scholarly journals Waste-to-Carbon: Is the Torrefied Sewage Sludge with High Ash Content a Better Fuel or Fertilizer?

Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 954 ◽  
Author(s):  
Jakub Pulka ◽  
Piotr Manczarski ◽  
Paweł Stępień ◽  
Marzena Styczyńska ◽  
Jacek A. Koziel ◽  
...  

Sewage sludge (SS) recycling is an important part of the proposed ‘circular economy’ concept. SS can be valorized via torrefaction (also known as ‘low-temperature pyrolysis’ or ‘roasting’). SS can, therefore, be considered a low-quality fuel or a source of nutrients essential for plant growth. Biochar produced by torrefaction of SS is a form of carbonized fuel or fertilizer. In this research, for the first time, we tested the feasibility of torrefaction of SS with high ash content for either fuel or organic fertilizer production. The research was conducted in 18 variants (six torrefaction temperatures between 200~300 °C, and three process residence times of 20, 40, 60 min) in 5 repetitions. Fuel and fertilizer properties and multiple regression analysis of produced biochar were conducted. The higher heating value (HHV) of raw SS was 21.2 MJ·kg−1. Produced biochar was characterized by HHV up to 12.85 MJ·kg−1 and lower H/C and O/C molar ratio. Therefore, torrefaction of SS with high ash content should not be considered as a method for improving the fuel properties. Instead, the production of fertilizer appears to be favorable. The torrefaction increased C, N, Mg, Ca, K, Na concentration in relation to raw SS. No significant (p < 0.05) influence of the increase of temperature and residence time on the increase of biogenic elements in biochar was found, however the highest biogenic element content, were found in biochar produced for 60 min, under the temperature ranging from 200 to 240 °C. Obtained biochars met the Polish regulatory criteria for mineral-organic fertilizer. Therefore SS torrefaction may be considered a feasible waste recycling technology. The calculation of torrefaction energy and the mass balance shows energy demand <2.5 GJ∙Mg−1 w.m., and the expected mass yield of the product, organic fertilizer, is ~178 kg∙Mg−1 w.m of SS. Further investigation should consider the scaling-up of the SS torrefaction process, with the application of other types of SSs.

2020 ◽  
Vol 99 (3) ◽  
pp. 259-264
Author(s):  
А.К. K. Маненко ◽  
Галина Михайловна Ткаченко ◽  
О.П. P. Касиян ◽  
С.Т. T. Юрченко

Introduction. Nowadays, in front of large cities, there is an acute problem for finding ways of environmentally safely dispose of accumulated sewage sludge and the possibility of its use. The most profitable way to utilize sewage sludge is to use them as organic fertilizers in agricultural production due to the high content of biogenic elements (nitrogen, phosphorus, potassium) and organic substances in their composition. However, the presence of heavy metals, pathogens, and other toxicants necessitates the study at the regional level the possibility of using these sediments as fertilizers. In each specific case, it is necessary to apply a scientific approach to the use of sewage sludge, since their composition is characterized by a qualitative and quantitative variation of chemical compounds. The purpose of the study was a hygienic justification for the possibility of using sludge for wastewater treatment from the municipal facilities in agricultural production as an organic fertilizer. Material and methods. The object of the study was sludge after treatment with flocculants and centrifugation and sludge stored on the sites of Lviv municipal facilities for 1, 6 and 18 months. In the experiment, the distribution of sludge components in the “plant-soil” dynamic system, as well as the degree of their accumulation in test plants, was determined. Quantitative determination of the of chemical elements content in samples of sludge and phytomass was carried out by atomic absorption spectrophotometry. Results. The effectiveness of the use of sludge from the municipal facilities for wastewater treatment in agricultural production as an organic fertilizer has been studied. It was found that the sludge dose of 50 tons/ha, using immediately after centrifuge, can not be used in the fields as a fertilizer. This dose caused a high phytotoxic effect on plants. The dose of used sludge (30 tons/ha after 1.5 years of maturing on silty areas) had a less pronounced phytotoxic effect, but the fact of fluorine, lead, cadmium, arsenic, mercury and manganese translocation from soil into the plants in high quantities was observed. This dose also cannot be used in the fields as a fertilizer. The use of a smaller dose should be justified by additional experiments.


Author(s):  
Mohammad Alizadeh Fard ◽  
Brian D. Barkdoll

Abstract Poor mixing in water storage tanks can cause stagnant zones that could pose negative public health effects. The present study uses Life Cycle Assessment to decide among the only three mixing options available, namely sprinkler, multiple inlets, and a mechanical mixer for the first time. These options were compared using different life cycle assessment (LCA) tools using an 80-year lifetime as the functional unit while assuming that all three options result in acceptable water quality. Using SimaPro modeling software as well as the IPCC 2013 GWP 100a V1.0 and Cumulative Energy Demand methods, these three mixing approaches were compared with and without waste recycling. Results showed that application of a sprinkler is the least expensive option. Damage-cost analyses for categories of human health, ecosystem quality, and resources showed that a sprinkler caused the least damage and cost, while a mixer resulted in the most damage and cost.


