Reporting Biogas Data from Various Feedstock

International Journal of Formal Sciences: Current and Future Research Trends (IJFSCFRT) ISSN (Print) , ISSN (Online) © International Scientific Research and Researchers Association https://ijfscfrtjournal.isrra.org/index.php/Formal_Sciences_Journal/index Reporting Biogas Data from Various Feedstock Abdulhalim Musa Abubakara*, Mujahid Umar Yunusb a Department of Chemical Engineering, Faculty of Engineering, Modibbo Adama University (MAU), P.M.B 2076, Yola, Adamawa State, Nigeria b Department of Chemical Engineering, Faculty of Engineering, University of Maiduguri (UNIMAID), P.M.B 1069, Maiduguri, Borno State, Nigeria a Email: abdulhalim@mautech.edu.ng b Email: mujahidumaryunus@gmail.com Abstract The knowledge of nutrient composition of specific substrate(s) for anaerobic digestion for the production of biogas can provide first-hand information on the possible outcome of digesting such feedstock. It will also help in planning the construction of large-scale biogas plants based on the awareness of the substrates output quantity of biodegradation products. This paper aims to present feedstock information, yield of the bioprocess and bioenergy capacity of products from anaerobic digestion for comparison, studies and analysis. Keywords: Biogas yield; Bioenergy; Electricity generation; Biogas potential; Feedstock Type. 1. Introduction Biogas is produced conventionally using fixed-domed digester, tubular or balloon bioreactor, floating drum reactor and fiberglass biodigester which is initiated by injecting organic waste feedstock to be degraded by anaerobic bacteria at suitable temperature and pH. Biogas is a colorless gas composed of majority of methane (CH4) and carbon dioxide (CO2) with small concentrations of other gases. Usually, substrates used for anaerobic digestion falls under either of agricultural, industrial or municipal waste. Often times in the literature, characteristics and biogas potential of single or multiple feedstock that had undergone anaerobic process are reported. Due to the fact that anaerobic digestion for biogas production is carried out at various conditions that gives desirable amount of product, literature information or results documented by researchers are most times insufficient. Despite the multitude papers and publications on diverse feedstock, work on anaerobic digestion for biogas production is still encouraged. Production of biogas can be done utilizing lots of organic waste feedstock as shown in Fig. 1. Few among these substrates are captured by this paper in Table 1, 3-5 and 8-9. It is a random data on the amount of heat, electricity, biofertilizer and biogas/biomethane potential of some selected feedstock based on known amount of substrate sample taken for digestion and percent dry matter, volatile solids and moisture content present. -----------------------------------------------------------------------* Corresponding author. 23 International Journal of Formal Sciences: Current and Future Research Trends (IJFSCFRT) (2021) Volume 11, No 1, pp 23-36 The tables reported mostly, manures, energy crops and crop waste excluding wastewater from industries such as textile, beverage, dairy, pharmaceutical and sugar industries. Chicken and bovine manure are among the highest most explored manures for anaerobic digestion. Table 2, 6 and 7 therefore singled out chicken manure for data fitting with model equations from Polymath regression software. Other poultry birds like duck and turkey are hardly given attention. Abdallah and his colleagues (2018)’s work on cow manure (a member of the cattle group – bovine) gives a methane yield in the range of 