scholarly journals Development of Four Unit Processes for Biobased PLA Manufacturing

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Chae Hwan Hong ◽  
Si Hwan Kim ◽  
Ji-Yeon Seo ◽  
Do Suck Han
Keyword(s):  
Lactic Acid ◽  
Ring Opening ◽  
Lactic Acid Production ◽  
Scale Up ◽  
Catalyst System ◽  
Ring Opening Polymerization ◽  
Acid Fermentation ◽  
Manufacturing Method ◽  
Renewable Biomass ◽  
Microbial Productivity

Polylactide (PLA), which is one of the most important biocompatible polyesters that are derived from annually renewable biomass such as corn and sugar beets, has attracted much attention for automotive parts application. The manufacturing method of PLA is the ring-opening polymerization of the dimeric cyclic ester of lactic acid, lactide. For the stereocomplex PLA, we developed the four unit processes, fermentation, separation, lactide conversion, and polymerization. Fermentation of sugars to D-lactic acid is little studied, and its microbial productivity is not well known. Therefore, we investigated D-lactic acid fermentation with a view to obtaining the strains capable of producing D-lactic acid, and we got a maximum lactic acid production 60 g/L. Lactide is prepared by a two-step process: first, the lactic acid is converted into oligo(lactic acid) by a polycondensation reaction; second, the oligo(lactic acid) is thermally depolymerized to form the cyclic lactide via an unzipping mechanism. Through catalyst screening test for polycondensation and depolymerization reactions, we got a new method which shortens the whole reaction time 50% the level of the conventional method. Poly(L-lactide) was obtained from the ring-opening polymerization of L-lactide. We investigated various catalysts and polymerization conditions. Finally, we got the best catalyst system and the scale-up technology.

scholarly journals Statistical Optimization of Alkali Pretreatment to Improve Sugars Recovery from Spent Coffee Grounds and Utilization in Lactic Acid Fermentation

Processes ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 494 ◽  
Author(s):  
Kang Hyun Lee ◽  
Ye Won Jang ◽  
Jeongho Lee ◽  
Seunghee Kim ◽  
Chulhwan Park ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Enzymatic Hydrolysis ◽  
Lactic Acid Production ◽  
Complex Loading ◽  
Lactic Acid Fermentation ◽  
Optimum Conditions ◽  
Spent Coffee Grounds ◽  
Alkali Pretreatment ◽  
Acid Fermentation ◽  
Coffee Grounds

Biorefinery, which utilizes carbon-neutral biomass as a resource, is attracting attention as a significant alternative in a modern society confronted with climate change. In this study, spent coffee grounds (SCGs) were used as the feedstock for lactic acid fermentation. In order to improve sugar conversion, alkali pretreatment was optimized by a statistical method, namely response surface methodology (RSM). The optimum conditions for the alkali pretreatment of SCGs were determined as follows: 75 °C, 3% potassium hydroxide (KOH) and a time of 2.8 h. The optimum conditions for enzymatic hydrolysis of pretreated SCGs were determined as follows: enzyme complex loading of 30-unit cellulase, 15-unit cellobiase and 50-unit mannanase per g biomass and a reaction time of 96 h. SCG hydrolysates were used as the carbon source for Lactobacillus cultivation, and the conversions of lactic acid by L. brevis ATCC 8287 and L. parabuchneri ATCC 49374 were 40.1% and 55.8%, respectively. Finally, the maximum lactic acid production by L. parabuchneri ATCC 49374 was estimated to be 101.2 g based on 1000 g of SCGs through the optimization of alkali pretreatment and enzymatic hydrolysis.

scholarly journals Synthesis and Characterization of Polyphosphazenes Modified with Hydroxyethyl Methacrylate and Lactic Acid

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Evelyn Carolina Martínez Ceballos ◽  
Ricardo Vera Graziano ◽  
Gonzalo Martínez Barrera ◽  
Oscar Olea Mejía
Keyword(s):  
Lactic Acid ◽  
Ring Opening ◽  
Room Temperature ◽  
Block Structure ◽  
Ring Opening Polymerization ◽  
Synthesis And Characterization ◽  
Poly Lactic Acid ◽  
Hydroxyethyl Methacrylate ◽  
H Nmr

