Next Article in Journal
Comparative Transcriptome Analysis Reveals Common and Developmental Stage-Specific Genes That Respond to Low Nitrogen in Maize Leaves
Next Article in Special Issue
Polysaccharides from South Tunisian Moringa alterniflora Leaves: Characterization, Cytotoxicity, Antioxidant Activity, and Laser Burn Wound Healing in Rats
Previous Article in Journal
Ecophysiological Responses of Tall Wheatgrass Germplasm to Drought and Salinity
 
 
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Article

Feasibility of Old Bark and Wood Waste Recycling

1
Institute of Living Systems, Immanuel Kant BFU, 236016 Kaliningrad, Russia
2
Environmental Protection Department, Perm National Research Polytechnic University, 614000 Perm, Russia
3
Department of Inorganic Chemistry, Chemical Technology and Technosphere Safety, Perm State National Research University, St. Bukireva, 15, 614990 Perm, Russia
*
Author to whom correspondence should be addressed.
Plants 2022, 11(12), 1549; https://doi.org/10.3390/plants11121549
Submission received: 18 May 2022 / Revised: 3 June 2022 / Accepted: 7 June 2022 / Published: 10 June 2022
(This article belongs to the Special Issue Bioprospection and Sustainable Use of Plants)

Abstract

:
The pulp and paper industry leads to the formation of significant amounts of bark and wood waste (BWW), which is mostly dumped, causing negative climate and environmental impacts. This article presents an overview of methods for recycling BWW, as well as the results of assessing the resource potential of old bark waste based on physicochemical and thermal analysis. It was found that using BWW as a plant-growing substrate is challenging because it was observed that bark waste is phytotoxic. The C:N waste ratio is far from optimum; moreover, it has a low biodegradation rate (less than 0.15% per year). The calorific value content of BWW ranged from 7.7 to 18.9 MJ/kg on d.m., the ash content was from 4% to 22%, and the initial moisture content was from 60.8% to 74.9%, which allowed us to draw conclusions about the feasibility of using hydrothermal methods for their processing to obtain biofuel and for the unreasonableness of using traditional thermal methods (combustion, pyrolysis, gasification).