148-216 L CH4/kgVS while that of Mohammed and his colleagues (2019) from paunch manure produces fairly considerable litres of biogas for the period of 49 days it was experimented. Though, a horse is capable of producing 50 kg of dung per day [1] from horses used for sports, work and leisure [2], it is less utilized for biogas production. Figure 1: Some Feedstock for Anaerobic Digestion The selection of organic substrate(s) for anaerobic digestion often depends on several factors which includes availability, nutrient content and quantity. Oat is among the most nutrient-dense foods with the benefit of controlling blood sugar, lowering cholesterol level, relieving constipation, reducing the risk of asthma in infants, skin care for reduction of inflammation, cleansing, moisturizing and soothing dry itchy skin, and the production of biogas. The challenges of the use of oat is that, it is a scarce material or feedstock which cannot serve a large scale production of biogas. 2. Biogas Feedstock and Biogas to Bioenergy Data The product of anaerobic digestion of organic substrates are biogas and biofertilizer. Biofertilizer are used in farms for improved growth and bumper harvest of planted crops as alternative to chemical fertilizer. Biogas then goes to heat and electricity generation after been clean or refined via different types of treatment method to remove impurities and to make them a suitable substitute to natural gas. The feedstock of anaerobic digestion are often characterized to determine the carbon content, percent total solids, volatile solid percentage, ash 24 International Journal of Formal Sciences: Current and Future Research Trends (IJFSCFRT) (2021) Volume 11, No 1, pp 23-36 content, nitrogen level, moisture content among others to know the required level that will effectively produce the desired amount of biogas from the channeled feedstock. Sometimes available literature values of these compositions might be a reasonable guess to carryout anaerobic digestion of a particular feedstock. Figure 2: Substrate(s) Potential of Electricity Generation [3] Operators of biogas plants serving the purpose of generating electricity would be interested in feedstock amount and compositions that is capable of generating high kilo-watt-hour of power if used as substrate (see Fig. 2). Different records of power output of some feedstock are presented in this paper. The largest generators of electricity from biogas is Europe followed by Asia. Biogas is still least exploited in Africa despite shortages in the generation of electricity in the continent. It will be very useful for rural areas in Africa to have biogas plants to meet their energy needs as majority of farmers there still depend on firewood. In the face of increased waste accumulation and the challenges with industrial scale production of biogas, many countries haven’t develop interest to generate power from biogas, but are however, shifting to natural gas as alternative source of fuel [4]. As transportation fuel, biogas is widely used in Indian commercial buses to provide a cheaper means of urban transport to the populace. Table 1 presents heat, biofertilizer and biogas output of four (4) selected manures: Table 1: Annual Biogas Output Information from Manures [1] Substrate Chicken manure Cattle manure (straw bedding) Horse manure (straw bedding) Turkey manure (straw bedding) Amount (tons/yr) 7000 Bio Natural (m3/yr) 462000 3500 Gas Electricity (kWh/yr) 1755600 Heat (kWh/yr) 2079000 Organic (tons/yr) 6860 164500 625100 740250 3430 500 21500 81700 96750 490 2900 252300 958740 1135350 2842 Fertilizer Chicken manure is one of the most widely used substrate channeled