Turning recovered algal biomass and oyster shells into resources
Bloom Biomass Utilization
From Byproduct to Value
The algal biomass recovered by Bloomo’s water treatment process, and the large volumes of oyster shell produced as a by-product of oyster farming, become high-value resources given the right equipment and assessment methods. Through multi-stage conversion into aquaculture feed, soil amendments, construction materials and fertilizer feedstock, and quantitative assessment of carbon fixation based on LCA/MRV, aquatic biomass becomes a core asset of the circular economy.
Why biomass utilisation matters now
The problem on the algal biomass side
- Profitability at industrial scale is governed by the cost of the harvesting and drying steps. Centrifugation recovers ≥90% but takes 0.8–1.2 kWh/m³, and spray drying requires ≥3 MJ/kg[1]
- Biomass production cost in commercial continuous cultivation is 53.32 €/kg DW, with harvesting and dewatering making up 20–30% of the total[2][3]
- For feed use, the acceptable inclusion rate differs greatly by species (carp 100%, shrimp 95%, salmonids 18.6% and so on), so species-specific design and processing determine performance[4]
The problem on the oyster shell side
- East and Southeast Asia generate 6–8 million tonnes of mariculture waste a year. Taiwan alone accounts for about 2.2 million tonnes[5]
- The shell makes up about 70% of live weight relative to the edible portion, and disposal cost grows as farming scales up[6]
- About 95% of an oyster shell is CaCO₃[6], and its potential use in construction materials, soil amendments, water treatment media and feed additives has been reported[7] — but quantitative LCA assessment by operators remains rare
A scientific caveat: oyster shells and carbon fixation
Because the calcification of an oyster shell is accompanied by a CO₂-releasing reaction, research has pointed out that the short-term contribution to reducing atmospheric CO₂ can be net zero or even negative[8][9]. Without long-term use (as a material lasting a century or more, for instance) and appropriate LCA boundaries, carbon fixation cannot simply be claimed. Novelgen develops on the principle of assessing carbon value only under LCA boundary conditions conforming to ISO 14040/14044.
Novelgen’s approach
Novelgen is developing equipment that handles algal biomass and oyster shell together, on site — at land-based farms, sewage treatment plants and coastal fishing ports. As the downstream stage connected to Bloomo, it makes solid–liquid separation → drying → grinding and particle sizing continuous, and is designed so that process conditions can be chosen per application.
For feed
Processing conditions premised on high purity and retained protein content
Biochar
Moisture management and drying designed for pyrolysis
Soil amendment
Particle size and pH adjusted for compounding with oyster shell
Beyond that, Bloomo Cloud Service continuously records throughput, energy input and CO₂ fixed, with the development goal of providing operators the MRV data needed for carbon credits, under LCA boundary conditions conforming to ISO 14040/14044.
Technical specifications and key figures
Every figure states its source. Research finding / Development target marks values from the academic literature and Novelgen development targets respectively.
Algal biomass processing
Algal biomass processing — detail
| Metric | Value | Category | Source |
|---|---|---|---|
| Biomass concentration at PBR outlet | 0.3–0.4% DW (closed system) | Research finding | [3] |
| Solids in slurry after dewatering | 15–25% | Research finding | [3] |
| Moisture after final drying | <5% (long-term storage and transport requirement) | Research finding | [3] |
| Centrifugation energy | 0.8–1.2 kWh/m³ | Research finding | [1] |
| Spray drying energy | About 0.8–1.0 kWh/kg | Research finding | [1] |
| Algal protein content | 40–70 wt% (Chlorella 51–58%, Spirulina 60–71%, Arthrospira 70%) | Research finding | [10] |
| CO₂ uptake ratio (photosynthesis) | About 1.83 t CO₂ per tonne of biomass | Research finding | [11] |
Oyster shell as a resource
Oyster shell as a resource — detail
| Metric | Value | Category | Source |
|---|---|---|---|
| Calcium carbonate content | About 95% | Research finding | [6] |
| Share of live weight made up by the shell | About 70% | Research finding | [6] |
| Soil amendment application rate (published) | 750–2,250 kg/ha (5-year trial on acidic red soil) | Research finding | [12] |
| LCA for the CaCO₃ route | About 729.9 kg CO₂-eq/t (electricity contributing 91.7%, China case) | Research finding | [13] |
| CaO route (calcination) | Assuming renewables, 84% lower environmental impact by 2050 | Research finding | [13] |
Value streams — three routes to a resource
Biomass Circulation Flow
Note: the biomass processing unit is in development. The flow diagram shows the design concept.
