Madhukar O. Garg

Hydroprocessing of jatropha oil and its mixtures with gas oil

Hydroprocessing catalysts, sulfided Ni–W/SiO2–Al2O3, Co–Mo/Al2O3 and Ni–Mo/Al2O3 have been developed, and their performances in hydroprocessing of jatropha oil and its mixtures with refinery gas oil compared in terms of, detailed product distribution in order to optimize the catalyst and conditions that can give maximum yield of desired transportation fuel such as diesel or kerosene (jet). C15–C18 hydrocarbon yield (diesel range) is highest (97.9%) over Ni–Mo catalyst, while it is 80.8% over Ni–W catalyst and surprisingly low (49.2%) over Co–Mo catalyst. Jatropha oil with high as well as low free fatty acid (FFA) contents could be hydroprocessed with little observable effect on reactor metallurgy. The isomers to n-paraffins (i/n) ratio is very low and different for the three types of catalysts- nearly 22–36 times higher for the hydrocracking (Ni–W) catalyst than that for the hydrotreating (Ni–Mo) catalyst. The hydrodeoxygenation pathway for oxygen removal from triglyceride is favored over the fresh Ni–Mo and Co–Mo catalysts, while decarboxylation/decarbonylation pathway is favored over the Ni–W catalyst. But, resulfidation of used Ni–Mo catalyst results in decarboxylation/decarbonylation route being slightly more favored. The yield of diesel range (250–380 °C) product during co-processing varied between 88–92% for the Ni–Mo catalyst. Hydrodesulfurization of gas oil is better during co-processing with jatropha oil. The activation energy for overall S-removal is much lower than that for overall O-removal. Densities of the products were also observed to meet the required specification.

A comprehensive life cycle assessment (LCA) of Jatropha biodiesel production in India

A life cycle approach was adopted for energy, green house gas (GHG) emissions and renewability assessment for production of 1ton of Jatropha biodiesel. Allocation and displacement approaches were applied for life cycle inventory, process energy and process GHG emission attribution to co-products. The results of process energy and GHG emission analyses revealed that the amount of process energy consumption and GHG emission in the individual stages of the life cycle assessment (LCA) were a strong function of co-product handling and irrigation. The GHG emission reduction with respect to petroleum diesel for generating 1GJ energy varied from 40% to 107% and NER values from 1.4 to 8.0 depending upon the methodology used for energy and emission distribution between product and co-products as well as irrigation applied. However, GHG emission reduction values of 54 and 40 and NER (net energy ratio) values of 1.7 and 1.4 for irrigated and rain-fed scenarios, respectively indicate the eco-friendly nature and renewability of biodiesel even in the worst scenario where total life cycle inventory (LCI), process energy and GHG emission were allocated to biodiesel only.

THE REMOVAL OF FURFURAL FROM WATER BY ADSORPTION WITH POLYMERIC RESINS

The removal of furfural from water by adsorption on a polymeric resin XAD-4 was studied. Equilibrium isotherm measurements were made and column dynamic data collected under various sets of operating conditions. The axial-dispersed plug-flow model was used to simulate the experimental data. The linear driving force parameters required in these simulations were determined independently of the column measurements, providing a more versatile simulation model. The model predicts the breakthrough curves with a fair degree of accuracy.

Carbon Di-Oxide Removal with Mesoporous Adsorbents in a Single Column Pressure Swing Adsorber

Abstract A five-step PSA cycle was studied for CO2 separation from CO2-N2 gas mixture in a single column at elevated temperatures using Poly-ethyleneimine (PEI) impregnated mesoporous silica SBA-15 as adsorbent. The PSA cycle study included a strong adsorptive rinse step in which the strongly adsorbed component, i.e., CO2 was used for rinsing the adsorbent bed in order to increase the purity of CO2 product. The study indicates that the adsorbent is regenerable under typical PSA conditions. The productivity of the adsorbent studied for CO2 separation was found to be comparable with commercial zeolite adsorbents as reported in literature.

Catalytic cracking of jatropha-derived fast pyrolysis oils with VGO and their NMR characterization

