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Process Solutions for Adsorption, Drying, Purification, Refining and Conditioning of Gases and Liquids.
In 1935, Lectrodryer designed the first hydrogen dryer to maintain appropriate dewpoint for the hydrogen used in the first hydrogen cooled generators. Since then, we have not only set the technology standard for that application but expanded to other auxiliaries within the power plant as well. Our current offerings include:
If you are interested in developing a new system or upgrading your existing auxiliaries, we offer engineering and manufacturing services.
For additional information on the products click here or contact us at info@lectrodryer.com
Some natural gas wells furnish gas of very high purity, that is, almost pure methane. However, most hydrocarbon streams are complex mixtures of hundreds of different compounds. A typical wellstream is a high velocity, turbulent, constantly expanding mixture of gases and hydrocarbons intimately mixed with water vapor, free water, solids, and other contaminants.
Contaminant removal processes can be divided into two groups: dehydration and purification. The principle reasons for the importance of natural gas dehydration include the following:
1. Liquid water and natural gas can form solid ice-like hydrates which can plug valves, piping, etc.
2. Natural gas containing liquid water is corrosive, particularly if it contains CO2 or H2S.
3. Water vapor in natural gas pipelines may condense, causing sluggish flow conditions.
4. Water vapor increases the volume and decreases the heating value of natural gas thus leading to reduced line capacity.
5. Dehydration of natural gas prior to cryogenic processing is a must to prevent ice formation on low temperature heat exchangers.
Of these, the most common reason for dehydration is the prevention of hydrate formation in gas pipelines. Natural gas hydrates are solid crystalline compounds formed by the chemical combination of natural gas and water under pressure at temperatures considerably above the freezing point of water. In the presence of free water, hydrates will form when the temperature is below a certain point called the hydrate temperature.
Hydrate formation is often confused with condensation and the distinction between the two must be clearly understood.
Condensation of water from natural gas under pressure occurs when the temperature is at or below the dewpoint at that pressure. Free water obtained under such conditions is essential to formation of hydrates which will occur at or below the hydrate temperature at the same pressure.
During the flow of natural gas, it is necessary to avoid conditions that promote the formation of hydrates. This is essential since hydrates may choke the flow stream, surface lines, and other equipment. Hydrate formation in the flow stream results in a lower value for measured wellhead pressures. In a flowrate measuring device, hydrate formation results in lower apparent flow rate. Excessive hydrate formation may also completely block flowlines and service equipment.
Thus, the need for prevention of hydrate formation is obvious, and the easiest way to eliminate hydrates is to substantially remove the water from the natural gas stream. The most efficient method for removing the water present in a natural gas stream is by adsorption with a solid desiccant such as molecular sieve or activated alumina.
Another important application for desiccant drying is the liquefaction of natural gas. Methane is converted into a liquid in a cryogenic process at -285°F (-176°C) and atmospheric pressure. There is a 600 to 1 reduction in volume. As a liquid, large volumes of methane can be easily transported and/or stored. Natural gas companies liquefy and store gas (1 to 20 MMSCFD) during low demand periods and use the stored liquid during high periods of demand. Natural gas found in remote areas can be liquefied and transported to places of demand. Because of the low dewpoints needed for the cryogenic production of LNG, dryers are used.
This market covers the drying of air or oxygen to make ozone in sewage treatment plants. Ozone, a strong smelling gas, exists in greatest quantities in the upper layers of the earth’s atmosphere. To exist, it requires a substantial amount of energy, which it gets from the sun.
At normal temperatures and pressure found on the earth’s surface, ozone (O3) is unstable. It decomposes into molecular oxygen (O2) and atomic oxygen (O). Since ozone and atomic oxygen have considerable oxidizing power, this gas becomes a prime choice for eliminating color, taste, odor, bacteria, and viruses from water.
In addition, ozone has numerous advantages over other disinfectants: it leaves no traces; its reactions do not produce toxic halogenated compounds; it acts more rapidly and more completely than other common disinfecting agents; it is the most active, readily available oxidizing agent; and it has the ability to react swiftly and effectively on many strains of viruses.
Ozone can be produced from oxygen in the air or from pure oxygen. For the continuous production of ozone, feed gas is circulated between two electrodes separated by a narrow gap. The application of a high voltage alternating current creates an electric field throughout the gap which acts on the oxygen to form ozone. Before the gas enters the ozonator it must be dried. This is done by using a refrigeration unit followed by a desiccant dryer. Exit dewpoints out of this system are usually around -76°F.
It is the primary reason to dry compressed air is to prevent either condensation or freezing of water vapor at lower temperatures. This category includes the drying of compressed air for instrumentation. In situations of extreme ambient temperatures, the formation of water or ice in the air lines can cause malfunctioning or stoppage of control instruments. While the broad category of “instrument air” is covered in this type of application, a similar circumstance could be encountered for plant air used for air tools, or operation of other pneumatic devices; compressed air for circuit breaker applications, and other cases where freeze-ups and air stoppage of compressed air is undesirable.
In the metals industry, a blanketing or protective gas is used in many heat treatment processes. The gas is dried to produce a more uniform metal.
