Conversion Of By-products Research Articles

Green process prorogue by xylanase enzyme and cellulose-derived sulfonated graphene oxide-like reinforcement in xylose and furfural production from corncob biomass

In this study, a process following the principles of green chemistry was applied for effective agricultural by-product conversion into biochemicals. Corncob was synergistically pretreated with a mixture of hydrogen peroxide:glacial acetic acid (1:2:2 wt/v/v) which was denoted as C-HPAC and then xylanase enzyme-assisted hydrolysis to obtain the highest xylose content of 1.99g with 66.41 % separation efficiency at 50 °C for 15h, and xylanase enzyme content of 0.4g/3g C-HPAC. Otherwise, the sulfonated graphene oxide-like structural material (EC-SGO) was synthesized through the sulfonation method using various concentrations of H2SO4 agent with EC-GO that was calcined with the mixture of ferrocene and cellulose (1:1 wt/wt) at 300 °C for 30 min. The highest furfural yield was 76.63 ± 2.23 % under the conditions of 60 mg EC-SGO catalyst, xylose concentration of 3 g/L, and NaCl 0.05 mol/L, at 180 °C in 60 min. Hence, the synergistic effect of NaCl and Brønsted acid sites (−SO3H) was confirmed through the XPS spectrum with an acid content of 0.6895 mmol/gcatalyst and depicted simultaneously a vital role through the proposal mechanism of converting xylose to furfural. The synthesized catalyst retains its stability for the multiple cycles of furfural production. Furthermore, this work has provided a route for the fractional separation of xylose and cellulose with assisted-enzymatic.

High H2 selective performance of Ni-Fe-Ca/H-Al catalysts for steam reforming of biomass and plastic

The development of a selective catalyst for the conversion of biomass and plastics into H2 by steam reforming can combat the energy crisis and global warming. In this work, support Ni-Fe-Ca/H-Al bifunctional catalysts were prepared by loading Ni and Fe into pretreatment CaO/Al2O3 (Ca/H-Al) carriers and showed high catalytic activity for the steam reforming of biomass and plastic. Moreover, the idea of bidirectional degradation was exploited to strengthen the pyrolysis of plastic with a high H/C and biomass with a high O/C. Interestingly, the products presented high H2 selective (1302.10 mL/g) and low CO2 yield (120.23 mL/g) in 7Ni-5Fe-Ca/H-Al(2:4) catalyst compared with current reports. Here, the abundant oxygen vacancies (Ov) in the H-Al carrier exhibited an electron-deficient nature, providing active sites for anchoring NiO. Meanwhile, NiO interacted with Ca2Fe2O5 to produce more defective Ov sites, which stabilized the NiO particles in the 7Ni-5Fe-Ca/H-Al (2:4) catalyst, and the interaction between the catalyst and the carrier was enhanced, leading to the reduction of weakly basic sites, this property promoted the strong adsorption of CO2 and H2O by the catalyst, contributing to the enhancement of efficient steam conversion and the promotion of conversion of by-products to H2. Notably, 7Ni-5Fe-Ca/H-Al(2:4) catalysts maintained structural integrity after regeneration and exhibited excellent regenerability in H2 selection and CO2 adsorption. The work provides a new idea for the study of efficient H2 production from steam reforming of biomass and plastics.

