Development and testing of surface-based and water-based-diffusion kinetic models for studying hydrolysis and biogas production from cow manure

Abstract

25The hydrolytic step is usually considered the rate limiting step in the biological conversion of 26 ligno-cellulose material into biofuels. Current optimization approach attempts to understand the 27 mechanism of hydrolysis in order to boost biogas production. In this study, the development and 28 testing of a surface-based and a water-based-diffusion kinetic model for modeling biogas 29 production from cow manure was conducted at ambient conditions using total solid (TS) loading maximum initial water uptake rate (k 0 2 ) (1.86E-05 m 3 /kg/day) was observed at 9% (TS) with a 39 simultaneous minimization in the rate of fragmentation (0.13/day). For optimal production of 40 biofuels from ligno-cellulose material, appropriate quantity of C 1 -factor in cellulase, the degree 41 of crystallinity and particle size may be critical for efficient biomass conversion.

Time-Lag Models for Continuous Stirred Tank and Plug Flow Digesters for Biogas Production

“…This feature can be seen in the data taken by Mondal on the production of biogas by AD of vegetable wastes in a semicontinuous flow compartmental digester (to be discussed later) and also in the data presented by Jayalakshmi et al on solid-phase AD of kitchen waste in an inclined plug flow digester. The experimental cumulative biogas or methane yield as a function of retention time in batch AD also exhibits such a characteristic. ,, This S-shaped character of the biogas production rate curve can be captured by the time-lag models as will be shown later. The time-lag models presented herein have only three parameters, which can be easily estimated.…”

“…For design, scale-up, and control of the AD process, theoretical models of the process are essential. There is a considerable literature on theoretical modeling of AD, some examples of which are the works of Husain, Massé and Droste, Lokshina et al, and Momoh and Saroj . Many models exist which attempt to relate microbial growth, substrate depletion, and biogas generation.…”

“…Moreover, in the case of lingo-cellulosic biomass, there will be complicating factors like mass-transfer limitations, fragmentation, and breakage of biomass particles with progress of AD, etc., which will make the theoretical analysis of AD of such biomass exceedingly complex. In this regard, we note that Momoh and Saroj have very recently presented surface-based and water-based-diffusion kinetic models, which attempt to incorporate some of these effects, for correlating experimental data on biogas production from cow manure in batch AD. However, these models contain 4–6 parameters, which have to be obtained by nonlinear regression.…”

Development of a novel fractal-like kinetic model for elucidating the effect of particle size on the mechanism of hydrolysis and biogas yield from ligno-cellulosic biomass

“…(20), where Y exp and Y pred are experimental and predicted biogas yield; n represents the number of data points; p represents the number of parameter of the models. Usually, the model that that gives the lowest AIC c value is automatically considered the best between two compared models because it is believed to be closer to the unknown truth and would lead to less information loss relative to the alternative model (Momoh and Saroj, 2016). However, further insight into the model comparison can be explained using the with AIC i has considerable less support while, i ∆ greater than indicates that the model with AIC i is very unlikely to provide support when compared to the model with AIC min.…”

Methane Enhancement through Sequential Thermochemical and Sonication Pretreatment for Corn Stover with Anaerobic Sludge

“…Anaerobic digestion (AD) is a widely adopted waste treatment technology on the commercial scale that finally produces biogas, consisting of 50–70% methane with a large reduction in sludge volume. , Anaerobic digestion is not only a useful method for renewable energy production, but it also proved helpful to reduce the risk of environmental pollution and greenhouse gas emissions. − It consisted of four steps: hydrolysis, acidogenesis, acetogenesis, and methanogenesis, − and in the case of lignocellulosic fed material to anaerobic digestion, hydrolysis is considered as the rate limiting stage during the anaerobic digestion process. ,− During the hydrolysis stage, the transformation of complex macromolecular structure of plant tissues could take place to easily digestible products like peptides, amino acids, alcohols, proteins, and fatty acids. However, there are some drawbacks of using corn stover as direct AD feed material on commercial scale, because they resulted in poor anaerobic digestion efficiencies with less volatile solids reduction and methane production. , The phenomena could be well emphasized that the corn stover contains high contents of lignin and complex hemicellulosic texture that retarded the hydrolysis stage of the AD process. ,, …”