Title of Invention	TREATMENT PROCESSES TO REMOVE HYDROGEN SULPHIDE AND MERCAPTAN SULPHUR FROM USED COMPRESSOR OILS FOR SALVAGING AND RECYCLING
Abstract	A process for removal of H2S and Mercaptans sulphur from compressor oil comprising: adding adsorbents under heating in presence of nitrogen bubbling for a certain period of time with stirring; subjecting the oil thus obtained to the step of filtration.

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FIELD OF INVENTION: This invention relates to treatment processes to remove Hydrogen Sulphide and Mercaptan Sulphur from used compressor oils for salvaging and recycling. BACKGROUND OF INVENTION: Heavy water play crucial role in the generation of nuclear energy and is used as moderator and coolant in the reactors using Uranium as fuel. The viability of producing heavy water depends on the isotopic mass transfer rate and chemical exchange process involving hydrogen containing compounds such as H2, H2O, H2S, NH3, CH4 etc.. For acceptable isotopic mass transfer rate the bonds of the above molecules should be made labile. Among available Hydrogen containing molecules the bonds of O-H, S-H and N-H are so much labile that bond braking and making processes occur in isotopic exchange reaction without any catalyst at any temperature. Hence the exchange processes of H2S-H2O and NH3-H2O are preferred, as the reaction does not involve catalyst and can be conducted at any desired temperature. Thus heavy water production utilizes dual temperature exchange process of H2S and water for extracting Deuterium from water up to 15% and subsequent enrichment to reactor grade through vacuum distillation. Thus Hydrogen Sulphide is used in large quantities as carrier gas, which is highly toxic and corrosive in nature. Hydrogen Sulphide gas booster compressors are used in the exchange units to make up the pressure loss for circulating the H2S gas through exchange unit towers. A dedicated seal oil system is provided for supplying seal oil to the compressor seal. The seal oil is likely to get contaminated with H2S over a period of time due to diffusion of gas into the seal oil and hence mixing of seal oil with lube oil result in the contamination of lube oil also. The lube oil is supposed to be free from H2S gas, as any traces of H2S in lube oil is critical and will effect the bearings made of white metal causing pressure loss to the exchange towers. In such cases, the contaminated oil cannot be used in the lube oil system and has to be rejected. The rate of rejection may be around 200 to 400 Liters per day which cannot be reused and the oil is difficult to dispose off due to the toxicity and environmental problems of H2S gas. Thus, large quantities of oil is to be rejected due to the contamination of H2S gas which is not economically feasible. When H2S gas dissolves in oil it causes formation of Mercaptans also. This patent covers reclamation and regeneration of used oil. During the process of dissolution of H2S in oil, there is a possibility of elemental sulphur and Mercaptan sulphur formation due to the oxidation caused by ingressed oxygen. The formation of Mercaptan Sulphur and other forms of Sulphur cause corrosion and damage to the copper containing components. AB Nynaes Petroleum in their publication WO 071363401-A1. and Marine oil technology in their publication EP 1059988-B1, deals with general lubricants not specific to oil contaminated with H2S gas. Corex Technologies in their publication WO9600273-A1 process for the reclamation of used lubricating oils. The following patents which are reported, deal with general reclamation methods for lubricating oils, light Petroleum distillates and LPG. They are not relevant to the present patent being filed. Nalco chemical company in their publication EP0617991B1, A1 & US6082982 'On method of recovering oil from waste oil fluids'. Adfiltech US 5330636 'Apparatus for reconditioning of hydrocarbon fluids'. Opcon Inc US4769147 'Oil reclamation apparatus'. Budny, Rick R US 4681660. 'Method and Device for reclaiming fluid lubricants' Rosser Frank S US 6082982 deals with reclamation of compressor refrigerant. 'CBM oil reclamation systems incorporated US 4515684 oil reclamation process and apparatus there for. Separator EC C10M175/00F an improvement process and apparatus for the reclamation of used lubricating oil. US Patent no. 5135616 on 'Oil purification deals with packed column method for collecting and purification of oil for removal of lighter fractions of oil'. US Patent No. 5332507 deals with recovery of oil from recycling of waste oil fluids by removing solids and emulsion water. US Patent No. 6485632B1 'Apparatus and method for waste oil deals with recovery waste oil to make it suitable as fuel for diesel engine through filtration'. US Patent No. 5944034 'Apparatus and method for recycling oil laden waste materials through vapoursing condensation'. US Patent No. 7022240 'Method and apparatus for on-site treatment of oil and gas well waste fluids'. US Patent 6565740 'Process for sweetening of LPG, Light petroleum distillates by liquid-liquid extraction using metal phthalocyanine sulphonamide catalyst'. In addition to the above, the following patents have also been referred which mostly deal with reclamation of combustion engine oils and adopt different treatment procedures. WO07136340, US 5330636, GB 318626, GB 284327, US 4769147, US 4681660, US 5314613, US 5135616, US 5332507, US 