Spelling suggestions: "subject:"biomass - gasification"" "subject:"biomass - basification""
81 |
Biomethane via Woodroll® - Investigation of Revenues & Profitability Analysis / Biometan via Woodroll - Utredning av intäkter och lönsamhetsanalysAndersson Krohn, Robert January 2016 (has links)
Woodroll® is a gasification technology developed by Cortus that produces synthetic gas (syngas) from biomass. Syngas can be used in several different applications. One interesting option is to convert it further into biomethane, which can be used as automotive fuel or replace natural gas in gas grids. The revenues and profitability of biomethane production is heavily dependent on policy instruments and support schemes. These subsidies can be either direct, where the producer receives a feed-in tariff for biomethane production, or indirect, where consumption rather than production is stimulated. This work has investigated which revenues that can be expected from biomethane production via Woodrooll® in Sweden, the Netherlands, Germany, the UK, France and Italy, both in terms of amounts and risks. A profitability analysis have also been carried out to preliminary compare the returns in the different countries, where two different scenarios for different revenues have been analyzed for two different feedstock prices. The results showed that the Netherlands and Italy provides the potentially highest revenues. However, there are uncertainty factors associated with all cases. Sweden and Germany offers indirect support and negative market trends. The Netherlands and the UK are the only options that provide a feed-in tariff for biomethane production via gasification. In the Netherlands the tariff can be secured before making investment decision but is only disbursed for 12 years. The UK offers a fixed feed-in tariff for 20 years but the tariff is secured first after plant start-up and the tariff may be reduced on a quarterly basis. In fact, the tariff has been reduced with 40 % over the last 24 months, but there are discussions on introducing a separate tariff for gasification. Italy has the support schemes that potentially offer the highest revenues, but gasification is currently not eligible for support. The latter also holds for France, which may be an interesting case in the future. If risk is to be minimized, Cortus may either focus on the Netherlands or await the discussions in the UK and France on introducing a gasification tariff. The work on standardization of biomethane use should also be followed since Italy offers the potentially highest return of the investigated countries. It is also recommended to look further for other cases. The best-case scenario for the risk averse is the one that provides a fixed tariff for 20 years and in which the tariff can be secured before an investment decision is taken. / Woodroll® är en förgasningateknik som utvecklats av Cortus som producerar syntesgas (syngas) från biomassa. Det finns en rad olika användningsområden för gasen. Ett intressant sådant är att omvandla den till biometan, vilket kan användas som drivmedel eller ersätta naturgas i gasnät. Dock så är intäktern och lönsamheten starkt beroende av stödsystem. Dessa subventioner kan antingen vara i form av en inmatningstariff, där biometanproducenten får en fast peng för biometanproduktion, eller i form av indirekt stöd där konsumtion snarare än produktion stimuleras. I detta arbete har det utretts vilka intäkter som kan förväntas för biometan-produktion genom Woodroll® i Sverige, Nederländerna, Tyskland, Storbritanninen, Frankrike och Italien, både i termer av belopp och risk. En lönsamhetsanalys har också gjorts för att preliminärt jämföra avkastningen för de olika länderna. Två olika scenarier för olika intäkter har analyserats för två olika råvarupriser. Resultatet visade att samtliga länder kan erbjuda attraktiv avkastning. Dock är samtliga fall förknippade med osäkerhetsfaktorer. Sverige och Tyskland erbjuder indirekt stöd och negativa marknadstrender. Nederländerna och Storbritannien är de enda alternativen som ger en feed-in-tariff för biometanproduktion. I Nederländerna kan tariffen säkras innan investeringsbeslut fattats men betalas endast i 12 år. Storbritannien ger en fast tariff i 20 år men kan justeras kvarstalsvis och nivån säkras först efter uppstart av anläggningen. Tariffen har reducerats med 40 % de senaste 24 månaderna, men det pågår diskussioner om att introducera en särskild tariff för förgasning. Italien erbjuder stödsystemet som ger högst potentiella intäkter men biometan från förgasning är inte berättigat för stödet. Det senare gäller också för Frankrike som kan bli ett intressant fall i framtiden. Om det önskas att minimera risken så bör Cortus fokusera antingen på Nederländerna eller invänta diskussionerna om förgasningstariffen i Storbritannien och Frankrike. Arbetet kring standardisering av biometan-användning bör också följas eftersom Italien erbjuder de potentiellt högsta intäkterna. Det rekommenderas också att Cortus tittar vidare på andra alternativ. Det bästa fallet för den risk-aversiva är fallet som ger en fast tariff i 20 år och där stödet kan säkras innan investeringsbeslut fattas.
|
82 |
Expermental and Modeling Studies on the Generation of Hydrogen Rich Syngas through Oxy-Steam Gasification of BiomassSandeep, Kumar January 2016 (has links) (PDF)
The present work focuses on the study of biomass gasification process for generating hydrogen rich synthetic gas with oxy-steam as reactants using experiments and modeling studies. Utilization of the syngas as a fuel in general applications like fuel cells, Fischer-Tropsch FT) process and production of various chemicals like DME, etc. are being considered to meet the demand for clean energy.
