Specialty Chemical Manufacturing, Marketing, & Distribution
DNP-02-00-2022 Sulfide Scavenger Concentrate
Organic, formaldehyde free hydrogen sulfide
scavenger (80%) concentrate
DNP-02-00-2033 Sulfide Scavenger
Thermally stable methyl amine triazine
DNP-02-00-2064 Sulfide Scavenger
Blended Ethanolamine formaldehyde
DNP-02-00-2100 Oil Soluble H2S
Scavenger Branched alkyl triazine (100%)
DNP-02-00-2301 H2S Scavenger
EDA / MEA triazine
DNP-02-00-2411 H2S Scavenger
MEA balanced triazine
DNP-02-00-2414 Metal Complex for
Amine Fe III Solutions with Hydrotropes
Crosslink Oil Gels
DNP-02-00-2431 H2S Scavenger
MEA condensate
DNP-02-00-2446 Metal Complex for
Amine Fe III Solutions with Hydrotropes
Crosslink Oil Gels
DNP-02-00-2449 Metal Complex for
Amine Fe III Solutions with Hydrotropes
Crosslink Oil Gels
DNP-02-00-2601 Oil Soluble H2S
DNP-02-00-2800 Liquid KCL Substitute
Scavenger Schiff base
Ammonium salt of an Organic Acid (70-75%)
DNP-02-00-2810 Defoamer Concentrate
High molecular weight alcohol based defoamer/
DNP-02-00-2815 Defoamer Conventrate
Antifoamer
Silicone based Defoamer/Antifoam concentrate
DNP-02-00-2825 Multi-purpose iron complexing
Reducing agent for ferric iron in acids
DNP-02-00-2830 Calcium Sulfate dissolver
Concentrated, water soluble organic
DNP-02-00-2835 H2S Scavenger
Scavenger plus anionic surfactant - OS
DNP-02-00-2845 Oxygen Scavenger
Ammonium by sufite solution with nickel
Catalyst (70%)
H2S Scavenger Series
condensates
Specialty Chemical Manufacturing, Marketing, & Distribution
Direct N-Pakt’s H2S Scavenger — Properties
Product
#
Density
Active %
#/gal
~
Content
Application
Soluble
pH
water %
Gas
Oil
Water
In
2022
80
9.6
12
18
X
X
X
water
2033
45
8.3
11
55
X
X
X
water
2064
67
9.3
12
30
X
X
X
water
2100
98
7.5
11
<2
X
X
--
oil
2151
54
9.3
11
42
X
X
X
water
2301
80
9.5
12
20
X
X
X
water
2411
52
9.2
9.6
44
X
X
X
water
2431
54
9.1
12
42
X
X
X
water
2601
2835
81
78
6.9
8.5
12
9.5
<1
8
X
X
X
X
---
oil
oil
H2S Scavenger Series
DNP
Specialty Chemical Manufacturing, Marketing, & Distribution
HYDROGEN SULFIDE SCAVENGERS FOR:
HYDROCARBON GASES, CRUDE OIL, AND ASSOCIATED WATER SYSTEMS
AUGUST 13TH 2010
The Hydrogen Sulfide Scavengers (H2S Scavengers) from Direct N-Pakt are primarily those of
methylene reacted systems.
Also, the flow stream may purge through column known as a scrubber with fluid volume and percolate
bubbles for intimate contact.
The chemical molecules can be called Schiff bases, imines, methylene bridged adducts, methylolated
amines, triazines, bis-oxazolidines.
H2S Scavenger Properties
Aldehyde
At 20° C Density to Amine
Name
g/cc
#/gal
% by weight
active
Ratio
free
amine
T
water
MEOH
pH
2022
1.14
9.6
1 to 1.08
80
4.82
74.44
18.35
0 11.5-12.5
2033
1
8.3
1
45
nil
45
55
2064
1.12
9.3
1 to 1.13
67
5.77
67
30.22
2100
0.9
7.5
1:01
98
<1
0
<2
0
10-12
2151
1.09
9.1
1 to 1.09
53
3.56
49.32
43.29
3.38
10-11.5
2301
1.14
9.47
NA
80
NA
64.55
20.73
0
11-12
2411
1.15
9.2
1:01
52
0
52
44
4
9-9.5
2431
1.09
9.09
1 to 1.17
54
6.71
47.51
42.08
2601
0.85
7.08
ND
81
ND
0
9.6
0
10.5-12
2835
1.03
8.58
ND
76
ND
1.9
30
8
10.5-12
0
10 -11.5
1.83 10.5-12.0
3.65 10.5-12.0
Typical treatment rates are 0.16 to 0.45 liters per MMSCF for line injection.
