Claus process
Piles of sulfur produced in Alberta by the Claus process awaiting shipment at docks in
Vancouver, Canada.
The Claus process is the most significant gas desulfurizing process, recovering elemental
sulfur from gaseous hydrogen sulfide. First patented in 1883 by the scientist Carl Friedrich
Claus, the Claus process has become the industry standard.
The multi-step Claus process recovers sulfur from the gaseous hydrogen sulfide found in raw
natural gas and from the by-product gases containing hydrogen sulfide derived from refining
crude oil and other industrial processes. The by-product gases mainly originate from physical
and chemical gas treatment units (Selexol, Rectisol, Purisol and amine scrubbers) in refineries,
natural gas processing plants and gasification or synthesis gas plants. These by-product gases
may also contain hydrogen cyanide, hydrocarbons, sulfur dioxide or ammonia.
Gases with an H2S content of over 25% are suitable for the recovery of sulfur in straight-through
Claus plants while alternate configurations such as a split-flow set up or feed and air preheating
can be used to process leaner feeds.[1]
Hydrogen sulfide produced, for example, in the hydro-desulfurization of refinery naphthas and
other petroleum oils, is converted to sulfur in Claus plants.[2] The overall main reaction equation
is:

2 H2S + O2 → S2 + 2 H2O
In fact, the vast majority of the 64,000,000 metric tons of sulfur produced worldwide in
2005 was byproduct sulfur from refineries and other hydrocarbon processing plants. [3] [4]
[5]
Sulfur is used for manufacturing sulfuric acid, medicine, cosmetics, fertilizers and
rubber products. Elemental sulfur is used as fertilizer and pesticide.
History
The process was invented by Carl Friedrich Claus, a chemist working in England. A British
patent was issued to him in 1883. The process was later significantly modified by a German
company called IG Farben[6]
Process description
A schematic process flow diagram of a basic 3-reactor (converter) Claus unit is shown below:
Schematic flow diagram of a straight-through, 3 reactor (converter), Claus sulfur recovery unit.
The Claus technology can be divided into two process steps, thermal and catalytic.
Thermal step
In the thermal step, hydrogen sulfide-laden gas reacts in a substoichiometric combustion at
temperatures above 850 °C [7] such that elemental sulfur precipitates in the downstream process
gas cooler.
The H2S content and the concentration of other combustible components (hydrocarbons or
ammonia) determine the location where the feed gas is burned. Claus gases (acid gas) with no
further combustible contents apart from H2S are burned in lances surrounding a central muffle
by the following chemical reaction:
2 H2S + 3 O2 → 2 SO2 + 2 H2O
(ΔH = -4147.2 kJ mol-1)
This is a strongly exothermic free-flame total oxidation of hydrogen sulfide generating sulfur
dioxide that reacts away in subsequent reactions. The most important one is the Claus reaction:
2 H2S + SO2 → 3 S + 2 H2O
The overall equation is [5]:
10 H2S + 5 O2 → 2 H2S + SO2 + 7/2 S2 + 8 H2O
This equation shows that in the thermal step alone two-thirds of the hydrogen sulfide is
converted to sulfur.
Gases containing ammonia, such as the gas from the refinery's sour water stripper (SWS), or
hydrocarbons are converted in the burner muffle. Sufficient air is injected into the muffle for the
complete combustion of all hydrocarbons and ammonia. The air to the acid gas ratio is
controlled such that in total 1/3 of all hydrogen sulfide (H2S) is converted to SO2. This ensures a
stoichiometric reaction for the Claus reaction in the second catalytic step (see next section
below).
The separation of the combustion processes ensures an accurate dosage of the required air
volume needed as a function of the feed gas composition. To reduce the process gas volume or
obtain higher combustion temperatures, the air requirement can also be covered by injecting
pure oxygen. Several technologies utilizing high-level and low-level oxygen enrichment are
available in industry, which requires the use of a special burner in the reaction furnace for this
process option.
Usually, 60 to 70% of the total amount of elemental sulfur produced in the process are obtained
in the thermal process step.
The main portion of the hot gas from the combustion chamber flows through the tube of the
process gas cooler and is cooled down such that the sulfur formed in the reaction step
condenses. The heat given off by the process gas and the condensation heat evolved are
utilized to produce medium or low-pressure steam. The condensed sulfur is removed at the gas
outlet section of the process gas cooler.
