A Dynamic Optimization Model for Designing Open-Channel Raceway Ponds for Batch Production of Algal Biomass

Abstract

This work focuses on designing the optimum raceway pond by considering the effects of sunlight availability, temperature fluctuations, and harvest time on algae growth, and introduces a dynamic programing model to do so. Culture properties such as biomass productivity, growth rate, and concentration, and physical properties, such as average velocity, pond temperature, and rate of evaporation, were estimated daily depending on the dynamic behavior of solar zenith angle, diurnal pattern of solar irradiance, and temperature fluctuations at the location. Case studies consider two algae species (Phaeodactylum. tricornutum and Isochrysis. galbana) and four locations (Tulsa, USA; Hyderabad, India; Cape Town, South Africa; and Rio de Janeiro, Brazil). They investigate the influences of the type of algae strain and geographical location on algae biomass production costs. From our case studies, the combination of I. galbana species grown in Hyderabad, India, with a raceway pond geometry of 30 cm channel depth, about a meter channel width, and 300 m in length, and a harvest interval of every six days yielded the minimum algal biomass production costs. The results of the sensitivity analysis reveal that smaller channel depths and longer ponds (within the ranges considered) are recommended to minimize the net present cost of algae biomass production.

Novel Stacked Modular Open Raceway Ponds for Microalgae Biomass Cultivation in Biogas Plants: Preliminary Design and Modelling

“…The design, the operation and monitoring of the pilot SMORP module was supported by the latest best practices for microalgae cultivation as explained within the project EnAlgae [45] and from the technological solutions according to Chisti [46] and Yadala [57] widely used in commercial production of algal biomass.…”

“…2). Some studies have shown that a higher L/W ratio (L/W ≤ 11) is better in terms of flow dynamics of the system [46], [57]. However, one of the prime objectives of the proposed pilot concept is to evaluate the overall effectiveness of a "stacked modularity" of the open pond system consisting of a number of ponds with a comparatively low L/W ratio for a better mechanical resistance of the structure.…”

Improved Production of Astaxanthin from Haematococcus pluvialis Using a Hybrid Open–Closed Cultivation System

“…These agents are important bioactive components in antiaging serums, sunblock creams, and beauty products, and are also provided as oral dietary supplements at a recommended dose of 4 mg per day. They also have anti-gastric, anti-cancer, anti-inflammatory, antidiabetic, anti-obesity, ocular-protective, and immune response-boosting properties, and many studies are currently underway to explore their immense potential for biological applications [17,18,[21][22][23].…”

Utilizing a CHP Power Plant’s Energy and CO2 Emissions for the Manufacture of Affordable and Carbon Neutral Algae Bioplastic for Re-Useable Packaging

“…OPRs are constructed to have high average depths of 0.25–0.30 m which equates to a low surface-to-volume ( S / V ) ratio of about 5.0–10.0 m –1 . This greatly reduces sunlight exposure and the photosynthetic growth of the algae culture to a maximum capacity of 0.5–1.0 kg biomass /m 3 of cultivation after 4–6 weeks. , Naturally, poor algae biomass concentrations result in poor economic profitability due to the energy necessary for drying the wet biomass. ,, While closed reactors, such as tubular or flat panel/plate photobioreactors (PBR) have higher S / V ratios (∼50–150) and better biomass productivities (e.g., 6–12 g/L), , their capital costs are 100 times greater than ORPs . As well, the scale of these PBRs are usually limited to 100 m 2 , or 0.1–10 m 3 , due to their low light distribution efficiencies of 10–20% and their large gas exchange requirements. , Naturally, this incurs large utility costs due to high energy consumptions of 76–3400 W/m 3 for tubular PBRs to 50–334 W/m 3 for flat panels and plates. ,− To transcend the limitations affecting the development of large-scale algae-based bioplastic manufacture, implementation of improved PBRs such as the thin layer cascade (TLC), and the sourcing of materials (e.g., wastewater to CO 2 ) to electricity and heating from bioenergy plants, are 2 solutions being pursued.…”

“…52,53 Naturally, poor algae biomass concentrations result in poor economic profitability due to the energy necessary for drying the wet biomass. 50,54,55 While closed reactors, such as tubular or flat panel/plate photobioreactors (PBR) have higher S/V ratios (∼50−150) and better biomass productivities (e.g., 6−12 g/L), 56,57 their capital costs are 100 times greater than ORPs. 54 As well, the scale of these PBRs are usually limited to 100 m 2 , or 0.1−10 m 3 , due to their low light distribution efficiencies of 10−20% 58 and their large gas exchange requirements.…”