Processes ◽  
2019 ◽  
Vol 7 (9) ◽  
pp. 556 ◽  
Author(s):  
Marek Mysior ◽  
Maciej Tomaszewski ◽  
Paweł Stępień ◽  
Jacek A. Koziel ◽  
Andrzej Białowiec

A significant challenge in the utilization of alternative gaseous fuels is to use their energy potential at the desired location, considering economic feasibility and sustainability. A potential solution is a compression, transportation in pressure tanks, and generation of electricity and heat directly at the recipient. In this research, the potential for generating syngas from abundant waste substrates was analyzed. The sewage sludge (SS) was used as an example of a bulky and abundant resource that could be valorized via gasification, compression, and transport to end-users in containers. A model was developed, and theoretical analyses were completed to examine the influence of the calorific value of the syngas produced from the SS gasification (under different temperatures and gasifying agents) on the efficiency of energy transportation of compressed syngas. First, the gasification simulation was carried out, assuming equilibrium in a downdraft gasifier (reactor) from 973–1473 K and five gasifying agents (O2, H2, CO2, water vapor, and air). Molar ratios of the gasifying agents to the (SS) C ranged from 0.1–1.0. The model predicted syngas composition, lower calorific values (LHV) for a given molar ratio of the gasification agent, and compressibility factor. It was shown that the highest LHV was obtained at 0.1 molar ratio for all gasifier agents. The highest LHV (~20 MJ∙(Nm3)−1) was obtained by gasification with H2 and the lowest (~13 MJ∙(Nm3)−1) in the case of air. Next, the available syngas volume in a compressed gas transportation unit and the stored energy was estimated. The largest syngas volume can be transported when O2 is used as a gasifying agent, but the highest amount of transported energy was estimated for gasification with H2. Finally, the techno-economic analyses showed that syngas from SS could be competitive when the energy of compressed syngas is compared with the demand of an average residential dwelling. The developed syngas energy transport system (SETS) concept proposes a new method to distribute compressed syngas in pressure tanks to end-users using all modes of transport carrying intermodal ISO containers. Future work should include the determination of energy demand for syngas compression, including pressure losses, heat losses, and analysis of the influence of syngas on storage and compression devices.


2020 ◽  
Vol 99 (3) ◽  
pp. 259-264
Author(s):  
A. K. Manenko ◽  
Halyna M. Tkachenko ◽  
O. P. Kasiyan ◽  
S. T. Yurchenko

Introduction. Nowadays, in front of large cities, there is an acute problem for finding ways of environmentally safely dispose of accumulated sewage sludge and the possibility of its use. The most profitable way to utilize sewage sludge is to use them as organic fertilizers in agricultural production due to the high content of biogenic elements (nitrogen, phosphorus, potassium) and organic substances in their composition. However, the presence of heavy metals, pathogens, and other toxicants necessitates the study at the regional level the possibility of using these sediments as fertilizers. In each specific case, it is necessary to apply a scientific approach to the use of sewage sludge, since their composition is characterized by a qualitative and quantitative variation of chemical compounds. The purpose of the study was a hygienic justification for the possibility of using sludge for wastewater treatment from the municipal facilities in agricultural production as an organic fertilizer. Material and methods. The object of the study was sludge after treatment with flocculants and centrifugation and sludge stored on the sites of Lviv municipal facilities for 1, 6 and 18 months. In the experiment, the distribution of sludge components in the “plant-soil” dynamic system, as well as the degree of their accumulation in test plants, was determined. Quantitative determination of the of chemical elements content in samples of sludge and phytomass was carried out by atomic absorption spectrophotometry. Results. The effectiveness of the use of sludge from the municipal facilities for wastewater treatment in agricultural production as an organic fertilizer has been studied. It was found that the sludge dose of 50 tons/ha, using immediately after centrifuge, can not be used in the fields as a fertilizer. This dose caused a high phytotoxic effect on plants. The dose of used sludge (30 tons/ha after 1.5 years of maturing on silty areas) had a less pronounced phytotoxic effect, but the fact of fluorine, lead, cadmium, arsenic, mercury and manganese translocation from soil into the plants in high quantities was observed. This dose also cannot be used in the fields as a fertilizer. The use of a smaller dose should be justified by additional experiments.


Author(s):  
Kai Schumüller ◽  
Dirk Weichgrebe ◽  
Stephan Köster

AbstractTo tap the organic waste generated onboard cruise ships is a very promising approach to reduce their adverse impact on the maritime environment. Biogas produced by means of onboard anaerobic digestion offers a complementary energy source for ships’ operation. This report comprises a detailed presentation of the results gained from comprehensive investigations on the gas yield from onboard substrates such as food waste, sewage sludge and screening solids. Each person onboard generates a total average of about 9 kg of organic waste per day. The performed analyses of substrates and anaerobic digestion tests revealed an accumulated methane yield of around 159 L per person per day. The anaerobic co-digestion of sewage sludge and food waste (50:50 VS) emerged as particularly effective and led to an increased biogas yield by 24%, compared to the mono-fermentation. In the best case, onboard biogas production can provide an energetic output of 82 W/P, on average covering 3.3 to 4.1% of the total energy demand of a cruise ship.