Gals/ day = 0.04 to 0.06 x MMSCFPD gas x ppm H2S typical for towers.
Typical reaction ratio is 4:1 chemical to H 2S, up to 25 ppm. In some cases % solutions might
be required.
H2S Scavenger Series
These hydrogen sulfides can be removed from the gaseous, hydrocarbon liquid, or water phases by
direct treatment into the flow stream.
Specialty Chemical Manufacturing, Marketing, & Distribution
HYDROGEN SULFIDE OCCURRENCE AND REMOVAL
AUGUST 15TH 2010
Hydrogen sulfide is a commonly occurring nasty, toxic, and lethal gas. Hydrogen sulfide is colorless.
Hydrogen sulfide must be reduced to permissible levels for safety and corrosion standpoints, typically 1 to
4 ppm (mole % basis). Severe concern is considered when H2S is above 100 ppm.
Hydrogen sulfide is very corrosive when dry forming FexSX complexes, very adherent, and interferes with
flow passage of gas, especially in dry gas pipelines.
Hydrogen sulfide occurs form generation by growth of anaerobic (grow in area where oxygen is absent)
bacteria called sulfate reducers (common name).
Hydrogen sulfide can be produced from the decomposition of waste, garbage, and compost domes.
Hydrogen is produced from handling of sulfur from some natural gas wells, from leakage from storage
domes.
Hydrogen sulfide is produced in high quantities from natural gas and associated gas from oil wells
throughout the world, especially in Canada, Southern US, Mexico, Russia, Iran and others.
Due to producing or disposal or storage of associated brine production in oil and gas production, waters
accumulate H2S from handling and bacterial contamination.
Corrosion Problems:
Locations:
Producing from oil/gas formation-down hole tubulars.
Wellhead flow, under high velocity.
Flowlines and gathering vessels.
Gas/oil/water separators.
Gas processing plants.
Transportation of unsweetened (H2S removed) gas.
Vapor space of liquid storage( stock) tanks.
Amine sweetening systems.
Dehydration of gas units.
Crude shipment by barge, ship, pipeline to refineries.
Crude loading and offloading systems for processing.
Crude oil towers to breakdown fractions of the oil.
H2S Scavenger Series
Hydrogen sulfide gas occurs in wet forms in sewage drains, holding pits, and plants at toxic levels,
generated from decomposition of fecal matter.
Specialty Chemical Manufacturing, Marketing, & Distribution
HYDROGEN SULFIDE OCCURRENCE AND REMOVAL (cont.)
AUGUST 15TH 2010
H2S Scavengers:
Direct N-Pakt manufactures liquid chemical reagents to remove or lower the hydrogen sulfide content,
occurring at low % or low ppms.
Direct N-Pakt chemical scavengers will reduce the level of hydrogen sulfide to where corrosion can be
controlled , the IRON (Fe) sulfides can be minimized.
The solids of FexSx can cause plugging in disposal or secondary water injection systems. Oil dehydration
upsets and problems can be reduced by limiting the solids, including the reaction products and the Fe xSx.
CHEMICALS:
Direct N-Pakt supplies liquid scavengers that are useful in treatment of natural gas, carbon dioxide with
associated gas, liquid condensates or crude oil, and waters of various types, including refinery process,
produced oilfield waters, sewage, drilling fluids and fracturing fluids.
Direct N-Pakt supplies H2S scavengers that are:
gas soluble
oil soluble
water soluble
Gases associated with oil and gas production usually contain CO 2 (carbon dioxide), which causes an
acidic pH. The addition of H2S scavengers to CO2 containing fluid can cause pH to rise sharply. The
formation of calcium or magnesium carbonates and amine carbonates can occur. Direct N-Pakt H 2S
scavengers usually hold this to a minimum, but it does occur.
In these cases, the DNP-02-00 2022, contains a chelant. Other products and 2022 can use the addition of
Direct N-Pakt’s high calcium tolerant phosphonates, which are both sequestrants and chelants, @ 1-2%.
The common added is DNP-06-00-68441 or 68481, or 68521. These phosphonates also help to dissolve
Fe xSx.
Formaldehyde can be added to the Direct N-Pakt line of H 2S scavengers except the oils soluble; 2100,
2601, or 2835, to synergize or accelerate reaction ratios.
The use of Direct N-Pakt’s H2S scavengers can be coordinated with using proper Corrosion Inhibitors to
mitigate even low level of H2S or in process areas not previously removed of H 2S.
Technical information is supplied for the Direct N-Pakt’s H 2S scavengers and their handling.
H2S Scavenger Series
Direct N-Pakt supplies both chemicals and technical expertise in handling of chemicals and their
applications. Direct N-Pakt can supply specialty blends for particular use.
