Environmental Technology Assessment of Natural Gas Compared to Biogas

h i g h l i g h t sAutumn was the best harvesting period of Laminaria sp. as feedstock for AD, in Ireland. During spring, the system was improved by applying the pretreatment and at a VS concentration of 2.5%. Higher methane yields were observed at short pretreatment times and at VS concentration below 2.5%. A positive energy balance was estimated in autumn and early spring. a b s t r a c tBrown seaweeds are a suitable substrate for biogas production through anaerobic digestion (AD). Since the carbohydrates' content is subjected to a seasonal variation, this research aimed to select the best harvesting period of beach cast brown seaweed Laminaria sp. for methane production, while optimising the use of a beating pretreatment and the organic substrate concentration. Response surface methodology (RSM) was used to estimate the effect of the beating pretreatment in terms of pretreatment time (5-10-15 min) and organic matter concentration in terms of volatile solids (VS) (1-2.5-4%) on methane production. The highest methane yield of 342 ± 17 ml g À1 VS was observed during November at 1% of VS and after 5 min of pretreatment, while the lowest yields were registered in March with an average of 163 ± 28 ml g À1 VS. However, an enhancement of 47% with respect to the untreated sample was achieved at 2.5% of VS and after 15 min of pretreatment, in March.

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“…A reference value of 9.67 kW h at 97% of methane was used [39,40], in order to calculate the energy content of the biogas produced.…”

Section: Energy Balance Calculation Methodsmentioning

confidence: 99%

Optimisation of biogas production from the macroalgae Laminaria sp. at different periods of harvesting in Ireland

et al. 2016

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“…It was produced from manure and kitchen waste and used as a fuel for gas cookers in China and India [1]. It consists of a mixture of gases, the major components being methane and carbon dioxide, but there are also other trace gases.…”

Section: Introductionmentioning

confidence: 99%

Pre-treatment techniques used for anaerobic digestion of algae

Rodríguez

Alaswad

Mooney

et al. 2015

Fuel Processing Technology

161

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“…Proving that the kiwi residue has adequate characteristics for the anaerobic digestion process, the energy recovery is of extreme interest. Based on the results from Eriksson [18], the volume of biogas generated in the process was converted into the corresponding volume of natural gas, taking into account the calorific value of methane (5.7 kWh.Nm -3 ). For this purpose, the highest biogas volume generated (assay 2.1) was used, which means a methane production of 928 L.kg Several authors have directed their research towards the recovery of waste either focused on energy production, or aiming at solving the environmental problems caused by wastes of different types and origins.…”

Section: Resultsmentioning

confidence: 99%

Anaerobic Digestion Performance in the Energy Recovery of Kiwi Residues

Martins

Boaventura

Paulista

2017

IOP Conf. Ser.: Earth Environ. Sci.

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Abstract. World production and trade of fruits generate losses in the harvest, post-harvest, handling, distribution and consumption phases, corresponding to 6.8% of total production. These residues present high potential as a substrate for the anaerobic digestion process and biogas generation. Thus, the energy valuation of the agro-industrial residues of kiwi production was evaluated by anaerobic digestion, aiming at optimizing the biogas production and its quality. Ten assays were carried out in a batch reactor (500 mL) under mesophilic conditions and varying a number of operational factors: different substrate/inoculum ratios; four distinct values for C: N ratio; inoculum from different digesters; and inoculum collected at different times of the year. The following parameters were used to control and monitor the process: pH, alkalinity, volatile fatty acids (VFA), volatile solids (VS) and chemical oxygen demand (COD). Among the tests performed, the best result obtained for the biogas production corresponded to the use of 2 g of substrate and 98 mL of inoculum of the anaerobic digester of the Wastewater Treatment Plant (WWTP) of Bragança, with addition of 150 mg of bicarbonate leading to a production of 1628 L biogas.kg -1 VS (57% methane). In relation to the biogas quality, the best result was obtained with 20 g of substrate and 380 mL of inoculum from the anaerobic digester sludge of WWTP of Ave (with addition 600 mg of sodium bicarbonate), presenting a value of 85% of CH 4 , with a production of 464 L biogas.kg -1 VS.

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Environmental Technology Assessment of Natural Gas Compared to Biogas

Cited by 23 publications

References 7 publications

Optimisation of biogas production from the macroalgae Laminaria sp. at different periods of harvesting in Ireland

Optimisation of biogas production from the macroalgae Laminaria sp. at different periods of harvesting in Ireland

Pre-treatment techniques used for anaerobic digestion of algae

Anaerobic Digestion Performance in the Energy Recovery of Kiwi Residues

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