for the production of biogas/biofertilizer. Renergon (2021) reported the amount per year of biogas that would be generated based on different weight of chicken manure. Using Polymath 6.10 Educational Release to perform polynomial regression of the chicken manure data in Table 2 gives equation 1: 25 International Journal of Formal Sciences: Current and Future Research Trends (IJFSCFRT) (2021) Volume 11, No 1, pp 23-36 𝐵𝑁𝐺 = 𝑎0 + 𝑎1 𝐴𝐹 + 𝑎2 𝐴𝐹 2 (1) where, 𝐵𝑁𝐺 = bio natural gas generated per year; 𝑎0 = 3.262 × 10−9 , 𝑎1 = 66, 𝑎2 = 3.413 × 10−17 are dimensionless constant parameters; and 𝐴𝐹 = amount of feedstock (or chicken manure) fed in the anaerobic digester annually. Table 2: Biogas Yield based on Amount of Chicken Manure Sample [1] Bio Natural Gas (m3/yr) Amount of feedstock (tons/yr) 264000 4000 363000 5500 719400 10900 422400 6400 178200 2700 950400 14400 752400 11400 844800 12800 204600 3100 125400 1900 92400 1400 547800 8300 Equation 1 is only valid for range of values of AF from 1400-14400 tons/yr. A table similar to Table 1 is Table 3. It is important to know the percent total solids (TS) as well as the percent volatile solid (VS) content of feedstock before anaerobic digestion as stated earlier. Table 3 is based on a constant minimum amount of feedstock of 30000 tons/yr and 5% contamination level. Total solids of eight feedstock with yearly methane yield had been presented graphically in Fig. 3(a) and (b) [3]. Figure 3(a): Cattle and Dry Chicken Manure Yield of Methane with Percent Total Solids Fig. 3(a) and (b) can be used to estimate the biomethane yield of cattle manure, dry chicken manure, canola 26 International Journal of Formal Sciences: Current and Future Research Trends (IJFSCFRT) (2021) Volume 11, No 1, pp 23-36 straw, barley straw, wheat straw, sewage sludge, sunflower straw and corn straw based on the percentage total solid present in them and compared with the empirical values obtained experimentally. The plots are based on 100 tons/yr of substrates following similar trend with Fig. 2 and Table 5. Figure 3(b): Methane Yield of Sewage Sludge and Crop Straws with Percentage Total Solids Biogas yield are often presented in different units. The mathematical relationship (equation 2) [5] can interconvert the biogas yield in (m3/kg total weight) to (m3/kgVS) units: 𝐵𝑖𝑜𝑔𝑎𝑠 𝑦𝑖𝑒𝑙𝑑 ( 𝑚3 𝑘𝑔 𝑜𝑓 𝑤𝑎𝑠𝑡𝑒 ) = 𝐵𝑖𝑜𝑔𝑎𝑠 𝑦𝑖𝑒𝑙𝑑 ( 𝑚3 𝑘𝑔 𝑜𝑓 𝑉𝑆 ) . 𝑇𝑆(%). 𝑉𝑆(%) (2) Table 3: Biomethane Potential (BMP) of Various Feedstock [6] Feedstock %TS %VS BMP Electricity Production (kWh) 9476873 Total Digestate (tons/yr) 500 Biogas Production (m3/yr) 4809375 Chicken boiler 45 75 Chicken layer 25 75 500 2671875 5264930 25267 Cow manure 25 80 450 2565000 5054333 25396 Fat, oils and grease (FOG) Oat Hulls 36 84 1150 9911160 19529941 16507 90 87 242 5400351 10641392 21966 Pig manure 5 80 400 456000 898548 27948 Cheese whey 7 76 700 1061340 2091370 27216 WWTP sludge (5%TS) 5 80 350 399000 786230 28017 WWTP sludge (30%TS) 30 80 350 2394000 4717377 25603 27 2268 International Journal of Formal Sciences: Current and Future Research Trends (IJFSCFRT) (2021) Volume 11, No 1, pp 23-36 Table 4 is the same as Table 3, only that it excludes the percent total solids and volatile solid there in the organic feedstock. More feedstock are reported compared to Table 3. Note that Table 4 is based on 100 tons/day of substrate. Table 4: Heat, Electricity and Biogas Output of Different Substrate [7] Type Pig manure with litter Biogas (m3) 8390 Output Electricity (kWt/h) 1076 Pig manure 7430 797 717 Sheep manure 10800 1064 1101 Cow manure 9000 806 834 Horse manure 6300 619 557 Hens manure 10000 1164 1205 Turkey dung 14030 1407 1456 Paunch manure 6050 