The Experts below are selected from a list of 43641 Experts worldwide ranked by ideXlab platform
David Jeison - One of the best experts on this subject based on the ideXlab platform.
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a review on the state of the art of physical chemical and biological technologies for biogas upgrading
Reviews in Environmental Science and Bio\ technology, 2015Co-Authors: Leslie Meier, Israel Díaz, Raül Muñoz, David JeisonAbstract:The lack of tax incentives for biomethane use requires the optimization of both biogas production and upgrading in order to allow the full exploitation of this renewable energy source. The large number of biomethane contaminants present in biogas (CO2, H2S, H2O, N2, O2, methyl Siloxanes, halocarbons) has resulted in complex sequences of upgrading processes based on conventional physical/chemical technologies capable of providing CH4 purities of 88–98 % and H2S, halocarbons and methyl Siloxane removals >99 %. Unfortunately, the high consumption of energy and chemicals limits nowadays the environmental and economic sustainability of conventional biogas upgrading technologies. In this context, biotechnologies can offer a low cost and environmentally friendly alternative to physical/chemical biogas upgrading. Thus, biotechnologies such as H2-based chemoautrophic CO2 bioconversion to CH4, microalgae-based CO2 fixation, enzymatic CO2 dissolution, fermentative CO2 reduction and digestion with in situ CO2 desorption have consistently shown CO2 removals of 80–100 % and CH4 purities of 88–100 %, while allowing the conversion of CO2 into valuable bio-products and even a simultaneous H2S removal. Likewise, H2S removals >99 % are typically reported in aerobic and anoxic biotrickling filters, algal-bacterial photobioreactors and digesters under microaerophilic conditions. Even, methyl Siloxanes and halocarbons are potentially subject to aerobic and anaerobic biodegradation. However, despite these promising results, most biotechnologies still require further optimization and scale-up in order to compete with their physical/chemical counterparts. This review critically presents and discusses the state of the art of biogas upgrading technologies with special emphasis on biotechnologies for CO2, H2S, Siloxane and halocarbon removal.
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A review on the state-of-the-art of physical/chemical and biological technologies for biogas upgrading
Reviews in Environmental Science and Biotechnology, 2015Co-Authors: Raül Muñoz, Leslie Meier, Israel Díaz, David JeisonAbstract:The lack of tax incentives for biomethane use requires the optimization of both biogas production and upgrading in order to allow the full exploitation of this renewable energy source. The large number of biomethane contaminants present in biogas (CO2, H2S, H2O, N2, O2, methyl Siloxanes, halocarbons) has resulted in complex sequences of upgrading processes based on conventional physical/chemical technologies capable of providing CH4 purities of 88–98 % and H2S, halocarbons and methyl Siloxane removals >99 %. Unfortunately, the high consumption of energy and chemicals limits nowadays the environmental and economic sustainability of conventional biogas upgrading technologies. In this context, biotechnologies can offer a low cost and environmentally friendly alternative to physical/chemical biogas upgrading. Thus, biotechnologies such as H2-based chemoautrophic CO2 bioconversion to CH4, microalgae-based CO2 fixation, enzymatic CO2 dissolution, fermentative CO2 reduction and digestion with in situ CO2 desorption have consistently shown CO2 removals of 80–100 % and CH4 purities of 88–100 %, while allowing the conversion of CO2 into valuable bio-products and even a simultaneous H2S removal. Likewise, H2S removals >99 % are typically reported in aerobic and anoxic biotrickling filters, algal-bacterial photobioreactors and digesters under microaerophilic conditions. Even, methyl Siloxanes and halocarbons are potentially subject to aerobic and anaerobic biodegradation. However, despite these promising results, most biotechnologies still require further optimization and scale-up in order to compete with their physical/chemical counterparts. This review critically presents and discusses the state of the art of biogas upgrading technologies with special emphasis on biotechnologies for CO2, H2S, Siloxane and halocarbon removal.
Raül Muñoz - One of the best experts on this subject based on the ideXlab platform.
