Grantee Research Project Results
Final Report: An integrated platform for producing biofuels from sweet sorghum bagasse
EPA Grant Number: SU836118Title: An integrated platform for producing biofuels from sweet sorghum bagasse
Investigators: Liang, Yanna , Wiltowski, Tomasz
Institution: Southern Illinois University - Carbondale
EPA Project Officer: Page, Angela
Phase: I
Project Period: September 1, 2015 through August 31, 2016
Project Amount: $15,000
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet (2015) RFA Text | Recipients Lists
Research Category: P3 Awards , Pollution Prevention/Sustainable Development , Sustainable and Healthy Communities , P3 Challenge Area - Air Quality
Objective:
It is commonly recognized that continued use of fossil fuels is not sustainable. To maintain sustainable development of our society, we must replace fossil fuels with those that are renewable, environmentally friendly, and domestic. Biofuels produced from lignocellulosic biomass meet these criteria perfectly. In our lab, we have developed a simple but effective pathway to produce biodiesel from sweet sorghum bagasse through a combination of pretreatment, fermentation, and in situ transesterification. However, two materials, YCR and PWS are left unused. Thus, the goal of this project is to convert these two wet materials separately to bio-oil through HTL. The specific objectives are:
- Testing the yield of bio-oil from YCR and PWS under different reaction conditions.
- Characterizing the top-three bio-oil samples (yield based) and the corresponding aqueous phases for each of the two target materials.
Summary/Accomplishments (Outputs/Outcomes):
As of now, we have accomplished Objective #1 and half of Objective #2. Under Objective #1, for PWS, homogenous catalysts (formic acid; potassium carbonate (K2CO3); potassium hydroxide (KOH), each at 1 mol/L (M)) at 300 and 350 degrees C all led to higher bio-oil yields compared with controls without addition of a catalyst. Heterogeneous catalysts (Nickel phosphide (Ni2P); Nickle on silica alumina (Ni/Si-Al) and zeolite, each at 2% dry wt%), however, resulted in less biocrude yields compared to the controls except those with Ni/Si-Al at 300 degrees C. In addition, bio-oil yields at 300 degrees C were all higher than the counterparts at 350 degrees C except those with formic acid or KOH as the catalyst. Regarding the ones with formic acid, the bio-oil yield was 38.0 + 10.6% and 44. 0 + 4.9% at 300 and 350 degrees C, respectively. For those with KOH, yield of bio-oil was 42.2 + 9.5% at 300 degrees C and 44.0 + 6.4% at 350 degrees C. Thus, the differences between the two temperatures were not statistically significant. Considering all results, the top three bio-oil samples were identified as those obtained with K2CO3, KOH, or Ni/Si-Al as the catalyst at 300 degrees C. The bio-oil yield was 61.8 + 1.1%, 42.2 + 9.5% or 45.5 + 3.5% in the same order.
Regarding YCR, at both temperatures, all the catalysts brought higher bio-oil yields compared to the controls. And bio-oil yields at 350 degrees C were all higher than those at 30 degrees C with the same catalyst. The conditions that led to the highest three bio-oil yields were: K2CO3 (68.9 + 2.3%) at 350 degrees C, KOH (67.0 + 2.8%) at 350 degrees C, and K2CO3 (63.9 + 3.0%) at 300 degrees C.
Under Objective #2, for each target material, the bio-oil samples derived from three top-performing conditions were proceeded to characterization. Based on results from elemental analysis, for PWS, the best bio-oil samples were those from using K2CO3 as the catalyst at 300 degrees C. These oil samples had a nitrogen (N), carbon (C), hydrogen (H), sulfur (S), oxygen (O) content of 0.470%, 73.240%, 7.666%, 0.249% and 14.988%, respectively. According to an equation of HHV (higher heating value) (MJ/kg) = 0.338 C + 1.428 (H - O/8) + 0.095 S, the HHV was 33.051 MJ/Kg. Compared to those from using KOH or Ni/Si-Al as the catalyst at the same temperature, the HHV values were much higher resulting from a much higher C content. In terms of YCR, the use of K2CO3 at 300 degrees C also led to the highest HHV of 40.419 MJ/Kg. Although this HHV was not significantly higher than 39.591 MJ/Kg from using KOH as the catalyst at 350 degrees C, content of O (9.886%) of the former was lower than that of the latter (11.379%).
In addition, the top three bio-oil samples from PWS were analyzed by a Gas Chromatography Mass Spectrometry (GC/MS). Through using anthracene as an internal standard, all the identified peaks (≥ 90% confidence) were quantified. Overall, 51.01% of all peak areas were identified, which corresponded to 30.30% of the total mass of the bio-oil sample. The majority of chemicals belonged to phenols, alcohols, and hydrocarbons. Furthermore, the aqueous phase samples corresponding to the top three oil samples were subjected to High Performance Liquid Chromatography (HPLC) analysis. Although different samples had different chemical compositions, lactic acid, formic acid and acetic acid appeared in all three.
Conclusions:
Overall, we have successfully: (1) screened six catalysts for HTL of the PWS and YCR that have never been investigated before; (2) selected K2CO3 as the best catalyst for the highest yield of biocrude for these two materials; and (3) characterized the top biocrude samples in terms of elemental and chemical compositions. All of these accomplishments proved that our Phase I proposed approaches are technically feasible.
Journal Articles on this Report : 1 Displayed | Download in RIS Format
Other project views: | All 1 publications | 1 publications in selected types | All 1 journal articles |
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Bi Z, Zhang J, Zhu Z, Liang Y, Wiltowski T. Generating biocrude from partially defatted Cryptococcus curvatus yeast residues through catalytic hydrothermal liquefaction. APPLIED ENERGY 2018;209:435-444. |
SU836118 (Final) |
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Supplemental Keywords:
waste to fuel, environmental education, sustainabilityThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.