摘要
沼气深度脱硫对于以沼气为制氢原料的分布式燃料电池电站十分重要。采用浸渍法制备了Zn O/γ-Al2O3、Cu O/γ-Al2O3及Cu/γ-Al2O3,实验研究了上述金属氧化物脱硫剂以及商业Fe2O3脱硫剂对沼气中羰基硫（COS）的深度脱除性能。结果表明,Cu基脱硫剂对COS的脱除性能优于Zn O/γ-Al2O3和Fe2O3,其可在250~400℃的温度下将COS脱除到10 ppb以下,能够满足分布式PEMFC电站对脱硫的要求,并达到在其沼气重整器的原料气体预热段完成深度脱硫的目标。Cu O/γ-Al2O3的硫容在250℃达到了最大的0.185 mmol·g^1。对Cu O/γ-Al2O3的脱硫机理进行了分析。固相产物中Cu S的存在说明了COS在Cu O/γ-Al2O3上的吸附为化学吸附,而Cu2O和Cu的存在则说明了沼气中的CH4与CO2在250℃以上的温度下发生了重整反应,Cu2O和Cu为该反应生成的H2和CO的还原产物。气相产物中检测到的H2S,可能是由COS的加氢反应生成的。还考察了沼气中水分对COS深度脱除的影响。Cu基脱硫剂的性能会受到水分的不利影响,但随着温度的升高,该影响呈减小的趋势。
For a distributed FC power station using biogas as the resource to produce hydrogen, deep desulfurization of biogas is important. Zn O/γ-Al2O3, Cu O/γ-Al2O3 and Cu/γ-Al2O3 were prepared via impregnation and deep removal of carbonyl sulfide（COS） from biogas with the above metal oxides were studied. At the same time, the commercial Fe2O3 desulfurizer was used as a reference. The results show that Cu-based desulfurizers are better than Zn O/γ-Al2O3 and Fe2O3 in desulfurization. Cu-based desulfurizers decrease COS to less than 10 ppb at 250~400℃, which meets the desulphurization requirement for distributed PEMFC power station and can achieve the goal of complete desulfurization within the feed preheating section of biogas reformer. Cu O/γ-Al2O3 has the highest sulfur capacity of 0.185 mmol？g？1 at 250℃. Mechanism of COS removal with Cu O/γ-Al2O3 was investigated. The presence of Cu S in solid product indicates that the adsorption of COS on Cu O/γ-Al2O3 is via chemical adsorption. The existence of Cu2 O and Cu means that CH4 and CO2 reacts at above 250℃, as Cu2 O and Cu are the reduction products of H2 and CO which are generated in the reforming reaction. H2 S is detected in the gas product, which may be generated by the hydrogenation reaction of COS. In addition, moisture in biogas has an adverse effect on the desulfurization performance of Cu-based desulfurizers, which can be depressed by increasing temperature.
出处
《高校化学工程学报》
EI
CAS
CSCD
北大核心
2015年第2期443-451,共9页
Journal of Chemical Engineering of Chinese Universities
基金
国家自然科学基金(20776016)
国家自然科学基金(21006005)
