Enhancement of Biogas Production by Co-digestion of Potato Pulp with Cow Manure in a CSTR System

Abstract

Anaerobic digestion (AD) process is a well-established method to generate energy from the organic wastes both from the environmental and economical perspectives. The purpose of present study is to evaluate energy production from potato wastes by incorporating cow manure into the process. Firstly, a laboratory pilot of one-stage biogas production was designed and built according to continuously stirred tank reactor (CSTR) system. The setup was able to automatically control the environmental conditions of the process including temperature, duration, and rate of stirring. AD experiment was exclusively performed on co-digestion of potato peel (PP) and cow manure (CM) in three levels of mixing ratio including 20:80, 50:50, 80:20 (PP:CM), and 0:100 as control treatment based on the volatile solid (VS) weight without adding initial inoculums. After hydraulic retention time (HRT) of 50 days on average 193, 256, 348, and 149 norm liter (LN) (kg VS)(-1), methane was produced for different mixing ratios, respectively. Statistical analysis shows that these gas productions are significantly different. The average energy was determined based on the produced methane which was about 2.8 kWh (kg VS)(-1), implying a significant energy production potential. The average chemical oxygen demand (COD) removal of treatments was about 61%, showing that it can be leached significantly with high organic matter by the employed pilot. The energy efficiency of 92% of the process also showed the optimum control of the process by the pilot.

Kinetic and Enhancement of Biogas Production For The Purpose of Renewable Fuel Generation by Co-digestion of Cow Manure and Corn Straw in A Pilot Scale CSTR System

“…Similar observations have also been reported by Tong et al (2013), Sanaei-Moghadam et al (2014) and Latinwo & Agarry (2015). Both organic loading rates on codigestion of CM and CSR gave better methane yields than single digestion of cow manure (Table 3) In addition, VS reduction upon stable performance as 64.57, 54.96, 74.11 , 62.76 , 64.11 and 58.30% during the runs A to F, respectively.…”

Current status of cow dung as a bioresource for sustainable development

“…Mixture of cow and pig dung (60:40) showed 10 % increase in methane production as investigated by Li et al (2014). Use of potato pulp and cow manure in the ratio of 20:80 also produced fair amount of methane in comparison to pure cow dung (Sanaei-Moghadam et al 2014). Besides this, there are reports on comparative studies for biogas production where various feedstocks such as kitchen waste, corn waste and spent tea waste have been used along with cow dung in a ratio of 1:1 producing less average biogas after 25-30 days; however, cow dung alone produced approximately 50 % more biogas than these mixtures (Munda et al 2012), thereby suggesting that other organic sources may produce biogas but cow dung still remains a potential source.…”

Anaerobic co-digestion of swine manure with sweet potato or cassava in different C/N ratios

“…The best results in both studies were obtained in proportions of 60:40 (pulp:SM), with C/N ratios of 33/1 and 95.6/1, resulting in increases of 25% and 41% in the specific CH 4 production, respectively. In the AcoD of cattle manure (CM) and potato pulp, SANAEI-MOGHADAM et al (2014) reported higher efficiency for a proportion of 20:80 (pulp:CM; C/N 15.5/1), which exhibited an increase of 137% in the specific production of CH 4 compared to the value of 147 L N .kg VSadded -1 reported in the monodigestion of cattle manure (C/N 11.7/1).…”

“…The AcoD of cattle manure with residues (peels) of potato was evaluated by SANAEI-MOGHADAM et al (2014) in semi-continuous feeding biodigesters under mesophilic conditions (35-37 °C), an HRT of 50 days, 7% TS, and 10 minutes every half an hour of agitation. The concentration of CH 4 in biogas reported by the authors was 58.8% in manure under monodigestion and 62.1% in an 80:20 treatment.…”