EP0021748B1 - A process for the production of an acetylene base stable fuel gas, the products obtained by this process and the use of the produced acetylene base fuel gas - Google Patents

A process for the production of an acetylene base stable fuel gas, the products obtained by this process and the use of the produced acetylene base fuel gas Download PDF

Info

Publication number
EP0021748B1
EP0021748B1 EP80301997A EP80301997A EP0021748B1 EP 0021748 B1 EP0021748 B1 EP 0021748B1 EP 80301997 A EP80301997 A EP 80301997A EP 80301997 A EP80301997 A EP 80301997A EP 0021748 B1 EP0021748 B1 EP 0021748B1
Authority
EP
European Patent Office
Prior art keywords
process according
carbide
acid
reagent
water
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
EP80301997A
Other languages
German (de)
English (en)
French (fr)
Other versions
EP0021748A1 (en
Inventor
Edward O. Hayes
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
National Research Development Inc
Original Assignee
National Research Development Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by National Research Development Inc filed Critical National Research Development Inc
Priority to AT80301997T priority Critical patent/ATE9711T1/de
Publication of EP0021748A1 publication Critical patent/EP0021748A1/en
Application granted granted Critical
Publication of EP0021748B1 publication Critical patent/EP0021748B1/en
Expired legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10H—PRODUCTION OF ACETYLENE BY WET METHODS
    • C10H21/00—Details of acetylene generators; Accessory equipment for, or features of, the wet production of acetylene
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10H—PRODUCTION OF ACETYLENE BY WET METHODS
    • C10H15/00—Acetylene gas generators with carbide feed, with or without regulation by the gas pressure