This study comprises of experiments using an open top down draft reactor with oxygen and steam as reactants in the co-current configuration. Apart from the standard gasification performance evaluation; parametric study using equivalence ratio, steam-to-biomass ratio as major variables towards generation of syngas is addressed towards controlling H2/CO ratio. The gasification process is modeled as a packed bed reactor to predict the exit gas composition, propagation rate, bed temperature as a function of input reactants, temperature and mass flux with variation in thermo-physical properties of biomass. These results are compared with the present experiments as well as those in literature.
Experiments are conducted using modified open top downdraft configuration reactor with lock hoppers and provision for oxy-steam injection, and the exit gas is connected to the cooling and cleaning system. The fully instrumented system is used to measure bed temperatures, steam and exit gas temperature, pressures at various locations, flow rates of fuel, reactants and product gas along with the gas composition. Preliminary investigations focused on using air as the reactant and towards establishing the packed bed performance by comparing with the experimental results from the literature and extended the study to O2-N2 mixtures. The study focuses on determining the propagation rate of the flame front in the packed bed reactor for various operating conditions. O2 is varied between 20-100% (vol.) in a mixture of O2-N2 to study the effect of O2 fraction on flame propagation rate and biomass conversion. With the increase in O2 fraction, the propagation rates are found to be very high and reaching over 10 mm/s, resulting in incomplete pyrolysis and poor biomass conversion. The flame propagation rate is found to vary with oxygen volume fraction as XO22.5, and stable operation is achieved with O2 fraction below 30%.
Towards introducing H2O as a reactant for enhancing the hydrogen content in the syngas and also to reduce the propagation rates at higher ER, wet biomass is used. Stable operating conditions are achieved using wet biomass with moisture-to-biomass (H2O:Biomass) ratio between 0.6 to 1.1 (mass basis) and H2 yield up to 63 g/kg of dry biomass amounting to 33% volume fraction in the syngas. Identifying the limitation on the hydrogen yield and the criticality of achieving high quality gas; oxy-steam mixture is introduced as reactants with dry biomass as fuel. An electric boiler along with a superheater is used to generate superheated steam upto 700 K and pressure in the range of 0.4 MPa. Steam-to-biomass ratio (SBR) and ER is varied with towards generating hydrogen rich syngas with sustained continuous operation of oxy-steam gasification of dry biomass. The results are analysed with the variation of SBR for flame propagation rates, calorific value of product syngas, energy efficiency, H2 yield per kg of biomass and H2/CO ratio.
Hydrogen yield of 104 g per kg of dry casuarina wood is achieved amounting to 50.5% volume fraction in dry syngas through oxy-steam gasification process compared to air gasification hydrogen yield of about 40 g per kg of fuel and 20% volume fraction. First and second law analysis for energy and exergy efficiency evaluation has been performed on the experimental results and compared with air gasification. Individual components of the energy input and output are analysed and discussed. H2 yield is found to increase with SBR with the reduction in energy density of syngas and also energy efficiency. Highest energy efficiency of 80.3% has been achieved at SBR of 0.75 (on molar basis) with H2 yield of 66 g/kg of biomass and LHV of 8.9 MJ/Nm3; whereas H2 yield of 104 g/kg of biomass is achieved at SBR of 2.7 with the lower efficiency of 65.6% and LHV of 7.4 MJ/Nm3. The energy density of the syngas achieved in the present study is roughly double compared to the LHV of typical product gas with air gasification. Elemental mass balance technique has been employed to identify carbon boundary at an SBR of 1.5. Controlling parameters for arriving at the desired H2/CO ratio in the product syngas have been identified.
Optimum process parameters (ER and SBR) has been identified through experimental studies for sustained continuous oxy-steam gasification process, maximizing H2 yield, controlling the H2/CO ratio, high energy efficiency and high energy density in the product syngas. Increase in ER with SBR is required to compensate the reduction in O2 fraction in oxy-steam mixture and to maintain the desired bed temperature in the combustion zone. In the range of SBR of 0.75 to 2.7, ER requirement increases from 0.18 to 0.3. The sustained continuous operation is possible upto SBR of 1.5, till the carbon boundary is reached. Operating at high SBR is required for high H2 yield but sustained highest H2 yield is obtained as SBR of 1.5. H2/CO ratio in the syngas increases from 1.5 to 4 with the SBR and depending on the requirement of the downstream process (eg., FT synthesis), suitable SBR and ER combination is suggested. To obtain high energy density in syngas and high energy efficiency, operations at lower SBR is recommended.
The modeling study is the extension of the work carried by Dasappa (1999) by incorporating wood pyrolysis model into the single particle and volatile combustion for the packed bed of particles. The packed bed reactor model comprises of array of single particles stacked in a vertical bed that deals with the detailed reaction rates along with the porous char spheres and thermo-physical phenomenon governed by the mass, species and energy conservation equations.
