Influence of solid–liquid separation strategy on biogas yield from a stratified swine production system

Abstract

As the fourth largest swine producer and exporter, Brazil has increased its participation in the global swine production market. Generally, these units concentrate a large number of animals and generate effluents that must be correctly managed to prevent environmental impacts, being anaerobic digestion is an interesting alternative for treating these effluents. The low-volatile solid concentration in the manure suggests the need for solid-liquid separation as a tool to improve the biogas generation capacity. This study aimed to determine the influence of simplified and inexpensive solid-liquid separation strategies (screening and settling) and the different manures produced during each swine production phase (gestating and farrowing sow houses, nursery houses and finishing houses) on biogas and methane yield. We collected samples in two gestating sow houses (GSH-a and GSH-b), two farrowing sow houses (FSH-a and FSH-b), a nursery house (NH) and a finishing house (FH). Biochemical methane potential (BMP) tests were performed according to international standard procedures. The settled sludge fraction comprised 20-30% of the raw manure volume, which comprises 40-60% of the total methane yield. The methane potential of the settled sludge fraction was approximately two times higher than the methane potential of the supernatant fraction. The biogas yield differed among the raw manures from different swine production phases (GSH-a 326.4 and GSH-b 577.1; FSH-a 860.1 and FSH-b 479.2; NH -970.2; FH 474.5 NmLbiogas.gVS(-1)). The differences were relative to the production phase (feed type and feeding techniques) and the management of the effluent inside the facilities (water management). Brazilian swine production has increased his participation in the global market, been the fourth producer and the fourth exporter. The segregation of swine production in multiple sites has increased its importance, due to the possibilities to have more specialized units. Generally, these units concentrate a large number of animals and generate effluents that must be correctly managed to avoid environmental impact. Due to the biodegradability of manure, anaerobic digestion is an interesting alternative to treat these effluents. The low volatile solid concentration in the swine manure suggests the need for solid-liquid separation as a tool to improve biogas generation capacity. The present study aimed to determine the influence of simplified and cheap solid-liquid separation strategies (based on screening and settling) and different manure of each swine production phases (gestating and farrowing sows houses, nursery houses and finishing houses) on biogas and methane yield. We collected samples in two gestating sows house (GSH-a and GSH-b), two farrowing sows house (FSH-a and FSH-b), a nursery house (NH) and a finishing house (FH). The Biochemical Methane Production (BMP) tests were performed according to international standard procedure (VDI 4630). The settled sludge fraction responds for 20-30% of raw manure volume, producing 40-60% of the to...

Biogas Yield and Productiveness of Swine Manure for Different Reactor Configurations

“…The biogas was collected using gas-tight bag samplers (plastic/aluminum foil, Hermann Nawrot AG), and the methane content was analyzed using a portable infrared analyzer (Biogas 5000, Landtec). The biogas volume was then normalized to the standard temperature and pressure, i.e., 0 ºC and 1013 hPa, respectively (Steinmetz et al, 2016).…”

“…The CSTR startup was performed using 20% (v.v −1 ) of inoculum prepared by mixing three equal volumes of samples collected sludge from a UASB treating SM, sludge from a UASB reactor treating gelatin manufactory effluent, and fresh dairy cattle manure (Steinmetz et al, 2016). The UASB startup was performed with 20% (v.v −1 ) of the inoculum obtained from a UASB that treats effluents from a gelatin manufactory.…”

“…The production of biogas from the separation of the solid-liquid fraction of SM at different stages of production was studied by Amaral et al (2016). They observed that the supernatant fraction obtained the highest BY, with values between 0.4 and 1.2 LN biogas gVS add −1 and a methane content between 50% and 65%.…”

Improving the Anaerobic Digestion of Swine Manure through an Optimized Ammonia Treatment: Process Performance, Digestate and Techno-Economic Aspects

“…The swine manure used in the experiments was collected from Hashøj biogas plant (Sjaeland, Denmark) and was stored in closed containers at −20 • C until used. The manure collected originated from different local pig farms, thus containing manure from swine production at different stages, as classified in Cestonaro do Amaral et al [16]. The swine manure fibers were separated in farm from raw swine manure by means of a mobile decanter centrifuge and transported to Limfjordens Bioenergi (Mors, Denmark), where they were collected.…”

Evaluación de los co-beneficios ambientales y económicos del aprovechamiento energético de las excretas porcinas

“…En la literatura se reporta que las lagunas anaerobias soportan menores cargas a las utilizadas en reactores, se reportan cargas para las lagunas entre 0.04 a 0.05 kg SVT/ m 3 .dia comparado con digestores mesofílicos con cargas entre 1.77-2.48 kg SVT/ m 3 .dia (Safley y Westerman, 1988). Amaral et al (2016), reportan para este tipo de sistemas cargas orgánicas de aproximadamente 0.5 kg SVT/m 3 .día con TRH mayores a 30 días y concentraciones de sólidos totales menores al 3%. Con base en la comparación, el proceso de degradación anaerobia de las excretas de cerdo en la Granja se encuentra en condiciones similares a las reportadas en lagunas anaerobias y otros biodigestores de menor tamaño.…”