|CHAGAS, BRUNA - Universidade Federal Do Rio Grande Do Norte (UFRN)|
|MELO, MARCUS - Universidade Federal Do Rio Grande Do Norte (UFRN)|
|ATAIDE, CARLOS - Universidade Federal De Uberlândia|
Submitted to: Industrial and Engineering Chemistry Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/17/2016
Publication Date: 5/17/2016
Publication URL: http://handle.nal.usda.gov/10113/62689
Citation: Chagas, B.M., Mullen, C.A., Dorado, C., Elkasabi, Y.M., Boateng, A.A., Melo, M.A., Ataide, C.H. 2016. Stable bio-oil production from proteinaceous cyanobacteria: tail gas reactive pyrolysis of spirulina. Industrial and Engineering Chemistry Research. 55:6734-6741.
Interpretive Summary: Pyrolysis, the heating of organic material in the absence of oxygen, has the potential to convert biomass, the largest source of carbon available, to liquids that can be refined to renewable fuels and chemicals. However, because the liquid isolated from the pyrolysis of most biomass contains high levels of water, acids, and oxygen, it is problematic with regards to direct fuel applications. Therefore, scientists have sought new types of biomass with favorable composition for the pyrolysis process. Following on previous studies, where pyrolysis of proteinaceous feedstocks produced oils with greater stability, pyrolysis of spirulina, a variety of cyanobacteria made up of mostly protein, using the USDA-ARS tail gas reactive pyrolysis (TGRP) process was carried out. We found that when compared to conventional pyrolysis of spirulina, the TGRP process allowed for improved operational performance yielding mainly aromatic hydrocarbons with reduced viscosity and leading to increased energy content of the produced liquids. The increased stability made distillation of the liquid product possible allowing for valuable fuels and commodity chemicals to be successfully isolated. The information is beneficial to potential growers of aquatic energy crops and to those in the petrochemical industry looking to replace fossil fuel fuels with renewable alternatives.
Technical Abstract: Pyrolysis of Spirulina, a cyanobacteria with high levels of protein (74 wt %) and low levels of lipid (0.8 wt %) content, has the potential to produce fuels and platform chemicals that differ from those produced from lignocellulosic materials. The yields and product distribution from fluidized-bed pyrolysis of Spirulina using the USDA-ARS’s tail gas reactive pyrolysis (TGRP) process were evaluated and compared with those produced under an inert atmosphere. Important differences include improved performance of the system when using TGRP along with lower viscosity (77.6 – 148.5 cP at 27 degree C) and higher energy content (32.5– 33.5 MJ/Kg) of the bio-oil compared to conventionally produced liquids. Chemically, the TGRP bio-oils were comprised largely of aromatic hydrocarbons, phenols and nitrogenated compounds. This more stable mixture allowed for distillation of the bio-oil into fractions with higher concentrations of certain platform chemicals including phenolics and nitrogenated compounds such as pyrrole. In addition to the liquid, the bio-char and non-condensable gases had improved properties.