scholarly journals Integration of Air Classification and Hydrothermal Carbonization to Enhance Energy Recovery of Corn Stover

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1397
Author(s):  
Md Tahmid Islam ◽  
Nepu Saha ◽  
Sergio Hernandez ◽  
Jordan Klinger ◽  
M. Toufiq Reza

Air classification (AC) is a cost-effective technology that separates the energy-dense light ash fraction (LAF) from the inorganic-rich high ash fraction (HAF) of corn stover. HAF could be upgraded into energy-dense solid fuel by hydrothermal carbonization (HTC). However, HTC is a high-temperature, high-pressure process, which requires additional energy to operate. In this study, three different scenarios (i.e., AC only, HTC only, and integrated AC–HTC) were investigated for the energy recovery of corn stover. AC was performed on corn stover at an 8 Hz fan speed, which yielded 84.4 wt. % LAF, 12.8 wt. % HAF, and 2.8 wt. % below screen particles. About 27 wt. % ash was reduced from LAF by the AC process. Furthermore, HTC was performed on raw corn stover and the HAF of corn stover at 200, 230, and 260 °C for 30 min. To evaluate energy recovery, solid products were characterized in terms of mass yield, ash yield, ultimate analysis, proximate analyses, and higher heating value (HHV). The results showed that the energy density was increased with the increase in HTC temperature, meanwhile the mass yield and ash yield were decreased with the increase in HTC temperature. Proximate analysis showed that fixed carbon increased 18 wt. % for original char and 27 wt. % for HAF char at 260 °C, compared to their respective feedstocks. Finally, the hydrochar resulting from HAF was mixed with LAF and pelletized at 180 bar and 90 °C to densify the energy content. An energy balance of the integrated AC–HTC process was performed, and the results shows that integrated AC with HTC performed at 230 °C resulted in an additional 800 MJ/ton of energy recovery compared to the AC-only scenario.

Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2984
Author(s):  
Anna Partridge ◽  
Ekaterina Sermyagina ◽  
Esa Vakkilainen

Upgrading biomass waste streams can improve economics in wood industries by adding value to the process. This work considers use of a hydrothermal carbonization (HTC) process for the residual feedstock after lignin and hemicelluloses extraction. Batch experiments were performed at 200–240 °C temperatures and three hours residence time with an 8:1 biomass to water ratio for two feedstocks: Raw spruce and spruce after lignin extraction. The proximate analysis and heating value showed similar results for both feedstocks, indicating that the thermochemical conversion is not impacted by the removal of lignin and hemicelluloses; the pretreatment processing slightly increases the heating value of the treated feedstock, but the HTC conversion process produces a consistent upgrading trend for both the treated and untreated feedstocks. The energy yield was 9.7 percentage points higher for the treated wood on average across the range temperatures due to the higher mass yield in the treated experiments. The energy densification ratio and the mass yield were strongly correlated with reaction temperature, while the energy yield was not. Lignocellulosic composition of the solid HTC product is mainly affected by HTC treatment, the effect of lignin extraction is negligible.


Recycling ◽  
2018 ◽  
Vol 3 (3) ◽  
pp. 46 ◽  
Author(s):  
Gabriele Fava ◽  
Tarun Naik ◽  
Mattia Pierpaoli

This study investigated the use of a biomass ash produced by a fuel combination made with wood, corn stover, and corn cob as cement replacement for the production of mortar. Biomasses are now widely accepted as a substitute for conventional fuels and are becoming essential for cost-effective production of energy. This study aimed to provide an opportunity for the annual agricultural corn-crop residue, corn stover and cob, which is increasingly being used as fuel for its valuable energy content. Measurements of workability, compressive strength, and leachate properties (pH, salinity, heavy metals and calcium ion release) of mortar specimen, at different cement substitution levels and ages, were evaluated. The results obtained reveal definitive possibilities for such mixed biomass ash to be used in cement-based materials, such as mortars. Moreover, a multiple regression analysis has been reported between the mass of calcium ions leached and the mixture composition with the compressive strength. Data show that further confirmation, on a longer span of time and of other types of mechanical properties and environmental tests, would be necessary to fully implement the use of such biomass ashes in various types of cement-based construction materials, in order to divert them from landfill disposal.


