Evaluating greenhouse gas emission reduction from piggery waste, agricultural by products and domestic solid waste treatment at pilot scale in rural area of northern Vietnam

VIETNAM NATIONAL UNIVERSITY, HANOI VIETNAM JAPAN UNIVERSITY PHAM VIET BIEN CUONG EVALUATING GREENHOUSE GAS EMISSION REDUCTION FROM PIGGERY WASTE, AGRICULTURAL BY PRODUCTS AND DOMESTIC SOLID WASTE TREATMENT AT PILOT SCALE IN RURAL AREA OF NORTHERN VIETNAM MAJOR: ENVIRONMENTAL ENGINEERING (PILOT) SUPERVISORS: ASSOC PROF DO QUANG TRUNG PROF MASAKI TAKAOKA Ha Noi, 2019 ACKNOWLEDGMENTS In order to implement this thesis, I have received a plenty of supports from everybody First of all, I would like to convey my gratefulness to my teachers at Japan as well as Vietnam Thank you so much, Professor Masaki TAKAOKA who is so dedicated and enthusiastic, is my supervisor He has helped me to orient my master thesis detail and found more new points I would especially like to thank Assoc Prof Do Quang TRUNG as well as team members in his project spending on more one year with me My thanks and appreciation also to managers of Kikugawa biogas power plant; Kikugawa research center and Yagi biology center where I came and conducted data Thank Mr.TOI who is owner of piggery farm in Lam Dien commune and Mr MANH in Hai Dong commune also I have not been forgetting supports from Mrs MISHINA in whole my internship in Japan Mr Takashi SUZUE was head of VJU’s internship delegation at SHIMADZU corporation Professor Seiji HASHIMOTO; Keisuke SATO and other teacher at Ritsumeikan University held several informative field tours in Japan for conducting data Once again, I want to thank appreciate to JICA (Japan International Cooperation Agency) for specially supporting VJU's student and me in these two years Sincerely! PHAM VIET BIEN CUONG MEE Master’s student Vietnam Japan University i TABLE OF CONTENTS ACKNOWLEDGMENTS i TABLE OF CONTENTS ii LIST OF FIGURES iv LIST OF TABLES v LIST OF ABBREVIATIONS vi INTRODUCTION .vii CONTENTS CHAPTER 1: LITERATURE REVIEW 1.1 Greenhouse gas emission issues 1.1.1 Greenhouse effect and Greenhouse gases 1.1.2 Greenhouse gases emission situation 1.1.3 Greenhouse gases emission data and estimation 1.2 The issues in waste management of Vietnam 1.2.1 Pig manure, agricultural by product and domestic waste 1.2.2 Solutions 12 CHAPTER 2: METHODOLOGY 16 2.1 Concept of estimating emission reduction 16 2.2 Approaches of estimating GHGs emission 17 2.3 CH4 emission in solid waste management 18 2.4 Calculation GHGs emission in livestock management 20 2.4.1 Baseline emission 20 2.4.2 Project activities in emission reduction 23 2.4.3 Emission reduction applies in case of Vietnam 25 2.5 Co-digestion pilot model in rural area of northern Vietnam 26 CHAPTER 3: RESULTS AND DISCUSSIONS 30 3.1 GHGs emission from livestock management of Vietnam 30 3.2 GHGs emission reduction from livestock management of Japan 32 3.3 Estimation GHGs emission reduction from manure management at pilots in Vietnam 34 ii 3.3.1 General information 34 3.3.2 Estimation of Baseline emission 34 3.3.3 Estimation of emission reduction 38 CONCLUSION 40 REFERENCES 41 ANNEXES 44 iii LIST OF FIGURES Figure 1.1: Greenhouse effect (US-EPA) Figure 1.2: Global anthropogenic GHG emissions Figure 1.3: Greenhouse gas emissions by sectors Figure 1.4: Agricultural emission total and manure management of the world Figure 1.5: A forecasting global GHGs to 2030 Figure 1.6: Agricultural emissions by sector Figure 1.7: Share of sectors in manure management Figure 1.8: Approaches way in estimating GHGs emission Figure 1.9: GHGs emission sources in AFOLU sector Figure 1.10: Volume of manure in livestock of Vietnam 2010-2014 Figure 1.11: Animal waste discharged by economic region of Vietnam 2014 10 Figure 1.12: The contribution of domestic waste in Vietnam' rural (2007) 11 Figure 1.13: Waste treatment in ASEAN 12 Figure 1.14: Dehydrate system of livestock treatment in visited center in Japan 13 Figure 2.1: Concept of Baseline emission 20 Figure 2.2: Project activities for GHGs emission reduction 24 Figure 2.3: The steps of raw material pre-treatment for co-digestion system 28 Figure 3.1: Contribution of total agricultural emission in total GHG emission of Vietnam 30 Figure 3.2: Contribution of GHG emission of agriculture in Vietnam 30 Figure 3.3: Agricultural emission total between Vietnam and Japan 31 Figure 3.4: Estimating evolutions of Methane (CH4) emission and swine population of Ha Noi from 1995 to 2017 31 Figure 3.5: Emission from traditional biogas of Mr.Toi's farm and Mr Manh’s farm 35 Figure 3.6: Emission reduction potential commune scale 39 iv LIST OF TABLES Table 1.1: Main sources of GHG emission Table 1.2: Top 10 emitters (CO2 equivalent) average 1961 - 2016, Agriculture total (FAO) Table 1.3: Solid waste in livestock of Vietnam Table 1.4: GHG emission in livestock by economic region sectors, 10 Table 1.5: Summary of studies regard to co-digestion 14 Table 2.1: DOC and DOCf of typical solid waste 19 Table 2.2: Steps of estimating CH4 emission 22 Table 2.3: Japanese estimation methodology in agricultural sector 23 Table 2.4: Steps of CH4 estimation in biological treatment 23 Table 2.5: Co-digestion system mode 29 Table 3.1: The results are calculated and analyzed from Kikugawa biogas power plant survey 33 Table 3.2: Initial estimation the livestock excretion and CH4 emission 33 Table 3.3: Calculation CH4 emission following IPCC volume for biological solid waste treatment 34 Table 3.4: Estimation of Lam Dien and Hai Dong emission reduction 35 Table 3.5: Emission of agricultural by-product and domestic waste 37 Table 3.6: Total emission 37 Table 3.7: Emission reduction potential 38 v LIST OF ABBREVIATIONS GHGs MONRE IPCC UNFCCC AFOLU DOC BE ER OM CO2eq Kt COD TS DS SS Gg Temp Greenhouse Gases Vietnam Ministry of Natural Resources and Environment Intergovernmental Panel on Climate Change United Nations Framework Convention on Climate Agriculture, Forestry and Other Land Use Degradable organic carbon Baseline emission Emission Reduction Organic Matter Carbon dioxide equivalent Kilo tone Chemical Oxygen Demand Total Solid Dissolve Solid Suspended Solid Giga-gram Temperature vi INTRODUCTION According to Vietnam national environmental report (2014), rural environment has been degrading faster than forecasted Especially as northern rural area of