6139725, US 5824211, US 5630956, US 5556548, US 5286380, US 5242034, US 5240593, US 4443334, US 4330038, US 4289583, US 4227969, US 4189351, US 5776315 and US 4943352. None of the Patents cited herein above teaches the method of the present invention. OBJECT OF THE INVENTION: An object of this invention is to propose a process for the removal of H2S & Mercaptan Sulphur from the used compressor oils; Another object of this invention is to propose a process for the removal of H2S & Mercaptan Sulphur from the used compressor oils for recycling; Further, object of this invention is to propose a process for the reclamation and regeneration of used compressor oils. SUMMARY OF THE INVENTION: According to this invention there is provided a process for removal of H2S and Mercaptans sulphur from compressor oil comprising: adding adsorbents under heating in presence of nitrogen bubbling for a certain period of time with stirring; subjecting the oil thus obtained to the step of filtration. In accordance with this invention there is also provided a process as claimed in the proceeding claim wherein 20 wt% of dried molecular sieves 13 X is added to compressor oil and heated to 90°C with nitrogen bubbling for 2 hours with stirring are treated with 99.9% electrolytic grade copper powder and the temperature is increased to 100°C for 2 hrs and then filtered. Further, in accordance with this invention there is provided a process for removal of H2S & Mercaptans from compressor oil by heating to a temperature of 90 to 120°C in the presence of electrolytic grade copper powder or mixture of copper and silver powders DESCRIPTION OF THE INVENTION: In petroleum industry, the H2S contamination is usually removed by caustic wash which is very effective and cheaper but caustic wash cannot remove the Mercaptans and free sulphur formed during the reaction with H2S gas. Further alkali treatment may remove the additives which are generally added to improve the performance of oil. Hence various reclamation processes were studied to remove the contaminants from oil so as to make it reusable. Keeping in view of the scaling up of the processes and economy of regeneration, different adsorbents such as animal charcoal, fullers earth, neutral alumina, molecular sieves, were tried in different combinations to achieve the goal of removal of H2S and Mercaptans below the instrument detection level as per the methods given. With the combination of different adsorbents, the treatment process can be scaled up continently to suit the batch size by designing columns with proper bed material as experimented in our processes. In this process the used oil is heated to 90°C with nitrogen bubbling for 1 to 2 hours and then the oil is treated with electrolyte grade copper powder (20% by weight) at 120°C and stirring and filtered. The filtered oil is treated with neutral alumina at temperature of 60 to 70°C filtered. The contaminants like H2S Mercaptan Sulphur and elemental Sulphur were determined. When the treated oil is tested, it is found to be free from H2S, Mercaptan and elemental Sulphur. Experiments were also conducted with mixture of Copper and Silver powders (15 and 5% by weight). There is improvement in the color of the oil and the oil has become more clear. The contaminated oil is degassed under vacuum for 2 to 4 hours at 60 to 80°C with stirring. The oil is then treated with dried animal charcoal (5 to 10%) and fullers earth (Korvi earth) (5 to 10%) and filtered. The filtered oil is tested for H2S, merchantman sulphur and elemental Sulphur. The contaminated oil is bubbled with nitrogen gas at 120, 240, 360 ml/minute for 2 to 4 hours at 80 to 100°C and then treated with animal charcoal (5 to 10%) followed by fullers earth (5 to 10%) The contaminated oil is bubbled with nitrogen gas and treated with neutral alumina followed by animal charcoal and fullers earth The contaminated oil is treated with molecular sieve 13 X at room temperature to remove H2S gas and then subsequently treated with neutral alumina, animal charcoal and fullers earth to remove the Mercaptans, acid contaminants, moisture and to improve colour. The advantage of using molecular sieve 13X is to regenerate H2S gas by heating molecular sieves to 150° C. Thus, the H2S gas is recovered and reused. This process is usefull in a continuous process after scaling up by using a column with a bed of molecular sieves. The molecular sieves has got the capability adsorbing 50 g of H2S gas per Kg of molecular sieves. The oil is treated with molecular sieve 13 X with stirring and then treated with electrolytic copper powder at 100°C with stirring for 2 to 4 hours and then filtered. The filtered oil is treated with animal charcoal (5 to 10%) followed by neutral alumina (2 to 4%) and fullers earth. The physical and chemical properties of oil before processing and after processing by the above methods are determined. The H2S was tested by IP 342/93 method by treatment with Cadmium Sulphate. The qualitative presence of Mercaptans were determined by ASTM D 4952 (Doctors test). The quantitative estimation of Mercaptan and H2S were determined by potentionmetric method using silver-silver sulphide electrode with nitrogen purging and by titrating the oil sample in a solvent like Isopropanol as per UOP 163-89. Further, the process of the present invention will be described in greater details with the help of the examples: Treatment with Copper, Silver