A small portion of the process gas can be routed through a bypass inside of the process gas
cooler, as depicted in the here above mentioned figure. This hot bypass stream is added to the
cold process gas through a three-way valve to adjust the inlet temperature required for the first
reactor.
The sulfur forms in the thermal phase as highly reactive S2 diradicals which combine exclusively
to the S8 allotrope:
4 S2 → S8
Side reactions
Other chemical processes taking place in the thermal step of the Claus reaction are [5]:

The formation of hydrogen gas:
2 H2S → S2 + 2 H2
(ΔH > 0)
CH4 + 2 H2O → CO2 + 4 H2

The formation of carbonyl sulfide:
H2S + CO2 → S=C=O + H2O

The formation of carbon sulfide:
CH4 + 2 S2 → S=C=S + 2 H2S
Catalytic step
The Claus reaction continues in the catalytic step with activated aluminum(III) or titanium(IV)
oxide, and serves to boost the sulfur yield. More hydrogen sulfide (H2S) reacts with the SO2
formed during combustion in the reaction furnace in the Claus reaction, and results in gaseous,
elemental sulfur.
2 H2S + SO2 → 3 S + 2 H2O
(ΔH = -1165.6 kJ mol-1)
This sulfur can be S6, S7, S8 or S9.
The catalytic recovery of sulfur consists of three substeps: heating, catalytic reaction and
cooling plus condensation. These three steps are normally repeated a maximum of three times.
Where an incineration or tail-gas treatment unit (TGTU) is added downstream of the Claus
plant, only two catalytic stages are usually installed.
The first process step in the catalytic stage is the gas heating process. It is necessary to prevent
sulfur condensation in the catalyst bed, which can lead to catalyst fouling. The required bed
operating temperature in the individual catalytic stages is achieved by heating the process gas
in a reheater until the desired operating bed temperature is reached.
Several methods of reheating are used in industry:




Hot-gas bypass: which involves mixing the two process gas streams from the process
gas cooler (cold gas) and the bypass (hot gas) from the first pass of the waste-heat
boiler.
Indirect steam reheaters: the gas can also be heated with high-pressure steam in a heat
exchanger.
Gas/gas exchangers: whereby the cooled gas from the process gas cooler is indirectly
heated from the hot gas coming out of an upstream catalytic reactor in a gas-to-gas
exchanger.
Direct-fired heaters: fired reheaters utilizing acid gas or fuel gas, which is burned
substoichiometrically to avoid oxygen breakthrough which can damage Claus catalyst.
The typically recommended operating temperature of the first catalyst stage is 315 °C to 330 °C
(bottom bed temperature). The high temperature in the first stage also helps to hydrolyze COS
and CS2, which is formed in the furnace and would not otherwise be converted in the modified
Claus process.
The catalytic conversion is maximized at lower temperatures, but care must be taken to ensure
that each bed is operated above the dew point of sulfur. The operating temperatures of the
subsequent catalytic stages are typically 240 °C for the second stage and 200 °C for the third
stage (bottom bed temperatures).
In the sulfur condenser, the process gas coming from the catalytic reactor is cooled to between
150 and 130 °C. The condensation heat is used to generate steam at the shell side of the
condenser.
Before storage, liquid sulfur streams from the process gas cooler, the sulfur condensers and
from the final sulfur separator are routed to the degassing unit, where the gases (primarily H 2S)
dissolved in the sulfur are removed.
The tail gas from the Claus process still containing combustible components and sulfur
compounds (H2S, H2 and CO) is either burned in an incineration unit or further desulfurized in a
downstream tail gas treatment unit.
Sub dew point Claus process
The conventional Claus process described above is limited in its conversion due to the reaction
equilibrium being reached. Like all exothermic reactions, greater conversion can be achieved at
lower temperatures, however as mentioned the Claus reactor must be operated above the sulfur
dew point (120–150 °C) to avoid liquid sulfur physically deactivating the catalyst. To overcome
this problem, the sub dew point Claus process operates with reactors in parallel. When one
reactor has become saturated with adsorbed sulfur, the process flow is diverted to the standby
reactor. The reactor is then regenerated by sending process gas that has been heated to 300–
350 °C to vaporize the sulfur. This stream is sent to a condenser to recover the sulfur.