Definitions

  • This invention relates to an improved, economical, efficient process for generating an acetylene base fuel gas of enhanced stability and safety and of high BTU content that will burn, for example, to heat boilers or power internal combustion engines, with a minimum amount of deleterious emissions.
  • the invention also relates to a process for producing an acetylene base fuel gas with no undesirable byproducts, such as calcium hydroxide, which create disposal problems. Instead, the by-product of this process is an excellent top cylinder lubricant (TCL) when the gas is used as a fuel for internal combustion engines.
  • TCL top cylinder lubricant
  • the acetylene produced by both processes is thermodynamically unstable even at room temperatures and even in the absence of air, as is well known in the art.
  • the thermal decomposition of acetylene can proceed so rapidly that explosions and detonations may result. Consequently, governmental safety regulations prescribe detailed procedures for handling, storage, and shipment of acetylene.
  • the above- mentioned Osborg patent also suggests the addition of an inert "carrier” liquid, e.g., an alcohol, an amine, or a glycol, to the water to have better control and reduce the exothermic heat of the reaction.
  • an inert "carrier” liquid e.g., an alcohol, an amine, or a glycol
  • a glycol to the water for anti-freeze purposes also is suggested in "Acetylene, Its Properties, Manufacture and Uses" by Miller, Vol. I, 1965, Academic Press, pages 291-292. Unfortunately, each of the processes of Mackusick, Osborg and the publication "Acetylene, etc.” remain plagued by the formation of unwanted lime as a by-product.
  • creosote If the creosote is undiluted, however, it must be neutralized with potassium hydrate or other suitable alkali before the carbide is used to produce acetylene by contact with water. If the creosote is diluted, the protection from air or water is weakened greatly, although the carbide may be used without neutralization but with the acetylene-generating reaction with water slowed considerably. These prior processes for avoiding premature hydrolysis of carbide suffer from the problem that pretreatment of the carbide prior to generation of acetylene is required or else the generation is slowed to an impractical rate.
  • a further object of the present invention is to provide a novel top cylinder lubricant composition which forms a part of an acetylene base fuel gas for an internal combustion engine.
  • an improved process for producing an acetylene base relatively safe fuel gas of enhanced stability which comprises reacting a metal carbide (preferably an alkaline earth metal carbide) with an aqueous liquid activator reagent comprising water, an alkylene glycol or an alcohol or a mixture thereof as a water-soluble reaction-rate-controlling substance and a strong inorganic acid, such as hydrochloric, sulfuric, phosphoric, carbonic or nitric acid or a mixture thereof.
  • a metal carbide preferably an alkaline earth metal carbide
  • an aqueous liquid activator reagent comprising water, an alkylene glycol or an alcohol or a mixture thereof as a water-soluble reaction-rate-controlling substance and a strong inorganic acid, such as hydrochloric, sulfuric, phosphoric, carbonic or nitric acid or a mixture thereof.
  • calcium carbide is reacted with a liquid aqueous activator reagent which comprises water, a lower alkylene glycol (preferably ethylene glycol) and a strong inorganic acid (preferably hydrochloric acid).
  • a liquid aqueous activator reagent which comprises water, a lower alkylene glycol (preferably ethylene glycol) and a strong inorganic acid (preferably hydrochloric acid).
  • the invention further provides a means for stabilizing calcium carbide so as to render it impermeable to air and moisture by coating particles of calcium carbide with an air and moisture impermeable film, preferably of nitrocellulose and a polyester resin, which is attacked and dissolved when brought into contact with the aqueous liquid activator reagent of the present invention.
  • the acetylene base fuel produced according to the present invention is a gaseous reaction product which further includes vaporized or entrained by-product compounds which are a most effective top cylinder lubricant for an internal combustion engine.
  • the acetylene base fuel gas produced according to the present invention exhibits enhanced BTU output over that of natural gas, i.e., up to about 1447 per cubic foot (54.5 x 1 06 J/m 3 ) for the gas of the present invention as contrasted to about 1448 BTU 54.6x 10 6 J/m 3 ) for pure acetylene and about 879 BTU 33.1 x 1 0 6 J/m 3 ) for natural gas.
  • a significant advantage which resides in the process herein disclosed is the elimination of lime waste disposal problems attendant on the conventional reaction of calcium carbide with water. Utilizing the aqueous liquid activator the formation of lime waste by-product is eliminated and provides for a reagent medium which can be used for extended periods of time without replenishment.
  • the acetylene base fuel gas which is produced in accordance with the present invention is characterized by having enhanced storage capabilities.
  • acetylene produced according to conventional methods from carbide needs be made in reactor and stored in the presence of a flammable solvent filler, such as acetone, at a pressure not exceeding 15 psi (1.03 bar).
  • the acetylene base fuel gas obtained according to the present invention may be stored at relatively high pressures (e.g., up to 250 psi-1 7.24 bar) without the presence of a solvent filler such as acetone, thereby permitting high storage capabilities. Storage in the presence of the activator actually enhances the ability of the gas to be stored at high pressures.
  • the acetylene base fuel gas obtained in accordance with the present invention is relatively stable and will not decompose readily at room temperatures, even in the presence of air.
  • a further advantage of the process of this invention is that the reaction is far less exothermic than that of calcium carbide with water alone. In fact, the amount of heat generated in the reaction is so low as to require no cooling of the generator.
  • the reaction of calcium carbide in water results in a heat of reaction of 215°F (101°C) whereas the heat of reaction utilizing the reagent of the present invention is 140°F (60°C).
