Faculty of Civil Engineering & Technology, Universiti Malaysia Perlis (UniMAP), 02600 Arau, Perlis, Malaysia.
Centre of Excellence for Water Research and Environmental Sustainability Growth (WAREG), Universiti Malaysia Perlis (UniMAP), 02600 Arau, Perlis, Malaysia.
Phys Chem Chem Phys. 2024 Jul 31;26(30):20409-20426. doi: 10.1039/d4cp01421a.
Research into the speciation of sulfur and hydrogen molecules produced through the complex process of thermophilic dark fermentation has been conducted. Detailed surface studies of solid-gas systems using real biogas (biohydrogen) streams have unveiled the mechanisms and specific interactions between these gases and the physicochemical properties of a zeolite as an adsorbent. These findings highlight the potential of zeolites to effectively capture and interact with these molecules. In this study, the hydrogen sulphide removal analysis was conducted using 0.8 g of the adsorbent and at various reaction temperatures (25-125 °C), a flow rate of 100 mL min, and an initial concentration of approximately 5000 ppm hydrogen sulphide. The reaction temperature has been observed to be an essential parameter of Zeolite Socony Mobil - 5 adsorption capacity. The optimum adsorption capacity attains a maximum value of 0.00890 mg g at an optimal temperature of 25 °C. The formation of sulphur species resulting from the hydrogen sulphide adsorption on the zeolite determines the kinetics, thermodynamics, and mass transfer behaviours of Zeolite Socony Mobil - 5 in hydrogen sulphide removal and Zeolite Socony Mobil - 5 is found to improve the quality of biohydrogen produced in thermophilic environments. Biohydrogen (raw gas) yield was enhanced from 2.48 mol H mol hexose consumed before adsorption to 2.59 mol H mol hexose consumed after adsorption at a temperature of 25 °C. The Avrami kinetic model was fitted for hydrogen sulphide removal on Zeolite Socony Mobil - 5. The process is explained well and fitted using the Temkin isotherm model and the investigation into thermodynamics reveals that the adsorption behaviour is exothermic and non-spontaneous. Furthermore, the gas molecule's freedom of movement becomes random. The adsorption phase is restricted by intra-particle diffusion followed by film diffusion during the transfer of hydrogen sulphide into the pores of Zeolite Socony Mobil - 5 prior to adsorption on its active sites. The utilisation of Zeolite Socony Mobil - 5 for hydrogen sulphide removal offers the benefit of reducing environmental contamination and exhibiting significant applications in industrial operations.
已经对通过嗜热暗发酵这一复杂过程产生的硫和氢分子的形态进行了研究。使用实际的沼气（生物氢）流对固-气系统进行了详细的表面研究，揭示了这些气体与沸石作为吸附剂的物理化学性质之间的机制和特定相互作用。这些发现突出了沸石有效捕获和相互作用这些分子的潜力。在这项研究中，使用 0.8 g 的吸附剂并在不同的反应温度（25-125°C）、100 mL min 的流速和大约 5000 ppm 硫化氢的初始浓度下进行了硫化氢去除分析。已经观察到反应温度是沸石 Socony Mobil-5 吸附能力的一个重要参数。在最佳温度 25°C 下，吸附容量达到最大值 0.00890 mg g。由于硫化氢在沸石上的吸附而形成的硫物种决定了沸石 Socony Mobil-5 在硫化氢去除中的动力学、热力学和质量传递行为，并且发现沸石 Socony Mobil-5 可以改善在嗜热环境中产生的生物氢的质量。在 25°C 时，吸附前生物氢（原料气）的产率为 2.48 mol H/mol 己糖，吸附后提高到 2.59 mol H/mol 己糖。采用 Avrami 动力学模型拟合了 Zeolite Socony Mobil-5 上的硫化氢去除过程。该过程得到了很好的解释，并采用 Temkin 等温模型进行了拟合，热力学研究表明吸附行为是放热和非自发的。此外，气体分子的自由运动变得随机。在吸附前，硫化氢通过内扩散进入沸石 Socony Mobil-5 的孔道，然后通过膜扩散进入沸石 Socony Mobil-5 的活性位，吸附阶段受到限制。使用 Zeolite Socony Mobil-5 去除硫化氢可以减少环境污染，并在工业操作中具有重要的应用。
