Production Of Oleochemicals Research Articles

Efficient xylose utilization leads to highest lipid productivity in Candida tropicalis SY005 among six yeast strains grown in mixed sugar medium

Six local isolates of yeasts were screened for cell mass and lipid production in mixed glucose and xylose medium. Candida tropicalis SY005 and Trichosporon (Apiotrichum) loubieri SY006 showed significant lipid accumulation of 24.6% and 32% (dry cell weight), respectively when grown in medium containing equal mass of both the sugars. SY005 produced relatively higher cell mass of 9.66gL-1 due to higher rate of sugar consumption, which raised the lipid productivity of the organism to 0.792gL-1day-1 as compared to 0.446gL-1day-1 in SY006. When grown with each sugar separately, the xylose consumption rate of SY005 was found to be 0.55gL-1h-1 after 4days as compared to 0.52gL-1h-1 for SY006. Transcript expression of the high affinity xylose transporter (Cthaxt), xylose reductase (Ctxyl1), and xylitol dehydrogenase (Ctxyl2) of SY005 was monitored to unravel such high rate of sugar consumption. Expression of all the three genes was observed to vary in mixed sugars with Cthaxt exhibiting the highest expression in presence of only xylose. Expression levels of both Ctxyl1 and Ctxyl2, involved in xylose catabolism, were maximum during 24-48h of growth, indicating that xylose utilization started in the presence of glucose, which was depleted in the medium after 96h. Together, the present study documents that C. tropicalis SY005 consumes xylose concomitant to glucose during early period of growth, and it is a promising yeast strain for viable production of storage lipid or other high-value oleochemicals utilizing lignocellulose hydrolysate.

C/N ratio and carbon source-dependent lipid production profiling in Rhodotorula toruloides

Microbial oils are lipids produced by oleaginous microorganisms, which can be used as a potential feedstock for oleochemical production. The oleaginous yeast Rhodotorula toruloides can co-produce microbial oils and high-value compounds from low-cost substrates, such as xylose and acetic acid (from hemicellulosic hydrolysates) and raw glycerol (a byproduct of biodiesel production). One step towards economic viability is identifying the best conditions for lipid production, primarily the most suitable carbon-to-nitrogen ratio (C/N). Here, we aimed to identify the best conditions and cultivation mode for lipid production by R. toruloides using various low-cost substrates and a range of C/N ratios (60, 80, 100, and 120). Turbidostat mode was used to achieve a steady state at the maximal specific growth rate and to avoid continuously changing environmental conditions (i.e., C/N ratio) that inherently occur in batch mode. Regardless of the carbon source, higher C/N ratios increased lipid yields (up to 60% on xylose at a C/N of 120) but decreased the specific growth rate. Growth on glycerol resulted in the highest specific growth and lipid production (0.085 g lipids/gDW*h) rates at C/Ns between 60 and 100. We went on to study lipid production using glycerol in both batch and fed-batch modes, which resulted in lower specific lipid production rates compared with turbisdostat, however, fed batch is superior in terms of biomass production and lipid titers. By combining the data we obtained in these experiments with a genome-scale metabolic model of R. toruloides, we identified targets for improvements in lipid production that could be carried out either by metabolic engineering or process optimization.

Multidimensional engineering of Saccharomyces cerevisiae for efficient synthesis of medium-chain fatty acids

Medium-chain fatty acids (MCFAs; C6–C12) are valuable molecules used for biofuel and oleochemical production; however, it is challenging to synthesize these fatty acids efficiently using microbial biocatalysts due to the cellular toxicity of MCFAs. In this study, both the endogenous fatty acid synthase (FAS) and an orthogonal bacterial type I FAS were engineered for MCFA production in the yeast Saccharomyces cerevisiae. To improve cellular tolerance to toxic MCFAs, we performed directed evolution of the membrane transporter Tpo1 and strain adaptive laboratory evolution, which elevated the MCFA production by 1.3 ± 0.3- and 1.7 ± 0.2-fold, respectively. We therefore further engineered the highly resistant strain to augment the metabolic flux towards MCFAs. This multidimensional engineering of the yeast at the single protein/enzyme level, the pathway level and the cellular level, combined with an optimized cultivation process, resulted in the production of >1 g l−1 extracellular MCFAs—a more than 250-fold improvement over the original strain. Efficient microbial production of medium-chain fatty acids (MCFAs; C6–C12)—valuable molecules in the oleochemical and biofuel industry—is challenging due to their cellular toxicity. Now, this work improves the production of extracellular MCFAs to over 1 g l−1 by systematically engineering yeast at multiple levels.

