Anaerobic digestion of stillage fractions – estimation of the potential for energy recovery in bioethanol plants

2013 ◽  
Vol 67 (3) ◽  
pp. 494-505 ◽  
Author(s):  
B. Drosg ◽  
W. Fuchs ◽  
K. Meixner ◽  
R. Waltenberger ◽  
R. Kirchmayr ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Thermal Energy ◽  
Energy Demand ◽  
Energy Recovery ◽  
Animal Feed ◽  
Production Plant ◽  
Bioethanol Production ◽  
Thin Stillage ◽  
Recovery Potential ◽  
Whole Stillage

Stillage processing can require more than one third of the thermal energy demand of a dry-grind bioethanol production plant. Therefore, for every stillage fraction occurring in stillage processing the potential of energy recovery by anaerobic digestion (AD) was estimated. In the case of whole stillage up to 128% of the thermal energy demand in the process can be provided, so even an energetically self-sufficient bioethanol production process is possible. For wet cake the recovery potential of thermal energy is 57%, for thin stillage 41%, for syrup 40% and for the evaporation condensate 2.5%. Specific issues for establishing AD of stillage fractions are evaluated in detail; these are high nitrogen concentrations, digestate treatment and trace element supply. If animal feed is co-produced at the bioethanol plant and digestate fractions are to be reused as process water, a sufficient quality is necessary. Most interesting stillage fractions as substrates for AD are whole stillage, thin stillage and the evaporation condensate. For these fractions process details are presented.

Introducing a Novel Air Handling Unit Based on Focusing on Turbulent Exhaust Air Energy-Exergy Recovery Potential

2020 ◽  
Vol 142 (11) ◽  
Author(s):  
Yuanzhou Zheng ◽  
Rasool Kalbasi ◽  
Arash Karimipour ◽  
Peng Liu ◽  
Quang-Vu Bach
Keyword(s):  
Energy Consumption ◽  
Energy Demand ◽  
Energy Recovery ◽  
Primary Energy ◽  
Second Law ◽  
The Novel ◽  
Heating Coil ◽  
Recovery Potential ◽  
Air Handling Unit ◽  
Second Law Analysis

Abstract A novel air handling unit (AHU) aimed at reducing energy consumption was introduced in this study. In the proposed novel AHU, the heating coil is completely removed, and therefore, no heating coil energy demand is needed. The novel AHU used primary energy recovery as well as secondary one to utilize the return air energy and exergy. Through the first energy recovery unit, the return air exergy was recovered, while in the secondary heat exchanger, return air energy was recycled. Results showed that using the novel AHU leads to a reduction in energy consumption as well as the exergy losses. Three climate zones of A, B, and C were selected to assess the novel AHU performance. From the first law viewpoint, at zone B, using novel AHU has priority over other zones, while in the second law analysis, utilizing the novel AHU at zones B and C is more beneficial. Based on the first law analysis, owing to using novel AHU, energy consumption reduced up to 55.2% at Penang climate zone. Second law analysis revealed that utilizing the novel AHU decreased the irreversibility up to 51.4% in the Vancouver climate region.

scholarly journals The influence of crop dryer operation parameters on the efficiency of energy recovery from extract air

2019 ◽  
Vol 116 ◽  
pp. 00064
Author(s):  
Edward Przydróżny ◽  
Aleksandra Przydróżna ◽  
Sylwia Szczęśniak ◽  
Juliusz Walaszczyk
Keyword(s):  
Air Temperature ◽  
Thermal Energy ◽  
Energy Demand ◽  
Energy Recovery ◽  
Primary Energy ◽  
Specific Humidity ◽  
Primary Energy Demand ◽  
Air Temperatures ◽  
Flow Surface ◽  
Recovery System

Crop drying, especially maize drying, occurs at low external air temperatures, which are lower than the extract air temperature. Therefore, using heat exchangers, to recover thermal energy from the extract air to preheat the cold and dry external air, results in a significant reduction in the primary energy demand for crop drying. The measurements of air parameters in the crop dryer, with a drying capacity of 19 Mg/h of maize, confirm the assumptions undertaken for the production of the heat recovery system. We apply the cross-counter-flow surface heat exchanger system to provide a significant improvement in the efficiency of crop drying. We perform the analysis of the thermal energy recovery system operation. Our results indicate the influence of the drying air set-point and the crop specific humidity on the efficiency of energy recovery from the exhaust air. We performed our measurements at different drying air temperature set-points and different crop relative humidity.

