Microalgae cultivation for carbon dioxide sequestration and protein production using a high-efficiency photobioreactor system (original) (raw)

Production of Microalgal Biomass in Photobioreactors as Feedstock for Bioenergy and Other Uses: A Techno-Economic Study of Harvesting Stage

Applied Sciences, 2021

The cultivation of microalgae has become a viable option to mitigate increase in CO2 in the atmosphere generated by industrial activities since they can capture CO2 as a carbon source for growth. Besides, they produce significant amounts of oils, carbohydrates, proteins, and other compounds of economic interest. There are several investigations related to the process, however, there is still no optimal scenario, since may depend on the final use of the biomass. The objective of this work was to develop a techno-economic evaluation of various technologies in harvesting and drying stages. The techno-economic estimation of these technologies provides a variety of production scenarios. Photobioreactors were used considering 1 ha as a cultivation area and a biomass production of 22.66 g/m2/day and a CO2 capture of 148.4 tons/ha/year was estimated. The production scenarios considered in this study have high energy demand and high operating costs (12.09–12.51 kWh/kg and US $210.05–214.59/k...

Dataset on economic analysis of mass production of algae in LED-based photobioreactors

Data in Brief, 2019

The data presented in this article are related to the research article entitled "Sugar-stimulated CO 2 sequestration by the green microalga Chlorella vulgaris" (Fu et al., 2019) [1]. The data describe a rational design and scale-up of LED-based photobioreactors for producing value-added algal biomass while removing waste CO 2 from flu gases from power plants. The dataset were created from growth rate experiments for biomass production including direct biomass productivity data, PBR size and setup parameters, medium composition as well as indirect energy cost and overhead in Iceland. A complete economic analysis is formed through a cost breakdown as well as PBR scalability predictions.

Techno-economic analysis of microalgal biomass production in a 1-ha Green Wall Panel (GWP®) plant

Algal Research, 2016

The objective of this techno-economic analysis (TEA) was to define the production cost of the microalga Tetraselmis suecica in a 1-ha plant made of "Green Wall Panel-II" (GWP®-II) photobioreactors. The study was based on an energy analysis carried out for a similar plant located in Tuscany (Italy) and considers the steps from inoculum preparation to the wet algal paste. Costs of equipment and materials were obtained from manufacturers and suppliers, while operating costs and output data (e.g. biomass composition and productivity) were collected during several years of trials at the Fotosintetica & Microbiologica S.r.l. facilities (Florence, Italy). Other data were obtained from Microalghe Camporosso S.r.l. (Imperia, Italy), where a commercial 1500-m 2 GWP®-I plant is in operation and two 250-m 2 GWP®-II modules were built and used in the framework of the EU project BIOFAT. This TEA shows that, given a productivity of 36 tonnes per hectare per year, T. suecica biomass can be produced at a cost of €12.4 kg −1 (dry weight). Using conservative assumptions it was estimated that at the 100-ha scale the cost will be €5.1 kg −1. Locating the plant in more favorable climatic conditions (e.g. in Tunisia) will allow reaching 54 tonnes per hectare annually and reducing cost to €6.2 kg −1 at the 1-ha scale and to €3.2 kg −1 at the 100-ha scale. The major cost factors are labor at 1-ha scale in Tuscany and capital expenses in all the other cases. This TEA confirms that microalgal technologies have high potential not only for high-value, but also for medium-and low-value products, while the production of biofuels, protein, food and feed seems currently out of reach. However, the global scenario of agriculture commodities is rapidly changing and other factors (e.g. sustainability), besides a pure economic evaluation, will assume greater importance in the future.

Energy and economic analysis of microalgae cultivation in a photovoltaic-assisted greenhouse: Scenedesmus obliquus as a case study

Energy, 2017

Microalgal industrial production requires high surface area, resulting in production costs currently unacceptable. A possible optimization of land use for the cultivation of Scenedesmus obliquus is proposed, by conjoint production of biomass and electricity using photovoltaic cells (PV). For this purpose, biomass cultivation in a continuously operated 1 hectare open pond placed inside a greenhouse was considered, at two different Italian latitudes, as case studies. The greenhouse roof surface was partially covered with commercial PV modules, resulting in a reduced average irradiation. The light profiles and the average temperatures inside the greenhouse were simulated for different seasons, and the corresponding microalgal productivities were calculated based on a validated growth model. The partial pond shading limited photoinhibition in summer at Southern location, resulting in higher productivities. On the other hand, the loss of sunlight, due to the partial roof covering, resulted in a lower productivity in the other cases and for the Northern location. The presence of PV, however, allowed a better exploitation of light to produce electricity, which supports the energy duties of the process, with an additional net electricity production. Finally, an economic analysis was carried out showing a reduction of biomass production costs when PV is present.