Steel is sometimes annealed in a controlled atmosphere prepared by the partial combustion of natural gas. An exothermic base gas is an inert gas generated when natural gas is burned with a controlled amount of air which produces mostly nitrogen with 0.2% – 0.5% combustibles and 0% – 0.2% maximum oxygen. During the combustion, a considerable amount of water vapor is formed. The gas is cooled and then dried by a desiccant dryer. The gas then blankets the steel during heat treating to prevent oxidation.
In aluminum heat treating or annealing, an exothermic gas is used. Too much moisture in the furnace atmosphere can cause oxidation of the alloying constituents. The amount of moisture is extremely critical whenever a metal is exposed to processing. This includes not only heat treating but polishing; carburizing; and welding of titanium, stainless, and other alloys.
A hydrogen atmosphere is used in copper-brazing furnaces for annealing highly oxidizable metals. Where even a slight amount of moisture is extremely detrimental, nickel, nickel steel, and monel wires must be annealed in these furnaces to avoid discoloration.
Another heat treating atmosphere used to a large extent is cracked ammonia. Anhydrous ammonia is dissociated into a gas resulting in three parts of hydrogen to one part of nitrogen. Most cracking units are highly efficient so that the degree of dissociation is usually 99.75% or 99.95%. Since one volume of ammonia yields two volumes of the mixed gas, the ammonia content is 0.125 to 0.025 percent by volume respectively, or 2500 and 500 PPM weight. A molecular sieve dryer is used to remove water and the ammonia.
A gas of increasing importance in the heat treating of metals is HNX gas. This gas has excellent properties in the bright annealing process and is nearly neutral with regard to carburization when treating steels with different carbon contents. Thus, the gas can be used universally. This makes the gas distribution within the workshop easier and enables the purchase of larger and more economical gas production plants.
HNX gas is produced by the controlled combustion of fuel gas. This gas must be dried before being used in a furnace.
Some natural gas wells furnish gas of very high purity, that is, almost pure methane. However, most hydrocarbon streams are complex mixtures of hundreds of different compounds. A typical wellstream is a high velocity, turbulent, constantly expanding mixture of gases and hydrocarbons intimately mixed with water vapor, free water, solids, and other contaminants.
Contaminant removal processes can be divided into two groups: dehydration and purification. The principle reasons for the importance of natural gas dehydration include the following:
1. Liquid water and natural gas can form solid ice-like hydrates which can plug valves, piping, etc.
2. Natural gas containing liquid water is corrosive, particularly if it contains CO2 or H2S.
3. Water vapor in natural gas pipelines may condense, causing sluggish flow conditions.
4. Water vapor increases the volume and decreases the heating value of natural gas thus leading to reduced line capacity.
5. Dehydration of natural gas prior to cryogenic processing is a must to prevent ice formation on low temperature heat exchangers.
Of these, the most common reason for dehydration is the prevention of hydrate formation in gas pipelines. Natural gas hydrates are solid crystalline compounds formed by the chemical combination of natural gas and water under pressure at temperatures considerably above the freezing point of water. In the presence of free water, hydrates will form when the temperature is below a certain point called the hydrate temperature.
Hydrate formation is often confused with condensation and the distinction between the two must be clearly understood.
Condensation of water from natural gas under pressure occurs when the temperature is at or below the dewpoint at that pressure. Free water obtained under such conditions is essential to formation of hydrates which will occur at or below the hydrate temperature at the same pressure.
During the flow of natural gas, it is necessary to avoid conditions that promote the formation of hydrates. This is essential since hydrates may choke the flow stream, surface lines, and other equipment. Hydrate formation in the flow stream results in a lower value for measured wellhead pressures. In a flowrate measuring device, hydrate formation results in lower apparent flow rate. Excessive hydrate formation may also completely block flowlines and service equipment.
Thus, the need for prevention of hydrate formation is obvious, and the easiest way to eliminate hydrates is to substantially remove the water from the natural gas stream. The most efficient method for removing the water present in a natural gas stream is by adsorption with a solid desiccant such as molecular sieve or activated alumina.
Another important application for desiccant drying is the liquefaction of natural gas. Methane is converted into a liquid in a cryogenic process at -285°F (-176°C) and atmospheric pressure. There is a 600 to 1 reduction in volume. As a liquid, large volumes of methane can be easily transported and/or stored. Natural gas companies liquefy and store gas (1 to 20 MMSCFD) during low demand periods and use the stored liquid during high periods of demand. Natural gas found in remote areas can be liquefied and transported to places of demand. Because of the low dewpoints needed for the cryogenic production of LNG, dryers are used.
Custom Dryers Filtration
The type SF and type F filters provide high efficiency filtration. The type SF is a coalescing pre-filter. The type F is our particulate after-filter.
This market covers mostly the drying and purification of gases such as air, oxygen, nitrogen, carbon dioxide, helium, hydrogen, etc. by manufacturers of these gases.
