Extracting phycocyanin from spirulina and hydrothermal liquefaction of its residues to produce bio-crude oil

Microalgae is a promising biofuel source with high photosynthetic efficiency, and it often contains high-value substances for nutritional, pharmaceutical and medical applications. In order to improve the economic viability of the spirulina utilization, this study investigated a cost competitive biotechnological process for C-phycocyanin (C-PC) extraction from spirulina platensis. The residual biomass after C-PC extraction was converted into bio-crude oil via hydrothermal liquefaction (HTL). The HTL bio-crude oil obtained from the original spirulina feedstock and the residual after the C-PC extraction were compared. A rapid and efficient process for extraction and purification of food-level C-PC from spirulina platensis was developed in this study. The process conditions include: 1) freeze the spirulina 3 hours to extract the crude protein; 2) add 80 g/L (w/v) activated carbon to the crude extract; 3) use a vacuum filter with a 0.22 μm pore size membrane to collect the extract; and 4) freeze dry the extract to get the C-PC powder. The yield of the C-PC production is 27% and the cost (exclude labor) for entire process is $26.1/kg. After C-PC extraction, there is still 63% dry biomass left which was used for conversion into bio-crude oil via HTL. The HTL bio-oil products distribution as well as their composition, reaction pathways and energy recovery via HTL were investigated. HTL was conducted at temperatures range from 260˚C to 300˚C at 0.7 MPa N2 initial pressures. The highest bio-crude oil yield of 38 % (based on dry volatile matter) was obtained at 300˚C. The highest higher heating value is 37.1 MJ/kg occurred at 300°C reaction temperature. Elemental analysis revealed that the decarboxylation and denitrification may be dominant from 260˚C to 300°C following repolymerization governing at higher temperature; TG analysis showed that approximately 75.4 % distilled bio-crude products were in the range of 200-550°C. These distillates can be further upgraded for transportation fuels.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Agricultural & Biological Engr

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2016

Author dc:creator

• Guan, Shaochen

Contributors dc:contributor

• Zhang, Yuanhui
• Schideman, Lance Charles
• Martins, Marcio Arêdes

• Extraction
• Purification
• Spirulina
• Phycocyanin
• Bio-crude oil
• Hydrothermal liquefaction

Statement dc:rights

• Copyright 2016 Shaochen Guan

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/92665

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/92665