Comparison of Biomass Gasification Technologies for Natural Gas Substitution in Iron Ore Pelletizing Plants

The iron ore pelletizing process consumes high amounts of energy, including nonrenewable sources, such as natural gas. Due to fossil fuels scarcity and increasing concerns regarding sustainability and global warming, at least partial substitution by renewable energy seems inevitable. Gasification projects are being successfully developed in Northern Europe, and large-scale circulating fluidized bed biomass gasifiers have been commissioned in e.g. Finland. As Brazil has abundant biomass resources, biomass gasification is a promising technology in the near future. Biomasses can be converted into product gas through gasification. This work compares different technologies, e.g. air, oxygen and steam gasification, focusing on the use of the product gas in the indurating machine. The use of biosynthetic natural gas is also evaluated. Main parameters utilized to assess the suitability of product gas were adiabatic flame temperature and volumetric flow rate. It was found that low energy content product gas could be utilized in the traveling grate, but it would require burner’s to be changed. On the other hand, bio-SGN could be utilized without any adaptions. Economical assessment showed that all gasification plants are feasible for sizes greater than 60 MW. Bio-SNG production is still more expensive than natural gas in any case.

Pellets prepared with mechanically activated iron ore

This work analyses pellets prepared with iron ore that has been mechanically activated by high energy ball milling. Pellet feed iron ore was submitted to high-energy ball milling for 60 minutes, and the resulting material was analysed through measurements of particle size and specific surface area, as well as X-ray diffraction. Pellets were prepared from this material. The pellets were heated at temperatures ranging from 1000 to 1250 degrees C in a muffle furnace, and submitted to the maximum temperature during 10 - 12 minutes. The samples were then tested regarding crushing strength, densification and porosity, and were examined in a scanning electronic microscope. The results were compared to those obtained with similar samples made from non-milled pellet feed. It has been shown that through high-energy ball milling of iron ore it is possible to achieve pellets presenting high densification and compressive strength at firing temperatures lower than the usual ones.

Puupellettien tuotanto-, jakelu- ja käyttöketjun tekniikka, talous ja markkinat

Puupelletti on puumurskeesta puristamalla valmistettu polttoainejaloste, jonka raaka- aineita ovat mekaanisen metsäteollisuuden sivutuotteet kutterinlastu ja sahanpuru. Sylinterin muotoiset pelletit ovat yleensä halkaisijaltaan 6-10 mm ja pituudeltaan 10 - 30 mm. Tässä diplomityössä tarkastellaan pellettiketjua valmistuksesta loppukäyttöön. Työ sisältää valmistuksen, kuljetuksen ja käytön niin tekniset puolet, kuin taloudelliset näkökohdatkin. Myös muiden maiden pellettimarkkinoiden tilanne tuodaan esille. Työn lopussa kuvataan muutama case-esimerkki onnistuneista pellettiketjuista. Suomessa puupellettimarkkinoiden kehitys alkoi 1998 Vöyrissä auenneen pellettitehtaan myötä. Pellettien tuotanto ja kulutus ovat sen jälkeen kasvaneet nopeasti ja nyt vuonna 2001 pellettien tuotantokapasiteetti on 150 000 t/a. Pellettimarkkinoiden nopea kehitys Suomessa perustuu öljyn korkeaan hintaan, käytön helppouteen ja ympäristöystävällisyyteen. Käyttölaitteistojen yleistyessä ja jakelun tehostuessa pellettiliiketoiminta tulee vahvistamaan asemaansa entisestään Suomessa