For example, air is compressed and sent through a series of heat exchangers to very low temperatures so that nitrogen and oxygen are separated and liquefied. Before going through these exchangers, the water and CO2 must be removed by an adsorption system or freeze-up will occur. Over 550 billion cubic feet of nitrogen and 350 billion cubic feet of oxygen were produced by this method in 1985. The major end uses for these gases are blanketing atmospheres for the chemical industry, electronics, manufacturing, enhanced oil recovery, metals treating and processing, and metals manufacturing and fabricating.
Carbon dioxide is another gas that is dried by solid adsorption. Over 4 million tons a year of CO2 are produced. It is recovered from synthesis gas in ammonia production, from refinery production of hydrogen, from fermentation processes and from natural wells. The main uses of carbon dioxide are refrigeration, beverage carbonation, urea manufacture, and enhanced oil recovery. Carbon dioxide is dried for production purposes. The presence of moisture in carbon dioxide can also cause process line freeze-up at high pressures along with corrosion problems.
Both helium and hydrogen are also dried and purified before liquefaction. Both are used for rocket propulsion.
This market includes the drying of solvents used for cleaning and/or purification of a material. This type of drying is found in chemical plants, refineries, manufacturing plants, etc. where a material is rinsed by a hydrocarbon stream, then recycled, dried, and returned to cleanse the material. For example, an acetone liquid stream is used to wash a thread used for making tea bags. The dirty acetone leaves the washing tank and enters a carbon purification system. It then enters a distillation column. The column vaporizes the acetone, leaving most of the contaminants. Out of this system, the acetone contains about 2% water. The acetone is dried in a Lectrodryer adsorption system and returned to the washing tank.
REPRESENTATIVE TYPES OF SOLVENTS BEING RECOVERED
A PARTIAL LIST OF INDUSTRIES UTILIZING SOLVENTS
This application covers the drying of air or gas for material handling, dry rooms, and general space dehumidification. We are all familiar with the clogging of salt shakers on the humid days of summer. Similarly, powered industrial materials can be hygroscopic in nature and adsorb water vapor from the atmosphere causing them to lump and clog handling equipment.
Lectrodryers have been used for removing atmospheric moisture from the air in contact with these hygroscopic materials, keeping them free-flowing in conveying systems, hoppers, bins, etc.
In the field of space dehumidification, many materials are package, tableted, and processed in low relative humidities to duplicate wintertime humidities at all times during the year.
The Lectrobreather tank vent dryer prevents atmospheric moisture from entering storage tanks during the “breathing” process, protecting valuable oils and chemical solutions from water contamination.
A common application for the Lectrobreather is in sulfuric acid tanks. In applications such as sulfuric acid where chemicals emit corrosive fumes, a stainless steel vent valve assembly is used to prevent fumes from entering the Lectrobreather.
A reactivator is also available to recharge the desiccant once it becomes saturated with moisture. The need for reactivation is indicated when the desiccant in the moisture indicator window is pink.
Applications for drying and purification for manufacturing or processing of chemical products are numerous. There are no specific applications that are used more than others. Lectrodryers have been used to dry and purify feed stocks of all types of chemicals. The following are just a few applications Lectrodryer has systems for:
XYLENE for the manufacturing of polyester fibers, blow-molded items (mostly bottles) and films
BENZENE for the manufacturing of styrenic plastics, resins, and nylons
BUTADIENE for the manufacturing of fabricated rubber products and fiber
PROPYLENE for the manufacturing of fabricated plastics and fiber
ETHYLENE for the manufacturing of fabricated plastics, antifreeze, and fibers
ACETONE for producing pharmaceutical products
ETHANOL/METHANOL for producing artificial sweetener
REFRIGERANTS for sale in refrigeration units
ACETYLENE for producing vinyl chloride monomer (PVC) pipe
TOLUENE for producing pharmaceutical products
METHYLENE CHLORIDE for producing pharmaceutical products
TETRAHYDRAFURAN for producing pharmaceutical products
HYDROGEN for use in chemical plant processes
AMMONIA SYNTHESIS GAS formanufacturing of fertilizers
SYNTHESIS GAS formanufacturing of intermediate chemicals
Hydrogen is used to cool large stationary generators because of hydrogen’s high heat capacity and low viscosity. The hydrogen must be kept dry in order to maintain these properties. Ambient moisture is considered a contaminant which will reduce the heat capacity and increase the viscosity of the cooling hydrogen. In this application, the dryness of the hydrogen is maintained by a Lectrodryer.
Whether it’s for pressurized horn reflectors and wave guide systems, for telephone control rooms or video signal generation, in fact, wherever a controlled atmosphere is needed you can rely on Lectrodryer twin tower systems to provide a continuous source of dry air and automatically maintain system pressure within a present range.
Even though there are new petroleum refinery processes being used everyday and new applications for adsorption systems in this market, the majority will be in the following:
CATALYTIC REFORMING – Catalytic reforming refers to the octane improvement of straight run gasoline and cracked refinery naphthas. C5 and C6 naphthenes are isomerized and dehydrogenated to aromatics; paraffins are hydrocracked or cyclized and hydrogenated to aromatics.
The reactions are carried out in a series of three or four fixed bed reactors; and, since the reactions are endothermic, heating furnaces are placed at the inlet to each reactor. Hydrogen is recycled to prevent carbon lay down.
