IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Department Of Chemical Engineering

Current Science

Culture, science and music in the theatre of education

We examined LEDs as a cheap and test lamp source to simulate monochromatic laser radiation to help us cost out optics while evaluating materials for renewable fuels. The light source spectrum was recorded using a fiber optic spectrophotometer and a calibrated silicon photodiode was used to determine the intensity. Photon flux from the LEDs was recorded using actinometry. We chose CdS and Fe 3O 4 as photocatalysts. The as-prepared and annealed samples were characterised using X-Ray Diffraction, UV-Visible spectroscopy, UV-Visible Diffuse reflectance spectroscopy, Fourier Transform Infra-red spectroscopy, Attenuated Total Reluctance-FTIR spectroscopy, Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). CdS and Fe 3O 4 were evaluated for hydrogen evolution using DI water, sacrificial agents and an electron donor (methyl viologen) using three light sources (LEDs, sunlight and mercury vapour lamp). Products were collected by an inverted burette (Generation 1), balloons with a B-14 adapter (Generation2) and septum cells (Generation3). Developing an analytical technique to quantify products continues to remain a challenge. © 2011 Materials Research Society.

GENERAL

Materials Research Society Symposium Proceedings

Costing out light source and product collection during evaluation of materials for renewable fuels

The synthesis and analysis of inorganic material combinatorial libraries by a directed-sorting, split−pool bead method was demonstrated. Directed-sorting, split−pool, metal-loaded libraries were synthesized by adsorbing metal salts (H2PtCl6, SnCl2, CuCl2, and NiCl2) and metal standards (Pt, Cu, Ni in HCl) onto 2-mg porous γ-alumina beads in 96- or 384-well plates. A matrix algorithm for the synthesis of bead libraries treated each bead as a member of a row or column of a given matrix. Computer simulations and manual tracking of the sorting process were used to assess library diversity. The bead compositions were analyzed by energy-dispersive X-ray spectroscopy, X-ray fluorescence spectroscopy, electron probe microanalysis, inductively coupled plasma atomic emission spectroscopy, and inductively coupled plasma mass spectroscopy. The metal-loaded beads were analyzed by laser-activated membrane introduction mass spectroscopy (LAMIMS) for catalytic activity using methylcyclohexane dehydrogenation to toluene as a probe reaction. The catalytic activity of individual beads that showed minimal (∼20% of that of Pt on alumina) to high conversion could be determined semiquantitatively by LAMIMS. This method, therefore, provides an alternative to screening using microreactors for reactors that employ catalysts in the form of beads. The directed-sorting method offers the potential for synthesis of focused libraries of inorganic materials through relatively simple benchtop split−pool chemistry.

World University root node

Directed-Sorting Method for Synthesis of Bead-Based Combinatorial Libraries of Heterogeneous Catalysts

The directed sorting approach towards the synthesis of inorganic bead libraries building, based on matrix methods and adsorption in well plates, was discussed. The main advantages of the system are its simplicity, ease of preparation and low cost. The use of a multi-pipettor and corresponding analysis eliminates the need of commercial plotters routinely used in combinatorial chemistry which results in large cost savings. This technique highlights the importance of order of addition in optimization of catalytic activity or other catalytic figures of merit.

American Chemical Society, Division of Petroleum Chemistry, Preprints

Directed sorting method for synthesis of supported metal catalysts for methylcyclohexane dehydrogenation

Microbial fuel cells (MFCs) have been used to produce electricity from different compounds, including acetate, lactate, and glucose. We demonstrate here that it is also possible to produce electricity in a MFC from domestic wastewater, while at the same time accomplishing biological wastewater treatment (removal of chemical oxygen demand; COD). Tests were conducted using a single chamber microbial fuel cell (SCMFC) containing eight graphite electrodes (anodes) and a single air cathode. The system was operated under continuous flow conditions with primary clarifier effluent obtained from a local wastewater treatment plant. The prototype SCMFC reactor generated electrical power (maximum of 26 mW m-2) while removing up to 80% of the COD of the wastewater. Power output was proportional to the hydraulic retention time over a range of 3−33 h and to the influent wastewater strength over a range of 50−220 mg/L of COD. Current generation was controlled primarily by the efficiency of the cathode. Optimal cathode performance was obtained by allowing passive air flow rather than forced air flow (4.5−5.5 L/min). The Coulombic efficiency of the system, based on COD removal and current generation, was &lt;12% indicating a substantial fraction of the organic matter was lost without current generation. Bioreactors based on power generation in MFCs may represent a completely new approach to wastewater treatment. If power generation in these systems can be increased, MFC technology may provide a new method to offset wastewater treatment plant operating costs, making advanced wastewater treatment more affordable for both developing and industrialized nations.