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a review on the state of the art of physical chemical and biological technologies for biogas upgrading
Reviews in Environmental Science and Bio\ technology, 2015Co-Authors: Leslie Meier, Israel Díaz, Raül Muñoz, David JeisonAbstract:The lack of tax incentives for biomethane use requires the optimization of both biogas production and upgrading in order to allow the full exploitation of this renewable energy source. The large number of biomethane contaminants present in biogas (CO2, H2S, H2O, N2, O2, methyl Siloxanes, halocarbons) has resulted in complex sequences of upgrading processes based on conventional physical/chemical technologies capable of providing CH4 purities of 88–98 % and H2S, halocarbons and methyl Siloxane removals >99 %. Unfortunately, the high consumption of energy and chemicals limits nowadays the environmental and economic sustainability of conventional biogas upgrading technologies. In this context, biotechnologies can offer a low cost and environmentally friendly alternative to physical/chemical biogas upgrading. Thus, biotechnologies such as H2-based chemoautrophic CO2 bioconversion to CH4, microalgae-based CO2 fixation, enzymatic CO2 dissolution, fermentative CO2 reduction and digestion with in situ CO2 desorption have consistently shown CO2 removals of 80–100 % and CH4 purities of 88–100 %, while allowing the conversion of CO2 into valuable bio-products and even a simultaneous H2S removal. Likewise, H2S removals >99 % are typically reported in aerobic and anoxic biotrickling filters, algal-bacterial photobioreactors and digesters under microaerophilic conditions. Even, methyl Siloxanes and halocarbons are potentially subject to aerobic and anaerobic biodegradation. However, despite these promising results, most biotechnologies still require further optimization and scale-up in order to compete with their physical/chemical counterparts. This review critically presents and discusses the state of the art of biogas upgrading technologies with special emphasis on biotechnologies for CO2, H2S, Siloxane and halocarbon removal.
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A review on the state-of-the-art of physical/chemical and biological technologies for biogas upgrading
Reviews in Environmental Science and Biotechnology, 2015Co-Authors: Raül Muñoz, Leslie Meier, Israel Díaz, David JeisonAbstract:The lack of tax incentives for biomethane use requires the optimization of both biogas production and upgrading in order to allow the full exploitation of this renewable energy source. The large number of biomethane contaminants present in biogas (CO2, H2S, H2O, N2, O2, methyl Siloxanes, halocarbons) has resulted in complex sequences of upgrading processes based on conventional physical/chemical technologies capable of providing CH4 purities of 88–98 % and H2S, halocarbons and methyl Siloxane removals >99 %. Unfortunately, the high consumption of energy and chemicals limits nowadays the environmental and economic sustainability of conventional biogas upgrading technologies. In this context, biotechnologies can offer a low cost and environmentally friendly alternative to physical/chemical biogas upgrading. Thus, biotechnologies such as H2-based chemoautrophic CO2 bioconversion to CH4, microalgae-based CO2 fixation, enzymatic CO2 dissolution, fermentative CO2 reduction and digestion with in situ CO2 desorption have consistently shown CO2 removals of 80–100 % and CH4 purities of 88–100 %, while allowing the conversion of CO2 into valuable bio-products and even a simultaneous H2S removal. Likewise, H2S removals >99 % are typically reported in aerobic and anoxic biotrickling filters, algal-bacterial photobioreactors and digesters under microaerophilic conditions. Even, methyl Siloxanes and halocarbons are potentially subject to aerobic and anaerobic biodegradation. However, despite these promising results, most biotechnologies still require further optimization and scale-up in order to compete with their physical/chemical counterparts. This review critically presents and discusses the state of the art of biogas upgrading technologies with special emphasis on biotechnologies for CO2, H2S, Siloxane and halocarbon removal.
Bart Van Meerbeek - One of the best experts on this subject based on the ideXlab platform.
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tem characterization of a silorane composite bonded to enamel dentin
Dental Materials, 2010Co-Authors: Atsushi Mine, Jan Munck, Annelies Van Ende, Marcio Vivan Cardoso, Takuo Kuboki, Yasuhiro Yoshida, Bart Van MeerbeekAbstract:Abstract Objectives The low-shrinking composite composed of combined Siloxane–oxirane technology (Filtek Silorane, 3M ESPE, Seefeld, Germany) required the development of a specific adhesive (Silorane System Adhesive, 3M ESPE), in particular because of the high hydrophobicity of the silorane composite. The purpose of this study was to characterize the interfacial ultra-structure at enamel and dentin using transmission electron microscopy (TEM). Methods Non-demineralized/demineralized 70–90 nm sections were prepared following common TEM specimen processing procedures. Results TEM revealed a typical twofold build-up of the adhesive resin, resulting in a total adhesive layer thickness of 10–20 μm. At bur-cut enamel, a tight interface without distinct dissolution of hydroxyapatite was observed. At bur-cut dentin, a relatively thin hybrid layer of maximum a few hundreds of nanometer was formed without clear surface demineralization. No clear resin tags were formed. At fractured dentin, the interaction appeared very superficial (100–200 nm). Distinct resin tags were formed due to the absence of smear plugs. Silver-nitrate infiltration showed a varying pattern of both spot- and cluster-like appearance of nano-leakage. Traces of Ag were typically detected along some part of the enamel–adhesive interface and/or between the two adhesive resin layers. Substantially more Ag-infiltration was observed along the dentin–adhesive interface of bur-cut dentin, as compared to that of fractured dentin. Conclusions The nano-interaction of Silorane System Adhesive should be attributed to its relatively high pH of 2.7. The obtained tight interface at both enamel and dentin indicates that the two-step self-etch adhesive effectively bridged the hydrophilic tooth substrate with the hydrophobic silorane composite.