Optimization Ratio of Mixed Metal Soaps (Al-Ca) and Palm Fatty Acid Distillate (PFAD) on Making Grease

Palm Fatty Acid Destilate (PFAD) to be used as a raw material for making oleochemical products, solid lubricant. This is caused by the composition of fatty acids contained in PFAD not much different from the composition of fatty acids found in palm oil. This study aims to determine the formulation of solid lubricants (grease) from PFAD and compound metal soap (Al-Ca) as thickener which has characteristics close to SNI solid lubricants and know the quality of solid lubricants produced. The method used in the manufacture of solid grease (grease) consists of two stages. The first stage is the process of making mixed metal soap (Al-Ca) by mixing PFAD and Al(OH)3-Ca(OH)2 and analyzing the mixed metal soap. The second stage is the manufacture of solid lubricants (grease) from mixed metal soap (Al-Ca) and PFAD as well as analyzing the resulting product.Based on the research that has been done, the optimum solid lubricant obtained according to SNI standards is in the composition of A:B1, A1 is the ratio of Al(OH)3:Ca(OH)2 = 90%:10% and B1 is the ratio of metal soap:PFAD = 90 %:10%, so the density is 0.95gr/ml and the penetration value is 194 (25 °C).

A novel electroporation procedure for highly efficient transformation of Lipomyces starkeyi

Microbial lipids produced by oleaginous microorganisms as raw materials for the production of oleochemicals and biodiesel are sustainable while avoiding competition with food products. The oleaginous yeast Lipomyces starkeyi is an excellent lipid producer with a great industrial potential that is suitable as a valuable host to improve lipid production through genetic engineering modifications. However, genetic tools, including effective transformation methods, for L. starkeyi are insufficient for improvement of lipid production and analysis of lipid production mechanisms. We previously developed a polyethylene glycol (PEG)-mediated spheroplast transformation method that significantly improved the homologous recombination efficiency of L. starkeyi strain ∆lslig4. Although other transformation methods, including lithium acetate (LiAc)-mediated transformation and Agrobacterium tumefaciens-mediated transformation, have been reported, a more efficient and convenient transformation method for L. starkeyi is desired. In this study, we developed a novel electroporation transformation method that was first applied for integration of drug-resistance gene markers into the genome of L. starkeyi strain ∆lslig4 at the 18S ribosomal DNA locus of a multiple-copy gene, which yielded approximately 60 transformants/μg of DNA. Optimization of five parameters (i.e., cell growth phase, cell density, osmotic stabilizers, pretreatment agents, and electric conditions) enhanced the efficiency of transformation to approximately 1.5 × 104 transformants/μg of DNA. As compared with those of LiAc-mediated transformation and PEG-mediated spheroplast transformation, the efficiency of the proposed transformation method was increased by about 111- and 7-fold, respectively. Additionally, the transformation efficiency of our proposed electroporation method targeting a single-copy gene locus yielded 273 transformants/μg of DNA. To our knowledge, this is the first report of a successful electroporation method to accelerate analysis of lipid production by L. starkeyi.

Optimization of protein isolation by proteomic qualification from Cutaneotrichosporon oleaginosus

In the last decades, microbial oils have been extensively investigated as a renewable platform for biofuel and oleochemical production. Offering a potent alternative to plant-based oils, oleaginous microorganisms have been the target of ongoing metabolic engineering aimed at increasing growth and lipid yields, in addition to specialty fatty acids. Discovery proteomics is an attractive tool for elucidating lipogenesis and identifying metabolic bottlenecks, feedback regulation, and competing biosynthetic pathways. One prominent microbial oil producer is Cutaneotrichosporon oleaginosus, due to its broad feedstock catabolism and high lipid yield. However, this yeast has a recalcitrant cell wall and high cell lipid content, which complicates efficient and unbiased protein extraction for downstream proteomic analysis. Optimization efforts of protein sample preparation from C. oleaginosus in the present study encompasses the comparison of 8 lysis methods, 13 extraction buffers, and 17 purification methods with respect to protein abundance, proteome coverage, applicability, and physiochemical properties (pI, MW, hydrophobicity in addition to COG, and GO analysis). The optimized protocol presented in this work entails a one-step extraction method utilizing an optimal lysis method (liquid homogenization), which is augmented with a superior extraction buffer (50 mM Tris, 8/2 M Urea/Thiourea, and 1% C7BzO), followed by either of 2 advantageous purification methods (hexane/ethanol or TCA/acetone), depending on subsequent applications and target studies. This work presents a significant step forward towards implementation of efficient C. oleaginosus proteome mining for the identification of potential targets for genetic optimization of this yeast to improve lipogenesis and production of specialty lipids.Graphical abstract

