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Research Activities on Biodiesel at INDIAN INSTITUTE OF PETROLEUM DEHRADUN - INDIA. Activities on Biodiesel Technology Development. Research activities on process development for Biodiesel (methyl esters) carried out under a sponsored project by Department of Biotechnology, New Delhi
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Research Activities on Biodiesel at INDIAN INSTITUTE OF PETROLEUMDEHRADUN - INDIA
Research activities on process development for Biodiesel (methyl esters) carried out under a sponsored project by Department of Biotechnology, New Delhi • R&D preparation of ethyl esters of Jatropha curcas oil and its field trials on diesel vehicles is being pursued under a collaborative project with MNES, New Delhi. • Studies on bio-diesel from waste cooking oils and greases being carried under a sponsored project by PCRA, New Delhi
Feedstocks for Biodiesel • Biodiesel is prepared from oils and fats. • Oils and fats are composed of molecules called triglycerides. USA : Soya Oil is predominant Europe : Canola, rapeseed oil largely used Other feedstock : Tallow, lard, yellow grease, palm oil Include etc.
Feedstocks in Indian Context • For India non-edible oils obtained from plants which can be grown on waste/ semi arid lands are more suitable. Species can be selected based on the regional climatic conditions • Most of the non-edible oils available in India contains high FFA (2-12%)
Non Edible Vegetable Oils Available in India Possible raw materials for biodiesel Ratanjyot Jatropha curcas Karanja Pongamia glabra Mahua Madhuca indica Pilu Salvadora oleoides Sal Shorea robusta Nahor Mesua ferra linn Kamala Mallotus phillipines Kokam Garcinia indica Rubber Seed Hevea Brasilensis
Feedstocks Tested at IIP for Biodiesel Production • Jatropha curcas • Pongamia glabra • Madhuca Indica • Salvadora Oleoides • Hevea Brasileusis (Rubber seed oil) • Palm stearin • Waste Palm oil • Prinspia Utilis • Sapindus Mukorossi • Soya oil • Rape seed oil • Mixed vegetable oils • Waste grease / oil from restaurants
Commercial Biodiesel Technologies Currently used technologies for producing biodiesel can be classified into three categories: • Base catalyzed transesterification with refined oils • Base catalyzed transesterification with low fatty acid greases and fats • Acid esterification followed by transesterification of lower or high free fatty acid fats and oils. Other process under development include – biocatalyzed transesterification, pyrolysis of vegetable oil/ seeds and transesterification in supercritical methanol.
The goal of all technologies is to produce fuel grade esters meeting standard specifications (e.g. ASTM/ European/BIS). • The key quality control issues involve : • complete (or nearly complete) removal of alcohol, catalyst, water, soaps, glycerine and unreacted or partially reacted triglycerides and free fatty acids (FFA). • Failure to remove these contaminants causes the biodiesel to fail one or more fuel standards.
Basic Process The basic process involves transesterification of vegetable oil/fats in presence of a catalyst in batch or continuous mode. Continuous process may not be suitable, if the variation in quality of feedstocks are wide.
There are numerous variations of basic technology: • Different catalysts e.g. NaOH, KOH, MeONa, Non alkaline catalysts, acids, metal complexes and bio catalysts etc. can be used. • Anhydrous ethanol, isopropanol or butanol can be substituted for methanol. • Alcohols other than methanol may require additional process steps and quality control. • Basic transesterification is carried out at atmospheric pressure and temperature around 60°-70°C. • Some technologies use higher temperatures and elevated pressure, typically in super critical range of methanol. • For high FFA feedstocks – acid catalysed esterification followed by base catalysed transesterification is used or FFA can be removed first and the purified oil is transesterified.
Problems of Biodiesel Production Both base and acid catalyzed processes are associated with several inherent problems: • Free fatty acids interfere with transesterification deactivate the basic catalysts – loss of catalyst and biodiesel yield. • Water deactivates both basic and acidic catalysts. Drying of oil may be required. • Soaps formed with basic catalyst form emulsion and foam and difficult to remove. • When processing feed stocks with high free fatty acids additional steps must be taken. • After basic transesterification, the purification and adequate testing during processing is required to produce fuel grade esters.
Appropriate Technology The selection of appropriate technology for production of biodiesel requires careful selection of processing steps, catalyst and downstream process integration. The quality of feed vegetable oil particularly FFA content plays and important role in identifying the suitable technology.
The important factors to be considered include: • Must be able to process variety of vegetable oils without or minimum modifications. • Must be able to process high free fatty containing oils/ feed stocks. • Must be able to process raw both expelled and refined oil. • Process should be environment friendly almost zero effluents. • Able to produce marketable by products glycerin, fatty acids, soap if any. • Must be able to produce fuel grade esters; Biodiesel produced should meet the standard specifications. • The process should be adaptable over a large range of production capacities.
IIP Processes for Biodiesel India Institute of Petroleum has developed three processes for biodiesel from non-edible oils and under exploited oils including Jatropha curcas, Pongamia, Salvadora, Madhuca Indica and Mixed Oils.
Process – I Base catalysed process: • This process is suitable for feed stocks having FFA content >1% to about 20%. • The oil is pretreated before transesterification at moderate temperature (60-80°C) in presence of a base catalyst. • FFA are also converted to biodiesel resulting in higher yield of biodiesel.
Vegetable oil Oil Pretreatment Methanol + catalyst Transesterification Crude glycerine Crude Biodiesel Methanol recovery Refining Glycerine refining Biodiesel Glycerine IIP Processes for Biodiesel – Process – I
Main Features of IIP Process – I • Flexibility for processing variety of vegetable oils separately or mixed without any modification. • Tolerance of higher levels of free fatty acids • Conversion of free fatty acids present in feed oils to biodiesel or alternatively free fatty acids can be recovered as byproduct or soap. • Biodiesel produced meets the standard specification (ASTM, European or proposed BIS). • Glycerin produced is ~ 99% pure. • Process can be adapted to wide range of production capacities.