Vietnam, water, solid and air pollution are big issues Moreover, GHGs emission was mentioned in another national report of MONRE about environment of Vietnam phase 2011-2015 Agricultural activities will be affected serious [1] [2] The fact that emission from agriculture contributes greater than 40% in total emission of Vietnam and 60% of it comes from agricultural methane emissions activities Controlling methane (CH4) emission from manure management is necessary but it does not really take care properly Biogas technique which is one traditional treatment, is very popular in Vietnam and simplify to operate for farmers However, it seems overload to treat a large of waste as well as operates in substrate shortage status; we need to spend more area expending biogas tank capacity After harvesting, farmer disposes of a lot of agricultural residues; almost them decay into the environment, a small part is used for other purposes (animal feed, composting, ) In order to solute two these issues, co-digestion pilot model gained many positive performances due to mixing both agricultural by product and swine manure In Japan, there are many factories applied co-digestion in treatment manure with food waste, agricultural residues ; if possible, anaerobic co-digestion could solve waste from livestock and agricultural production in Vietnam It could help C:N ratio suitably for anaerobic digestion process and reduction somewhat GHGs emission Estimating GHGs emission in manure management is based on guidelines, tools of IPCC, UNFCC and refers Japanese method while global and national emission are analyzed from many famous organizations (World Bank, FAO, OECD) Research purpose In this thesis, I want to apply several simple approaches in estimating GHGs emissions in case Vietnam and evaluating the efficiency of emission reduction activities On the other hand, it could find out a GHGs emission trend of the world as vii well as Vietnam by exploiting inventories data of the international organizations (FAO, OECD, World Bank) Research object In this thesis, methane (CH4) emission was focused mainly on researching in agricultural emission (manure management) and solid waste management (agricultural by-product and domestic waste) Co-digestion model is applied for reducing emission in pilot scale Research scope Two places were chosen are rural area of northern of Vietnam with special outstanding characteristics:  Experimental model 1: at Hai Dong commune, Nam Dinh province It is coastal area where has been impacted ocean level rise of climate change  Experimental model 2: at Lam Dien commune, Ha Noi’s countryside It has a supply function for cities (e.g Ha Noi city) Due to near the developing cities strongly, the environment in here was affected seriously In addition, the fast growth of piggery farms is not planned All of researches and results in my thesis is performed by 03 chapter below: “Chapter I: Literature review”: Introduce general information about GHGs emission and several problems of Vietnam’s rural in waste management “Chapter II: Methodology”: Making co-digestion pilots and method of estimating emission will be shown in this chapter “Chapter III: Results