Assessment of heat pumping technology in oleochemical fatty acid fractionation

Similar to petroleum industry, major energy consumption in oleochemical plants is also dominated by separation process in order to obtain purified oleochemical cuts. Combination of the distillation column with heat pumping system has emerged as one of the most popular techniques in heat integration. Although heat pumping technology has been proven to be effective in petroleum separation, the research on this technology in oleochemical separation has not yet been discovered. Hence, it would be appealing to investigate the feasibility of integrating heat pump technology with distillation units in hopes of reducing energy usage in the separation of oleochemical products. In this study, two configurations of heat pumping system, namely direct vapor recompression (VRC) and bottom flashing heat pump (BFHP) are simulated in Aspen Plus particularly for fractionation of palm kernel oil (PKO) fatty acid. Proper selection of thermodynamic package is discussed in detail. Only three major components of PKO-based fatty acid are involved in the simulation in order to arrive at simple simulation and easy convergence. Simulation results indicates that both configurations of heat pump can be feasibly integrated with the distillation column. However, to satisfy the heating and cooling requirement, supply of makeup utility is necessary.

Heat Integration of a Boiler and Its Corresponding Environmental Study in an Oleochemical Production Plant: An Industry Case Study in Malaysia

The growing demands for oleochemical products are expected to reach approximately RM 157.59 billion by 2026 due to an increased drive from the food and beverages, chemicals, and pharmaceutical industries. However, this will lead to an increase in energy consumption and subsequent flue gas emission. Proper utilization of waste gas recovery systems is thus a major research area, focusing on reducing fuel consumption and emissions of greenhouse gases without affecting process performance. In this paper, a palm oil-based oleochemical plant is studied. The fuel consumption and emission of flue gas from a thermal oil boiler were measured and the feasibility of implementation of a waste heat recovery system and its environmental impact study. The results show that the implementation of such a system can reduce natural fuel gas consumption by 17.29% and approximately 149.29 t per annum of carbon dioxide gas (CO2). Moreover, the concentration of CO2 released into highly-populated communities is estimated through a Gaussian Plume Model at different wind speed conditions. The preliminary results show that the CO2 concentration at two locations—an apartment and a local school located within 1.5 km of the plant—is well below the concentration limit of 1.938 g/m3 recommended by the Wisconsin Department of Health and Services.

Engineering Escherichia coli FAB system using synthetic plant genes for the production of long chain fatty acids

BackgroundSustainable production of microbial fatty acids derivatives has the potential to replace petroleum based equivalents in the chemical, cosmetic and pharmaceutical industry. Most fatty acid sources for production oleochemicals are currently plant derived. However, utilization of these crops are associated with land use change and food competition. Microbial oils could be an alternative source of fatty acids, which circumvents the issue with agricultural competition.ResultsIn this study, we generated a chimeric microbial production system that features aspects of both prokaryotic and eukaryotic fatty acid biosynthetic pathways targeted towards the generation of long chain fatty acids. We redirected the type-II fatty acid biosynthetic pathway of Escherichia coli BL21 (DE3) strain by incorporating two homologues of the beta-ketoacyl-[acyl carrier protein] synthase I and II from the chloroplastic fatty acid biosynthetic pathway of Arabidopsis thaliana. The microbial clones harboring the heterologous pathway yielded 292 mg/g and 220 mg/g DCW for KAS I and KAS II harboring plasmids respectively. Surprisingly, beta-ketoacyl synthases KASI/II isolated from A. thaliana showed compatibility with the FAB pathway in E. coli.ConclusionThe efficiency of the heterologous plant enzymes supersedes the overexpression of the native enzyme in the E. coli production system, which leads to cell death in fabF overexpression and fabB deletion mutants. The utilization of our plasmid based system would allow generation of plant like fatty acids in E. coli and their subsequent chemical or enzymatic conversion to high end oleochemical products.

Genome-scale model of Rhodotorula toruloides metabolism.