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TEM Characterization of a Silorane Composite Bonded to Enamel/Dentin
Dental materials : official publication of the Academy of Dental Materials, 2010Co-Authors: Atsushi Mine, Jan Munck, Annelies Van Ende, Marcio Vivan Cardoso, Takuo Kuboki, Yasuhiro Yoshida, Bart Van MeerbeekAbstract:Abstract Objectives The low-shrinking composite composed of combined Siloxane–oxirane technology (Filtek Silorane, 3M ESPE, Seefeld, Germany) required the development of a specific adhesive (Silorane System Adhesive, 3M ESPE), in particular because of the high hydrophobicity of the silorane composite. The purpose of this study was to characterize the interfacial ultra-structure at enamel and dentin using transmission electron microscopy (TEM). Methods Non-demineralized/demineralized 70–90 nm sections were prepared following common TEM specimen processing procedures. Results TEM revealed a typical twofold build-up of the adhesive resin, resulting in a total adhesive layer thickness of 10–20 μm. At bur-cut enamel, a tight interface without distinct dissolution of hydroxyapatite was observed. At bur-cut dentin, a relatively thin hybrid layer of maximum a few hundreds of nanometer was formed without clear surface demineralization. No clear resin tags were formed. At fractured dentin, the interaction appeared very superficial (100–200 nm). Distinct resin tags were formed due to the absence of smear plugs. Silver-nitrate infiltration showed a varying pattern of both spot- and cluster-like appearance of nano-leakage. Traces of Ag were typically detected along some part of the enamel–adhesive interface and/or between the two adhesive resin layers. Substantially more Ag-infiltration was observed along the dentin–adhesive interface of bur-cut dentin, as compared to that of fractured dentin. Conclusions The nano-interaction of Silorane System Adhesive should be attributed to its relatively high pH of 2.7. The obtained tight interface at both enamel and dentin indicates that the two-step self-etch adhesive effectively bridged the hydrophilic tooth substrate with the hydrophobic silorane composite.
Thomas Melin - One of the best experts on this subject based on the ideXlab platform.
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suitability of tedlar gas sampling bags for Siloxane quantification in landfill gas
Talanta, 2010Co-Authors: Marc Ajhar, Bastian Wens, K H Stollenwerk, Gerd Spalding, Süleyman Yüce, Thomas MelinAbstract:Abstract Landfill or digester gas can contain man-made volatile methylSiloxanes (VMS), usually in the range of a few milligrams per normal cubic metre (Nm3). Until now, no standard method for Siloxane quantification exists and there is controversy with respect to which sampling procedure is most suitable. This paper presents an analytical and a sampling procedure for the quantification of common VMS in biogas via GC–MS and polyvinyl fluoride (Tedlar®) bags. Two commercially available Tedlar bag models are studied. One is equipped with a polypropylene valve with integrated septum, the other with a dual port fitting made from stainless steel. Siloxane recovery in landfill gas samples is investigated as a function of storage time, temperature, surface-to-volume ratio and background gas. Recovery was found to depend on the type of fitting employed. The Siloxanes sampled in the bag with the polypropylene valve show high and stable recovery, even after more than 30 days. Sufficiently low detection limits below 10 μg Nm−3 and good reproducibility can be achieved. The method is therefore well applicable to biogas, greatly facilitating sampling in comparison with other common techniques involving Siloxane enrichment using sorption media.
