Pilot-Scale H2S and Swine Odor Removal System Using Commercially Available Biochar

Abstract

Although biochars made in laboratory seem to remove H2S and odorous compounds effectively, very few studies are available for commercial biochars. This study evaluated the efficacy of a commercial biochar (CBC) for removing H2S and odorous volatile organic compounds (VOCs). We found that the well-known Ergun equation may not be adequate in predicting pressure drop for properly sizing a ventilation system. The H2S breakthrough adsorption capacity of the CBC was 2.51 mg/g under humid conditions, which was much higher than that for dry conditions. The breakthrough capacity increased with the influent concentration of H2S. The efficacy of a pilot-scale biochar odor removal system (PSBORS) for removing 15 odorous VOCs was evaluated by placing it in a swine gestation stall continually treating the inside air for 21 days. All VOCs in the PSBORS effluent were below detection limit except for acetic acid. However, due to the very high odor threshold of acetic acid, its contribution to the odor would be minimal. It appeared that the CBC could be used to reduce both H2S and odorous VOCs with the potential of recycling the spent CBC for soil health improvement after using it for H2S and odor removal.

Evaluation of Biogas Production from Swine Manure Using a UASB Reactor (Upflow Anaerobic Sludge Blanket) with Long-Term Operation

“…The H2S concentration in raw biogas ranges from 50 to 10,000 ppm, depending upon the feedstocks [29]. H2S is formed during the microbiological reduction of compounds that contain sulfur, and it can lead to corrosion problems, damage to biogas equipment, generators, combustion engines, and other metal components [30,31]. A concentration higher On the other hand, the rest of the components in the biogas were CO 2 , O 2 , N 2 , and H 2 S at 18.06%, 8.99%, 3.91%, and 1413 ppm, respectively, and according to the results obtained, the mean methane production yield was 507 mL CH 4 g VS −1 when the reactor operated with an HRT of 19 days and an OLR of 2.68 g VS L −1 d −1 .…”

“…The H 2 S concentration in raw biogas ranges from 50 to 10,000 ppm, depending upon the feedstocks [29]. H 2 S is formed during the microbiological reduction of compounds that contain sulfur, and it can lead to corrosion problems, damage to biogas equipment, generators, combustion engines, and other metal components [30,31]. A concentration higher than 500 ppm of H 2 S can cause unconsciousness and death in people; H 2 S content can be almost fully removed by several methods [32].…”

Biochar as a Sustainable Product for the Removal of Odor Emissions - Mini Literature Review

“…Initial pilot scale results confirm that most of the VOCs were below the detection limit (except for acetic acid) following the use of biochar in the swine gestation barn. The authors also determined that the adsorption capacity of H2S by commercial biochar is high, and in addition, after the odor removal process, it can be recycled to improve the soil condition [58]. Kumar et al [59] focused on the adsorption of 6 different VOCs (benzene, toluene, methyl chloride, xylene, chloroform, carbon tetrachloride) by unactivated biochars made of neem, sugarcane, and bamboo feedstock's at temperatures of 350 -550 o C showed that process temperature variability and the type of raw material significantly influences the change of porosity and specific surface of biochar.…”

The influencing mechanism of O2, H2O, and CO2 on the H2S removal of food waste digestate-derived biochar with abundant minerals

“…Hydrogen sulfide (H 2 S) is an odorous and toxic gas emitted from various industries. It is corrosive to pipeline equipment during biogas utilization (Li et al 2020) and can cause acute and chronic health problems if directly emitted into the environment (Ro et al 2021). Besides, the odor threshold of H 2 S is within a very low range of 0.008-0.13 ppm (NRC 2010), making the H 2 S removal very desirable even when it is at low concentrations.…”