Production of Electricity during Wastewater Treatment Using a Single Chamber Microbial Fuel Cell

Factors that could affect microbial fuel cells (MFC) operation: the type of proton exchange and the effect of oxygen contamination on MFC operation were examined. A MFC containing membrane was inoculated with G. metallireducens using growth medium containing ferric citrate and bacteria, but power generation was initially very low (0.1 mw/sq m). When L-cysteine was added to the anode chamber at 334 hr with fresh medium, the power output increased to 7.8 mw/sq m within 451 hr, generating power that was an order of magnitude larger than that achieved with the salt bridge MFC using the same bacterium and L-cysteine. The increase in power generation following the addition of L-cysteine confirmed that dissolved oxygen was contributing to the original low level of power generation. Power generation was further increased by adding additional acetate at a final concentration of 20 mM at 900 hr. In the salt bridge MFC, only a small potential (< 5 mv) developed across the MFC circuit over the first 100 hr of operation. Low power generation in the salt bridge MFC was primarily due to differences in internal resistance between the two systems. The internal resistance of the salt bridge MFC was 14 times higher than that obtained from the Nafion membrane MFC. This is an abstract of a paper presented at the 228th ACS National Meeting (Philadelphia, PA 8/22-26/2004).

ACS, Division of Environmental Chemistry - Preprints of Extended Abstracts

Electricity production in salt bridge and membrane microbial fuel cells

The paper reviews catalytic naphtha reforming, a process that has completed 50 y of existence and has improved the quality of human life globally. Also examines in detail are the historical background of reforming, reaction chemistry, reaction thermodynamics, process details, process variables, commercial processes, and future outlook. Recent environmental regulations have completely re-drawn the objectives of reforming and have even questioned its relevance. Attempts are also made to explain, in brief, the new challenges faced by reforming.

Journal of Scientific and Industrial Research

Catalytic naphtha reforming: Revisiting its importance in the modern refinery

We have synthesized nanoporous carbon membranes that have monodisperse pores of 4-5 Å. These membranes have excellent size and shape selectivity that makes them an ideal candidate for use as separators in fuel cells. The selectivity of these membranes to gases such as N2, Q2 and water gas [carbon monoxide and hydrogen] were measured using a permeation testing unit. These membranes were then tested as separators in fuel cells.

Department Of Civil Engineering

Materials Research Society Symposium - Proceedings

Using nanoporous carbon membranes in fuel cells

The synthesis and analysis of inorganic material combinatorial libraries by the split-pool bead method were demonstrated at the proof-of-concept level. Millimeter-size spherical beads of porous γ-alumina, a commonly used support material for heterogeneous catalysts, were modified with Al13O4(OH)24(H2O)127+ cations in order to promote irreversible adsorption of the anionic fluorescent dyes Cascade Blue, Lucifer Yellow, and Sulforhodamine 101. The compositions of individual beads were easily determined through three split-pool cycles using a conventional fluorescence plate reader. Small split-pool material libraries were made by adsorbing noble metal salts (H2PtCl6, H2IrCl6, and RhCl3) into the beads. Analysis of these beads by micro-X-ray fluorescence showed that quantitative adsorption of metal salts without cross-contamination of beads could be achieved at levels (0.3 wt % metal loading) relevant to heterogeneous catalysis. The method offers the potential for synthesis of rather large libraries of inorganic materials through relatively simple benchtop split-pool chemistry.