Specialty Chemical Manufacturing, Marketing, & Distribution
H2S TREATMENT RATIOS IN VARIOUS EXPRESSIONS
AUGUST 13TH 2010
Triazines supposedly react at 1 mole removes 3 moles of Sulfide (not as H 2S).
Molecular weight of ethanol amine triazines is 219.
Reaction is 3 x 32 =96 mole weight of 3 sulfides. So 2.28 parts of triazine per 1 part of sulfide.
Theoretical relation of standard triazine as 2151, is 1.71 # (0.14 kg/liter) removed by 1 gallon,
for a ratio of 7.4
Overspent relation of standard triazine as 2151, is 1.78 # removed by one gallon,
for a ratio of 4.87.
Note the overspending:
Assumes 8.66 #/gallon density for 1 gallon.
@ 9.08 #/gal, 1.17=7.76 ratio. 1.78 = 5.1 ratio.
Most of the triazines use a factor of 3 to 3.3 in the calculation:
Chemical [liters per day]=ppm H2S x MMscf/d divided by factor.
This is 0.333 to 0.303 for LPD or 0.088 to 0.08 GPD
1 Liter of scavenger will remove 3.2 ppm of H2S from one MMscf gas.
0.5 Liter of scavenger + 0.5 liter of 37% formalin will remove 5.6 ppm H2S from one MMscf gas.
I gallon of scavenger will remove 12.1 ppm of H2S from one MMscf gas.
16 ppm H2S will be removed from one MMscf gas per gallon of scavenger.
1 gallon= 16/ppm H2S/ MMscfd
gallons/day= 0.0625/MMscfd/ppm H2S
1/16=0.0625 x 3.785 = 0.2366 liters/ppm H 2S/MMscfd
1/14=0.0714 x 3.785 = 0.2704 liters/ppm H 2S/MMscfd
1/21=0.0476 x 3.785 = 0.18 liters/ppm H2S/MMscfd
1/47=0.0213 x 3.785 = 0.08 liters/ppm H2S/MMscfd
Liters/day per 3.785 liters/gallon = 0.2642 gallons/day
H2S Scavenger Series
@ 50% active the ratio of Chemical to sulfide is 2.28/0.50= 4.56
@ 60% active the ratio of Chemical to sulfide is 2.28/0.60= 3.8
@ 80% active the ratio of Chemical to sulfide is 2.28/0.80= 2.85
Specialty Chemical Manufacturing, Marketing, & Distribution
Most Efficient H2S Scavengers
August 14th 2010
The question comes from which are the most effective and which are the fastest and which are best
suited for what system.
Schiff Base
Imine
Methylene Bridge
Triazine
Other
The steric hindrance can interfere or control rate. Rate controls efficiency.
Methyl amine – CH3NH2
AEW =31
Ethylene diamine – H2NCH2CH2NH2 view as dimer of methyl amine.
AEW =30
Ethanolamine- HOCH2CH2NH2
AEW =61
Diethanolamine- [HOCH2CH2]2NH
AEW =105
Di-n-butylamine – [CH3CH2CH2CH2]2NH
AEW =129
Rohm & Haas Primene 81-R C12-14 tertiary carbon, primary amine or similar
Hypothesis can be forever and techniques to test structure are eluding.
The reactant is methylene [CH2] to form a stable reaction product. Therefore the molecule must use its
amine for capture and the methylene must be easily released in the system. The system can be gas,
hydrocarbon liquids, aqueous liquids, or mixtures. The methylene of formalin is the most reactive.
For towers, the product density has a physical effect, as well as it should not easily carry with the gas if
radial velocity is exceeded. Considered the most for money is MEA triazine or this MEA/CH 2O reaction
product mixed with formaldehyde, if local restrictions or companies allow.. Some have discussed DEA
as some improvement. EDA can be used as well.
H2S Scavenger Series
The first question is how they exist:
Specialty Chemical Manufacturing, Marketing, & Distribution
Most Efficient H2S Scavengers (cont)
August 14th 2010
For Line Injections consider as: Towers as well
CH2, %
Soluble In
Gas/Air Hydrocarbons Water
Methylamine
2033
13.84
yes
yes
yes
MEA
2022
14.28
nil
nil
yes
MEA
2064
11.71
nil
nil
yes
MEA
2151
9.46
nil
nil
yes
MEA
2411
9.94
nil
nil
yes
MEA
2431
9.13
nil
nil
yes
2301
15.41
slight
slight
yes
nil
slight
yes
yes
yes
slight
yes
yes
slight
MEA/EDA
DEA
di-n-butylamine
Primene 81-R
Amine
-------2601
-------2100
37% Formalin -------MEA
2835
-------8.4
-------19.4
yes
yes
slight
17.27
yes
yes
yes
5.71
nil
yes
slight
It must be noted that the reaction products continue to react, saying reaction products react further.
