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- A biorefinery approach for the simultaneous production of biofuels and bioplastics [Poster]Publication . Ortigueira, Joana; Leite, T.; Pereira, J.; Serafim, L.S.; Silva, Carla; Moura, Patrícia; Lemos, Paulo Costa
- Energy requirement and CO2 emissions of bioH2 production from microalgal biomassPublication . Ferreira, Ana F.; Ortigueira, Joana; Alves, Luís; Gouveia, Luisa; Moura, Patrícia; Silva, Carla M.This paper presents the life cycle inventory (LCI) of hydrogen production by Clostridium butyricum fermentation of Scenedesmus obliquus hydrolysate. The main purpose of this work was to evaluate the potential of H2 production from microalgal biomass and the respective energy consumption and CO2 emissions in the bioconversion process considering the microalga production, acid hydrolysis of S. obliquus biomass, preparation of the inoculum and culture media, and fermentation. The scale-up to industrial production was not envisaged. The hydrogen yield obtained in this work was 2.9 ± 0.3 mol H2/mol sugars in S. obliquus hydrolysate. Results show that this process of biological production of hydrogen can achieve 7270 MJ/MJH2 of energy consumption and 670Kg CO2/MJH2. The microalgal culture is the stage responsible for 98% of these total final values due to the use of artificial lighting. All stages and processes with the highest values of energy consumption and CO2 emissions were identified for future energetic and environmental optimisation.
- Admissibility Grid to Support the Decision for the Preferential Routing of Portuguese Endogenous Waste Biomass for the Production of Biogas, Advanced Biofuels, Electricity and HeatPublication . Crujeira, Teresa; Trancoso, Maria Ascensão; Eusebio, Ana; Oliveira, Ana Cristina; Passarinho, Paula; Abreu, Mariana; Marques, Isabel Paula; Marques, Paula; Marques, Susana; Albergaria, Helena; Pinto, Filomena; Costa, Paula; Andre, Rui N.; Girio, Francisco; Moura, PatríciaABSTRACT: A methodology was developed to assess the allocation of different types of endogenous waste biomass to eight technologies for producing electricity, heat, biogas and advanced biofuels. It was based on the identification of key physicochemical parameters for each conversion process and the definition of limit values for each parameter, applied to two different matrices of waste biomass. This enabled the creation of one Admissibility Grid with target values per type of waste biomass and conversion technology, applicable to a decision process in the routing to energy production. The construction of the grid was based on the evaluation of 24 types of waste biomass, corresponding to 48 sets of samples tested, for which a detailed physicochemical characterization and an admissibility assessment were made. The samples were collected from Municipal Solid Waste treatment facilities, sewage sludges, agro-industrial companies, poultry farms, and pulp and paper industries. The conversion technologies and energy products considered were (trans)esterification to fatty acid methyl esters, anaerobic digestion to methane, fermentation to bioethanol, dark fermentation to biohydrogen, combustion to electricity and heat, gasification to syngas, and pyrolysis and hydrothermal liquefaction to bio-oils. The validation of the Admissibility Grid was based on the determination of conversion rates and product yields over 23 case studies that were selected according to the best combinations of waste biomass type versus technological solution and energy product.
- Evaluation of the potential of biomass to energy in Portugal : conclusions from the CONVERTE projectPublication . Abreu, Mariana; Reis, Alberto; Moura, Patrícia; Fernando, Ana Luisa; Luís, Gabriel; Quental, Lídia; Patinha, Pedro; Gírio, FranciscoABSTRACT: The main objective of the Portuguese project "CONVERTE-Biomass Potential for Energy" is to support the transition to a low-carbon economy, identifying biomass typologies in mainland Portugal, namely agri-forest waste, energy crops and microalgae. Therefore, the aim was to design and construct a georeferenced (mapping) database for mainland Portugal, to identify land availability for the implementation of energy crops and microalgae cultures, and to locate agricultural and forestry production areas (including their residues) with potential for sustainable exploitation for energy. The ArcGIS software was used as a Geographic Information System (GIS) tool, introducing the data corresponding to the type of soil, water needs and edaphoclimatic conditions in shapefile and raster data type, to assess the areas for the implantation of the biomass of interest. After analysing the data of interest in each map in ArcGIS, the intersection of all maps is presented, suggesting adequate areas and predicting biomass productions for the implementation of each culture in mainland Portugal. Under the conditions of the study, cardoon (72 kha, 1085 kt), paulownia (81 kha, 26 kt) and microalgae (29 kha, 1616 kt) presented the greater viability to be exploited as biomass to energy in degraded and marginal soils.