Process performance
Using two catalytic stages, the process will typically yield over 97% of the sulfur in the input
stream. Over 2.6 tons of steam will be generated for each ton of sulfur yield.
The physical properties of elemental sulfur obtained in the Claus process can differ from that
obtained by other processes [5]. Sulfur is usually transported as a liquid (melting point 115 °C).
In ordinary sulfur viscosity can increase rapidly at temperatures in excess of 160 °C due to the
formation of polymeric sulfur chains but not so in Claus-sulfur. Another anomaly is found in the
solubility of residual H2S in liquid sulfur as a function of temperature. Ordinarily the solubility of a
gas decreases with increasing temperature but now it is the opposite. This means that toxic and
explosive H2S gas can build up in the headspace of any cooling liquid sulfur reservoir. The
explanation for this anomaly is the endothermic reaction of sulfur with H2S to polysulfane.
Converting Hydrogen Sulfide
by the Claus Process
Hydrogen sulfide (H2S) is a smelly, corrosive, highly toxic gas. Besides its other bad habits, it
also deactivates industrial catalysts. H2S is commonly found in natural gas and is also made at oil
refineries, especially if the crude oil contains a lot of sulfur compounds.
Because H2S is such an obnoxious substance, it is converted to non-toxic and useful elemental
sulfur at most locations that produce it. The process of choice is the Claus Sulfur Recovery
process.
Description of the Claus Process
First the H2S is separated from the host gas stream using amine extraction. Then it is fed to the
Claus unit, where it is converted in two steps:
1. Thermal Step. The H2S is partially oxidized with air. This is done in a reaction furnace
at high temperatures (1000-1400 deg C). Sulfur is formed, but some H2S remains
unreacted, and some SO2 is made.
2. Catalytic Step. The remaining H2S is reacted with the SO2 at lower temperatures (about
200-350 deg C) over a catalyst to make more sulfur.
A catalyst is needed in the second step to help the components react with reasonable speed.
Unfortunately the reaction does not go to completion even with the best catalyst. For this reason
two or three stages are used, with sulfur being removed between the stages. Engineers know how
different factors like concentration, contact time and reaction temperature influence the reaction,
and these are set to give the best conversions.
The reaction is as follows: 2H2S + SO2 ==> 3S + 2H2O
Inevitably a small amount of H2S remains in the tail gas. This residual quantity, together with
other trace sulfur compounds, is usually dealt with in a tail gas unit. The latter can give overall
sulfur recoveries of about 99.8%, which is very impressive indeed.
Sulfur Production by the Claus Process
Process Improvements
Over the years many improvements have been made to the Claus process. Recent developments
include:



SUPERCLAUS (TM).
A special catalyst in the last reactor oxidizes the H2S selectively to
sulfur, avoiding formation of SO2. Significantly higher conversions are obtained at
modest cost.
Oxygen Claus. The combustion air is mixed with pure oxygen. This reduces the amount
of nitrogen passing through the unit, making it possible to increase throughput.
Better Catalysts. Higher activities have been achieved with catalysts that provide higher
surface areas and macroporosity.
More improvements can be expected. Here are some possibilities.
CS2 destruction. Carbon disulfide (CS2) is a side product made in the furnace. Laboratory work
has shown that special catalysts operating in the furnace can destroy the CS2 before it gets into
the catalytic section. A commercially available catalyst like this might be developed for use in a
Claus plant.
Catalyst Temperature Policy. The conversion of H2S goes faster at higher temperatures, but a
more favorable equilibrium is obtained at lower temperatures. It isn't obvious whether higher or
lower temperatures are needed in the third converter. Kinetic modelling may supply the answer,
thereby improving conversion or reducing catalyst replacement cost.
Other Ways to Process Sour Gas
Some H2S-containing gas is unsuitable for treatment by amine extraction because of high CO2
levels. These streams often lend themselves to processing by so-called liquid redox processes
such as SulFerox® or ARI-LO-CAT®. Instead of air, these processes use a liquid solution
containing oxidized iron.
Several novel processes are being developed to make hydrogen as well as sulfur from H2S. These
are sometimes called H2S splitting processes. Hydrogen is a valuable gas that is needed in oil
processing and for the manufacture of ammonia and methanol.