and discussions”: Summarize and analyze the results of this research regarding CH4 emission estimation and the effective co-digestion model in emission reduction viii CONTENTS CHAPTER 1: LITERATURE REVIEW 1.1 Greenhouse gas emission issues 1.1.1 Greenhouse effect and Greenhouse gases Greenhouse gases (GHGs) are gaseous component of the atmosphere However, clouds and they absorb and emit radiation at specific wavelengths within the spectrum of thermal infrared radiation emitted by the Earth’s surface This property causes the greenhouse effect Methane (CH4), carbon dioxide (CO2), nitrous oxide (N2O), zone (O3) and water vapor (H2O) are the main GHGs in the Earth’s atmosphere (Tab.1.1) [3] According to Montreal Protocol, the chlorine and bromine containing substances and the halocarbons are included Besides CH4, N2O and CO2, sulphur hexafluoride (SF6), hydrofluorocarbons (HFCs) and perfluorocarbons (PFCs) are dealt with in the Kyoto Protocol [3] Table 1.1: Main sources of GHG emission [4] CH4 emission Methane (CH4) emission is from the transport of coal, natural gas, and oil and produce activities Decomposition of organic wastes in municipal solid waste (MSW), in agriculture, landfills also generate it Estimating methane emissions from livestock relate to animal species, feeding, performance and gross energy The calculations are based on conversion factors for each field N2O emission CO2 emission Nitrous oxide (N2O) is Carbon dioxide (CO2) is emitted from industrial and agricultural activities, even comes a part of combustion of fossil fuels or solid waste emitted to atmosphere via burning such as fossil fuels (e.g oil, coal and natural gas), wood, solid waste or made from chemical reactions Carbon dioxide could get rid of the atmosphere by plants or participate in carbon cycle Greenhouse effect is known as phenomenon in which GHGs absorb thermal infrared radiation and then emitted again to the Earth’s surface as well as the atmosphere Because of emission all sides, GHGs create a trap heat at surfacetroposphere layer This phenomenon is the greenhouse effect (Fig.1.1) The fact that [27] Rebecca Rosen, Anne Choate, Philip Groth, Deanna Lizas, "Evaluation of Greenhouse Gas Emissions and Reduction Strategies Related to Waste Management by Local Government", 2010 [28] Tufaner F, Avşar Y, "Effects of co-substrate on biogas production from cattle manure: a review", International Journal of Environmental Science and Technology, vol 3, no 9, pp 2303-2312, 2016 [29] Soheil A Neshata, Maedeh Mohammadia, Ghasem D Najafpoura, Pooya Lahijani, "Anaerobic co-digestion of animal manures and lignocellulosic residues as a potent approach for sustainable biogas production", Renewable and Sustainable Energy Reviews, no 79, pp 308322, 2017 [30] S.D Kalamaras, T.A Kotsopoulos, "Anaerobic co-digestion of cattle manure and alternative crops for the substitution of maize in South Europe", Bioresource Technology, vol 172, pp 68-75, 2014 [31] Nguyen Vo Chau Ngan, Le Hoang Viet, Nguyen Xuan Hoang, " Tinh toan phat thai Me-Tan tu rac thai sinh hoat khu vuc noi o Can Tho", Khoa hoc Truong Dai hoc Can Tho, vol A, Khoa hoc Tu nhien, Cong Nghe va Moi truong, pp 