Graphical Abstract

1. Introduction

The Russian Federation is ranked second in the world for wood reserves and sixth for wood processing [1]. The problem of effective and integrated use of wood waste is becoming increasingly urgent as the volume of its processing increases. The pulp and paper industry waste, primarily BWW and dehydrated cellulose sludge, contributes significantly to the composition of wood waste [2].
The volume of BWW generation in Russia is approximately 2 million tons [3], with only 2% being processed [4]. In comparison, the United States pulp and paper industry recycles approximately 20 million tons or 25% of BWW per year [5,6].
BWW is not considered to be a waste in countries with well-developed forestry, such as Finland, Sweden, Germany, Canada, and the United States, but rather as a raw resource from which valuable products can be obtained. This approach not only reduces the cost of production, but also brings additional profit to the pulp and paper industry [7]. BWW is already widely used in bioenergy in developed countries [8,9,10]. China is also on the bioenergy path, with plans to produce 50 million tons of fuel pellets per year by 2025 [11,12].
Russia is now in the process of stimulating BWW processing and recycling. Therefore, one of the goals of the Russian Federation program “Development of industry and increasing its competitiveness” is to develop the production of bioenergy and biofuels and increase the processing of low-grade wood and bark waste [13]. However, only a small amount of wood debarking waste is currently used for incineration and agricultural purposes in Russia [4], with the majority of waste being disposed of in landfills.
Many bark dumps today contain tens of millions of cubic meters of BWW, which is rarely used for commercial or energy production but causes extensive environmental damage. An ecological threat is posed by the acidity of the soil and contamination of water bodies with extracts and products of bark decay; moreover, BWW forms large amounts of greenhouse gases, and the dumps are highly inflammable during arid periods [3,13].
Natural biodegradation in real conditions occurs much more slowly than previously thought, particularly in flooded layers [13,14,15,16]. It was shown that even after more than 80 years of storage, complete humification of wood in the body of bark dump does not occur (wood chips and bark particles completely retained their structure in samples of 75–82 years storage). The preceding highlights the importance of creating solutions for the safe disposal and use of BWW, particularly those that have been stored for a long period [17].
Summarizing global experience, various options for using BWW from the pulp and paper industry are currently available, which can be classified into three categories: chemical, biological, and thermal.
The main chemical processing methods for BWW are extraction and hydrolysis. Organic solvents (hexane, isopropanol) and water are used as extractants [18]. The hydrolysis of BWW in the presence of catalysts (acid salts, mineral acids) produces a variety of food, feed, and industrial products (alcohol, yeast, carbon dioxide) [19]. The scientific literature lacks information on the experience of the use and proven effectiveness of chemical methods in relation to long-stored bark.
The biological method of BWW processing is the most widely used, especially for long-term storage waste. It is based on anaerobic digestion and composting processes [3,20,21,22]. Composting can be carried out both in the field and in various types of bioreactors (bio-drums, biotunnels, etc.) in order to produce fertilizers and ameliorants [23]. Preparing BWW for biodegradation involves preliminary grinding and the addition of various additives, depending on the intended type of target product. BWW is pre-treated with urea, calcium carbonate, phosphate, and zeolite to concentrate nitrogen and phosphorus, and the resulting material is placed in compost heaps. Lime or ash can be added to the compost to adjust the pH of the final product [3,24,25,26,27].
Products can be used for intermediate waste isolation on landfills, reclamation of disturbed lands, landscaping, or as fertilizer to improve the topsoil structure and to stimulate the growth of plants [2,3,28,29,30].
Biotechnological approaches to the pulp and paper industry’s waste management, based on biocatalytic and biotransformation processes, are currently in demand [4]. Micromycete fungi that produce extracellular enzymes, various plant metabolites, biopolymers (cellulose, hemicellulose, lignin, humus) [31,32], and xenobiotics [33] are the cultures suitable for processing pulp and paper industry waste components. Various bacterial cultures, including biodestructors of plant components, and such worm cultures such as Eisenia fetida, Eisenia andrei, Eudrilus eugeniae, Perionyx excavates, and Perionyx sansibaricus [24,25] can also be used. The product of vermicomposting, or biohumus, obtained from organic waste, undergoes physicochemical, biological, and microbiological transformations in the intestines of worms to obtain a granular structure [3,25,34]. However, these technologies are still under development and have not been widely used.
Thermal methods are represented by combustion, pyrolysis and gasification, and hydrothermal methods [35,36,37,38]. Thermal or electrical energy is the primary product of BWW combustion; ash (10–20% by mass) is formed as a waste [39]. The pyrolysis process generates thermal energy, but in the case of BWW processing, it is typically fully utilized to support the process. Charcoal is a byproduct of the pyrolysis process that can be used commercially as a sorption material, biofertilizer, and for greenhouse gas sequestration [39,40,41,42,43]. Dry gasification of BWW is used to generate heat and electricity, as well as for the synthesis of gas [40]. The problem with all traditional thermal processing methods is that they are difficult to apply to the processing of BWW previously accumulated in the bark dump, because the waste is characterized by high humidity (up to 60%) [14,44].
Hydrothermal methods, which ensure the processing of wet biomass without pre-drying, are a promising branch of thermal methods for BWW processing. Hydrothermal carbonization (HTC) is the process of converting cellulosic low-calorie biomass (with humidity up to 80%) at temperatures of 250–300 °C and at pressures of 2–20 MPa into hydrochar [32,45,46]. The yield is 62–78% of dry biomass, which can be further used to generate heat as a carbon source [47]. Temperature (optimally not less than 250 °C), water:substrate ratio (optimally no more than 1:4) [48], and pH (optimally no higher than 3) all affect the efficiency of the process [14,48]. The typical time of the HTC process is from 1 to 72 h [49].
Hydrothermal liquefaction (HTL) is a wet-biomass processing method that produces liquid synthetic oil [18,35,44]. The process is designed to treat pulp with a maximum dry matter concentration of 20% [50]. The efficiency of the process is largely affected by the pH value; thus, with a decrease in pH, the yield of char increases significantly, and the yield of liquid fuel decreases [44,51]. The yield of synthetic oil for various types of wood is 10–30% [52,53,54]. For example, the organic components of HTL-oil derived from BWW have an average molecular weight of 310–470 g/mol [55] and are mainly represented by carboxylic acids, furfurals, ketones, aromatic, saturated and unsaturated hydrocarbons. HTL-oil is viscous and, unlike pyrolysis oil, has a low oxygen content and a higher calorific value [36]. The gas and water phases, as well as HTL-char [44], are the byproducts of the HTL process.
Hydrothermal gasification of BWW is carried out at a temperature of about 350 °C and a pressure of 20 MPa, resulting in the formation of a methane-rich gas [40]. The ideal conditions for hydrothermal gasification include a biomass dry matter concentration of less than 10% [40], a high heating rate, the addition of alkali salts (K2CO3, KHCO3, etc.) to prevent coke formation [56], and temperatures of 400–550 °C [57,58]. There is experience in implementing processes at lower temperatures (270–450 °C) in the presence of homogeneous and heterogeneous catalysts [51,59].
The general advantage of hydrothermal methods is their applicability to wet biomass, because water does not interfere with the process, but participates by acting as a donor of hydrogen ions and, in some cases, as a polar solvent [44]. Although HTC is the simplest and most easily implemented method, the resulting hydrochar is not widely sold. More valuable products are syngas/hydrogen and liquid fuels. The processes of HTG of low-calorie wastes are beginning to develop, and this process is rather complicated because wastes are characterized by significant heterogeneity [60]. In this regard, HTL with liquid fuel production appears promising. The efficiency of hydrothermal processes significantly depends on the calorific value, ash content, and elemental composition of the biomass. It is obvious that physical and chemical analyses are important for assessing the possibility of processing long-term stored BWW. This article aims to characterize the physicochemical and elemental composition, as well as the thermal properties of BWWs of various storage times, in order to establish the most promising direction for their use.
The novelty and practical value of this work lies in the fact that, for the first time, the properties of BWW of various storage periods are compared, the most common methods of processing and recycling BWW are summarized, as well as the feasibility of using hydrothermal methods and composting for BWW processing.

