Vol. 3 Issue 3 Jul.-Sep. 2012

S. Chongkhong*, B. Lolharat and P. Chetpattananondh

Abstract: Fresh jackfruit seeds consist of about 36% carbohydrates, molecules which can be easily converted to ethanol. Ethanol fermentation conditions of jackfruit seeds using microorganisms from rice cake starter were optimized by the response surface methodology (RSM). The central composite design (CCD) was used to investigate optimum parameter levels in ethanol production (an anaerobic process), viz. temperature, pH and time. The optimum fermentation conditions were a temperature of 32.2°C, pH of 5.2 and time of 124.5 h. In this case, the highest amount of ethanol obtained was 11.5%v.

Keywords: Ethanol, Jackfruit seed, Response surface methodology (RSM), Rice cake starter.

I. Khan*, H. Chowdhury, F. Alam, Q. Alam and S. Afrin

Abstract: Most scientific studies report that the increasing concentration of greenhouse gases in the atmosphere is causing global climate change. Human induced emissions of carbon dioxide and other greenhouse gases, as well as deforestation and land-use change are the primary causes of increasing greenhouse gas emissions. Climate change is believed to be responsible for frequent and intense natural disasters, and the rise of sea level and its salinity. People from low lying countries are being affected most. The effects of climate change are numerous. Apart from social, environmental and demographical impacts, global climate change also affects power generation capacity. The main aim of this study is to identify the impact of climate change on existing power plants, assessing how those plants might be affected depending on current geographic locations across the country. The study used Bangladesh as a case study as the country is extremely vulnerable to climate change due to much it being not much above sea level and its large population size. The study identified several parameters affected by global climate change and showed how each parameter can influence the power generation capacities of existing as well as future power plants.

Keywords: Global climate change, impact on power plant, infrastructure, plant site, salinity, sea level rise.

C. Tenthani*, A. Madhlopa and C.Z. Kimambo

Abstract: According to the 2010 Malawi Demographic and Health Survey (MDHS), about 65% of households in Malawi do not have access to treated water. Distillation is one technique used for treating water. Many distillation methods are available but they are either energy intensive or contribute to environmental degradation due to their nature. However, solar energy can be used as an alternative source of energy for water distillation. There are many designs of solar distillation systems but the most-widely used one is the conventional still. Internal surfaces of the walls of the conventional solar still (CSS) are commonly painted black to avert condensation of water vapor on the walls. However, the CSS suffers from low production of distilled water and there is, therefore, a need to improve its performance. In this study, two conventional stills were designed with an identical geometry but the internal surfaces of their walls were painted white. These solar stills were tested outdoors under the same meteorological conditions at the Malawi Polytechnic (15° 42' S, 35°02' E). Distillate output was measured during experimentation. It was found that the average daily distillate outputs were 2.55 kgm-2 and 2.38 kgm-2 for the experimental still and CSS respectively. In addition, the efficiency of the experimental solar still was 6.8% more than that of the CSS. It can therefore be concluded that painting the internal surfaces of the walls of the still white improves the distillate output of the still.

Keywords: Basin still, enhancement, experimental performance, passive solar.

J.A. Engel-Cox*, N.L. Nair and J.L. Ford

Abstract: Solar technology policy, development, and deployment require information related to meteorology and solar radiation to optimize technology selection and performance. As a tropical country, Malaysia has significant solar resources but a very limited radiation monitoring network. Meteorological data are available in more locations, but published analyses of these data are also limited. This paper presents an analysis of recent meteorological and radiation data in Malaysia as relevant to understanding solar technology performance. To compare differences between locations, yearly daily means of key meteorological parameters, global solar radiation (total radiation on the ground), and particulate air pollution were derived for 3-12 years, depending on the data availability. Annual mean global solar radiation values range from 3.73 to 5.11 kWh/(m2d) in the eight cities with monitors. The analysis also used neural network techniques to evaluate the potential for using the key variables of temperature, humidity, wind speed, rainfall, cloud cover, latitude, longitude, and particle pollution to estimate global solar radiation at various locations and seasons. Prediction on a monthly basis indicated a slight under-prediction of the model during the rainy season and a slight over-prediction during the dryer months, confirming that global solar radiation values depended strongly on rainfall.

Keywords: Malaysia, meteorology, solar radiation.

P. Sugumaran, V. Priya Susan, P. Ravichandran and S. Seshadri*

Abstract: Activated carbon was produced from banana empty fruit bunch (BEFB) and Delonix regia fruit pod (DRFP) through single step chemical activation process. As both the lignocellulosic wastes showed maximum weight loss at temperatures lower than 500°C, they were carbonized at 450°C (BEFP) and 400°C (DRFP) respectively after impregnating with H3PO4 and KOH. Highest yield of 41.09% was recorded in DRFP treated with H3PO4 followed by other treatments. The KOH treated DRFP recorded maximum bulk density of 0.46 g/ml followed by H3PO4 treated DRFP. The BEFP carbons displayed lower attrition values than DRFP carbons. While the H3PO4 treated DRFP carbon sample showed higher surface area, the untreated DRFP registered higher pore volume. However BET surface area was comparatively low in both the substrates. FT-IR analysis of H3PO4, KOH and untreated carbon sample, though did not show much difference in surface functional groups, showed shifts in bands and changes in wave numbers and absorbance between the untreated and treated samples indicating chemical transformations during pyrolysis. While highest iodine removal was observed in KOH treated BEFP and DRFP samples, methylene blue reduction was high in H3PO4, KOH and untreated BEFP carbon samples.

Keywords: Activated carbon, ligno-cellulose, banana empty fruit bunch, Delonix regia fruit pod, BET, iodine adsorption, methylene blue reduction.

S. Nairum and S. Towprayoon*

Abstract: This study was conducted to estimate methane emissions from domestic wastewater handling in Thailand during 1990-2008 by comparing the revised 1996 IPCC guidelines with the 2006 IPCC guidelines using results from activity data, assumptions and major parameters. The results using the revised 1996 IPCC guidelines showed that the methane emissions from domestic wastewater handling were higher than when using 2006 IPCC guidelines by about 1.49-1.64 times. These were due to the different parameters used and their assumptions including the fraction of population income group and the degree of utilization of treatment or discharge for each income group used in the 2006 IPCC guidelines. The differences in this study are due to the assumption of data of income fraction which is based on gross provincial product (GPP). Methane emissions from this study were higher than estimates reported elsewhere. The results were due to different BOD loads and different assumptions of urban and rural populations.

Keyword: methane, domestic wastewater, IPCC guidelines.