Pilot Plant for the Capture of Ammonia from the Atmosphere of Pig and Poultry Farms Using Gas-Permeable Membrane Technology

Abstract

Gas-permeable membrane (GPM) technology is a possible solution to reduce ammonia (NH3) emissions from livestock housing. This paper presents the results obtained with an NH3-capture prototype based on the use of expanded polytetrafluoroethylene (ePTFE) membranes in real conditions in a gestating sow house and a free-range laying hen house, comparing them with the results obtained in controlled laboratory conditions for the same type of waste. The NH3 present in the air of the livestock housing was captured by reaction with an acidic solution flowing inside the membranes. The periods of continuous operation of the pilot plant were 232 days at the pig farm and 256 days at the poultry farm. The NH3 recovery rate at the end of those periods was 2.3 and 0.4 g TAN·m−2·d−1 in the pig and the poultry farms, respectively. The limiting factor for the capture process was the NH3 concentration in the air, with the highest recovery occurring in the most concentrated atmosphere. Differences in NH3 capture were observed between seasons and farms, with capture efficiencies of 1.62 and 0.33 g·m−2·d−1 in summer and 3.85 and 1.20 g·m−2·d−1 in winter for pig and poultry farms, respectively. The observed differences were mainly due to the higher ventilation frequency in the summer months, which resulted in a lower NH3 concentration inside the houses compared to the winter months. This is especially important when considering the real applicability of this technology. The results obtained suggest that GPM technology holds promise for limiting NH3 emissions from livestock housing with NH3 ambient concentrations close to 20 ppm or as part of manure storage facilities, given that it allows for recovery of nitrogen in a stable and concentrated solution, which can be used as a fertilizer.

Evaluation of Different Capture Solutions for Ammonia Recovery in Suspended Gas Permeable Membrane Systems

“…In the case of weak organic acids, the conductivity remained stable or increased, as their starting conductivity is low and that of the formed salts is higher. The accumulation of NH 3 -N in the capture solutions followed a linear trend at both temperatures, with R 2 values above 0.93 and 0.91 at 25 and 2 • C, respectively, consistent with the behavior observed in other studies for sulfuric acid-based trapping solutions conducted over 14-day and 240-day periods [26,36].…”

“…Laboratory and pilot-scale studies have demonstrated the suitability of GPM technology based on expanded polytetrafluoroethylene (e-PTFE) membranes for N recovery from liquid effluents [16,21], wastewater from food industries [22], or sewage sludge [23]. Promising results have also been reported for the capture of NH 3 volatilized from animal manures [24][25][26].…”

Mitigation Strategies of Air Pollutants for Mechanical Ventilated Livestock and Poultry Housing—A Review

“…However, the high filtration efficiency and low-pressure drop in current dry filters cannot be simultaneously satisfied, and the filtration effect on air pollutants in livestock houses, such as NH 3 , is low. Some promising technologies present possible solutions to reduce NH 3 emissions from livestock housing, such as gas-permeable membranes (GPMs) and electrostatic spinning technology (EST) [19]. Specifically, the NH 3 in the house is captured by reaction with an acidic solution flowing inside the membranes prepared by GPM [19].…”

“…Some promising technologies present possible solutions to reduce NH 3 emissions from livestock housing, such as gas-permeable membranes (GPMs) and electrostatic spinning technology (EST) [19]. Specifically, the NH 3 in the house is captured by reaction with an acidic solution flowing inside the membranes prepared by GPM [19]. Membranes prepared by EST (Table 10) have also proven effective at filtering PM; toxic and harmful gases; and bacteria and viruses.…”

“…The efficacies of many of the currently BAT-listed options are both modest and difficult to regulate, and this list is still far from complete. Limiting emissions via the application of BATs alone may be insufficient to meet environmental goals; meanwhile, many other methods and treatment options are currently excluded [3,19]. Maurer et al [18] established a literature database tab on air management practices and tools, providing an overview of the mitigation practices best suited to addressing the emissions of odor, gas, and PM from livestock operations.…”