Radhakrishnan Srinivasan

Performance and emissions of a spark-ignited engine driven generator on biomass based syngas

The emergence of biomass based energy warrants the evaluation of syngas from biomass gasification as a fuel for personal power systems. The objectives of this study were to determine the performance and exhaust emissions of a commercial 5.5 kW generator modified for operation with 100% syngas at different syngas flows and to compare the results with those obtained for gasoline operation at same electrical power. The maximum electrical power output for syngas operation was 1392 W and that for gasoline operation was 2451 W. However, the overall efficiency of the generator at maximum electrical power output for both the fuels were found to be the same. The concentrations of CO and NO(x) in the generator exhaust were lower for the syngas operation, respectively by 30-96% and 54-84% compared to the gasoline operation. However, the concentrations of CO(2) in the generator exhaust were significantly higher by 33-167% for the syngas operation.

Pilot scale fiber separation from distillers dried grains with solubles (DDGS) using sieving and air classification

Distillers dried grains with solubles (DDGS), the coproduct of fuel ethanol production from cereal grains like corn, is mainly used as cattle feed and is used at low inclusion levels in poultry and swine diets because of high fiber content. Elusieve process, the combination of sieving and air classification (elutriation), was developed in laboratory scale to separate fiber from DDGS to result in a low fiber product which would be more suitable for poultry and swine. In this pilot scale study, DDGS was sieved at a rate of 0.25 kg/s (1 ton/h) into four sieve fractions using a sifter and the three largest sieve fractions were air classified using aspirators to separate fiber on a continuous basis. Results were similar to laboratory scale. Nearly 12.4% by weight of DDGS was separated as Fiber product and resulted in two high protein products that had low fiber contents. Payback period for the Elusieve process in an existing dry grind plant processing corn at the rate of 2030 metric tonnes/day (80,000 bushels/day) would be 1.1 yr.

Producing Hydrogen through Water Gas Shift Reaction over Nickel Catalysts

Water gas shift (WGS) reaction has an important role in the hydrogen production and related processes such as methanol synthesis, ammonia synthesis, and fuel cell applications. The paper presents the recent advances of WGS process using supported nickel catalysts. The effects of different supports, nickel loading, and reaction temperatures on the catalyst activity and selectivity are discussed. Ceria promoted nickel catalyst supported on powder alumina (Ni/CeO2-Al2O3) demonstrated the best performance. The catalyst was stable at high temperature (450oC) but deactivated at low temperature (250oC). Increasing nickel loading resulted in a better performing Ni/CeO2-Al2O3 catalyst. The activity of 4%Ni/CeO2-Al2O3 was 49% with H2 yield and H2 selectivity were 36% and 61%, respectively.