595 535 Soy peeling waste 51670 4877 5046 Oat-flakes 61970 5938 6144 Oat 50110 4855 5024 Bran particles 26240 2383 2466 Dry bread 48200 4558 4716 Dairy wastes 67380 8145 8429 Casein 56740 7022 7266 Rape meal 49610 5313 5498 Sunflower meal 48820 5360 5546 Sunflower 59450 6761 6996 Sunflower oil 122260 14889 15407 Sugarbeet leaves ensilage 8820 859 889 Sugarbeet 14710 1338 1385 Haylage 20830 2018 2088 Lucerne 14100 1384 1432 Sudan grass ensilage 9800 923 955 Wheat 59820 5657 5854 Oil seed rape 64450 7583 7847 Potato 17710 1618 1674 Peas 58140 5727 5926 Onion peel 26780 3117 3226 Carrot 7330 681 613 Cauliflower 5920 592 533 Pumpkin 5090 487 576 Glycerine 84570 7573 7837 Linseed oil 122260 14889 15407 Rape-seed oil 119760 14585 15092 28 Generated Heat Production (kWt/h) 1113 International Journal of Formal Sciences: Current and Future Research Trends (IJFSCFRT) (2021) Volume 11, No 1, pp 23-36 Also be reminded that, based on Biteco (2019) and Table 4, 1 ton/day of hens’ manure = 100 m3 of biogas = 10 kWt/h of electricity generated and 13 kWt/h of thermal energy production. For cow manure, 1 ton/day is equivalent to 90 m3 of biogas which is equal to 7 kWt/h of electricity output and 9 kWt/h of thermal energy production. More so, 1 ton/day of sheep manure will give 108 m3 of biogas, 9 kWt/h of electricity and 12 kWt/h of heat. A fifth table (Table 5) gives heat, methane yield and electricity data based on McCabe (2017) for a constant % total solid of 25% and constant flowrate of feedstock of 100 tons/yr: Table 5: Data Based on 100 tons/yr of Feedstock and 25% TS Type Methane 3 Electricity generation Heat generation (m /yr) (kWh/yr) (kWh/yr) Cattle manure 5000 14555 21535 Dry Chicken Manure 5244 15266 22586 Wheat straw 627816 2203559 2059569 Barley straw 470368 1698598 1519419 Canola straw 715963 2512942 2348736 Sunflower straw 603914 2180864 1950813 Corn straw 593828 2144441 1918232 Sugarcane bagasse 779379 2735525 2556774 Potato peels 789675 2771665 2590553 Whey 93254 271468 401647 Sewage sludge 5513 16047 23743 Glycerin 10519 30621 45305 Chicken manure had been distinctively taken from Table 2 for analysis with Polymath regression tool. Table 6 follows the same pattern, but here, amount of feedstock (AF), electricity generation (EG) and heat generation (HG) were taken as independent variable while methane yield (MY) is taken as the dependent variable for a constant total solid content of 60%. Table 6: Chicken Manure Biogas Output Data for 60% TS [3] Amount (tons/yr) 5 Methane (m3/yr) 629 Electricity (kWh/yr) 1832 Generation 10 1259 3664 5421 18 2265 6595 9757 35 4405 12823 18972 56 7048 20517 30356 70 8810 25646 37945 80 10068 29310 43365 100 12586 36638 54207 29 Heat Generation (kWh/yr) 2710 International Journal of Formal Sciences: Current and Future Research Trends (IJFSCFRT) (2021) Volume 11, No 1, pp 23-36 The multiple nonlinear equation gives equation (3); 𝑀𝑌 = 𝑎0 + 𝑎1 𝐴𝐹 + 𝑎2 𝐸𝐺 + 𝑎3 𝐻𝐺 (3) where, the dimensionless constants, 𝑎0 = 0.0099882; 𝑎1 = −396.5288; 𝑎2 = 0.1724653 and; 𝑎3 = 0.847122, for range of AF = 5 − 100 tons/yr, EG = 1832 − 36638 kWh/yr and HG = 2710 − 54207 kWh/yr. Table 7: Poultry Waste Biogas Output with %Dry Matter [8] Poultry droppings Dry matter % Biogas output 3 Poultry litter Biofertilizer Biogas output 3 Biofertilizer (Nm /kg) (tons/yr) (Nm /kg) (tons/yr) 5 0.02063 0.00005 0.01386 0.00005 10 0.04125 0.0001 0.02772 0.0001 20 0.0825 0.00018 0.05544 0.00019 25 0.10313 0.00022 0.0693 0.00023 30 0.12375 0.00026 0.08316 0.00027 50 0.20625 0.00038 0.1386 0.00042 80 0.33 0.00048 0.22176 0.00059 To convert 1 Nm3 to m3, multiply by 10−27 . Table 7 and 8 are from the same source, both reporting waste