Dheeraj Rathore

Key issues in estimating energy and greenhouse gas savings of biofuels: challenges and perspectives

The increasing demand for biofuels has encouraged the researchers and policy makers worldwide to find sustainable biofuel production systems in accordance with the regional conditions and needs. The sustainability of a biofuel production system includes energy and greenhouse gas (GHG) saving along with environmental and social acceptability. Life cycle assessment (LCA) is an internationally recognized tool for determining the sustainability of biofuels. LCA includes goal and scope, life cycle inventory, life cycle impact assessment, and interpretation as major steps. LCA results vary significantly, if there are any variations in performing these steps. For instance, biofuel producing feedstocks have different environmental values that lead to different GHG emission savings and energy balances. Similarly, land-use and land-use changes may overestimate biofuel sustainability. This study aims to examine various biofuel production systems for their GHG savings and energy balances, relative to conventional fossil fuels with an ambition to address the challenges and to offer future directions for LCA based biofuel studies. Environmental and social acceptability of biofuel production is the key factor in developing biofuel support policies. Higher GHG emission saving and energy balance of biofuel can be achieved, if biomass yield is high, and ecologically sustainable biomass or non-food biomass is converted into biofuel and used efficiently.

Biohydrogen Production: Sustainability of Current Technology and Future Perspective

Concern over sustainability of fossil fuel use is raised due to depleting fuel resources and emitting greenhouse gases (GHGs) from it. Among many alternative energy sources, biofuels, natural gas, hydrogen, and synthesis gas (syngas) emerge as four strategically important sustainable energy sources. As hydrogen gas is renewable, it does not evolve GHGs, and releases large amount of energy in combustion of unit weight and hydrogen can also be easily converted into electricity by fuel cell. It could be a strong candidate for future alternate energy resource. Biological H 2 production delivers clean H 2 in sustainable manner with simple technology and more attractive potential than the current chemical production of H 2 . Although present industrial hydrogen production system is based on chemical processing units, research trend on biohydrogen promises a deafening potential of industrial biohydrogen production in the near future.

Growth Responses of Wheat (Triticum aestivum L. var. HD 2329) Exposed to Ambient Air Pollution under Varying Fertility Regimes

The problem of urban air pollution has attracted special attention in India due to a tremendous increase in the urban population; motor vehicles vis a vis the extent of energy utilization. Field studies were conducted on wheat crops (Triticum aestivum L. var. HD 2329) by keeping the pot-grown plants in similar edaphic conditions at nine different sites in Allahabad City to quantify the effects of ambient air pollution levels on selected growth and yield parameters. Air quality monitoring was done at all the sites for gaseous pollutants viz. SO2, NO2, and O3. Various growth parameters (plant height, biomass, leaf area, NPP, etc.) showed adverse effects at sites receiving higher pollution load. Reduction in test weight and harvest index was found to be directly correlated with the levels of pollutant concentrations. The study clearly showed the negative impact of air pollution on periurban agriculture.

Oxidative stress defence responses of wheat ( Triticum aestivum L.) and chilli ( Capsicum annum L.) cultivars grown under textile effluent fertilization

Oxidative stress is complex physiological phenomenon that accompanies virtually in all stresses including either the deficiency or the surplus of micronutrients in the soil. In response to reactive oxygen species (ROS) generation, plants use a range of mechanisms to minimize the toxicity and protect cell membranes from damage. There are known reports indicating that effluents from the textile industry can serve as a micronutrient supplier under otherwise limited conditions. However, the addition of these effluents may cause toxicity to plants due to the presence of some non-essential heavy metals and persistent compounds if supplied in excess. A mesocosm study was conducted with wheat (Triticum aestivum L) and chilli (Capsicum annum L) cultivars grown under textile effluent fertilization to evaluate the accumulation of malondialdehyde (MDA) and H2O2, and the enzymatic and non-enzymatic antioxidative defences developed against this stress. Our findings indicated that the accumulation of MDA and H2O2 were mainly stimulated in control plants (0% textile effluent) followed by 60% concentration of textile effluent fertilization. Plants counteract oxidative stress by increasing both enzymatic (Superoxide dismutase, SOD; catalase, CAT; peroxidase, POX; ascorbate peroxidase, APX; glutathione reductase, GR) and non-enzymatic (phenolic compounds, flavonoids and ascorbic acid) antioxidants significantly. The activities of major antioxidants were promoted by higher concentrations of textile effluents. In addition, low antioxidative defences against damage caused by oxidative stress to the controls were evident by yield loss and deteriorated product quality. Compared to the chilli cultivars, MDA and H2O2 were higher in wheat cultivars; at the same time activities of antioxidants were also higher in wheat cultivars. The results of this study showed that the application of textile effluents supplied plant nutrients which improved antioxidative defences by regulating the enzymatic and non-enzymatic antioxidative mechanisms while the nutrient deprived condition prevailed.

