A New Wave of Industrialization of PHA Biopolyesters

Abstract

The ever-increasing use of plastics, their fossil origin, and especially their persistence in nature have started a wave of new innovations in materials that are renewable, offer the functionalities of plastics, and are biodegradable. One such class of biopolymers, polyhydroxyalkanoates (PHAs), are biosynthesized by numerous microorganisms through the conversion of carbon-rich renewable resources. PHA homo- and heteropolyesters are intracellular products of secondary microbial metabolism. When isolated from microbial biomass, PHA biopolymers mimic the functionalities of many of the top-selling plastics of petrochemical origin, but biodegrade in soil, freshwater, and marine environments, and are both industrial- and home-compostable. Only a handful of PHA biopolymers have been studied in-depth, and five of these reliably match the desired material properties of established fossil plastics. Realizing the positive attributes of PHA biopolymers, several established chemical companies and numerous start-ups, brand owners, and converters have begun to produce and use PHA in a variety of industrial and consumer applications, in what can be described as the emergence of the “PHA industry”. While this positive industrial and commercial relevance of PHA can hardly be described as the first wave in its commercial development, it is nonetheless a very serious one with over 25 companies and start-ups and 30+ brand owners announcing partnerships in PHA production and use. The combined product portfolio of the producing companies is restricted to five types of PHA, namely poly(3-hydroxybutyrate), poly(4-hydroxybutyrate), poly(3-hydroxybutyrate-co-3-hydroxyvalerate), poly(3-hydroxybutyrate-co-4-hydroxybutyrate), and poly(3-hydroxybutyrate-co-3-hydroxyhexanoate), even though PHAs as a class of polymers offer the potential to generate almost limitless combinations of polymers beneficial to humankind. To date, by varying the co-monomer type and content in these PHA biopolymers, their properties emulate those of the seven top-selling fossil plastics, representing 230 million t of annual plastics production. Capacity expansions of 1.5 million t over the next 5 years have been announced. Policymakers worldwide have taken notice and are encouraging industry to adopt biodegradable and compostable material solutions. This wave of commercialization of PHAs in single-use and in durable applications holds the potential to make the decisive quantum leap in reducing plastic pollution, the depletion of fossil resources, and the emission of greenhouse gases and thus fighting climate change. This review presents setbacks and success stories of the past 40 years and the current commercialization wave of PHA biopolymers, their properties, and their fields of application.

Advances in Polyhydroxyalkanoate (PHA) Production, Volume 3

“…However, the combined product portfolio of currently active PHA manufacturing companies is still limited to five major types of PHA, namely the homopolyesters P(3HB) and poly(4-hydroxybutyrate) (P(4HB)), and the copolyesters poly(3-hydroxybutyrate- co -3-hydroxyvalerate) (P(3HB- co -3HV)), poly(3-hydroxybutyrate- co -4-hydroxybutyrate) (P(3HB- co -4HB)), and poly(3HB- co -3HHx), while only one company produces mcl -PHA of different composition on a reasonable scale as contract work. Optimistic capacity enlargements from currently estimated 1.5 million t over the next five years have been announced by different companies [ 35 ]. It will be fascinating to see the de facto developments on the PHA market during the next few years, in particular whether these enthusiastic industrial announcements can keep up with the actual increases in production and capacity!…”

Degradation of P(3HB-co-4HB) Films in Simulated Body Fluids

“…With the reputation of being green polymers, polyhydroxyalkanoates (PHA) represent a very “hot” alternative to commercial polymers. PHA represents an extensive family of biopolymers, including homopolymers and copolymers, which are very diverse in monomer composition [ 1 ]. Unlike petrochemical polymers, PHA are entirely biodegradable and biocompatible.…”

A Review on Enhancing Cupriavidus necator Fermentation for Poly(3-hydroxybutyrate) (PHB) Production From Low-Cost Carbon Sources

“…Specifically, the PHB price ranges from 1.5 to 5.0 € per kg ( Chanprateep, 2010 ), while polypropylene price only ranges from 0.25 to 0.5 US$ per kg ( Khanna and Srivastava, 2005 ). The high production costs led to the fact that the commercial production of PHB had to be limited to small-scale plants with yields ranging from 1,000 to 20,000 metric tons per year ( Kosior et al, 2006 ; Koller and Mukherjee, 2022 ). Of the total production cost of PHB, the cost of raw materials (carbon sources) constitutes approximately 50–60% ( Nonato et al, 2001 ).…”