Catalytic reforming is also a source of benzene, toluene, and xylene. The feed for this production is naphtha.
All catalytic reforming reactions produce large quantities of hydrogen. Since many of these reformers are regenerated, an inert and recycled gas is used. Applications for an adsorption system then are: (1) dry and purify recycled hydrogen, (2) dry and desulfurize naphtha feed stock, (3) dry regeneration gas from inert gas generation, (4) dry recycled regeneration gas, and (5) purify the hydrogen produced during reforming for sale and other refinery use.
ALKYLATION – Alkylation is the union of an olefinic with a paraffinic hydrocarbon to obtain high octane gasoline. Alkylation is favored over polymerization since only one mole of olefin is reacted per mole of alkylate produced, thus conserving valuable olefinic stock.
The reaction is catalyzed by hydrofluoric or sulfuric acid. In most processes, the reactive olefin is injected into the stable paraffinic feed stock and the combined streams contacted with the acid. The paraffin concentration is kept in large excess to prevent copolymerization of the olefin. This acid alkylation, however, is limited to isobutane with propylene, butylene, and pentylene. Other alkylations: phosphoric acid is used as a catalyst to unite propylene and benzene to form isopropyl benzene; alumina chloride and HCl catalyzes ethylene and benzene to ethylbenzene. An application for an adsorption system would be to dry and purify these streams to rid them of water, mercaptans, and other impurities in the olefin and paraffin feeds that will increase acid consumption and decrease product quality.
ISOMERIZATION – Isomerization is the conversion of normal butane, pentane, and hexane into their respective iso-isomers. It is a fixed bed, vapor phase process which is carried out under a dry hydrogen atmosphere. The catalyst is usually AlCl3 or HCl loaded on silica-alumina.
The reaction is carried out in this hydrogen atmosphere to prevent coke deposition and saturate any cracking products. Applications for adsorption systems then are: (1) dry and purify the paraffin feed, and (2) dry and purify the hydrogen feed.
CATALYTIC CRACKING – Catalytic cracking consists of breaking saturated C12+ molecules into C1-C4 olefins and paraffins, gasoline, light oil, and coke. The majority of the reactions are endothermic, and heat must be supplied to induce a reaction. Cracking can be either thermal or catalytic. There are two types of catalytic cracking systems, the moving bed system and the fluidized system. An application for an adsorption system would be purification of the light ends (C4 and lighter paraffins and olefins) which are sent to the gas recovery plants for later use in alkylation units.
HYDROCRACKING – Hydrocracking can supply the refinery with the entire range of petroleum fuels from propane to desulfurized residual oil with feed stocks ranging from very heavy sulfur laden distillate to light gas oils. The reactions are similar to catalytic cracking reactions, but with hydrogenation superimposed. Polyaromatics are hydrogenated, naphthene rings are opened, olefins are hydrogenated, paraffins are cracked and isomerized. The reaction occurs in a hydrogen atmosphere in the presence of a catalyst. Most hydrocracking units are fixed bed reactors that are regenerated. Regeneration gas is used to reactivate the catalyst. Applications for adsorption systems include: (1) dry the makeup hydrogen, (2) dry and purify the recycle hydrogen, (3) dry and purify the regeneration gas, and (4) purify the hydrocracking products.
GAS PLANT -The C4 and lighter gases from various refinery operations are sent to this section of the refinery. All of these gases require dehydration.
This market covers mostly the drying and purification of gases such as air, oxygen, nitrogen, carbon dioxide, helium, hydrogen, etc. by manufacturers of these gases.
For example, air is compressed and sent through a series of heat exchangers to very low temperatures so that nitrogen and oxygen are separated and liquefied. Before going through these exchangers, the water and CO2 must be removed by an adsorption system or freeze-up will occur. Over 550 billion cubic feet of nitrogen and 350 billion cubic feet of oxygen were produced by this method in 1985. The major end uses for these gases are blanketing atmospheres for the chemical industry, electronics, manufacturing, enhanced oil recovery, metals treating and processing, and metals manufacturing and fabricating.
Carbon dioxide is another gas that is dried by solid adsorption. Over 4 million tons a year of CO2 are produced. It is recovered from synthesis gas in ammonia production, from refinery production of hydrogen, from fermentation processes and from natural wells. The main uses of carbon dioxide are refrigeration, beverage carbonation, urea manufacture, and enhanced oil recovery. Carbon dioxide is dried for production purposes. The presence of moisture in carbon dioxide can also cause process line freeze-up at high pressures along with corrosion problems.
Both helium and hydrogen are also dried and purified before liquefaction.
Nuclear plants require systems that are designed to comply with their strict regulations. Lectrodryer has solutions to reduce radioactive exposure for operators by improving processes like purging the hydrogen cooled generator faster, ensuring that hydrogen purity is maintained at appropriate levels and that gassing and degassing operations can be automated and performed remotely if necessary.
Our current offerings include:
If you are interested in developing a new system or upgrading your existing auxiliaries, we offer engineering and manufacturing services.