The form sought is S-S-S or maybe S-S-S-S-S. This is achieved from the (CH2-S) n, where n= most
commonly 3 and 4.
Trithiane is usually present in small quantities. CS2 is present and dithianes.
MEA is typically the lowest cost. MMA is expected to perform but may be too volatile for most producers
to handle.
Original formulas were formalin with DEA added.
Gatlin has patent on DMAPA assigned to WFT, Dimethylaminopropyl triazine, also made by Taminco.
H2S Scavenger Series
DNP
CH2O Rxn Product
#
Specialty Chemical Manufacturing, Marketing, & Distribution
FORMALDEHYDE AMINE REACTIONS with CONDENSATIONS and LIQUIDS
15th August 2010
The reaction of formaldehyde, including formalin (37% inhibited with 3 to 25% methanol), 49-51% tackifier
grade, or methyl formcel (normally 55% formaldehyde in 35% methanol and 10% water) with primary or
secondary amines is an exothermic condensation to form methylol groups, Schiff Bases, methylene linkages as
Triazines or Oxazolidines, methylene bridge condensates, and other impurities.
Primary constituents: of ethanolamine
1. 1,3,5 Triazine-1,3,5 (2H, 4H,6H) triethanol
Oxazolidine
CAS # 4719-04-4
CAS # 504-76-7
1. Trimethylene glycol Monomethyl ether
2. Dimethylethanolamine
3. Acetamide, N (2-hydroxyethyl)
CAS # 1589-49-7
CAS# 108-01-0
CAS # 142-26-7
Formaldehyde polymers (polyoxymethylene)
The primary constituents are present as shown or as mixtures in equilibrium with the methylol or Schiff forms,
as these reactions are run as solution combination and not as dehydrating (water removal).
The reaction can be run with tertiary amines but forms quaternary type bases, which are very alkaline and
unstable.
HANDLING:
Formaldehyde is easily handled and monitored due to its odor and low level of detection. Suitable method
should be set to specifically identify any low level presence.
Adequate cleaning of any possible spills should be available separate from all other containment systems.
Ethanolamine/water mixture rapidly destroys small quantities of formaldehyde. Sodium or Ammonium
Bicarbonate assist in handing large spills. Formaldehyde is acidic about 3.5 to 6.5 pH, depending on free
acid present.
Trace contaminants can cause excessive changes in final product distribution, and especially insoluble
residue polymers, not easy to remove, causing suspended particles and turbidity.
Formaldehyde should be stored under pressure or in equalization of water or amine or bicarbonate
scrubber at < 110 F if possible, and > 45 F. At lower temperatures the appearance and settling of
paraformaldehyde, should be dispersed prior to use.
The use of the higher 12-15% methanol inhibited grade can be helpful, but the 7% grade is preferred.
Warming of formalin prior to use is not required.
The most common linkage is methylene bridge to produce the Triazines, oxazolidines, Schiff bases, methylol
adducts all commonly called amine aldehyde adducts. Most common adjunct additives are formaldehyde,
acetaldehyde. Acetadol.
Amines vary but are as such:
Acetaldehyde ammonia, alkyl amines and polyamines, hydroxyalkylamines, and ether amines.
H2S Scavenger Series
Impurities:
Specialty Chemical Manufacturing, Marketing, & Distribution
STORAGE, REACTION, and STRUCTURE of H2S SCAVENGERS
15TH AUGUST 2010
STORAGE:
Preferably store liquid H2S scavengers by controlling the temperature at 105 +/- 10 F. Storage above these
temperatures need to be stabilized blends.
Keep the storage from direct light if a drum or tank. If Totes are used and are transparent keep from any
Ultraviolet Light. Maintain a positive pressure against tank vapor outlets to inhibit breakdown and release of
any aldehydes, especially odors.
STRUCTURES:
Comments:
Triazines are an unstable form. Normally it has been assumed that Oxazolidine or Triazines are the color
constituents. The color constituents are deemed results of oxidation and heat. If the triazine exists then
assume it is a formyl [2, 4 6- formyl-1, 3, 5-hydroxyethyl-1, 3, 5-S-triazine (with the 1:1 molar reaction ratio.)]
Diimines are very possible. These are the Schiff bases or the similar to even though we are talking of
tautomer forms.
The imines or enamines of tautomers (C=N or C=C), acetals, hemi-Acetals, and amine/acetals, or dimers or
polymers (i.e. multimer).
Patent by Pounds and Cherry claim the product composition of glyoxal and amines are unknown, no triazines
or imines are present (WO1996005907).
