http://localhost:8081/jspui/handle/123456789/36 2025-07-01T00:28:36Z http://localhost:8081/jspui/handle/123456789/15785 Title: PROPYLENE SEPARATION FROM GASEOUS STREAMS BY PRESSURE SWING ADSORPTION Authors: Divekar, Swapnil Abstract: Propylene (or Propene) is the earliest raw material used for industrial-scale production of a petrochemical. It was used for the production of isopropanol over 60 years back. In modern petrochemical complexes, Propylene finds multiple applications for the production of various major petrochemical derivatives like polypropylene, acrylonitrile, cumene, etc. as well as value additions of fuel like gasoline to improve its octane rating. Propylene has registered steady growth in terms of production volume and is the second largest petrochemical produced by volume. The importance of propylene as a feed stock is evident from its usage as a precursor to numerous petrochemicals. A concise summary of the propylene production process including basic principles, brief process description and details of the main process licensors are included in the introductory chapter. This chapter also gives a brief account of conventional propylene-propane separation techniques as well as the alternative approaches reported in the literature. Despite being such an important petrochemical, propylene is mostly produced as a byproduct as it is generated in sufficient amounts in the production of ethylene by steam cracking and Fluid Catalytic Cracking (FCC) processes. Steam cracking and FCC accounts for 56 and 20% of the world’s propylene production. The C3 (Propane-Propylene) fraction from the off-gases of these units are separated in propylene and propane rich streams by distillation. Separation of propylene and propane is a very energy intensive process in petroleum refineries and petrochemical industries, requiring large cryogenic distillation columns with 75-90 m height and 2-6 m diameter operating at a temperature of 240 K and a pressure of ~310 kPa with over 200 theoretical stages and a very high reflux ratio (R~10) due to low relative volatility of propane with respect to propylene. This separation becomes challenging because propylene and propane molecules have very similar properties e.g. Close boiling point (-42 and -47.6 °C), molecular weight (44 and 42 g/mol respectively), polarizability (6.29 and 6.26 10-24 cm3), kinetic diameter (0.40 and 0.43 nm) respectively. Propylene recovery is also desirable from the propane rich bottom product of propane-propylene splitter (distillation column). This product is used for fuel application and may contain 5-15% propylene. The recovery of propylene from this stream is desirable as propylene may cause problems of engine and injector deposits and also due regulatory ABSTRACT III specifications on maximum propylene content in fuel grade propane in countries like USA. E.g., the maximum allowable propylene content in HD-5 and HD-10 grades of propane is 5 and 10% respectively in the USA. Another instance of need for propylene recovery is from gas-phase polypropylene production units. Polymerization of propylene results in solid polymer product containing inter particle monomer. Before pelletization, the solid polymer phase is purged with nitrogen to recover the monomer. The propylene content of this product purge gas may reach up to 50%. Recovery and recycling of propylene is economically beneficial. There is a need for an economically viable method for recovering valuable olefin monomer from nitrogen purge gas and recovering nitrogen with satisfactory recovery and purity. A number of alternative separation processes have been proposed including membrane separation using highly selective membranes, absorption, adsorption and its variants like adsorption-distillation hybrid systems and pressure swing adsorption (PSA) or Vacuum Swing Adsorption (VSA). The overall objective of the present work is to pursue and describe the adsorptive studies on separation of propylene from propylene bearing streams by experimental Pressure Swing Adsorption (PSA) for binary mixtures arising from: (i) Steam Cracking of hydrocarbons (~50% propylene + balance propane) (ii) Fluid catalytic cracking (~75% propylene + balance propane) (iii) Propane-propylene splitter bottom (5-15% propylene + balance propane) (iv) Polypropylene reactor purge gas (10-50% propylene + balance Nitrogen) The scope of experimental studies undertaken include:  Comprehensive literature survey to identify the adsorbents, process operating conditions and PSA process configuration and to know the experimental results for benchmarking purpose  To characterize and evaluate different adsorbents by:  Structural properties  Single component equilibrium isotherm data ABSTRACT IV  To develop an Ideal Adsorbed Solution Theory (IAST) based solver to predict the binary isotherm data and solver validation and  To evaluate binary adsorption equilibrium data based