Pellettien laatu ja ominaisuudet eri raaka-aineilla ja niiden seoksilla

Diplomityö tehtiin osana Vapon toteuttamaa monivuotista pelletin kehitysohjelmaa. Kehitysohjelma koostuu useista pienemmistä osaprojekteista, jotka täydentävät toinen toisiaan. Pellettien raaka-ainepohjan laajentaminen on eräs näistä osaprojekteista. Tutkimustyön tavoitteena oli selvittää erilaisten potentiaalisten bioraaka-aineiden soveltuvuutta pelletointiin joko sellaisenaan tai erilaisina seoksina. Raaka-aineiden pelletoitavuutta tutkittiin kenttäolosuhteissa mobiilipelletointilaitoksella. Laitoksen pääkomponentit muodostivat Kahl C 38–780 tasomatriisipuristin, jäähdytin ja täryseula. Pelletointikokeissa tutkittuja raaka-aineita olivat mäntysahanpuru, männynkuori, harvennusranka, haapa, koivu, jyrsinturve ja ruokohelpi. Raaka-aineiden irtotiheys käyttökosteudessa vaihteli välillä 73–244 kg/m3 ja keskimääräinen kosteuspitoisuus 6,5–15 %. Useissa tapauksissa säkitettyjä raaka-aineita säkkikostutettiin haluttuun kosteuspitoisuuteen ennen pelletointia. Säkkikostutettujen raaka-aineiden kosteuspitoisuudet vaihtelivat tällöin välillä 12–14 m- %. Valtaosa tutkituista raaka-aineista ja niiden seoksista pystyttiin pelletoimaan puristimen matriisilla 8/40 mm, jossa puristuskanavan halkaisija oli 8 mm ja kanavan suoran osan pituus 40 mm. Vaikeuksia tuotti ainoastaan pelkän koivupurun ja ruokohelven pelletointi. Käytetty matriisi oli kanavapituudeltaan liian pitkä koivupurun pelletointiin nostaen puristusvastuksen suureksi. Ruokohelven pelletoinnin vaikeudet johtuivat pääasiassa pelletointiin liian karkeasta raaka-aineesta. Myös matriisia 8/55 mm kokeiltiin, mutta se osoittautui liian ”tiukaksi” valtaosalle puuraaka-aineista. Ainoastaan jyrsinturpeen pelletointi onnistui tällä matriisilla. Männynkuoren pelletointia ei matriisilla 8/55 mm yritetty. Kenttäkokeissa valmistetuista pelleteistä määritettiin erilaisia ominaisuuksia, kuten keskipituus, kosteuspitoisuus, irtotiheys, hienoaineksen määrä ja käsittelykestävyys. Lujuus mitattiin sekä Ligno-testillä että CEN-rummutuslujuuden määrityksellä. Lisäksi pelleteille määritettiin alkuaineanalyysi, tuhkapitoisuus ja lämpöarvo ENAS Oy:n laboratoriossa Jyväskylässä. Ligno-testauksessa parhaimman luokan pelletin tulee yltää arvoon 97,5 %. Pelletoitaessa raaka-aineita ja niiden seoksia tasomatriisikoneella sopivalla matriisilla yllettiin usein näihin tai parempiin tuloksiin. Puumateriaaleilla raaka-aineen optimaalinen lähtökosteus oli välillä 12–14 m- % ja turpeella sekä ruokohelvellä 14–16 m- %. Pelletointi onnistui tällöin vaivattomasti, kunhan sopivat puristimen ajoparametrit oli löydetty. Pellettiä alkoi muodostua matriisin puristuskanavien lämpötilan kohotessa noin 70 ºC. Pellettien lämpötila stabiilitilanteessa heti pelletoinnin jälkeen oli useissa tapauksissa 80–90 ºC. Pelletoinnin aikainen tehontarve vaihteli välillä 90–150 kWh/t, ollen suurimmillaan irtotiheydeltään keveillä materiaaleilla. Raaka-aineen suuri partikkelikoko kasvatti puristimen tehontarvetta. Tämä havaittiin selvästi lisättäessä karkeaa ruokohelpisilppua eri raaka-aineiden joukkoon. Kestävyydeltään erinomaisia pellettejä saatiin, kun raaka-aineena oli jyrsinturve, harvennusranka tai mäntypuru. Varsinkin jyrsinturpeen ja harvennusrangan seoksesta valmistetut pelletit osoittautuivat erittäin kestäviksi. Myös jyrsinturpeen ja ruokohelven sekä mäntypurun ja ruokohelven seoksien pelleteille määritettiin hyviä kestävyysarvoja. Männynkuoresta valmistetut pelletit jäivät Ligno-testauksessa kestävyydeltään alle 97,5 % rajan. Pääsyynä tähän oli kuoren pelletointiin käytetyn matriisin 8/40 mm liian lyhyet puristuskanavat.

