Parameter identification of the fermentative production of fructo-oligosaccharides by Aureobasidium pullulans

In this study, a mathematical model for the production of Fructo-oligosaccharides (FOS) by Aureobasidium pullulans is developed. This model contains a relatively large set of unknown parameters, and the identification problem is analyzed using simulation data, as well as experimental data. Batch experiments were not sufficiently informative to uniquely estimate all the unknown parameters, thus, additional experiments have to be achieved in fed-batch mode to supplement the missing information. © 2015 IEEE.

Entwicklung und Optimierung eines Verfahrens zur Viruspropagation von Parapoxvirus Ovis NZ-2

Parapoxvirus-ovis, Bovine Kidney Cell Line, Fed-Batch, Dialysis, Volume-Expanded-Fed Batch, Scale-Up, Shear-Force, Membrane Aeration

Isentropic Exergy and Pressure of the Shock Wave Caused by the Explosion of a Pressure Vessel

An accidental burst of a pressure vessel is an uncontrollable and explosion-like batch process. In this study it is called an explosion. The destructive effectof a pressure vessel explosion is relative to the amount of energy released in it. However, in the field of pressure vessel safety, a mutual understanding concerning the definition of explosion energy has not yet been achieved. In this study the definition of isentropic exergy is presented. Isentropic exergy is the greatest possible destructive energy which can be obtained from a pressure vessel explosion when its state changes in an isentropic way from the initial to the final state. Finally, after the change process, the gas has similar pressure and flow velocity as the environment. Isentropic exergy differs from common exergy inthat the process is assumed to be isentropic and the final gas temperature usually differs from the ambient temperature. The explosion process is so fast that there is no time for the significant heat exchange needed for the common exergy.Therefore an explosion is better characterized by isentropic exergy. Isentropicexergy is a characteristic of a pressure vessel and it is simple to calculate. Isentropic exergy can be defined also for any thermodynamic system, such as the shock wave system developing around an exploding pressure vessel. At the beginning of the explosion process the shock wave system has the same isentropic exergyas the pressure vessel. When the system expands to the environment, its isentropic exergy decreases because of the increase of entropy in the shock wave. The shock wave system contains the pressure vessel gas and a growing amount of ambient gas. The destructive effect of the shock wave on the ambient structures decreases when its distance from the starting point increases. This arises firstly from the fact that the shock wave system is distributed to a larger space. Secondly, the increase of entropy in the shock waves reduces the amount of isentropic exergy. Equations concerning the change of isentropic exergy in shock waves are derived. By means of isentropic exergy and the known flow theories, equations illustrating the pressure of the shock wave as a function of distance are derived. Amethod is proposed as an application of the equations. The method is applicablefor all shapes of pressure vessels in general use, such as spheres, cylinders and tubes. The results of this method are compared to measurements made by various researchers and to accident reports on pressure vessel explosions. The test measurements are found to be analogous with the proposed method and the findings in the accident reports are not controversial to it.

Suolan pesu ja liuottimen strippaus selluloosaeetteristä

Työssä tutkittiin suolan pesua ja liuottimen strippausta selluloosaeetteristä. Työn tavoitteena oli tutkia erään selluloosaeetterin ominaisuuksien vaikutusta pesuun ja strippaukseen. Strippauksesta selvitettiin pääasiallisesti alipaineen ja lämpötilan vaikutusta tarvittavaan höyrymäärään. Työn kirjallisuusosassa tarkasteltiin selluloosaeetterin valmistuksen teoriaa, pesu- ja strippausprosesseihin vaikuttavia muuttujia sekä erilaisia pesu- ja strippausprosesseihin soveltuvia laitteita. Kokeet suoritettiin pilotlaitoksellaja kahdella tuotantolinjalla. Pilotlaitos oli panosprosessi ja tuotantolinjat olivat jatkuvatoimisia prosesseja. Kokeiden analyysitulokset käsiteltiin lineaarisella regressioanalyysillä. Analyysitulosten perusteella todettiin strippausalipaineen kasvun ja -lämpötilan noston lisäävän tarvittavaa höyrymäärää strippauksessa. Myös stripattavan selluloosaeetterin kosteuspitoisuuden kasvun havaittiin lisäävän tarvittavaa höyrymäärää strippauksessa.

