A Framework to Report the Production of Renewable Diesel from Algae

Abstract

Recently, algae have received significant interest as a potential feedstock for renewable diesel (such as biodiesel), and many researchers have attempted to quantify this potential. Some of these attempts are less useful because they have not incorporated specific values of algal lipid content, have not included processing inefficiencies, or omitted processing steps required for renewable diesel production. Furthermore, the associated energy, materials, and costs requirements are sometimes omitted. The accuracy and applicability of these estimates can be improved by using data that are more specific, including all relevant information for renewable diesel production, and by presenting information with more relevant metrics. To determine whether algae are a viable source for renewable diesel, three questions that must be answered are (1) how much renewable diesel can be produced from algae, (2) what is the financial cost of production, and (3) what is the energy ratio of production? To help accurately answer these questions, we propose an analytical framework and associated nomenclature system for characterizing renewable diesel production from algae. The three production pathways discussed in this study are the transesterification of extracted algal lipids, thermochemical conversion of algal biomass, and conversion of secreted algal oils. The nomenclature system is initially presented from a top-level perspective that is applicable to all production pathways for renewable diesel from algae. Then, the nomenclature is expanded to characterize the production of renewable diesel (specifically, biodiesel) from extracted algal lipids in detail (cf. Appendix 2). The analytical framework uses the presented nomenclature system and includes three main principles: using appropriate reporting metrics, using symbolic notation to represent unknown values, and presenting results that are specific to algal species, growth conditions, and product composition.

Comprehensive Evaluation of Algal Biofuel Production: Experimental and Target Results

“…The production pathway and experimental methods used in this analysis has been described in detail in previous publications [6,14,19,20]. Furthermore, the materials and energy consumption data used in the Experimental Case and the Highly Productive Case are taken from Beal et al that calculated the second-order energy return on (energy) investment (2 nd O EROI) [14].…”

“…Figure 1. The production pathway is represented as three phases: growth, processing, and refining [6]. The data used for each input and output are shown for the Experimental Case (top) and Highly Productive Case (bottom).…”

“…Each efficiency is defined as the mass of the output divided by the mass of the input for that step (cf. [6]). For example, the biocrude separations efficiency, , is defined as the mass of biocrude recovered divided by the lysed algal biomass, and the neutral lipid fraction is embedded in this efficiency [6].…”

“…This study examines these criteria for two cases using second-order analysis methods described by Mulder and Hagens [5], which include direct and indirect operating expenses, but neglect all capital expense. Process-specific terminology is based on the reporting framework established by Beal et al [6].…”

Phytoremediation for Green Energy

“…The organic waste water has a really high amount of biomass for hydrogen production using microbial organisms (Beal et al 2011). The organic waste water has a really high amount of biomass for hydrogen production using microbial organisms (Beal et al 2011).…”