Process – II Solid catalyst process: • This process is suited to feed stocks containing wide range of FFA or 100% FFA. • In this process esterification of FFA and transesterification of triglycerides is carried out in a single step over a heterogeneous catalyst at moderate temperature and pressure.
Fresh Vegetable Oil Esterification & Transesterfication Fresh Methanol Methanol Recovery Recycle Methanol BIODIESEL Biodiesel Purification Phase Separation Glycerine Phase Glycerine Refining Glycerine IIP Processes for Biodiesel : Process – II
Main Features of IIP Process – II • Flexibility for processing variety of vegetable oils separately or mixed. • Tolerance of higher levels of free fatty acids. Requires no pretreatment or removal of FFA. • Conversion of free fatty acids present in feed oils to biodiesel. • Tolerance of water in alcohol (aqueous ethanol can be used) Continued...
…IIP Process – II • No emulsion or soap formation • Catalyst is recycled and is not deactivated either with water or FFA. • Biodiesel produced meets the standard specification (ASTM, European or proposed BIS). • Glycerine produced is ~ 99% pure. • Process can be adapted to wide range of production capacities. • The process is ecofriendly with almost zero effluents.
…IIP Process – II Heterogeneous catalyst Process….Technological and economic benefits • Use of heterogeneous catalyst has direct impact on the economics of biodiesel production. • Several neutralisation and washing steps needed for processes using homogeneous catalysts such as NaOH, KOH, MeONa etc. are eliminated. • Associated waste streams are eliminated.
Process – III Base catalyst-solvent process: • This process is suitable for feedstocks having upto about 6% FFA . • Transesterification is carried out at ambient conditions in presence of a base catalyst. After separation of glycerin biodiesel is purified by distillation. • Oil containing higher FFA can also be processed, if a pretreatment step is included. • From technical point of view this process is especially suitable for small scale operations.
Oil Feed Removal of FFA (Optional) Solvent Transesterification Glycerine separation Solvent Recycle Glycerine Biodiesel purification Biodiesel MeOH + Catalyst IIP Processes for Biodiesel – Process – III
Comparison of Biodiesel (IIP Processes) With National & International Specifications
Any of these processes can be selected to produce biodiesel depending upon the characteristics of feed oil stock. Biodiesel produced meets standard specifications (ASTM / European / BIS proposed) by all three processes.
Economics • The cost analysis indicates that the cost of oil is major component (about 75-80 %) of total cost of biodiesel. • Use of lower cost feed stocks would have tremendous impact on biodiesel economics. • Another approach which leads to reduction in operating cost is improvement in technology
Effect of by-products on economics • Market value of glycerol produced as a by-product is an important factor in biodiesel economics. • Glycerol market is limited, any major increase in biodiesel capacity would undoubtedly lead to glycerol prices to decline, thereby affecting the over all economics of biodiesel. • Value addition to oil cake would have greater impact on economics
Economics of Biodiesel production:Effect of Technology improvements -
Corrosion Behaviour of Biodiesel on Diesel Engine Parts • Corrosion behavior of biodiesel produced from various non-edible oils was estimated during long duration static immersion test. • Biodiesel from Mohua & Karanj shows no corrosion on piston metal & piston liner where as salvadora biodiesel has a marked corrosion effect on both the metals indicating that this oil is not suitable for biodiesel production especially when Bharat III & Bharat IV norms will be implemented. • Higher corrosion with salvadora biodiesel is probably due to its high sulfur content, ~ 1600 ppm. • Jatropha curcas has slight corrosive effect on piston liner possibly due to the presence of linoleic acid 18:2 fatty acids.
Corrosion Behavior of Biodiesels on Diesel Engine Parts Using Static Immersion Test for 300 Days
Lubricity of LCO/Diesel - Biodiesel Blends The lubricity behavior of base fuel, Light cycle oil LCO/Diesel and biodiesel blends of Jatropha curcas and Pogamia glabra in LCO were assessed by HFRR test (ISO 12156 method).
Studies on Lubricity Behaviour of Biodiesel-Diesel Blends • Addition of Bio-diesel to diesel / LCO Biodiesel improved the lubricity of diesel and LCO.
Thermoxidative Stability of Biodiesel-Diesel Blends • Thermo-oxidative stability of Biodiesel-diesel blends determined by UOP-413 method. • Biodiesel reduced the sediments thereby suppressed the aging of fuel.
Thermo – Oxidative Stability of Biodiesel-diesel Blends (Test Method: UOP-413)
Detrioration of Vegetable oils during storage • Effect of aging on the physico-chemical characteristics of various non-edible vegetable oils were studied over a period of 30 months • Similar studies on Bio-diesel are in progress
Current R &D Programmes on Bio-diesel • Continuous Pilot Plant testing of Heterogeneous Trans-esterification Process • Studies to evaluate various vegetable oils for bio-diesel production • Performance evaluation of Bio-diesel-Diesel blends in engines and field trials on Indigo cars • Effect of bio-diesel on spray characteristics in diesel engines using CFD. • Development of additives for Bio-diesel-Diesel blends
Status of Technology • Currently IIP is operating batch pilot plants (5-20 lit/ batch) producing biodiesel using base catalyst. • Heterogeneous catalyst is being tested in continuous pilot plant. • Engine testing of biodiesel and field trials on diesel car is in progress. • Developed Sulfur free Multifunctional additives (MFA)for diesel and bio-diesel Diesel blends.