on IAST solver  To conduct experimental dynamic PSA studies to explore the applicability of recovery of propylene from above-identified feed streams An exhaustive literature survey reveals that many adsorbents including metal organic frameworks (MOFs), zeolites, Na-ETS-10 and π- complexation adsorbents have been reported in the literature for propylene-propane separation. The Experimental adsorption data for propane-propylene binary adsorption is scantily available in open literature due to requirement of measurement set up, precise analytical facility and the considerable time taken in these measurements. The available experimental or predicted binary data for commercial zeolites (13X and 5A) from different manufacturers is limited to 100kPa pressure. Practical applications isotherm data for higher partial pressure will be required. A comprehensive evaluation of the applicability of these adsorbents as an adsorbent for PSA/VSA process on the basis of such scant data is difficult as the operating pressures of PSA/VSA process are higher than this pressure range. Ideal Adsorbed Solution Theory (IAST) is a powerful tool to predict the performance of an adsorbent on the basis of competitive multicomponent adsorption prediction. An IAST based solver was developed and validated against the literature reported data for prediction of binary adsorption of propylene-propane and propylene-nitrogen mixtures. The binary adsorption data was predicted for a temperature and pressure range 303-423 K and 0-500 kPa. The IAST predicts high propylene selectivity over both propane and nitrogen. Three adsorbents including laboratory synthesized adsorbent Na-ETS-10 and commercial adsorbents namely zeolite 13X (Z10-04), zeolite 5A (UOP) were tested for their applicability for selective propylene adsorption from propylene containing streams (propylene-propane and propylene-nitrogen mixture). The screening was conducted by equilibrium adsorption isotherm, and binary adsorption predicted based on the IAST theory. Among the commercial adsorbents, Zeolite 13 X showed the highest capacity for propylene adsorption and also the propylene-propane and propylene-nitrogen selectivity calculated on the basis IAST. In the case of laboratory synthesized adsorbents Na-ETS-10, the results obtained over different batches of adsorbent was not consistent and reproducible. During initial attempts, ABSTRACT V the adsorbent was co-formed with impurities of Quartz phase. The synthesis procedure was modified by different synthesis procedures reported in the literature and ultimately the synthesis procedure optimized to get consistent pure Na-ETS-10 phase formation. It was however felt that further scale-up of this adsorbent for adsorptive process development might itself take significant time. The experimental data generated for propylene-propane and propylene-propane generated has been compared on the basis of key process performance indicators like purity, recovery and productivity of propylene with a single column six step VSA cycle. Effect of operating parameters like feed flow rate, adsorption temperature, adsorption pressure and adsorption time etc have been studied to identify favorable operating conditions. The experimental results of this thesis suggest that propylene can be recovered in refinery grade purity from a mixture containing 15 mol % propylene in propane. This type of propylene recovery work from dilute streams has not been reported elsewhere. Simultaneous propylene and nitrogen recovery from polypropylene reactor purge gas which may contain up to 50% propylene was experimentally studied. A very high purity nitrogen product was recovered at recovery values of over 60 mol%. A preliminary economic analysis indicates that the recovery of high purity nitrogen presents attractive monitory benefits. The recovered propylene can also be used as a feed stock to alkylation process within refinery and petrochemical complex. 2019-08-01T00:00:00Z http://localhost:8081/jspui/handle/123456789/15784 Title: STUDY ON STABILITY OF ASA EMULSION FOR SIZING OF PAPER Authors: Kumar, Ashish Abstract: In alkaline papermaking process, use of alkenyl succinic anhydride (ASA) for internal sizing of paper is continuously increasing. ASA imparts sizing to paper quicker than that imparted by alkyl ketene dimer (AKD). Cationic starch (CS) is the conventionally used stabilizer for ASA emulsification. There are two main reasons that restrict the wide spread use of ASA during papermaking, (a) low shelf life of ASA emulsion (b) the sticky conduct of hydrolyzed ASA. The available literature indicates that the shelf life of ASA emulsion can be achieved up to about 4 hours by using different protective colloids. Few references are available of the literature on the effect of different pulp furnishes and fillers on the sizing efficiency of ASA emulsion prepared by using polymers other than CS and the stabilizing effect of different protective colloid is scanty. The objectives of the present study are as follows:  To study the possibility of enhancing the shelf life of ASA emulsion prepared by using different polymers.  