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Siloxane removal from landfill and digester gas a technology overview
Bioresource Technology, 2010Co-Authors: Marc Ajhar, Süleyman Yüce, M Travesset, Thomas MelinAbstract:This paper reviews technologies for the removal of volatile methyl Siloxanes (VMS) from biogas. More than 20 years after identifying silicon dioxide in gas engines running on landfill and sewage gas, three technologies are commercially available to remove Siloxanes today: adsorption, absorption and deep chilling. Newer concepts based on technologies other than sorption or condensation have not yet gained access to commercial biogas purification. These emerging Siloxane removal concepts include biotrickling filters, catalysts, membranes, and in the case of sewage gas, sludge stripping, peroxidation and filtration at point inlet source. This work introduces the main principles of commercial Siloxane removal systems and reviews scientific progress in the field over the last decade.
Atsushi Mine - One of the best experts on this subject based on the ideXlab platform.
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tem characterization of a silorane composite bonded to enamel dentin
Dental Materials, 2010Co-Authors: Atsushi Mine, Jan Munck, Annelies Van Ende, Marcio Vivan Cardoso, Takuo Kuboki, Yasuhiro Yoshida, Bart Van MeerbeekAbstract:Abstract Objectives The low-shrinking composite composed of combined Siloxane–oxirane technology (Filtek Silorane, 3M ESPE, Seefeld, Germany) required the development of a specific adhesive (Silorane System Adhesive, 3M ESPE), in particular because of the high hydrophobicity of the silorane composite. The purpose of this study was to characterize the interfacial ultra-structure at enamel and dentin using transmission electron microscopy (TEM). Methods Non-demineralized/demineralized 70–90 nm sections were prepared following common TEM specimen processing procedures. Results TEM revealed a typical twofold build-up of the adhesive resin, resulting in a total adhesive layer thickness of 10–20 μm. At bur-cut enamel, a tight interface without distinct dissolution of hydroxyapatite was observed. At bur-cut dentin, a relatively thin hybrid layer of maximum a few hundreds of nanometer was formed without clear surface demineralization. No clear resin tags were formed. At fractured dentin, the interaction appeared very superficial (100–200 nm). Distinct resin tags were formed due to the absence of smear plugs. Silver-nitrate infiltration showed a varying pattern of both spot- and cluster-like appearance of nano-leakage. Traces of Ag were typically detected along some part of the enamel–adhesive interface and/or between the two adhesive resin layers. Substantially more Ag-infiltration was observed along the dentin–adhesive interface of bur-cut dentin, as compared to that of fractured dentin. Conclusions The nano-interaction of Silorane System Adhesive should be attributed to its relatively high pH of 2.7. The obtained tight interface at both enamel and dentin indicates that the two-step self-etch adhesive effectively bridged the hydrophilic tooth substrate with the hydrophobic silorane composite.
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TEM Characterization of a Silorane Composite Bonded to Enamel/Dentin
Dental materials : official publication of the Academy of Dental Materials, 2010Co-Authors: Atsushi Mine, Jan Munck, Annelies Van Ende, Marcio Vivan Cardoso, Takuo Kuboki, Yasuhiro Yoshida, Bart Van MeerbeekAbstract:Abstract Objectives The low-shrinking composite composed of combined Siloxane–oxirane technology (Filtek Silorane, 3M ESPE, Seefeld, Germany) required the development of a specific adhesive (Silorane System Adhesive, 3M ESPE), in particular because of the high hydrophobicity of the silorane composite. The purpose of this study was to characterize the interfacial ultra-structure at enamel and dentin using transmission electron microscopy (TEM). Methods Non-demineralized/demineralized 70–90 nm sections were prepared following common TEM specimen processing procedures. Results TEM revealed a typical twofold build-up of the adhesive resin, resulting in a total adhesive layer thickness of 10–20 μm. At bur-cut enamel, a tight interface without distinct dissolution of hydroxyapatite was observed. At bur-cut dentin, a relatively thin hybrid layer of maximum a few hundreds of nanometer was formed without clear surface demineralization. No clear resin tags were formed. At fractured dentin, the interaction appeared very superficial (100–200 nm). Distinct resin tags were formed due to the absence of smear plugs. Silver-nitrate infiltration showed a varying pattern of both spot- and cluster-like appearance of nano-leakage. Traces of Ag were typically detected along some part of the enamel–adhesive interface and/or between the two adhesive resin layers. Substantially more Ag-infiltration was observed along the dentin–adhesive interface of bur-cut dentin, as compared to that of fractured dentin. Conclusions The nano-interaction of Silorane System Adhesive should be attributed to its relatively high pH of 2.7. The obtained tight interface at both enamel and dentin indicates that the two-step self-etch adhesive effectively bridged the hydrophilic tooth substrate with the hydrophobic silorane composite.