Exploring the Claus Process
There are few processes that have served the chemical industry better than the Claus
Process. For years, this process has helped remove hydrogen sulfide (H2S) gas from combustion
streams and turn it into salable elemental sulfur.
Figure 1: Simplified Flow Diagram of the Claus Process
A gas containing H2S is fed with oxygen to a waste heat boiler. Oxygen is used to help the
boiler reach the
temperature necessary for combustion from 1562 to 2462 0F (850 to
1350 0C). The combustion products are cooled between 500 to 572 0F (260 to 300 0C) and fed
to the catalytic stage of the process. The process gas passes over an Al2O3 based catalyst with a
surface area specification of 200-300 m2/g. The following reaction results:
2 H2S + SO2 ---> 3 S + 2 H2O
The elemental sulfur is drawn off at various locations throughout the process and is sent to
storage. The remaining gases in the process stream are sent to the desulfurization section (not
shown in Figure 1) for further sulfur removal. In the desulfurization section, additional sulfur
removal lowers the concentration of sulfur in the process stream to between 100 and 1000 ppmv
(parts per million by volume). The residual sulfur is then transformed to sulfur dioxide in a
furnace via the following reaction:
S + O2 ---> SO2
Heat in the hot furnace gas is recovered by heat exchange with a portion of the process stream
leaving the desulfurization unit. The cooled, SO2 rich furnace gas is treated in downstream
equipment for SO2 removal. A portion of the heated process stream is recycled to the waste heat
boiler while the balance is vented to the atmosphere.
The Claus Process has been used to produce soot-free sulfur for years due to it's unique dual
chamber combustion compartment. If the feed rate to the Claus plant becomes too low, a
sustaining combustion chamber reaction is necessary to prevent soot from forming.
An interesting aspect of the Claus Process is the strange behavior of molten sulfur. The
temperature of molten sulfur must be controlled carefully. If the sulfur is allowed to cool too
much it can begin to polymerize. Below is the characteristic viscosity curve associated with
molten sulfur.
For further reading about the Claus Process, visit the links below:
Claus process
The Claus process is a catalytic chemical process that is used for converting gaseous hydrogen
sulfide (H2S) into elemental sulfur (S).[1] [2] [3] The process is commonly referred to as a sulfur
recovery unit (SRU) and is very widely used to produce sulfur from the hydrogen sulfide found
in raw natural gas and from the by-product sour gases containing hydrogen sulfide derived from
refining petroleum crude oil and other industrial facilities.
There are many hundreds of Claus sulfur recovery units in operation worldwide. In fact, the vast
majority of the 68,000,000 metric tons of sulfur produced worldwide in 2010 was by-product
sulfur from petroleum refining and natural gas processing plants.[4]
Feed gas composition
Claus unit feed gases have a wide range of compositions. Most of the feed gases are originate
from absorption processes using various solvents to extract hydrogen sulfide from the by-product
gases of petroleum refining, natural gas processing, tar sands processing, coal gasification,
smelters, coke ovens and other industries. The absorption processes used for that purpose include
Amine gas treating, Rectisol and Selexol to name a few.
In addition to hydrogen sulfide extracted from by-product gases by an absorption process,
petroleum refineries also derive hydrogen sulfide from the steam distillation of wastewaters
containing dissolved hydrogen sulfide. Those wastewaters are referred to as sour water and the
steam distillation of those wastewaters is referred to as sour water stripping.
The table below provides typical analyses of the Claus feed gases obtained from amine gas
treating and from sour water stripping:
Gases with an H2S content of over 25% are suitable for the recovery of sulfur in straight-through
Claus process units (as described in the next section). Other process design configurations can be
used to handle gases with lesser amounts of H2S.[5]
The amount of hydrogen sulfide derived from sour water stripping in a petroleum refinery is very
much less than is derived from the refinery's amine gas treating facilities.
Schematic flow diagram and description
A Claus process plant
The Claus reaction to convert H2S into elemental sulfur requires the presence of one mole of SO2
for each two moles of H2S:

(1) 2H2S + SO2 → 3S + 2H2O
To provide that ratio of components, the first step in the Claus process is the combustion of onethird of the H2S in the feed gas:

(2) H2S + 1.5 O2 → SO2 + H2O
Combining equations (1) and (2), the overall process reaction is:

(3) 2H2S + O2 → 2S + 2H2O
As shown in the schematic diagram below, the feed gas to a Claus process unit is burned in a
reaction furnace using sufficient combustion air to burn only one-third of the H2S it contains.
