Axel Barrett Feedstock Seaweed and Algae

Bioplastic Feedstock 1st, 2nd and 3rd Generations

A Summary of Bioplastics Feedstock

First Generation Feedstock

The first generation Feedstock were the first crops and plants used to produce bioplastics. They’re rich in carbohydrate and can be consumed by humans and animals. First generation feedstock are the most efficient to produce bioplastics as they require less land to grow, and have a higher yield and “efficiency” than other feedstock generations.

We measure the efficiency of the crop-bioplastic relationship through following criteria: the annual carbohydrate yield per hectare and land used per ton of bioplastics. R&D and new production processes may improve the efficiency of a crop in the future.

Examples of first generation feedstock: corn, wheat, sugarcane, potato, sugar beet, rice and plant oil.

There’s a criticism towards first generation feedstock because of its potential competition with food and animal feed. In other words, they take away food destined for human or animal consumption. Media headlines were linking the rise of large biofuel plantations with rising food prices; the “Food vs Fuel” debate. The second generation feedstock was a solution to this polemic.

This criticism was more aimed at the bio-fuels sector than the bioplastics sector, but there seem to be an assumptive association between bio-fuels and bio-plastics. Not truly justified. However, the division of feedstock into 1st, 2nd and 3rd generation in the bioplastics sector was inspired and driven by the evolution in the biofuels sector.

Second Generation Feedstock

Second generation feedstock refers to crops and plants not suitable for human consumption (food) or animal consumption (feed). Second generation feedstock can be either non-food crops (cellulosic feedstock) or waste materials from 1st generation feedstock (e.g. waste vegetable oil).

Examples of second generation feedstock include: wood, short-rotation crops such as poplar, willow or miscanthus (elephant grass), wheat straw, bagasse, corncobs, palm fruit bunches and switch grass.

The “Food vs Fuel” polemic continued for non-food crops if grown on land destined for food production. The use of agricultural waste or residues would not constitute a direct conflict with food unless they’re residues from the first generation feedstock. Straw could eventually be considered as animal feed and part of the food chain.

Third Generation Feedstock

Third generation feedstock is biomass derived from algae.  There’s a difference between algae and seaweed:

  • Seaweeds are a group of algae
  • Diversity of algae is extremely high and incomparable with that of seaweeds.
  • Algae can be unicellular and multi-cellular, whereas seaweeds are only multi-cellular.
  • Seaweed are autotrophic, whereas some algal species rely on other external food materials.
  • Algae can be found in freshwater and marine waters, while seaweeds can only be found in seawaters.
  • Marine algae can live in shallow and deep waters, while seaweeds mostly inhabit shallow waters

Algae have a higher yield or efficiency than 1st and 2nd generation feedstock. They don’t need fertilisers, pesticides, herbicides or land. Seaweed bioplastics biodegrades within 12 weeks in soil and 5 hours in water. It may be that algae bioplastics will disrupt the bioplastics industry. The problems is that algae bioplastics is more expensive than traditional plastics.