download (pdf, 6MB) - SNV

More documents

Recommendations

Info

10.43 Substitution of Agricultural Residue as Fuel Because of the lack of easy access of other fuels as well as economic compulsions, some households in rural country like Nepal still are forced to use agricultural residues as fuel. However, the advent of biogas plants has succeeded in substituting this primitive fuel by more environment friendly biogas stoves. 10.4.4 Availability of Slurry Biogas replaces the dung cake which otherwise is being used as a fuel for cooking. This substitution is on the one hand is environmentally healthy. On the other hand, the digested slurry, which is produced in the process of biogas formation, can be used as excellent organic manure in the field, thus, increasing the crop yield. 10.4.5 Saving of Kerosene The decrease in kerosene consumption has a twofold benefits. Firstly, kerosene is comparatively a costly fuel and its reduction can result in a significant financial saving. Since kerosene is an import commodity, its reduction also contributes in reducing the foreign exchange out-flows. Secondly, kerosene is one of the high PIC emitting fuels; hence, its reduction also contributes towards decreasing the Greenhouse Commitment. 10.4.6 Economic Gains As biogas plant utilizes locally available raw materials, the gas obtained from it can be cheaper compared to using other traditional and commercial fuels. In case of Nepal, an economic analysis of the entire BSP I and II results in an estimated EIRR of 11 percent when only the benefits of fuelwood and kerosene savings are accounted for. If the benefits of saved labour are added, the EIRR rises to 15 percent. Adding the total value of the nutrients saved by the BSP increases the EIRR to 32 percent. Including the conservation estimates for the health benefits of smoke reduction (US$ 6.67 / household / year) increases the EIRR to 36 percent. Finally, adding the value of the reduced carbon provides an EIRR of 50 percent (Mendis and van Nes, 1999). 10.5 IMPLICATION ON ENVIRONMENT The world is presently witnessing an avalanche of new environmental issues entirely different from the ones of the past decades, both in physical extent and complexity. As the number of new environmental issues increased, so did their geographic extent and, reaching regional and often global proportions. The potential dangers of global warming and the ensuring climate change due to the accumulation of carbon dioxide in the atmosphere is one such adverse example of environmental transformation brought about by human society's interference. Once, all climate changes occurred naturally. However, the onset of the Industrial Revolution led to the beginning of altering of our environment and climate through changing agricultural and industrial practices. The ever increasing population explosion, fossil fuel burning, and deforestation has resulted in the alteration of the chemical composition of the atmosphere through the build-up of greenhouse gases -primarily carbon dioxide, CFCs, methane and nitrous oxide. The increased atmospheric concentration of these greenhouse gases has significantly raised the threat of global warming. Studies have indicated that the global mean surface temperatures have increased 0.5-1.0°F since the late 19th century. The 20th century's 10 warmest years all occurred in the last 15 years of the century 8 It has been calculated that a doubling of carbon dioxide concentration would lead to an increase in temperature ranging anywhere from 1.5°C to 4. 5°C (Kojima, 1998). Such observations and predictions have succeeded in projecting global warming as one of the most serious environmental problem facing the world today. There has been a real, but irregular, increase in global surface temperature since the late nineteenth century. Several other form of scientific evidence confirms the general belief that progressive warming is caused by increasing GHGs concentrations in the atmosphere (TERI, 1996). However, there is considerable uncertainty regarding the extent of temperature rise, scale, timing, regional distribution, and related issues. 8 http://www.epa.gov/globalwarming/ 81