Towards validating the pyrolysis and single particle conversion process, separate analysis and parametric study addressing the effects of thermo-physical parameters like particle size, density and thermal conductivity under varying conditions have been studied and compared with the available results from literature. It has been found that the devolatilisation time of particle (tc) follows closely the relationship with the particle diameter (d), thermal conductivity (k), density () and temperature (T) as:
The complete combustion of a single particle flaming pyrolysis and char combustion has been studied and validated with the experimental results. For the reactor modeling, energy, mass and species conservation equations in the axial flow direction formulate the governing equations coupled to the detailed single particle analysis. Gas phase reactions involving combustion of volatiles and water gas shift reaction are solved in the packed bed. The model results are compared with the experimental results from wood gasification system with respect to the propagation rate, conversion times, exit gas composition and other bed parameters like conversion, peak bed temperatures, etc.
The propagation rates compare well with experimental data over a range of oxygen concentration in the O2- N2 mixture, with a peak at 10 mm/s for 100 % O2. In the case of oxy-steam gasification of dry biomass, the results clearly suggest that the char conversion is an important component contributing to the bed movement and hence the overall effective propagation rate is an important parameter for co-current reactors. This is further analyzed using the carbon boundary points based on elemental balance technique.
The model predictions for the exit gas composition from the oxy-steam gasification matches well with the experimental results over a wide range of equivalence ratio and steam to biomass ratio. The output gas composition and propagation rates are found to be a direct consequence of input mass flux and O2 fraction in oxy-steam mixture.
The present study comprehensively addresses the oxy-steam gasification towards generating hydrogen rich syngas using experimental and model studies. The study also arrives at the parameters for design consideration towards operating an oxy-steam biomass gasification system. The following flow chart provides the overall aspects that are covered in the thesis chapter wise.
|
83 |
A feasibility study of a CDM compliant small-scale biomass gasification electricity generation project at a Western Cape wine cellarSchumann, Dolf 12 1900 (has links)
Thesis (MBA)--Stellenbosch University, 2008. / ENGLISH ABSTRACT: The goal of this study was to investigate the feasibility of a small-scale biomass gasification system
within the context of a cooperative wine cellar operation in the Western Cape of South Africa.
Central to this goal was the questions whether the time for the implementation of such small-scale
renewable energy technologies in South Africa has arrived, in light of the status quo which has
changed drastically from the days of abundant and cheap coal-based electricity, and whether the
new opportunities afforded by the CDM can help foster financial feasibility.
There are various macro-drivers contributing to the current-day emphasis on renewable energy and
cogeneration projects. The first and most pressing driver is the global climate change imperative,
while the others include the increased aspiration of countries towards energy security, the
realization of the importance of sustainable development and the subsequent renewable energy
policies that falls within the ambit of sustainable development.
Small-scale biomass gasification technology still poses some challenges, particularly when it comes
to the gasification of agricultural residues, as with grape residues in the case of this project. The
most important technical feasibility problem to overcome is the low ash agglomeration temperature
of grape residues reported in the literature. Although the local equipment manufacturer foresees no
problem in this regard with their system design - since they have conducted tests on sunflower seed
residues, which have similar ash properties, without experiencing any agglomeration problems - the
seriousness of this aspect will be confirmed during pilot trials.
In order to be eligible for emissions reduction trading under the CDM, the project must adequately
demonstrate that the emissions reductions are additional to the business-as-usual scenario, in both
the environmental and financial sense. The project will satisfy the environmental additionality
requirement, since in its absence the wine cellar will continue its full reliance on coal-based
electricity from the grid. Financial additionality, in its strictest sense, requires for the project to be
infeasible if it does not pursue CDM participation, which the financial feasibility modeling results
indicated to be true in this case.
A feasibility model was developed to - subject to the input parameter values assumed and basic
assumptions made - be able to assess the financial viability of the project. The main assumptions
were that the private feed-in into the national electricity grid was available to all IPPs, in spite of the
fact that in its Medium Term Power Purchase Program me (MTPPP) of May 2008 Eskom had only
requested expressions of interest from IPPs that had a generating capacity of 5MW and higher to
install private base load capacity. This assumption is commensurate with the country's renewable
energy targets and the official government aim of achieving a 30% contribution from IPPs to the
national electricity mix.
The second assumption was that the 65 to lOOclkWh offered by Eskom in its MTPPP will be
applicable to sub-SMWe IPPs as well (Creamer, 2008), and that this lower bound electricity price of
65clkWh can be applied over the whole project lifetime. Inherent to this assumption is the further
supposition that the progressive decline of electricity prices to an eventual level of 35clkWh by
2018 foreseen by Eskom will not materialize, due both to the sustained pressure an expanding South
African economy will put on the considerable but time-consuming supply-side initiatives launched
by Eskom, and the likelihood for price premiums to be introduced for clean electricity in order to
meet the country's renewable energy targets.
From the assumed input parameter values the initial capital and COM expenditures, operating
revenues and costs over the project lifetime were determined, and then used to calculate the net cash
flows, where after the NPV was computed to serve as the deciding criterion on financial feasibility.
A discount rate of 18% was assumed, corresponding with the subjectively judged risks that the
project posed as a small-scale renewable energy system within the wine cellar operations.