2019 ◽  
Vol 12 (1) ◽  
pp. 266 ◽  
Author(s):  
Andrea Capodaglio ◽  
Gustaf Olsson

Urban water systems and, in particular, wastewater treatment facilities are among the major energy consumers at municipal level worldwide. Estimates indicate that on average these facilities alone may require about 1% to 3% of the total electric energy output of a country, representing a significant fraction of municipal energy bills. Specific power consumption of state-of-the-art facilities should range between 20 and 45 kWh per population-equivalent served, per year, even though older plants may have even higher demands. This figure does not include wastewater conveyance (pumping) and residues post-processing. On the other hand, wastewater and its byproducts contain energy in different forms: chemical, thermal and potential. Until very recently, the only form of energy recovery from most facilities consisted of anaerobic post-digestion of process residuals (waste sludge), by which chemical energy methane is obtained as biogas, in amounts generally sufficient to cover about half of plant requirements. Implementation of new technologies may allow more efficient strategies of energy savings and recovery from sewage treatment. Besides wastewater valorization by exploitation of its chemical and thermal energy contents, closure of the wastewater cycle by recovery of the energy content of process residuals could allow significant additional energy recovery and increased greenhouse emissions abatement.


Water ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 899
Author(s):  
Djordje Mitrovic ◽  
Miguel Crespo Chacón ◽  
Aida Mérida García ◽  
Jorge García Morillo ◽  
Juan Antonio Rodríguez Diaz ◽  
...  

Studies have shown micro-hydropower (MHP) opportunities for energy recovery and CO2 reductions in the water sector. This paper conducts a large-scale assessment of this potential using a dataset amassed across six EU countries (Ireland, Northern Ireland, Scotland, Wales, Spain, and Portugal) for the drinking water, irrigation, and wastewater sectors. Extrapolating the collected data, the total annual MHP potential was estimated between 482.3 and 821.6 GWh, depending on the assumptions, divided among Ireland (15.5–32.2 GWh), Scotland (17.8–139.7 GWh), Northern Ireland (5.9–8.2 GWh), Wales (10.2–8.1 GWh), Spain (375.3–539.9 GWh), and Portugal (57.6–93.5 GWh) and distributed across the drinking water (43–67%), irrigation (51–30%), and wastewater (6–3%) sectors. The findings demonstrated reductions in energy consumption in water networks between 1.7 and 13.0%. Forty-five percent of the energy estimated from the analysed sites was associated with just 3% of their number, having a power output capacity >15 kW. This demonstrated that a significant proportion of energy could be exploited at a small number of sites, with a valuable contribution to net energy efficiency gains and CO2 emission reductions. This also demonstrates cost-effective, value-added, multi-country benefits to policy makers, establishing the case to incentivise MHP in water networks to help achieve the desired CO2 emissions reductions targets.


2016 ◽  
Vol 62 (No. 4) ◽  
pp. 179-184 ◽  
Author(s):  
J. Velebil ◽  
J. Malaťák ◽  
J. Bradna

In this article, the effect of increasing dry matter content and reaction time of hydrothermal carbonization on mass yield of biochar was studied. Carbonization took place in batch experiments in a pressure vessel. Results have confirmed the assumption that the mass yield of biochar would increase with growing dry matter content in the initial solution and also with reaction time at reaction temperature of 200°C. It was found that components of the liquid product that remain in the biochar have a measurable impact on its mass yield. Mixing of the reactor proved to have a considerable effect on the mass yield as well. Biochar produced in absence of mixing had higher pore volume and higher yield. This was evident even after subtracting the equivalent liquid phase dry matter in the biochar after drying.