Removal of Pb(II) ions and malachite green dye from wastewater by activated carbon produced from lemon peel

In the present study, a high-surface area activated carbon was prepared by chemical activation of lemon peel with H3PO4 as the active agent. Then, the adsorption behavior of Malachite green dye and Pb(II) ions on the produced activated carbon was studied. Batch process was employed for sorption kinetics and equilibrium studies. Experimental data were fitted to various isotherm models. According to the Langmuir model, the maximum adsorption capacities of Malachite green dye and Pb(II) ions were found to be 66.67 and 90.91 mg g-1, respectively, at room temperature. Kinetic studies showed the adsorption process followed a pseudo second-order rate model. The sorption kinetics were controlled by intra-particle diffusion. The results indicated that the produced activated carbon can be economically and effectively used as an adsorbent for the removal of Malachite green dye and Pb(II) ions from wastewaters.

Influence of plasma modification on surface properties and offset printability of coated paper

The properties of the paper surface play a crucial role in ensuring suitable quality and runnability in various converting and finishing operations, such as printing. Plasma surface modification makes it possible to modify the surface chemistry of paper without altering the bulk material properties. This also makes it possible to investigate the role of the surface chemistry alone on printability without influencing the porous structure of the pigment-coated paper. Since the porous structure of a pigment coating controls both ink setting and optical properties, surface chemical changes created by a plasma modification have a potential to decouple these two effects and to permit a better optimization of them both. The aim of this work was to understand the effects of plasma surface modification on paper properties, and how it influences printability in the sheet-fed offset process. The objective was to broaden the fundamental understanding of the role of surface chemistry on offset printing. The effects of changing the hydrophilicity/ hydrophobicity and the surface chemical composition by plasma activation and plasma coatings on the properties of coated paper and on ink-paper interactions as well as on sheet-fed offset print quality were investigated. In addition, the durability of the plasma surface modification was studied. Nowadays, a typical sheet-fed offset press also contains units for surface finishing, for example UVvarnishing. The role of the surface chemistry on the UV-varnish absorption into highly permeable and porous pigment-coated paper was also investigated. With plasma activation it was possible to increase the surface energy and hydrophilicity of paper. Both polar and dispersion interactions were found to increase, although the change was greater in the polar interactions due to induced oxygen molecular groups. The results indicated that plasma activation takes place particularly in high molecular weight components such as the dispersion chemicals used to stabilize the pigment and latex particles. Surface composition, such as pigment and binder type, was found to influence the response to the plasma activation. The general trend was that pilot-scale treatment modified the surface chemistry without altering the physical coating structure, whereas excessive laboratory-scale treatment increased the surface roughness and reduced the surface strength, which led to micro-picking in printing. It was shown that pilot-scale plasma activation in combination with appropriate ink oils makes it possible to adjust the ink-setting rate. The ink-setting rate decreased with linseed-oil-based inks, probably due to increased acid-base interactions between the polar groups in the oil and the plasma-treated paper surface. With mineral-oil-based inks, the ink setting accelerated due to plasma activation. Hydrophobic plasma coatings were able to reduce or even prevent the absorption of dampening water into pigmentcoated paper, even when the dampening water was applied under the influence of nip pressure. A uniform hydrophobic plasma coating with sufficient chemical affinity with ink gave an improved print quality in terms of higher print density and lower print mottle. It was also shown that a fluorocarbon plasma coating reduced the free wetting of the UV-varnish into the highly permeable and porous pigment coating. However, when the UV-varnish was applied under the influence of nip pressure, which leads to forced wetting, the role of the surface chemical composition seems to be much less. A decay in surface energy and wettability occurred during the first weeks of storage after plasma activation, after which it leveled off. However, the oxygen/carbon elemental ratio did not decrease as a function of time, indicating that ageing could be caused by a re-orientation of polar groups or by a contamination of the surface. The plasma coatings appeared to be more stable when the hydrophobicity was higher, probably due to fewer interactions with oxygen and water vapor in the air.

