Ashish Shukla

Microwave Assisted Alkali Pretreatment of Rice Straw for Enhancing Enzymatic Digestibility

Rapid industrialization, increasing energy demand, and climate change are the conditions that forced the researchers to develop a clean, efficient, renewable, and sustainable source of energy which has a potential to replace fossil fuels. Ethanol is one of the attractive and suitable renewable energy resources. In present study, effectiveness of microwave pretreatment in combination with sodium hydroxide (NaOH) for increasing enzymatic hydrolysis of rice straw has been investigated and under optimum conditions obtained a maximum reducing sugar (1334.79 µg/mL) through microwave assisted NaOH pretreatment. Chemical composition analysis and scanning electron microscope (SEM) images showed that the removal of lignin, hemicellulose, and silicon content is more in microwave assisted NaOH pretreatment than the blank sample. X-ray diffraction (XRD) analysis revealed that the crystallinity index of rice straw treated with microwave assisted alkali (54.55%) is significantly high as compared to the blank (49.07%). Hence, the present study proves that microwave assisted alkali pretreatment can effectively enhance enzymatic digestibility of rice straw and it is feasible to convert rice straw for bioethanol production.

Achieving Energy Sustainability Through Green Building Approach

There are three urgencies in the UK climate and energy policies: (i) reducing greenhouse gas emissions, specifically CO2 by 80 %, by 2050, (ii) decreasing fossil fuel consumption especially built environment sector and (iii) reducing dependence on imported energy. Buildings account for 40 % of the total non-transport energy consumption both in UK and EU; therefore, reduction of energy consumption in the built environment will make a significant contribution in meeting these targets. On average, UK residents spend between 2.7 and 8.4 % on gas and electricity bills. Water bills also account for 0.5–3 % of their income. These scenarios make it important to consider green building design and reduce the social, environmental and economic impacts building are creating on us. Sustainability through green building design should encompass “cradle-to-grave analysis”. Building Research Establishment Environmental Assessment Methodology (BREEAM) is the world’s foremost environmental assessment method and rating system for buildings. BREEAM was launched in 1990 and sets the standard best practice in sustainable building design, construction and operation. The assessment uses measures of performance against established benchmarks. This chapter will highlight interesting features of achieving sustainable development through green building design.

Exergy Analysis of Solar Dryers

In order to find out the energy interactions and thermodynamic behaviour of drying air throughout a drying chamber, the energy and exergy analysis of the drying process needs to be informed. Exergy of a solar dryer is the maximum useful work possible during a drying process that brings the dryer into equilibrium with a heat reservoir. The exergy method can help further in maximizing efficient energy resource use because it is applied at component level and enables to determine losses for their magnitude at the point of origin. By using exergy method, it is possible to correct existing inefficiencies at its sources and design more efficient thermal system, and in the current case, it is solar dryer. Increased efficiency can often contribute in an environmentally acceptable way by the direct reduction of irreversibility that might otherwise have occurred.

Feasibility study on merging biogas into the natural gas pipe-network in China

Biogas is one of the options to improve the current serious energy and environment situation in China. However, biogas application is limited in China due to instabilities in quantity and quality of biomass. These instabilities are largely influenced by the local environment and climate. Merging non-upgraded biogas into the natural gas (NG) distributing system can (i) increase utilisation, (ii) reduce carbon intensity of gas pipe network and (iii) promote renewable energy usages. However, merging biogas into the gas pipe network comes with lots of challenges. This paper investigates the approaches of merging biogas into the NG distributing system. The interchangeabilities between the mixed bionatural gas and the Chinas 12T standard gas are evaluated based on several indices. This study results indicate that the maximal mixing volume ratio of non-upgraded biogas to the typical piped natural gas is 14.7% when the Wobbe number and combustion potential are used as determining indices.

Techno-Economic Analysis of an Earth-Air Heat Exchanger for Cooling and Heating of a Building

In this communication a quasi-steady state mathematical model is developed to predict the air temperature at the outlet of an earth-air heat exchanger and seasonal heating and cooling potential, associated with the use of the exchanger. Seasonal values of heating and cooling potential are estimated theoretically and validated by experiments in two distinct seasons, i.e. winter and summer, corresponding to composite climate of New Delhi (28° 35′ N, 77° 12′ E) India. It is observed that there is significant saving of energy and money by reducing cooling and heating loads on air-conditioners, if earth air heat exchanger is used. There is fair agreement between theoretical values and experimentally observed values of the seasonal values of heating and cooling potentials for each season (i.e. winter and summer).Copyright