That is accomplished by using a flow ratio controller to provide the required ratio of combustion
air to feed gas.
The reaction furnace pressure and temperature is maintained at about 1.5 bar gauge (barg) and
about 1,000 °C. At those conditions, the Claus reaction occurs thermally in the reaction furnace
(i.e., without requiring any catalyst). About 70% of the H2S in the feed gas is thermally
converted into elemental sulfur in the reaction furnace.
The hot reaction product gas, containing gaseous sulfur, is used to produce steam in a boiler
(called a waste heat boiler) which results in cooling the gases. The gas is then further cooled and
condensed in a heat exchanger while producing additional steam. The condensed liquid sulfur is
separated from the remaining unreacted gas in the outlet end of the condenser and sent to product
storage.
The separated gas is then reheated and enters the first catalytic reactor maintained at an average
temperature of about 305 °C where about 20% of the H2S in the feed gas is converted into
elemental sulfur. The outlet product gas from the first reactor is cooled in another condenser
while also producing steam. Again, the condensed liquid sulfur is separated from the remaining
unreacted gas in the outlet end of the condenser and sent to product storage.
The separated gas from the second condenser is sent to another reheater and the sequence of gas
reheat, catalytic reaction, condensation and separation of liquid sulfur from unreacted gas is
repeated for the second and third reactors at successively lower reactor temperatures. About 5%
and 3% of the H2S in the feed gas is thermally converted into elemental sulfur in the second
reactor and third reactors, respectively. For a well-designed and operated Claus sulfur recovery
plant having three catalytic reactors (as shown in the flow diagram), an overall conversion of at
least 98% can be achieved. In fact, the latest modern designs can achieve up to 99.8% conversion
of hydrogen sulfide into product sulfur that is 99+% saleable "bright yellow sulfur".
The remaining gas separated from the last condenser is referred to as "tail gas" and is either
burned in an incinerator or further desulfurized in a "tail gas treatment unit" (TGTU).
Reheat methods
The various methods used for the reheating required upstream of each catalytic reactor include:



Direct gas-fired heaters using fuel gas and designed to operate at sub-stoichiometric
conditions to prevent any oxygen (O2) from getting into the reactors which can damage
the catalyst.
Gas-to-gas heat exchangers in which cooled gas from a condenser exhanges heat with the
hot gas from the upstream reactor.
Steam-to gas heat exchangers in which the cooled gas from a condenser is heated with
high-pressure steam.
Other design features
Older Claus sulfur recovery units were designed using only two catalytic reactors. Such units
will typically convert only about 97% of the H2S in the feed gas. Because of stringent
environmental regulatory requirements in the United States as well as many other nations, many
of those older units have been upgraded to include three reactors. The tail gas from those that
have not been upgraded is very probably desulfurized further in a tail gas treatment unit.
When the feed gas to a Claus unit includes ammonia and hydrocarbons (such as in the overhead
gas from a petroleum refinery sour water stripper), special designs of the reaction furnace burner
are available to provide complete combustion of those feed gas components.
To obtain higher reaction furnace temperatures and/or reduce the gas volume to be processed,
pure oxygen may be used to enrich the reaction furnace combustion air.
Catalyst
The catalytic reactors each contain a bed of catalyst with a depth of about 90 to 120 cm. The
most widely used Claus reaction catalyst is porous aluminum oxide (Al2O3), commonly referred
to as alumina.[6] [7]
The alumina catalyst owes its activity to a very high surface area of 300 m²/g or higher. About 95
% of that surface area is provided by pores having diameters of less than 8 nm (80 angstroms).
The catalyst not only increases the kinetics (i.e., the rate of reaction) of the Claus reaction
equation (1), but it also hydrolyzes the carbonyl sulfide (COS) and carbon disulfide (CS2) that is
formed in the reaction furnace:


(4) COS + H20 → H2S + CO2
(5) CS2 + 2H20 → 2H2S + CO2
The H2S formed as per the hydrolysis equations (4) and (5) is then converted into elemental
sulfur as per the Claus reaction (1). Most of the hydrolysis occurs in the first Claus reactor.
