Seedling establishment after prescribed burning of a Clear-Cut and Partially Cut mesic boreal forest in Southern Finland

Summary

Fischer-Tropsch Slurry Bubble Column Reactor Modeling

The literature part of the work reviews overall Fischer-Tropsch process, Fischer-Tropsch reactors and catalysts. Fundamentals of Fischer-Tropsch modeling are also presented. The emphasis is on the reactor unit. Comparison of the reactors and the catalysts is carried out to choose the suitable reactor setup for the modeling work. The effects of the operation conditions are also investigated. Slurry bubble column reactor model operating with cobalt catalyst is developed by taking into account the mass transfer of the reacting components (CO and H2) and the consumption of the reactants in the liquid phase. The effect of hydrostatic pressure and the change in total mole flow rate in gas phase are taken into account in calculation of the solubilities. The hydrodynamics, reaction kinetics and product composition are determined according to literature. The cooling system and furthermore the required heat transfer area and number of cooling tubes are also determined. The model is implemented in Matlab software. Commercial scale reactor setup is modeled and the behavior of the model is investigated. The possible inaccuraries are evaluated and the suggestions for the future work are presented. The model is also integrated to Aspen Plus process simulation software, which enables the usage of the model in more extensive Fischer-Tropsch process simulations. Commercial scale reactor of diameter of 7 m and height of 30 m was modeled. The capacity of the reactor was calculated to be about 9 800 barrels/day with CO conversion of 75 %. The behavior of the model was realistic and results were in the right range. The highest uncertainty to model was estimated to be caused by the determination of the kinetic rate.

Kromatografinen erotus bioetanolin valmistuksessa lignoselluloosasta

Bioetanolin tuotanto kiinnostaa monissa maissa johtuen kansainvälisissä sopimuksissa määritellyistä ilmastotavoitteista. Työssä tutkittiin laboratorio-oloissa ioninvaihtohartsien ominaisuuksien ja erotuksen olosuhteiden vaikutusta rikkihapon ja glukoosin kromatografiseen erotukseen. Tehokkaimmaksi hartsiksi osoittautui polysulfonoitu mesohuokoinen vahva kationinvaihtohartsi Finex CS100C. CS100C:lla voitiin erottaa rikkihappoa ja glukoosia tehokkaimmin korkeissa 25 p-% ja 36 p-% glukoosi- ja rikkihappo-pitoisuuksissa. Lisäksi sillä havaittiin suurin tuotto simuloidussa liikkuvassa pedissä. Yhdessä kolonnissa suoritetuissa erotuskokeissa tutkittiin hartsien erotuskykyä rikkihapolle ja glukoosille sekä virtausnopeuden vaikutusta erotukseen lämpötilassa 22 °C. Saatujen tulosten pohjalta valittiin CS11GC, CS16GC ja CS100C tarkempaan isotermin määritykseen ja simulointiin hyvän erotuskyvyn sekä keskinäisten erojen takia. Adsorptioisotermit määritettiin kolonnikokein sekä 22 °C:n että 50 °C:n lämpötilassa. Isotermeistä havaittiin, että tasapaino kiinto- ja liuosfaasien välille saavutetaan rikkihapolla alhaisella 1 cm3/min virtausnopeudella varmemmin kuin suuremmalla 2,5 cm3/min virtausnopeudella. 50 °C:n lämpötilassa hapon ja glukoosin isotermit olivat jyrkempiä kuin 22 °C:n lämpötilassa. Määritettyihin hapon ja sokerin isotermeihin sovitettiin mallit, joiden parametreja käytettiin yksittäisen kolonnin simulointiin. Simuloinnissa oli estimoitavia parametreja yhdellä kolonnilla aineensiirtokertoimet sekä läpäisykäyristä määritetyt isotermiparametrit glukoosille sekä rikkihapolle ja SMB–erotuksessa vyöhykkeiden 2 ja 3 suhteelliset virtausnopeudet. Siirryttäessä lämpötilojen 22 °C ja 50 °C välillä hartsien parametrit muuttuivat sokerille täysin ja hapolle vain aineensiirtokertoimen osalta. CS100C oli tehokkain SMB–erotuksessa korkeimmalla 0,11 cm3/min tuottavuudella 95 %:n saannon saavuttamiseksi 95 % tuotepuhtaudella raffinaatissa ja ekstraktissa.