A wide range of natural and human activities release GHGs into the atmosphere. Even though the net contribution from anthropogenic activities is relatively small as compared to the natural activities, it is enough to significantly modify the natural balance. Figure 10.1 shows that among the anthropogenic GHGs emission, CO2, is the largest contributor to the total increase in climate forcing, followed by CFCs, CH 4 and N 2 O (TERI, 1996). Figure 10.1: The Contribution from each of the Anthropogenic GHGs to the Change in Radiative Forcing from 1980-1990 Growing concern about the effects of climate change has led to increasing research, policy initiatives, and development of innovative programmes and projects around the world. One such mitigating measure is the substitution of biomass and fossil fuels with alternative energy sources with lower global warming commitment. Biogas is one such alternative, especially in the rural communities, which offer the opportunity of providing a renewable source of household energy with extremely low global warming commitment (Smith et. al. 2000). 10.6 CARBON EMISSION SAVED FROM THE SUBSTITUTION OF TRADITIONAL AND COMMERCIAL FUELS BY BIOGAS As a consequence of the substitution of traditional fuels such as fuelwood, crop residue and dung, and commercial fuels such as kerosene and LPG to some extent by the biogas plants has a great potential of reducing Carbon emission into the atmosphere. Such reduction when seen at the nationwide perspective can be very significant even though at the household level it might seem not so significant. A study carried out in India in the year 2000 very explicitly highlights the amount of carbon emission generated when burning various biomass and fossil fuels. The study clearly indicates how much Carbon emission is saved when biogas replaces these fuels (Smith et. al. 2000). 10.7 CARBON EMISSION SAVED FROM THE DECREASE IN USE OF FUELWOOD Because of their poor combustion conditions, the traditional stoves using fuelwood are thermally inefficient and thus divert a significant portion of the fuel carbon into products of incomplete combustion (PICs), which generally have a greater impact on climate than CO 2 . A study done by Smith et al (2000) indicates that a kilogram of wood burned in a traditional mud stove generates 418 gram Carbon (g-C) equivalent of Carbon emission 9 . 9 The figure is for Africa. 82
Page 2 and 3:
BIOGAS As Renewable Source of Energ
Page 4 and 5:
FOREWORD I have the pleasure to go
Page 6 and 7:
EDITORS NOTE Since its inception fr
Page 8 and 9:
IBS IEIA IOE INGO IQC IRR JBT KfW K
Page 10 and 11:
TABLE CONTENTS FOREWORD EDITOR'S NO
Page 12 and 13:
13.5 Long-term Government Policy 11
Page 14 and 15:
List of Tables Table 1.1 Table 1.2
Page 16 and 17:
Figure 5.6 Figure 5.7 Figure 5.8 Fi
Page 18 and 19:
CHAPTER I CHARACTERISTICS OF BIOGAS
Page 20 and 21:
Figure 1.1 clearly indicates that t
Page 22 and 23:
CHAPTER II DESIGN CONCEPT AND RELAT
Page 24 and 25:
Chinese model fixed dome biogas pla
Page 26 and 27:
2.2.4 Other Designs Figure 2.4: Dee
Page 28 and 29:
Anaerobic Filter: The anaerobic fil
Page 30 and 31:
■ Suitable foundation condition -
Page 32 and 33:
Solution: From Table 2.2: 1 cow yie
Page 34 and 35:
2.6.2 Volume Calculations for Chine
Page 36 and 37:
The resultant force is as follows:
Page 38 and 39:
CHAPTER III MICROBIAL ACTIVITIES IN
Page 40 and 41:
substances are solubilized into sim
Page 42 and 43:
3.4 FACTORS AFFECTING MICROBIAL ACT
Page 44 and 45:
CHAPTER IV VARIOUS USES OF BIOGAS A
