Influence of Surface Characteristics of Palm Shell Activated Carbon Modified with Nanostructured Nickel for Reactive Adsorption of Hydrogen Sulfide

Abstract

Hydrogen sulfide (H2S) is a colorless and toxic gas that could harm people and the environment. Due to its acidic and toxic properties, H2S cannot be burnt directly, hence it is necessary to remove it. The aim of this work is to study the influence of surface characteristics of modified palm shell activated carbon (PSAC) with Nickel nanoparticles (Ni nps) towards H2S removal. Surface characteristics consist of a combination of various analyses on the adsorbent’s surface such as surface morphology, surface area, surface porosity, and surface functional groups. The Ni nps were synthesized by using the alkaline precipitation method at different synthesis parameters; pH (8 – 10), precipitant molarity (6.5M – 7.5M), and temperature (55◦C – 65◦C). To study the adsorption of H2S, the PSAC adsorbent was modified with the synthesized Ni nps at 400◦C for 3 hours. The performance of modified Ni nps with PSAC (Ni-PSAC) adsorbents was tested in a custom-design H2S scrubber for H2S removal application. The surface characteristics of the modified Ni-PSAC adsorbent were analyzed by using TGA, TEM, SEM, and FTIR. Among the impregnated adsorbents, Ni-PSAC with pH 10, 6.5 M of precipitant molarity, and temperature of 65◦C gives the highest adsorption capacity (9.60 mg H2S/g Ni-PSAC) and breakthrough time (14 minutes) compared to the rest of the adsorbents. The introduction of Ni nps in the PSAC adsorbent structures resulted in better H2S removal compared to the unimpregnated PSAC adsorbent. The existence of Ni nps helps to increase the availability of oxygen vacancies in the adsorbent with the aid of nanostructured added in the adsorbent.

Keywords

• nickel nanoparticles
• adsorption
• hydrogen sulfide
• activated carbon
• surface characteristics