Study the effect of ASA emulsions prepared by using different polymers on mixed hardwood, bagasse and recycled pulps along with different fillers. The study has been presented in eight chapters. Introduction was provided in chapter 1 of this thesis in which the factors influencing the quality and stability of ASA emulsion were explained including the concept of internal sizing. The stability mechanism was discussed followed by problem statement and the objectives of this thesis. So, meticulous study was required to examine the impact of different protective colloids on hydrolysis of ASA emulsion at varying ratios of ASA to stabilizer beyond the already reported time period. It was equally essential to study the impact of ASA emulsion prepared by using different protective colloids using different pulp furnishes and fillers. Literature review was included in chapter 2 on the issues with the ASA sizing viz. low shelf life of ASA emulsion and the sticky behavior of hydrolyzed ASA. This chapter provided the overview of main sizing processes reported in literature with their merits & demerits. The various methods for the measurement of sizing degree followed by stabilization and destabilization phenomenon of an emulsion have been discussed at the beginning of this chapter. Different polymers which iv enhance the stability of ASA particles and their interaction with ASA molecules have been mentioned & discussed. Keeping in view the diversity of raw material i.e. pulp furnishes, it further elaborates, the sizing behavior of different pulps and fillers for paper making. Finally national and international status of the work carried out for the enhancement of ASA emulsion stability and the future prospects have been prospected. The thorough understanding and mastery of the underlying stability mechanism of ASA molecules will be premise of the research and applications of highly stable ASA emulsion by the papermakers. The experimental part was discussed in chapter 3 in which the details of raw materials and various commercial & laboratory grade chemicals were mentioned. Various methods followed for the characterization of chemicals, process water and pulps & the methods of ASA emulsification were discussed. Various measurement techniques viz. determination of particle size distribution, infrared spectroscopic analysis, measurement of hydrolysis content of ASA, imaging analysis of ASA emulsions and infrared spectroscopic analysis of handsheets along with details of the instruments used were also mentioned. The methods for the measurement of sizing and physical/ strength properties of handsheets were also discussed at the end of this chapter. The stability mechanism and sizing performance of ASA emulsion stabilized by polyvinylamine (PVAm) macromolecules using different pulps viz. mixed hardwood (MHW), bagasse (BBS), recycled (RCL) and fillers viz. talc, ground calcium carbonate (GCC) & precipitated calcium carbonate (PCC) were discussed in chapter 4. Emulsion stability was achieved even with low dosage of vinylamine polymer as 2.5% of ASA as compared with the required dose of cationic starch at 200% of ASA. Interaction between carbonyl group of ASA and amine group of polyvinylamine was confirmed by FTIR spectra of ASA emulsion prepared by PVAm which might attribute to formation of N-alkyl acid amide by the reaction between carbonyl group of ASA and amine group of PVAm. ASA emulsion stabilized with PVAm was found to be stable at broader range of pH and temperature. Better sizing performance was observed with BBS pulp followed by RCL pulp and MHW pulp. It was evident from the crystallinity ratios (Cr.R.1 and Cr.R.2) and value of H-bond energy that BBS pulp has the maximum amorphous region in the cellulosic fiber that may possibly be translated into lesser chemical requirement to attain the same properties like Cobb60, contact angle followed by v RCL pulp and MHW pulp. Superior sizing was observed with talc filler followed by GCC and PCC filler. The sizing performance of ASA emulsion stabilized by polyacrylamides macromolecules was discussed in chapter 5. The required dose for PAM-2 was about 5% of ASA and that for PAM-1 was about 10% of ASA to form stable emulsions up to 4 hours and 3 hours, respectively since their preparation. Emulsions started losing the stability on further increasing the time period. The greater stabilizing efficiency of PAM-2 was possibly due to its higher molecular weight (1.87x1012) than the molecular weight of PAM-1(6.12x1011). The interaction between PAM and ASA molecules was confirmed by the FTIR spectroscopic analysis. The behavior of PAM stabilized ASA emulsion with different pulps and fillers was found in good agreement