The basidiomycete red yeast Rhodotorula toruloides is a promising platform organism for production of biooils. We present rhto-GEM, the first genome-scale model (GEM) of R. toruloides metabolism, that was largely reconstructed using RAVEN toolbox. The model includes 852 genes, 2,731 reactions, and 2,277 metabolites, while lipid metabolism is described using the SLIMEr formalism allowing direct integration of lipid class and acyl chain experimental distribution data. The simulation results confirmed that the R. toruloides model provides valid growth predictions on glucose, xylose, and glycerol, while prediction of genetic engineering targets to increase production of linolenic acid, triacylglycerols, and carotenoids identified genes-some of which have previously been engineered to successfully increase production. This renders rtho-GEM valuable for future studies to improve the production of other oleochemicals of industrial relevance including value-added fatty acids and carotenoids, in addition to facilitate system-wide omics-data analysis in R. toruloides. Expanding the portfolio of GEMs for lipid-accumulating fungi contributes to both understanding of metabolic mechanisms of the oleaginous phenotype but also uncover particularities of the lipid production machinery in R. toruloides.

Establishing CRISPR/Cas9 in Lipomyces starkeyi

The goal of this project was to adapt the Yarrowia lipolytica plasmid based CRISPR/Cas9 system for usage in Lipomyces starkeyi. Lipomyces starkeyi is an oleaginous yeast, which synthesizes and stores high amounts of intracellular lipids. This specific yeast can store lipids at concentrations higher than 60% of its dry cell weight. Due to these high concentrations of lipids, L. starkeyi is a desired organism for the production of biofuels and other oleochemicals. However, there is a lack of knowledge and of genetic tools when trying to engineer the cells to produce these lipids for our use. The genome editing tool, CRISPR/Cas9 is efficient and simple, therefore desirable for the engineering of L. starkeyi. The goal was achieved by replacing the Y. lipolytica promoter with a L. starkeyi promoter, inserting guide RNA, as well as confirming cas9 protein expression.

In silico identification of metabolic engineering strategies for improved lipid production in Yarrowia lipolytica by genome-scale metabolic modeling

BackgroundYarrowia lipolytica, an oleaginous yeast, is a promising platform strain for production of biofuels and oleochemicals as it can accumulate a high level of lipids in response to nitrogen limitation. Accordingly, many metabolic engineering efforts have been made to develop engineered strains of Y. lipolytica with higher lipid yields. Genome-scale model of metabolism (GEM) is a powerful tool for identifying novel genetic designs for metabolic engineering. Several GEMs for Y. lipolytica have recently been developed; however, not many applications of the GEMs have been reported for actual metabolic engineering of Y. lipolytica. The major obstacle impeding the application of Y. lipolytica GEMs is the lack of proper methods for predicting phenotypes of the cells in the nitrogen-limited condition, or more specifically in the stationary phase of a batch culture.ResultsIn this study, we showed that environmental version of minimization of metabolic adjustment (eMOMA) can be used for predicting metabolic flux distribution of Y. lipolytica under the nitrogen-limited condition and identifying metabolic engineering strategies to improve lipid production in Y. lipolytica. Several well-characterized overexpression targets, such as diglyceride acyltransferase, acetyl-CoA carboxylase, and stearoyl-CoA desaturase, were successfully rediscovered by our eMOMA-based design method, showing the relevance of prediction results. Interestingly, the eMOMA-based design method also suggested non-intuitive knockout targets, and we experimentally validated the prediction with a mutant lacking YALI0F30745g, one of the predicted targets involved in one-carbon/methionine metabolism. The mutant accumulated 45% more lipids compared to the wild-type.ConclusionThis study demonstrated that eMOMA is a powerful computational method for understanding and engineering the metabolism of Y. lipolytica and potentially other oleaginous microorganisms.

Metabolic traits specific for lipid-overproducing strain of Mucor circinelloides WJ11 identified by genome-scale modeling approach.

The genome-scale metabolic model of a lipid-overproducing strain of Mucor circinelloides WJ11 was developed. The model (iNI1159) contained 1,159 genes, 648 EC numbers, 1,537 metabolites, and 1,355 metabolic reactions, which were localized in different compartments of the cell. Using flux balance analysis (FBA), the iNI1159 model was validated by predicting the specific growth rate. The metabolic traits investigated by phenotypic phase plane analysis (PhPP) showed a relationship between the nutrient uptake rate, cell growth, and the triacylglycerol production rate, demonstrating the strength of the model. A putative set of metabolic reactions affecting the lipid-accumulation process was identified when the metabolic flux distributions under nitrogen-limited conditions were altered by performing fast flux variability analysis (fastFVA) and relative flux change. Comparative analysis of the metabolic models of the lipid-overproducing strain WJ11 (iNI1159) and the reference strain CBS277.49 (iWV1213) using both fastFVA and coordinate hit-and-run with rounding (CHRR) showed that the flux distributions between these two models were significantly different. Notably, a higher flux distribution through lipid metabolisms such as lanosterol, zymosterol, glycerolipid and fatty acids biosynthesis in iNI1159 was observed, leading to an increased lipid production when compared to iWV1213. In contrast, iWV1213 exhibited a higher flux distribution across carbohydrate and amino acid metabolisms and thus generated a high flux for biomass production. This study demonstrated that iNI1159 is an effective predictive tool for the pathway engineering of oleaginous strains for the production of diversified oleochemicals with industrial relevance.

