(755e) Gas Storage in Superactivated Hydrochars Synthesized from Anaerobic Digested Food Waste
AIChE Annual Meeting
2020
2020 Virtual AIChE Annual Meeting
Environmental Division
Fundamentals and Applications for Municipal Solid Waste Treatment and Valorization
Friday, November 20, 2020 - 9:00am to 9:15am
In the recent past, various efforts have been undertaken to store CO2 and H2 in metal-organic frameworks (MOFs), covalent organic frameworks (COFs) etc. due to their large specific surface area, small pore size, and large pore volume. However, it is not economically feasible to store bulk amounts of CO2 and H2 in MOFs or COFs, as they could be cost intensive. Hence, researchers have been focusing on producing storage material from waste material such as food waste, sewage sludge, etc. Anaerobically digested food waste could be a very low-cost feedstock to synthesize gas storage materials. The objective of this study was to produce superactivated hydrochars from food waste digestate for storing H2 and CO2. Hydrochar from food waste digestate was produced at 220 and 260 °C and activated using KOH in two methods. Produced hydrochars were chemically activated at 3 different temperatures (600, 700, 800 °C) and 4 different ratios (2:1, 3:1, 4:1, 5:1). BET analysis was conducted of the activated chars to determine the specific surface area, pore type, and corresponding pore volume. In addition, High-Pressure Volumetric Analyzer (HPVA) was used to measure the volumetric uptake of H2 and CO2. Analyses showed that activation ratio is the most important factor to control the material properties. Thus, an optimum ratio (4:1) was identified to work best for storing both H2 and CO2. Although the storage capacity in superactivated hydrochar is still lower than the MOFs and COFs, further investigation is required to improve the storage capacity on these waste-derived materials.