Microalgae Conversion to Biogas: Thermal Pretreatment Contribution on Net Energy Production

2014 ◽  
Vol 48 (12) ◽  
pp. 7171-7178 ◽  
Author(s):  
Fabiana Passos ◽  
Ivet Ferrer
Keyword(s):  
Energy Production ◽  
Net Energy ◽  
Thermal Pretreatment

scholarly journals Comparison of Different Electricity-Based Thermal Pretreatment Methods for Enhanced Bioenergy Production from Municipal Sludge

Molecules ◽  
2018 ◽  
Vol 23 (8) ◽  
pp. 2006 ◽  
Author(s):  
E. Hosseini Koupaie ◽  
T. Johnson ◽  
C. Eskicioglu
Keyword(s):  
Energy Production ◽  
Municipal Wastewater ◽  
Wastewater Sludge ◽  
Conventional Heating ◽  
P Value ◽  
Net Energy ◽  
Rf Heating ◽  
Thermal Pretreatment ◽  
Bioenergy Production ◽  
Sequential Pretreatment

This paper presents results for a comprehensive study that compares the performance of three electricity-based thermal pretreatment methods for improving the effectiveness of anaerobic digestion (AD) to process municipal wastewater sludge. The study compares thermal pretreatment using conventional heating (CH), microwave (MW), and radio frequency (RF) heating techniques. The effectiveness of the pretreatment methods was assessed in terms of chemical oxygen demand (COD) and biopolymers solubilization, AD bioenergy production, input electrical energy, and overall net energy production of the sequential pretreatment/AD process. The heating applicators for the bench-scale testing consisted of a custom-built pressure-sealed heating vessel for CH experiments, an off-the-shelf programmable MW oven operating at a frequency of 2.45 GHz for MW heating experiments, and a newly developed 1 kW RF heating system operating at a frequency of 13.56 MHz for RF heating experiments. Under identical thermal profiles, all three thermal pretreatment methods achieved similar sludge disintegration in terms of COD and biopolymer solubilization as well as AD bioenergy production (p-value > 0.05). According to the energy assessment results, the application of CH and MW pretreatments resulted in overall negative energy production, while positive net energy production was obtained through the sequential pretreatment/AD process utilizing RF pretreatment.

Using field data–based large eddy simulation to understand role of atmospheric stability on energy production of wind turbines

2019 ◽  
Vol 43 (6) ◽  
pp. 625-638 ◽  
Author(s):  
Jordan Nielson ◽  
Kiran Bhaganagar
Keyword(s):  
Large Eddy Simulation ◽  
Wind Turbines ◽  
Surface Heat Flux ◽  
Energy Production ◽  
Surface Flux ◽  
Surface Heat ◽  
Net Energy ◽  
Eddy Simulation ◽  
Large Eddy

A novel and a robust high-fidelity numerical methodology has been developed to realistically estimate the net energy production of full-scale horizontal axis wind turbines in a convective atmospheric boundary layer, for both isolated and multiple wind turbine arrays by accounting for the wake effects between them. Large eddy simulation has been used to understand the role of atmospheric stability in net energy production (annual energy production) of full-scale horizontal axis wind turbines placed in the convective atmospheric boundary layer. The simulations are performed during the convective conditions corresponding to the National Renewable Energy Laboratory field campaign of July 2015. A mathematical framework was developed to incorporate the field-based measurements as boundary conditions for the large eddy simulation by averaging the surface flux over multiple diurnal cycles. The objective of the study is to quantify the role of surface flux in the calculation of energy production for an isolated, two and three wind turbine configuration. The study compares the mean value, +1 standard deviation, and −1 standard deviation from the measured surface flux to demonstrate the role of surface heat flux. The uniqueness of the study is that power deficits from large eddy simulation were used to determine wake losses and obtain a net energy production that accounts for the wake losses. The frequency of stability events, from field measurements, is input into the calculation of an ensemble energy production prediction with wake losses for different wind turbine arrays. The increased surface heat flux increases the atmospheric turbulence into the wind turbines. Higher turbulence results in faster wake recovery by a factor of two. The faster wake recovery rates result in lowering the power deficits from 46% to 28% for the two-turbine array. The difference in net energy production between the +1 and −1 standard deviation (with respect to surface heat flux) simulations was 10% for the two-turbine array and 8% for the three-turbine array. An ensemble net energy production by accounting for the wake losses indicated the overestimation of annual energy production from current practices could be corrected by accounting for variation of surface flux from the mean value.

scholarly journals Re-assessment of net energy production and greenhouse gas emissions avoidance after 40 years of photovoltaics development

2016 ◽  
Vol 7 (1) ◽  
Author(s):  
Atse Louwen ◽  
Wilfried G. J. H. M. van Sark ◽  
André P. C. Faaij ◽  
Ruud E. I. Schropp
Keyword(s):  
Greenhouse Gas Emissions ◽  
Greenhouse Gas ◽  
Energy Production ◽  
Net Energy ◽  
Gas Emissions

scholarly journals Kesetimbangan Energi dan Manfaat dalam Aplikasi Produksi Bersih di Sistem Pengolahan Limbah Cair Industri Nanas Kaleng

2017 ◽  
Vol 14 (2) ◽  
pp. 75
Author(s):  
Pertiwi Andarani ◽  
Mega Mutiara Sari ◽  
Afni Siallagan
Keyword(s):  
Energy Production ◽  
Energy Ratio ◽  
Net Energy ◽  
Net Energy Ratio

Industri pengolahan buah umumnya memiliki kadar organik yang tinggi, Salah satunya adalah industri pengolahan nanas. PT Great Giant Pineapple, Lampung, (PT GGP) merupakan produsen nanas kaleng ekspor yang menghasilkan limbah yang berpotensi mencemari lingkungan apabila tidak dikelola dengan baik. Salah satu upaya pengelolaan lingkungan dan perbaikan berkelanjutan, PT GGP berupaya melaksanakan sistem produksi bersih. Produksi bersih merupakan suatu strategi pengelolaan lingkungan yang bersifat preventif dan terpadu yang perlu diterapkan secara terus menerus pada proses produksi dan daur hidup produk dengan tujuan megurangi resiko terhadap manusia dan lingkungan. Tujuan dari penelitian ini adalah untuk menganalisis kesetimbangan energi dan manfaat secara kuantitatif dalam penerapan sistem produksi bersih di sistem pengolahan limbah cair PT GGP. Kesetimbangan energi dianalisis dengan menggunakan indikator NER (Net Energy Ratio) dan NEP (Net Energy Production). Manfaat finansial dari penggunaan kembali sludge juga dievaluasi secara kuantitatif. Dalam produksi biogas jumlah energi input yang dibutuhkan sebesar 1,002 MJ/hari/m3 air limbah, menghasilkan jumlah energi output sebesar 108,587 MJ/hari/m3 air limbah. Sehingga Nilai NER = 108,37 dan NEP = 17,585 MJ/hari/m3 air limbah. Sementara itu, dengan pemanfaatan Sludge atas perusahaan memperoleh keuntungan sebesar Rp 3.326.687.65/hari dan pemanfaatan sludge bawah memperoleh keuntungan sebesar Rp 19.054.592 /hari pada tahun 2015.

An analysis of net energy production and feedstock availability for biobutanol and bioethanol

2011 ◽  
Vol 102 (2) ◽  
pp. 2112-2117 ◽  
Author(s):  
Jeffrey Swana ◽  
Ying Yang ◽  
Mohsen Behnam ◽  
Robert Thompson
Keyword(s):  
Energy Production ◽  
Net Energy ◽  
Feedstock Availability
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