  • the present invention provides a process for producing an acetylene base fuel gas which comprises the steps of reacting a metal carbide, preferably an alkaline earth metal carbide, with an aqueous liquid activator reagent composed of water, an alkylene glycol or an alcohol or a mixture thereof as a water-soluble reaction-rate-controlling substance (preferably a water-soluble lower alkylene glycol), and an inorganic strong acid.
  • a metal carbide preferably an alkaline earth metal carbide
  • an aqueous liquid activator reagent composed of water, an alkylene glycol or an alcohol or a mixture thereof as a water-soluble reaction-rate-controlling substance (preferably a water-soluble lower alkylene glycol), and an inorganic strong acid.
  • the preferred carbide is calcium carbide. It will be appreciated by those skilled in the art, however, that other carbides can be employed, such as aluminum carbide and iron carbide, at a resulting increase in cost.
  • Suitable inorganic strong acids include hydrochloric, sulfuric phosphoric, carbonic and nitric acids, or mixtures thereof, with hydrochloric acid being preferred for ready availability, low cost and lack of unpleasant side reactions.
  • reaction-rate-controlling substance not only retards the rate of reaction but also contributes to the stability of the gas produced. In addition the substance serves to lower the reaction temperature.
  • Suitable reaction-rate-controlling substances are water-soluble alkylene glycols and water-soluble alcohols, or mixtures thereof, with the glycols being preferred because of their uninflammability.
  • the liquid activator reagent is prepared by mixing the water and substance components and then introducing the acid, such as hydrochloric acid, into the water-substance mixture.
  • the carbide then is added, at a controlled rate, to the reagent, rather than vice-versa, for better control of the release of gas.
  • the reaction of the liquid activator reagent with calcium carbide can be carried out at atmospheric pressure or at moderate pressures, say of the order of 18 psi (1.24 bar), and produces a fuel gas containing upwards of 89%, or even more, acetylene, which fuel gas also contains vaporized and/or entrained compounds which form a most effective top cylinder lubricant for an internal combustion engine.
  • a decrease in the proportion of the glycol in the reagent increases the reaction rate and vice-versa.
  • an increase in the proportion of the acid increases the reaction rate and vice-versa.
  • the reaction proceeds uniformly and relatively slowly without foaming (which occurs in the conventional "wet" method of producing acetylene and which inhibits release of the gas) and without the formation of a by-product hydroxide precipitate. If the glycol proportion is decreased below the minimum level, the gas tends to become unstable and hazardous like acetylene generated by the reaction of calcium carbide with water only.
  • the glycol proportion should be large enough to insure stability of the gas with the attendant advantage of being subjectable to higher pressures without danger, and so that the reaction can be better controlled, i.e. uniformly regulated. Further, a decrease in the glycol proportion results in a decrease in the TCL by-product, so it would seem that the glycol enters into the reaction. If the acid proportion is decreased below the minimum level, an undesirable hydroxide by-product precipitate is formed which presents a disposal problem.
  • the gas is produced at a uniform rate leaving a greasy oily by-product residue, having some particulate matter, floating on the liquid reagent.
  • This residue can be removed easily by circulating the reagent through an appropriate filtering system.
  • the by-product residue forms an excellent lubricant for moving parts.
  • the reagent can be used for long periods of time without replenishment.
  • the main reactant is the carbide.
  • TCL top cylinder lubricant
  • the gaseous fuel of this invention mixes with air more readily than gasoline and when burned produces far less undesirable and deleterious emissions than the burning of gasoline and air.
  • a 1974 Dodge@ van with no catalytic converter was equipped to be selectively powered with gasoline or the gaseous fuel of this invention and the emissions were measured by a State of Arizona vehicle inspection station.
  • the maximum emissions allowed at that inspection were 400 parts per million (PPM) of hydrocarbon (HC) and 5.5% carbon monoxide (CO).
  • PPM parts per million
  • HC hydrocarbon
  • CO carbon monoxide
  • the inspection emission results were 410 HC (PPM) and 14.5% CO and the vehicle failed to pass inspection.
  • the inspection emission results were 60 HC (PPM) and 0.14% CO and the vehicle passed the inspection by a large margin.
  • the process of the present invention employs a special 3-component liquid activator reagent which reacts with the calcium carbide to achieve the results described.
  • the liquid activator reagent comprises water, a water-soluble alkylene glycol or alcohol and a strong inorganic acid, preferably hydrochloric acid.
  • water-soluble alkylene glycol is intended to include all glycols having substantial solubility in water.
  • ethylene glycol is employed in the formation of the liquid activator reagent.
  • water-soluble alcohols is intended to include all alcohols (primary, secondary and tertiary) having substantial solubility in water and generally includes those having from 1 to 8 carbon atoms. Suitable alcohols include methanol, ethanol, isopropanol, butanol and mixtures thereof. Alcohols are not preferred, however, because in general they make the activator reagent flammable.
  • the glycol component is merely mixed with the water component of the activator, for example, in a vessel containing an appropriate agitator, and the acid is then added to the water-glycol mixture.
  • the relative proportions of water, glycol and acid in the liquid activator reagent will have an effect on the rate of the reaction, the final composition of the fuel gas, and the by-product residue or top cylinder lubricant which are produced when the liquid activator reagent is reacted with calcium carbide.
  • the water present in the aqueous liquid activator reagent may be added separately or obtained from the acid employed.
  • the amount of water present must be sufficient to provide the necessary reaction with the carbide material.
  • the presence of the alkylene glycol serves to control the rate of reaction and hence rate of formation of the acetylene base fuel gas, as well as the amount of the TCL by-product, and should be sufficient to provide a smooth even generation of safer more stable gas and an adequate amount of TCL when the gas is used to fuel an internal combustion engine.