Lignocellulosic biomass-derived fast pyrolysis oils are potential second-generation bio-fuels towards the reduction of greenhouse gas (GHG) emissions and carbon foot prints. This study pertains to co-process the Jatropha-derived heavy or tar fraction of fast pyrolysis oil (FPO) with vacuum gas oil (VGO) and hydrodeoxygenated fast pyrolysis oil (HDO) with VGO in a standard refinery fluid catalytic cracking (FCC) unit. The crude fast pyrolysis oil from Jatropha curcas is produced at 530 °C and atmospheric pressure using a bubbling fluidized bed pyrolyzer. The heavy fraction of FPO is hydrodeoxygenated over Pd/Al2O3 catalyst into HDO in an autoclave reactor at 300 °C and pressure of 80 bar. Further, HDO is co-processed with petroleum-derived VGO in an advanced cracking evaluation (ACE-R) unit to convert it into refinery FCC product slate hydrocarbons at a blending ratio of 5 : 95. FPO and HDO are characterized using 31P NMR, whereas FCC distillates, which are obtained on the co-processing of VGO with fast pyrolysis oil and HDO, are characterized using 1H and 13C NMR spectroscopy techniques. The 31P NMR analysis of crude FPO and HDO indicated that hydroxyl, carboxylic and methoxy groups are reduced during the hydrodeoxygenation of FPO. The experimental results at the iso-conversion level on the co-processing of HDO with VGO indicated a higher yield of liquefied petroleum gases (LPG), while lower yields of gasoline and LCO have been observed as compared to FPO co-processing with VGO and co-processing of pure VGO. Furthermore, the results of co-processing of FPO with VGO indicated that the yields of gasoline and LCO increased from 29 to 35 wt% and 14.8 to 20.4 wt%, respectively, whereas the yields of dry gas and LPG decreased from 2.1 to 1.4 wt% and 38.8 to 23.7 wt%, respectively, for an increase in the blending ratio from 5% to 20%. Therefore, it can be concluded that the co-processing of HDO with VGO in a FCC unit would be feasible in order to achieve a higher yield of LPG.

A vapor phase adsorptive desulfurization process for producing ultra low sulphur diesel using NiY zeolite as a regenerable adsorbent

A NiY zeolite based vapor phase adsorptive desulfurization process has been described which can bring down sulphur concentration of a commercial BS IV grade (Euro IV equivalent) diesel from 50 ppm to a <5 ppm level. Compared to literature reports on fixed bed adsorptive desulfurization of diesel using zeolite adsorbents, the present process has the advantage of easy regenerability of the adsorbent with minimum temperature swing between adsorption and regeneration steps. Multi cycle stability of the desulfurization performance was also demonstrated.

Estimation of trace amounts of benzene in solvent-extracted vegetable oils and oil seed cakes

A new method is presented for the qualitative and quantitative estimation of trace amounts (up to 0.15 ppm) of benzene in crude as well as refined vegetable oils obtained by extraction with food grade hexane (FGH), and in the oil seed cakes left after extraction. The method involves the selection of two solvents; cyclohexanol, for thinning of viscous vegetable oil, and heptane, for azeotroping out trace benzene as a concentrate from the resulting mixture. Benzene is then estimated in the resulting azeotrope either by UV spectroscopy or by GC-MS subject to availability and cost effectiveness of the latter. Repeatability and reproducibility of the method is within 1-3% error. This method is suitable for estimating benzene in vegetable oils and oil seed cakes.

Characterization and Identification of Polycyclic Aromatic Hydrocarbons in Diesel Particulate Matter

Emission of toxic exhaust from diesel engines is one of the major problems associated with the use of petroleum fuels. Particulate matter emission is perceived as a major pollutant, detrimental to the human health and environment, and has led to considerable study. Vehicular emissions comprise toxic pollutants that include unburnt hydrocarbons, polycyclic aromatic hydrocarbons, dioxins, and others. In this study, experiments have been carried out with the objective of determining overall particulate matter chemical composition and size. Electron microscopic images of the emitted soot were studied for average particle size distribution. More than 50 percent of the particles were in the range of 25 to 35 nanometers. Approximately 7, 9, 16, and 5 percent of the measured particles were from 35 to 40, 40 to 45, 45 to 50, and 50 to 55 nanometers, respectively. Determined elements were Al, Ba, Ca, K, Mg, Ti, Zn, and Zr at concentrations of 727, 53, 1100, 701, 1145, 638, 177, and 800 micrograms per milliliter respectively. Fifteen polycyclic aromatic hydrocarbons were detected in the extracts of filters and their concentrations were estimated. This investigation allows the comparison of particulate matter from different fuels and their blends.

Zeolite catalysed light hydrocarbon conversions

Availability of light alkane containing feedstocks in petroleum industry demands the catalysts and conversion processes. Two zeolites, ZSM-5 and Mordenite were used for the preparation of a series of catalysts for the conversion of pure light hydrocarbons and industrial feedstocks. Cracking and aromatisation activity of the H-ZSM-5 catalysts varied with the catalyst properties and feed composition. The cracking and hydrogen transfer reactions are facilitated in the HZS catalyst and resulted in the formation of aromatics along with Liquefied Petroleum Gas (LPG). Pt/Mordenite-based catalyst could improve the isoparaffin composition in the industrial feedstocks, where along with n-paraffins, considerable amount of olefins, naphthenes and aromatics were also converted into iso-paraffins through hydrogenation, ring-opening and isomerisation reactions. Benzene in the feedstock was successfully converted and the product exhibited almost zero benzene at optimised reaction conditions.