基于太阳能光伏电解的资源化再生脱硫碱渣研究

Atmospheric pollution caused by SO2 is grim. The wet flue gas desulphurization using Ca(OH)2 has many advantages, but the desulfurization sludge obtained is difficult to treat. In this study, solar photovoltaic cells are proposed as the power supply. And the ion exchange membranes separated three-compartment electrolytic cell is employed to regenerate sodium alkali FGD residue Na2SO3, and Na2SO4, in order to achieve the recycling of the desulfurization agent, while to produce green energy H2 simultaneously. The specific research topics include: (1) probing the ion migration through the exchange membrane, and reducing the electrode reaction over-potential to optimize the reactor voltage distribution, therefore to improve the efficiency of the electrolytic regeneration process. Firstly, the energy consumption could be effectively reduced by maintaining the low chemical valence of the migration ions; Then based on the Donnan equilibrium theory, with micro-pore structure and size analysis, the spatial structure of the membrane should be selected to improve the ion migration rate and to reduce the membrane voltage. Electrode kinetics behavior will also be explored to screen the proper metal oxide electrodes. (2) coordinating the non-steady-state characteristics of photovoltaic power with the electrochemical regeneration process. The electrochemical efficiency of the electrolysis process will be measured dynamically using the electrochemical impedance spectroscopy analysis. Furthermore, the process of self-optimizing technology and incremental conductance method should be taken into account to assure the desulfurization regeneration effect. Based on the above work, the optimized electrochemical regeneration technology using solar photovoltaic cells could be proposed with the balanced regeneration and reclamation efficiencies.

SO2导致的大气污染形势严峻。常用Ca(OH)2湿法脱硫具有诸多优点，但产生的大量淤渣难以处理。本研究拟以太阳能电池为电源、利用离子膜三室电解槽再生钠碱法脱硫渣Na2SO3、Na2SO4，以此实现脱硫剂的循环使用、同时制备绿色能源H2！ 研究内容包括：（1）探询离子通过交换膜的迁移、降低电极反应过电位等机制来优化电解电压分布、提高电化学效率。首先通过调节离子以低价态迁移来降低电化学能耗；然后在Donnan平衡理论的基础上，优选膜空间结构以提高离子迁移速率、降低膜电压；同时基于电极反应动力学行为与分析表征，筛选金属氧化物电极。（2）阐释光伏电源的非稳态特性与电化学过程的协调机制。拟采用电化学阻抗谱技术分析电解过程中的电化学效率动态信息，并结合过程自寻优技术和电导增量法，来保障脱硫剂再生效果并兼顾资源化。在此基础上形成在多种条件下再生、资源化效率二者兼顾时的最优太阳能电解技术并建立合理评价体系

在本研究中，开发了一种太阳能膜电解反应器，可用于从脱硫废渣中有效再生钠碱脱硫剂（NaOH），再生的脱硫剂可以在前置脱硫工艺中循环利用；同时，通过该膜电解过程，硫元素以硫酸的形式得到了回收，并在反应器中产生氢气，收集后可作为清洁能源加以利用。.本文建立了三室膜电解反应器再生钠碱脱硫渣的数学模型。模拟结果表明，所有的解析解均与数值解之间具有较好的一致性，两组数据之间的相关系数均大于0.95。.通过引入无因次数，所建数学模型可以用于描述膜电解反应器的物料平衡。数值模拟结果表明，所有的模拟结果与实验数据之间具有较好的相关性，进一步证明了所建模型的有效性。.在上述理论与实验研究的基础上，从数值模拟结果中可以得到膜电解反应器的最佳运行参数，并经实验数据验证后发现：在最佳操作参数条件下，钠碱脱硫剂的再生电流效率可达84%，制备硫酸的电流效率达到87%，这些结果均可与氯碱工业的电流效率相媲美。此外，制氢的平均电流效率最高可达92.32%，且氢转化效率为38.90%，十分接近同样条件下41.43%的理论值。