  • the presence of the strong inorganic acid should be sufficient to eliminate the formation of a lime (calcium hydroxide) by-product.
  • the liquid reagent of this invention can be prepared and shipped as a two-component concentrate composition, namely, a mixture of a water-soluble alkylene glycol or alcohol and a strong inorganic acid in proper proportions, the mixture to be added to the appropriate amount of water at the reaction site.
  • a suitable concentrate contains from about 35 to 82% by weight of the glycol or alcohol component, e.g., ethylene glycol, and from about 18 to 65% by weight of the acid.
  • Such a concentrate when mixed with water forming about 30 to 60% by weight of the mixture results in the desired activator reagent.
  • the calcium carbide particles in order to enhance the capability of calcium carbide used in the reaction of the present invention to be stored without deterioration, it is preferred to stabilize the calcium carbide particles so as to render the same impermeable to air and moisture. This is accomplished by coating the particles of calcium carbide with a film, impervious to air and moisture but dissoluble by the reagent, preferably composed of nitrocellulose and a polyester resin. In carrying out such a process, one merely contacts the particles of calcium carbide with a slurry of nitrocellulose and polyester resin in a suitable organic solvent such as acetone, isopropyl alcohol or mixtures thereof.
  • a suitable organic solvent such as acetone, isopropyl alcohol or mixtures thereof.
  • the excess slurry is drained and the particles may be dried, for example in a convection dryer, to yield particles having a film thereon impermeable to air and moisture. While the resulting coated particles are impermeable to air and moisture, upon contact with the aqueous liquid activator reagent of the present invention, the coating is broken down or dissolved and reaction occurs to generate the desired acetylene base fuel gas.
  • the fuel gas and associated by-product residue which is an excellent top cylinder lubricant (TCL), are formed by reacting the liquid activator reagent, described above, with granular calcium carbide.
  • the calcium carbide is metered, as required, into a closed reactor or generator containing the liquid activator reagent to produce the requisite quantity of the gaseous acetylene base fuel.
  • the generator desirably is operated at approximately 15-20 psi (1.03-1.26 bar), preferably about 18 psi (1.24 bar).
  • the reaction goes to completion when the quantity of water in the liquid activator reagent in the generator is approximately stoichiometrically equivalent to the calcium carbide metered and charged to the generator, according to the theoretical equation Any calcium hydroxide produced by the reaction is converted to a soluble salt, e.g., CaCl 2 , by reaction with the acid and goes into solution in the reagent.
  • a soluble salt e.g., CaCl 2
  • TCL gaseous acetylene base fuel
  • All that is presently known is that at least a portion of the calcium moiety of the solid calcium carbide fuel appears to react with the glycol and acid components of the liquid activator reagent to form a compound which is at least transiently volatile, or is entrained, and some of which passes from the generator along with the gaseous fuel.
  • the mixture of the compound and gaseous fuel then can be fed into the carburetor of an internal combustion engine or to a fuel burner for a boiler or the like.
  • Experimental observation has determined that the TCL compound is present in a substantially constant amount in the upper portion of the combustion cylinders of an engine when fueled by the gas of this invention.
  • the step of production of the liquid activator reagent consists of two sub-steps involving the mixing of water and the alkylene glycol component.
  • the mixed water-glycol composition is then further mixed by addition of the acid thereto followed by additional mixing.
  • this concentrate is added to the appropriate amount of water at the reaction site.
  • the resulting liquid activator reagent is then charged into a gas production generator into which solid calcium carbide granules are metered.
  • the reaction product from the generator comprising the acetylene base gas-TCL composition mixture is then metered to its point of use, i.e., a burner for a boiler or the like or the carburetion system of an internal combustion engine, where it is burned to provide power.
  • the gaseous product had a molecular weight of 26.3, specific gravity of 0.909 (calculated) and a heating value (BTU-calculated) of 1358 per cubic foot (5 1.2 x 106 J/m 3 ) (dry basis) at 14.696 psia (1 bar) at 60°F (16.5°C).
  • Example one The procedure of Example one was repeated using an activator having the following composition (parts by weight): The resulting gas was collected in a collection tube at 16 psia (1.10 bar) and upon analysis, found to have the following composition:
  • the gaseous product has a specific gravity of 0.894 (calculated) and a heating value (BTU-calculated) of 1424 per cubic foot (53.7x10 6 J/m 3 ) (dry basis) at 14.696 psia (1 bar) at 60°F. (16.5°C).
  • fuel gas was generated by reacting calcium carbide with an activator having the following composition (parts by weight):
  • the resulting gas was collected in a collection tube at 25 psia (1.72 bar) and upon analysis found to have the following composition:
  • the gaseous product has a specific gravity of 0.892 (calculated) and a heating value (BTU-calculated) of 1437 per cubic foot (54.1 X106 J/m 3 ) (dry basis) at 14.696 psia (1 bar) at 60°F. (16.5°C).
  • the gas produced as described can fuel the internal combustion engine of an automobile without detectable atmospheric pollution, with about one-half the amount of acetylene base gas being required to power the engine as compared to natural gas.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Organic Chemistry (AREA)
  • Lubricants (AREA)
EP80301997A 1979-06-18 1980-06-13 A process for the production of an acetylene base stable fuel gas, the products obtained by this process and the use of the produced acetylene base fuel gas Expired EP0021748B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT80301997T ATE9711T1 (de) 1979-06-18 1980-06-13 Verfahren zur herstellung eines stabilen acetylenbrennstoffgases, die nach diesem verfahren erhaltenen produkte und verwendung des hergestellten acetylenbrennstoffgases.