99-105, 2014 43 ANNEXES Part A Annex A.1: Top 20 At risk countries of sea level rise (b) (https://www.climatecentral.org/news/new-analysis-global-exposure-to-sea-level-rise-flooding18066) 44 Annex A.2: Top 20 At risk countries of sea level rise (a) Annex A.3: Annual GHGs emission by sector [3] 45 Annex A.4: Emissions by country (CO2 equivalent) Agriculture total + (Total) Average 1961 – 2016 (Source: FAO) Annex A.5: Agricultural emissions by continent, total CO2eq (FAO) 46 Annex A.6: Agricultural emission data of FAO Unit: Gg CO2 eq/year (shortlist) Type Year 1961 World 2751637 Vietnam 27452.88 Japan 27251.21 World 250724.1 Vietnam 2070.773 Japan 1146.342 Agriculture total 1962 2813174 28154.28 27742.41 255929 2089.341 1310.863 1963 2850169 27070.13 27861.7 258993.2 2232.577 1302.103 Manure management 1964 2910291 29073.31 27659.26 259644.1 2290.509 1338.514 1965 2971287 28344.02 27425.85 264452.4 2281.506 1338.365 1966 3050263 27702.6 27400.91 268131.2 2285.13 1354.739 1967 3121617 28287.85 27975.8 275822 2233.904 1450.781 1968 3181062 28718.95 28431.11 278387 2295.075 1501.058 1969 3211697 29489.25 28734.44 278077.2 2346.657 1609.72 1970 3255846 28673.55 27135.03 279653 2379.39 1748.223 1971 3325739 28297.92 26073.07 290100.7 2401.898 1810.591 1972 3375567 29226.04 26103.81 295847.2 2425.724 1796.5 1973 3449262 29918.27 26616.29 299679.2 2583.387 1825.796 1974 3505366 30393.6 26401.83 304138.8 2659.904 1880.127 1975 3601518 28787.62 26282.73 304397.7 2202.382 1843.846 1976 3632685 30419.45 26681.66 302652.1 1856.49 1849.14 1977 3674054 32154.69 27160.48 306063.1 2274.462 1951.991 1978 3727198 31629.71 26618.66 309462.1 2298.201 2052.99 1979 3759287 31235.11 27102.21 314097.9 2362.245 2150.715 1980 3831087 31880.82 25585.69 319883.9 2475.458 2206.458 1981 3859882 33057.95 25606.95 319830.6 2594.509 2248.695 1982 3887402 34151.23 26001.14 320934.4 2698.744 2283.683 1983 3939066 35025.91 26417.47 322769.9 2831.816 2332.06 1984 3997993 35814.87 26896.25 326917.2 2988.036 2376.97 1985 4010266 36665.55 26990.59 328615.2 3049.46 2408.626 1986 4053890 37333.94 27049.45 332480.3 3116.063 2453.213 1987 4068920 36930.02 26110.06 332674.1 3216.975 2471.608 1988 4124362 38587.73 25738.33 332391.3 3205.401 2495.237 1989 4181728 39695.38 25744.59 335167.7 3330.999 2508.788 1990 4611569 40831.78 26243.17 335770.3 3316.452 2515.002 1991 4596111 43140.21 25928.61 336180.2 3322.444 2504.859 1992 4576219 43944.9 26360.04 330876 3597.555 2512.832 1993 4549419 45070.16 26560.86 329093.2 3797.613 2512.07 1994 4584098 47685.1 26855.32 330989.1 3940.312 2479.973 1995 4640193 48431.46 25781.12 331273.7 4085.19 2422.723 1996 4777441 51063.22 24811.46 331947.4 4225.455 2371.409 1997 4737414 51234.44 24442.26 320008.4 4355.225 2346.414 1998 4847098 54584.92 23478.65 320955.2 4455.513 2336.063 1999 4875314 56375.5 23333.06 321212.1 4592.912 2312.271 47 2000 4805153 57429.91 23189.57 322252.6 4819.861 2284.952 2001 4717882 54838.45 22726.86 319911.6 4998.196 2263.402 2002 4748158 56212.1 22953.76 321645.2 5237.011 2251.961 2003 4742248 57700.68 22795.28 322246.4 5598.336 2246.54 2004 4844425 60726.4 23013.96 322601.9 5871.573 2229.093 2005 4873930 58407.73 