Investigating the influence of acid washing pretreatment and Zn/activated biochar catalyst on thermal conversion of Cladophora glomerata to value-added bio-products

The production of sustainable energy resources are of great importance in the energy industry. As a result, studies have been extremely concerned with the conversion of coastal macroalgae into bio-products mostly through thermochemical processes such as pyrolysis. This study aimed to produce high efficiency value-added bioproducts through the pyrolysis of the acid-washed Cladophora glomerata (ACG). It also attempted to upgrade the bio-products through the catalytic pyrolysis with the use of Zn/Activated biochar (Zn/C) catalyst. The catalyst was prepared via the carbonization of the ZnCl2 impregnated ACG under the optimal reaction conditions and was characterized by BET, XRD, FT-IR, FESEM-EDS and ICP analyzes. The experimental results indicated that the acid washing pretreatment led to the removal of inorganic contents of the biomass, and consequently to the significant increase in the bio-oil yield. In addition to this remarkable change in the product distributions and according to the results of the catalytic experiment, the Zn/C catalyst decreased the acid and oxygen contents of the bio-oil. It also increased the aromatic contents of the bio-oil and promoted H-2 production. Accordingly, it favorably upgraded the quality of the bio-oil and pyro-gas. The study concludes that Cladophora macroalgae can be widely used as both feedstock and catalyst in order to produce value-added bio-products in the energy industry.