Development and in vitro evaluation of coated pellets containing chitosan to potential colonic drug delivery

In this work pellets containing chitosan for colonic drug delivery were developed. The influence of the polysaccharide in the pellets was evaluated by swelling, drug dissolution and intestinal permeation studies. Drug-loaded pellets containing chitosan as swellable polymer were coated with an inner layer of Kollicoat® SR 30 D and an outer layer of the enteric polymer Kollicoat® MAE 30 DP in a fluidized-bed apparatus. Metronidazole released from pellets was assessed using Bio-Dis dissolution method. Swelling, drug release and intestinal permeation were dependent on the chitosan and the coating composition. The drug release data fitted well with the Weibull equation, indicating that the drug release was controlled by diffusion, polymer relaxation and erosion occurring simultaneously. The film coating was found to be the main factor controlling the drug release and the chitosan controlling the drug intestinal permeation. Coated pellets containing chitosan show great potential as a system for drug delivery to the colon. © 2012 Elsevier Ltd.

Influence of the indium concentration on microstructural and electrical properties of proton conducting NiO-BaCe0.9-xIn xY0.1O3-δ cermet anodes for IT-SOFC application

Optimization of the major properties of anodes based on proton conductors, such as microstructure, conductivity and chemical stability, is yet to be achieved. In this study we investigated the influence of indium on the chemical stability, microstructural and electrical characteristics of proton conducting NiO-BaCe0.9-xInxY0.1O 3-δ (NiO-BCIYx) anodes. Four compositions of cermet anode substrates NiO-BCIYx were prepared using the method of evaporation and decomposition of solutions and suspensions (EDSS). Sintered anode substrates were reduced and their microstructural and electrical properties were examined before and after reduction as a function of the amount of indium. Anode substrates tested on chemical stability in the CO2 atmosphere showed high stability compared to anode substrates based on commonly used doped barium cerates. Microstructural properties of the anode pellets before and after testing in CO2 were investigated using X-ray diffraction analysis. Impedance spectroscopy measurements were used for evaluation of electrical properties of the anode pellets and the conductivity values of reduced anodes of more than 14 S cm-1 at 600 °C confirmed percolations through Ni particles. Under fuel cell operating conditions, the cell with a Ni-BCIY20 anode achieved the highest performance, demonstrating a peak power density 223 mW/cm2 at 700 °C confirming the functionality of Ni-BCIY anodes.© 2013 Elsevier B.V. All rights reserved.

Incorporação de probióticos na dieta para juvenis de tilápias-do-nilo: Parâmetros hematológicos, imunológicos e microbiológicos

Probiotics are generally considered as live microorganisms which, when administered in adequate amounts, confer a health benefit to the host. The processing method of diet and the form of inclusion of probiotic can interfere in hematological, immunological and microbiological parameters in fish. The aim was to estimate the hematological, immunological and microbiological parameters in juveniles of Nile tilapia, fed probiotic, included before and after the process of pelletization and extrusion. The experimental design was completely randomized, with five treatments: pelleted diet without probiotic, pelleted diet with inclusion of probiotic before and after processing, extruded feed without probiotic and extruded feed with inclusion of probiotic after processing and five replications. Two hundred and fifty fish were distributed in 25 aquaria (20 L) and fed for 63 days. The blood composition (red and white) showed no significant differences except mean corpuscular hemoglobin concentration of control when compared to other treatments. The phagocytic capacity of the animals that had received the extruded diet supplemented with probiotic was significantly higher when compared to the other treatments. However, there were no differences between the treatments regarding to the phagocytic index. Fish fed the extruded diet exhibited significant improvement in the nonspecific immunity. The probiotic bacteria colonized the intestine, since it was possible to recover them. We can affirm that these fishes remained healthy, because the hematological parameters were not altered during the experimental. The study shows that any form type of inclusion in the feed tested (before or after and after pelletizing extrusion) may be easily used by the fish farmer.