Weers identifies reaction species are methylene bridge materials.
REACTION:
The reaction of the imines, Schiff bases, enamines, Aldehydes, Triazines, oxazolidines, Acetals,
hemi-acetals, and the new coined term of methylene bridged reaction products are through the –
CH2--, methylene group.
Therefore the amine is the absorbing agent or capturing agent.
It is known that the excess amine is not required for effective reaction. Currently Ethanolamine Triazines are
mixed 50% with formalin and increase reaction by 2 times.
Early products of industry used formalin with about 2 to 9% volume of diethnaolamine, triethanolamine,
hydroquinone and others.
So the methylene reacts with the H2S , mercaptan, or other sulfur compounds and the amine is liberated.
H2S Scavenger Series
The color of material should be colorless to a faint yellowish tint.
Specialty Chemical Manufacturing, Marketing, & Distribution
STORAGE, REACTION, and STRUCTURE of H2S SCAVENGERS (cont.)
15TH AUGUST 2010
COMPOSITIONS:
SO WHAT IS THE MOST EFFECTIVE H2S SCAVENGER?
Simply:
1. Methylamine=CH3NH2
2. 1, 3, 5 S-triazine= (CH2)3[CH3N] 3
3. 1, 3, 5-hydroxyethyl-1, 3, 5-S-triazine
4. Acetaldehyde ammonia trimer (CH3CH) 3 (NH) 3
5. [2, 4, 6-formyl-1,3,5-hydroxyethyl-1,3,5-S-triazine],
The reactant activity is assume as 2 for 1
since one methylene and one aldehyde, so EQ= 50.5
6. (2:1 molar amine/Ethanedial) [HOCH2CH2N]2=CH-CH=,
7. Ethylene diamine = [H2C=NCH2CH2N=CH2] ,
Aldehyde
Product Activity %
MW = 31.
MW = 129, trimer, EQ= 29
MW = 219, trimer, EQ= 73
MW =129, trimer, EQ=43
MW= 303, trimer, EQ=101
MW=144, dimer,EQ=72
MW=84, dimer, EQ= 42.
%
Active
Reaction
EQ
Ratio
MeAm/CH2O
MeAm/CH2O
NH3/CH2O
MEA/CH2O
MEA/CH2O
37
50
50
37
50
27
31
36
49
57
31
31
29
73
73
115
100
81 *
149
128
MEA/CH2O
CH3CH2/NH3
MEA/GLY (1:1)
MEA/GLY (2:1)
EDA/CH2O (2:1)
EDA/CH2O (2:1)
93
100
40
40
37
50
72
69
34
71.5
48
57
73
43
50.5
72
42
42
101
62
148.5
101
87.5
74
*not reproducible with anhydrous ammonia.
#4 and #8 compare, meaning, versus a standard MEA triazine that is 1:1 MEA to formalin.
H2S Scavenger Series
The smallest and least hindered molecule.
Specialty Chemical Manufacturing, Marketing, & Distribution
SULFUR IN OIL PROPOSAL
AUGUST 14TH 2010
Sulfur is non polar.
Sulfur is dissolved or chemisorbed into crude oil.
Sulfur in molecules is normally:
•
Sulfur in the (-2) oxidation state
•
Sulfur dioxide
•
Mercaptans as methyl, ethyl, propyl, aryl and others as linear or branched thiols)
•
H2S -reduced
•
SO4(sulfates)
•
Dimethyl sulfide, diethyl sulfide, methyl ethyl sulfide & other dialkyl sulfides
•
RS-SR (disulfides).
•
•
•
•
•
Carbonyl sulfide
Carbon disulfide
Thiophenes
Benzothiophenes
Ionic polysulfides
What is the per cent of S8?
Sulfur is soluble @ 50% in carbon disulfide (CS 2).
Sulfur is soluble @ 2.5% in acetone.
A desalting process offers the advantage of using NaOH or KOH with the washing action.
Also the proper surfactant can be used.
Possibly an oil dispersible aldehyde can react with the caustics, lithium, sodium, or potassium to form the
sugars or carbohydrates insitu.
An oxidizer may be included in a wash step and convert mercaptans to dialkyl disulfides. Drawback is dialkyl
sulfides will not remove by this method. US patent 3,449,239.
A relatively standard method is to dissolve sulfur with strongly alkaline Na2S to form Na2S2. The sulfur exists
in chains terminating with negative charges. Acidification of such a solution yields a mixture of hydrogen
polysulfides (sulfuranes) and chain compounds that will decompose to sulfur and hydrogen sulfide.
Dialkyl disulfides (C4 to 22 carbons) [Merox are normal] with amine (4 to 12 carbons) additive as
Diethylamine or N-alkyl-1, 3-propane diamine. US patent 4,239,630.