Comparative life cycle assessment of real pilot reactors for microalgae cultivation in different seasons

2017

Microalgae are promising natural resources for biofuels, chemical, food and feed products. Besides their economic potential, the environmental sustainability must be examined. Cultivation has a significant environmental impact that depends on reactor selection and operating conditions. To identify the main environmental bottlenecks for scale-up to industrial facilities this study provides a comparative life cycle assessment (LCA) of open raceway ponds and tubular photobioreactors at pilot scale. The results are based on experimental data from real pilot plants operated in summer, fall and winter at AlgaePARC (Wageningen, The Netherlands). The energy consumption for temperature regulation presented the highest environmental burden. The production of nutrients affected some categories. Despite limited differences compared to the vertical system, the horizontal PBR was found the most efficient in terms of productivity and environmental impact. The ORP was, given the Dutch climatic cond...

Optimal integration of microalgae production with photovoltaic panels: environmental impacts and energy balance

Biotechnology for Biofuels

Background Microalgae are 10 to 20 times more productive than the current agricultural biodiesel producing oleaginous crops. However, they require larger energy supplies, so that their environmental impacts remain uncertain, as illustrated by the contradictory results in the literature. Besides, solar radiation is often too high relative to the photosynthetic capacity of microalgae. This leads to photosaturation, photoinhibition, overheating and eventually induces mortality. Shadowing microalgae with solar panels would, therefore, be a promising solution for both increasing productivity during hotter periods and producing local electricity for the process. The main objective of this study is to measure, via LCA framework, the energy performance and environmental impact of microalgae biodiesel produced in a solar greenhouse, alternating optimal microalgae species and photovoltaic panel (PV) coverage. A mathematical model is simulated to investigate the microalgae productivity in race...

Techno-economic and Fluid Dynamics Analysis for Growing Microalgae with the Intent of Producing Biofuel Using a System Model

2013

Techno-economic and systems studies on microalgal growth scenarios to date are abbreviated and missing a number of important variables. By including these variables in a detailed model integrating biology, chemistry, engineering, and financial aspects, a more defined systems analysis is possible. Through optimizing the model productivity based on the resulting net profit, the system analysis results in a more accurate assessment of environmental and economic sustainability of specific algal growth scenarios. Photobioreactor algal growth scenario optimization in the system model has resulted in realistic engineering design requirements based on algal growth requirements and fluid dynamics analysis. Results show feasibility for photobioreactor growth scenarios to be economically sustainable when co-products are included, but definite technological advancements and productivity improvements must be made. The main factors inhibiting a cost effective photobioreactor growth scenario are culture density, temperature, and lighting distribution for solar illuminated photobioreactors, and lighting cost for artificially illuminated photobioreactors. Open pond algal growth scenarios do not show any prospect of economic or environmental sustainability with current technology due to the large amount of surface area required, inefficient water use, and iii low culture density. All algal growth scenarios are inferior to petro-diesel regarding energy inputs, carbon emissions, and environmental sustainability. No algal growth scenarios analyzed in this study meet the U.S. requirement of biofuel emitting at least 20% less carbon emissions than diesel from crude oil. Dr. Robert M. Dores from the University of Denver, and Larry Clark from Lockheed Martin. Also, my deep appreciation for the assistance of Chad Van Fleet at Mathworks,

Dynamic Modeling of the Microalgae Cultivation Phase for Energy Production in Open Raceway Ponds and Flat Panel Photobioreactors

Frontiers in Energy Research, 2015

A dynamic model of microalgae cultivation phase is presented in this work. Two cultivation technologies are taken into account: the open raceway pond and the flat panel photobioreactor. For each technology, the model is able to evaluate the microalgae areal and volumetric productivity and the energy production and consumption. Differently from the most common existing models in literature, which deal with a specific part of the overall cultivation process, the model presented here includes all physical and chemical quantities that mostly affect microalgae growth: the equation of the specific growth rate for the microalgae is influenced by CO2 and nutrients concentration in the water, light intensity, temperature of the water in the reactor, and by the microalgae species being considered. All these input parameters can be tuned to obtain reliable predictions. A comparison with experimental data taken from the literature shows that the predictions are consistent and slightly overestimating the productivity in the case of closed photobioreactor. The results obtained by the simulation runs are consistent with those found in literature, being the areal productivity for the open raceway pond between 50 and 70 t/ (ha × year) in Southern Spain (Sevilla) and Brazil (Petrolina) and between 250 and 350 t/ (ha × year) for the flat panel photobioreactor in the same locations.