Synthesis of percarboxylic acids in microreactor

Percarboxylic acids are commonly used as disinfection and bleaching agents in textile, paper, and fine chemical industries. All of these applications are based on the oxidative potential of these compounds. In spite of high interest in these chemicals, they are unstable and explosive chemicals, which increase the risk of synthesis processes and transportation. Therefore, the safety criteria in the production process should be considered. Microreactors represent a technology that efficiently utilizes safety advantages resulting from small scale. Therefore, microreactor technology was used in the synthesis of peracetic acid and performic acid. These percarboxylic acids were produced at different temperatures, residence times and catalyst i.e. sulfuric acid concentrations. Both synthesis reactions seemed to be rather fast because with performic acid equilibrium was reached in 4 min at 313 K and with peracetic acid in 10 min at 343 K. In addition, the experimental results were used to study the kinetics of the formation of performic acid and peracetic acid. The advantages of the microreactors in this study were the efficient temperature control even in very exothermic reaction and good mixing due to the short diffusion distances. Therefore, reaction rates were determined with high accuracy. Three different models were considered in order to estimate the kinetic parameters such as reaction rate constants and activation energies. From these three models, the laminar flow model with radial velocity distribution gave most precise parameters. However, sulfuric acid creates many drawbacks in this synthesis process. Therefore, a ´´greener´´ way to use heterogeneous catalyst in the synthesis of performic acid in microreactor was studied. The cation exchange resin, Dowex 50 Wx8, presented very high activity and a long life time in this reaction. In the presence of this catalyst, the equilibrium was reached in 120 second at 313 K which indicates a rather fast reaction. In addition, the safety advantages of microreactors were investigated in this study. Four different conventional methods were used. Production of peracetic acid was used as a test case, and the safety of one conventional batch process was compared with an on-site continuous microprocess. It was found that the conventional methods for the analysis of process safety might not be reliable and adequate for radically novel technology, such as microreactors. This is understandable because the conventional methods are partly based on experience, which is very limited in connection with totally novel technology. Therefore, one checklist-based method was developed to study the safety of intensified and novel processes at the early stage of process development. The checklist was formulated using the concept of layers of protection for a chemical process. The traditional and three intensified processes of hydrogen peroxide synthesis were selected as test cases. With these real cases, it was shown that several positive and negative effects on safety can be detected in process intensification. The general claim that safety is always improved by process intensification was questioned.

Cellulase effect on anaerobic digestion of maize silage under discontinuous operation

ABSTRACT This paper studied the effect of adding an enzyme (ellulose) on anaerobic digestion of maize silage. We compared materials at chopping lengths of 8 mm (MSL), 4mm (MSS) and natural size (Ms) under a mesophilic and discontinuous operation (batch process). Hence, we found the process to be significantly influenced by particle size. Moreover, the ellulose addition did not significantly impact biogas production after a 35-day digestion period. Ms and MSS displayed an improved response to all variables when compared with MSL and MSL+C, with significant differences. Studies on the refractory fraction at infinite time (R0) have demonstrated that the lowest values correspond to Ms and MSS (0.122 and 0.155, respectively). The Kinetic approach and the Ultimate Biodegradability test are useful tools to evaluate the effect of the addition of an enzyme to the anaerobic process.