For additional information on the products click here or contact us at info@lectrodryer.com
In 1935, Lectrodryer designed the first hydrogen dryer to maintain appropriate dewpoint for the hydrogen used in the first hydrogen cooled generators. Since then, we have not only set the technology standard for that application but expanded to other auxiliaries within the power plant as well. Our current offerings include:
If you are interested in developing a new system or upgrading your existing auxiliaries, we offer engineering and manufacturing services.
For additional information on the products click here or contact us at info@lectrodryer.com
Some natural gas wells furnish gas of very high purity, that is, almost pure methane. However, most hydrocarbon streams are complex mixtures of hundreds of different compounds. A typical wellstream is a high velocity, turbulent, constantly expanding mixture of gases and hydrocarbons intimately mixed with water vapor, free water, solids, and other contaminants.
Contaminant removal processes can be divided into two groups: dehydration and purification. The principle reasons for the importance of natural gas dehydration include the following:
1. Liquid water and natural gas can form solid ice-like hydrates which can plug valves, piping, etc.
2. Natural gas containing liquid water is corrosive, particularly if it contains CO2 or H2S.
3. Water vapor in natural gas pipelines may condense, causing sluggish flow conditions.
4. Water vapor increases the volume and decreases the heating value of natural gas thus leading to reduced line capacity.
5. Dehydration of natural gas prior to cryogenic processing is a must to prevent ice formation on low temperature heat exchangers.
Of these, the most common reason for dehydration is the prevention of hydrate formation in gas pipelines. Natural gas hydrates are solid crystalline compounds formed by the chemical combination of natural gas and water under pressure at temperatures considerably above the freezing point of water. In the presence of free water, hydrates will form when the temperature is below a certain point called the hydrate temperature.
Hydrate formation is often confused with condensation and the distinction between the two must be clearly understood.
Condensation of water from natural gas under pressure occurs when the temperature is at or below the dewpoint at that pressure. Free water obtained under such conditions is essential to formation of hydrates which will occur at or below the hydrate temperature at the same pressure.
During the flow of natural gas, it is necessary to avoid conditions that promote the formation of hydrates. This is essential since hydrates may choke the flow stream, surface lines, and other equipment. Hydrate formation in the flow stream results in a lower value for measured wellhead pressures. In a flowrate measuring device, hydrate formation results in lower apparent flow rate. Excessive hydrate formation may also completely block flowlines and service equipment.
Thus, the need for prevention of hydrate formation is obvious, and the easiest way to eliminate hydrates is to substantially remove the water from the natural gas stream. The most efficient method for removing the water present in a natural gas stream is by adsorption with a solid desiccant such as molecular sieve or activated alumina.
Another important application for desiccant drying is the liquefaction of natural gas. Methane is converted into a liquid in a cryogenic process at -285°F (-176°C) and atmospheric pressure. There is a 600 to 1 reduction in volume. As a liquid, large volumes of methane can be easily transported and/or stored. Natural gas companies liquefy and store gas (1 to 20 MMSCFD) during low demand periods and use the stored liquid during high periods of demand. Natural gas found in remote areas can be liquefied and transported to places of demand. Because of the low dewpoints needed for the cryogenic production of LNG, dryers are used.
Lectrodryer has developed a line of regenerative dryers for natural gas refueling stations. The dryers are designed to dry pipeline gas to J1616 standards or as required by the area served by the station. Lectrodryer CNG dryers are currently in service at a number of transit systems, U.S. Government locations, and retail outlets.
Even though there are new petroleum refinery processes being used everyday and new applications for adsorption systems in this market, the majority will be in the following:
CATALYTIC REFORMING – Catalytic reforming refers to the octane improvement of straight run gasoline and cracked refinery naphthas. C5 and C6 naphthenes are isomerized and dehydrogenated to aromatics; paraffins are hydrocracked or cyclized and hydrogenated to aromatics.
The reactions are carried out in a series of three or four fixed bed reactors; and, since the reactions are endothermic, heating furnaces are placed at the inlet to each reactor. Hydrogen is recycled to prevent carbon lay down.
Catalytic reforming is also a source of benzene, toluene, and xylene. The feed for this production is naphtha.
All catalytic reforming reactions produce large quantities of hydrogen. Since many of these reformers are regenerated, an inert and recycled gas is used. Applications for an adsorption system then are: (1) dry and purify recycled hydrogen, (2) dry and desulfurize naphtha feed stock, (3) dry regeneration gas from inert gas generation, (4) dry recycled regeneration gas, and (5) purify the hydrogen produced during reforming for sale and other refinery use.
ALKYLATION – Alkylation is the union of an olefinic with a paraffinic hydrocarbon to obtain high octane gasoline. Alkylation is favored over polymerization since only one mole of olefin is reacted per mole of alkylate produced, thus conserving valuable olefinic stock.
The reaction is catalyzed by hydrofluoric or sulfuric acid. In most processes, the reactive olefin is injected into the stable paraffinic feed stock and the combined streams contacted with the acid. The paraffin concentration is kept in large excess to prevent copolymerization of the olefin. This acid alkylation, however, is limited to isobutane with propylene, butylene, and pentylene. Other alkylations: phosphoric acid is used as a catalyst to unite propylene and benzene to form isopropyl benzene; alumina chloride and HCl catalyzes ethylene and benzene to ethylbenzene. An application for an adsorption system would be to dry and purify these streams to rid them of water, mercaptans, and other impurities in the olefin and paraffin feeds that will increase acid consumption and decrease product quality.