with that of PVAm stabilized ASA emulsion. In 6th chapter, poly-DADMAC was used as stabilizer for ASA emulsification at various ratios of ASA to poly-DADMAC. It provided stability to ASA emulsion up to 3 hours even at very low dose of poly-DADMAC (2.5% of ASA). Being a high charge density material it neutralized the cationic charge demand of the paper making stock to a great extent and adversely affected the sheet formation as observed visually. The study was extended to determine the effect of different fillers using MHW pulp on the performance of poly-DADMAC stabilized ASA emulsion but no positive effect was observed for the improvement of sizing properties and formation of handsheets. The effect of different ions present in process water on performance of polyvinylamine based ASA emulsion was discussed in chapter 7. PVAm-2 diluted with de-ionized water produced a stable ASA emulsion while poor emulsification was observed by using the process water for the dilution. So, the fresh water was examined to determine the level of various ions present in it, which restricted the emulsification. This chapter deals with the study on effect of different ions viz. Ca2+, Mg2+, Cl−, SO4 2- & HCO3- present in process water on the performance of ASA emulsion prepared by using PVAm-2 as stabilizer. The concentration of calcium ions was found to be higher and of Mg2+ ions was less than that of maximum permissible limit which may be responsible for the poor emulsification of ASA. It was also observed that chloride ions adversely affected while bicarbonate ions assisted the ASA emulsification. Papermakers can characterize process water before using in ASA emulsification in order to know the level of various ions vi present, as the study has provided the information about the individual effect of various ions present in process water. The 8th chapter included the conclusion of this thesis by including the results, major achievements along with recommendations for future scope in this field. The research objectives mentioned in chapter 1 were effectively achieved by the experimental work. ASA emulsions prepared with both PVAms were found to be stable up to about 4 hours even with low dosage of vinylamine polymer. The PAM- 1 & PAM-2 stabilized ASA emulsions were found to be stable up to 3 hours and 4 hours, respectively. Interaction of PVAms and PAMs were confirmed through FTIR spectroscopic analysis. Poly-DADMAC was not found an efficient stabilizer for application in paper sizing. The study conducted with different furnishes showed better sizing with BBS and RCL pulp than MHW pulp. It was observed from the crystallinity ratios (Cr.R.1 and Cr.R.2) and the energy of H-bonds that BBS pulp has the maximum amorphous region in the cellulosic fiber that might possibly be translated into less chemical requirement to attain the same properties like Cobb60, contact angle followed by RCL pulp and MHW pulp. Superior sizing was observed with talc filler followed by GCC and PCC filler. PVAm diluted with deionized water produced a stable ASA emulsion while poor emulsification was observed by using the process water for the dilution of PVAm. The concentration of calcium ions was higher in process water than the maximum permissible limit which may be responsible for the poor emulsification of ASA. It was also observed that chloride ions adversely affected while bicarbonate ions assisted the ASA emulsification. Future research efforts should be made to develop the protocol to use the process water for the preparation of ASA emulsion utilizing various polymers as studied above for commercial applications and papermakers can characterize process water before using in ASA emulsification in order to know the level of various ions present, as the study has provided the information about the individual effect of various ions present in process water. The study further opens up the research scope to enhance the stability of ASA emulsion by using various other stabilizers or blends of various stabilizers so that the emulsion can be transported as ready to use emulsion to eliminate the in situ emulsification of ASA and to find out others mechanisms of various pulps for the varying chemical dose requirement to get the same sizing properties. 