Käytetyn voiteluöljyn regenerointilaitoksen prosessivesien karakterisointi

Käytetyn voiteluöljyn regeneroinnissa muodostuu prosessivettä useista lähteistä. Tehokas päästöjenhallinta on yksi tärkeimmistä tavoitteista regenerointilaitoksen operoinnissa ja sen takia sitä tulee kehittää jatkuvasti entistä paremmaksi. Tavoitteisiin pääsemiseksi on oleellista tunnistaa vesienkäsittelyprosessin laadullinen massatase ja laadunvaihtelut ajotilanteiden mukaan. Työssä tutkitaan ja analysoidaan veden sisältämiä epäpuhtauksia sekä kirjallisuuslähteiden perusteella, että standardimenetelmillä ja modifioiduilla menetelmillä, joilla on akkreditointi. Analyysituloksista muodostetaan laadullinen massatase, josta nähdään epäpuhtauksien ja niitä kuvaavien parametrien kuormitukset kussakin prosessivesivirrassa. Tulosten perusteella arvioidaan nykyisen vesienkäsittelyn tehokkuutta, sen säätömahdollisuuksia ja kehitystarvetta. Tarkastelun ulkopuolelle kuitenkin jätetään vesienkäsittelystä ulosjohdettavan prosessiveden puhdistuslaitos. Tutkimusten perusteella regenerointilaitoksessa muodostuvien prosessivesien epäpuhtaudet koostuvat öljystä, BTEX-yhdisteistä, fenoliyhdisteistä, liuottimista, polttoaineiden ja voiteluöljyjen lisäaineista, typpi- ja rikkiyhdisteistä, metalliyhdisteistä sekä kiintoaineesta. Öljy jakautuu kevyisiin (C5-C10), keskiraskaisiin (C10-21) ja raskaisiin (C21-40) jakeisiin. Vesienkäsittelyssä suurin osa öljystä ja epäpuhtauksista saadaan erottumaan vedestä, jolloin puhdistuslaitokselle päätyy jäämäpitoisuudet öljyä, haihtuvia yhdisteitä sekä muita epäpuhtauksia. Puhdistuslaitosta kuormittavat eniten liuenneet orgaaniset yhdisteet sekä korkeaa kemiallista hapenkulutusta aiheuttavat epäorgaaniset yhdisteet (suolat), joiden erottamista prosessivesistä on syytä tulevaisuudessa kehittää.

Lignoselluloosapohjaisten väkevähappohydrolysaattien jatkuvatoiminen kromatografinen fraktiointi

Työssä tutkittiin lignoselluloosapohjaisten väkevähappohydrolysaattien (monosakkaridit, rikki- ja etikkahppo) jatkuvatoimista kromatografista fraktiointia käyttäen Japan Organo SMB -prosessia. Adsorbenttinä toimi happomuotoinen (H+) vahva kationinvaihtohartsi. Panostoimista fraktiointia käytettiin vertailukohtana. Jatkuvatoimisen prosessin optimoinnilla saavutettiin monosakkaridien suurimmaksi tuottavuudeksi 283 mol/(m3 h) (panosprosessille 145 mol/(m3 h). JO-prosessilla saavutettiin korkeat rikki- ja etikkahapon saannot: 97,3 % ja 93,5 %. Monosakkaridisaanto jäi hieman alhaisemmaksi (61,7 %) johtuen monosakkaridi- ja rikkihappo-profiilien hankalasta erottamisesta. Ulostulo virtojen puhtaudet olivat korkeat: 89 % monosakkarideille, 89 % rikkihapolle ja 100 % etikkahapolle.