Texture profile and correlation between sensory and instrumental analyses on extruded snacks

Instrumental texture analysis on extruded snacks is widely applied, however there is no scientific consensus about the test and probe types that can be correlated with the sensory texture of snacks. Eleven commercial extruded snacks of different shapes were evaluated instrumentally using different probes and sensorially through descriptive analysis. The snack texture was described using the attributes of hardness, crispness, adhesiveness, fracturability and chewiness. Cylindrical snacks were described through crispness and fracturability, pelleted and shell-shaped snacks by chewiness and ring-shaped snacks by adhesiveness and hardness. Hardness and adhesiveness were correlated with a Warner-Bratzler test using a V shape probe (r = 0.718 and r = 0.763, respectively), while fracturability and chewiness were correlated with a Warner-Bratzler test using a guillotine (r = 0.776 and r = 0.662, respectively). The fairly strong good correlations enable application of these instrumental tests as an indication of the sensory texture of extruded snacks. © 2013 Elsevier Ltd. All rights reserved.

Organofilização de uma Mg-bentonita da bacia do Parnaíba-Sul do Maranhão e sua utilização em poli (metacrilato de metila)

Bentonitas são argilas que tem como seu principal constituinte argilominerais do grupo da esmectita, predominantemente montmorillonita. De acordo com o cátion predominante no espaço intercamada da esmectita, a bentonita pode ser classificada como sódica, cálcica ou magnesiana. Essas argilas possuem vasta aplicação industrial, como fluidos de perfuração, pelotização, moldes de fundição, dentre outros. Para algumas aplicações mais específicas e que agregam maior valor ao produto final, como na síntese de nanocompósitos polímero/argila, faz-se necessário à intercalação de íons orgânicos na intercamada do argilomineral. No Brasil, a produção industrial de argilas organofílicas é pequena e voltada para os mercados de tintas, graxas e resinas de poliéster. Empresas do setor de bentonitas, que ainda não estão produzindo esse tipo de material, vêm mostrando crescente interesse nesta aplicação. Dentro desse contexto, este trabalho buscou avaliar o potencial da Bentonita Formosa, uma Mg-bentonita recentemente descrita e relativamente abundante no nordeste do Brasil, na produção de argilas organofílicas e sua aplicação em síntese de nanocompósitos polímero/argila. Para isso, foram realizadas sínteses variando a concentração dos íons surfactantes hexadeciltrimetilamônio (HDTMA⁺) e dodeciltrimetilamônio (DTMA⁺) em 0,7, 1,0 e 1,5 vezes o valor de CEC, com tempo de reação de 12 horas e variação de temperatura de 25 ºC e 80 ºC. A Mg-Bentonita in natura e ativada com carbonato de sódio foi utilizada como material de partida. Tanto o material de partida como as argilas organofílicas obtidas foram caracterizadas por DRX, DTA/TG e IV. As argilas que apresentaram melhores resultados de intercalação foram utilizadas nas proporções de 1%, 3% e 10% para a síntese de nanocompósitos poli(metacrilato de metila) (PMMA)/argila. As análises de DRX confirmaram a intercalação dos íons orgânicos no espaço intercamada da Mg-esmectita com e sem ativação. Com os resultados de IV foi possível observar que a razão de confôrmeros gauche/trans diminui com o aumento do espaçamento basal. Os resultados de DTA/TG confirmaram a estabilidade térmica das argilas organofílicas à temperatura máxima de 200 °C, o que possibilita a utilização desse material em síntese de nanocompósitos polímero/argila obtidos por processo de fusão. A análise de DRX confirmou a intercalação do PMMA no espaço intercamada da Mg-esmectita em todos os nanocompósitos produzidos. Com as análises de DSC foi possível observar o aumento da temperatura de transição vítrea para todos os nanocompósitos, quando comparados com PMMA puro. Com isso, é possível concluir que a Mg-Bentonita pode ser intercalada com íons alquilamônio, sem a necessidade prévia de ativação sódica, formando argilas organofílicas, assim como sua utilização em síntese de nanocompósitos. Essa possibilidade de utilização da Mg-bentonita in natura pode representar uma importante diferença em termos de custos de processo, na comparação com as bentonitas cálcicas existentes no Brasil, ou mesmo as importadas, que precisam ser ativadas durante o beneficiamento. Finalmente, acredita-se que a pesquisa deve avançar com a avaliação das propriedades mecânicas dos nanocompósitos produzidos neste trabalho, visando as diferentes possibilidades de aplicações desses materiais.