Conversion of by-products of alcohol production to produce isobutanol

Intensive research is underway in all developed countries to create an economical process for the production of butanol and its derivatives from biomass, which reduces the cost of the product compared to existing processes for producing synthetic butanol based on fossil raw materials. This is primarily due to the prospects of using butanol and its derivatives as an alternative fuel. The paper proposes a technology for the production of isobutyl alcohol, which provides for the processing of by-products of alcohol production by hydrogenation of crotonaldehyde. A concentrate of ethyl alcohol head fractions (KGF) and a concentrate of ethyl alcohol head fractions (KGF) were used as objects of research. In the process of work, a technology for processing by-products of alcohol production is proposed, which includes a number of stages with the production of isobutyl alcohol as a finished product, which can be used in the production of plastics, rubber, coatings, medicine and the production of special solvents, as well as as an additive to fuel. Experimental studies were conducted to obtain isobutanol and study its physicochemical properties: color, density; mass fraction of isobutyl alcohol, mass fraction of acids in terms of acetic acid, bromine number, mass fraction of carbonyl compounds in terms of oil aldehyde, mass fraction of non-volatile residue. The technological process at the isobutanol production plant is differentiated by stages, which are carried out sequentially in separate reactors with the treatment of intermediates with catalysts. As a result of the developed technology, butyl alcohol with a mass fraction of isobutyl alcohol of at least 99.3% was obtained.

Application of Aspergillus niger in Practical Biotechnology of Industrial Recovery of Potato Starch By-Products and Its Flocculation Characteristics

This study developed a practical recovery for potato starch by-products by A. niger and applied it on a plant scale to completely solve the pollution problems. Soughing to evaluate the effect of A. niger applied towards the production of by-products recycling and analyze the composition and characteristics of flocculating substances (FS) by A. niger and advance a possible flocculation mechanism for by-product conversion. After fermentation, the chemical oxygen demand (COD) removal rate, and the conversion rates of cellulose, hemicellulose, pectin, and proteins were 58.85%, 40.19%, 53.29%, 50.14%, and 37.09%, respectively. FS was predominantly composed of proteins (45.55%, w/w) and polysaccharides (28.07%, w/w), with two molecular weight distributions of 7.3792 × 106 Da and 1.7741 × 106 Da and temperature sensitivity. Flocculation was mainly through bridging and ionic bonding, furthermore, sweeping effects may occur during sediment. Flocculation was related to by-products conversion. However, due to severe pollution problems and resource waste, and deficiencies of existing recovery technologies, converting potato starch by-products via A. niger liquid fermentation merits significant consideration.

Xylitol and ethanol co-production from sugarcane bagasse and straw hemicellulosic hydrolysate supplemented with molasses

Co-production systems are a strategy used to diversify production chains and to enable more profitable processes. In addition, the valorization of the sugar-and-alcohol industry through by-product conversion into value-added products is environmentally friendly and enhances their competitiveness to other products available in the market. Thus, the aim of the current study is to evaluate xylitol and ethanol co-production by Candida tropicalis deriving from sugarcane by-products, such as bagasse and straw, supplemented with molasses. Sugarcane bagasse and straw hemicellulosic hydrolysate was obtained through dilute-acid hydrolysis with H2SO4; next, it was concentrated and detoxified with activated charcoal. Different commercial sucrose concentrations (5, 25 and 50 gL−1) were added to the bagasse and straw hemicellulosic hydrolysate in semi-defined medium. In addition, hydrolysate supplementation with sugarcane molasses was evaluated based on sucrose content (10 and 50 gL−1) adjustment. Batch fermentations were carried out in 125-mL Erlenmeyer flasks filled with 50 mL of medium, at 30 °C, 200 rpm, pH 5.5, for 48 h. Molasses supplementation adjusted to 50 gL−1 sucrose in sugarcane bagasse and straw hemicellulosic hydrolysate recorded the maximum xylitol (30.61 gL−1) and ethanol (47.97 gL−1) concentrations observed in the current study. Besides, volumetric xylitol (0.64 gL−1h−1) and ethanol (1.00 gL−1h−1) productivity was observed under the very same condition. Results have shown the likelihood of co-producing xylitol and ethanol through C. tropicalis by using sugarcane by-products to compose the fermentation medium as strategy to intensify and integrate these bioprocesses in sugarcane biorefineries.