2. Materials and Methods

Sampling of BWW was conducted from the bark dump body (city Krasnokamsk, Russia), which currently contains 1.5 million m3 or 1.2 million tons of BWW and which occupies an area of 22.3 ha (Figure 1).
The accumulation of BWW took place between 1936 and 2005 (until the closing of the pulp and paper company). The industrial waste disposal facility is located at a distance of 120 m from the residential area of Krasnokamsk city, mostly on the territory of the coastal protection belt of the Votkinsk reservoir. The height of the dump varies from 2 to 21 m.
Sampling was carried out by drilling at three points. Drilling was performed using a mechanical core method using the URB-2A rig (Mashinostroitelnyy zavod im. V.V. Vorovskogo, Yekaterinburg, Russia). An auger-type drill with a diameter of 127 mm was used (Figure 2). When choosing sampling points, the goal was to select wastes characterized by different ages of being in the bark dump body.
Hydrogen index and chemical oxygen demand (COD) were measured in water extract. An aqueous extract was prepared as follows: 5 g of bidistilled water was taken for 1 g of waste and shaken for 5 min. The resulting suspension was filtered through a white tape filter.
The hydrogen index was determined by the potentiometric method using the Expert pH tester (Ekonis-Ekspert, Moscow, Russia).
The COD was estimated based on ISO 6060:1989 by the method of oxidation of organic compounds with potassium dichromate in an acid medium at boiling, followed by titration of the residual amount with Mohr’s salt [61].
Humidity was determined gravimetrically by drying at 104 °C to constant weight. Loss on ignition (LOI) was also determined gravimetrically by calcination at 550 °C, similar to the method described in ASTM-D7348 [62].
Respiration activity was assessed in accordance with OENORM S 2027-4:2012 “Evaluation of waste from mechanical–biological treatment. Part 4: Stability parameters—Respiration activity (AT4)” [63].
Elemental analysis of algae biomass was performed using a CHNS elemental analyzer Elementar Analysensysteme (Germany) model Vario EL Cube. Weighing was carried out on an analytical balance with an accuracy of 0.01 mg. The content of elements was determined based on the area of the chromatographic peaks of N2, CO2, H2O, and SO2 using a calibration straight line constructed using standard compounds. Each sample was examined in three separate repetitions, with mean values reported. The analytical data were processed, and the content of components in the sample was calculated using the software provided by the equipment manufacturer.
To evaluate the calorific value and thermal properties of BWW samples, a simultaneous thermal analysis was carried out in oxidizing (air) and inert (argon) media. The studies were carried out on a NETZSCH STA 449C Jupiter synchronous thermal analyzer (NETZSCH-Gerätebau GmbH, Germany). The analysis parameters are shown in Table 1.

