摘要:
A biocomposite is produced from natural fiber fabrics embedded in a matrix of biosynthetic polyhydroxy-alkanoate (PHA) polymers. The PHA is synthesized using aerobic microbial biosynthesis using mixed bacterial cultures and a feedstock containing anaerobic degradation products such as methane and volatile fatty acids derived from microbial biodegradation of organic waste materials, which may include waste biocomposites. Monomers may be added to the synthesized PHA polymer to control mechanical properties of the resulting biocomposite. The natural fibers and/or PHA may be pretreated using various techniques to improve the bond between the fibers and the PHA resin matrix and water absorption resistance of the fibers. The composite may be a laminate of treated and untreated fabric layers, or differently treated layers, to achieve good in-service performance as well as rapid and/or optimal biogas production when taken out of service and put in an anaerobic environment to degrade.
摘要:
A biocomposite is produced from natural fiber fabrics embedded in a matrix of biosynthetic polyhydroxy-alkanoate (PHA) polymers. The PHA is synthesized using aerobic microbial biosynthesis using mixed bacterial cultures and a feedstock containing anaerobic degradation products such as methane and volatile fatty acids derived from microbial biodegradation of organic waste materials, which may include waste biocomposites. Monomers may be added to the synthesized PHA polymer to control mechanical properties of the resulting biocomposite. The natural fibers and/or PHA may be pretreated using various techniques to improve the bond between the fibers and the PHA resin matrix and water absorption resistance of the fibers. The composite may be a laminate of treated and untreated fabric layers, or differently treated layers, to achieve good in-service performance as well as rapid and/or optimal biogas production when taken out of service and put in an anaerobic environment to degrade.
摘要:
A biocomposite is produced from natural fiber fabrics embedded in a matrix of biosynthetic polyhydroxy-alkanoate (PHA) polymers. The PHA is synthesized using aerobic microbial biosynthesis using mixed bacterial cultures and a feedstock containing anaerobic degradation products such as methane and volatile fatty acids derived from microbial biodegradation of organic waste materials, which may include waste biocomposites. Monomers may be added to the synthesized PHA polymer to control mechanical properties of the resulting biocomposite. The natural fibers and/or PHA may be pretreated using various techniques to improve the bond between the fibers and the PHA resin matrix and water absorption resistance of the fibers. The composite may be a laminate of treated and untreated fabric layers, or differently treated layers, to achieve good in-service performance as well as rapid and/or optimal biogas production when taken out of service and put in an anaerobic environment to degrade.
摘要:
Methods for producing bioplastics from biogas include techniques for the production of PHB using a dirty biogas (e.g., methane from landfill, digester) as both a power source for the process and as feedstock. Biogas is split into two streams, one for energy to drive the process, another as feedstock. Advantageously, the techniques may be implemented off the power grid with no dependence upon agricultural products for feedstock.
摘要:
Semicrystalline bioplastic materials are processed by thermally annealing the bioplastic to increase degree of crystallinity in the bioplastic; and anaerobically biodegrading the thermally annealed bioplastic. The thermal annealing may be performed using a commercial annealing oven. The anaerobic biodegradation may be performed in an anaerobic digester, a landfill, or other suitable environment.
摘要:
A method of biosynthesis of polyhydroxyalkanoates (PHA) is provided that includes providing a type II methanotrophic bacteria, and disposing the type II methanotrophic bacteria in an unbalanced growth condition, where the unbalanced growth condition includes a nutrient-deficient media and a hydroxyalkanoic acid, and where the nutrient-deficient media has an absence of an essential nutrient required for cell replication of the type II methanotrophic bacteria.
摘要:
A method for inexpensive and efficient PHA biosynthesis includes operating a sequencing bioreactor in alternating phases of nutrient deprivation and carbon feedstock deprivation to select for robust PHA-producing microbes. Preferably, the bioreactor is operated in a non-sterile manner with mixed cultures of methanotrophs. The method also preferably uses periodic biomass-wasting (PHA harvesting) at the end of the carbon feed phase, gradually lengthening the time period of carbon deprivation phase to create a penalty for rapid PHA degradation and incentive for PHA accumulation. Also, bacterial enrichment cultures may be introduced periodically. The PHA-accumulating bacteria are preferably grown on common anaerobic degradation products, specifically volatile fatty acids, such as acetate and propionate, and methane gas. The PHA has useful applications in bioplastics and other products.
摘要:
A method for inexpensive and efficient PHA biosynthesis includes operating a sequencing bioreactor in alternating phases of nutrient deprivation and carbon feedstock deprivation to select for robust PHA-producing microbes. Preferably, the bioreactor is operated in a non-sterile manner with mixed cultures of methanotrophs. The method also preferably uses periodic biomass-wasting (PHA harvesting) at the end of the carbon feed phase, gradually lengthening the time period of carbon deprivation phase to create a penalty for rapid PHA degradation and incentive for PHA accumulation. Also, bacterial enrichment cultures may be introduced periodically. The PHA-accumulating bacteria are preferably grown on common anaerobic degradation products, specifically volatile fatty acids, such as acetate and propionate, and methane gas. The PHA has useful applications in bioplastics and other products.
摘要:
A method of selection for type II methanotrophs is provided that includes enriching a microbial feedstock using a non-sterile bioreactor with a methane source and a nitrogen source, where the microbial feedstock includes a mixture of Type I and Type II methanotrophic cells, where an inhibited growth of the Type I methanotrophic cells and an enhanced growth of the Type II methanotrophic cells forms. The method further includes exposing intermittently the enriched microbial feedstock to i) nitrate, ii) urea, or i) and ii), where enhanced growth of the Type II methanotrophs is established, and exposing the Type II methanotrophs to an unbalanced growth condition where production of polyhydroxybutyrate is induced.
摘要:
Production of polyhydroxyalkanoates (PHAs) is performed by delivering substrates such as methane in gas phase during a high solids fermentation. Microorganisms are grown under balanced conditions, then gas phase substrates are delivered under unbalanced conditions to produce PHA granules inside the cells. The cells containing these granules are lysed and the bioplastic powder recovered. The balanced phase growth may occur in submerged liquid cultures or attached as biofilms to a surface.