powders and other adsorbent materials The treatment of the oil by the process given under 3.1, though effective, it causes oil to become dark in color, and the acid values are comparatively higher as compared to the other process. Treatment of oil given under 3.2 to 3.6 can effectively remove the Mercaptans and elemental Sulphur and the process is safe to handle as the reaction temperature is on lower side. Example-1 Oil C (Process-1): 100 g of compressed oil containing H2S and Mercaptan is taken in a beaker and heated to 90°C with Nitrogen bubbling for 2 hours under stirring. The oil is then treated with 20 g of 99.9% pure electrolytic grade copper powder under stirring. The temperature of the oil is slowly increased from 90 to 120°C over a period of one hour and the temperature is maintained at 120°C for 2 hours with stirring. At the end of 2 hours the stirring is stopped, the oil is allowed to settle and then filtered hot through a sintered glass crucible (G4) under vacuum. The colour of the oil is found to be dark brown. The physical and chemical properties of the oil after treatment are determined and are given in table-1. Example-2 Oil D (Process-2) 100 g of compressed oil containing H2S and Mercaptan is taken in a beaker and heated to 90°C with Nitrogen bubbling for 2 hours under stirring. The oil is then treated with 15 g of 99.9% pure electrolytic grade copper powder and 5 g of 99.9% silver powder under stirring. The temperature of the oil is slowly increased from 90 to 120°C over a period of one hour and the temperature is maintained at 120°C for 2 hours with stirring. At the end of 2 hours the stirring is stopped the oil is allowed to settle and then filtered hot through a sintered glass crucible (G4) under vacuum. The oil is found to be clear and dark brown in colour. The physical and chemical properties of the oil after treatment are determined and are given in table-2 Example-3 Oil E (Process-3): 100 g of the compressor oil containing H2S and Mercaptan is taken in a 2 necked round flask with a paddle for stirring. One neck is connected to a vacuum pump through a trap. The oil is heated to 60°C under vacuum at 2 mm of Hg for 2 hours with constant stirring. At the end of 2 hours, 5 g of previously dried animal charcoal is added slowly for period of 20 minutes through a separating funnel under stirring maintaining the vacuum and temperature. The stirring is continued for 30 minutes. 10 g of fullers earth (korvi earth) previously dried for 24 hours at 105°C is added slowly through a separating funnel for 20 minutes under stirring maintaining temperature and vacuum. The temperature of the oil is increased to 80°C and maintained for 2 hours with stirring. The stirring is stopped after 2 hours and the oil is filtered through a buckner funnel with a filter paper under vacuum. The physical and chemical properties of the oil is determined and are given in table-3 Example-4 Oil F (Process-4): 100 g of the compressor oil containing H2S and Mercaptans is taken in a 2 necked round flask with a paddle for stirring. One neck is connected to a nitrogen cylinder for sparging nitrogen gas. The oil is heated to 80°C under nitrogen bubbling at the rate of 360 ml/min for 2 hours with constant stirring. At the end of 2 hours, 5 g of previously dried animal charcoal is added slowly for periord of 20 minutes through a separating funnel under stirring maintaining the temperature. The stirring is continued for 30 minutes, 10 g to fullers earth (korvi earth) previously dried for 24 hours at 105°C is added slowly through a separating funnel for 20 minutes under stirring maintaining temperature and Nitrogen. The temperature of the oil is increased to 90°C and maintained for 2 hours with stirring. The stirring is stopped after 2 hours and the oil is filtered through a buckner funnel with a filter paper under vacuum. The physical and chemical properties of the oil is determined and are given in table-4 Example-5 Oil G (Process-5): 100 g of the compressor oil containing H2S and Mercaptan is taken in a 2 necked round flask with a paddle for stirring. One neck is connected to a nitrogen cylinder with flow controller for sparging nitrogen gas. The oil is heated to 80°C under nitrogen bubbling at the rate of 360 ml/min for 2 hours with constant stirring. At the end of 2 hours, the 5 g of previously dried neutral alumina is added slowly for period of 20 minutes through a separating funnel under stirring maintaining the temperature. The stirring is continued for 30 minutes. 10 g of fullers earth (korvi earth) previously dried for 24 hours at 105°C is added slowly for 20 minutes under stirring maintaining temperature and Nitrogen. The temperature of the oil is increased to 90°C and maintained for 2 hours with stirring. The stirring is stopped up to 2 hours and the oil is filtered through a buckner funnel with a filter paper under vacuum. The physical and chemical properties of the oil is determined and are given in table-5. Example-6 Oil H (Process-6): 100 g of the compressor oil containing H2S and Mercaptans is taken in a 2 necked round flask with a paddle for stirring. 20 g of previously dried molecular sieve 13 X is added slowly at room temperature with stirring for a period of 2 to 4 hours. At the end of 4 hours, the oil is filtered. The filtered oil is heated to 80°C under nitrogen bubbling at the rate of 360 ml/min for 2 hours with constant stirring. At the end of 2 hours, the 5 g of previously dried neutral alumina is added slowly for period of 20 minutes through a separating funnel under stirring maintaining the temperature. The stirring is continued for 30 minutes. 