Batch Mode Biomethane Production from Anaerobic Digestion of Palm Oil Mill Effluent (POME) with Cassava Peels and Cabbage Waste

Introduction: Biomedical waste (BMW) generated is a matter of great concern as it consists of high levels of hazardous waste. The lack of segregation and disposal policy in India leads to use of such infectious waste in day-to-day life [1]. Lack of awareness about segregation of Biomedical Waste (BMW) at source is a major cause for Hospital Acquired Infection (HAI) and increased risk of contamination of hospital and external environment. Materials & Methods: To address the problem, we decided to train interns and health care workers to increase their awareness about BMW segregation and thereby reduce HAI. The program was run in 3 phases. In the 1st phase need assessment was done as to how important and effective this program would be in controlling HAI. The 2nd phase comprised of identifying the stake holders in the program who will play the key role in implementing the program effectively. The 3rd phase of Biomedical Segregation Program BMWSP focused on the outcomes as enumerated in the Kirkpatrick model [2], viz., participants’ reaction, learning, change in behavior and results. Measuring the impact of the program on the learners at these four levels revealed the effectiveness of the program. Results: To overcome the shortfalls in the Kirkpatrick model we used Logic model which took care of the instructional design. Logic model is better suitable for evaluating BMWSP as it considers inter-relation between constituents in a sequence and their effect on the process as well as product providing the necessary roadmap from the planned work (inputs and activities) to the intended results (outputs, outcomes and impact). It is a sequence of events connecting each other starting with Resources / Inputs, Activities, Outputs, Outcomes and Impact. The model helped medical interns and dental students to understand the importance for BMWSP and also made a significant difference in its implementation. Conclusion: The program helped in making the health care staff more aware about BMWSP. It also increased their knowledge, and helped in implementation of the program. This will significantly reduce HAI and overall benefit the society.

Geographic Information Systems based approach for assessing the locational feasibility for biomethane production from landfill gas and injection in pipelines in Brazil / Abordagem baseada em sistemas de informação geográfica para avaliação da viabilidade locacional da produção de biometano a partir de gás de aterro sanitário e injeção em dutos no Brasil

ABSTRACT Biomethane can readily replace fossil fuels including natural gas, which has similar physical and chemical properties. In Brazil, municipal solid waste is predominantly disposed of in landfills. Landfill gas is mostly employed for electricity generation, but still at low levels when compared to the existing potential. Production of biomethane from landfill gas may be an alternative to exploit the existing potential, but Brazil's pipeline network is rather limited and concentrated along the country's coast. In this context, the research sought to identify the locational viability of using landfill gas to produce biomethane and injecting it into pipelines, considering the available potential and its proximity to Brazil's existing pipeline network. The QGis software was used to integrate the information. Territorial arrangements with a biomethane production capacity of more than 15,000 Nm3 day−1 and located up to 50 km from the pipeline network were considered feasible. The research estimated a potential production equivalent to 3,407,027 Nm3 day−1 of biomethane from landfills in Brazil. This potential corresponds to 6% of country's natural gas consumption in 2019 and is almost 32 times greater than current production of biomethane from all substrates used with this purpose in that year. The results indicate the suitability of using geographic information systems to identify regions that can benefit from the production of biomethane from landfill gas using the existing natural gas pipelines as an alternative to the electricity generation and provides relevant subsidies to the formulation of more efficient public policies in both the sanitation and energy sectors.

RESUMO O biometano pode substituir facilmente os combustíveis fósseis, incluindo o gás natural, que possui propriedades físicas e químicas similares. No Brasil, os resíduos sólidos urbanos são descartados predominantemente em aterros sanitários. O gás dos aterros sanitários é empregado principalmente na geração de eletricidade, mas ainda em níveis baixos quando comparado ao potencial existente. A produção de biometano a partir do gás de aterro pode ser uma alternativa para explorar o potencial existente, mas a rede de gasodutos do Brasil é bastante limitada e concentrada ao longo da costa do país. Nesse contexto, esta pesquisa buscou identificar a viabilidade locacional do uso de gás de aterro sanitário para produzir biometano e injetá-lo em dutos, considerando o potencial disponível e sua proximidade com a rede de dutos existente no Brasil. O software QGis foi utilizado para integrar as informações. Foram considerados viáveis arranjos territoriais com uma capacidade de produção de biometano maior que 15.000 Nm3 dia−1 e localizados a até 50 km da rede de gasodutos. A pesquisa estimou uma produção potencial equivalente a 3.407.027 Nm3 dia−1 de biometano a partir de aterros sanitários no Brasil. Esse potencial corresponde a 6% do consumo de gás natural do país em 2019 e é quase 32 vezes maior que a produção de biometano de todos os substratos utilizados com essa finalidade naquele ano. Os resultados indicam a adequação do uso de sistemas de informação geográfica para identificar regiões que podem se beneficiar da produção de biometano a partir de gás de aterro sanitário, utilizando os gasodutos de gás natural existentes como alternativa à geração de eletricidade e fornece subsídios relevantes para a formulação de políticas públicas mais eficientes, tanto no setor de saneamento quanto no de energia.