Poly(dichlorophosphazene) was prepared by melt ring-opening polymerization of the hexachlorocyclotriphosphazene. Poly[bis(2-hydroxyethyl-methacrylate)-phosphazene] and poly[(2-hydroxyethyl-methacrylate)-graft-poly(lactic-acid)-phosphazene] were obtained by nucleophilic condensation reactions at different concentrations of the substituents. The properties of the synthesized copolymers were assessed by FTIR,1H-NMR and31P-NMR, thermal analysis (DSC-TGA), and electron microscopy (SEM). The copolymers have a block structure and show twoTg's below room temperature. They are stable up to a temperature of 100°C. The type of the substituents attached to the PZ backbone determines the morphology of the polymers.

scholarly journals A Process Study of Lactic Acid Production from Phragmites australis Straw by a Thermophilic Bacillus coagulans Strain under Non-Sterilized Conditions

Processes ◽  
2018 ◽  
Vol 6 (10) ◽  
pp. 175 ◽  
Author(s):  
Yuming Zhang ◽  
Mengran Li ◽  
Tian Nie ◽  
Zhihua Ni
Keyword(s):  
Lactic Acid ◽  
Phragmites Australis ◽  
Lactic Acid Production ◽  
Scale Up ◽  
Bacillus Coagulans ◽  
Dilute Acid Pretreatment ◽  
Integrated Process ◽  
Dilute Acid ◽  
Acid Pretreatment ◽  
Process Study

Phragmites australis straw (PAS) is an abundant and renewable wetland lignocellulose. Bacillus coagulans IPE22 is a robust thermophilic strain with pentose-utilizing capability and excellent resistance to growth inhibitors. This work is focused on the process study of lactic acid (LA) production from P. australis lignocellulose which has not been attempted previously. By virtue of thermophilic feature of strain IPE22, two fermentation processes (i.e., separated process and integrated process), were developed and compared under non-sterilized conditions. The integrated process combined dilute-acid pretreatment, hemicellulosic hydrolysates fermentation, and cellulose utilization. Sugars derived from hemicellulosic hydrolysates and cellulose enzymatic hydrolysis were efficiently fermented to LA in a single vessel. Using the integrated process, 41.06 g LA was produced from 100 g dry PAS. The established integrated process results in great savings in terms of time and labor, and the fermentation process under non-sterilized conditions is easy to scale up for economical production of lactic acid from PAS.

Biometal Derivatives as Catalysts for the Ring-Opening Polymerization of Trimethylene Carbonate. Optimization of the Ca(II) Salen Catalyst System

2006 ◽  
Vol 39 (13) ◽  
pp. 4374-4379 ◽  
Author(s):  
Donald J. Darensbourg ◽  
Wonsook Choi ◽  
Poulomi Ganguly ◽  
Casseday P. Richers
Keyword(s):  
Ring Opening ◽  
Catalyst System ◽  
Ring Opening Polymerization ◽  
Trimethylene Carbonate

scholarly journals Recycling Of Peneapple Waste Using Lactobacillus Delbroeckii to Lactic Acid

REAKTOR ◽  
2017 ◽  
Vol 5 (2) ◽  
pp. 79
Author(s):  
Abdullah Abdullah ◽  
H. B. Mat
Keyword(s):  
Lactic Acid ◽  
Yeast Extract ◽  
Lactic Acid Production ◽  
Lactobacillus Delbrueckii ◽  
Raw Material ◽  
Acid Fermentation ◽  
Fermentation Time ◽  
Pineapple Waste ◽  
Fermentation Liquid ◽  
Initial Ph

The liquid pineapple waste contain mainly sucrose, glucose, fructose, and other nutrients. It therefore can potentiall be used as carbon source for organic acid fermentation. Recently, lactic acid has been considered to be an important raw material for production of biodegradadable lactace polymer. The experiments weree carried out in shake flash fermentation using lactobacillus delbroeckii. Effect of some parameters such as temperature, initial Ph, initial substrate concentration, yeast extract concentration and fermentation time to the yield have been studied. The highest yield was 85.65% achieved at 40 0C, PH 6.00, 52.2 g/l sugar concentration with 5 g/l yeast extract. There was no significant increasing in lactic acid production was observed if supplementation of yeast extract above 10%.Keyword : lactic acid fermentation, liquid pineapple waste, lactobacillus delbrueckii

scholarly journals Synthesis of lactic acid from sugar palm trunk waste (Arenga pinnata): Preliminary hydrolysis and fermentation studies