Other Claus catalysts based on titanium dioxide (TiO2) are also used. The titanium dioxide
catalysts are produced from anatase, one of the three naturally occurring mineral forms of
titanium dioxide. They are also called titania catalysts and are said to be more resistant to
thermal aging than the alumina catalysts. They are also said to have a higher activity for the
hydrolysis of COS and CS2 which allows the first Claus reactor to operate at lower temperatures
compared to alumina catalysts.[8] However, they are significantly more expensive than the
alumina catalysts.
History
In nineteenth century, there were many alkali manufacturing plants in England producing sodium
carbonate (Na2CO3) by the Leblanc process. The original Claus process was developed by Carl
Friedrich Claus, a chemist working in England, for the purpose of recovering sulfur from the
waste calcium sulfide (CaS) generated by the Leblanc process. As a catalyst, he chose a bog iron
ore and later bauxite (a mineral with a high alumina content).[9] In 1883, Claus was granted a
British patent for the process.[10] [11] [12]
During the next 53 years, the Claus process underwent several minor modifications. In 1936, I.G.
Farbenindustrie a (German conglomerate of chemical companies) introduced a modification of
the process that utilized a thermal conversion step followed by catalytic conversion steps, which
is the basically the concept currently used in modern Claus sulfur recovery units.
References
1. ^ J.H. Gary and G.E. Handwerk(1984), Petroleum Refining Technology and Economics,
2nd Edition, Marcel Dekker, ISBN 0-8247-7150-8.
2. ^ Fundamental and Practical Aspects of the Claus Sulfur Recovery Process P.D. Clark,
N.I. Dowling and M. Huang, Alberta Sulfur Research Ltd., Calgary, Alberta, Canada
3. ^ The SuperClaus process
4. ^ Sulfur production report by the United States Geological Survey
5. ^ Gas Processors Suppliers Association(GPSA) (1987), Gas Processors Suppliers
Association Engineering Data Book, 10th Edition, Gas Processors Suppliers Association.
(See Volume II, Section 22)
6. ^ The Role of Claus Catalyst in Sulfur Recovery Unit Performance Terry McHugh, Ed
Luinstra and Peter Clark,presented at Sulphur 98 conference in Tucson, Arizona,
November 1998.
7. ^ Arthur Kohl and Richard Nielson (1997), Gas Purification, 5th Edition, Gulf
Professional Publishing, ISBN 0-88415-220-0.
8. ^ Same as Reference 8
9. ^ Howard F. Rase (2000), Handbook of Commercial Catalysts:Heterogeneous Catalysts,
1st Edition, CRC Press, pp. 240 - 242, ISBN 0-8493-9417-1.
10. ^ Same as Reference 8
11. ^ Same as Reference 10
12. ^ British patent 5,958 (1883)
SWAPSOL in Houston’s Sulphur 2011 Nov. 10 on H2S processing breakthrough
Wednesday, November 9th, 2011
Media Alert
SWAPSOL Corporation tomorrow will present its breakthrough sulfur recovery technology that
can reduce hydrogen sulfide to below detectable levels and yield valuable products in a low
temperature catalytic reaction.
Sulphur
11:50am,
2011
/
Intercontinental
Houston
Thursday,
November
Session:
Stream
A:
Presenter: Wolf Koch, CEO / SWAPSOL Corp.
Sulphur
/
Houston,
10th,
and
TX
2011
Sulphides
The
SWAP:
A
breakthrough
in
hydrogen
sulfide
processing
SWAPSOL is developing commercial processes around a recently discovered chemical reaction,
which reduces hydrogen sulfide (H2S) below detectable levels while reacting with carbon
dioxide (CO2) to form water, sulfur and carsuls, a carbon-sulfur polymer. The SWAP stands to
fundamentally simplify sulfur removal technology as it consumes carbon dioxide in an
exothermic reaction under relatively mild process conditions. Alternatively, hydrogen sulfide
may be reacted to form hydrogen and sulfur. The SWAP will have applications in landfill gas,
sour gas, industrial flue gas cleanup, Claus tail gas cleanup and may serve as an alternative to
Claus technology. A related process allows for the destruction of waste hydrocarbons by reacting
them with sulfur to form hydrogen sulfide and carsuls.
The primary reactions and variants have been independently verified and the chemical kinetics
determined by a third party laboratory. Swapsol has filed US and international patent
applications covering all aspects of the technology. Laboratory scale development of the various
Swapsol processes is nearing completion and the company is exploring opportunities for pilot
plant development programs with potential partners.