2017 ◽  
pp. 356-362
Author(s):  
Lidiia Svirenko ◽  
Viktoriia Bondar

Ukraine is well-known in the world as a country with soil rich for humus. Approximately 68% of arable soils in Ukraine have been classificated as chernozem. For last decades decrease of organic matter content in soils of various agri-climatic zones has been surveyed in the country. The main reason of the mentioned process is enormous lack of organic fertilizer (manure) in agriculture connected with decrease in livestock (in 3 times since year 1992). Besides there is expansion of technical crops for biofuel production (like Brassica napus, Helianthus annuus), which are the provocateurs of soils exhaustion. At the same time such important source of organic matter for application in agriculture as sewage sludge (SS) from wastewater treatment plant (WWTP) is not used in Ukraine nowadays. To stop arable soils degradation in regions it is necessary to develop up-to-date management for fertilizer production on WWTPs. The base for the process has to be the acceptance of the goal-oriented National programme, corresponding governmental decrees and implementation of national standard for using sewage sludge as fertilizer.


2019 ◽  
Vol 85 (1II)) ◽  
pp. 73-76 ◽  
Author(s):  
V. I. Otmakhov ◽  
Yu. S. Sarkisov ◽  
A. N. Pavlova ◽  
A. V. Obukhova

150 years ago D. I. Mendeleev revealed the Periodic law to the world and since that time periodic dependencies have been increasingly used in various fields of basic and applied sciences. For the first time we consider the regularities of periodic dependences of the concentration of chemical elements in the ash residue of human hair on the number of the element. Such dependencies for various regions of Russia reveal strictly individual character. It is shown that distributions of the chemical elements for men and women also differ, as well as the distributions determined for the same groups in inhabitants of different regions of residence and depend to a significant extent on the genetic and physiological characteristics of human organism, variability of environmental conditions, earlier diseases and other impacts. This means that population of different urban regions (e.g., Siberian region) is characterized by a strictly individual distribution of biogenic elements. A hypothesis has been put forward that extrema observed on the studied dependences can be a kind of code for a given locality, reflecting correlation with various factors of genetic and ecological nature.


2018 ◽  
Vol 168 ◽  
pp. 08004
Author(s):  
Václav Peer ◽  
Jaroslav Frantík ◽  
Jan Kielar ◽  
Drahomír Mašek

Slow pyrolysis of solid materials can produce new materials usable for energy or chemical industry. The advantage of pyrolysis devices is the simple construction and process control and the ability to utilize materials with different properties (composition, ash content). Produced gaseous, liquid and solid materials could be used as a sources of energy, raw materials in chemical industry or substances for improving of soil properties. At article are described products of slow pyrolysis of biomass (wood chips), agrifuels (hay, wheat straw) and sewage sludge.


Author(s):  
Mahfud Mahfud ◽  
Ansori Ansori

Energy demand is currently increasing in line with technological and economic developments, but not accompanied by an increase in energy reserves. So we need another alternative energy that can be renewed, namely biodiesel. Biodiesel has been produced commercially through the transesterification from vegetable oil with methanol using catalyst that produces esters and glycerol. The formation of glycerol which is by-product can reduce its economic value, so it needs to be done the separation process. Therefore, a new route is proposed in this study, namely the interesterification reaction (non-alcoholic route) using methyl acetate as an alkyl group supplier and potassium methoxide catalyst. The superiority of the product produced by the interesterification reaction is biodiesel with triacetin byproducts which have an economical value and can be added to biodiesel formulations because of their solubility so that no side product separation process is needed. To increase the yield of biodiesel and the interesterification rate, the ultrasound method was used in this study. To optimize the factors that affect the interesterification reaction (molar ratio of methyl acetate to oil, catalyst concentration, temperature, and interesterification time), the Box-Behnken design (BBD) is used. Optimal operating conditions to produce the yields of biodiesel of 98.64 % are at molar ratio of methyl acetate to palm oil of 18.74, catalyst concentration of 1.24 %, temperature of 57.84 °C, and interesterification time of 12.69 minutes.


2010 ◽  
Vol 2 (5) ◽  
pp. 87-92
Author(s):  
Milda Radžiūtė ◽  
Audronė Matusevičiūtė

Sewage dump is the main organic waste component accumulating in water treatment companies, and therefore the utilization of dump remains a burning issue. Fertilization is the most popular and cheapest way of using sewage dump a part of which is intended for agriculture in most European countries for composting purposes. Sewage dump or its compost are suitable for fertilizing the upper layers of the soil in cases the concentration of heavy metals is not greater than sanitarian standards can tolerate. The examinations were carried out using different waste dump rates from Vilnius water treatment facility in willow (Salix viminalis) grown cultivated fields. The analysis of the soil was executed after one and two years following the fertilization process. The obtained results indicate that waste dump is a valuable organic fertilizer which contains small amounts of heavy metals. Separate heavy metals migrate from sewage sludge compost to plants differently. It was noted that the concentration of heavy metals in willows was greater (except for Pb and Cd) than that in the soil.


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