Influence of the yeast aeration method on the quality characteristics of beer

Aeration of wort in brewing, as a traditional way to reduce the need for yeast oxygen, has several disadvantages associated with a change in the quality of the finished beverage. Another approach to solving this problem is the pre-fermentation preparation of brewer’s yeast, which consists in short-term aeration (30 min) of the inoculum followed by exposure without air for 2 hours. The effect of various methods of supplying the yeast culture with atmospheric oxygen on the formation of flavoring substances and change in physicochemical characteristics of beer. Objects of research are bottom fermentation yeast Saccharomyces cerevisiae, young and finished beer. It was revealed that in young beer fermented with yeast after aeration, the content of sensory significant components (higher alcohols, acetaldehyde, diacetyl) is on average 27% lower than in the variant with wort aeration. A possible reason for this is the high activity in the prepared inoculum in comparison with the initial culture of enzymes (1.7-1.8 times increased) involved in the conversion of by-products. Stimulation of the metabolic processes of yeast with oxygen, especially in the sample with aeration of the wort, creates the conditions for reducing (from 7 to 23%) the main mutating components. However, pre-aeration of the inoculum allows you to get a ready drink with the best taste and aromatic characteristics, which is the advantage of this method in comparison with aeration of the wort.

A promising approach to transform levulinic acid into γ-valerolactone using niobic acid photocatalyst and the accumulated electron transfer technique

The photocatalytic production of γ-valerolactone (GVL) from levulinic acid (LA) was performed using the UV-assisted accumulated electron transfer technique. For this purpose, a commercial niobic acid (HY-340) produced by Companhia Brasileira Metalurgia e Mineralurgia (CBMM) was used as photocatalyst. HY-340 showed higher efficiency in ethanol (a hole scavenger) and additional contact time with the substrate (48 h in the dark) after the reaction under UV light. Longer illumination time leads to the conversion of by-products to GVL with maximum selectivity of 44.7 %. Electron paramagnetic resonance (EPR) measurements allied with the spin trapping method indicated the reduction process occurs through the transfer of H•. Finally, O2 pulse titration was developed to quantify the electrons accumulated in the HY-340 conduction band. From this experiment, a significant TOF value was calculated to 3.3 × 10−6 s-1 considering that experiments were conducted at room temperature and ambient pressure.

Field of the secondary raw materials applicationof animal husbandry in the economic turnover

The current level of development of the domestic meat industry of the agro-industrial complex requires a fundamentally new approach to the problem of integrated use of all types of livestock products. In this regard, the utilization of by-products obtained during the slaughter of livestock, instead of its full and deep processing - not only the loss of valuable food and feed protein, but also huge monetary losses, leading to an increase in the cost of the main product - meat. The essence of an effective approach to the processing of slaughter products is to create and implement low-and waste-free technologies that allow you to maximize and comprehensively extract all the valuable components of raw materials, turning them into useful products. The researchers concluded that the livestock sector in Kazakhstan should be considered not only as a supplier of meat and dairy products, but also as a promising sub-sector that provides secondary raw materials to such industries as light, textile, construction, engineering and others. The categories of livestock slaughter products, the structure of its average standard output, and the main functions of waste-free production are considered. The features of development of deep processing of livestock products in Kazakhstan are analyzed and the directions of development of the meat industry are developed. The authors came to the conclusion that the economic efficiency of the meat industry depends on the rational use of all resources obtained during the slaughter of livestock and the conversion of by-products into marketable products.

MgxAl-LDHs layered double hydroxides catalysts for boosting catalytic synthesis of biodiesel and conversion of by-product into valuable glycerol carbonate

Abstract A series of layered double hydroxides (MgxAl-LDHs) catalysts is successfully prepared and effectively transesterificated triglycerides to produce biodiesel and glycerol carbonate, respectively. MgxAl-LDHs catalysts are synthesized by changing the Mg/Al ratio of the LDH hosts and fully characterized by several techniques, including XRD, N2 adsorption, SEM. The effects of ratios of Mg/Al catalyst, reaction temperature, catalyst dosage are thoroughly investigated to determine the optimal reaction conditions. A yield of biodiesel and glycerol carbonate could reach up to 87.5% and 93.4%, respectively, over Mg5Al-LDHs catalyst under batch condition. The transesterification glycerol for glycerol carbonate is successfully carried out in a stirring packed-bed reactor with MgxAl-LDHs coating on the spherical α-Al2O3 catalysts. Additionally, extra-particle mass transfer and intra-particle diffusion do not control the reaction rate. The yield of glycerol carbonate could reach up to 80.2% over Mg5Al-LDHs/α-Al2O3 catalyst.