Dynamic Data Sampling Approach by Using Price Distribution of Crude Palm Oil to Forecast High Magnitude Price Movement

Traditionally the chemical industry uses coal, minerals and petroleum as its basic raw materials, but palm oil and palm kernel oil are being increasingly used as economical raw materials especially for the production of oleochemicals. High magnitude palm oil price volatility in recently years has been a major challenge faced the industry. Though many time series models have been developed, few have wide adoption in the industry, and one of the key issues is the sampling interval used in the models. To date, little effort has been spent on mining historical data to determine the representativeness of interval sampling. This paper presents a novel approach in identifying price equilibrium for crude palm oil by mining the sampling amount through historical price distribution. Evaluation is done on the outcomes of the experiment, and analysis is performed on the attributes of each different criteria of the price distribution. The performance of the proposed approach is also compared to the conventional Bollinger Band with static sampling size. Overall, the preliminary results show that price distribution with leptokurtic distribution outperforms other price distribution patterns, this will definitely assist further works to devise a novel financial time series analysis technique.

Valorisation of sugarcane molasses for the production of microbial lipids via fermentation of two Rhodosporidium strains for enzymatic synthesis of polyol esters

AbstractBACKGROUNDBioprocess development for microbial oil production using cane sugar and sugarcane molasses via fermentation followed by enzymatic conversion into fatty acid esters is presented in this study.RESULTSMicrobial oil was initially evaluated in shake flask fermentations of Rhodosporidium toruloides NRRL Y‐27012 and R. kratochvilovae Y‐43 using either very high polarity (VHP) cane sugar or sugarcane molasses. Supplementation of phosphate salts, trace elements and nitrogen sources in molasses‐based cultures influenced yeast growth and microbial oil production. R. kratochvilovae had different nutrient requirements than R. toruloides. Fed‐batch bioreactor cultures of R. toruloides in molasses‐based cultures without any phosphate salts and trace element supplementation led to a microbial oil concentration of 25 g L−1 and an intracellular lipid content of 61% (w/w). Nutrient supplementation influenced the fatty acid composition of microbial oils indicating that enrichment in oleic acid could be achieved (up to 65.1%). The microbial oil produced by R. toruloides was enzymatically converted into polyol esters with a conversion yield of more than 85% (w/w).CONCLUSIONThis study demonstrates that Rhodosporidium sp. can be cultivated in molasses for the production of oleic acid enriched microbial lipids by adjusting medium composition. The polyol esters derived from microbial lipids could be used as a renewable feedstock for oleochemical production. © 2019 Society of Chemical Industry

Fatty Acid Direct Production from Palm Kernel Oil

Fatty acid is one of oleochemical products that can be obtained from palm kernel oil. The fatty acids can be produced enzymatically hydrolyzing palm oil by using lipase. This study aims to assess the conversion of palm kernel oil into fatty acids with activate lipase enzyme in palm kernel. Observation of this research consist of variety of duration of hydrolysis, the hydrolysis reaction temperature, and the addition of water. The highest percentage of fatty acid produced in this research is 34.645 %. This result obtained at 2 hours of hydrolysis reaction time and 40% of water addition at 35 °C, and the fatty acid produced in this study is dominated by lauric acid with a composition of 52.465%.

Evaluation of the efficacy of subcritical water to enhance the lipid fraction from activated sludge for biodiesel and oleochemicals production

AbstractActivated sludge is currently being investigated as a potential feedstock to produce biodiesel. Reports have shown that its lipid yield is usually low, compared to the commercially available feedstocks, such as soybean, sunflower, and rapeseed oils. The current work is geared toward investigating the potential of enhancing the total lipid yield (neutral and phospholipid) by the application of subcritical water. The results show that subcritical water treatment increased the total lipid yield by 145% at the optimum conditions 280°C, 40 min, 15 mL of water and biomass loading of 5%. The lipid classes identified were waxes, acylglycerol, sterol, free fatty acid, and phospholipids. The results of the fatty acid methyl esters analysis revealed palmitic acid as the predominant fatty acid.Practical applicationsThe practical applications of the results are informed from the improved lipid yield obtained, suggesting that subcritical water treatment is essential if activated sludge were to be a viable feedstock for biodiesel, renewable diesel, and oleochemicals productions. This will serve as a sustainable activated sludge disposal strategy.