ISOMERIZATION – Isomerization is the conversion of normal butane, pentane, and hexane into their respective iso-isomers. It is a fixed bed, vapor phase process which is carried out under a dry hydrogen atmosphere. The catalyst is usually AlCl3 or HCl loaded on silica-alumina.
The reaction is carried out in this hydrogen atmosphere to prevent coke deposition and saturate any cracking products. Applications for adsorption systems then are: (1) dry and purify the paraffin feed, and (2) dry and purify the hydrogen feed.
CATALYTIC CRACKING – Catalytic cracking consists of breaking saturated C12+ molecules into C1-C4 olefins and paraffins, gasoline, light oil, and coke. The majority of the reactions are endothermic, and heat must be supplied to induce a reaction. Cracking can be either thermal or catalytic. There are two types of catalytic cracking systems, the moving bed system and the fluidized system. An application for an adsorption system would be purification of the light ends (C4 and lighter paraffins and olefins) which are sent to the gas recovery plants for later use in alkylation units.
HYDROCRACKING – Hydrocracking can supply the refinery with the entire range of petroleum fuels from propane to desulfurized residual oil with feed stocks ranging from very heavy sulfur laden distillate to light gas oils. The reactions are similar to catalytic cracking reactions, but with hydrogenation superimposed. Polyaromatics are hydrogenated, naphthene rings are opened, olefins are hydrogenated, paraffins are cracked and isomerized. The reaction occurs in a hydrogen atmosphere in the presence of a catalyst. Most hydrocracking units are fixed bed reactors that are regenerated. Regeneration gas is used to reactivate the catalyst. Applications for adsorption systems include: (1) dry the makeup hydrogen, (2) dry and purify the recycle hydrogen, (3) dry and purify the regeneration gas, and (4) purify the hydrocracking products.
GAS PLANT -The C4 and lighter gases from various refinery operations are sent to this section of the refinery. All of these gases require dehydration.
This market covers the drying of air or oxygen to make ozone in sewage treatment plants. Ozone, a strong smelling gas, exists in greatest quantities in the upper layers of the earth’s atmosphere. To exist, it requires a substantial amount of energy, which it gets from the sun.
At normal temperatures and pressure found on the earth’s surface, ozone (O3) is unstable. It decomposes into molecular oxygen (O2) and atomic oxygen (O). Since ozone and atomic oxygen have considerable oxidizing power, this gas becomes a prime choice for eliminating color, taste, odor, bacteria, and viruses from water.
In addition, ozone has numerous advantages over other disinfectants: it leaves no traces; its reactions do not produce toxic halogenated compounds; it acts more rapidly and more completely than other common disinfecting agents; it is the most active, readily available oxidizing agent; and it has the ability to react swiftly and effectively on many strains of viruses.
Ozone can be produced from oxygen in the air or from pure oxygen. For the continuous production of ozone, feed gas is circulated between two electrodes separated by a narrow gap. The application of a high voltage alternating current creates an electric field throughout the gap which acts on the oxygen to form ozone. Before the gas enters the ozonator it must be dried. This is done by using a refrigeration unit followed by a desiccant dryer. Exit dewpoints out of this system are usually around -76°F.
Digester gas or land fill gas is recovered and utilized to fuel the motors of generators which produce electric power. Moisture in this gas can greatly reduce the life of the generator motors when it forms acids with the impurities typical of this type of gas. Other applications include tank vent breathers for sulfuric acid storage tanks and air dryers used in chlorine padding applications.
This market covers mostly the drying and purification of gases such as air, oxygen, nitrogen, carbon dioxide, helium, hydrogen, etc. by manufacturers of these gases.
For example, air is compressed and sent through a series of heat exchangers to very low temperatures so that nitrogen and oxygen are separated and liquefied. Before going through these exchangers, the water and CO2 must be removed by an adsorption system or freeze-up will occur. Over 550 billion cubic feet of nitrogen and 350 billion cubic feet of oxygen were produced by this method in 1985. The major end uses for these gases are blanketing atmospheres for the chemical industry, electronics, manufacturing, enhanced oil recovery, metals treating and processing, and metals manufacturing and fabricating.
Carbon dioxide is another gas that is dried by solid adsorption. Over 4 million tons a year of CO2 are produced. It is recovered from synthesis gas in ammonia production, from refinery production of hydrogen, from fermentation processes and from natural wells. The main uses of carbon dioxide are refrigeration, beverage carbonation, urea manufacture, and enhanced oil recovery. Carbon dioxide is dried for production purposes. The presence of moisture in carbon dioxide can also cause process line freeze-up at high pressures along with corrosion problems.
Both helium and hydrogen are also dried and purified before liquefaction.