Hydrogen production by oxidative reforming of ethanol in a fluidized bed reactor using a Pt Ni/CeO2SiO2 catalyst

Abstract Oxidative steam reforming of ethanol (OESR) was investigated over Pt Ni/CeO2 SiO2 catalysts prepared from different cerium salt precursors. During stability tests performed at 500 °C, steam/ethanol ratio (S/E) of 4 and oxygen/ethanol ratio of 0.5 (O/E), the highest performance was recorded over the catalyst prepared form organic precursors. The most promising formulation was tested at different temperatures, S/E and O/E. Complete conversion was recorded during 100 h of the test at 600 °C, with a very low carbon formation rate (6.9·10−7 gcoke, oxidized·gcatalyst−1·gcarbon,fed−1·h−1). The increase of oxygen content in the reacting mixture from 5 to 7.5% had a beneficial effect on H2 yield, which rose of more than 20% after 100 h of test, and on the conversion of by-products. When steam/ethanol ratio grew from 4 to 6, a slightly lower performance improvement was observed. Therefore, the highest activity and stability during OESR over the Pt Ni/CeO2 SiO2 catalyst prepared from organic salts was achieved at 600 °C, O/E = 0.75 and S/E = 6.

Experimental and Computational Demonstration of a Low-Temperature Waste to By-Product Conversion of U.S. Oil Shale Semi-Coke to a Flue Gas Sorbent

The volatility of crude oil prices incentivizes the use of domestic alternative fossil fuel sources such as oil shale. For ex situ oil shale retorting to be economically and environmentally viable, we must convert the copious amounts of semi-coke waste to an environmentally benign, useable by-product. Using acid and acid + base treatments, we increased the surface area of the semi-coke samples from 15 m2/g (pyrolyzed semi-coke) to upwards of 150 m2/g for hydrochloric acid washed semi-coke. This enhancement in porosity and surface area is accomplished without high temperature treatment, which lowers the overall energy required for such a conversion. XRD analysis confirms that chemical treatments removed the majority of dolomite while retaining other carbonate minerals and maintaining carbon contents of approximately 10%, which is greater than many fly ashes that are commonly used as sorbent materials. SO2 gas adsorption isotherm analysis determined that a double HCl treatment of semi-coke produces sorbents for flue gas treatment with higher SO2 capacities than commonly used fly ash adsorbents. Computational fluid dynamics modeling indicates that the sorbent material could be used in a fixed bed reactor to efficiently remove SO2 from the gas stream.

Sustainability assessment of symbiotic processes for the reuse of phosphogypsum

Abstract The conversion of by-products to resources is a novel approach for enhancing circular economy through increasing the lifecycle of resources, however, it does not always achieve sustainability outcomes. A life cycle assessment has been conducted to assess the economic and environmental implications of the conversion of phosphogypsum, which is a by-product from phosphoric acid manufacture, to useful resources such as paper and fertilizer. The current research found that the phosphogypsum based paper and fertilizer are neither environmentally nor economically better than conventional products due to the raw materials used that leads to higher environmental impact and economic cost. However, phosphogypsum based products offers some social benefits such as additional employment creation and enhanced intergenerational equity. Further investigation into chemical process design in terms of reagent selection for precipitation reactions is needed to achieve the economic and environmental feasibility of the products based on these by-products.

