Abstract In this work, a stoichiometry-driven heuristic feedforward control strategy is proposed for controlling the oxygen supply to a biological gas desulfurization process that treats biogas, landfill, and high-pressure natural gas containing H2S and volatile organic sulfur compounds (VOSC). Traditionally, PI or PID feedback control is used when the feed gas contains H 2 S only. Because the oxidation–reduction potential (ORP) is mostly dominated by the dissolved sulfide concentration, the feedback controller maintains a constant sulfide concentration in the bioreactor by maintaining an ORP setpoint value through controlling the oxygen supply. However, when the feed gas also contains VOSCs, e.g., thiols, it appears from our research that controlling ORP at a fixed value does not lead to stable process performance. Hence, an alternative control strategy is proposed, which controls the O 2 /H 2 S supply ratio based on the stoichiometry of the dominant chemical reaction and experimental experience. The heuristic feedforward control strategy was validated by a fluctuating supply of H 2 S (26.5 to 126.5 mM S day−1) in the absence and presence of ethanethiol (0.8 to 1.16 mM S day−1). A sulfur selectivity above 95 mol%, and complete removal of H 2 S, was achieved at an O 2 /H 2 S supply ratio of about 0.63 mol mol−1 compared to 56 mol% when a PI/PID controller was used at a randomly varying, stepwise H2S dosing rate This work shows that fluctuations in the H 2 S loading rate and presence of ethanethiol in the feed gas of full-scale systems can be controlled by applying the heuristic feedforward control strategy. However, online measurements of the H2S concentration in the feed gas are required to implement the proposed strategy in full-scale installations successfully.

中文翻译：

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化学计量驱动的启发式前馈控制生物气体脱硫过程中的供氧

摘要 在这项工作中，提出了一种化学计量驱动的启发式前馈控制策略，用于控制生物气脱硫过程的氧气供应，该过程处理沼气、垃圾填埋场和含有 H2S 和挥发性有机硫化合物 (VOSC) 的高压天然气。传统上，当原料气仅包含 H 2 S 时，使用 PI 或 PID 反馈控制。由于氧化还原电位 (ORP) 主要由溶解的硫化物浓度决定，反馈控制器通过控制氧气供应来维持 ORP 设定值，从而维持生物反应器中恒定的硫化物浓度。然而，当原料气还包含 VOSCs，例如硫醇时，从我们的研究看来，将 ORP 控制在固定值不会导致稳定的工艺性能。因此，提出了一种替代控制策略，该策略基于主要化学反应的化学计量和实验经验来控制 O 2 /H 2 S 供应比。在乙硫醇不存在和存在（0.8 到 1.16 mM S day-1）的情况下，启发式前馈控制策略通过 H 2 S 的波动供应（26.5 到 126.5 mM S day-1）进行验证。在 O 2 /H 2 S 供应比约为 0.63 mol mol-1 时实现了高于 95 mol% 的硫选择性和完全去除 H 2 S，相比之下，当 PI/PID 控制器用于随机变化的逐步 H2S 加药率 这项工作表明，可以通过应用启发式前馈控制策略来控制 H 2 S 加载率的波动和全规模系统原料气中乙硫醇的存在。然而，