Chromatographic recovery of chemicals from acidic biomass hydrolysates

Lignocellulosic biomasses (e.g., wood and straws) are a potential renewable source for the production of a wide variety of chemicals that could be used to replace those currently produced by petrochemical industry. This would lead to lower greenhouse gas emissions and waste amounts, and to economical savings. There are many possible pathways available for the manufacturing of chemicals from lignocellulosic biomasses. One option is to hydrolyze the cellulose and hemicelluloses of these biomasses into monosaccharides using concentrated sulfuric acid as catalyst. This process is an efficient method for producing monosaccharides which are valuable platforn chemicals. Also other valuable products are formed in the hydrolysis. Unfortunately, the concentrated acid hydrolysis has been deemed unfeasible mainly due to high chemical consumption resulting from the need to remove sulfuric acid from the obtained hydrolysates prior to the downstream processing of the monosaccharides. Traditionally, this has been done by neutralization with lime. This, however, results in high chemical consumption. In addition, the by-products formed in the hydrolysis are not removed and may, thus, hinder the monosaccharide processing. In order to improve the feasibility of the concentrated acid hydrolysis, the chemical consumption should be decreased by recycling of sulfuric acid without neutralization. Furthermore, the monosaccharides and the other products formed in the hydrolysis should be recovered selectively for efficient downstream processing. The selective recovery of the hydrolysis by-products would have additional economical benefits on the process due to their high value. In this work, the use of chromatographic fractionation for the recycling of sulfuric acid and the selective recovery of the main components from the hydrolysates formed in the concentrated acid hydrolysis was investigated. Chromatographic fractionation based on the electrolyte exclusion with gel type strong acid cation exchange resins in acid (H+) form as a stationary phase was studied. A systematic experimental and model-based study regarding the separation task at hand was conducted. The phenomena affecting the separation were determined and their effects elucidated. Mathematical models that take accurately into account these phenomena were derived and used in the simulation of the fractionation process. The main components of the concentrated acid hydrolysates (sulfuric acid, monosaccharides, and acetic acid) were included into this model. Performance of the fractionation process was investigated experimentally and by simulations. Use of different process options was also studied. Sulfuric acid was found to have a significant co-operative effect on the sorption of the other components. This brings about interesting and beneficial effects in the column operations. It is especially beneficial for the separation of sulfuric acid and the monosaccharides. Two different approaches for the modelling of the sorption equilibria were investigated in this work: a simple empirical approach and a thermodynamically consistent approach (the Adsorbed Solution theory). Accurate modelling of the phenomena observed in this work was found to be possible using the simple empirical models. The use of the Adsorbed Solution theory is complicated by the nature of the theory and the complexity of the studied system. In addition to the sorption models, a dynamic column model that takes into account the volume changes of the gel type resins as changing resin bed porosity was also derived. Using the chromatography, all the main components of the hydrolysates can be recovered selectively, and the sulfuric acid consumption of the hydrolysis process can be lowered considerably. Investigation of the performance of the chromatographic fractionation showed that the highest separation efficiency in this separation task is obtained with a gel type resin with a high crosslinking degree (8 wt. %); especially when the hydrolysates contain high amounts of acetic acid. In addition, the concentrated acid hydrolysis should be done with as low sulfuric acid concentration as possible to obtain good separation performance. The column loading and flow rate also have large effects on the performance. In this work, it was demonstrated that when recycling of the fractions obtained in the chromatographic fractionation are recycled to preceding unit operations these unit operations should included in the performance evaluation of the fractionation. When this was done, the separation performance and the feasibility of the concentrated acid hydrolysis process were found to improve considerably. Use of multi-column chromatographic fractionation processes, the Japan Organo process and the Multi-Column Recycling Chromatography process, was also investigated. In the studied case, neither of these processes could compete with the single-column batch process in the productivity. However, due to internal recycling steps, the Multi-Column Recycling Chromatography was found to be superior to the batch process when the product yield and the eluent consumption were taken into account.

Purification of Hydrocarbon Waste Streams

Purification of hydrocarbon waste streams is needed to recycle valuable hydrocarbon products, reduce hazardous impacts on environment, and save energy. To obtain these goals, research must be focused on the search of effective and feasible purification and re-refining technologies. Hydrocarbon waste streams can contain both deliberately added additives to original product and during operation cycle accumulated undesired contaminants. Compounds may have degenerated or cross-reacted. Thus, the presence of unknown species cause additional challenges for the purification process. Adsorption process is most suitable to reduce impurities to very low concentrations. Main advantages are availability of selective commercial adsorbents and the regeneration option to recycle used separation material. Used hydrocarbon fraction was purified with various separation materials in the experimental part. First screening of suitable materials was done. In the second stage, temperature dependence and adsorption kinetics were studied. Finally, one fixed bed experiment was done with the most suitable material. Additionally, FTIR-measurements of hydrocarbon samples were carried out to develop a model to monitor the concentrations of three target impurities based on spectral data. Adsorption capacities of the tested separation materials were observed to be low to achieve high enough removal efficiencies for target impurities. Based on the obtained data, batch process would be more suitable than a fixed bed process and operation at high temperatures is favorable. Additional pretreatment step is recommended to improve removal efficiency. The FTIR-measurement was proven to be a reliable and fast analysis method for challenging hydrocarbon samples.

