title: Hydrothermal pretreatment of microalgae for production of pyrolytic bio-oil with a low nitrogen content.
abstract: Microalgae can be converted to an energy-dense bio-oil via pyrolysis; however, the relatively high nitrogen content of this bio-oil presents a challenge for its direct use as fuels. Therefore, hydrothermal pretreatment was employed to reduce the N content in Nannochloropsis oculata feedstock by removing proteins without requiring significant energy inputs. The effects of reaction conditions on the yield and composition of pretreated algae were investigated by varying the temperature (150-225°C) and reaction time (10-60 min). Compared with untreated algae, pretreated samples had higher carbon contents and enhanced heating values under all reaction conditions and 6-42% lower N contents at 200-225°C for 30-60 min. The pyrolytic bio-oil from pretreated algae contained less N-containing compounds than that from untreated samples and the bio-oil contained mainly (44.9% GC-MS peak area) long-chain fatty acids (C14-C18) which can be more readily converted into hydrocarbon fuels in the presence of simple catalysts.
authors: Center for Biorefining and Department of Bioproducts and Biosystems Engineering, University of Minnesota, 1390 Eckles Ave., St. Paul, MN 55108, USA.
authors: Zhenyi
authors: Z
authors: Du
authors: Michael
authors: M
authors: Mohr
authors: Xiaochen
authors: X
authors: Ma
authors: Yanling
authors: Y
authors: Cheng
authors: Xiangyang
authors: X
authors: Lin
authors: Yuhuan
authors: Y
authors: Liu
authors: Wenguang
authors: W
authors: Zhou
authors: Paul
authors: P
authors: Chen
authors: Roger
authors: R
authors: Ruan
mesh_terms: D056804:Biofuels / Q000382:microbiology*; D018533:Biomass; D001709:Biotechnology / Q000379:methods*; D002244:Carbon / Q000378:metabolism; D005227:Fatty Acids / Q000378:metabolism; D008401:Gas Chromatography-Mass Spectrometry; D006813:Humidity; D058086:Microalgae / Q000166:cytology / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism*; D013696:Temperature; D013997:Time Factors; D014867:Water / Q000737:chemistry*
chemical_list: D056804:Biofuels; D005227:Fatty Acids; D014867:Water; D002244:Carbon; D009584:Nitrogen