Design and manufacture of a microdistillation column

Aim of this thesis was to design and manufacture a microdistillation column. The literature review part of this thesis covers stainless steels, material processing and basics about engineering design and distillation. The main focus, however, is on the experimental part. Experimental part is divided into five distinct sections: First part is where the device is introduced and separated into three parts. Secondly the device is designed part by part. It consists mostly of detail problem solving, since the first drawings had already been drawn and the critical dimensions decided. Third part is the manufacture, which was not fully completed since the final assembly was left out of this thesis. Fourth part is the test welding for the device, and its analysis. Finally some ideas for further studies are presented. The main goal of this thesis was accomplished. The device only lacks some final assembly but otherwise it is complete. One thing that became clear during the process was how difficult it is to produce small and precise steel parts with conventional manufacturing methods. Internal stresses within steel plates and thermal distortions can easily ruin small steel structures. Designing appropriate welding jigs is an important task for even simple devices. Laser material processing is a promising tool for this kind of steel processing because of the flexibility, good cutting quality and also precise and low heat input when welding. Next step in this project is the final assembly and the actual distillation tests. The tests will be carried out at Helsinki University of Technology.

Treatment of Fe-containing Acid Mine Waters in Fixed Bed Adsorption Column with Calcite Side-Stone

The acid mining drainage is considered the most significant environmental pollution problem around the world for the extensive formation acidic leachates containing heavy metals. Adsorption is widely used methods in water treatment due to it easy operation and the availability of a wide variety of commercial adsorbent (low cost). The primary goal of this thesis was to investigate the efficiency of neutralizing agents, CaCO3 and CaSiO3, and metal adsorption materials with unmodified limestone from Company Nordkalk Oy. In addition to this, the side materials of limestone mining were tested for iron adsorption from acidic model solution. This study was executed at Lappeenranta University of Technology, Finland. The work utilised fixed-bed adsorption column as the main equipment and large fluidized column. Atomic absorption spectroscopy (AAS) and x-ray diffraction (XRD) was used to determine ferric removal and the composition of material respectively. The results suggest a high potential for the studied materials to be used a low cost adsorbents in acid mine drainage treatment. From the two studied adsorbents, the FS material was more suitable than the Gotland material. Based on the findings, it is recommended that further studies might include detailed analysis of Gotland materials.

Value-based selling of the column connection solution as part of project sales

The objective of this study was to find out how third party influencers can facilitate value-based selling in a network and how suppliers should aim to impact on these third party influencers to facilitate value-based selling. The study considers construction industry, selling the column connection solution and third party influencers. Third party influencers examined in this study were structural designers. The study also aims to find out structural designers’ value drivers and the differences between the market areas that this study related to. The theoretical part of the study focuses on two separate areas. The first part of the theory focuses on a value-based selling concept: what it is, what it requires and what are the main barriers for value-based selling. The second part of the theory examines value creation in networks. The present knowledge over value creation in networks and different network actors are presented. Project marketing is also discussed briefly because this study’s topic, which is highly related to project business. The results reveal structural designers’ value drivers considering the usage of the column connection solution and present ways how suppliers should aim to impact structural designers to facilitate value-based selling. The main result of the study indicates that third party influencers can have a positive impact on facilitating value-based selling. Structural designers are communicating more or less with all the salient actors in different project phases and they can act as sponsors to support the sales of Peikko’s column connection solution and promote solution to other actors involved to the project. This requires that structural designers can understand the actual benefits of how the solution can improve their and their customers’ business.