The cultivation and development of uses for algae have exploded in the last decade. Support from process engineers like GEA is critical across diverse industries and today manufacturers can produce at industrial scale – efficiently and cost-effectively – thanks to advances in processing equipment and technical know-how.
Long esteemed around the world for its nutritional value and health benefits, algae are rich in polyunsaturated fatty acids, proteins, enzymes, vitamins, minerals and trace elements at high concentration. As a functional ingredient, it is sought after not only by the food, but also the feed industry. Algal oil, for example, is relieving some of the pressure on the global fish supply as it becomes more widely adopted in fishmeal; and some algae species are showing great promise in significantly reducing methane production when fed to cows. Toothpaste, cosmetics, biofuels, bio fertilizers and biopesticides – all are relevant applications in the pharma and chemical sectors. And because of their ability to bind heavy metals, algae are also effective in cleaning wastewater.
Thousands of microalgae species float in the world’s waters, capturing masses amount of carbon and releasing oxygen. This quality has led innovators to look for ways to further leverage these small powerhouses to increase carbon capture, even feeding industrial emissions into microalgae farms to speed up growth to promote more widespread algae usage as sustainable sources of energy or biodegradable plastics, for example.
Algae are further classified by size as either macro or micro, and by color, and are found in both marine and freshwater environments. Macroalgae include large aquatic plants, like kelp and seaweed varieties, some growing up to 50 meters long.
Microalgae, or phytoplankton, are single celled organisms, typically microscopic in size and have no roots, stems or leaves. They can be cultivated in photo-bioreactors (PBRs) or in open ponds and fed on wastewater, including sewage, or cultivated via heterotrophic fermentation, which means they are fed sugars instead of sunlight. Algae cultivation can take place on land unsuitable for conventional food crops, therefore it does not compete with food production.
With more than 50 years of algae processing experience, GEA has, and continues to be, an important partner for start-ups and industrial-scale algae producers, supporting them with know-how during the R&D phase and highly efficient processing technologies that meet strict industry standards. During processing, or harvesting, it is necessary to separate the algal biomass from the water it was grown, for which GEA has renowned technologies to handle concentrating, extracting, washing and drying algae suspensions.
Centrifugal technology is key given that centrifuges, sometimes called clarifiers or separators, are often the only economical method for efficiently processing microalgae, not only because they use less energy than ceramic membrane filtration, but also because the cell size of algae results in blockages in traditional rotatory vacuum filters. However, continuous centrifugation can make keeping algae cells alive a challenge as they are exposed to high shear force.
GEA has solved these challenges with its patented hydro-hermetic feed system and a hydro-brake assist ejection system solution for discharging extremely shear-sensitive cells from the centrifuge without damaging or destroying them – without which, mortality rates can reach more than 90 percent, even at reduced speeds.
Concentration, extraction & washing
GEA CIP-capable separators and decanters for separating liquid from alga biomass offer unique advantages for diverse algae types and cultivation conditions. Capacity, product viscosity, solids content and pH value in the fermentation broth and cell structure are used to define the right solution. In applications where greater concentration or dewatering is required, a decanter further reduces the liquid content of the algae biomass. A decanter can also sort and classify microalgae, for example when extracting pigments or colorants or health-promoting additives for food and feed.
For processing red and green microalgae, homogenization is the ideal method as this mechanical process breaks the outer cell wall, safely releasing the intracellular material, like proteins, enzymes or chlorophyll. GEA homogenizers ensure that algae material meets the quality required for foods as well as nutraceuticals, for example.
While centrifuges remove most of the free water from algae suspensions, several applications require algae powder, like supplements or feed additives, which necessitates spray drying. GEA spray dryers allow producers to control particle size distribution, moisture content, bulk density and particle shape, ensuring end customers receive algae powder that delivers precise and repeatable processing results.
Reducing energy consumption and operating costs are key to long-term success in the algae processing industry. We’re using our extensive experience and engineering know-how, to support customers and forming partnerships that bring algae-based products more efficiently to market for use by industry and consumers.
Our partnership began in 2015, helping the then bio-tech start-up with separation trials and developing a customized, scalable algae harvesting process. Utilizing a CIP-able GEA nozzle separator to achieve homogeneous algae concentrate with maximum dry matter and high separation efficiency, BIOREA is now producing at industrial scale, manufacturing high-quality biomass microalgae for use in food, feed and cosmetics.
OP Bio Factory researches and develops natural products from marine resources for use in drugs and other functional substances. With their conventional separator ejection system, 95 percent of their algae cells were being destroyed during discharge. In 2018, they introduced the GEA hydro brake assist feature to their separation process, reducing cell losses to just 2 percent, which has had a very positive impact on their costs and efficiency.
With GEA as its partner, Duplaco began producing and processing Chlorella microalgae first at laboratory-, then pilot- and now today at industrial scale, which it sells on in fresh or powder form to manufacturers for use in foods, such as baked goods, smoothies, vegan burgers, pasta, in food supplements and animal feed. GEA’s algae separation solutions ensure quality products with maximum consistency, while minimizing Duplaco’s energy costs and production footprint. This success has prompted them to purchase additional GEA equipment for the business, including various pumps, valves and cooling tanks.
An EU-funded initiative, GEA joined the SABANA team in 2016 to develop a large-scale, integrated microalgae-based biorefinery for the production of feed and feed additives, including biostimulants, biofertilizers and biopesticides. By demonstrating the technical, environmental and social feasibility of producing these valuable algae by-products using only marine water and wastewater as a nutrients source, the consortium aims to support more sustainable food production. To process the sensitive biomass, GEA has supplied expertise and equipment, including centrifuges for harvesting and concentrating the microalgae; homogenizers for cell disruption and a spray dryer for biomass drying so that the active agents can then be tested, the results of which will be available at the end of 2021.
Founder & Managing Director, Duplaco