22779.58 324349 6220.078 2184.395 2006 4924994 59288.19 22536.13 327715.1 6351.481 2198.005 2007 5008613 60524.79 22429.99 329514 6405.484 2219.925 2008 5020988 59854.09 21930.97 333297.8 6322.905 2219.069 2009 5019933 63395.54 21646.5 334323.8 6425.68 2225.754 2010 5088714 60719.61 21640.92 336655.6 6327.412 2206.4 2011 5220747 59454.99 20641.85 336052.8 6207.816 2068.298 2012 5241381 60647.04 20102.86 337542.4 6034.959 2044.459 2013 5184924 64228.67 20488.31 337808.9 5987.682 2128.412 2014 5238034 62404.13 20376.22 341418.4 6094.361 2096.095 2015 5259816 64953.57 19711.09 345069 6302.357 2092.314 2016 5285846 65223.58 19323.8 348559.5 6545.585 2047.769 Annex A.7: Total solid waste generated (2003 and 2008) [11] 48 Annex A.8: Utilize biogas Utilize biogas Mr.Toi's farm Mr.Manh's farm Lam Dien commune Hai Dong commune Average of used biogas per day m3/d 1.90 0.99 42.27 39.29 Component of biogas %CH4 (Average) 65.0 62.2 64.4 63.0 Volume of CH4 m3 CH4/d 1.24 0.62 27.22 24.75 m3 CH4/year 451.40 225.70 9936.90 9034.10 Emission ton CO2eq/year 7.4 3.7 162.9 148.1 Annex A.9: Mr.Toi's farm, co-digestion with agricultural residues Input Parameter Unit TN1 pH CODs TP NH4+-N TN TS – mgO2/L mg/L mg/L mg/L g/L 6.6 ± 0.1 3,550 ± 167 105.9 ± 4.1 327.6 ± 1.8 396.2 ± 2.0 8.5 ± 0.1 Parameter pH CODs TP Unit – mgO2/L mg/L NH4+-N TN2 TN3 TN4 6.8 ± 0.1 8,171 ± 250 97.3 ± 3.5 285.2 ± 1.8 342.2 ± 1.6 18.9 ± 0.3 6.7 ± 0.1 3,200 ± 150 88 ± 3.1 264 ± 1.2 320 ± 1.1 6.8± 0.3 TN1 7.0 ± 0.1 1,357 ± 109 102.1 ± 2.1 6.8 ± 0.1 6,751 ± 211 96.8 ± 3.2 290.5 ± 1.6 350.7 ± 1.3 14.2 ± 0.2 Output TN2 7.1 ± 0.1 2,132 ± 193 92.7 ± 1.2 TN3 7.0 ± 0.1 2,502 ± 152 94.8 ± 2.2 TN4 7.0 ± 0.1 902 ± 160 81.6 ± 2.0 mg/L 247.5 ± 1.5 182.0 ± 1.1 184.0 ± 1.8 195 ± 1.2 TS g/L 3.8 ± 0.1 5.7 ± 0.1 6.9 ± 0.01 3.1 ± 0.1 φ (COD removal efficiency) % 61.8 68.5 69.4 71.8 49 Annex A.10: Mr.Manh's farm, co-digestion with domestic waste Input Parameter Unit TN1 TN2 TN3 TN4 pH – 6.8 ± 0.1 6.9 ± 0.1 6.8 ± 0.1 6.8 ± 0.1 CODs mgO2/L 3,030 ± 150 5,450 ± 120 6,980 ± 200 2,490 ± 170 TP mg/L 96 ± 4.3 175 ± 2.2 221 ± 4.5 77 ± NH4+-N mg/L 290 ± 5.8 522 ± 2.3 660 ± 1.8 232 ± 3.1 TN mg/L 579 ± 1.3 g/L 730 ± 1.5 18.680 ± 0.289 256.8 ± 1.3 TS 320 ± 3.5 8.125 ± 0.511 14.113± 0.237 6.500 ± 0.210 Output Parameter Unit TN1 TN2 TN3 TN4 pH – 7.1 ± 0.1 7.0 ± 0.1 7.0 ± 0.1 7.1 ± 0.1 CODs mgO2/L 1,061 ± 98 1,635 ± 193 2,164 ± 145 747 ± 130 TP mg/L 34 ± 2.5 61.2 ± 1.0 78.2 ± 2.8 27.2 ± 1.0 + NH4 -N mg/L 110 ± 3.5 110 ± 1.5 255 ± 1.5 110 ± 1.5 TS g/L 1.500 ± 0.010 2.700 ± 0.021 3.460 ± 0.020 1.250 ± 0.017 φ (COD removal efficiency) % 65.0 70.0 69.0 71.0 Volume of biogas (L) TN1 170 150 130 110 90 70 50 30 10 -10 TN2 TN3 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Time of decay (day) Annex A.11: Volume of biogas from experiments 50 Annex A 12: Emission reduction calculations (Hai Dong commune) Estimation CH4 following AMS-UNFCCC anaerobic technology Farm General info Number Annual of each population swine Global warming potential Q CODin CODout MCF1 Bo UF GWP MFC3 BE1 BE2 BE y Head head/year m3/y t/m3 t/m3 methane correction factor Maximum CH4 producing capacity kg CH4/kg COD Model correctio n factor Mr.Manh 500 