substrate(s) output of biogas, biofertilizer and other energy data with percent dry matter (DM) for 1 kg of feedstock. Similar table is seen in Table 3 and 9 but with different unit of the biogas production rate. The biogas output of poultry waste in Table 7 is directly proportional to %DM in the feedstock. Dry matter (DM) reflects the residual substance after complete elimination (drying) of water [9]. Common types of drying equipment for DM determination are forced air oven, Koster Tester, microwave, vortex dryer, food dehydrator and NearInfrared Reflectance Spectroscopy (NIRS). To calculate DM of a feed, (i) weigh and record an empty container chosen to hold the material, (ii) put the material on the container and weigh them, i.e. container + sample weight, (iii) calculate the weight of the sample by subtracting weight of the container in (i) from the total weight in (iii), then place in a dryer, (iv) immediately after drying, weigh and record new weight of the container and material, (v) subtract the weight of the container from the weight in (iv) to know the weight of the material after drying and, (vi) divide the mass of the dry feed in (iv) by the mass of the wet material in (iii) and multiply by 100 [10]. These steps are further illustrated using Fig. 4. Mathematically, %𝐷𝑀 = 𝐷𝑊 𝑊𝑊 × 100 (4) where, DW = dry weight of sample and; WW = wet weight of original sample. 30 International Journal of Formal Sciences: Current and Future Research Trends (IJFSCFRT) (2021) Volume 11, No 1, pp 23-36 Figure 4: Procedure of Finding Total Solids Content in Water [11] Dry matter content is simply referred to as total solids (TS) content. It is a term used for material left in a container after evaporation and drying of a sample at 103-105℃ [12]. Moisture content is the amount of water present in the feedstock. The difference in the initial weight (WW) and final weight (DW) of the sample represents the amount of water in the sample [13]. %TS or %DM and % moisture are related using equation 5 and 6: %𝐷𝑀 = 100 − %𝑀𝑜𝑖𝑠𝑡𝑢𝑟𝑒 (5) %𝑀𝑜𝑖𝑠𝑡𝑢𝑟𝑒 = 100 − %𝐷𝑀 (6) Table 8: Important Biogas Data Based on 1 kg of Feedstock [8] Feedstock Dry matter (%) 18 Biogas output (Nm3/kg) 0.05109 Electricity output (kWh) 0.10787 LPG Equivalent (kg) 0.02044 Biofertilizer (tons/yr) 0.00017 CO2 reduction (kg) 39.53971 Slurry output (kg) 0.93869 CH4 Content (%) 55 Cattle manure Poultry litter Poultry droppings Spent grains 25 0.09 0.19 0.036 0.00022 69.6465 0.892 55 38 0.10534 0.22238 0.04213 0.0003 88.92465 0.8736 60 28 0.1155 0.24383 0.0462 0.00024 97.5051 0.8614 60 26 0.13634 0.28784 0.05454 0.00022 113.18324 0.83639 59 Barley straw Glycerin 86 0.31285 0.66046 0.12514 0.00054 220.09054 0.62458 50 98 0.686 1.44822 0.2744 0.00017 482.601 0.1768 50 Potato (whole) Potato peelings 22 0.099 0.209 0.0396 0.00019 73.82529 0.8812 53 11 0.06783 0.1432 0.02713 0.0001 48.67306 0.9186 51 Cattle dung 31 International Journal of Formal Sciences: Current and Future Research Trends (IJFSCFRT) (2021) Volume 11, No 1, pp 23-36 Skimmed milk Grain maize 9 0.0626 0.13215 0.02504 0.00008 51.08274 0.92488 58 85 0.5814 1.2274 0.23256 0.00026 441.73609 0.30232 54 Maize silage Horse manure Turkey manure + straw Rapeseed oil Rapeseed straw Rye meal 32 0.19853 0.41911 0.07941 0.00024 148.04431 0.76177 53 28 0.1176 0.24827 0.04704 0.00024 99.27792 0.85888 60 55 0.21038 0.44413 0.08415 0.00041 177.59858 0.74755 60 99 1.19461 2.52195 0.47784 -0.00043 0.18725 0.3953 0.0749 0.00062 0.43353 0.7753 68 80 1142.9523 8 136.99813 86 0.57792 1.22005 0.23117 0.00026 455.35473 0.3065 56 Sheep manure Pig manure 30 0.02592 0.05472 0.01037 0.00029 20.05819 0.9689 55 23 0.09315 0.19665 0.03726 0.0002 