In the case where the project excluded all CDM aspects, the NPV was negative at - ZAR342 573,
but this improved to ZAR325 193 if the project participated in the CDM. Thus it was concluded that
the project will only be financially feasible if it includes CDM participation, and that this positive
contribution can be leveraged by pursuing a programmatic CDM approach. This entails the
development of this project as part of a larger program in which similar projects are implemented as
they arise, up to the official UN limit of 15MWe in total to still qualify as a small-scale program.
The nature of the assumptions that form the backbone of this study indicate that the positive
financial feasibility result in the case where the project includes COM participation will become
practically relevant only over the short- to medium-term as these assumptions become reality in
South Africa. Therefore, although the time for such small-scale renewable energy projects has
clearly not arrived as yet, it would seem that it is indeed around the corner. / AFRIKAANSE OPSOMMING: Die mikpunt van die navorsing was om die lewensvatbaarheid van 'n klein-skaal biomassa
vergassing sisteem binne die konteks van 'n kooperatiewe wynkelder in die Wes-Kaap van Suid-Afrika
te ondersoek. 'n Sentrale aspek was die vrae of die tyd aangebreek het om klein-skaal
volhouhare energie projekte in Suid-Afrika tot uitvoering te bring, gesien in die lig van 'n status
quo wat drasties weg beweeg het van die tydperk toe elektrisiteit volop en goedkoop was, en of die
geleentheid wat die CDM bied sulke projekte finansieel lewensvatbaar kan maak.
Daar is verskeie eksterne makro-drywers wat bydrae tot die huidige fokus op sulke volhoubare
energie projekte. Hieronder tel globale klimaatsverandering as die dringendste drywer, terwyl die
res onder andere die hernuwe strewe van lande tot verbeterde energie-sekuriteit, die besef van die
belangrikheid van volhoubare ontwikkeling en die daaropvolgende volhoubare energie beleid
stappe insluit.
Daar bestaan nog etlike tegniese uitdagings tot die toepassing van klein-skaal biomassa vergassing
tegnologie, spesifiek met betrekking tot die vergassing van afval landbou byprodukte, soos wat die
geval is met druiwe afval in hierdie projek. Die belangrikste tegniese uitvoerbaarheids-aspek wat
aandag verg is die lae smeltpunt van druifafval-as wat in die literatuur rapporteer word. Alhoewel
die plaaslike toerustings-vervaardiger nie enige probleme in hierdie verhand voorsien nie, aangesien
toetse met sonneblom afval - met as-eienskappe rofweg identies aan die van druiwe-afval - geen
smelting van die as getoon het nie, sal dit tog nogsteeds aan verdere toetse onderwerp word.
Vir die projek om te kwalifiseer as geskik vir verhandeling in kweekhuisgas vermindering deur
middel van die COM, moet dit voldoende bewys kan word dat alle uitlaatgas vermindering
addisioneel is tot wat die geval sou wees in die gewone gang van besigheid. Hierdie addisionaliteit
is relevant in beide 'n omgewings- en finansiele sin. Hierdie projek sal orngewings-addisionaliteit
bevredig deurdat die wynkelder in sy afwesigheid volkome afhanklik van die steenkool-gebaseerde
elektrisiteit vanaf die nasionale netwerk sou bly, terwyl finansiele addisionaliteit bewys is deur die
finansiele lewensvatbaarheids-model wat getoon het dat die projek slegs ekonomies uitvoerbaar sal
wees indien dit CDM deelname insluit.
Die lewensvatbaarheids-model is ontwikkel om die ekonomiese uitvoerbaarheid van die projek te
evalueer, onderworpe aan die aangenome inset parameter waardes en basiese aannames in die
studie. Die hoof-aanname was naamlik dat privaat terugvoer in die nasionale elektrisiteits-netwerk
vir alle grootte IPPs moontlik is, ten spyte van die feit dat Eskom se MTPPP van Mei 2008 slegs
kapasiteite van 5MW en groter aanvaar bet. Hierdie aanname is gebaseer op Suid-Afrika se
volhoubare energie teikens en die regering se offisiele mikpunt om 30% van alle krag-voorsiening
vanaf IPPs te bekom.
Die tweede hoof-aanname was dat die 65 tot 100clkWh wat Eskom in sy MTPPP aangebied het,
ook van toepassing sal wees op sub-SMW IPPs (Creamer, 2008), en dat die laer prys-limiet van
65c/kWb oor die hele projek-leeftyd toegepas kon word. Inherent tot hierdie aanname is die verdere
veronderstelling dat die progressiewe daling in elektrisiteits-pryse tot 'n eventuele vlak van
35clkWh voorsien deur Eskom nie sal realiseer nie, beide as gevolg van die volgehoue druk wat die
groeiende Suid-Afrikaanse ekonomie op die aansieniike, maar tydrowende, opwekkings-kapasiteit
uitbreidings van Eskom behoort te plaas, en ook die hoe waarskynlikheid dat prys premiums vir
skoon elektrisiteit ingestel word sodat Suid-Afrika sy volboubare energie telkens kan bereik.