2020-01-01T00:00:00Z http://localhost:8081/jspui/handle/123456789/15302 Title: ELECTROCOAGULATION TREATMENT OF PULP AND PAPER INDUSTRY WASTEWATER AND ITS RECYCLING POTENTIAL Authors: Kumar, Dushyant Abstract: The pulp and paper industry (PPI) is well known for the consumption of tremendous volume of fresh water and subsequent generation of large volume of wastewater. The wastewater consists of significant amount of degraded lignin products, intense color, chlorophenols and several other toxic contaminates with limited biodegradability. These toxic organic compounds are not easy to treat with conventional treatment processes. Henceforth, wastewater treatment technologies require improvements in order to meet the strict effluent discharge standards and to make it cost effective processes. Electrocoagulation (EC) method is a versatile, clean and an advanced oxidation process can be a promising and effective treatment option for the reduction of organic contaminate present in the industrial wastewater. As India is a tropical country and having enormous solar energy potential this can be easily utilized as a source of power for the treatment of wastewater operated by EC method. In this study, pulp and paper industry wastewater (PPIW) after primary treatment was subjected to physicochemical and environmental characterization in terms of biochemical oxygen demand (BOD), chemical oxygen demand (COD), total organic carbon (TOC), color, solids, and chlorophenolics prior and after the treatment. Four types of electrodes such as aluminum, mild-steel, stainless steel (SS)-304 and SS-316 were used to treat the effluent. The electrodes metal coupons were prepared for immersion test according to ASTM standard method to detect the effect of corrosion on the electrodes surface. These coupons were immersed in PPIW for a long time about 185 day’s exposure. The corrosion rate were observed in decreasing order as mild steel > aluminum > mild steel > SS-304 > SS-316. For the determination of optimum treatment conditions for EC treatment, the influences of various process variables i.e. pH, current density, treatment time, a dose of electrolytes were observed on the basis of maximum COD and color removal. The reduction efficiency for the parameters such as BOD, TOC, total dissolved solids and chlorophenols were determined under optimum conditions. Extraction and derivatization of chlorophenols compounds from wastewater has been performed prior and post EC treatment and finally analyzed by GC-MS. Qualitative and quantitatively estimation were done on the basis of retention time and peak area respectively of particular compound. The EC treatment method was found to be highly effective for color removal with all four electrodes. In case of Al, MS, SS-304 and SS-316 electrode color was removed 98%, 94%, 99.8% and 99.6%. Reduction in COD, color, BOD/COD ratio and chlorophenolics were observed in decreasing order according to electrode material such as SS-304 > SS-316 > aluminum> mild steel. COD reduction was observed 70%, 68% 82% and 81% in respect of Al, MS, SS-304 and SS-316 3l3cctrodes. The biodegradability ii index of the effluent improved up to (0.4-0.55) after the EC treatment in respect of all electrodes. The generated sludge was characterized for various physicochemical parameters using analytical techniques such as field emission scanning electron micrograph coupled with energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis and to understand the physical, chemical and elemental nature of sludge, and find out proper management option. The sludge was found to be non-hazardous and could be used as low cost alternative for several applications such as land application, industry and wastewater treatment. Furthermore, when aluminum electrode was applied for the treatment of wastewater, it was generated considerable amount of Al in the sludge. This Al content was successfully recovered near about 70 % from sludge by using digestion method. Recycling of treated water has been performed in the bleaching process in the laboratory to reduce the freshwater input in PPI. The OD0EpD1 sequence was used for the production of effluent in the laboratory. The produced wastewater was treated under optimum condition. This EC treated water was collected for further use as wash-water in the washing of virgin pulp and in between bleaching stages. In recycling study, two parallel experiments have been done using ODED and DEpD sequences with fresh water and RC_ODEPD and RC_DEpD with EC treated water to examine the recycling potential of EC treated water. To achieve the target brightness of pulp, kappa factor was increased up to (0.25-0.27) in recycling stage and the effect of increased chemical dose was observed on brightness, paper properties and generated effluent quality. The wastewater generated by recycling stage was characterized in terms of BOD, COD, and color and after the re-treatment pollution load was within permissible limit prescribed by central pollution control board on India 2019-03-01T00:00:00Z http://localhost:8081/jspui/handle/123456789/15301 Title: VALORIZATION OF PAPER INDUSTRY LIME SLUDGE, BOILER ASH AND ETP SLUDGE Authors: Vashistha, Prabhat Abstract: The industrial solid waste generation and its stockpile disposal have major environmental consequences. These consequences could be minimized through the solid waste application as a raw material in other industries. The current thesis focusses on application of paper industry solid waste in different applications like nanosilica synthesis, cementitious binder