The impact of sample preparation of the macroalgae Laminaria digitata on the production of the biofuels bioethanol and biomethane
The impact of sample preparation of the macroalgae Laminaria digitata on the production of the biofuels bioethanol and biomethane
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DOI：
10.1007/s10811-014-0368-5
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发表时间：
2015-04-01
影响因子：
3.3
通讯作者：
Gallagher, J. A.
中科院分区：
文献类型：
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作者：
Adams, J. M. M.;Schmidt, A.;Gallagher, J. A.
清洗大型藻类是一个“标准”的初始预处理步骤，在大量关于大型藻类生物燃料生产的论文中有报道。洗涤去除颗粒物;然而，在这项研究中，我们表明洗涤也可能对大型藻类中存在的水溶性碳水化合物含量产生不利影响，可能会减少生物燃料的产量。如果将大型藻类视为生物燃料和平台化学品的原料，这将产生重大影响。我们比较了来自夏季和冬季收获的洗涤和未洗涤的材料，这些材料随后通过以下三种方法干燥：（1）立即烘干，（2）冷冻，然后烘干和（3）冷冻干燥。评估了水溶性碳水化合物的比例，并且在洗涤的那些的海带多糖含量中观察到高达49.3%的降低。烘箱干燥也导致海带多糖的一些降解，与冷冻干燥相比，葡萄糖浓度增加约10倍。当这种材料被用作生物燃料生产的底物时，未洗涤的指状海带在所有不同干燥的夏季样品和三分之二的冬季样品中产生较高浓度的乙醇，这表明不洗涤是有利的，除非涉及其他因素，例如，大量的颗粒材料存在于大型藻类上。相比之下，在厌氧消化研究中使用的洗涤样品在三分之二的干燥处理中比未洗涤的样品产生更高的甲烷产率，这可能是由于厌氧微生物聚生体中的耐盐性较低，因此预洗涤步骤可以被认为更适合于这种转化途径。
Washing macroalgae is a 'standard' initial pre-treatment step, reported in a number of papers on biofuel production from macroalgae. Washing removes particulate matter; however, in this study, we show that washing may also have an adverse effect on the water-soluble carbohydrate contents present in the macroalgae, potentially reducing the quantity of the biofuel produced. This has major implications if macroalgae are to be considered as a feedstock for biofuel and platform chemicals. We compared washed and unwashed material from summer and winter harvests which were subsequently dried by three methods as follows: (1) immediate oven drying, (2) freezing, then oven drying and (3) freeze-drying. The proportions of the water-soluble carbohydrates were assessed and a decrease of up to 49.3 % seen in the laminarin content of those washed. Oven drying also resulted in some degradation of the laminarin with approximately 10x increase in glucose concentrations compared to freeze-drying. When this material was used as a substrate for biofuel production, unwashed Laminaria digitata generated a higher concentration of ethanol in all the differently dried summer samples and two thirds of winter samples, suggesting that not washing is advantageous unless other factors are involved, e.g. a large quantity of particulate material is present on the macroalgae. In contrast, washed samples used in an anaerobic digestion study gave higher methane yields in two thirds of the drying treatments than the unwashed, possibly due to lower salt-tolerance in the anaerobic microbial consortia, so a pre-washing step could be considered more suitable for this conversion route.