Die aanvanklike kapitaal en CDM uitgawes, en bedryfsuitgawes en - inkomstes oor die projekleeftyd
is vanaf die aangenome inset parameter waardes afgelei, waarop die NPV van die projek
uitgewerk is om te dien as die beslissende maatstaf van ekonomiese haalbaarheid. 'n Diskontokoers
van 18% is gebruik, ooreenstemmend met die subjektief beraamde risikos wat die projek
inhou as 'n klein-skaal volhoubare energie sisteem.
Die resultate van die finansiele lewensvatbaarheids-model het getoon dat in die geval waar die
projek geen CDM aspekte bevat nie, die NPV hoogs negatief sou wees met 'n waarde van
-ZAR342 573, terwyl dit verbeter na ZAR325 193 as die projek CDM deelname insluit. Die
gevolgtrekking is dus gemaak dat die spesifieke projek slegs ekonomies haalbaar sal wees indien dit
wel CDM deelname insluit, en dat hierdie positiewe finansiele bydrae van die CDM geoptimaliseer
kan word deur 'n programmatiese CDM benadering te volg. Dit behels die ontwikkeling van die
projek as deel van 'n groter program waarin soortgelyke projekte mettertyd geimplementeer word
soos hulle ontstaan, tot by die offisiele VN limiet van 15MWe om sodoende nog te kwalifiseer as 'n
algehele klein-skaalse program.
Die aard van die hoof-aannames in hierdie studie is indikatief dat die positiewe finansiele
lewensvatbaarheid in die geval waar die projek CDM deelname insluit, eers oor die kort- tot
medium-termyn prakties relevant sal word soos die aannames bevredig word. Dus, alhoewel die era
van klein-skaalse volhoubare energie projekte nog nie aangebreek het in Suid-Afrika nie, lyk dit tog
asof dit om die draai is.
|
84 |
Nouvelles stratégies catalytiques pour la gazéification de la biomasse : génération in-situ de nanoparticules à base de nickel ou de fer au cours de l'étape de pyrolyse / New catalytic strategies for biomass gasification : in-situ generation of nickel- or iron-based nanoparticles during the pyrolysis stageRichardson, Yohan 07 October 2010 (has links)
L'objectif de ce travail est d'étudier une stratégie catalytique originale, consistant à insérer par imprégnation, au sein de la matrice lignocellulosique du bois, un sel métallique de Ni ou Fe, dont les phases catalytiquement actives pour la conversion des goudrons sont générées in-situ au cours de l'étape de pyrolyse. La caractérisation des échantillons de bois imprégné révèle que l'insertion des cations métalliques fait intervenir des mécanismes d'adsorption électrostatique, d'échange ionique et de complexation au sein des hémicelluloses, de la lignine et des microfibrilles de cellulose, assurant un état élevé de dispersion du métal dans la matrice lignocellulosique. L'étude de l'évolution des espèces de Ni au cours de la pyrolyse du bois met en évidence la formation de nanoparticules (NPs) de Ni0 quasi-monocristallines dans la gamme de température 400-500°C, les atomes de carbone jouant le rôle d'agent réducteur. Dans la même gamme de température, les espèces de Fe sont transformées en NPs de FeOx amorphes. Les tests de pyrolyse à 700°C révèlent que le nickel est plus efficace pour augmenter la production de H2 et réduire la formation d'hydrocarbures aromatiques, tandis que le fer est plus performant pour réduire la production totale de goudrons. D'un point de vue mécanistique, la présence des espèces métalliques, très dispersées dans la matrice lignocellulosique, impacte considérablement les mécanismes primaires de pyrolyse. De plus, les réactions secondaires de pyrolyse sont fortement modifiées par la génération in-situ des NPs de Ni0 et de FeOx, considérées comme les phases actives pour les réactions de conversion des goudrons et la réaction du gaz à l'eau. / This exploratory research work aimed at studying an original catalytic strategy for biomass gasification which consists in inserting into the lignocellulosic matrix of wood, by impregnation, a salt of Ni or Fe whose catalytically active phases for tar conversion reactions are generated in-situ during the pyrolysis stage. The characterization of the metal impregnated wood samples reveals that electrostatic adsorption, ion-exchange and metal complexation within hemicelluloses, lignin and cellulose microfibrills are involved in the mechanisms of metal cations insertion, resulting in a very high metal dispersion into the lignocellulosic matrix. The study of the nickel species evolution during wood pyrolysis demonstrates the formation of quasi-monocristalline Ni0 nanoparticles (NPs) in the temperature range 400-500°C, the carbon atoms acting as the reducing agent. In the same temperature range, the Fe species are transformed into amorphous FeOx NPs. The pyrolysis tests performed at 700°C reveal that the nickel catalyst is more efficient for enhancing H2 production and reducing the formation of aromatic hydrocarbons, whereas the iron catalyst exhibits better performances for reducing total tar production. From a mechanistic standpoint, it is suggested that the presence of highly dispersed metal species into the lignocellulosic matrix strongly impacts the mechanisms of primary pyrolysis. Moreover, the secondary pyrolysis reactions are strongly modified by the in-situ generation of Ni0 and FeOx NPs considered as the active phases for tar conversion and water gas shift reactions. Potential interests of the new nanocomposite materials Ni0/C and FeOx/C as obtained are discussed.