Aquaculture and livestock feed
Principal forms of use
- Fine-particle feed for larval fish and bivalve seedlings (Business model 1)
- B2B supply as a compound feed ingredient
- Feed production alongside RAS (Business model 2)
Equipment that pellets the high-protein algae from Bloomo cultivation (40–70 wt%[10]) on site brings the feed supply chain to where it is used (in development). Microalgae serve as a direct nutrient source at the early developmental stages of bivalves and crustaceans, and continuous supply gives an advantage in density and freshness management.
Protein, ω-3 PUFA and carotenoid composition can be selected by species — Chlorella, Spirulina, Nannochloropsis and others[4][10]. By treating aquaculture effluent with Bloomo inside the RAS and turning the resulting biomass into feed within the same facility, the design aims at full circulation with no logistics in between.
Note: this indicates potential as a feed ingredient. It is not a guarantee of specific nutritional value or disease-prevention effect. For inclusion rates by species, see the literature[4].
Biomaterials (compound use with oyster shell)
Principal product lines
- CaCO₃ for construction (substitute for fine concrete aggregate)
- Soil amendment (oyster shell powder + algal biochar)
- Feedstock for CO₂ mineralisation (CaO route)
Mechanical grinding makes it usable as a substitute for fine concrete aggregate[7][6], with pre-treatment securing the particle size and purity that do not impede cement hydration. A compound soil amendment combining the pH buffering of oyster shell with the water retention and carbon fixation of algal biochar improved every indicator — yield, soil acidity and Cd accumulation — at an application rate of 1,500 kg/ha in a five-year trial on acidic soil (peanuts and other crops)[12].
CO₂ mineralisation (the CaO route) calcines the shell into CaO and fixes flue-gas CO₂ as CaCO₃[5]; an LCA assuming renewables estimates an 84% reduction in environmental impact by 2050[13].
Nitrogen and phosphorus fertilizer
Principal forms of use
- Liquid and slurry fertilizer (using the partly dewatered slurry directly)
- Solid pelleted fertilizer (compression moulding)
- Resource recovery integrated with sewage treatment
Through the nitrogen assimilation of Algal Bloom Capture, the NH₄⁺ and PO₄³⁻ in the water being treated are held in the algal biomass as protein and polyphosphate. Unlike conventional nitrification–denitrification, this is a design that does not lose nitrogen to the atmosphere.
Note: this indicates potential as a fertilizer feedstock. It is not a guaranteed composition statement under fertilizer regulations.
Market opportunity and positioning
0.783 → 1.38
US$ bn (2024→2032)
Algal biomass market
CAGR about 7.3%
Three demands expanding in parallel: sustainability requirements in aquaculture feed (fishmeal substitution), animal-free demand for agricultural soil amendments, and low-carbon construction materials.
Fragmented → integrated
Regional GX projects expanding
Oyster shell resource market
Hiroshima, Miyagi, Okayama and others
Regional GX projects such as HIROSHIMA SANDBOX are under way, and the institutional framework for carbon credits is taking shape. The market is in transition from fragmented handling to integrated solutions.
GX / ESG
Decarbonisation and circularity requirements
Regulatory tailwind
EU WFD and other international standards
Japan’s GX Promotion Act, the EU Water Framework Directive and the J-Credit scheme, among other tightening regulations, push the need to turn waste into resource.