For more information:
Evan Howell / [email protected]
SWAPSOL in Hydrocarbon Engineering Magazine on sour gas, landfill gas
cleanup
Wednesday, October 12th, 2011
This month, editors at Hydrocarbon Engineering Magazine, Europe’s premiere
refining trade publication, took a look at the SWAP’s application in cleaning sour gas which has
potential for dramatic savings for refiners. A new outside report shows the SWAP can beat costs
of traditional methods (Claus) by as much as 70 percent.
In early 2011, an independent comprehensive process design and cost analysis was
commissioned for the SWAP sour gas application, covering a design for a typical well and one
for cleaning landfill gases. The outside contractor was chosen because of his renown expertise in
sulfur recovery technology and process design.
“What is clear from the data is that the SWAP can provide cost advantages over competing
processes, especially in view of the fact that thecompeting cost data needs to be inflated for a
four year time period. Compared to the industry standard (the Claus process), the SWAP
provides a cost advantage in excess of 40 % (after adjustments for inflation); the advanced
SWAP process increases the potential advantage to 70%.”
To read the full article, please visit the PDF.
Wolf Koch Named CEO of SWAPSOL
Monday, September 19th, 2011
Former Amoco veteran leads efforts behind industry breakthrough of the SWAP
Wolf Koch before shareholders in NYC, March 2011
The SWAPSOL Board of Directors has named Amoco Oil veteran Wolf Koch president and
chief executive officer of N.J.-based SWAPSOL on the eve of a major expansion of business
development activities by the company.
The new appointment surrounds the company’s patented green chemistry breakthrough, the
SWAP, designed to mitigateCO2 and turnpollutants into valuable materials for a wide range of
industries. Koch is President and Founder of the Sterling-based consulting firm Technology
Resources International, Inc.
Board chairman and company co-founder Ray Stenger said Koch will have responsibility for
business operations, strategy, and partnership negotiations as the company moves forward; he
will divide his time between the Company’s office and labs in Eatontown, N.J. and his Sterling
office.
“We couldn’t have a better man at the helm,” Stenger said. “Wolf’s many years of experience in
the oil industry and his vast network of industry relationships make him the ideal choice in
leading us forward.”
The SWAP is a suite of hydrocarbon refining applications based on a self-sustainable chemical
reaction. The reaction instantaneously eliminates noxious pollutants, such as hydrogen sulfide
and reduces CO2 levels in natural gas and refinery streams. The SWAP has applications in
landfill gas-to-energy projects, hydrogen generation, industrial flue gas cleanup and carbon fiberlike material development. Independent engineering and cost analyses show the SWAP can
reduce costs in some hydrogen sulfide removal operations by as much as 70 percent and
significantly lower a plant’s carbon footprint. SWAPSOL is currently engaging industry on joint
development and joint investment opportunities in the commercialization of the technology.
Koch recently served as Director of Planning and Development for SWAPSOL and is a member
of the company’s Board of Directors. He holds a Ph.D. in chemical engineering and worked in
the oil and gas sector for more than 30 years, including 20 years at Amoco Oil. He frequently
presents on the SWAP to industry both in the United States and abroad, and he will continue
these activities as CEO.
“SWAPSOL is armed with an innovative marketing team and a strong cadre of negotiating
experts,” Koch said. “Backed by independent commercial analyses showing the economic and
environmental benefits of the SWAP, I’m confident industry will embrace our technology’s
potential in the marketplace.”
Tags: Amoco, Claus Process, CO2 emissions, Evan Howell, hydrogen sulfide, landfill gas,
Natural Gas, ray stenger, refining, SWAP, swapsol, Technology Resources International, wolf
koch
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Gastech 2011 – SWAPSOL PROCESS CUTS GAS REFINING COSTS 70
PERCENT
Tuesday, March 22nd, 2011
Low-temp, catalytic process set for Q2 pilot, new partner discussions on horizon
GASTECH /Amsterdam (22 March, 2011) – SWAPSOL announced today its pre-pilot sulphur disposal
technology may help refiners eliminate nearly two-thirds of their current gas processing costs. Company director
Wolf Koch (Cook), Ph.D., cited data from an independent cost and engineering analysis when he presented the news
at Gastech.