Two-stage anaerobic digestion system treating different seasonal fruit pulp wastes: Impact on biogas and hydrogen production and total energy recovery potential

2020 ◽  
Vol 141 ◽  
pp. 105694
Author(s):  
Sara Mateus ◽  
Mónica Carvalheira ◽  
Joana Cassidy ◽  
Elisabete Freitas ◽  
Adrian Oehmen ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Hydrogen Production ◽  
Total Energy ◽  
Energy Recovery ◽  
Fruit Pulp ◽  
Two Stage ◽  
Recovery Potential

scholarly journals Methodological Approaches to Optimising Anaerobic Digestion of Water Hyacinth for Energy Efficiency in South Africa

2021 ◽  
Vol 13 (12) ◽  
pp. 6746
Author(s):  
Obianuju Patience Ilo ◽  
Mulala Danny Simatele ◽  
S’phumelele Lucky Nkomo ◽  
Ntandoyenkosi Malusi Mkhize ◽  
Nagendra Gopinath Prabhu
Keyword(s):  
South Africa ◽  
Anaerobic Digestion ◽  
Water Hyacinth ◽  
Energy Demand ◽  
Energy Recovery ◽  
Biogas Production ◽  
Meta Analysis ◽  
Operational Parameters ◽  
Invasive Alien Plants ◽  
Methodological Approaches

Anaerobic digestion has been identified as a feasible fragment of a bioeconomy, yet numerous factors hinder the adoption of the technology in South Africa. Apart from its energy recovery, other nonmarket advantages support the technology. Though it may be challenging to have a price tag, they provide clear added worth for such investments. With a growing energy demand and global energy transitions, there is a need to sustainably commercialise the biogas industry in South Africa. Most studies are at laboratory scale and under specific conditions, which invariably create gaps in using their data for commercialising the biogas technology. The key to recognising these gaps depends on knowing the crucial technical phases that have the utmost outcome on the economics of biogas production. This study is a meta-analysis of the optimisation of anaerobic digestion through methodological approaches aimed at enhancing the production of biogas. This review, therefore, argues that regulating the fundamental operational parameters, understanding the microbial community’s interactions, and modelling the anaerobic processes are vital indicators for improving the process stability and methane yield for the commercialisation of the technology. It further argues that South Africa can exploit water hyacinth as a substrate for a self-sufficient biogas production system in a bid to mitigate the invasive alien plants.

scholarly journals Distillery decarbonisation and anaerobic digestion: balancing benefits and drawbacks using a compromise programming approach

2021 ◽  
Vol 8 (3) ◽  
pp. 1417-1432
Author(s):  
Richard O’Shea ◽  
Richen Lin ◽  
David M. Wall ◽  
James D. Browne ◽  
Jerry D. Murphy
Keyword(s):  
Anaerobic Digestion ◽  
Animal Feed ◽  
Electricity Consumption ◽  
Compromise Programming ◽  
Programming Approach ◽  
Thin Stillage ◽  
Protein Loss ◽  
Food And Beverage ◽  
Criteria Weights ◽  
By Products

The anaerobic digestion (AD) of distillery by-products presents benefits such as greenhouse gas (GHG) emission savings and electricity savings, as well as drawbacks such as reduced animal feed and protein production and the potential import of animal feeds. This work balances these benefits and drawbacks using compromise programming (CP). The best combination of byproducts (from 9,261 scenarios) to use in AD was selected based on criteria chosen by management of a large distillery. The use of all by-products maximises benefits and drawbacks; the contrary also applies. When benefits and drawbacks are equally important, CP recommends using 50% of available draff, 50% of available thick stillage, and 55% of available thin stillage. The best combination when accounting for criteria weights chosen by distillery management is the use of 100% of available draff and 100% of available thick stillage. This could replace 48% of natural gas consumption at the distillery, reduce Scope 1 emissions by 45%, achieve a Scope 3 emissions savings of 22% of current Scope 1 emissions, and reduce electricity consumption in the feeds recovery plant of the distillery by 63%. Protein loss of 9,618 t could require the import of 19.59 kilo-tonne wet weight of material (ktwwt) of distillers grains and 9.15 ktwwt of soybean meal. If different criteria or criteria weights were used, a different result would be recommended. The methodology developed herein can aid in decarbonising the food and beverage industry by allowing decision-makers to balance the benefits and drawbacks of AD while accounting for subjective preferences.

scholarly journals Synergy of Thermochemical Treatment of Dried Distillers Grains with Solubles with Bioethanol Production for Increased Sustainability and Profitability

Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4528
Author(s):  
Samuel O’Brien ◽  
Jacek A. Koziel ◽  
Chumki Banik ◽  
Andrzej Białowiec
Keyword(s):  
Animal Feed ◽  
Value Added ◽  
Thermochemical Treatment ◽  
Calorific Value ◽  
Economic Feasibility ◽  
Production Plant ◽  
Fuel Quality ◽  
Bioethanol Production ◽  
Distillers Grains With Solubles ◽  
Heat Demand