Development of a Mechanism and Process to Continuously Produce Spherical, Torrefied Biomass

Thesis (Master, Mechanical and Materials Engineering) -- Queen's University, 2016-06-17 02:15:25.215

DEVELOPMENT OF A MECHANISM AND PROCESS TO CONTINUOUSLY PRODUCE SPHERICAL, TORREFIED BIOMASS PELLETS

A recently developed novel biomass fuel pellet, the Q’ Pellet, offers significant improvements over conventional white pellets, with characteristics comparable to those of coal. The Q’ Pellet was initially created at bench scale using a proprietary die and punch design, in which the biomass was torrefied in-situ¬ and then compressed. To bring the benefits of the Q’ Pellet to a commercial level, it must be capable of being produced in a continuous process at a competitive cost. A prototype machine was previously constructed in a first effort to assess continuous processing of the Q’ Pellet. The prototype torrefied biomass in a separate, ex-situ reactor and transported it into a rotary compression stage. Upon evaluation, parts of the prototype were found to be unsuccessful and required a redesign of the material transport method as well as the compression mechanism. A process was developed in which material was torrefied ex-situ and extruded in a pre-compression stage. The extruded biomass overcame multiple handling issues that had been experienced with un-densified biomass, facilitating efficient material transport. Biomass was extruded directly into a novel re-designed pelletizing die, which incorporated a removable cap, ejection pin and a die spring to accommodate a repeatable continuous process. Although after several uses the die required manual intervention due to minor design and manufacturing quality limitations, the system clearly demonstrated the capability of producing the Q’ Pellet in a continuous process. Q’ Pellets produced by the pre-compression method and pelletized in the re-designed die had an average dry basis gross calorific value of 22.04 MJ/kg, pellet durability index of 99.86% and dried to 6.2% of its initial mass following 24 hours submerged in water. This compares well with literature results of 21.29 MJ/kg, 100% pellet durability index and <5% mass increase in a water submersion test. These results indicate that the methods developed herein are capable of producing Q’ Pellets in a continuous process with fuel properties competitive with coal.

Utilisation d’arbres de faible vigueur provenant de forêts feuillues tempérées comme matière première pour la fabrication de granules de bois

La présente étude avait pour objectif de contribuer à une meilleure compréhension de la granulation des bois feuillus par l’évaluation de la possibilité technique de transformer des bois feuillus de faible vigueur (l’érable à sucre et le bouleau jaune) en granules conventionnels et granules de haute qualité, un type prometteur de transport énergétique. Trois études individuelles ont été réalisées et présentées dans cette thèse. La première étude visait à déterminer s’il y a des changements de teneur en extractibles, cendres, et lignine du bois entre les classes de vigueur des arbres. Les teneurs plus élevées en extractibles et en lignine dans les arbres peu vigoureux ont suggéré que ces derniers sont plus appropriés par rapport aux arbres vigoureux pour la conversion en biocombustibles solides. La deuxième étude visait à optimiser des procédés de granulation des bois feuillus. L’étude a porté sur l’influence des paramètres du procédé (la température et la force de compression) et des caractéristiques de la matière première (la taille des particules et la teneur en humidité) sur les propriétés physiques et mécaniques des granules de bois. Le procédé de granulation doit être effectué à une température d’environ 100 °C pour minimiser la force de friction dans le granulateur et à une teneur en humidité d’environ 11,2% pour maximiser la masse volumique et la résistance mécanique des granules produites. Cette étude a également confirmé que les arbres de faible qualité sont plus appropriés pour la fabrication de granules de bois que les arbres vigoureux. La troisième étude visait l’élaboration de granules de haute qualité. L’eau chaude à température élevée a été utilisée pour modifier les propriétés de la matière première avant granulation. Les caractéristiques de granulation du matériau traité ont été significativement améliorées. Les granules produites ont montré des propriétés améliorées incluant une plus faible teneur en cendres, une plus haute densité énergétique, une meilleure résistance à l’eau, et une meilleure résistance mécanique. Les résultats obtenus de toutes ces études ont démontré la nécessité de bien connaître les fondements de la granulation des bois feuillus et les solutions pratiques pour l’utilisation d’arbres feuillus de faible qualité, le premier peut être applicable pour le développement de procédés de granulation et le dernier peut contribuer à long terme à la restauration des forêts feuillues dégradées en termes de santé des forêts et de leur valeur.