78.63723 0.88822 60 Wheat 86 0.5719 1.20734 0.22876 0.00027 450.61145 0.31372 56 Wheat straw Millet 86 0.29195 0.61634 0.11678 0.00056 209.49657 0.64966 51 31 0.15861 0.33484 0.06344 0.00026 104.21666 0.80967 46.7 Sugarbeet 19 0.14508 0.30628 0.05803 0.00016 101.4514 0.8259 49.7 Grape pomace Cabbage leaves Peanut bran 28 0.0603 0.12729 0.02412 0.00026 47.33862 0.92765 55.8 13 0.06503 0.13728 0.02601 0.00012 50.32037 0.92197 55 93 0.43524 0.91884 0.1741 0.00044 379.67726 0.47771 62 Glycerin 10 0.8415 1.7765 0.3366 -0.00001 591.99525 -0.0098 50 Whey 5 0.0345 0.07283 0.0138 0.00005 25.727 0.9586 53 Rumen content Maize stalk 15 0.06048 0.12768 0.02419 0.00014 46.80245 0.92742 55 50 0.1275 0.26917 0.051 0.00042 93.2841 0.847 52 52 Percent DM or TS is not constant for a particular feedstock. Though there are standards in the literature for comparison of experimental results. For instance, Chastain and his colleagues (2001) compared the TS content of chicken manure with turkey manure where they found that %TS in broiler litter, roaster litter and breeder litter are 78.5, 77.5 and 66.5 respectively; a value approximately closer to turkey manure feedstock. A high total solids level indicates a high level of solid material in the liquid sample [11]. It has been demonstrated in Fig. 3 as well as Table 7, that as the %DM of a specific substrate increases, the biogas or methane output also increase. The amount of material capable of being digested depends on two variables: the TS content and the volatile solids (VS) content of the material added to the bioreactor. Although, %VS content of feedstock are often extracted from the literature by researchers, there exist a formulae for its computation. This is shown in equations (7) and (8): %𝑉𝑆 (𝑚𝑔/𝐿) = 𝑤𝑒𝑖𝑔ℎ𝑡 𝑜𝑓 𝑣𝑜𝑙𝑎𝑡𝑖𝑙𝑒 𝑠𝑜𝑙𝑖𝑑𝑠 %𝑉𝑆 (𝑚𝑔/𝐿) = 𝑤𝑒𝑖𝑔ℎ𝑡 𝑜𝑓 𝑑𝑟𝑦−𝑤𝑒𝑖𝑔ℎ𝑡 𝑜𝑓 𝑎𝑠ℎ 𝑤𝑒𝑖𝑔ℎ𝑡 𝑜𝑓 𝑑𝑟𝑦 𝑠𝑜𝑙𝑖𝑑𝑠 𝑤𝑒𝑖𝑔ℎ𝑡 𝑜𝑓 𝑑𝑟𝑦 𝑠𝑜𝑙𝑖𝑑𝑠 32 × 100 × 100 (7) (8) International Journal of Formal Sciences: Current and Future Research Trends (IJFSCFRT) (2021) Volume 11, No 1, pp 23-36 Table 9: Dry Matter Percent of Various Feedstock with Biogas Yield [14] Feedstock Dry matter percent Biogas Yield (m3/ton) Cattle muck 10 36 Cow milk 13.5 115 Horse excrement 28 63 Pig muck 22.5 74.25 Poultry excrement 15 56.25 Sheep muck 30 108 Maize silage 33 205 Maize grain 87 590 Barley straw 86 312 Barley grain 87 579 Clover hay 86 419 Meadow hay 86 426 Oat straw 86 314 Oat grain 87 501 Rye grain 87 597 Wheat straw 86 292 Wheat grain 87 598 Wheat chaff 89 262 Wheat bran 88 437 Cauliflower 9.6 59 Fodder beet 96.5 715 Fodder carrot 14.6 90 Potato peeling 11 68 Sugar beet 23 147 Sour whey 5.6 37 Glycerin 100 846 Linseed oil 99.9 1223 Rapeseed oil 99.9 1198 Soya oil 99.9 1223 Sunflower oil 99.9 1223 Cheese waste 99.9 674 Old bread 65 482 Carbon-to-nitrogen (C/N) ratio is one of the most vital nutrients necessary for the decomposition of organic substrate to bio natural gas. Nitrogen content is measured using combustion method and Kjeldahl method (TKN). Opinion differs as to the best C:N ratio that is best for anaerobic degradation of waste organic substrate. Generally, a ratio from 25:1 to 30:1 is accepted as the best C/N ratio so far [15]. Table 10 presents 63 substrate materials with their C/N ratios: 33 International Journal of Formal Sciences: Current and Future Research Trends (IJFSCFRT) (2021) Volume 11, No 1, pp 23-36 Table 10: C/N Ratios of Different Feedstock [15]- [16] Feedstock C/N ratio Feedstock C/N ratio Blood meal 43:13 Soybean stalk 33:1.3 Cow manure 12-25:0.6-1.7 Peanut shoots 20-31:0.6 Cow dung 16-25:1.8 Peanut hulls 31:1.7 Chicken dung 5-9.65:3.7-6.3 Peanut shells 35:1 Chicken manure 7-7.3:1-6.3 Potato peels 