Effect of Temperature and Retention Time on Methane Production from Beef Cattle Waste

Abstract

The effect of temperature and retention time on the rate of methane production from waste of beef cattle fed a finishing diet was investigated by using continuously mixed 3-liter working volume anaerobic fermentors. The temperatures ranged from 30 to 65�C with 5�C increments between fermentors. The fermentors were fed once per day with 6% volatile solids (organic matter). Retention time for each temperature was varied from 18 to 2.5 days. After 3-volume turnovers, samples were obtained on 4 consecutive days. The highest methane production rate (liters/liter of fermentor per day) and methane yield at that rate (liters/gram of volatile solids) were 1.27 and 0.19 at 9 days and 30�C, 1.60 and 0.16 at 6 days and 35�C, 2.28 and 0.23 at 6 days and 40�C, 2.42 and 0.24 at 6 days and 45�C, 2.83 and 0.14 at 3 days and 50�C, 2.75 and 0.14 at 3 days and 55�C, 3.18 and 0.14 at 2.5 days and 60�C, and 1.69 and 0.17 at 6 days and 65�C. Volatile solids degradation at these retention times and temperatures was between 46 and 54%. The concentrations of volatile acids in the 30 to 55�C fermentors were generally below 2,000 mg/liter, with the exception of the 3-day retention time. The 60 and 65�C fermentors were usually above this level for all retention times. These studies indicate potential rates of methane production from the fermentation of untreated waste of beef cattle fed high-grain finishing diets. This information should serve as preliminary guidelines for various kinetic analyses and aid in economic evaluations of the potential feasibility of fermenting beef cattle waste to methane.

Enhancing the Performance of Anaerobic Digestion of Dairy Manure through Phase‐Separation

“…In the one-phase reactor, the biogas production increased by 56% on increasing the temperature from 25 to 358C. The results obtained are in agreement with previous results, which showed an improvement in biogas yields with increasing temperature [21,22]. In the mesophilic temperature range (25 -358C), higher temperatures tend to give better methane yields.…”

“…These three reactors produced similar percentages of CO2 and N2. R22 (25) did not provide similar results since its biogas production efficiency was significantly lower than the other reactors. It typically contained 40 to 45% CH4, 30 to 35% CO2, and 25 to 30% N2.…”

“…The acidogenic reactors had different biogas compositions and productions than the methanogenic reactors. The gas production in R21 (25) was not considerable and ca. 130 mL gas was produced in R21(35).…”

“…The methane yields of R1(35), R22(35), R1 (25), and R22(25) were calculated as 221, 216, 132 and 43 mL CH4/(g VS added), respectively. The performance of the reactors in terms of biogas yield is comparable with literature values except for reactor R22(25) [23 -25].…”

Use of Wood-Based Materials in Beef Bedded Manure Packs: 2. Effect on Odorous Volatile Organic Compounds, Odor Activity Value,Escherichia coli, and Nutrient Concentrations

“…However, this may reflect the utilization of SCFAs and BCFAs for methanogenesis. Varel et al (1980) reported that VFAs can be used as substrate for methanogenesis. This drop in VFA concentration at Day 21 is reflected in the overall pH values at Day 21 (Table 2).…”