Navigating the Drawbacks and Challenges of Bioenergy from Microalgae

One of the primary drawbacks of bioenergy from microalgae is the scalability and cost-effectiveness of production. While microalgae can be cultivated in various environments, including freshwater, seawater, and wastewater, scaling up production to meet commercial demands remains a significant challenge. The high costs associated with cultivating, harvesting, and processing microalgae biomass hinder the economic viability of large-scale bioenergy production.

In recent years, bioenergy derived from microalgae has emerged as a promising alternative to traditional fossil fuels, offering potential solutions to both energy security and environmental sustainability challenges. Microalgae possess several advantages, including high photosynthetic efficiency, rapid growth rates, and the ability to thrive in diverse environments. However, as with any emerging technology, there are significant drawbacks, failures, limitations, and challenges that must be navigated to realize the full potential of microalgae-based bioenergy.

Furthermore, despite advancements in cultivation techniques and genetic engineering, microalgae strains with high lipid content suitable for biofuel production remain difficult to find. Many microalgae species naturally produce low lipid yields, requiring extensive research and development efforts to enhance lipid accumulation through genetic manipulation or environmental stressors. Additionally, the competition between lipid accumulation and biomass productivity presents a trade-off that must be carefully balanced to maximize biofuel yields.

Another critical limitation of microalgae-based bioenergy is the energy-intensive processes involved in cultivation, harvesting, and conversion. The energy inputs required for maintaining optimal growth conditions, such as temperature, light intensity, and nutrient availability, often outweigh the energy outputs from biofuel production. This energy imbalance undermines the sustainability credentials of microalgae-based bioenergy and underscores the need for further innovation in process optimization and resource utilization.

Moreover, the environmental impacts of large-scale microalgae cultivation raise concerns regarding land and water use, nutrient pollution, and biodiversity loss. Intensive cultivation of microalgae in open ponds or bioreactors can lead to eutrophication of water bodies due to nutrient runoff and algal blooms, posing risks to aquatic ecosystems and human health. Additionally, land-use conflicts may arise from the conversion of natural habitats or agricultural land for microalgae cultivation, exacerbating deforestation and habitat destruction, just to cite a few.

Despite these challenges, researchers and industry stakeholders remain optimistic about the potential of microalgae-based bioenergy to contribute to a sustainable energy future. Ongoing research efforts focus on improving strain selection, cultivation methods, and downstream processing technologies to enhance the efficiency and scalability of biofuel production from microalgae. Advanced biorefinery concepts1, such as integrated systems for co-production of biofuels, bioproducts, and wastewater treatment, offer promising avenues for maximizing resource utilization and economic returns.

In conclusion, while bioenergy from microalgae holds great promise as a renewable and environmentally friendly energy source, it faces significant hurdles in terms of scalability, cost-effectiveness, and sustainability. Addressing these drawbacks and challenges will require interdisciplinary collaboration, innovative technologies, and supportive policy frameworks to unlock the full potential of microalgae-based bioenergy. By overcoming these obstacles, microalgae bioenergy could play a vital role in transitioning towards a more sustainable and resilient energy system.

  1. A novel process for enhancing oil production in algae biorefineries through bioconversion of solid by-products, https://doi.org/10.1016/j.biortech.2012.03.078 ↩︎

Job Research Internship BioRenewables

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Role Global challenges require global actions to achieve Sustainable Goals while supporting a circular economy. Biomass is a renewable versatile resource that can be used to produce heat, power, transport fuels and products, however, it should be sustainable. In an … Continue reading

Real-time monitoring of healthy omega-3 production in microalgae

A viability study

EPA and DHA. are essential fatty acids that humans need to live. Currently, they are usually obtained through fish oil, either from supplement or directly from oily fish. Unfortunately, fish farming is not sustainable and there is gathering interest in sourcing fatty acids from algae cells. The problem with algae growth comes from the varying lipid production per batch. Mid-production analysis is done on freeze dried samples after some time has passed, and fatty acid content cannot be measured until after the batch is complete. A real-time, on-line monitoring tool would greatly aid in algae production. Seven analytical techniques have been compared with Raman spectroscopy chosen as the most viable option to monitor omega-3 production in micro-algae.

Biomass Characterization by SEM-EDX

Climate change concerns and the post COVID world need urgent solutions to develop sustainable societies with better energy, products and services 1.

Biomass could help but its chemical properties must be known in faster ways2.

Our work delivered a faster and reliable method for elemental analyses of biomass with Scanning Electron Microscopy coupled to Energy Dispersive X-Ray Analysis.

1. United Nations (2015). Transforming Our World: the 2030 Agenda for Sustainable Development. [online] United Nations. (Accessed on 10 May 2023).

2. Biswas, B., Krishna, B. B., Kumar, M. K., Sukumaran, R. K. & Bhaskar, T. Chapter 7 – Biomass characterization. in Advanced Biofuel Technologies (eds. Tuli, D., Kasture, S. & Kuila, A.) 151–175 (Elsevier, 2022).

New Challenger for Sustainable Ethanol Production in Industrial Biorefineries

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Nations urgently need to tackle climate change in harmony with a circular economy to accomplish Sustainable Development Goals. Using sustainable biomass for sustainable industrial ethanol production seems attractive. Recently, the outstanding features of the arid plants nopales, aka prickly pear cactus, became headlines. Nopales outcompete algae and other biomasses in many aspects. Nopales are resilient, and climate change sparked their advancing invasion across European countries and other places.

Poster prickly pear cactus ethanol LCA
Poster presented at 7th Green and Sustainable Chemistry Conference, Dresden, Germany.

A sustainable biorefinery for ethanol production from nopales could holistically support promising outlooks on energy transition, water positive activities and food security near cities. However, the environmental impact and energy efficiency of this novel biorefinery for renewable energy under realistic scenarios is unknown. Traditional chemical pretreatments are polluters that can improve through environmental assessment and bio/chemical process design.  

We conducted experiments and assessments of scenarios for cleaner ethanol production from nopales in a biorefinery.  Four scenarios considered two fertilisers, two pretreatments and two operational modes. We conducted life cycle assessment, energy balances and energy efficiency calculations. The most polluting scenario uses fossil fertilisers, acid hydrolysis and neutralization of nopal nutrients, and it resulted in approximately four times the global warming potential of the best scenario.  Organic fertilisers and the use and reuse of ionic liquids with acetone for washing was the most ecofriendly scenario.

We propose a cleaner design showing the lowest impacts in all categories, including Global Warming, Acidification and Eutrophication Potentials and more. Besides, the design used the lowest amount of energy per unit of energy as ethanol fuel. It also has the best energy efficiency since it converted three-fold the amount of spent energy, in the worst scenario, into net energy as ethanol fuel.

Sustainable biorefineries and sustainable biomasses are opportunities in the circular economy while pursuing climate risk mitigation, carbon neutrality and green energy for sustainable development.