IP 570

y = 0.8346x

R2 = 0.9354

0

0.5

1

1.5

2

2.5

3

3.5

4

0 1 2 3 4 5

H2S Level by IP 570

H2S

Lev

el b

y IP

399

Result Data

Linear (Result Data)

Summary:

• The Energy Institute (IP) has published a new test method IP 570• The new Analyser measures H2S in the liquid phase• Good relationship with results from IP 399. H2S analyser has better precision

and can measure to lower H2S levels than IP 399• Precision is excellent• Test times are 15 minutes• Results are simply a ppm (mg/kg) level.• Operator requirements have been considerably reduced• Reliable measurements from 0ppm to 250ppm• RS232 interface• 30 test data storage• Sensor protection with bypass loop• Automatic check for leaks using mass flow controller• H2S limit has been recommended for inclusion within specifications


Typical User Applications

Refineries• to assist control & reduction of H2S during refining processes• Checking of final blended bunker fuels at the refinery tank farm• Checks of product in storage at the refinery & bunker terminal

At loading & onboard ship• To access chemical remediation using H2S treatment additives

New IP 570: Oil and Marine industry moving to adopt this new Analyser for Health and Safety product reasons


Documents

New H 2 S Analyser IP 570 Determination of Hydrogen Sulfide in fuel oils – Rapid liquid phase extraction method for Bunker Fuels and Refinery Feedstock