It is The primary reason to dry compressed air is to prevent either condensation or freezing of water vapor at lower temperatures. This category includes the drying of compressed air for instrumentation. In situations of extreme ambient temperatures, the formation of water or ice in the air lines can cause malfunctioning or stoppage of control instruments. While the broad category of “instrument air” is covered in this type of application, a similar circumstance could be encountered for plant air used for air tools, or operation of other pneumatic devices; compressed air for circuit breaker applications, and other cases where freeze-ups and air stoppage of compressed air is undesirable.
In the metals industry, a blanketing or protective gas is used in many heat treatment processes. The drying of this gas is imperative to produce a more uniform metal; a required grade is made with precision and the furnace in which the heat treating is done works with greater regularity.
Steel is sometimes annealed in a controlled atmosphere prepared by the partial combustion of natural gas. An exothermic base gas is an inert gas generated when natural gas is burned with a controlled amount of air which produces mostly nitrogen with 0.2% – 0.5% combustibles and 0% – 0.2% maximum oxygen. During the combustion, a considerable amount of water vapor is formed. The gas is cooled and then dried by a desiccant dryer. The gas then blankets the steel during heat treating to prevent oxidation.
In aluminum heat treating or annealing, an exothermic gas is used. Too much moisture in the furnace atmosphere can cause oxidation of the alloying constituents. The amount of moisture is extremely critical whenever a metal is exposed to processing. This includes not only heat treating but polishing; carburizing; and welding of titanium, stainless, and other alloys.
A hydrogen atmosphere is used in copper-brazing furnaces for annealing highly oxidizable metals. Where even a slight amount of moisture is extremely detrimental, nickel, nickel steel, and monel wires must be annealed in these furnaces to avoid discoloration.
Another heat treating atmosphere used to a large extent is cracked ammonia. Anhydrous ammonia is dissociated into a gas resulting in three parts of hydrogen to one part of nitrogen. Most cracking units are highly efficient so that the degree of dissociation is usually 99.75% or 99.95%. Since one volume of ammonia yields two volumes of the mixed gas, the ammonia content is 0.125 to 0.025 percent by volume respectively, or 2500 and 500 PPM weight. A molecular sieve dryer is used to remove water and the ammonia.
A gas of increasing importance in the heat treating of metals is HNX gas. This gas has excellent properties in the bright annealing process and is nearly neutral with regard to carburization when treating steels with different carbon contents. Thus, the gas can be used universally. This makes the gas distribution within the workshop easier and enables the purchase of larger and more economical gas production plants.
HNX gas is produced by the controlled combustion of fuel gas. This gas must be dried before being used in a furnace.
Custom Dryers Filtration
The type SF and type F filters provide high efficiency filtration. The type SF is a coalescing pre-filter. The type F is our particulate after-filter.
This market includes the drying of solvents used for cleaning and/or purification of a material. This type of drying is found in chemical plants, refineries, manufacturing plants, etc. where a material is rinsed by a hydrocarbon stream, then recycled, dried, and returned to cleanse the material. For example, an acetone liquid stream is used to wash a thread used for making tea bags. The dirty acetone leaves the washing tank and enters a carbon purification system. It then enters a distillation column. The column vaporizes the acetone, leaving most of the contaminants. Out of this system, the acetone contains about 2% water. The acetone is dried in a Lectrodryer adsorption system and returned to the washing tank.
REPRESENTATIVE TYPES OF SOLVENTS BEING RECOVERED
A PARTIAL LIST OF INDUSTRIES UTILIZING SOLVENTS
This market includes the drying of solvents used for cleaning and/or purification of a material. This type of drying is found in chemical plants, refineries, manufacturing plants, etc. where a material is rinsed by a hydrocarbon stream, then recycled, dried, and returned to cleanse the material. For example, an acetone liquid stream is used to wash a thread used for making tea bags. The dirty acetone leaves the washing tank and enters a carbon purification system. It then enters a distillation column. The column vaporizes the acetone, leaving most of the contaminants. Out of this system, the acetone contains about 2% water. The acetone is dried in a Lectrodryer adsorption system and returned to the washing tank.
REPRESENTATIVE TYPES OF SOLVENTS BEING RECOVERED
A PARTIAL LIST OF INDUSTRIES UTILIZING SOLVENTS
This market includes the drying of solvents used for cleaning and/or purification of a material. This type of drying is found in chemical plants, refineries, manufacturing plants, etc. where a material is rinsed by a hydrocarbon stream, then recycled, dried, and returned to cleanse the material. For example, an acetone liquid stream is used to wash a thread used for making tea bags. The dirty acetone leaves the washing tank and enters a carbon purification system. It then enters a distillation column. The column vaporizes the acetone, leaving most of the contaminants. Out of this system, the acetone contains about 2% water. The acetone is dried in a Lectrodryer adsorption system and returned to the washing tank.
REPRESENTATIVE TYPES OF SOLVENTS BEING RECOVERED
A PARTIAL LIST OF INDUSTRIES UTILIZING SOLVENTS
The Lectrobreather tank vent dryer prevents atmospheric moisture from entering storage tanks during the “breathing” process, protecting valuable oils and chemical solutions from water contamination.
A common application for the Lectrobreather is in sulfuric acid tanks. In applications such as sulfuric acid where chemicals emit corrosive fumes, a stainless steel vent valve assembly is used to prevent fumes from entering the Lectrobreather.