452 7,500 3.03 1.06 0.80 0.25 0.890 25 0.10 65.6 4.4 70.1 Mr.Manh-reduce water 500 452 6,300 3.03 0.91 0.80 0.25 0.890 25 0.10 59.4 3.2 62.6 Mr.ManhCodigestion 10% 500 452 6,300 3.03 0.88 0.80 0.25 0.890 25 0.10 60.2 3.1 63.3 Mr.ManhCodigestion 15% 500 452 6,300 3.03 0.94 0.80 0.25 0.890 25 0.10 58.5 3.3 61.8 Hai Dong (Codigestion) 20,000 18,082 252,000 3.03 0.88 0.80 0.25 0.890 25 0.10 2409.3 123.0 2532.3 Hai Dong (biogas) 20,000 18,082 300,000 3.03 1.06 0.80 0.25 0.890 25 0.10 2625.8 176.7 2802.5 methane correction factor ton CO2eq/year Annex A 13: Emission reduction calculations (Lam Dien commune) Estimation CH4 following AMS-UNFCCC anaerobic technology Farm General info Number Annual of each population swine Global warming potential Q CODin CODout MCF1 Bo UF GWP MFC3 BE1 BE2 BE y Head head/year m3/y t/m3 t/m3 methane correction factor Maximum CH4 producing capacity kg CH4/kg COD Model correctio n factor Mr Toi 1,200 1,085 15,000 3.55 1.35 0.80 0.25 0.890 25 0.10 146.9 11.3 158.1 Mr.Toi-reduce water 1,200 1,085 12,900 3.55 1.00 0.80 0.25 0.890 25 0.10 146.3 7.2 153.5 Mr.ToiCodigestion 10% 1,200 1,085 12,900 3.55 1.12 0.80 0.25 0.890 25 0.10 139.6 8.0 147.6 Mr.ToiCodigestion 15% 1,200 1,085 12,900 3.55 1.09 0.80 0.25 0.890 25 0.10 141.4 7.8 149.2 Lam Dien (codigestion) 26,400 23,868 283,800 3.55 1.12 0.80 0.25 0.890 25 0.10 3071.1 176.5 3247.6 Lam Dien (biogas) 26,400 23,868 330,000 3.55 1.35 0.80 0.25 0.890 25 0.10 3230.7 247.8 3478.5 methane correction factor ton CO2eq/year Annex A.14: COD removal efficiency Unit TN1 (Origin) TN2 (Mix10) TN3 (Mix15) TN4 (Reduce water) Mr.Toi's farm % 61.8 68.5 69.4 71.8 Mr.Manh's farm % 65.0 70.0 69.0 71.0 φ (COD removal efficiency) 51 Annex A.15: Emission of co-digestion and traditional biogas at Mr.Manh's farm Mr.Manh's farm IPCC UNFCCC Japan (*) Mr.Manh's farm IPCC UNFCCC Japan (*) BE Traditional biogas ER Efficiency ton CO2eq/year 64.8 108.8 64.8 ton CO2eq/year 25.3 73.2 8.3 ton CO2eq/year 39.5 35.6 56.6 % 61.0 32.7 87.2 BE ton CO2eq/year 64.8 108.8 64.8 Co-digestion ton CO2eq/year 22.1 61.8 5.1 ER ton CO2eq/year 42.7 47.0 59.7 Efficiency % 65.9 43.2 92.2 Annex A.16: Emission of Co-digestion and traditional biogas at Mr.Toi's farm Mr.Toi's farm IPCC UNFCCC Japan (*) Mr.Toi's farm IPCC UNFCCC Japan (*) BE ton CO2eq/year 150.7 256.3 150.7 Traditional biogas ton CO2eq/year 55.8 160.9 15.0 RE ton CO2eq/year 94.8 95.4 135.7 Efficiency % 62.9 37.2 90.1 BE Co-digestion RE Efficiency ton CO2eq/year 150.7 256.3 150.7 ton CO2eq/year 53.1 147.6 12.2 ton CO2eq/year 97.6 108.7 138.5 % 64.8 42.4 91.9 52 Annex A.17: Decision tree for CH4 emissions from Manure Management [17] 53 Part B: Emission factors Annex B.1: Annual average population [17] Annex B.2: Emission factors for CH4 and N20 in biological treatment [18] 54 Annex B.3: Amount of feces and urine excreted and nitrogen content [24] Annex B.4: Nitrogen content amount in feces excreted [24] Annex B.5: Organic matter content in urine and feces [24] 55 Annex B.6: CH4 emission factors for each method of treating manure [24] Annex B.7: Default dry matter content, DOC content and total carbon content [18] 56 Annex B.8: The convert factor to CO2eq (EPA) 57