SWAPSOL Director, Wolf Koch
“This new data shows how the SWAP can both improve a gas processors bottom line and make a
positive contribution to a cleaner environment simultaneously,” Koch said.
The report shows the SWAP disposal costs estimate to be $0.46 ($/1,000cf), compared to $1.40
($/1,000cf) with current Claus technology. The cost comparison is based against published U.S.
Department of Energy data on competing processes adjusted from 2004 to 2008 – the reference
time frame for the present study.
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Can sulfur recovery breakthroughs reduce our environmental footprint?
Saturday, August 22nd, 2009
There has been a recent discovery of a previously unknown exothermic reaction between CO2
and H2S. It’s a reaction that may fundamentally alter the hydrocarbon industry. Work
continues. It’s called the Stenger-Wasas Process (SWAP) developed by Ray Stenger and Jim
Wasas. And it may make obsolete traditional petroleum methods, such as the Claus Process
and its variants.
The SWAP: Unrefined sour natural gas is fed into the catalytic reactor, where the SWAP
reaction occurs between CO2 and H2S. Refined gas flows past the separator. CO2 and H2S are
converted into water, sulfur and carbon in the collector. In a reaction that can start in less than
one second at very moderate temperatures, the result of the SWAP is refined natural gas.
Brief Overview
Sulfur contaminants such as hydrogen sulfide (H2S), carbonyl sulfide (COS), and mercaptans in
gas streams can create unacceptable levels of sulfur emissions in power applications or poison
catalysts used in chemical synthesis. Sulfur contaminants are usually reduced to less than 300
ppm for power generation and considerably lower (<1 ppm) for the synthesis of methanol,
ammonia, and Fischer-Tropsch (FT) liquids.
Sulfur recovery unit (courtesy: C&I)
Sulfur Recovery Processes
Removing sulfur from a natural gas or syngas process stream is only part of the story. The
residual sulfur present in an acid gas stream must then be recovered to prevent environmental
and safety harms, as well as meet operator permit requirements. Two main technologies have
traditionally been used commercially to recover sulfur: the Claus process (partial combustion)
for high levels of sulfur, and catalytic Redox processes, for relatively low levels of sulfur. In
recent years, bio-chemical based technology, the Thiopaq Process, has been developed and
commercially implemented. Other recent developments include the development of hybrid
processes that combine Claus and Redox technology and are used for tailgas cleanup in Claus
plants.
The SWAP has been verified by gas chromatography in the laboratory to reduce H2S to below
the limit of detection (about 4ppb) in a single pass through the SWAP column.
The SWAP in the laboratory
Classified as hazardous waste by the EPA, H2S disposal requires expensive processing, i.e. the
Claus Process. The SWAP may reduce related capital costs for the H2S disposal resulting from
crude oil desulfurization, while simultaneously eliminating substantial amounts of CO2.
CLAUS PROCESS
Technology Description
In the Claus process, a high H2S concentration stream is the feedstock for recovery to elemental
sulfur. Roughly 1/3 of the H2S is burnt (partial combustion) to form sulfur dioxide (SO2). The
remaining H2S reacts with the synthesized SO2 over an alumina or bauxite catalyst to produce
elemental sulfur. Depending on their concentrations, the unreacted components (tail gas), such as
residual SO2, CO2, and H2S, are either emitted, thermally oxidized, or further treated in an
additional recovery process.
(US Environmental Protection Agency, AP42, 5th Edition, “Compilation of AirPollutant
Emissions Factors Volume 1: Stationary Point and Area Sources, 1995) The Claus process is
thermodynamically limited to ~97 percent sulfur recovery, although additional treatment steps,
such as tail gas sulfur recovery, can increase the recovery rate.
Commercial Manufacturers and Applications
The Claus process is the oldest commercial sulfur treatment process, with development dating
back to the late 19th century. Today, Claus processes are the main step used for elemental sulfur
production worldwide-in fact, 90 percent to 95 percent of the sulfur recovered in the United
States was from the Claus process. Almost 40 companies operate over 1000 Claus processes in
the United States, recovering nearly 9 million tons per year of sulfur. The petroleum and natural
gas industries are the main users of the technology, with IGCC applications making up a small
but growing segment of the user population.
With catalytic refining, environmental footprint and operational costs can be lowered. This and
other breakthroughs may change the landscape of hydrocarbon refining. www.swapsol.com