Evaluation of biogas and syngas as energy vectors for heat and power generation using lignocellulosic biomass as raw material

The use of nonrenewable energy sources to provide the worldwide energy needs has caused different problems such as global warming, water pollution, and smog production. In this sense, lignocellulosic biomass has been postulated as a renewable energy source able to produce energy carriers that can cover this energy demand. Biogas and syngas are two energy vectors that have been suggested to generate heat and power through their use in cogeneration systems. Therefore, the aim of this review is to develop a comparison between these energy vectors considering their main features based on literature reports. In addition, a techno-economic and energy assessment of the heat and power generation using these vectors as energy sources is performed. If lignocellulosic biomass is used as raw material, biogas is more commonly used for cogeneration purposes than syngas. However, syngas from biomass gasification has a great potential to be employed as a chemical platform in the production of value-added products. Moreover, the investment costs to generate heat and power from lignocellulosic materials using the anaerobic digestion technology are higher than those using the gasification technology. As a conclusion, it was evidenced that upgraded biogas has a higher potential to produce heat and power than syngas. Nevertheless, the implementation of both energy vectors into the energy market is important to cover the increasing worldwide energy demand.

Biohythane production from palm oil mill effluent – a preliminary evaluation of a two-stage anaerobic digestion

@#Aims:This research aims to investigate the potential of biohythane (biohydrogen and biomethane) production from palm oil mill effluent (POME) in a two-stage anaerobic digestion (AD) system.Methodology and results:A two-stage AD system was configured with a thermophilic dark fermenter (TDF) for biohydrogen (H2) production and a thermophilic anaerobic contact digester (TACD) for biomethane (CH4) production. To adjust pH 5.5 for dark fermentation, the settled sludge was recirculated from TACD to TDF. The hydraulic retention time (HRT) applied in TDF and TACD was 3.75 and 6.25 day, respectively.Conclusion, significance and impact of study:The sludge recirculation from TACD was able to adjust the pH in TDF to the optimum value of 5.5. The total COD and TSSdegradation were 63.12 and 77.94 %, respectively. The H2production in TDF was 1.54 L H2/L POME and the CH4production in TACD was 19.87 L CH4/L POME. The H2and CH4yielded 0.085 L/g CODremovedand 0.339 L/g CODremoved, respectively, with total energy recovery equivalent to 661.02 MJ/m3POME. Only 2.28 % of this energy was contributed by H2and the remaining was dominated by CH4.

Two phases fermentative process for hydrogen and methane production from cassava wastewater / Processo fermentativo em duas fases para a produção de hidrogênio e metano a partir da manipueira

Introduction: Hydrogen and methane production was investigated in two phases of fermentative process. Objective: At the acidogenic phase, an anaerobic fluidized bed reactor was fed with cassava wastewater producing hydrogen. Methods: Expanded clay was used as a support material for biomass immobilization. The reactor was operated with HRT ranging from 8-1 h. Results: The best hydrogen yield production was 1.91 mol H2/mol glucose at HRT of 2 h. At the methanogenic phase, the acidogenic process effluent fed a fixed-bed reactor producing methane. Conclusion: Sururu (Mytella falcata) shells was used as support acted as pH neutralizer in the fixed-bed reactor, yielding best (0.430±0.150 Lmethane/gCOD) with 12h HRT phase. (AU)

Introdução: A produção de hidrogênio e metano foi avaliada em um processo fermentativo de duas fases. Objetivo: Na fase acidogênica, um reator anaeróbio de leito fluidificado foi alimentado com manipueira para a produção de hidrogênio. Métodos: Argila expandida foi utilizada com material suporte para a adesão microbiana. O reator foi operado com TDH, variando entre 8-1h. Resultados: O melhor rendimento de produção de hidrogênio foi 1.91 mol, H2/mol glicose em TDH de 2 h. Na fase metanogênica, o efluente do processo acidogênico alimentou um reator de leito fixo para a produção de metano. Conclusão: Conchas de Sururo (Mytella falcata) foram utilizadas como suporte, atuando como neutralizador do pH no reator de leito fixo, melhor rendimento (0.430±0.150 Lmethane/gDQO) na fase com TDH de 12h. (AU)

Influence of manure concentration as inoculum in anaerobic digestion of vinasse / Influência da concentração de esterco como inóculo na digestão anaeróbia da vinhaça

