Introduction

The invention refers to a system for the selective transfer of volatile fatty acids (VFA) from an anaerobic fermenter into a polyhydroxyalkanoates (PHA) production system based on microbial mixed cultures (MMC). This system is able to produce a stable production of PHA containing bacteria.

Technical features

In order to obtain polyhydroxyalkanoates (PHA) being important biopolymers used increasingly throughout industries, VFAs can be produced from various fermentable waste. To date, many systems for extracting VFA from aqueous solutions, such as anionic exchange resins, are known. Nevertheless, obtaining VFAs in a usable form is more challenging as it requires higher thermal energy input or larger use of additional chemical reagents, such as  Sodium Hydroxide. The invention proposed overcomes the drawbacks of the currently existing  methods, through the use of a mixture of a very low toxicity (e.g. biodiesel or vegetable oils). It is also a closed system able both to reuse the recirculating solution and reduce consumption of the energy necessary for its operation.

Possible Applications

• Production of bioplastics;
• Biogas production systems;
• Treatment of wastewater;
• Treatment of agricultural and agro-industrial waste and residues.

Advantages

• Chemically safe system;
• Reduced operating costs;
• Minor capital investments;
• Increased process speed.