Cassava wastewater (manipueira) treatment using a two-phase anaerobic biodigestor

A two-phase anaerobic biodigestor was employed in order to analyze methane production with different manipueira organic loading rates. The acidogenic phase was carried out in a batch process whereas the methanogenic in an up-flow anaerobic fixed bed reactor with continuous feeding. The organic loading rates varied from 0.33 up to 8.48g of Chemical Demand Oxygen (COD)/L.day. The highest content of methane, 80.9%, was obtained with organic loading rate of 0.33g and the lowest, 56.8%, with 8.48gCOD/L.d. The highest reduction of COD, 88.89%, was obtained with organic loading rate of 2.25g and the lowest, 54.95%, with 8.48gCOD/L.d. From these data it was possible to realize that anaerobic biodigestion can be managed in at least two ways, i.e., for energy production (methane) or for organic loading reduction. The organic loading rate should be calculated as part of the purpose of the treatment to be accomplished.

Enzymatic Synthesis, Recovery, and Purification of Ethyl β-ᴅ-glucopyranoside

A method to synthesize ethyl β-ᴅ-glucopyranoside (BEG) was searched. Feasibility of different ion exchange resins was examined to purify the product from the synthetic binary solution of BEG and glucose. The target was to produce at least 50 grams of 99 % pure BEG with a scaled up process. Another target was to transfer the batch process into steady-state recycle chromatography process (SSR). BEG was synthesized enzymatically with reverse hydrolysis utilizing β-glucosidase as a catalyst. 65 % of glucose reacted with ethanol into BEG during the synthesis. Different ion exchanger based resins were examined to separate BEG from glucose. Based on batch chromatography experiments the best adsorbent was chosen between styrene based strong acid cation exchange resins (SAC) and acryl based weak acid cation exchange resins (WAC). CA10GC WAC resin in Na+ form was chosen for the further separation studies. To produce greater amounts of the product the batch process was scaled up. The adsorption isotherms for the components were linear. The target purity was possible to reach already in batch without recycle with flowrate and injection size small enough. 99 % pure product was produced with scaled-up batch process. Batch process was transferred to SSR process utilizing the data from design pulse chromatograms and Matlab simulations. The optimal operating conditions for the system were determined. Batch and SSR separation results were compared and by using SSR 98 % pure products were gained with 40 % higher productivity and 40 % lower eluent consumption compared to batch process producing as pure products.

Continuous production of L-glutaminase by an immobilized marine Pseudomonas sp BTMS-51 in a packed bed reactor

A marine Pseudomonas sp BTMS-51, immobilized by Ca-alginate gel entrapment was used for the production of extracellular Lglutaminase under repeated batch process and continuous process employing a packed bed reactor (PBR). Immobilized cells could produce an average of 25 U/ml of enzyme over 20 cycles of repeated batch operation and did not show any decline in production upon reuse. The enzyme yield correlated well with the biomass content in the beads. Continuous production of the enzyme in PBR was studied at different substrate concentrations and dilution rates. In general, the volumetric productivity increased with increased dilution rate and substrate concentrations and the substrate conversion efficiency declined. The PBR operated under conditions giving maximal substrate conversion efficiency gave an average yield of 21.07 U/ml and an average productivity of 13.49 U/ml/h. The system could be operated for 120 h without any decline in productivity