Sulfur reacted disulfide. 15.5 lbs. sulfur per barrel solvent @ 75F. US patent 3,531,160.
NMP and M-Pyrol will reduce films and disrupt crystal liquid interface.
Sulfur is soluble in M-Pyrol. H2S is soluble in M-Pyrol @ 32 volumes.
Maltose is a stabilizer for polysulfides.
Sodium Borohydride reacts with disulfides; will hydrogenate double bonds or nitriles.
Triethylamine [Et3N]-pyridine. [0.11/0.89]. High solubility of H 2S.
Sulfur is 30 times less soluble in ethanol than in pyridine at 20C. “McGill Univ. Montreal, Quebec”.
H2S Scavenger Series
Samples of solids extracted from oils can be subjected to magnet to see if associated Fe will separate. Apply
the magnet direct to the crude oil.
Specialty Chemical Manufacturing, Marketing, & Distribution
SULFUR IN OIL PROPOSAL (cont.)
Amines. Chemical solvents. Solvent absorption.
Methyl Amine. CH3NH2. Available as 40% solution.
MDEA. Methyldiethanolamine.
MDEA oligimers. DNP-02-00-2900.
MEA. Monoethanolamine.
DEA. Diethanolamine
THEED. MDEA dimer (trihydroxyethyl ethylene Diamine).
BHEED. Bis (hydroxyethyl) Ethylenediamine.
DMEA. Dimethylaminoethanol reacts with H2S.
DMIPA.Dimethylisopropanolamine, neutralizes HCl and is not affected by H 2S making it a neutralizer
In sour crude or overheads. [patent by Betz Laboratories]
TEA. Triethanolamine will not improve contact with H 2S, COS, RSH, RS-SR, reactive sulfur, other
organic sulfides.
Piperazine.
Diethylethanolamine.
1-formylpiperdine. With M-Pyrol (Purisol process)
Alkanolamines are unable to absorb dialkyl sulfides, since the lack of an acidic proton. Alkanolamines
are very inefficient in absorbing thiols (mercaptans)
• Ethers. Dialkyl ethers of polyethylene glycols, Selexol. US patent 4,336,233.
• Polyalkylene glycol and polyalkylene glycol ethers. US patent 5,582,714.
Washing the extracted hydrocarbons.
Diethylene glycol and triethylene glycol-to remove sulfur compounds, oxygenates, and C4-C6 olefins.
US patent 5,689,033.
Amine Ethoxylates. EO-fatty amine. Improves contact with H 2S, COS, RSH, RS-SR, reactive sulfur,
and other organic sulfides.
Example-2:2:1; Fe, Fe/Cu, Zn; EO-NR, H2S.
Dienes. Cyclopentadiene is soluble in CS2 and polymerizes to dicyclopentadiene.
Olefin-Amine: US patent 5,567,212 and 5,567,213
Produce an aldol condensation-aldimine or aldolimine. Produce unsaturated ketone or aldehyde.
Prefer amine not > 4 carbons. Amine is primary. Prefer amine has an alcohol group.
Scavenges H2S and sulfur. Operates by insertion into the double bond (olefinic).
H2S Scavenger Series
AUGUST 14TH 2010
Specialty Chemical Manufacturing, Marketing, & Distribution
SULFUR IN OIL PROPOSAL (cont.)
AUGUST 14TH 2010
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Butyl formcel (Celanese)-53% butanol, 40% formaldehyde, 7% water.
Ethylene glycol hemiformal= 1,6-dihydroxy-2,5-dioxahexane US Patent 7078005
DMAPA + paraformaldehyde.
DNBA + paraformaldehyde, less reacted=precursor to methyl di-n-butylamine, bis-di-n-butyl
menthane. Contains free CH2O oligimers. DNP-02-00-2601
Cyanuric acid. Acidic phenolic alcohol-aldehyde. Used in swimming pools and also chlorine
derivatives. Melamine will precipitate it.
DNP-02-00-2333 EDA/formalin
DNP-02-00-2301 EDA/MEA/CH2O triazines
Hexamethylol melamine. Melamine + formaldehyde.
Hydantoin-glycol urea. Imidazolinedione
DMDM Hydantoin.
Bridged methylene polyamines (not Triazines). See US patent 5,284,576. Does not list sulfur.
Bridged methylene polyamines under non-dehydrating conditions. US patent 6,024,866.
Does not list sulfur.
Gamma-butyrolactone(BuL)
Formaldehyde, 37%.
Stabilized CLO2.
1. Make a solution of 80% sodium chlorite of 31.25% to equal 25% solution.
Dilute this stock solution before field use.
Bleach: sodium hypochlorite 7.5 to 12.5 % soln.
