A key strategy allied with today is to develop an alternative energy source instead of fossil fuels in order to compensate present energy need in addition to reduce environmental concerns owed by pollution and global warming. Energy generation in feasible manner without possessing environmental crash is a difficult task where alternative concepts were requisite to ensure sustainable development with accessible technologies. Further advances triggered renewed attention in biogas production technology while it has great impacts on diminishing major economic issues raised in the world. Since the light of these strategies, the present review intended to critically evaluate the recent technological advances and promising prospects coupled with various aspects of biogas production such as sustainable feedstock utilization, microbial and enzyme dynamics, parameter optimization and process segregation, for enhancing this technology in outlook. Appropriate selection, co-digestion, and biotransformation offers a great challenge that crafts substrate to become more energy efficient, besides to trim down the constraints behind principle biomass utilization. A basic framework for process stimulation with microorganisms and enzyme preparations explored that further experimental trials by means of identification of efficient microbes and standardization of enzyme dynamics would augment the feasibility of energy flow during anaerobic digestion. Accordingly, the optimization of various parameters is preferred to accelerate biogas production by resolving the problems occur during anaerobic digestion. Despite the development of multi-stage digester designs intend a breakthrough for process segregation and existing opportunities in this aspect needed further research interest to attain better performance of the system. Moreover, advance simulation approaches using projected prospects from this review would realize significant enhancement of biogas production in the predictable manner.

A review on current aspects and diverse prospects for enhancing biogas production in sustainable means.

Yusuf M.O.L., Debora A., Ogheneruona D.E. , 2011. Ambient temperature kinetic assessment of biogas production from co-digestion of horse and cow dung . Res. Agr. Eng., 57: 97–104. Biogas production from 5 batch digesters containing varying ratio of mix of horse and cow dung was studied for a period of 30 days at ambient temperature. It was observed that biogas production was optimized when horse and cow dung were mixed in a ratio of 3:1. The modified Gompertz equation was used to adequately describe the cumulative biogas production from these digesters. In addition, a modified first order model was developed to assess the kinetics of the biodegradation process. It was observed that the rates of substrate biodegradability and of removal of the biodegradable fractions of the substrate could be obtained by plotting 1/ t (ln( dyt/dt)) against the inverse of time of digestion. This modified first order model also showed that the digester containing horse dung and cow dung in the ratio of 3:1 had the highest short term anaerobic biodegradability index (STABI) of 3.96 at room temperature.

/pdf/ambient-temperature-kinetic-assessment-of-biogas-production-m8ptcvytyv.pdf

Ambient temperature kinetic assessment of biogas production from co-digestion of horse and cow dung

The co-digestion of cow dung with rice husk for biogas production at laboratory scale was the subject of this investigation. The study was carried out at room temperature that is, 26 - 29°C for a period of 52 days with a total solid concentration of 8% in each sample (fermentation slurry). The biogas produced was collected by water displacement method which was subsequently measured. Sample A (50 wt % cow dung, 50 wt % rice husk) showed a cumulative biogas production of 161.5 ml at the end of the 38th day of the experiment after which there was no further production. The production from sample B (25 wt % cow dung, 75 wt % rice husk) was not significant, while there was no production from sample C(0 wt % cow dung, 100 wt % rice husk).

	 

	Key words: Biogas, cow dung, rice husk, co-digestion.

https://www.academicjournals.org/article/article1380534390_Iyagba et al.pdf

The study of cow dung as co-substrate with rice husk in biogas production

The present paper describes the application of three-tier vermiculture biotechnology coupled with vermi-filtration to convert secondary liquid effluents from a gelatine manufacturing unit into ‘bio-safe’ clean water. The experiments were conducted at a pilot scale. The protocol involved pretreatment of selected effluents using a combination of protease and cellulase. Later, mixed cultures of Aspergillus flavus (BRC - 27), A. niger (BRC - 28), Nitrobacter winogradskyi (BRC - 5), Spirulina platensis (BRC - 45), Oscillatoria princeps (BRC - 46) and Chlorella vulgaris (BRC - 47) were inoculated. The effluents were then passed through a series of 3 vermi-filter (VF) tanks, the uppermost layer of each consisting of bedding material inoculated with selected enzymes, microorganisms and colonies of Lumbricus rubellus that served as biofilters followed by a trickling filter system. The final vermi-filtered water exhibited a significant decrease in COD by 90.08 ± 0.176%, and BOD by 89.24 ± 0.544%. In 3 months, the total CFU in the upper bedding layer of specific VF tanks exhibited an exponential increase indicating expected degradation potential of the organic matter in the effluents. The bedding material gradually converted into humified vermicompost on which seedlings of Canna indica were planted. The final vermi-filtered discharge was clean and its bio-safety was evaluated by using it for secondary purposes, irrigation and Spirulina cultivation.

/pdf/application-of-vermi-filter-based-effluent-treatment-plant-2bhlwqqry1.pdf

Application of vermi-filter-based effluent treatment plant (pilot scale) for biomanagement of liquid effluents from the gelatine industry.

Overall measurement of methanogenic activity of sludge and or slurry is thought as a key for understanding the basic physiology of anaerobic consortia involved in anaerobic digestion process of an alternative biomass. In this study, the methanogenic activity of biogas plant slurry was used to evaluate the anaerobic digestion of ossein factory wastes such as sinews and primary clarified bone waste (PCBW) and cyanobacterial biomass in standard assay conditions. A maximum methanogenic activity was reported here when ossein factory wastes mixed with cyanobacterial biomass in specific proportions in which sinews and PCBW alone also favored to a significant methane yield. Cyanobacterial biomass alone did not give a desirable methanogenic activity. Approximately 48% of total solids were destroyed from these wastes after 30 days. This study gives information on the use of these wastes with suitable proportions for taking an effort in a large-scale anaerobic digestion in an effective way of ossein factory.

Evaluation of methanogenic activity of biogas plant slurry for monitoring codigestion of ossein factory wastes and cyanobacterial biomass.

Sinews is a pasty proteinaceous by-product discharged from a primary bone clarification tank in the ossein industry, which was mixed with cattle dung in different proportions at ambient temperature. This study found that a mixture of sinews (40%) and cattle dung (60%) was more appropriate for enhanced methane yields with a high efficacy on anaerobic degradation. A maximum cumulative biogas production volume (18 L) with 71-77% methane content was obtained even with more parts of the sinews were used as a substrate. The best biogas production yield was 23.4 L biogas/Kg TVS added, revealed the suitability of the sinews mixture (40%) in the biomethanation process. In addition, the pH of each digester was not shifted to alkaline which was constantly maintained within optimal range during the course of digestion. Perhaps, this alternate strategy will be helpful for managing the odor produced from sinews during bulk storage.

A preliminary study on co-digestion of ossein industry waste for methane production

Electronic structure, magnetic and thermodynamic properties of yttrium based half Heusler alloys YXZ (X = Fe, Co, Cr; Z = As, Sb): A first principles study

Prabaharan Dharmaraj

Papers

A preliminary study on co-digestion of ossein industry waste for methane production

Electronic structure, magnetic and thermodynamic properties of yttrium based half Heusler alloys YXZ (X = Fe, Co, Cr; Z = As, Sb): A first principles study