2020 ◽  
Vol 21 (5) ◽  
Author(s):  
WHINY HARDIYATI ERLIANA ◽  
Tri Widjaja ◽  
ALI ALTWAY ◽  
LILY PUDJIASTUTI
Keyword(s):  
Lactic Acid ◽  
Lignin Content ◽  
Agricultural Waste ◽  
Lactic Acid Production ◽  
Lactobacillus Rhamnosus ◽  
Lactobacillus Brevis ◽  
Reducing Sugar ◽  
Cellulose Content ◽  
Acid Pretreatment ◽  
Acid Fermentation

Abstract. Erliana WH, Widjaja T, Altway A, Pudjiastuti L. 2020. Synthesis of lactic acid from sugar palm trunk waste (Arenga pinnata): Hydrolysis and fermentation studies. Biodiversitas 21: 2281-2288. The increasing problems of global energy and the environment are the main reasons for developing products with new techniques through green methods. Sugar palm trunk waste (SPTW) has potential as agricultural waste because of its abundant availability, but it is not used optimally. This study was aimed to determine the effect of various microorganisms on increasing lactic acid production by controlling pH and temperature conditions in the fermentation process. SPTW contains 43.88% cellulose, 7.24% hemicellulose, and 33.24% lignin. The lignin content in SPTW can inhibit reducing sugar formation; the pretreatment process should remove this content. In the study, the pretreatment process was conducted using acid-organosolv. In the acid pretreatment, 0.2 M H2SO4 was added at 120oC for 40 minutes; organosolv pretreatment using 30% ethanol (v/v) at 107oC for 33 minutes was able to increase cellulose content by 56.33% and decrease lignin content by 27.09%. The pretreatment was followed by an enzymatic hydrolysis process with a combination of commercial cellulase enzymes from Aspergillus niger (AN) and Trichoderma reesei (TR), with variations of 0:1, 1:0, 1:1, 1:2 and 2:1. The best reducing sugar concentration was obtained with an AN: TR ratio of 1:2 to form reducing sugar from cellulose. Subsequently, lactic acid fermentation was carried out using lactic acid bacteria at 37oC and pH 6 incubated for 48 hours. The highest lactic acid concentration (33.292 g/L) was obtained using a mixed culture of Lactobacillus rhamnosus and Lactobacillus brevis to convert reducing sugar become lactic acid.

scholarly journals Simultaneous saccharification and lactic acid fermentation of the cellulosic fraction of municipal solid waste using Bacillus smithii

2020 ◽  
Author(s):  
Micaela G. Chacón ◽  
Christopher Ibenegbu ◽  
David J. Leak
Keyword(s):  
Lactic Acid ◽  
Municipal Solid Waste ◽  
Solid Waste ◽  
Lactic Acid Production ◽  
Lactic Acid Fermentation ◽  
Potential Candidate ◽  
Acid Fermentation ◽  
Promising Candidate ◽  
Cellulosic Pulp ◽  
Simultaneous Saccharification

Abstract Objective A primary drawback to simultaneous saccharification and fermentation (SSF) processes is the incompatibility of the temperature and pH optima for the hydrolysis and fermentation steps—with the former working best at 50–55 °C and pH 4.5–5.5. Here, nine thermophilic Bacillus and Parageobacillus spp. were evaluated for growth and lactic acid fermentation at high temperature and low pH. The most promising candidate was then carried forward to demonstrate SSF using the cellulosic fraction from municipal solid waste (MSW) as a feedstock. Results B. smithii SA8Eth was identified as the most promising candidate and in a batch SSF maintained at 55 °C and pH 5.0, using a cellulase dose of 5 FPU/g glucan, it produced 5.1 g/L lactic acid from 2% (w/v) MSW cellulosic pulp in TSB media. Conclusion This work has both scientific and industrial relevance, as it evaluates a number of previously untrialled bacterial hosts for their compatibility with lignocellulosic SSF for lactic acid production and successfully identifies B. smithii as a potential candidate for such a process.

Construction of polyphosphoesters with the main chain of rigid backbones and stereostructures via organocatalyzed ring-opening polymerization

2020 ◽  
Vol 11 (20) ◽  
pp. 3475-3480
Author(s):  
Yu-Jia Zheng ◽  
Guan-Wen Yang ◽  
Bo Li ◽  
Guang-Peng Wu
Keyword(s):  
Ring Opening ◽  
Main Chain ◽  
Catalyst System ◽  
Ring Opening Polymerization ◽  
System P ◽  
Organic Catalyst

A highly stereoregular polyphosphoester with a rigid cyclohexylene structure in the main chain was constructed via ring-opening polymerization (ROP) in the presence of an organic catalyst system.

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