10 g of fullers earth (korvi earth) dried for 24 hours at 105°C is added slowly for 20 minutes under stirring maintaining temperature and Nitrogen. The temperature of the oil is increased to 90°C and maintained for 2 hours with stirring. The stirring is stopped after 2 hours and the oil is filtered through a buckner funnel with a filter paper under vacuum. The physical and chemical properties of the oil is determined and are given in table -6. Example-7 Oil I (Process-7): 100 g of compressed oil containing H2S and Mercaptans is taken in a beaker and treated with 10 g of molecular sieve 13 X and then heated to 90°C with Nitrogen bubbling for 2 hours under stirring. The oil is then treated with 20 g of 99.9% pure electrolytic grade copper powder under stirring. The temperature of the oil is slowly increased from 90 to 100°C over a period of one hour and the temperature is maintained at 100°C for 2 hours with stirring. At the end of 2 hours the stirring is stopped, the oil is allowed to settle and then filtered hot through a sintered glass crucible (G4) under vacuum. The colour of the oil is found to be brown. The physical and chemical properties of the oil after treatment are determined. Since the colour is dark brown and the acid value is high the process adopted under Example-4 is applied to remove the acids and also to remove any traces of Mercaptans present in the oil after treatment. The oil is heated to 80°C under nitrogen bubbling at the rate of 360 ml/min for 2 hours with constant stirring. At the end of 2 hours, the 5 g of previously dried animal charcoal is added slowly for period of 20 minutes through a separating funnel under stirring maintaining the temperature. The stirring is continued for 30 minutes. 10 g of fullers earth (korvi earth) dried for 24 hours at 105°C is added slowly for 20 minutes under stirring maintaining temperature and nitrogen sparging. The temperature of the oil is increased to 90°C and maintained for 2 hours with stirring. The stirring is stopped after 2 hours and the oil is filtered through a buckner funnel with a filter paper under vacuum. The physical and chemical properties of the oil is determined and are given in table-7. The properties obtained after subjecting H2S contaminated oils to different treatment processes as compared to fresh oil and H2S saturated site oils are given in Table-8. In the model experiments H2S free compressor grade oil is taken and saturated by bubbling H2S gas and then subjected the oil by the above treatment methods. The H2S presence is tested by adding cadmium sulphate which did not show any precipitate indicating the absence of H2S. Similarly Mercaptan free compressor oil is mixed with known concentrations of Octadecylmercaptan or ethyl Mercaptan and subjected the oil to the above processes to find out the efficiency of the method for total removal of Mercaptan as indicated by Doctors test. The RBOT value of the treated oil is comparable with fresh oil indicating that the performance additives are not lost or depleted during the treatment. The debris after removal of impurities can be disposed off by incinerating. WE CLAIM: 1. A process for removal of H2S and Mercaptans sulphur from compressor oil comprising: adding adsorbents under heating in presence of nitrogen bubbling for a certain period of time with stirring; subjecting the oil thus obtained to the step of filtration. 2. The process as claimed in claim 1, wherein the said adsorbents are selected from animal charcoal fullers earth, neutral alumina, molecular sieves, copper powder, silver powder and mixtures thereof. 3. The process as claimed in claim 1, wherein the oil is heated to a temperature of 90 to 120°C 4. The process as claimed in claim 1, wherein the nitrogen bubbled for 1 to 2 hours under stirring. 5. The process as claimed in claim 1, wherein nitrogen gas is bubbled at 80°C at the rate of 360 ml/min for 2 hours and treated with 5 wt% animal charcoal and 10 wt% fullers earth at 90°C and maintaining temperature for 2 hrs and filtration. 6. The process as claimed in claim 5, wherein instead of 5 wt% animal charcoal 5 wt% dried neutral alumina at 80°C is used. 7. The process as claimed in claim 5, wherein 20 wt% of dried molecular sieves 13 X at room temperature is added to the compressor oil under stirring for 4 hours. 8. The process as claimed in the preceeding claims wherein 20 wt% of dried molecular sieves 13X is added to compressor oil and heated to 90°C with nitrogen bubbling for 2 hrs with stirring and treated with 99.9% electrolytic grade copper powder and the temperature is increased to 100°C for 2 hrs and the filtered. 9. A process for removal of H2S and Mercaptans from compressor oil by heating to a temperature of 90 to 120°C in the presence of electrolytic grade copper powder or mixture of copper and silver powders. ABSTRACT Title: Treatment processes to remove hydrogen sulphide and mercaptan sulphur from used compressor oils for salvaging and recycling. A process for removal of H2S and Mercaptans sulphur from compressor oil comprising: adding adsorbents under heating in presence of nitrogen bubbling for a certain period of time with stirring; subjecting the oil thus obtained to the step of filtration.