25:1.5 Poultry bedding 15:1 Potatoes 35-60:1 Poultry manure 5-15:1 Coffee grounds 14-25:1 Pugo 6.74:5 Nut shells 35:1 Waterlily 11.4:2.9 Sugarcane bagasse 140-150:0.3 Horse manure 20-50:1-2.3 Sugarbeet 35-40:1 Rabbit manure 17.9:1 Saw dust 200-600:0.1-1 Deer manure 25.72-30.06:1 Wood chips 25-50:0.1 Goat manure 10-20:1 Newspaper 50-200:1 Pig manure 6-12.5:1-3.8 Tissue paper 70:1 Sheep manure 13-33:1-3.8 Paper 170-173:1 Sheep dung 30-33:1 Cardboard 378:1 Elephant dung 43:1 Rice straw 51-67:0.6 Human excreta 8:1 Corn straw 50:0.8 Legume Hay 17-40:1-2.5 Corn stalk 56.6-75:1-1.2 Hay 12.5-25:1-4 Corn cobs 49.9-123:1 Lucernes 16.6:2.8 Wheat straw 50-150:0.5-1 Algae 75-100:1.9 Oat straw 48-70:0.5-1.1 Cabbage 12.5:3.6 Rye straw 82:1 Tomatoes 12.5:3.3 Silkworm 11.28:1 Alfalfa 12:1 Humus 10:1 Clover 23:1 Sludge 6:1 Mushroom residue 21.96-23.11:1 Hog 13.7:2.8 Grass silage 10-20:1 Carabao 23.1:1.6 Mulberry leaves 14.85:1 Peat moss 58-60:1 Water hyacinth 25:1 Pine needles 60-100:1 Seaweed 70-79:1-1.9 Hairy vetch 11:1 Mustard (runch) 25:1.5 3. Conclusion This work did not report the amount of all nutrient content in feedstock for anaerobic digestion. Essential output data on codigestion of multiple feedstock were not presented too. Also, not all substrates for anaerobic production of biogas were captured. Again some of the data tables appears to be the same. Notwithstanding, this article hopes to provide some relevant data for researchers to compare their empirical biogas data for accuracy and analysis. 34 International Journal of Formal Sciences: Current and Future Research Trends (IJFSCFRT) (2021) Volume 11, No 1, pp 23-36 Acknowledgement BIOGASWORLD, a Canadian knowledge-based company, known for supporting biogas projects worldwide and sharing commercial and technical information to biogas industries, individuals and researchers across the globe, is acknowledged for mailing important information, some of which are presented in this work. BITECO BIOGAS Company founded in 2013 and based in Ukraine and Italy is also acknowledged for mailing bioenergy and biogas output data requested, as they specializes in turnkey construction of state-of-the-art biogas plants in Europe, Asia and CIS countries. References [1] Renergon, "Biogas Calculations: Quick & Easy Real Time Simulation," Anaerobic Digester Calculator, 2021. [Online]. Available: renergon-biogas.com/en/anaerobic-digestion-calculator. [Accessed 17 September 2021]. [2] A. Hadin, Anaerobic Digestion of Horse Manure-Renewable Energy and Plant Nutrients in a Systems Perspective, Gavle: Gavle University Press, 2016, p. 54. [3] B. McCabe, "Calculator for Australian Biogas," Centre for Agricultural Engineering (CAE), University of Southern Queensland (USQ)-Research, 2017. [Online]. Available: biogas.usq.edu.au/calculator/#!/calculate. [Accessed 19 September 2021]. [4] A. Z. Abdul and A. M. Abubakar, "Potential Swing to Natural Gas-Powered Electricity Generation," International Journal of Natural Sciences: Current and Future Research Trends (IJNSCFRT), vol. 10, no. 1, pp. 27-36, 2021. [5] NRREP, Biogas Calculation Tool-User's Guide, Nepal: Alternative Energy Promotion Centre-NRREP, 2014, p. 98. [6] BiogasWorld, "Biogas Calculations," BiogasWorld Media Inc, 2021. [Online]. Available: biogasworld.com/biogas-calculations. [Accessed 23 September 2021]. [7] Biteco, "Biogas Calculator," Biteco Biogas Ltd, 2019. [Online]. Available: biteco-energy.com/biogascalculator. [Accessed 23 September 2021]. [8] A. R. Shukla, "Biogas App," Indian Biogas Association (IBA), 2017. [Online]. Available: https://biogasindia.com. [Accessed 20 September 2021]. [9] R. Braun, P. Weiland and A. Wellinger, Biogas