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
US4994879A 1979-06-18 1979-06-18
US49948 1979-06-18
US14530480A 1980-04-30 1980-04-30
US145304 1980-04-30

Publications (2)

Publication Number Publication Date
EP0021748A1 EP0021748A1 (en) 1981-01-07
EP0021748B1 true EP0021748B1 (en) 1984-10-03

Family

ID=26727727

Family Applications (1)

Application Number Title Priority Date Filing Date
EP80301997A Expired EP0021748B1 (en) 1979-06-18 1980-06-13 A process for the production of an acetylene base stable fuel gas, the products obtained by this process and the use of the produced acetylene base fuel gas

Country Status (12)

Country Link
EP (1) EP0021748B1 (xx)
AU (1) AU541763B2 (xx)
BR (1) BR8003766A (xx)
CA (1) CA1179138A (xx)
DE (1) DE3069350D1 (xx)
ES (1) ES493057A0 (xx)
GR (1) GR68769B (xx)
IE (1) IE51141B1 (xx)
IL (1) IL60346A (xx)
MX (1) MX155550A (xx)
PH (1) PH16563A (xx)
PT (1) PT71409A (xx)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
ATE13508T1 (de) * 1981-11-16 1985-06-15 Kemgas International Verfahren zur herstellung eines calciumcarbidproduktes.

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
BE350928A (xx) *
BE498601A (xx) * 1949-10-10 1951-02-01

Also Published As

Publication number Publication date
IL60346A0 (en) 1980-09-16
AU541763B2 (en) 1985-01-17
ES8105772A1 (es) 1981-06-16
DE3069350D1 (en) 1984-11-08
MX155550A (es) 1988-03-25
EP0021748A1 (en) 1981-01-07
GR68769B (xx) 1982-02-17
CA1179138A (en) 1984-12-11
PH16563A (en) 1983-11-18
IE801217L (en) 1980-12-18
IE51141B1 (en) 1986-10-15
PT71409A (en) 1980-07-01
BR8003766A (pt) 1981-01-13
IL60346A (en) 1983-09-30
AU5925580A (en) 1981-01-08
ES493057A0 (es) 1981-06-16