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00766-kol-2008-abstract.pdf

00766-kol-2008-claims.pdf

00766-kol-2008-correspondence others.pdf

00766-kol-2008-description complete.pdf

00766-kol-2008-form 1.pdf

00766-kol-2008-form 2.pdf

00766-kol-2008-form 3.pdf

00766-kol-2008-gpa.pdf

766-KOL-2008-(13-07-2012)-CORRESPONDENCE.pdf

766-KOL-2008-(19-12-2011)-ABSTRACT.pdf

766-KOL-2008-(19-12-2011)-CLAIMS.pdf

766-KOL-2008-(19-12-2011)-CORRESPONDENCE.pdf

766-KOL-2008-(19-12-2011)-DESCRIPTION (COMPLETE).pdf

766-KOL-2008-(19-12-2011)-FORM-1.pdf

766-KOL-2008-(19-12-2011)-FORM-2.pdf

766-KOL-2008-ABSTRACT.pdf

766-KOL-2008-CLAIMS.pdf

766-KOL-2008-CORRESPONDENCE 1.1.pdf

766-KOL-2008-CORRESPONDENCE.pdf

766-KOL-2008-DESCRIPTION (COMPLETE).pdf

766-KOL-2008-FORM 1.pdf

766-KOL-2008-FORM 18 1.1.pdf

766-kol-2008-form 18.pdf

766-KOL-2008-FORM 2.pdf

766-KOL-2008-FORM 3.pdf

766-KOL-2008-GPA.pdf

766-KOL-2008-GRANTED-ABSTRACT.pdf

766-KOL-2008-GRANTED-CLAIMS.pdf

766-KOL-2008-GRANTED-DESCRIPTION (COMPLETE).pdf

766-KOL-2008-GRANTED-FORM 1.pdf

766-KOL-2008-GRANTED-FORM 2.pdf

766-KOL-2008-GRANTED-SPECIFICATION.pdf

766-KOL-2008-REPLY TO EXAMINATION REPORT 1.1.pdf

766-KOL-2008-REPLY TO EXAMINATION REPORT.pdf

766-KOL-2008-SPECIFICATION.pdf