Biohydrogen: Global Trend and Future Perspective

Global utilisation of confined and traded hydrogen is projected to increase more than 300 billion cubic meters through 2018 with an annual growth rate of 3.5 %. The maximum share of growth through 2018 is likely to occur in China though the world’s largest hydrogen consumption will continue with the USA. This view is supported by the published research in the recent past. Published articles on biohydrogen research are highest from China followed by the USA and India. Published data on biohydrogen also suggested that biohydrogen production from the Asian countries is mainly focusing on dark fermentation, whilst the European countries are focusing on dark and photofermentation. So far, the current biohydrogen production system is appropriate for decentralised small-scale systems, integrated with waste from agriculture and industries or from waste-processing facilities, using reactors operating with mixed microflora (aerobic, anaerobic, thermophilic, purple non-sulphur photosynthetic bacteria) or pure cultures enriched from natural sources. Seed inocula for biohydrogen production have been obtained from heat sludge, compost, waste water, food waste, etc. With many social, economic and environmental benefits, hydrogen energy is considered as a future of the sustainable energy source.

Ozone risk assessment of castor (Ricinus communis L.) cultivars using open top chamber and ethylenediurea (EDU)

Castor bean (Ricinus communis L.) an important non-edible oilseed crop, is a prominent feed stock towards the generation of renewable materials for industrial production which has multiple applications ranging from cosmetics to biofuels industry. India accounts for 76% of the total world production of castor oil seed. However, major concern for developing countries like India where expanding economy led to rapid increases in gases like NOx, CO and VOCs photochemically form ozone. Ozone is strong oxidant that damages agriculture, ecosystems, and materials with considerable reduction in crop yields and crop quality. One way to reduce ozone induced loss is to focus on the adapting crops to ozone exposure by selecting cultivars with demonstrated ozone resistance. An experiment was conducted for ozone risk assessment of castor cultivars to select cultivar with demonstrated resistance against ozone pollution. This study comprise an open top chamber experiment with three treatments viz. (i) control (ambient ozone concentration), (ii) enhanced ozone (average 75 ppb for 4 h daily throughout the growing season), and (iii) EDU application. Results suggested that the ozone pollution substantially affected growth and physiology of castor cultivars. Crop biomass and yield was also negatively influenced by ozone pollution. Developed defence provided strength to withstand against ozone pollution to the experimental crop cultivars. However, developed defence is cultivar specific and positively correlated with the resistance against ozone pollution. Study concluded that the damage to ozone is directly dependent on the antioxidative potential of plant species. However, ozone adaptability is based on the genetic makeup of the cultivar and yield related loss to ozone can be minimizing by selecting ozone tolerant variety as seen in cultivar Nidhi-999.

Biohydrogen: Next Generation Fuel

Concern over sustainability of fossil fuel use is raised due to depleting fuel resources and emitting greenhouse gases (GHGs) from it. Among many alternative energy sources, biofuels, natural gas, hydrogen, and synthesis gas (syngas) emerge as four strategically important sustainable energy sources. As hydrogen gas is renewable, it does not evolve GHGs, and releases large amount of energy in combustion of unit weight and hydrogen can also be easily converted into electricity by fuel cell. It could be a strong candidate for future alternate energy resource. Biological H2 production delivers clean H2 in sustainable manner with simple technology and more attractive potential than the current chemical production of H2. Although present industrial hydrogen production system is based on chemical processing units, research trend on biohydrogen promises a deafening potential of industrial biohydrogen production in the near future.