Venkateswarlu Chintala

Reduction of GHGs Emissions in a Biodiesel Fueled Diesel Engine Using Hydrogen

The experimental tests were conducted on a 7.4 kW rated diesel engine fueled with biodiesel-diesel blend (B20) for quantitative evaluation of greenhouse gases (GHGs) emissions. The result indicates that carbon dioxide (CO2) emission did not change significantly with B20 whereas methane (CH4) and nitrous oxide (N2O) emissions with B20 decreased marginally as compared to base diesel. In order to reduce further these emissions, the effect of hydrogen (H2: 20% energy share) on GHGs emissions in the biodiesel (B20) fueled diesel engine under dual fuel mode is assessed. CO2 emission decreased drastically with H2 due to higher thermal efficiency and lesser carbon content of the fuels than base diesel and B20 whereas CH4 and N2O emissions decreased significantly due to high temperature combustion. At rated load, CO2, CH4 and N2O emissions of the engine decreased about 46%, 22% and 27% respectively with biodiesel (B20)-H2 (20% energy share) under dual fuel mode as compared to conventional base B20 mode. A conclusion is clearly emerged from this study that the formation of CH4 and N2O emissions are dependent on in-cylinder pressure and temperature. Hydrogen addition to the diesel engine is an effective solution to reduce CO2 along with CH4 and N2O emissions.Copyright

Performance and emission characteristics of a diesel engine using complementary blending of castor and karanja biodiesel

Abstract The performance and emissions of blends of karanja and castor biodiesel with conventional diesel in an unmodified single-cylinder DI diesel engine was studied. Different combination of biodiesel and diesel (castor 5% + karanja 5% + diesel 90%, castor 5% + karanja 10% + diesel 85%, castor 10% + karanja 5% + diesel 85%, castor 5% + karanja 15% + diesel 80%, castor 10% + karanja 10% + diesel 80% and castor 15% + karanja 5% + diesel 80%) were studied under varying load from 0 to 100%. The results revealed that BTE slightly decreased while BSFC increased with increasing biodiesel concentration in fuel blends. Unburned hydrocarbon (HC), carbon monoxide (CO), carbon dioxide (CO2), nitrogen oxides (NOx) and smoke reduced with increasing biodiesel content in fuel blends. An increasing concentration of castor biodiesel resulted in higher emissions. The blend containing castor 5% + karanja 10% + diesel 85% was found most suitable for a DI diesel engine in the context of performance and emission.

Thermochemical pyrolysis of biomass using solar energy for efficient biofuel production: a review

ABSTRACT The increasing energy demand of a rapidly growing population has rekindled the interest of humankind in the use of biomass as a source of energy. The main factors behind this resurgent interest in biofuels are the fast-depleting fossil fuel reservoirs and concerns regarding climate change. The proper choice of technology for conversion of biomass into clean-burning fuel is essential for sustained use of biomass as a source of energy. Various thermo-chemical conversion processes such as combustion, hydrogenation, liquefaction, gasification and pyrolysis have been utilized to extract various energy products from biomass. Even though pyrolysis, of all the thermo-chemical processes, is still in a preliminary stage of development, it has received special attention in our present energy scenario as it can convert biomass into various liquid, solid and gaseous products. The use of solar energy provides a renewable source for pyrolysis, which gives it an edge over use of thermal energy. This paper presents a comprehensive review of the various pyrolysis techniques and their comparative advantages and disadvantages in terms of their environmental impacts. The advantages of using solar thermal power over other pyrolysis methods are also covered in detail.