Entity

Time filter

Source Type

Mexico City, Mexico

Escamilla-Alvarado C.,Environmental Biotechnology and Renewable Energies R and D Group | Poggi-Varaldo H.M.,Environmental Biotechnology and Renewable Energies R and D Group | Ponce-Noyola T.,Microbial Genetics Group | Rios-Leal E.,CINVESTAV | And 2 more authors.
International Journal of Hydrogen Energy | Year: 2015

A series of experiments were carried out aimed to evaluate the possibilities of integrating a stage for the saccharification of lignocellulosic substrates to a hydrogen, methane and enzymes producing biorefinery concept. Initially, three different substrates were saccharified using two sources of cellulases. The substrates were the organic fraction of municipal solid waste (OFMSW), fermented organic waste (FOW) produced after OFMSW fermentation in the hydrogen production stage, and filter paper bits. The enzymes evaluated were the enzyme extract obtained from Trichoderma reesei MCG 80 in our actual biorefinery process train and Celluclast® cellulases.All substrates were best hydrolyzed with the T. reesei extract. Saccharification efficiency on holocellulose basis of FOW was up to 73%, which represented 34% higher saccharification than OFMSW. Thereafter, the hydrolysis of FOW with the T. reesei extract was evaluated at different enzyme:substrate ratios in the range 40-120 filter paper units or FPUgVS-1. The lowest ratio of 40FPUgVS-1 presented the highest saccharification yield (11mgsugarsFPU-1). As an approach to further boost bioenergy production in the biorefinery, estimations of bioH2 production from FOW hydrolysates were performed, showing that the original hydrogen production from OFMSW (21LH2) could be doubled up to 43LH2 for each kilogram of dry OFMSW fed to the biorefinery.The H2 production in the H-M-Z-S inverse cascading biorefinery concept was found to be transcendental as it offers the possibilities of a renewable clean fuel and a pre-degraded substrate easily convertible into valuable bioproducts, or even into more biofuels. © 2015 Hydrogen Energy Publications, LLC. Source


Escamilla-Alvarado C.,Environmental Biotechnology and Renewable Energies RandD Group | Rios-Leal E.,CINVESTAV | Ponce-Noyola M.T.,Microbial Genetics Group | Poggi-Varaldo H.M.,Environmental Biotechnology and Renewable Energies RandD Group
Process Biochemistry | Year: 2012

The objective of this work was to evaluate the performance of a two-stage hydrogenogenic-methanogenic (H-M) semi-continuous process in terms of mass retention time (MRT) for hydrogenogenic stage (H-stage), feed source for methanogenic stage (M-stage) and thermal regime (35 and 55 °C) for both stages. The substrate was a model organic fraction of municipal solid wastes (OFMSW) at 35% total solids. In H-stage, mesophilic temperature had a positive significant effect on higher hydrogen productivities and lower amounts of hydrogen sinks compared to thermophilic operation. Calculations based on mass balances and biochemical stoichiometry confirmed that acid fermentation deviation was linked to low biohydrogen yields. The M-stage performance was influenced by both the temperature and feed source. Bioreactors in thermophilic regime performed better than mesophilic ones. Maximum methane productivity was 341 NmL CH4/(kgwmr d) that corresponded to the thermophilic bioreactor fed with fermented solids from H stage at 14 d MRT. The two-stage process showed higher gross energetic potential when compared to an only methanogenic process operated at equivalent MRT (control); this was due to a higher methane productivity in the M-stage of the series process. The main contribution of H-stage seemed to be associated to hydrolysis of the complex substrate thus generating metabolites for the M-stage rather than the hydrogen production itself. © 2012 Elsevier Ltd. All rights reserved. Source


Escamilla-Alvarado C.,Environmental Biotechnology and Renewable Energies RandD Group | Ponce-Noyola M.T.,Microbial Genetics Group | Poggi-Varaldo H.M.,Environmental Biotechnology and Renewable Energies RandD Group | Rios-Leal E.,CINVESTAV | And 2 more authors.
International Journal of Hydrogen Energy | Year: 2014