Metal Chelates: Fe, Cu, Co, Mn, Cr, V, Zn
Or also Ru, Os, Rh, Ir, Ni, Pd, Pt, Ag, Au, Cd, Hg, Al, Ga, In, Tl, Ge, Sn, Pb, Sb, and Bi.
Surfactants to assist these: alkyl, Hydroxyalkyl, quaternary ammonium, polyether, phenol, alkyl phenol,
ethoxylated phenol, amino compounds, carboxylic acids and their salts, and sulfonic acid salts. See US
patent 6,531,103.
H2S is converted to sulfur directly by passing through solution of Fe (III) EDTA.
Fe (III) EDTA- + [O] + H2S= Fe (EDTA) (=) + H2O + S|
Note the oxygen is needed.
Also shown is:
H2S + 2 Fe [+3] = S (0) + 2 Fe (2+) + 2 H (+)
Possibly Erythorbic acid in ammonium bisulfite to inhibit oxidation and to chelate the Fe.
Iron sulfide clusters in polar solvents are [4Fe-4S], [3Fe-4S], and [4Fe-2S], in nonpolar are [8Fe-7S].
Glyoxal: dimer aldehyde, typical 40% solution in water. Used by Clariant and Servo.
See US patent 4,680,127.
H2S Scavenger Series
Aldehydes and Aldehyde reaction products:
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SULFUR IN OIL PROPOSAL (cont.)
AUGUST 14TH 2010
Reactive groups:
Alpha olefin epoxides (glycidols), varying chain lengths, including epichlorohydrin. Ethylene imines.
Buffered Sodium Nitrite: Sodium Nitrite has been used in Exxon/NL Sulfa check. Normally used in towers.
Now finds use as for continuous injection. See US patent 4,515,759.
Carbon Disulfide:
With surfactant, DNP-03-00- 3050. CS2 is heavier than water.
Quaternary Benzyl Ammonium Chloride in US patent 5,744,024.
This discloses the Methylamine Triazine using 5 to 10% QAC.
Best is Cocodimethyl like DNP-08-00-8080. Also is Soya dimethyl like DNP-09-00- PS9.
Surfactant Anionic type:
SLS-sodium lauryl sulfate.
SLES-sodium lauryl ether sulfate.
Possible solvent group are formamides:
•
Formamide
•
N-methylformamide
•
N,N-dimethylformamide
•
•
•
•
•
•
•
•
•
•
Solvents: aromatic hydrocarbon
Alkyl naphthalene mixture containing 70-90% C1-C4 napthalenes, 5-15% higher boiling napthalenes,
contains no more than 10% weight of naphthalene.
Has IBP of 230C, flash point > 101C, freeze point< 0C.
US patent 4,322,307.
Alkali, ammonia, or amine solutions with H2S form sulfides and bind elemental sulfur as polysulfide.
Surface active agents added to improve sulfur binding properties.
German patents.
Liquid hydrogen sulfide US patent 3,393,733.
Carbon disulfide Canadian patent 771,129.
Organic sulfides and disulfides.
Extraction with oils and then “W ASH” with alkali hydrogen sulfide solutions or Alkanolamine solutions.
In this procedure, surface active substances are used as emulsion breakers and to facilitate the transfer of
sulfur from the organic phase into the aqueous phase. German patent 2,707,057.
•
Do not use benzene, toluene, xylene, kerosene, or diesel oil.
•
Dimethyl sulfoxide. DMSO.
•
Thiourea.
•
Borated Thiourea, amine salt.
Due to strange nature or density of solids and variable composition, the use of ether amine tetraphosphonic
acid is recommended to polarize the iron and break the bonded sulfur. The acid for is DNP-06-00- 68461,
sodium salt, pH of 4 is 68441, and ammonium salt, pH of 7 is 68561.
H2S Scavenger Series
Surfactant Cationic type:
H2S Scavenger Series
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LOWEST MOLECULES
CH4
Simplest hydrocarbon
of natural gas
Oxygenated methane
alcohol of methane ( +O)
Dehydrogenated methanol (-2H)
METHANOL
CH3OH
FORMALDEHYDE
HCOH or
INHIBITED
CH2O
HCOH /
30 TO 55% HCOH with
FORMALIN
CH3OH
7 to 35% CH3OH
REACTIVE SOLUTION
Water :
H2O or HOH
Hydrogen : H2S or HSH
Sulfide
HS-
always H+ & OHlow pH H2S (molecular)
neutral pH
H+ +
high pH
2H
+
+ S2
-
H2S Scavenger Series
METHANE
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REACTION MECHANISM
Ideal structure:
HOCH2NH2
(formaldehyde plus Ammonia)
Do not capture.