Simple route to synthesize (E)-3-propyl-4-oxo-2-butenoic acid esters through the Z isomer

ABSTRACTEsters of 3-alkyl-4-oxo-2-butenoic acid, which are very important synthons, are not equally accessible in both E and Z configurations. The (Z)-isomers can be easily obtained from 3-alkyl-4-hydroxybutenolides, in turn prepared by aminoalkylation of aliphatic aldehydes with glyoxylic acid. The (E)-isomers, on the contrary, result from laborious procedures: the condensation of aldehydes with glyoxylic acid, followed by separation from γ-hydroxybutenolide by-product and esterification, or of aldehyde enamines with glyoxylic esters, followed by Z ester by-product conversion into γ-aminobutenolide and purification. Here, we describe a straightforward route to the title compounds, applied to methyl (E)-3-propyl-4-oxo-2-butenoate, avoiding any problematic by-product or isomer chromatographic separation: pentanal and glyoxylic acid are condensed to 3-propyl-4-hydroxybutenolide, which is converted to methyl (Z)-3-propyl-4-oxo-2-butenoate and then isomerized to E ester under acidic conditions.

Patates İşleme Endüstrisi Yan Ürünleri ve Hayvan Beslemede Değerlendirilmesi

All around the world, particularly in developed countries, fresh potato consumption decreased while the consumption as fast food, snack and convenience food was increased. Potato processing industry has by-products such as cull potato, peel, pulp, and waste water. These by-products can be utilized for production of ethyl alcohol, single cell protein, microbial enzymes, lactic acid, organic fertilizer and bioethanol. The pulp obtained from the processing of potato for starch production can be considered as an energy source with starch content in animal nutrition. Recently, potato peel with the contents of bioactive compounds (chlorogenic, caffeic, gallic, protocatechuic acids) and their antioxidant and antimicrobial effects have been intensely focused on. Conversion of by-products of potato processing industry into value-added products is economically important. It was reviewed here by-products of potato processing industry and their evaluation in animal nutrition.

Optimization of the Production of Dietary Fiber Concentrates from By-Products of Papaya (Carica papayaL. Var. Formosa) with Microwave Assistance. Evaluation of Its Physicochemical and Functional Characteristics

A process involving an ethanol extraction step and microwave assisted dehydration was designed to produce dietary fiber concentrates (DFC) from papaya (Carica papaya L. var. Formosa) by-products. It was concluded that a 15 min extraction with 2.9 mL of ethanol/g of papaya pulp followed by drying performed at 40C, produced DFC with optimal values for functional properties (hydration properties, oil holding capacity, specific volume, water soluble fraction) as well as b* color parameter and content of phenolic compounds. The DFC obtained from papaya peel using the same conditions, showed a higher content of cell wall polysaccharides and higher glass transition temperature (38C) than the one obtained from pulp (8C) and the polyphenol content doubled the one of pulp. Both DFCs showed potential to be used for nutritional purposes as well as for technological applications as antioxidants and/or thickeners. Practical Applications Consumer demands for more healthy food products and global policies on the issues of health and environment are the keys for the development of innovative food products with profitable markets. The conversion of by-products from the papaya industrialization to dietary fiber concentrates (DFC) with functional activity fulfills these requirements, being salad dressings or dairy products, the targets for DFC application as viscosity modifiers and nutritional value improvers.

Overexpression of the genes PDC1 and ADH1 activates glycerol conversion to ethanol in the thermotolerant yeast Ogataea (Hansenula) polymorpha.

Conversion of byproduct from biodiesel production glycerol to high-value compounds is of great importance. Ethanol is considered a promising product of glycerol bioconversion. The methylotrophic thermotolerant yeast Ogataea (Hansenula) polymorpha is of great interest for this purpose as the glycerol byproduct contains methanol and heavy metals as contaminants, and this yeast utilizes methanol and is relatively resistant to heavy metals. Besides, O. polymorpha shows robust growth on glycerol and produces ethanol from various carbon sources. The thermotolerance of this yeast is an additional advantage, allowing increased fermentation temperature to 45-48 °C, leading to increased rate of the fermentation process and a fall in the cost of distillation. The wild-type strain of O. polymorpha produces insignificant amounts of ethanol from glycerol (0.8 g/l). Overexpression of PDC1 coding for pyruvate decarboxylase enhanced ethanol production up to 3.1 g/l, whereas simultaneous overexpression of PDC1 and ADH1 (coding for alcohol dehydrogenase) led to further increase in ethanol production from glycerol. Moreover, the increased temperature of fermentation up to 45 °C stimulated the production of ethanol from glycerol used as the only carbon source up to 5.0 g/l, which exceeds the data obtained by methylotrophic yeast strains reported so far. Copyright © 2016 John Wiley & Sons, Ltd.