A reactivator is also available to allow the desiccant to be reused once it becomes saturated with moisture. Desiccant replacement is also appropriate. Desiccant replacement or reactivation is indicated when the desiccant in the moisture indicator window is pink.
Applications for drying and purification for manufacturing or processing of chemical products are numerous. There are no specific applications that are used more than others. Lectrodryers have been used to dry and purify feed stocks of all types of chemicals. The following are just a few applications Lectrodryer has systems for:
XYLENE for the manufacturing of polyester fibers, blow-molded items (mostly bottles) and films
BENZENE for the manufacturing of styrenic plastics, resins, and nylons
BUTADIENE for the manufacturing of fabricated rubber products and fiber
PROPYLENE for the manufacturing of fabricated plastics and fiber
ETHYLENE for the manufacturing of fabricated plastics, antifreeze, and fibers
ACETONE for producing pharmaceutical products
ETHANOL/METHANOL for producing artificial sweetener
REFRIGERANTS for sale in refrigeration units
ACETYLENE for producing vinyl chloride monomer (PVC) pipe
TOLUENE for producing pharmaceutical products
METHYLENE CHLORIDE for producing pharmaceutical products
TETRAHYDRAFURAN for producing pharmaceutical products
HYDROGEN for use in chemical plant processes
AMMONIA SYNTHESIS GAS formanufacturing of fertilizers
SYNTHESIS GAS formanufacturing of intermediate chemicals
Whether it’s for pressurized horn reflectors and wave guide systems, for telephone control rooms or video signal generation, in fact, wherever a controlled atmosphere is needed you can rely on Lectrodryer twin tower systems to provide a continuous source of dry air and automatically maintain system pressure within a present range.
• Acetylene
• Air (Atmospheric)
• Air (Compressed)
• Air (Instrument)
• Air (Mill)
• Air (Process)
• Air (Utility)
• Acetone
• Acetonitrile
• Acrylonitrile
• Alcohol Dehydration
• Ammonia
• Ammonia Vapor
• Annealing Gas
• Argon
• Atmosphere Gas
• Atmospheric Air
• Benzene
• Butadiene
• Butane
• Butene
• Carbon Dioxide
• Carbon Monoxide
• Carbon Tetrachloride
• Carbonyl Sulfide
• Chlorinated Hydrocarbons
• Chloroform
• Coker Gas
• Controlled Atmosphere Gas
• Crude Argon
• Crude Hydrogen
• Crude SO2
• Cyclohexane
• Cyclohexanone
• Cyclohexylamine
• Deuterium
• Dichlorobenzene
• Dichloropentadiene
• Diesel Fuel
• Diethyl Ether
• Diethylamine
• Dimethyl Formamide
• Dissociated Ammonia
• Ethyl Acetate
• Ethyl Alcohol (Ethanol)
• Ethyl Benzene
• Ethyl Formamide
• Ethylene
• Ethylene Glycol
• Exhaust Gas (Jet)
• Exotherm Gas
• Feed Gas
• Flue Gas
• Freon (Refrigerants)
• Fuel Gas
• Gasoline
• Halon
• Heating Oil
• Helium
• Heptane
• Hexane
• Hydrochloric Acid
• Hydrogen
• Hydrogen Sulfide
• Inert Gas
• Isobutane
• Isobutylene
• Iso-octane
• Jet Fuel
• Kerosene
• Ketones
• Lacquer Thinner
• Light Vacuum Gas Oil
• Methane
• Methyl Bromide
• Methyl Chloride
• Methyl Chloroform
• Methyl Formate
• Methyl Iodide
• Methylal
• Methylene Chloride
• Naphtha (Mineral Spirits)
• Natural Gas
• Nickel Carbonyl
• Nitrogen
• Nitrous Oxide
• Octamethylcyclotetrasiloxane
• (Cylic Siloxane)
• Octane
• Oil Vapor Removal
• Oxygen
• Pentane
• Perchlorethylene
• Phenol
• Propane
• Propylene
• Saturated Hydrocarbons
• Sewage Gas
• Sour Utility Gas
• Styrene
• Sulfur Dioxide
• Sulfur Hexafluoride
• Sulfuric Acid
• Syntheses Gas
• T-H Dimer
• Tank Vent Dryer
• Tetrahydrofuran (THF)
• Toluene
• Unsaturated Hydrocarbons
• Vinyl Acetate
• Vinyl Chloride
• Waste Treatment Air
• Xylene
Requesting a quote from Lectrodryer is easy – simply fill out the RFQ form to the right. However, to help us give you the most accurate quote, please provide as much information as possible including:
• Fluid to be Dried
• Operating Conditions (Minimum and Maximum Temperature and Pressure)
• Entering Moisture/ Contaminants content
• Utilities Available
• Equipment Specifications
• Design Pressure
• Flow
• Optional Features Desired
In general, the more information you put in the RFQ Message section, the better we can address your inquiry.
You can also download our Application Questionnaire and email it to info@lectrodryer.com
Requesting a quote from Lectrodryer is easy – simply fill out the RFQ. However, to help us give you the most accurate quote, please provide as much information as possible.