- Hydrothermal processing of hardwoods and agro-industrial residues :evaluation of xylo-oligosaccharides productionPublication . Carvalheiro, Florbela; Fernandes, Talita Silva; Duarte, Luís C.; Lopes, Sónia; Moura, Patrícia; Pereira, Helena; Gírio, FranciscoAutohydrolysis was used as a pre-treatment method for the selective hydrolysis of hemicelluloses of four lignocellulosic materials: eucalypt wood chips (EWC), corn cobs (CC), wheat straw (WS) and brewery’s spent grain (BSG), and the process was optimized towards the production of xylo-oligosaccharides (XOS). The effects of temperature, both at isothermal (150-190ºC), and non-isothermal (up to 240ºC) conditions, and liquid-to-solid ratio (LSR), 8 or 10 g/g, on the composition of both the liquid and solid phases were studied. The operational conditions leading to the maximal recovery of XOS for each raw material were established and discussed based on the severity factor (log R0). The higher yields obtained were in the range of 43–65% of the feedstock (arabino)xylan, with the highest value attained for CC for log R0 =3.75. Under the optimised conditions for XOS production, glucan was only slightly solubilised, enabling an enrichment of the solid phase (up to 67% of glucan for EWC). Delignification was also not extensive reaching utmost 18%, in the case of CC. cosmetic industries.
- Diferenciação de isolados bacterianos com base no gene de Fe-hidrogenasesPublication . Pereira, Catarina; Nunes, J.; Rocha, Melissa; Moura, PatríciaO processo fermentativo de producao de H2 por microrganismos depende fundamentalmente da presenca de metaloenzimas designadas por hidrogenases. As hidrogenases sao enzimas envolvidas no metabolismo do H2, capazes de produzir ou consumir hidrogenio molecular, em processos relacionados com a transferencia de electroes e obtencao de energia. Elas catalisam a reaccao reversivel: H2 . 2H++ 2e- [1]. As hidrogenases dividem-se em classes filogeneticamente distintas, caracterizadas pelas diferentes subunidades ou dominios que acomodam o centro catalitico: as metalo-hidrogenases e as hidrogenases nao metalicas. As metalo-hidrogenases em particular podem ser divididas em dois tipos diferentes, conforme o conteudo metalico do seu centro catalitico: as que contem apenas ferro ([FeFe]-H2ases) e as que contem niquel e ferro ([NiFe]-H2ases), e que por vezes contem tambem selenio no seu centro catalitico ([NiFe(Se)]-H2ases) [2]. As [FeFe]-H2ases, existentes apenas em bacterias anaerobias e num pequeno numero de algas verdes, e em particular o gene hydA de [FeFe]-H2ases, que e o principal gene envolvido na producao de H2, sao considerados um biomarcador util para examinar a diversidade e distribuicao de microrganismos produtores de hidrogenio.
- Food waste biorefinery : stability of an acidogenic fermentation system with carbon dioxide sequestration and electricity generationPublication . Ortigueira, Joana; Pacheco, Marta; Trancoso, Maria Ascensão; Farrancha, Pedro; Correia, Jorge; Silva, Carla M.; Moura, PatríciaABSTRACT: The present study focused on the integration of the non-sterile conversion of food waste (FW) into hydrogen (H2) through dark fermentation with the subsequent electricity generation in a proton-exchange membrane fuel cell (PEMFC), and the assessment of the global warming potential (GWP) of the process. The acidogenic conversion of FW performed in continuous operation for 16 days produced 45.6 ± 0.1 L H2 at an average H2 productivity of 6.1 ± 1.3 L L−1 d−1. Butyric and acetic acid were simultaneously produced at average concentrations of 3.6 ± 0.5 and 1.6 ± 0.3 g L −1, respectively. The carbon dioxide (CO2) from biogas product was sequestered by reaction with sodium hydroxide and the resulting H2-rich stream was fed to a PEMFC, producing 1.7 Wh L−1 H2. The process scale-up was simulated based on the bench-scale conversion yields and was used to assess the GWP. Two of the developed scenarios, which considered the reuse of the fermentation sludge as nitrogen source in the acidogenic fermentation, diminished the GWP emissions by 63.8% and 64.3% when compared to the default condition. In the best-case scenario, an annual average of 0.18 t of CO2 per t of FW separately collected was generated.
