Anaerobic Digestion and Biogas Production: Combine Effluent Treatment with Energy Generation in UASB Reactor as Biorefinery Annex

Abstract

The issue of residues and industrial effluents represents an unprecedented environmental challenge in terms of recovery, storage, and treatment. This work discusses the perspectives of treating effluents through anaerobic digestion as well as reporting the experience of using an upflow anaerobic sludge blanket (UASB) reactor as biorefinery annex in a pulp and paper industrial plant to be burned in the boilers. The performance of the reactors has shown to be stable under considerable variations in load and showed a significant potential in terms of biogas production. The reactors UASB treated 3600.00 m3of effluent daily from a production of 150.00 tons. The biogas generation was 234.000 kg/year/mill, equivalent in combustible oil. The results of methane gas generated by the anaerobic system UASB (8846.00 kcal/m3) dislocate the equivalent of 650.0 kg of combustible oil (10000.00 kcal/kg) per day (or 234.000 kg/year). The production of 8846.00 Kcal/m3of energy from biogas can make a run at industrial plant for 2 hours. This substitution can save US$ 128.700 annually (or US$ 550.0 of fuel oil/tons). The companies are invested in the use of the biogas in diesel stationary motors cycle that feed the boilers with water in case of storage electricity.

An overview of physico-chemical mechanisms of biogas production by microbial communities: a step towards sustainable waste management

“…When this occurs, inhibitory products such as volatile fatty acids and H 2 accumulate in the reactor, slowing down the entire process. To overcome this, two-phase processes consisting of acidogenic and methanogenic fermentations have been investigated (Bowker 1983 ; Ke and Shi 2005 ; Xie et al 2012 ; Sharma et al 2012 ; Heeg et al 2014 ; Berni et al 2014 ) (Fig. 3 d).…”

“…When this system was applied in the treatment of alcohol distillery waste (COD = 10,000 mg/l) at HRTs of 16–72 h in the first phase, and 14 h in the second phase, 84 % COD removal and 92 % BOD removal were accomplished. A two-phase system consisting of a UAFP for the first phase and a horizontal AFP for the second phase has also been proposed, with which it should be possible to treat sewage waste water (COD 800–2600 mg/l) at HRTs of 2–5.5 h with a high methane content (~90 %) (Berni et al 2014 ).…”

Mass conversion pathway during anaerobic digestion of wheat straw

“…8, which was due to the relatively high hydrolysis acidication and methanogenesis rates. 31 Correspondingly, the carbon element distribution in the gas phase showed increment during these stages. In the rst 24 days of AD, nitrogen element in the liquid phase uctuated between 36.53% and 57.73%.…”

The role of biogas solutions in sustainable biorefineries

“…In such discussions, AD may be viewed as one of many biofuel production options, but one which also leads to more efficient wastewater treatment operation. This increased efficiency can be achieved, for example, through wastewater recovery and system energy cost reduction (Berni et al, 2014;Sharma et al, 2015). There are of course cases where the biorefinery is nonprofitable but it seem to depend on what products are produced and what selling price is set on the products (Nitzsche et al, 2016).…”

“…Also, economic comparisons suggest that anaerobic treatments are preferable when there is the possibility for internal use of the gas produced, if soil conditions are poor for aerobic treatments, if the temperature of the substrate is high (meaning less cooling is required) or if there is a lack of land to implement aerated treatments (Rantala and Väänänen, 1985). Furthermore, waste treatment via AD also enables the production of soil conditioner or biofertiliser from digestate (Berni et al, 2014;González-García et al, 2011;Meyer and Edwards, 2014).…”