Positioning — competitive matrix
Higher value
Lower value
Integrated
Fragmented
Novelgen
Bloomo integration + LCA/MRV
All three streams at once
Existing waste handlers
Single use / cost-driven
Major chemical & feed manufacturers
High value but a single step
What sets us apart: seamless integration with Bloomo cultivation / carbon valuation through automatic recording of LCA and MRV data / all streams handled at once. TAM/SAM/SOM figures are kept indicative; see the pitch materials for detail.
Development and track record
Achievements so far (2023–2025)
Hiroshima Prefecture carbon recycling programme
Combined farming of Pacific oyster and microalgae
Selected for the SBIR Phase 3 fund
MAFF SME innovation promotion programme (oyster fattening system and aquatic distribution DX)
Selected for SBIR Phase 2
Recirculating aquaculture
Bloom Oyster test shipment
Start of the market supply phase
Selected for HIROSHIMA SANDBOX
Certified by the Hiroshima Industrial Promotion Organization
Currently in development
Prototype on-site dewatering and particle-sizing unit for algal biomass (downstream of Bloomo)
Oyster shell grinding × algal biochar blending unit
Bloomo Cloud Service extension linked to LCA and MRV
Milestones ahead
Standardising commercial-scale harvesting and drying equipment
Designing the connection to carbon and biodiversity credits
Establishing processes conforming to the EU WFD and other international standards
Note: the achievements listed are based on information already announced publicly. Equipment specifications and the development schedule may change as demonstration progresses.
References
- "Microalgal biorefineries: a systematic review of technological trade-offs and innovation pathways." PMC12357411. PMC →
- Pereira H. et al. "Techno-economic assessment of microalgae production, harvesting and drying for food, feed, cosmetics, and agriculture." Science of The Total Environment, 2022. PMID: 35526636. PubMed →
- Fasaei F. et al. "Techno-economic evaluation of microalgae harvesting and dewatering systems." Algal Research, 2018. ScienceDirect →
- Siddik M.A.B. et al. "Expanded utilisation of microalgae in global aquafeeds." Reviews in Aquaculture, 2024. DOI →
- "Sustainable conversion of oyster shell waste into high-purity calcium carbonate via CO₂ mineralization." Journal of CO₂ Utilization, 2024. ScienceDirect →
- Hong Y.-M., Choudhury S.R. "The Substitution Effect of the Fine Aggregate in Concrete with Oyster Shell." Materials, 2024, 17(24), 6148. DOI →
- Liao Y. et al. Reviews on the multi-purpose use of oyster shells (Han 2022 and others). [primary source being checked]
- Morris J.P. et al. "Shells from aquaculture: a valuable biomaterial, not a blue carbon sink." [primary source being checked]
- McCarthy A. et al. "Greenhouse gas emissions from bivalve aquaculture." 2019. [primary source being checked]
- Ahmad A. et al. "An overview of microalgae biomass as a sustainable aquaculture feed ingredient: food security and circular economy." Bioengineered, 2022, 13(4), 9521–9547. DOI →
- "Application of microalgae in wastewater treatment with special reference to emerging contaminants." Frontiers in Analytical Science, 2024. DOI →
- "Long-term oyster shell powder applications increase crop yields and control soil acidity and cadmium in red soil drylands." Frontiers in Plant Science, 2025. DOI →
- "Assessing the environmental and economic impacts of the oyster life cycle under renewable energy expansion." Journal of Environmental Management, 2025. ScienceDirect → [primary source being checked]
- Her S., Kim H., Naqi A. et al. Papers on oyster shell use as a construction material substitute. [primary source being checked]
- Fortune Business Insights. Microalgae Market Report, June 2025. [primary source being checked]
Note: references marked [primary source being checked] will be verified and updated before publication.
Joint research and partnership
Please get in touch below about demonstration partnerships, technology licensing or joint development around the biomass utilisation equipment. Detailed materials are available following an NDA.