DNP 2000 - H2S Scavenger Series - Information

H2S Scavenger Series

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

condensates

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 Scavenger Schiff base

DNP-02-00-2800 Liquid KCL Substitute Ammonium salt of an Organic Acid (70-75%)

DNP-02-00-2810 Defoamer Concentrate High molecular weight alcohol based defoamer/

Antifoamer

DNP-02-00-2815 Defoamer Conventrate 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%)

Anthony M. LatorreImage



Direct N-Pakts H2S Scavenger Properties DNP Density ~ Content Application Soluble

Product Active % #/gal 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



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.

These hydrogen sulfides can be removed from the gaseous, hydrocarbon liquid, or water phases by direct treatment into the flow stream.

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

Name

At 20 C Density Aldehyde to Amine

Ratio

active

% by weight free

amine T water MEOH

pH

g/cc #/gal

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 0 10 -11.5

2064 1.12 9.3 1 to 1.13 67 5.77 67 30.22 1.83 10.5-12.0

2100 0.9 7.5 1:01 98



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 gas occurs in wet forms in sewage drains, holding pits, and plants at toxic levels, generated from decomposition of fecal matter.

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.




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 supplies both chemicals and technical expertise in handling of chemicals and their applications. Direct N-Pakt can supply specialty blends for particular use.

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 FexSx.

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 CO2 (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 H2S 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-Pakts 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 FexSx.

Formaldehyde can be added to the Direct N-Pakt line of H2S scavengers except the oils soluble; 2100, 2601, or 2835, to synergize or accelerate reaction ratios.

The use of Direct N-Pakts 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 H2S.

Technical information is supplied for the Direct N-Pakts H2S scavengers and their handling.




H2S TREATMENT RATIOS IN VARIOUS EXPRESSIONS AUGUST 13TH 2010

Triazines supposedly react at 1 mole removes 3 moles of Sulfide (not as H2S). 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.

@ 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

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 H2S/MMscfd 1/14=0.0714 x 3.785 = 0.2704 liters/ppm H2S/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




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.

The first question is how they exist:

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/CH2O reaction

product mixed with formaldehyde, if local restrictions or companies allow.. Some have discussed DEA as some improvement. EDA can be used as well.




Most Efficient H2S Scavengers (cont) August 14th 2010

For Line Injections consider as: Towers as well

DNP Soluble In

CH2O Rxn Product

#

CH2, % Gas/Air Hydrocarbons Water

Methylamine 2033 13.84 yes yes yes

MEA 2022 14.28 nil nil yes





MEA/EDA 2301 15.41 slight slight yes

DEA -------- -------- nil slight yes

di-n-butylamine 2601 8.4 yes yes slight

Primene 81-R -------- -------- yes yes slight

Amine 2100 19.4 yes yes slight

37% Formalin -------- 17.27 yes yes yes

MEA 2835 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.




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 CAS # 4719-04-4

Oxazolidine CAS # 504-76-7

Impurities:

1. Trimethylene glycol Monomethyl ether CAS # 1589-49-7

2. Dimethylethanolamine CAS# 108-01-0

3. Acetamide, N (2-hydroxyethyl) 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.




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. The color of material should be colorless to a faint yellowish tint. 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.




STORAGE, REACTION, and STRUCTURE of H2S SCAVENGERS (cont.)

15TH AUGUST 2010

COMPOSITIONS:

SO WHAT IS THE MOST EFFECTIVE H2S SCAVENGER?

Simply: The smallest and least hindered molecule. 1. Methylamine=CH3NH2 MW= 31. 2. 1, 3, 5 S-triazine= (CH2)3[CH3N] 3 MW= 129, trimer, EQ= 29 3. 1, 3, 5-hydroxyethyl-1, 3, 5-S-triazine MW= 219, trimer, EQ= 73

4. Acetaldehyde ammonia trimer (CH3CH) 3 (NH) 3 MW=129, trimer, EQ=43 5. [2, 4, 6-formyl-1,3,5-hydroxyethyl-1,3,5-S-triazine], MW= 303, trimer, EQ=101

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=, MW=144, dimer,EQ=72 7. Ethylene diamine = [H2C=NCH2CH2N=CH2] , MW=84, dimer, EQ= 42.

