CHEMICAL ENGINEERING TRANSACTIONS
VOL. 49, 2016
A publication of
The Italian Association
of Chemical Engineering
Online at www.aidic.it/cet
Guest Editors: Enrico Bardone, Marco Bravi, Taj alli Keshavarz
Copyright © 2016, AIDIC Servizi S.r.l.,
I SBN 978-88-95608-40-2; I SSN 2283-9216
Conceptual Framework for the Production of Bioethanol and
Byproducts from Microalgae Biomass
Viviana Quintero*, Claudia Valderrama, Daniel Ortiz, Viatcheslav Kafarov
Universidad Industrial de Santander, Centro de Investigación en Desarrollo Sostenible en Industria y Energía. Carrera 9 #
27, Bucaramanga, 68002, Colombia.
vivana0520@gmail.com
Biofuel production from biomass is a promising alternative to fossil fuels. Biodiesel and bioethanol can be
produced from lipids and carbohydrates of microalgae biomass, respectively. In this paper, a processing
pathway from conceptual design process is proposed for liquid biofuels, to extract value-added products such
as pigments and proteins from microalgae (Chlorella vulgaris). The process diagram consists of six main
stages: vinasse anaerobic digestion, algae culture, biomass recovery, both bioethanol and biodiesel
production. Simulations in ASPEN PLUS® software were performed in order to evaluate the mass and energy
balances; heat integration using the Pinch Method was applied in order to minimize utilities consumption. 30
Ton/ h of vinasse were considered for treatment. Acid hydrolysis of cellulose to glucose was considered with a
96% performance and bioethanol production was carried out through a simultaneous saccharification and
fermentation process, with a yield of 92.3% on the stage, 112 kg/h of ethanol, 28.5 kg/h of biodiesel, 126.5
kg/h of protein and 3 kg/h of glycerol were obtained by the process simulation.
1. Introduction
Several products in commercial scale such as nutritional supplements for humans and animals, and feedstock
for pharmaceutical and cosmetic products are produced from microalgae. This source of biomass constitutes
a market of 5kt/year (Acién et al 2014). Recently the microalgae biomass has been considered as a third
generation feedstock for bioethanol production, because some microalgae species accumulate a large amount
of carbohydrates (40% w/w of the dry weight) in terms of starch and cellulose. These microalgae have
advantages over traditional feedstock as follows: high growth rate and productivity; short harvesting cycle (10
days), absence of lignin, requiring less pretreatment, and easy saccharification. Recent studies indicated that
the production of only one product from microalgae biomass is not economically feasible due to the current
market condition and production technology; for this reason the biorefinery concept has been identified as the
most promising way for the creation of an industry based on biomass (Ribiero, 2015). The concept of
biorefinery can be applied to microalgae biomass for the production of biofuels and high added value products
based on the composition of promising microalgae species. A microalgae based biorefinery must take into
account several issues for its sustainability such as water requirements, production costs, environmental
impacts and process efficiency.
2. Economic gross potential (EGP)
Economic gross potential (EGP) was used to determine the potential economic viability as shown in Ec (1), it
expresses mathematically the difference between the annual production flow by selling price and the annual
flow of raw material per unit cost. Table 1 shows the unit cost for the raw material used and the selling price
for the selected products presented. A result greater than zero indicates the process might be considered for a
more detailed analysis (El-Halwagi, 2012).
ࡱࡳࡼ =
∑ ܣݑ ݎݑݐ ݎݐ ݎݑ ݐ ∗ ݎ ݎݑ ݐ−
ேௗ௨௧
ୀଵ
∑ ܣݑ ݎݐ ݎݐ ∗ݎݐݎݑℎݏ ݎ ݎݐ ݎݐ
ே ௧௧௦
ୀଵ
(1)
DOI: 10.3303/CET1649066
Please cite this article as: Quintero V., Valderrama C., Ortiz D., Kafarov V., 2016, Conceptual framework for the production of bioethanol and
byproducts from microalgae biomass, Chemical Engineering Transactions, 49, 391-396 DOI: 10.3303/CET1649066
391