Biohydrogen production has been coupled in some cases to other energy production technologies in order to overcome its modest energy gains. Anaerobic digestion, when used for methane recovery, has long been regarded as an energy recovery technology. We determined the energy potential from the coupling of either semi-continuous or batch hydrogen lab-scale bioreactors to a methanogenic stage. All processes were performed in solid substrate fermentation mode using the organic fraction of municipal solid wastes as first fed. Semi-continuous reactors for hydrogen production, operated at 20.9% total solids, 21 d mass retention time and 55 °C, averaged 202 NmL H2/kgrwm/d. In the batch hydrogen stage at 20.9% total solids, 50 h fermentation time and 55 °C, the hydrogen yield was 1200 mmol H2/kgVS and initial hydrogenogenesis rate was 68.3 mmolH2/kgvs/h. The methanogenic stage in semi-continuous performance at 18.4% total solids, 28 d mass retention time and 55 °C produced 2023 NmL CH4/kgrwm/d. Resultant energetic potentials (ÊP) were calculated from the theoretical combustion of the total hydrogen or methane produced by all the substrate fed to the process. ÊP for semi-continuous and batch hydrogenogenesis were 256 and 271 kJ/kgdb, whereas for the methanogenic stage was 11,889 kJ/kgdb. Correspondingly, energetic fluxes (EF) were calculated from the theoretical combustion of the hydrogen or methane productivities. The EF for semi-continuous and batch hydrogenogenesis were 2.55 and 24.1 kJ/kgrwm/d, whereas for the methanogenic stage was 80.3 kJ/kgrwm/d. Indeed, coupling of the methanogenic stage to either semi-continuous or batch hydrogenogenesis increased their energetic potentials by 4600 and 4300%. These results showed the clear advantage of the methanogenesis coupling in order to yield high energetic potentials from wastes. © 2014 Hydrogen Energy Publications, LLC. Source


Escamilla-Alvarado C.,Environmental Biotechnology and Renewable Energies RandD Group | Poggi-Varaldo H.M.,Environmental Biotechnology and Renewable Energies RandD Group | Ponce-Noyola M.T.,Microbial Genetics Group
Waste Management and Research | Year: 2013

We evaluated the production of holocellulases from the cellulolytic microorganisms Cellulomonas flavigena PR-22 and Trichoderma reesei MCG 80 using as substrates the organic fraction of municipal solid waste (OFMSW) and digestates from a hydrogenogenic-methanogenic bioenergy production process. The first set of experiments (E1) used the mutant actinobacteria C. flavigena PR-22 whereas another set (E2) used the mutant filamentous fungi T. reesei MCG 80. In E1 with OFMSW as substrate, xylanolytic activities ranged from 1800 to 3900 international units gholocellulose -1 (IUg hol -1), whereas the cellulolytic activities ranged from 220 to 420 IUghol -1. The variation of agitation speed did not have a significant effect on enzyme activity, whereas the increase of substrate concentration had a significant negative effect on both xylanolytic and cellulolytic activities on a holocellulose feed basis. Regarding E2, the OFMSW was evaluated at 1, 2 and 3 % volatile solids (VS). At 2 % VS the best filter paper activities were 1200 filter paper units (FPU) l-1; however, in a holocellulase basis the best result was 67 FPU ghol -1 corresponding to 1 % VS. Next, OFMSW was compared with OFMSW supplemented with lactose, digested solids from hydrogenogenic fermentation (D1) and digested solids from a two-stage process (D2). Against expectations, no positive effect was found in OFMSW due to lactose. The best enzymatic titres were in the order D1 > OFMSW ≈ OFMSW + lactose > D2. The use of digestates from hydrogenogenic fermentation for enzyme production holds promise for waste management. It promotes energy and added-value bioproduct generation - a green alternative to common practice of management and disposal of organic wastes. © 2013 The Author(s). Source

Discover hidden collaborations