|
85 |
Metodologia para o PIR em ambiente corporativo para o recurso energético da gaseificação de biomassa. / IRP metodology whithin corporate enviroment for biomass gasification.Kinto, Oscar Tadashi 28 September 2012 (has links)
O objetivo deste trabalho é aplicar a metodologia do Planejamento Integrado de Recursos energéticos (PIR) dentro do ambiente corporativo. Para estudo de caso foi escolhida uma indústria de papel e celulose, por se tratar de uma das indústrias de maior consumo energético, e a região onde ela está instalada, o município de Suzano. Inicialmente, procurou-se descrever o processo produtivo em uma indústria de papel e celulose. Para este trabalho foi analisado somente os recursos do lado da oferta. Além dos recursos tradicionais, que são a caldeira de biomassa, a caldeira de gás natural/óleo combustível e as caldeiras de recuperação, foi incluída uma nova tecnologia, a gaseificação de biomassa. Foram descritas as tecnologias de gaseificação disponíveis e mostrado o seu estado da arte. Dentro dessas tecnologias, há uma aplicação que busca substituir as tecnologias atuais de caldeira de recuperação, a gaseificação de licor negro. / The purpose of this study was to apply the Integrated Resources Planning for Energy (IRP) methodology within corporate environment. A study of case of pulp and mill industry was chosen, because it is one of largest energy consumption industries, and the region that was studied was Suzano. Initially we described the industrial process of pulp and mill factory. This study we will analyze only the features of Supply Side Resources. In addition to the traditional power supplies which are biomass boiler, natural gas/fuel oil boiler and recovery boiler, we include a new technology, biomass gasification. We described the technologies available for gasification and show the state of art of this technology. Within these technologies, we have an special application the seeks to replace currently technology of recovery boiler, Black Licor Gasification.
|
86 |
Metodologia para o PIR em ambiente corporativo para o recurso energético da gaseificação de biomassa. / IRP metodology whithin corporate enviroment for biomass gasification.Oscar Tadashi Kinto 28 September 2012 (has links)
O objetivo deste trabalho é aplicar a metodologia do Planejamento Integrado de Recursos energéticos (PIR) dentro do ambiente corporativo. Para estudo de caso foi escolhida uma indústria de papel e celulose, por se tratar de uma das indústrias de maior consumo energético, e a região onde ela está instalada, o município de Suzano. Inicialmente, procurou-se descrever o processo produtivo em uma indústria de papel e celulose. Para este trabalho foi analisado somente os recursos do lado da oferta. Além dos recursos tradicionais, que são a caldeira de biomassa, a caldeira de gás natural/óleo combustível e as caldeiras de recuperação, foi incluída uma nova tecnologia, a gaseificação de biomassa. Foram descritas as tecnologias de gaseificação disponíveis e mostrado o seu estado da arte. Dentro dessas tecnologias, há uma aplicação que busca substituir as tecnologias atuais de caldeira de recuperação, a gaseificação de licor negro. / The purpose of this study was to apply the Integrated Resources Planning for Energy (IRP) methodology within corporate environment. A study of case of pulp and mill industry was chosen, because it is one of largest energy consumption industries, and the region that was studied was Suzano. Initially we described the industrial process of pulp and mill factory. This study we will analyze only the features of Supply Side Resources. In addition to the traditional power supplies which are biomass boiler, natural gas/fuel oil boiler and recovery boiler, we include a new technology, biomass gasification. We described the technologies available for gasification and show the state of art of this technology. Within these technologies, we have an special application the seeks to replace currently technology of recovery boiler, Black Licor Gasification.