from Energy Crop Digestion, IEA Energy, 2007, p. 20. [10] T. Nennich and L. Chase, "Dry Matter Determination," United States Department of Agriculture (USDA)-Natural Resources Conservation Service (NRCS) CIG, 16 August 2019. [Online]. Available: https://dairy-cattle.extension.org/dry-matter-determination/. [Accessed 24 September 2021]. [11] Corrosionpedia, "Total Solids," Janalta Interactive, 30 December 2020. [Online]. Available: www.corrosionpedia.com/definition-1106-total-solids-water-treatment. [Accessed 25 September 2021]. [12] S. Murphy, "General Infromation on Solids," City of Boulder/USGS Water Quality Monitoring, 2007. [13] J. K. Bernard, "Measuring the Dry Matter Content of Feeds," The Univesity of Georgia (UGA) Extension, 2013. [Online]. 35 Available: International Journal of Formal Sciences: Current and Future Research Trends (IJFSCFRT) (2021) Volume 11, No 1, pp 23-36 https://extension.uga.edu/publications/detail.html?number=SB58&title=Measuring%20the%20Dry%20 Matter%20Content%20of%20Feeds. [Accessed 20 September 2021]. [14] G. Redman, The Anaerobic Digestion Economic Assessment Tool Version 2.2, Nottingham Street: The Andersons Centre, 2010. [15] COC, "The Carbon : Nitrogen Ratio in Composting," Home and Community Composting, 2021. [Online]. Available: www.carryoncomposting.com/416920203. [Accessed 25 September 2021]. [16] K. Hagos, J. Zong, D. Li, C. Liu and X. Lu, "Anaerobic Co-digestion Process for Biogas Production: Progress, Challenges and Perspectives," Renewable and Sustainable Energy Reviews, vol. 76, pp. 14851496, 2017. [17] M. Abdallah, A. Shanableh, M. Adghim, C. Ghenai and S. Saad, "Biogas Production from Different Types of Cow Manure," Advances in Science and Engineering Technology International Conferences (ASET, pp. 1-4, 2018. [18] M. K. Mohammed, G. A. Gasmelseed and M. H. Abuuznien, "Production of Biogas from Cattle Paunch Manure," European Journal of Engineering Research and Science (EJERS), vol. 4, no. 4, pp. 1-3, April 2019. [19] Energypedia, "Nitrogen-Content and C/N-ration of Organic Substrates," 20 January 2015. [Online]. Available: energypedia.info.wiki/nitrogen-content-and-C-N-ratio-of-organic-substrates. [Accessed 1 September 2021]. [20] J. P. Chastain, J. J. Camberato and P. Skewes, "Poultry Manure Production and Nutrient Content," in Nutrient Content of Livestock and Poultry Manure, vol. 32, Clemson University, 2001, p. 17. [21] Homestead, "C:N Ratios of Common Organic Materials," Homestead on the Range, 27 August 2018. [Online]. Available: homesteadontherange.com/2018-08-27-cn-ratios-of-common-organic.materials. [Accessed 19 September 2021]. [22] PNRC, "Carbon-to-Nitrogen Ratios," Planet Natural Research Centre: An Elite Cafemedia Lifestyle Publisher, 2021. [Online]. Available: www.palnetnatural.com/composting-101-making-c-n-ratio. [Accessed 25 September 2021]. [23] L. Malgorzata and J. Frankowski, "The Biogas Production Potential from Silkworm Waste," Waste Management, pp. 564-570, 2018. [24] H. Wang, J. Xu, L. Sheng and X. Liu, "Effect of Addition of Biogas Slurry for Anaerobic Fermentation of Deer Manure on Biogas Production," Energy, vol. 165, pp. 411-418, 2018. [25] M. R. Atelge, D. Krisa, G. Kumar, C. Eskicioglu, D. D. Nguye, S. W. Chang, A. E. Atabari, A. H. AlMuhtaseb and S. Unalan, "Biogas Production from Organic Waste:Recent Progress and Perspectives," Waste and Biomass Valorization, vol. 11, pp. 1-22, 2018. [26] M. C. Caruso, A. Braghieri, A. Capece, F. Napolitano, P. Romano, F. Galgano, G. Altieri, F. Genovese, S. Agrarie and A. Ambientali, "Recent Updates on the Use of Agro-food Waste for Biogas Production," Applied Sciences, vol. 9, no. 6, pp. 1-29, 2019. 36