Hexamine is mixture of Ammonia / Formaldehyde oligimer.
4 moles
6 moles
TYPICAL REACTION PRODUCTS of AMINE/ALDEHYDE
RNH2 + CH2O
RNHCH2OH
alcohol, amine
methylolated amine
or R’CHO
R – N = CH2
- H2O
SCHIFF BASE / IMINE
hexahydrotriazine
trimethylene triamine
H on carbon might be methylated (CH 3) with excess formaldehyde
H2S Scavenger Series
Reactivity of Buffered or Amine / Aldehyde Condensates
Reactive side is (CH2) methylene, not CH2O, or the R groups however large.
Only if R groups contain multi-CH2 groups
Aldehyde does not have to be completely reacted to obtain optimum results
Early products were formaldehyde with small buffer quantities of MEA, DEA, TEA,
Morpholine residues or Soda Ash (Na2CO3)
Buffers delay or alter voluminous production of trithiane.
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H2S
REACTIONS with AMINE/ALDEHYDE CONDENSATES
R - NHCH2OH + H2S R - NHCH2SH
Thioalcohol or / Mercaptan
R – N = CHSH
unstable
cyclic polysulfides
C – (S – C) x
(C – S) x
C–S–C–S–C
linear polysulfides
H2S SCAVENGERS CORE PRODUCTS
DNP-02-00-2022
HOCH2NHCH2CH2OH / [ CH2NCH2CH2OH ]3
DNP-02-00-2033
CH3NHCH2OH/[CH3NCH2]3
DNP-02-00-2110
[ R N – CH2 ] 3
DNP-02-00-2301
R1 – NH – R – NHCH2 – NHCH2CH2OH
DNP-02-00-2431
HOCH2NHCH2CH2OH / H2NCH2CH2OH
DNP-02-00-2601
[ CH3 – (CH2)X ] Y N – R Z
H2S Scavenger Series
R–N=C=S
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H2S SCAVENGER TREATMENT PROBLEMS
14TH AUGUST 2010
Watch system variations:
Dew point
Gas composition
Production, gas rate
Condensate
Oxygen
Triazine:
• The conversion from the semi-stable methylene forms or Schiff base or imine to a Triazine can
•
occur or does when admixed with water..
Does methanol addition slow this?
It slows any transition.
Premature change of fluids. Cause:
•
•
•
•
Is there an appearance or change in reaction products?
Is there any FexSx present?
Is there any air or oxygen changing the result?
Any polysulfides? S-CH2-S-CH2-S or S-S-S?
H2S Scavenger Series
•
•
•
•
•
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FORMADELHYDE
Very reactive
Does not Bioaccumulate
Does not remain in the environment
Reacts with alkali “controlled” to carbohydrates, 3 to 6 carbon hydroxy, aldehyde terminated
sugars.
Reacts with amines in excess to form methylated (CH 3) amines
Reacts with H2S to form trithiane
Reacts with Mercaptans
SIMPLY
COLORLESS
IS
EXCELLENT
YELLOW
IS
VERY GOOD
ORANGE
IS
GOOD
RED
IS
FAIR
PURPLE
IS
POOR
As color increases, the consumption and the reaction time increase. Product is
then stable to acid and heat. Will scavenge H 2S in acid.
H2S Scavenger Series
Reacts with alkali “controlled” to alkali formates (salts) generate methanol by-product.
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MOLECULAR WEIGHT AND ACTIVITY
DNP
Molecular
Weight as
2022
219
80%
273
2411
219
52%
421
2033
129
45%
287
REACTIVE COMPARISON
Product #
2022
2411
2033
#/Product per
Ratio
#/H2S
1:01
4.13
2:01
8.26
1:01
5.00
2:01
10.00
1:01
3.00
2:01
6.00
3:01
9.00
H2S Scavenger Series
Product# Nominal Activity Molecular
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RULES OF THUMB FOR H2S SCAVENGING FACTOR
AUGUST 14TH 2010
Below the ratio of chemical used in ppm ratio of volume to mole ppm H 2S is listed. The factor is
the number required to fit the equation for direct calculation.
Ratio
Per ppm
H2S
Factor Liters
Gallons
25
0.25
95
25
water, low mix
11.89
0.1189
45
11.89
high fluid O/W
7.93
0.0793
35
7.93
high H2S
6.3
0.063
24
6.3
6.08
0.061
23
6.08
5.8
0.058
22
5.8
4.76
0.048
18
4.8
towers
4
0.04
15
4
using CH2O in blend
2.11
0.021
8
2.11
lowest known
gals/dayH2S scavenger =
factor x 0.01 x MMscfgas x ppmH2S
typical injection
H2S Scavenger Series
Chemical (0.01)