|
87 |
RhPt and Ni based catalysts for fuel reforming in energy conversionGonzález Arcos, Angélica Viviana January 2015 (has links)
Although current trends in global warming are of great concern, energy demand is still increasing, resulting in increasing pollutant emissions. To address this issue, we need reliable renewable energy sources, lowered pollutant emissions, and efficient and profitable processes for energy conversion. We also need to improve the use of the energy, produced by existing infrastructure. Consequently, the work presented in this thesis aims at investigating current scientific and technological challenges in energy conversion through biomass gasification and the alternative use of fossil fuels, such as diesel, in the generation of cleaner electricity through auxiliary power units in the transport sector. Production of chemicals, syngas, and renewable fuels is highly dependent on the development and innovation of catalytic processes within these applications. This thesis focuses on the development and optimization of catalytic technologies in these areas. One of the limitations in the commercialization of the biomass gasification technology is the effective catalytic conversion of tars, formed during gasification. Biomass contains high amounts of alkali impurities, which pass on to the producer gas. Therefore, a new material with alkali tolerance is needed. In the scope of this thesis, a new catalyst support, KxWO3 – ZrO2 with high alkali resistance was developed. The dynamic capability of KxWO3 – ZrO2 to store alkali metals in the crystal structure, enhances the capture of alkali metals "in situ". Alkali metals are also important electronic promoters for the active phase, which usually increases the catalysts activity and selectivity for certain products. Experimental results show that conversion of 1-methylnaphathalene over Ni/KxWO3 – ZrO2 increases in the presence of 2 ppm of gas-phase K (Paper I). This support is considered to contribute to the electronic equilibrium within the metal/support interface, when certain amounts of alkali metals are present. The potential use of this support can be extended to applications in which alkali "storage-release" properties are required, i.e. processes with high alkali content in the process flow, to enhance catalyst lifetime and regeneration. In addition, fundamental studies to understand the adsorption geometry of naphthalene with increasing temperature were performed in a single crystal of Ni(111) by STM analyses. Chapter 9 presents preliminary studies on the adsorption geometry of the molecule, as well as DFT calculations of the adsorption energy. In relation to the use of clean energy for transport applications, hydrogen generation through ATR for FC-APUs is presented in Papers II to V. Two promoted RhPt bimetallic catalysts were selected in a previous bench scale study, supported on La2O3:CeO2/d – Al2O3 and MgO : Y2O3/CeO2 – ZrO2. Catalyst evaluation was performed in a fullscale reformer under real operating conditions. Results showed increased catalyst activity after the second monolithic catalyst due to the effect of steam reforming, WGS reaction, and higher catalyst reducibility of the RhxOy species in the CeO2 – ZrO2 mixed oxide, as a result of the improved redox properties. The influence of sulfur and coke formation on diesel reforming was assessed after 40 h on stream. Sulfur poisoning was evaluated for the intrinsic activity related to the total Rh and Pt area observed after exposure to sulfur. Sulfur concentration in the aged catalyst washcoat was observed to decrease in the axial direction of the reformer. Estimations of the amount of sulfur adsorbed were found to be below the theoretical equilibrated coverage on Rh and Pt, thus showing a partial deactivation due to sulfur poisoning. / <p>QC 20150213</p>
|
88 |
Internal Tar/CH4 Reforming in Biomass Dual Fluidised Bed Gasifiers towards Fuel SynthesisGöransson, Kristina January 2014 (has links)
Production of high-quality syngas from biomass gasification in a dual fluidised bed gasifier (DFBG) has made a significant progress in R&D and Technology demonstration. An S&M scale bio-automotive fuel plant close to the feedstock resources is preferable as biomass feedstock is widely sparse and has relatively low density, low heating value and high moisture content. This requires simple, reliable and cost-effective production of clean and good syngas. Indirect DFBGs, with steam as the gasification agent, produce a syngas of high content H2 and CO with 12-20 MJ/mn3 heating value. The Mid Sweden University (MIUN) gasifier, built for research on synthetic fuel production, is a dual fluidised bed gasifier. Reforming of tars and CH4 (except for methanation application) in the syngas is a major challenge for commercialization of biomass fluidised-bed gasification technology towards automotive fuel production. A good syngas from DFBGs can be obtained by optimised design and operation of the gasifier, by the use of active catalytic bed material and internal reforming. This thesis presents a series of experimental tests with different operation parameters, reforming of tar and CH4 with catalytic bed material and reforming of tar and CH4 with catalytic internal reformer. The first test was carried out to evaluate the optimal operation and performance of the MIUN gasifier. The test provides basic information for temperature control in the combustor and the gasifier by the bed material circulation rate. After proven operation and performance of the MIUN gasifier, an experimental study on in-bed material catalytic reforming of tar/CH4 is performed to evaluate the catalytic effects of the olivine and Fe-impregnated olivine (10%wtFe/olivine Catalyst) bed materials, with reference to non-catalytic silica sand operated in the mode of dual fluidised beds (DFB). A comparative experimental test is then carried out with the same operation condition and bed-materials but when the gasifier was operated in the mode of single bubbling fluidised bed (BFB). The behaviour of catalytic and non-catalytic bed materials differs when they are used in the DFB and the BFB. Fe/olivine and olivine in the BFB mode give lower tar and CH4 content together with higher H2+CO concentration, and higher H2/CO ratio, compared to DFB mode. It is hard to show a clear advantage of Fe/olivine over olivine regarding tar/CH4 