Aldehyde % Reaction

Product Activity % Active EQ Ratio

MeAm/CH2O 37 27 31 115

MeAm/CH2O 50 31 31 100

NH3/CH2O 50 36 29 81 *

MEA/CH2O 37 49 73 149

MEA/CH2O 50 57 73 128

MEA/CH2O 93 72 73 101

CH3CH2/NH3 100 69 43 62

MEA/GLY (1:1) 40 34 50.5 148.5

MEA/GLY (2:1) 40 71.5 72 101

EDA/CH2O (2:1) 37 48 42 87.5

EDA/CH2O (2:1) 50 57 42 74

*not reproducible with anhydrous ammonia.

#4 and #8 compare, meaning, versus a standard MEA triazine that is 1:1 MEA to formalin.




SULFUR IN OIL PROPOSAL

Sulfur is non polar.

Sulfur is dissolved or chemisorbed into crude oil.

AUGUST 14TH 2010

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.

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 (CS2).

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 H2S.

Sulfur is 30 times less soluble in ethanol than in pyridine at 20C. McGill Univ. Montreal, Quebec.




SULFUR IN OIL PROPOSAL (cont.)

AUGUST 14TH 2010

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 H2S making it a neutralizer In sour crude or overheads. [patent by Betz Laboratories]

TEA. Triethanolamine will not improve contact with H2S, 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 H2S, 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).




SULFUR IN OIL PROPOSAL (cont.) AUGUST 14TH 2010

Aldehydes and Aldehyde reaction products:

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.




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.

Surfactant Cationic type: 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 WASH 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.




LOWEST MOLECULES

METHANE CH4 Simplest hydrocarbon of natural gas

METHANOL CH3OH Oxygenated methane alcohol of methane ( +O)

FORMALDEHYDE HCOH or Dehydrogenated methanol (-2H)

INHIBITED CH2O HCOH /

30 TO 55% HCOH with

FORMALIN CH3OH 7 to 35% CH3OH

REACTIVE SOLUTION

Water : H2O or HOH always H+ & OH-

Hydrogen : H2S or HSH low pH H2S (molecular) Sulfide neutral pH H+ + HS-

high pH 2H+

+ S2-




REACTION MECHANISM

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.

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 RCHO R N = CH2 - H2O SCHIFF BASE / IMINE

hexahydrotriazine trimethylene triamine

H on carbon might be methylated (CH3) with excess formaldehyde


cyclic polysulfides



H2S REACTIONS with AMINE/ALDEHYDE CONDENSATES

R - NHCH2OH + H2S R - NHCH2SH

R N = CHSH

R N = C = S

Thioalcohol or / Mercaptan

unstable

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 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?




FORMADELHYDE

Very reactive

Does not Bioaccumulate

Does not remain in the environment

Reacts with alkali controlled to alkali formates (salts) generate methanol by-product.

Reacts with alkali controlled to carbohydrates, 3 to 6 carbon hydroxy, aldehyde terminated sugars.

Reacts with amines in excess to form methylated (CH3) 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 H2S in acid.




MOLECULAR WEIGHT AND ACTIVITY

DNP

Product# Nominal Activity Molecular

Molecular Weight as

2022 219 80% 273

2411 219 52% 421

2033 129 45% 287

REACTIVE COMPARISON

#/Product per

Product # Ratio #/H2S

2022 1:01 4.13

2:01 8.26

2411 1:01 5.00

2:01 10.00

2033 1:01 3.00

2:01 6.00

3:01 9.00




RULES OF THUMB FOR H2S SCAVENGING FACTOR

AUGUST 14TH 2010

Below the ratio of chemical used in ppm ratio of volume to mole ppm H2S is listed. The factor is the number required to fit the equation for direct calculation.

Ratio

Chemical (0.01)

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 typical injection

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


DNP 2000 - H2S Scavenger Series - Information

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