Energy use and greenhouse gas emissions from an algae fractionation process for producing renewable diesel

Abstract

In one approach to algal biofuel production, lipids are extracted and converted to renewable diesel and non-lipid remnants are converted to biogas, which is used for renewable heat and power to support the process. Since biofuel economics benefit from increased fuel yield, the National Renewable Energy Laboratory analyzed an alternative pathway that extracts lipids and also makes ethanol from carbohydrates in the biomass. In this paper, we examine the environmental sustainability of this "fractionation pathway" through life-cycle analysis (LCA) of greenhouse gas emissions and energy use. When the feedstock productivity was 30 (18) g/m 2 /d, this pathway emitted 31 (36) gCO 2 e/MJ of total fuel, which is less than the emissions associated with conventional low sulfur petroleum diesel (96 gCO 2 e/MJ). The fractionation pathway performed well in this model despite the diversion of carbon to the ethanol fuel.

Life-cycle analysis of energy use, greenhouse gas emissions, and water consumption in the 2016 MYPP algal biofuel scenarios

“…See the MYPP (2016) report for details of the cultivation assumptions that were selected from the Farm Report. An LCA of energy use and GHG emissions in the CAP pathway for the Original 2022 Target is in the literature (Pegallapati and Frank, 2016). and Davis et al (2014a) provided energy and material inventories for the CAP process while Jones and Zhu (2016) and Jones et al (2014) provided energy and material balances for the HTL pathway (private communications).…”

An experimental study verification of production raw algae oil to biodiesel by industry 4.0

“…In another study, Keris-Sen et al [2] developed ultrasonic assisted solvent extraction method to increase oil extraction efficiency 1.5-2 times. Oil extraction efficiency may vary according to the method used in the oil extraction process [1][2][3][4][5][6]. In Table 1, advantages and disadvantages of different harvesting methods are shown.…”

An Assessment Of Microalgal Biodiesel With Acetone, Butanol and Ethanol Using LIfe Cycle Assessment (LCA) Methodology

“…Centrifuges are usually decanters or disk stack. Decanter centrifuges require high inlet cell concentrations (>10%), yield algal pastes of up to 40% or more in dry weight and require approximately 8 kWh/m 3 culture volume (Shelef et al, 1984;Wiley et al, 2011 Figure 2.10: Pre-treatment process schematic for microalgal biomassadapted from (Bradley et al 2015;Dong et al 2016;Gnansounou & Raman, 2016;Pegallapati & Frank 2016;Yuan et al, 2015) Drying and crushing…”