fabrication, application in concrete and methanogenesis. Graphical Abstract Boiler ash is utilized for the synthesis of nanosilica. The particle size of synthesized particles were found in the range of 10-25 nm. . FTIR, TEM and XRD studies confirmed the synthesis of nanosilica. Present study shows about 250 kg of nanosilica can be synthesized per ton of boiler ash with the nanosilica synthesis efficiency of almost 25%. Lime sludge application with nanosilica reduces the temperature of belite synthesis to 1000°C without addition of any chemical stabilizer and pre-calcination whereas conventionally, belite is synthesized above 1200°C. This method of belite based clinker synthesis is energy efficient and ecofriendly. The prepared clinker was mixed with Ground granulated blast furnace slag (GGBS) for the increment in early age strength as belite generally takes part in the development of late strength of concrete. The heat of hydration of developed binder, compressive strength and density of the prepared mortars complies the requirements of indoor and outdoor mortar applications. Lime sludge is also being utilized directly in the concrete with synthesized nanosilica and without ii nanosilica. The purpose was to increase the proportion of lime sludge application in concrete without affecting the compressive strength significantly. It provides a novel and relevant approach for bulk utilization of lime sludge with application of nanosilica synthesized from fly ash. This research will also be relevant for onsite utilization of paper industry boiler ash and lime sludge. It will cut down the transportation expenses of lime sludge and boiler ash disposal or utilization. Application of lime sludge with nanosilica in M25 grade of concrete found suitable. The concrete blocks with 30% application of lime sludge and 1% nanosilica produced sustainable concrete with increased compressive strength. 1% nanosilica addition with lime sludge resulted in 25% increased compressive strength in comparison to the blocks without nanosilica. It provides an edge of the 3 times more application of lime sludge and 30% less consumption of cement in concrete blocks without affecting the compressive strength significantly. The FE-SEM micrographs of concrete with 30% lime sludge and different proportion of nanosilica show a trend of increasing uniformity and microstructure compaction with increasing amount of nanosilica. Study provides a suitable route of value addition and valorization for lime sludge and fly ash. As another route of bulk utilization of lime sludge, it is also utilized with calcination at lower temperature than normal calcination temperature. The lime sludge is calcined at lower temperature of 650° C to convert metakaolinite in kaolinite. The MK (metakaolinite-Al₂O₃.2SiO₂) can make the lime sludge more reactive which makes it perfect raw material to use as cement additive. Al2Si2O5 (OH) 4 = Al2Si2O7 + 2H2O (1) (Kaolinite) (Metakaolinite) Lime sludge calcined at low temperature of 650 °C can be applied productively as a pozzolana with cement. Compressive strength of produced concrete remains intact until 30% application of calcined lime sludge in binder. The pozzolanic behavior of lime sludge is due to the metakaolinite and calcium oxide produced after calcination of lime sludge at 650 0C. These are the sole reasons for increased lime sludge reactivity and accumulation of increased amount of calcium silicate hydrate (CSH) and hydrates of tetra calcium aluminates (TAH). The. Morphological study of concrete and heat of hydration of prepared binder also confirms the increased reactivity of lime sludge. The prepared binder is sustainable with 18% less production cost and emission of greenhouse gases. ETP sludge with cow manure is utilized for biogas production from anaerobic co-digestion (AD). It can stabilize the sludge with energy production at the same time. The AD process was performed at uncontrolled temperature in (450-700 0C) iii mesophilic range, which can be effective for small and medium scale of industries. The aim was to utilize the Paper ETP sludge (PSS) for the AD process and to Co-utilization of PSS with cow manure to check the effect of digestion. The reactor containing PPS only was started to generate biogas on 5th day of the reaction with 7.8% of methane. The cumulative methane yield attained to 13.5 ml/g volatile solid (VS) until day 30. The second reactor containing PPS and cow manure produced methane 134 ml/g VS until day 30. This study presents a more optimized process of anaerobic digestion of paper sludge and co-digestion of paper sludge with cow manure. The utilization of lime sludge and boiler ash of paper industry is recommended as material for construction applications while anaerobic digestion can be used for energy recovery from ETP sludge. These applications will also beneficial for reducing environmental wallop. 2019-07-01T00:00:00Z