2018 ◽  
Vol 77 (11) ◽  
pp. 2613-2623 ◽  
Author(s):  
Kerstin Schopf ◽  
Johannes Judex ◽  
Bernhard Schmid ◽  
Thomas Kienberger

Abstract A municipal wastewater treatment plant accounts for a large portion of the total energy consumption of a municipality. Besides their high energy demand, the plants also display a significant bioenergy potential. This is due to the utilisation of the energy content of digester gas and sewage sludge if there exist suitable units. To maximise the energy recovery efficiency of wastewater treatment systems (WWTS), it is important to analyse the amount of digester gas and sludge produced in different types of plants. Therefore, the present paper deals with designing a tool to answer the following research questions: Which bioenergy potentials occur in different plant types? Which mass and energy flows are related to the specific potentials? Which utilisation processes for the potentials can lead to a high energy recovery efficiency of WWTS? Preliminary analyses with the designed tool were focused on estimating the level of electric and thermal energy self-sufficiency of different plant configuration scenarios including or excluding digester gas and/or sludge utilisation units. First results based on the level of self-sufficiency and associated energy and disposal costs show that a digester gas and sewage sludge utilisation should be considered when designing future WWTS.


Author(s):  
Л. Евстратова ◽  
Г. Евсеева ◽  
С. Смирнов ◽  
А. Камова

В условиях Республики Карелия в 20152018 годах проведены трёхлетние научные исследования по определению оптимальных режимов скашивания и оценке их влияния на продуктивные и качественные характеристики бобовозлаковых травостоев с включением интродуцированных культур Medicago varia Mart. (сорт Таисия) и Festulolium F. Aschers.et Graebn. (сорт ВИК 90). Установлено, что в агроценозах массовая доля люцерны изменчивой при двуукосном режиме скашивания динамично возрастала с 4,029,1 до 34,442,2, а при трёхукосном с 3,927,6 до 48,860,3. Традиционный бобовый компонент Trifolium hybridum L. (сорт Первенец), наоборот, снизил своё участие в травостое с 22,451,4 до 1,315,3 и с 27,440,0 до 0,713,9 соответственно. Фестулолиум доминировал в травостое при трёхкратном скашивании в 1й и 2й годы пользования (56,1 и 69,5) и при двукратном во 2й и 3й годы (58,6 и 54,0). В среднем за 3 года как при двух, так и при трёхукосном режиме скашивания высокие показатели урожайности сухой массы (7,559,13 т/га), энергетической (6,2110,09 тыс. корм. ед./га 79,794,7 ГДж/га) и протеиновой (0,811,31 т/га) продуктивности обеспечили травостои: кострец безостый люцерна изменчивая клевер гибридный фестулолиум люцерна изменчивая клевер гибридный. Рассматриваемые значения превысили контроль (клеверозлаковый травостой) в 1,11,7 раза. Независимо от состава фитоценоза трёхкратное использование травостоев имело преимущество (на 18,661,7) только по сбору сырого протеина. В типичных погодных условиях полевого сезона лучшие результаты получены при двукратном режиме скашивания бобовозлаковых травостоев, а в экстремальных при трёхкратном. Последний обеспечил более равномерное распределение урожая зелёной массы по укосам и высокие показатели питательности корма. The investigations took place in the Republic of Karelia in 20152018. It was aimed to test cutting managements and their influence on grass productivity and quality and determine the optimal one. Legumegramineous ecosystems contained Medicago varia Mart. (variety Taisiya) and Festulolium F. Aschers.et Graebn. (variety VIK 90). The proportion of bastard alfalfa increased from 4.029.1 to 34.442.2 under two cuts, and from 3.927.6 to 48.860.3 under three cuts. The fraction of conventional grass component Trifolium hybridum L. (variety Pervenets) reduced from 22.451.4 to 1.315.3 and from 27.440.0 to 0.713.9, respectively. Festulolium prevailed in the 1st and 2nd years under three cuts (56.1 and 69.5) as well as in the 2nd and 3rd years under two cuts (58.6 and 54.0). Mixtures of smooth brome bastard alfalfa alsike clover festulolium bastard alfalfa alsike clover had the highest dry mass yield (7.559.13 t ha1), energy content (6.2110.09 thousand feed units ha1 79.794.7 GJ ha1) and protein concentration (0.811.31 t ha1). These values exceeded the ones of the control (clovergramineous mixture) by 1.11.7 times. Three cuts provided 18.661.7 more protein. Two cuts gave better results under typical regional climate, but three cuts were advantageous under unfavorable conditions.


Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 2058 ◽  
Author(s):  
Mateusz Jackowski ◽  
Lukasz Niedzwiecki ◽  
Magdalena Lech ◽  
Mateusz Wnukowski ◽  
Amit Arora ◽  
...  