catalytic reforming. In order to significantly reduce the tar/CH4 contents, an internal reformer, referred to as the FreeRef reformer, is developed for in-situ catalytic reforming of tar and CH4 using Ni-catalyst in an environment of good gas-solids contact at high temperature. A study on the internal reformer filled with and without Ni-catalytic pellets was carried out by evaluation of the syngas composition and tar/CH4 content. It can be concluded that the reformer with Ni-catalytic pellets clearly gives a higher H2 content together with lower CH4 and tar contents in the syngas than the reformer without Ni-catalytic pellets. The gravimetric tar content decreases from 25 g/m3 down to 5 g/m3 and the CH4 content from 11% down below 6% in the syngas. The MIUN gasifier has a unique design suitable for in-bed tar/CH4 catalytic reforming and continuously internal regeneration of the reactive bed material. The novel design in the MIUN gasifier increases the gasification efficiency, suppresses the tar generation and upgrades the syngas composition. / Gasification-based Biorefinery for Mechanical Pulp Mills
|
89 |
Conceptual design of gasification-based biorefineries using the C-H-O ternary diagramLitheko, Lefu Andrew 10 1900 (has links)
This dissertation develops a systematic targeting method based on the C-H-O ternary diagram for the conceptual design of gasification-based biorefineries. The approach is applied using dimethyl ether (DME) as case study. A stoichiometric equilibrium model is presented for calculation of the C-H-O chemical equilibria to evaluate and predict equilibrium syngas composition, operating temperature, type and amount of oxidant required in biomass gasification. Overall atomic species balances are developed and process targets are plotted on the C-H-O ternary diagram. Sustainability metrics are incorporated to provide useful insights into the efficiency of biorefinery process targets. It was found that syngas at 1200 and 1500 K is predominantly H2 and CO. Moreover, DME biorefineries have two main process targets, based on the indirect and direct synthesis routes. Gasification at 1200 K and 1 atm. using H2O/CO2 = 2.642 (w/w) and H2O/CH4 = 1.645 (w/w) achieved syngas composition targets for the direct and indirect methods respectively. Comparatively, the integrated biorefinery based on indirect route was more efficient, producing 1.903 ton of DME per ton of biomass feedstock. The process is 100% carbon-efficient and recycles 1.025 tons of H2O. / Civil and Chemical Engineering / M. Tech. (Chemical Engineering)
|
90 |
Reforma de gás de gaseificação por meio de tocha de plasma : ensaios preliminares / Reformation of gasification gas by plasma torch : preliminary resultsNeves, Renato Cruz, 1987- 23 August 2018 (has links)
Orientador: Caio Glauco Sánchez / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-23T14:06:22Z (GMT). No. of bitstreams: 1
Neves_RenatoCruz_M.pdf: 25784234 bytes, checksum: ce1b9833db6f80c61b19cd8781d17a52 (MD5)
Previous issue date: 2013 / Resumo: O desafio da tecnologia de reforma de gás de gaseificação é realizar a conversão de alcatrão e particulados em um gás, pois estes contaminantes podem trazer diversos problemas ao sistema de gaseificação como entupimento de filtros e corrosão. Dentre os equipamentos e métodos para a reforma do gás de gaseificação, encontra-se o plasma. Neste trabalho foi projetado, construído e ensaiado um sistema de reforma de gás de gaseificação proveniente de um reator de gaseificação utilizando a tocha de plasma. O sistema de reforma a plasma é constituído pela tocha de plasma inserida na garganta de um tubo convergente-divergente instalado na tubulação de saída do reator de gaseificação. A fonte de alimentação da tocha de plasma é o modelo Powermax1250 e a tocha é o modelo T80M, ambos da marca Hypertherm. A tocha de plasma utiliza nitrogênio como gás de trabalho, opera com pressão de 4; 0 bar no modo arco elétrico com corrente contínua, plasma térmico, não-transferido e alcança temperaturas superiores a 1673 K em distâncias menores que 30 mm. Na gaseificação foi utilizada a serragem de Peroba e Garapeira, fator de ar de 0; 22, velocidade de fluidização de 0,57 m.s-1 e utilizou-se 550 mm de altura do leito fixo de areia quartzosa. A coleta de alcatrão e particulado foi adaptada da norma CEN/BT/TF 143 ("Biomass gasification - Tar and particules in product gases - sampling and analysis"). Nas condições estudadas e analisadas deste trabalho, o valor obtido para a vazão mássica de alcatrão e material particulado foi de (5; 26+0; 58)10-3 g.s-1 para a gaseificação convencional enquanto que para a gaseificação utilizando a tecnologia da reforma de plasma foi de (3; 97+0; 14)10-3 g.s-1, que representou uma redução de 24; 52 % / Abstract: The technologic challenge on reformation of gasification gas is to convert tar and particulate matter into gas, because they can cause various problems on gasification system as corrosion and filters clogging. Among the equipment and methods for gasification gas reformation, it is used the plasma. In this work was designed, built and tested a system for gasification gas reformation from a gasification reactor using a plasma torch. The plasma system is formed by plasma torch inserted in the throat of a convergent-divergent tube installed in the outlet pipe of the gasification reactor. The power supply of the plasma torch is Powermax1250 and the model T80M plasma torch, both from Hypertherm brand. The plasma torch uses nitrogen as working gas, operates at a pressure of 4; 0 bar with arc current mode, thermal plasma, non-transferred and reaches temperatures above 1673 K in distances of less than 30 mm. In the gasification was used Peroba and Garapeira sawdust, air factor 0:22, fluidization velocity 0,57 m.s-1and 550 mm height fixed bed of quartz sand. The tar and particulate collection was adapted from CEN/BT/TF 143 (Biomass gasification - tar and particules in product gases - sampling and analysis). Under the conditions studied and analyzed in this work, the value obtained for the mass flow of tar and particulate material was (5; 26+0; 58)10-3 g.s-1 for conventional gasification while for using the reformation of gasification gas was de (3; 97+0; 14)10-3 g.s-1, which represented a reduction of 24:52 % / Mestrado / Termica e Fluidos / Mestre em Engenharia Mecânica
|
Page generated in 0.1077 seconds