- The production of pigments & hydrogen through a Spirogyra sp. biorefineryPublication . Pacheco, R.; Ferreira, Ana F.; Pinto, T.; Nobre, B. P.; Loureiro, David; Moura, Patrícia; Gouveia, Luisa; Silva, Carla M.This paper discusses the overall energy consumption and greenhouse gas emissions when extracting pigments and producing hydrogen from Spirogyra sp. microalga biomass. The energy evaluation from the biomass leftovers was also included in this work. The influence of the functional unit and different allocation criteria on the biorefinery assessments is also shown. The study consists of laboratory tests showing Spirogyra sp. growth, harvesting, drying, pigment extraction and fermentation by Clostridium butyricum. Electrocoagulation and solar drying were tested and compared to conventional centrifugation and electrical dewatering in terms of their energy consumption for harvesting and dewatering, respectively. To discuss the biorefinery viability, the pigments and biohydrogen (bioH2) retail costs are considered against operational costs according to electricity needs. The low yield of biochemical hydrogen and the high energy requirements for the pigment extraction were identified as main topics for further research. This research hopefully contributes to highlight the importance of energy and emission balances in order to decide on feasibility of the biorefinery.
- Energetic and environmental evaluation of microalgae biomass fermentation for biohydrogen productionPublication . Ferreira, Ana F.; Ortigueira, Joana; Alves, Luís; Gouveia, Luisa; Moura, Patrícia; Silva, Carla M.This paper presents an energetic and environmental evaluation of the fermentative hydrogen production from the sugars of Scenedesmus obliquus biomass hydrolysate by Clostridium butyricum. The main purpose of this work was to evaluate the potential of H2 production and respective energy consumptions and CO2 emissions in the global fermentation process: hydrolysis of S. obliquus biomass, preparation of the fermentation medium, degasification and incubation. The scale-up to industrial production was not envisaged. Energy consumption and CO2 emissions estimations were based on SimaPro 7.1 software for the preparation of the fermentation medium and the use of degasification gas, nitrogen. The functional unit of energy consumption and CO2 emissions was defined as MJ and grams per 1 MJ of H2 produced, respectively. The electricity consumed in all hydrogen processes was assumed to be generated from the Portuguese electricity production mix. The hydrogen yield obtained in this work was 2.9 ± 0.3 mol H2/mol sugars in S. obliquus hydrolysate. Results show that this process of biological production of hydrogen consumed 281-405 MJ/MJH2 of energy and emitted 24-29 kgCO2/ MJH2. The fermentation stages with the highest values of energy consumption and CO2 emissions were identified for future energetic and environmental process optimisation.
- Production, purification and characterisation of oligosaccharides from olive tree pruning autohydrolysisPublication . Cara, Cristóbal; Ruiz, Encarnación; Carvalheiro, Florbela; Moura, Patrícia; Ballesteros, Ignacio; Castro, Eulogio; Gírio, FranciscoThe production of oligosaccharides (OS) by olive tree pruning autohydrolysis in the range 170–230 °C was studied. The best results in terms of maximum yield of OS along with a low amount of byproducts were obtained at 180 °C. After purification by preparative gel filtration chromatography a range of OS-fractions with average degree of polymerisation (DP) from 25 to 3 was selected for further characterisation. Gluco-and xylooligosaccharides were the predominant OS in these fractions. OS yields in the range 80–90% were obtained for fractions with average DP between 25 and 7, practically free of low molecular compounds. Both OS total yields and xylooligosaccharides proportion decreased for lower DP fractions while monosaccharides and other products concentrations increased. OS production and the recovery of other high value compounds can be envisaged as an interesting contribution to develop an olive-biomass biorefinery.