Steady consumption of beer results in a steady output of residues, i.e., brewer’s spent grain (BSG). Its valorization, using hydrothermal carbonization (HTC) seems sensible. However, a significant knowledge gap regarding the variability of this residue and its influence on the valorization process and its potential use in biorefineries exists. This study attempted to fill this gap by characterization of BSG in conjunction with the main product (beer), taking into accounts details of the brewing process. Moreover, different methods to assess the performance of HTC were investigated. Overall, the differences in terms of the fuel properties of both types of spent grain were much less stark, in comparison to the differences between the respective beers. The use of HTC as a pretreatment of BSG for subsequent use as a biorefinery feedstock can be considered beneficial. HTC was helpful in uniformization and improvement of the fuel properties. A significant decrease in the oxygen content and O/C ratio and improved grindability was achieved. The Weber method proved to be feasible for HTC productivity assessment for commercial installations, giving satisfactory results for most of the cases, contrary to traditional ash tracer method, which resulted in significant overestimations of the mass yield.


Processes ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 444 ◽  
Author(s):  
Samuel Carrasco ◽  
Javier Silva ◽  
Ernesto Pino-Cortés ◽  
Jaime Gómez ◽  
Fidel Vallejo ◽  
...  

The effect of magnesium chloride as an additive of hydrothermal carbonization (HTC) of lignocellulosic biomass (Pinus radiata sawdust) was studied. The HTC tests were carried out at fixed conditions of temperature and residence time of 220 °C and 1 h, respectively, and varying the dose of magnesium chloride in the range 0.0–1.0 g MgCl2/g biomass. The carbonized product (hydrochar) was tested in order to determine its calorific value (HHV) while using PARR 6100 calorimeter, mass yield by gravimetry, elemental analysis using a LECO TruSpec elemental analyzer, volatile matter content, and ash content were obtained by standardized procedures using suitable ovens for it. The results show that using a dose of 0.75 g MgCl2/g biomass results in an impact on the mass yield that was almost equal to change operating conditions from 220 to 270 °C and from 0.5 to 1 h, without additive. Likewise, the calorific value increases by 33% for this additive dose, resulting in an energy yield of 68%, thus generating a solid fuel of prominent characteristics.


2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 735-735
Author(s):  
Oyetunji Akinola

Abstract Objectives The main shelf-stable product of yam is the traditional yam flour (elubo), Yams (Dioscorea spp.) which are regarded as traditional foods are consumed in various ways but majorly consumed as yam flour in the south west region of Nigeria. This study investigated the physical, functional and sensory properties and anti-nutrients contents of peeled and unpeeled yam flour. Methods Yam bought in the popular market production procedures were followed, washing, peeling and slicing, parboiling, steeping. draining, drying, milling, and packaging for peeled yam and unpeeled yam peeling was not included in the process, the two samples were analyzed chemically according to the official methods of analysis described by the Association of Official Analytical Chemist as well as sensory evaluation. Results The results of the study confirmed the significant difference in the micro nutrients content of peeled and unpeeled yam flour in fats and water soluble vitamins respectively (K µg/100 g = 6.97,11.83, Fe(mg/kg) = 95.2, 126.9, minerals content Zn(mg/kg) 13.48, 22.92, Fe(mg/kg) 95.2126.9 and anti-nutrient properties of the ‘Amala’ made from the two products (peeled and unpeeled yam flour) the percentage of Tannin 0.0023, 0.0010 and Hydrocynaide (mg/kg) 0.92, 1.01.The proximate analysis of unpeeled yam four indicated a high value than that of peeled yam flour in protein (2.47, 2.28), fats (1.86, 0.54), ash (3.59, 2.32), and fibre (3.09, 1.31) of both samples respectively but the energy content derived from the ‘amala’ made from unpeeled yam flour is lesser to that of peeled yam flour. Significant exist between the two samples in sensory evaluation of taste, texture, color, mouldability, aroma and general acceptability. Conclusions The result shown that the consumption of unpeeled yam flour can be useful in treatment of nutrient deficiencies diseases. Funding Sources Self.


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