Open aquatic algae cultivation system with semipermeable liner sections for improved environmental uptake of carbon dioxide
View Patent ↗An open aquatic algae cultivation system (OAACS) with an algae impermeable liner that includes semipermeable liner sections for improved environmental uptake of carbon dioxide is disclosed. OAACS comprises a buoyant framework, an algae impermeable liner with a structure largely impermeable to the cultivated algae culture but with semipermeable liner sections permeable to dissolved inorganic carbon, a culture, and a mooring system. Practical semipermeable liner sections are also disclosed.
1 . A floating generally rectangular algae cultivation system with a length, a width, and ends designed for flotation and positioning on the surface of a body of water and wherein the positioning is for creation of a unidirectional longitudinal wind driven surface current of an algae culture within the system comprising:
a) a buoyant framework arranged into longitudinal members along the entire length and transverse members along the entire width with a set of two longitudinal and two transverse members forming all four of the ends and at least one interior transverse member, wherein the longitudinal and transverse members comprise pipes that are conduits for a plurality of process fluids selected from the group comprising nutrient feeds, culture, and surrounding water;
b) an algae impermeable liner comprising at least three sections, wherein each section is attached to the longitudinal members and adjacent sections are attached either to each other or to an interior transverse member, wherein the buoyant framework and the algae impermeable liner create a containment structure and the at least three sections comprise;
i. at least two semipermeable liner sections having two planar surfaces, an interior, and pores through the interior, wherein the semipermeable liner sections are permeable to dissolved inorganic carbon; and
ii. at least one nutrient impermeable liner section that is impermeable to nutrients added to the system;
wherein the at least three sections are arranged consecutively from upstream to downstream such that one semipermeable liner section starts upstream of the at least one interior transverse member and continues downstream to it; one nutrient impermeable liner section starts at the at least one interior member and continues downstream from it, and one semipermeable liner section starts at the downstream end of the one nutrient impermeable liner section and continues downstream from it;
c) a mooring system; and
d) at least one of culture harvesting and nutrient replenishment systems positioned at each of the two transverse members forming two of the ends and the at least one interior transverse member.
2 . The algae cultivation system according to claim 1 wherein the mooring system comprises a mooring line.
3 . The algae cultivation system according to claim 1 wherein the mooring system comprises a buoy system.
4 . The algae cultivation system according to claim 1 wherein the buoyant framework comprises at least one bundle of at least two tubes.
5 . The algae cultivation system according to claim 1 wherein at least one of the longitudinal members connects to at least one of a ship, platform, buoy, tank, or a piping network.
6 . The algae cultivation system according to claim 1 wherein the nutrient feeds include at least one selected from the group consisting of nitrogen, iron, and phosphorous.
7 . The algae cultivation system according to claim 1 wherein the interior transverse member further comprises at least one platform.
8 . The algae cultivation system according to claim 7 wherein the at least one platform comprises at least one platform support that floats in the culture and is arranged to form lengthwise channels together with the algae impermeable liner.
9 . The algae cultivation system according to claim 1 wherein the system is more than 1 kilometer long and more than 100 meters wide.
10 . The algae cultivation system according to claim 1 which further comprises a submersion system for lowering the cultivation system below the surface of the body of water.
11 . The algae cultivation system according to claim 10 wherein the longitudinal members comprise at least one bundle of at least two pipes and at least one of the pipes is a ballast tube.
12 . The algae cultivation system according to claim 11 wherein the submersion system comprises systems to change the buoyancy of the ballast tube.
13 . The algae cultivation system according to claim 10 which further comprises a depth pressure sensor for controlling the depth of submersion of the algae cultivation system.
14 . The algae cultivation system according to claim 10 wherein the submersion system comprises a winch system.
15 . The algae cultivation system according to claim 14 wherein the winch system comprises a free hanging submerging line that extends to a subsurface.
16 . The algae cultivation system according to claim 1 wherein there are at least two algae cultivation systems.
17 . The algae cultivation system according to claim 1 wherein the cultivation system further comprises the process fluids.
18 . The algae cultivation system according to claim 17 wherein the process fluids comprise a culture in the containment structure.
19 . The algae cultivation system according to claim 1 wherein the semipermeable liner section comprises fibers.
20 . The algae cultivation system according to claim 19 wherein the fibers comprise at least one hydrophobic polymer.
21 . The algae cultivation system according to claim 20 wherein the fibers further comprise an amphiphilic molecule.
22 . The algae cultivation system according to claim 21 wherein the amphiphilic molecule is glycerol monostearate.
23 . The algae cultivation system according to claim 21 wherein the amphiphilic molecule has an average of n hydrophobic groups, wherein n is large.
24 . The algae cultivation system according to claim 23 wherein the amphiphilic molecule is poly[(vinyl alcohol)-(stearic acid)].
25 . The algae cultivation system according to claim 1 wherein the semipermeable liner section comprises a gradient of pore sizes with the largest pores on the surfaces of the liner and the smallest pores in the interior of the liner.