Optimization of microwave-assisted solvent extraction of non-edible sandbox (Hura crepitans) seed oil: A potential biodiesel feedstock

In this study, modeling and optimization of the microwave-assisted solvent extraction (MASE) of sandbox seed oil (SSO) were investigated. D-optimal design with two numeric (extraction time (5–15 min), heating power (180–540 W)) and two categoric (solid/solvent ratio (1:10–1:40) and solvent type (ethyl acetate, n-hexane and acetone)) factors was used to model and optimize SSO yield. The model developed had coefficient of determination (R2) of 0.9821, indicating it can be used to adequately describe the MASE process with high accuracy. Optimum SSO yield of 72.20 ± 0.35 wt% could be obtained using extraction time of 5 min, microwave heating power of 180 W, solid/solvent ratio of 1:40 and ethyl acetate as solvent of extraction. Performance evaluation of the solvents in terms of oil yield showed that ethyl acetate was the most efficient (72.20 ± 0.35 wt%) followed by acetone (57.90 ± 1.27 wt%) and n-hexane (56.25 ± 1.77 wt%). Physicochemical properties of the SSO varied depending on the solvent of extraction. Fatty acids profile of the SSO showed that it had more unsaturated (79.7–84.5%) fractions than saturated (15.5–20.2%) fractions. Therefore, SSO could serve as feedstock for biodiesel and other oleochemical production.

Effects of overexpression of STB5 in Saccharomyces cerevisiae on fatty acid biosynthesis, physiology and transcriptome.

ABSTRACTMicrobial conversion of biomass to fatty acids (FA) and products derived thereof is an attractive alternative to the traditional oleochemical production route from animal and plant lipids. This study examined if NADPH-costly FA biosynthesis could be enhanced by overexpressing the transcription factor Stb5 in Saccharomyces cerevisiae. Stb5 activates expression of multiple genes encoding enzymes within the pentose phosphate pathway (PPP) and other NADPH-producing reactions. Overexpression of STB5 led to a decreased growth rate and an increased free fatty acid (FFA) production during growth on glucose. The improved FFA synthetic ability in the glucose phase was shown to be independent of flux through the oxidative PPP. RNAseq analysis revealed that STB5 overexpression had wide-ranging effects on the transcriptome in the batch phase, and appeared to cause a counterintuitive phenotype with reduced flux through the oxidative PPP. During glucose limitation, when an increased NADPH supply is likely less harmful, an overall induction of the proposed target genes of Stb5 (eg. GND1/2, TAL1, ALD6, YEF1) was observed. Taken together, the strategy of utilizing STB5 overexpression to increase NADPH supply for reductive biosynthesis is suggested to have potential in strains engineered to have strong ability to consume excess NADPH, alleviating a potential redox imbalance.

Environmental sustainability assessment of renewables‐based propylene glycol at full industrial scale production

AbstractBACKGROUNDGlycerol, a by‐product from oleochemical or biodiesel production, can be used to produce renewables‐based propylene glycol (PG). The environmental sustainability of PG was evaluated using life‐cycle assessment. The effect of shifting from petrochemical to renewables‐based PG was assessed by using data from an industrial scale renewables‐based PG production plant. A contribution analysis was performed to identify the hotspots in the production process. The effects of implementing a sustainable sourcing strategy and producing steam/electricity by combined heat and power (CHP) were assessed.RESULTSA switch from petrochemical to renewables‐based PG results in a reduction of the climate change impact between 40% and 60% kg CO2 eq. A shift of burden is found to agriculture‐related indicators. For the biodiesel and oleochemical production route, respectively, 73% and 59% of the impact on climate change is related to feedstock production. By implementing two improvements, the emitted CO2 eq. for biodiesel PG could be reduced by 38%.CONCLUSIONSSwitching from petrochemical to renewables‐based PG has a clear environmental benefit for slowing climate change. However, the shift of burden towards agriculture‐related indicators shows the need to ensure sustainable agricultural practices. Combining both on‐site improvements and a more sustainable supply chain effectively decreases the environmental impact. © 2019 Society of Chemical Industry