Vinasse, main residue of the sugarcane industry, has high pollutant content, being subjected to the use in biogas production due to the high content of organic matter non-toxic to microbial action. For a consolidated process, it is necessary to study parameters that influence the process, in which the amount of inoculum is one of the major factors in the biological process of biogas production. This study investigated the influence of the amount of manure as inoculum (0.5 to 5.5%) during the biodigestion process, evaluating variables such as chemical oxygen demand (COD), pH, biogas production, methane concentration, total solids and total phosphorus and nitrogen contents, as well as microbiological analysis in the sludge remaining in the digester. Biodigestion occurred normally, with hydraulic retention time (HRT) of 20 days, with an acidogenic phase, subsequent stabilization of pH and biogas production. The vinasse had COD and total solids reduced during biodigestion by around 67 and 40%, respectively. Biogas production was increased after the fifth day. Among the three studied conditions, there was no significant increase in efficiency of inoculum use and it can be used the lowest amount, 0.5 % (m v-1).

A vinhaça, principal resíduo da indústria sucroalcooleira, possui alto teor poluente, sendo passível seu uso na produção de biogás devido ao grande teor de matéria orgânica não tóxica à ação microbiana. Para que haja um processo consolidado, é necessário estudar parâmetros que influem em seu processo, sendo a quantidade de inóculo um dos principais fatores no processo biológico de produção de biogás. Este estudo verificou a influência da quantidade de esterco bovino como inóculo (de 0,5 a 5,5%) durante o processo de biodigestão, avaliando variáveis como demanda química de oxigênio (DQO), pH, produção de biogás, concentração de metano, sólidos totais e teores de fósforo total e de nitrogênio total, além de análises microbiológicas no lodo restante no biodigestor. A biodigestão aconteceu normalmente, com um tempo de retenção hidráulica (TRH) de 20 dias, verificando-se a fase acidogênica, posterior estabilização do pH e produção de biogás. A vinhaça teve seus parâmetros de DQO e de sólidos totais diminuídos durante a biodigestão, em torno de 67 e 40%, respectivamente. Houve crescente produção de biogás após o quinto dia. Percebeu-se que, dentre as três condições estudadas, não houve significativa elevação da eficiência de uso de inóculo, podendo ser usada a menor quantidade, 0,5% (m v-1).

Co-digestión anaerobia de vinaza y gallinaza de jaula: alternativa para el manejo de residuos agrícolas colombianos / Anaerobic co-digestion of vinasse and chicken manure: alternative for Colombian agrowaste management

La digestión anaerobia es una tecnología atractiva para el manejo de residuos al producir energía en forma de biogás y estabilizar la materia orgánica. En este estudio, se evaluó el proceso de co-digestión de vinaza y gallinaza de jaula como una alternativa de manejo y estabilización de residuos generados por la agroindustria colombiana. Se llevaron a cabo, ensayos de biometanización en relaciones de mezcla vinaza y gallinaza de 1:0, 3:1, 1:3 y 0:1 en base a VS. La relación de 3:1 de vinaza y gallinaza permitió aumentar la producción específica de metano en un 55% respecto a la producción específica ponderada de 0.65 m³ CH4/kg VS. Las mezclas entre los sustratos presentaron un efecto sinérgico positivo. La gallinaza de jaula mejoró la capacidad de amortiguación de la mezcla, disminuyendo el riesgo de acidificación por cambio drástico en el pH durante la digestión de la vinaza. Por otra parte, la vinaza permitió diluir la concentración total de nitrógeno amoniacal evitando la inhibición de amoniaco. Dado el aumento de la producción de metano, el co-tratamiento de vinaza y gallinaza mejora la recuperación de energía y la viabilidad económica de la instalación de la planta de biogás como parte de la cadena de producción de etanol.

Anaerobic digestion is an attractive technology for waste management meanwhile energy is recovering. This study evaluated the feasibility of codigesting vinasse and chicken manure (CM) as management alternative for Colombian agro industries. Biochemical methane potential was tested for different vinasse to CM ratios of 1:0, 3:1, 1:3 and 0:1 on VS basis. Vinasse and CM ratio of 3:1 increased the specific methane production up to 55% regard to the weighted specific methane production of 0.65 m³CH4/kg VS. Mixtures between the substrates had a positive synergistic effect. CM improved buffer capacity diminishing the risk on acidification by drastic pH shift during vinasse digestion. Furthermore, vinasse allowed dilution of total ammonia nitrogen concentration avoiding ammonia inhibition. Since a higher methane production, vinasse and CM co-treatment improves the energy-recovery and economic feasibility of installing biogas plant as part of the ethanol production chain.