The bioethanol industry continues improving sustainability, specifically focused on plant energy and GHG emission management. Dried distiller grains with solubles (DDGS) is a byproduct of ethanol fermentation and is used for animal feed. DDGS is a relatively low-value bulk product that decays, causes odor, and is challenging to manage. The aim of this research was to find an alternative, value-added-type concept for DDGS utilization. Specifically, we aimed to explore the techno-economic feasibility of torrefaction, i.e., a thermochemical treatment of DDGS requiring low energy input, less sophisticated equipment, and resulting in fuel-quality biochar. Therefore, we developed a research model that addresses both bioethanol production sustainability and profitability due to synergy with the torrefaction of DDGS and using produced biochar as marketable fuel for the plant. Our experiments showed that DDGS-based biochar (CSF—carbonized solid fuel) lower calorific value may reach up to 27 MJ∙kg−1 d.m. (dry matter) Specific research questions addressed were: What monetary profits and operational cost reductions could be expected from valorizing DDGS as a source of marketable biorenewable energy, which may be used for bioethanol production plant’s demand? What environmental and financial benefits could be expected from valorizing DDGS to biochar and its reuse for natural gas substitution? Modeling indicated that the valorized CSF could be produced and used as a source of energy for the bioethanol production plant. The use of heat generated from CSF incineration supplies the entire heat demand of the torrefaction unit and the heat demand of bioethanol production (15–30% of the mass of CSF and depending on the lower heating value (LHV) of the CSF produced). The excess of 70–85% of the CSF produced has the potential to be marketed for energetic, agricultural, and other applications. Preliminary results show the relationship between the reduction of the environmental footprint (~24% reduction in CO2 emissions) with the introduction of comprehensive on-site valorization of DDGS. The application of DDGS torrefaction and CSF recycling may be a source of the new, more valuable revenues and bring new perspectives to the bioethanol industry to be more sustainable and profitable, including during the COVID-19 pandemic and other shocks to market conditions.

scholarly journals Evaluation of Energy Recovery Potential by Anaerobic Digestion and Dark Fermentation of Residual Biomass in Colombia

2021 ◽  
Vol 9 ◽  
Author(s):  
Mónica Amado ◽  
Cristian Barca ◽  
Mario A. Hernández ◽  
Jean-Henry Ferrasse
Keyword(s):  
Anaerobic Digestion ◽  
Energy Recovery ◽  
Biogas Production ◽  
Operation Mode ◽  
Swine Manure ◽  
Dark Fermentation ◽  
Organic Load ◽  
Residual Biomass ◽  
Recovery Potential ◽  
Crucial Information

This study provides the first overview in Colombia on energy recovery potential by anaerobic digestion (AD) and dark fermentation (DF) of three different residual biomasses: coffee mucilage (CFM), cocoa mucilage (CCM), and swine manure (SM). First, AD and DF models were developed based on the ADM1 model. Then, simulated biogas production yields were compared to experimental data to validate the models. The results of comparative simulations indicate that energy recovery potentials from biogas for the different Colombian departments range from 148 to 48,990 toe, according to the local production amounts of CFM, CCM, and SM in 2017. The study provides crucial information that can be used to assess the best design, operation mode, and locations of AD and DF plants in Colombia. The results indicate that biogas production performances and energy recovery yields improve by increasing CFM/SM and/or CCM/SM ratios of the feed, and by increasing organic load from 2 to 26 gCOD∙l−1.

Influence of wastewater treatment on sludge production and processing

2015 ◽  
Vol 10 (1) ◽  
pp. 178-186 ◽  
Author(s):  
W. P. F. Barber
Keyword(s):  
Wastewater Treatment ◽  
Anaerobic Digestion ◽  
Thermal Energy ◽  
Energy Recovery ◽  
Energy Content ◽  
Primary Sludge ◽  
Secondary Sludge ◽  
Configuration Changes ◽  
Chemical Sludge ◽  
Sludge Production

The challenge of stricter wastewater standards is resulting in configuration changes to wastewater treatment. As facilities upgrade, the type of sludge produced is changing, with growing quantities of secondary and chemical sludge at the expense of primary sludge. It is already understood that secondary sludge is harder to treat than its primary equivalent; therefore, increasing the quantity of this type of sludge will have detrimental impacts downstream. As legislation tightens further, extended aeration times may be required during processing to remove more nutrients. Work has shown that extended aeration further exacerbates the difficulty of treating secondary sludge. This paper explains how tightening wastewater legislation fundamentally alters the nature of the sludge produced and how this affects further processing, especially with respect to sludge production and type; sludge energy content; performance of anaerobic digestion and dewatering, and potential for thermal energy recovery.

Sign in / Sign up

Export Citation Format

Share Document