Produção específica de biogás a partir de manipueira em reator de fase única

Abstract

RESUMO:O presente artigo mostra um estudo sobre a produção de biogás a partir de manipueira, considerando o volume de um reator de fluxo tubular horizontal de fase única. O objetivo do trabalho foi avaliar a produção de biogás aumentando-se as cargas orgânicas e os volumes de alimentação, o que resultou em redução do tempo de retenção hidráulica (TRH). O reator foi alimentado continuamente, com cargas orgânicas de 1,18; 1,28; 1,57 e 2,68 g DQO L -1 rd -1 (gramas de demanda química de oxigênio por litro de reator por dia) em TRHs de 15; 13,0; 8,3; 6,6 dias, respectivamente. As produções de biogás foram de 0,52; 0,41; 0,65 e 0,63 L L -1 rd -1 , destacando-se que o primeiro TRH avaliado foi o de 13 dias, seguido de 8,3; 6,6 e 15 dias. Do estudo, concluiu-se que, com a diminuição do TRH, ocorre maior produção de biogás por volume de reator. Consequentemente, através da utilização do TRH adequado, pode-se aproveitar melhor o volume do reator, fato que resultará em economia na implantação da tecnologia em indústrias processadoras de mandioca. PALAVRAS-CHAVE:água residuária, digestão anaeróbia, fecularia, mandioca, metano. SPECIFIC BIOGAS PRODUCTION FROM MANIPUEIRA AT ONE-PHASE REACTORABSTRACT: This article presents a study on biogas production from wastewater cassava considering the volume of a one-phase horizontal tubular flow reactor. The objective was to evaluate the biogas production, enlarging the organic loadings and feeding volums, resulting in minor hydraulic retention times (HRT). The reactor was continuously fed with organic charges corresponding to 1.18; 1.28; 1.57 and 2.68 g COD L -1 r d -1 (grams of oxygen chemical demand per liter of reactor per day), resulting in hydraulic retention times 15; 13; 8.3 and 6.6 days. The correspondent specific biogas productions were, respectively, 0.52; 0.41; 0.65 and 0.63 L L -1 rd -1 , emphasizing that the 13-day was the first HRT rated, followed by 8.3, 6.6 and 15 days. It was concluded that with the HRT decrease occurred larger biogas production per reactor volume. Therefore, with the correct selection for HRT, it is possible to make the best of the reactor volume, resulting in economy at the technology implantation in cassava starch industries.

Cassava starch extraction effluent treatment in a one phase tubular horizontal pilot reactor with support medium

“…Two other moderate linear correlations, but negative, occurred with the volumetric biogas production and ratio VA/TA. The researches confirm that the reduction of HRT increases the volumetric production of biogas, fact explainable by the increasing of the microbial metabolism in face of increased substrate supply (KUCZMAN et al, 2011). The content of volatile acids in the pilot reactor was another variable that increased with HRT reduction, possibly due to the increased flow of effluent in the reactor, with reduction of methanogenic activity (WIJEKOON et al, 2011).…”

“…Therefore, to increase the biogas production per reactor volume it should be operated with higher loads (KUCZMAN et al, 2011).…”

“…COD reductions occur with the increasing in the HRT, because the substrate has more time to degrade itself (FENG et al, 2008;KUCZMAN et al, 2013). KUCZMAN et al (2011) fed an horizontal tubular bench reactor with effluent of cassava starch, using an organic load of 2.68 g COD L -1 d -1 , TRH of 7 days and 33 °C, and obtaining a COD reduction of 95%. In the present experiment, they were obtained COD removal efficiencies of 70% for the same HRT (7 days) and an average temperature of 23.6 C. The advantage achieved by the authors may be explained by the operating temperature, higher in 9.4 °C, even without support mean.…”

“…The research of KUCZMAN et al (2011) In the Figure 9, it is observed that the HRT of 9.8 days is the treatment that combines both the higher reduction of COD with higher production of biogas by COD consumed. The smoothness of the curve defines a broad range of HRT, between 8.0 and 12.0 days, as the greatest performance in the variables reduction of COD and biogas production by COD consumed.…”

Optimization of Anaerobic Treatment of Cassava Processing Wastewater

“…The pH of the wastewater is 4.02, which is near the 4.37 found by KUCZMAN et al (2011); conversely, the concentration of total volatile solids was 5151 mg L -1 , being lower than the value found by the same authors (7510 mg L -1 ). The starch content of the wastewater is 3.20%, which is below the 6.3% found by SUMAN et al (2011).…”