龔 娟1, 焦以飛1, 蘇慶泉2, 米萬良
(1. 北京科技大學(xué)機(jī)械工程學(xué)院, 北京100083;2. 北京科技大學(xué)北京市高校節(jié)能與環(huán)保工程研究中心, 北京100083)

摘要：沼氣深度脫硫?qū)τ谝哉託鉃橹茪湓�料的分布式燃料電池電站十分重要。采用浸漬法制備了ZnO/γ-Al2O3、CuO/γ-Al2O3及Cu/γ-Al2O3，實(shí)驗(yàn)研究了上述金屬氧化物脫硫劑以及商業(yè)Fe2O3脫硫劑對沼氣中羰基硫(COS)的深度脫除性能。結(jié)果表明，Cu基脫硫劑對COS的脫除性能優(yōu)于ZnO/γ-Al2O3和Fe2O3，其可在250~400℃的溫度下將COS脫除到10 ppb以下，能夠滿足分布式PEMFC電站對脫硫的要求，并達(dá)到在其沼氣重整器的原料氣體預(yù)熱段完成深度脫硫的目標(biāo)。CuO/γ-Al2O3的硫容在250℃達(dá)到了最大的0.185 mmol⋅g−1。對CuO/γ-Al2O3的脫硫機(jī)理進(jìn)行了分析。固相產(chǎn)物中CuS的存在說明了COS在CuO/γ-Al2O3上的吸附為化學(xué)吸附，而Cu2O和Cu的存在則說明了沼氣中的CH4與CO2在250℃以上的溫度下發(fā)生了重整反應(yīng)，Cu2O和Cu為該反應(yīng)生成的H2和CO的還原產(chǎn)物。氣相產(chǎn)物中檢測到的H2S，可能是由COS的加氫反應(yīng)生成的。還考察了沼氣中水分對COS深度脫除的影響。Cu基脫硫劑的性能會(huì)受到水分的不利影響，但隨著溫度的升高，該影響呈減小的趨勢。
    關(guān)鍵詞：沼氣；羰基硫；金屬氧化物；深度脫硫；質(zhì)子交換膜燃料電池
    中圖分類號(hào)：S216.4 文獻(xiàn)標(biāo)識(shí)碼：A DOI：10.3969/j.issn.1003-9015.2015.02.031

Deep Removal of Carbonyl Sulfide in Biogas
    GONG Juan1, JIAO Yi-fei1, SU Qing-quan2, MI Wan-liang
    (1. School of Mechanical Engineering, University of Science and Technology Beijing,Beijing 100083, China; 2. Beijing Engineering Research Center for Energy Saving and Environmental Protection,University of Science and Technology Beijing, Beijing 100083, China)
    Abstract: For a distributed FC power station using biogas as the resource to produce hydrogen, deep desulfurization of biogas is important. ZnO/γ-Al2O3, CuO/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 ZnO/γ-Al2O3 and Fe2O3 in desulfurization. Cu-based desulfurizers decrease COS to lessthan 10 ppb at 250~400℃, which meets the desulphurization requirement for distributed PEMFC power station andcan achieve the goal of complete desulfurization within the feed preheating section of biogas reformer. CuO/γ-Al2O3has the highest sulfur capacity of 0.185 mmol⋅g−1 at 250℃. Mechanism of COS removal with CuO/γ-Al2O3 wasinvestigated. The presence of CuS in solid product indicates that the adsorption of COS on CuO/γ-Al2O3 is viachemical adsorption.The existence of Cu2O and Cu means that CH4 and CO2 reacts at above 250℃, as Cu2O and Cuare the reduction products of H2 and CO which are generated in the reforming reaction. H2S is detected in the gas product, which may be generated by the hydrogenation reaction of COS. In addition, moisture in biogas has an adverseeffect on the desulfurization performance of Cu-based desulfurizers, which can be depressed by increasing temperature.
    Key words: biogas; carbonyl sulfide; metal oxide; deep desulfurization; PEMFC 

1 前言
     沼氣是一種重要的可再生能源，近年來，作為分布式燃料電池電站的重整制氫原料受到了越來越多的關(guān)注[1~3]。沼氣的組成較復(fù)雜，通常為：40%~70% CH4、30%~50% CO2、0~20% N2、0~5% O2、0~4000 ppm H2S、0~100 ppm硫醇，還有微量的羰基硫(COS)等[4]。沼氣中的硫化物不僅會(huì)引起設(shè)備和管路的腐蝕，還會(huì)對重整制氫裝置中的催化劑以及燃料電池陽極催化劑等產(chǎn)生毒化作用[3]。因此，通常會(huì)在沼氣重整器的前段設(shè)置脫硫裝置，以對沼氣進(jìn)行脫硫

沼氣中羰基硫的深度脫除