Page 46 and 47:
Figure 4.5: Sketch of Ujeli Biogas
Page 48 and 49: The volume of water form the 5 HP p
Page 50 and 51: . Availability of Fertilizer Cattle
Page 52 and 53: d. Needs Match Sticks More matchsti
Page 54 and 55: In which Q = rate of heat loss, (en
Page 56 and 57: . Integration of Solar Energy Integ
Page 58 and 59: 5.4.1 Biogas Reactor at Lukla/Mosi
Page 60 and 61: Figure 5.8: The Flat View of the Pi
Page 62 and 63: CHAPTER VI BIOGAS IN RELATION TO OT
Page 64 and 65: Table 6.1: Impact of Biogas on vari
Page 66 and 67: Chinese experience shows that if th
Page 68 and 69: 7.2 NITROGEN CYCLE Bio-slurry is ri
Page 70 and 71: 7.4.2 Nutrient Content of Bio-slurr
Page 72 and 73: To avoid the loss of ammonia (NH 4
Page 74 and 75: Experiment with Bio-slurry on Maize
Page 76 and 77: stated that cucumber yielded double
Page 78 and 79: 7.8.5 Philippines In the Philippine
Page 80 and 81: Cross Section—B-B Figure 7.4: Mod
Page 82 and 83: CHAPTER VIII BIOGAS PRODUCTION FROM
Page 84 and 85: ■ ■ ■ Excreta available /day
Page 86 and 87: It is to be noted that the settling
Page 88 and 89: 8.43 Operation of Biodigester After
Page 90 and 91: 9.1.2 Raw Materials Utilized for Fe
Page 92 and 93: help design large anaerobic digeste
Page 94 and 95: Inlet and outlet of the biodigester
Page 96 and 97: CHAPTER X IMPLICATIONS OF BIOGAS ON
Page 100 and 101: 10.8 CARBON EMISSION SAVED FROM THE
Page 102 and 103: industrial, military or other organ
Page 104 and 105: apidly. The techniques that have fo
Page 106 and 107: 11.2.7 Contingency Approach The ess
Page 108 and 109: have to deal not only with one leve
Page 110 and 111: REFERENCES [1] CES/IOE (2001) Role
Page 112 and 113: . Internal rates of return (IRRS) a
Page 114 and 115: Other assumptions made while calcul
Page 116 and 117: Table 12.1: Summary of Financial Ra
Page 118 and 119: Table 12.4: Summary of Financial Ra
Page 120 and 121: Table 12.7: Financial Rates of Retu
Page 122 and 123: IRRs are higher when increased nutr
Page 124 and 125: CHAPTER XIII BIOGAS POTENTIAL AND F
Page 126 and 127: would be available since the number
Page 128 and 129: 13.2 FUTURE PERSPECTIVE IN NEPAL 13
Page 130 and 131: 13.3.1 Institutional Strengthening
Page 132 and 133: ■ ■ Reducing dependency on impo
Page 134 and 135: CHAPTER XIV ROLE OF VARIOUS ACTORS
Page 136 and 137: ■ ■ ■ To construct 13,000 bio
Page 138 and 139: utilization of bio-slurry as fertil
Page 140 and 141: and NBPG. Sometimes a company may b
Page 142 and 143: CHAPTERXVI IMPACT OF BIOGAS ON USER
Page 144 and 145: of dung, On the other hand, 33 perc
Page 146 and 147: CHAPTER XVII IMPACT OF BIOGAS ON HE
Page 148 and 149:
Figure 17.1: Perceived Reduction in
Page 150 and 151:
27 percent of households with bioga
Page 152 and 153:
Majority of biogas households (95.5
Page 154 and 155:
Table 18,1: Sampling of Biogas Hous
Page 156 and 157:
as the probable reasons for non-ope
Page 158 and 159:
Table 18.7 shows that majority of t
Page 160 and 161:
variations. Assuming that 1 hour of
Page 162 and 163:
Status Table 18.15: Comparison of t
Page 164 and 165:
contributes to the saving of Rs. 6.
Page 166 and 167:
Table 18.22: Kerosene Replacement a
Page 168 and 169:
The survey results on Carbon emissi
Page 170 and 171:
CHAPTER XIX WORKLOAD OF WOMEN AND G
Page 172 and 173:
Looking into the division of activi
Page 174 and 175:
19.3 STUDIES OF BIOGAS USERS WITH F
Page 176 and 177:
co-operative manner so that the wea
Page 178 and 179:
Biogas user women perceived that bi
Page 180 and 181:
20.1 INTRODUCTION CHAPTER XX FINANC
Page 182 and 183:
portion of the construction cost of
Page 184 and 185:
CHAPTER XXI CONSTRAINTS AND PROBLEM
Page 186 and 187:
21.6.4 Mosquito Breeding after Biog
Page 188 and 189:
(FAOm:P/Nep/4451-T). [33] CMS (1996
show all

download (pdf, 6MB) - SNV

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?