Catalytically Active Cermet Membrane for Converting Byproducts from the Production of Combustibles

The conversion of waste byproducts in water, which are formed stoichiometrically as result of the Fischer–Tropsch process, in obtaining combustibles is examined. Theoretical and experimental studies of the vacuum synthesis of cermet membranes based on the system Al–Ni–Co3O4 are performed. The membranes obtained give 85 – 99% conversion of byproducts into syngas.

Conversion of by-products from the vegetable oil industry into biodiesel and its use in internal combustion engines: a review

Biodiesel produced from by-products and waste materials can be an economical way of reducing traditional oil consumption and environmental problems. The by-products from the vegetable oil refining industry such as soapstock, acid oil and fatty acid distillates are suitable for producing biodiesel. The present work is a survey related to the use of these by-products to obtain biodiesel, covering not only the traditional and most widely used acid/base catalysis, but also solid and enzymatic catalysis. Details of the techniques are presented and compared. The advantages and drawbacks of the different approaches are mentioned and analyzed. The synthesis and use of by-products from the vegetable oil refining industry are covered in this work. The use of the obtained biodiesel in diesel engines is also included, demonstrating the disparity between the number of papers related to biodiesel production and engine performance assessment.

Heavy Metals in Colorado and Chinese Oil Shale Semicoke: Disposal Issues, Impediments to Byproduct Conversion

Oil shale, a fine-grained sedimentary rock, contains a proportionally large amount of kerogen, which can be converted into oil by thermal degradation of the compacted rock. The primary byproduct of current oil shale oil extraction processes is semicoke. Its landfill deposition presents a possible threat to the environment and represents a waste of a potentially useable byproduct. In this work, we explore the heavy metal content of oil shale semicoke pyrolyzed at 500 and 1000 °C to better understand the risks posed by disposal of oil shale processing waste on the nearby environment, as well as impediments to potential byproduct conversion. The greatest potential obstruction to byproduct conversion and the greatest environmental risk posed by open air disposal of oil shale semicoke is likely due to relatively high arsenic concentrations; using X-ray fluorescence spectroscopy, we find arsenic concentrations in semicoke (pyrolyzed at 500 °C) ranging from 25 ppm for Chinese oil shale from the Huadian mine (class C) to 79 ppm for Green River, Colorado, 50 gallons per ton (GPT) of oil shale. Other heavy metal elements analyzed, including barium, copper, lead, manganese, and iron, are well below the United States Environmental Protection Agency (U.S. EPA) regional screening limits.

Removal of some heavy metals ions from wastewater by copolymer of iron and aluminum impregnated with active silica derived from rice husk ash

Recently because of increasing of the environmental awareness and demands, several attempts were carried out for the conversion of by-products of natural materials, especially agricultural wastes, to highly sorption capacity materials. In recent years, attention has been focused on the utilization of unmodified or modified agro-residues as sorbents for removal of pollutants. Various modifications have been reported to enhance sorption capacities for heavy metals. The present study deals with the adsorption equilibrium of iron, manganese, lead and arsenic ions from aqueous solutions on copolymer of Al +3, Si +4 and Fe +3 using batch techniques. The influence of various parameters, such as agitation time, sorbent mass and pH of sorbate solution were investigated. Under this study the maximum adsorption capacity of iron and aluminum copolymer impregnated with silica (PAlFeClSi) for lead, iron, manganese and arsenic are found to be 416, 222, 158, 146 mg/g, respectively.