Similar Documents

Publication Publication Date Title
Lopatin Calculation of the process of nitrogen oxides formation during combustion of methanol in the engine
US3664134A (en) Combustion system
CN109956844A (zh) 一种氟聚物/金属复合含能材料的制备方法
WO2010104407A1 (en) Modifier of combustion of solid, liquid and gaseous fuels
CA1135505A (en) Liquid fuel composition, method of preparing said composition and emulsifier
CN1198770A (zh) 乳液燃料及其在燃气轮机中的用途
GB1571210A (en) Cerium compounds method of obtaining said compounds and applications thereof
EP0021748B1 (en) A process for the production of an acetylene base stable fuel gas, the products obtained by this process and the use of the produced acetylene base fuel gas
CN111875458A (zh) 一种多孔粒状铵油炸药用表面活性剂、性能增强剂及炸药
Farzaneh et al. Zn (II) coordination polymer as a bifunctional catalyst for biodiesel production from soybean oil
CN112940807A (zh) 一种节能环保无醇植物油燃料及其制备方法
EP0014228B1 (en) Solid fuel and a process for producing solid fuel
US4080177A (en) Colloidal magnesium suspension in critical low concentration in jet fuel
US1684686A (en) Aqueous liquid fuel
US4110082A (en) Reformed hydrocarbons and alcohols from fuel alloys and reforming agents
US5116390A (en) Catalytically enhanced combustion process
GB2242896A (en) Process for the in-situ production of a sorbent-oxide aerosol used for removing effluents from a gaseous combustion stream
US5516742A (en) Catalytic conversion of water and carbon dioxide to low cost energy, hydrogen, carbon monoxide, oxygen and hydrocarbons
RU2773078C2 (ru) Модификатор твёрдых топлив и способ его применения
CA2013367A1 (en) Fuel additives
RU2196903C2 (ru) Способ форсирования мощности двигателей внутреннего сгорания
CN108485735B (zh) 一种重油、醇基柴油的复合乳化剂
US5710087A (en) Process for catalytic conversion of water and carbon dioxide to low cost energy, hydrogen, carbon monoxide, oxygen and hydrocarbons
CN109609205A (zh) 一种醇基柴油燃料及其制备方法
RU2192543C1 (ru) Горюче-окислительный состав для термохимической обработки призабойной зоны пласта

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Designated state(s): AT BE CH DE FR GB IT LU NL SE

17P Request for examination filed

Effective date: 19810907

ITF It: translation for a ep patent filed
GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Designated state(s): AT BE CH DE FR GB IT LI LU NL SE

REF Corresponds to:

Ref document number: 9711

Country of ref document: AT

Date of ref document: 19841015

Kind code of ref document: T

REF Corresponds to:

Ref document number: 3069350

Country of ref document: DE

Date of ref document: 19841108

ET Fr: translation filed
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
ITTA It: last paid annual fee
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 19930526

Year of fee payment: 14

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: LU

Payment date: 19930602

Year of fee payment: 14

Ref country code: GB

Payment date: 19930602

Year of fee payment: 14

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: AT

Payment date: 19930622

Year of fee payment: 14

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: BE

Payment date: 19930628

Year of fee payment: 14

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: NL

Payment date: 19930630

Year of fee payment: 14

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 19930818

Year of fee payment: 14

EPTA Lu: last paid annual fee
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: CH

Payment date: 19930923

Year of fee payment: 14

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LU

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19940613

Ref country code: GB

Effective date: 19940613

Ref country code: AT

Effective date: 19940613

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: SE

Payment date: 19940622

Year of fee payment: 15

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LI

Effective date: 19940630

Ref country code: CH

Effective date: 19940630

Ref country code: BE

Effective date: 19940630

BERE Be: lapsed

Owner name: NATIONAL RESEARCH AND DEVELOPMENT INC.

Effective date: 19940630

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Effective date: 19950101

EAL Se: european patent in force in sweden

Ref document number: 80301997.5

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 19940613

NLV4 Nl: lapsed or anulled due to non-payment of the annual fee
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Effective date: 19950228

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Effective date: 19950301

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Effective date: 19950614

EUG Se: european patent has lapsed

Ref document number: 80301997.5