3. Results and Discussion

3.1. Evaluation of Agricultural Potential of BWW

The results of the physicochemical analysis of BWW are presented in Table 2 and Figure 3. Waste age assessment was performed on the basis of the following data: technological plan and register of bark dump filling for the period: 1950–2005.
The waste material sampled from the bark dump had a high moisture content ranging from 60.79% to 74.95%, with an average value of 68.65%. The analysis of the results concludes that the quality of BWW in dumps changes insignificantly over a long period. The pH value does not change significantly and shifts toward neutral values from 6.5 (weighted average for waste with storage period less than 40 years) to 7.5 (weighted average for waste with storage period more than 40 years).
This fact supports the hypothesis that there are no humification processes in the bark dump, because it is accompanied by a pH shift to the acid side, which we did not observe during the physicochemical properties of the waste analyzing. At the same time, we did not observe a significant change in the amount of organic compounds, since the LOI in long-stored BWW differs from the average value for new waste by no more than 5% (the values for new waste and waste with 80 years of storage are 92% and 87%, respectively). The carbon content in BWW stored for over 80 years was 48.13%, which practically does not differ from its content in waste stored for 10 years, which was 47.84%.
With the sufficiently high carbon content, the low level of respiratory activity was observed; thus, the average value of the AT4 parameter was 3.6 mg O2/kg. This ratio indicates that the contained organic molecules have a low potential for destruction, which could be due to their low bioavailability or to the presence of toxicants.
Thus, we can conclude that organic matter mineralization in the bark dump proceeds slowly. Retardation of mineralization is related to anoxic conditions and to a high concentration of organic compounds with bactericidal properties. Anaerobic communities of microorganisms are especially sensitive to the effects of the toxicants. At the same time, it was not possible to identify the patterns in sulfur and nitrogen content change in waste samples from different storage periods, which is related to the different types of raw materials used (at different times, coniferous or birch wood was used in the technological process), as well as possible contamination with waste pulping, which is rich in sulfur and nitrogen.
A slight decline in the amount of hydrogen and oxygen can be observed (Figure 3c,e). The median value of hydrogen content decreased by 9.8%, with oxygen decreasing by 17.5% in the old BWW. This is associated with the partial destruction of readily available organic compounds in anaerobic processes, accompanied by the formation of water, carbon dioxide, methane, and hydrogen.
The most comprehensive studies of changes in the elemental composition and pH of bark were carried out by a group of scientists on the example of bark decomposition in natural conditions of a boreal forest. The authors also found that the carbon concentration in the spruce bark remained virtually unchanged (spruce BWW dominates in the dump under study) [67]. The authors also noted that the pH of bark and wood waste remained practically unchanged for more than 66 years [67].
The ratio of carbon and nitrogen (C:N) is used as integral characteristic of plant-growing substrates. Under normal conditions, this ratio ranges between 8 and 12, with a deviation indicating the soil’s ecological unfavorability. A deviation in the range of 7.5–20 is considered acceptable [68].
Large deviations are detrimental to soil microorganisms. Almost all of them are sensitive to the carbon–nitrogen balance (C:N). Its deviation in any direction from the specified norm indicates the suppression of soil microbiological processes. If the substrate has a low C:N ratio, then ammonia accumulates in the soil substrate, since microorganisms do not have enough carbon-containing compounds to assimilate nitrogen. If, on the contrary, this ratio becomes high, microbial communities are severely deficient in nitrogen [69].
According to compost standards [70,71], the most favorable C:N ratio in composting substrate is 30:1, and this ratio during the composting process changes to 20–18:1. In the BWW, the C:N ratio varies over a wide range from 34 to 306 (with a zonal norm of 11). The obtained results are consistent with the data on the ratio of carbon and nitrogen in the bark of coniferous trees, reflected in the literature [67,72]. Thus, we see that the lack of biologically available nitrogen also inhibits the BWW composting process. The lack of nitrogen during BWW composting could be replenished by mixing with nitrogen-rich substrates (e.g., manure) or by adding mineral forms of nitrogen (e.g., carbonic acid amide).

3.2. Evaluation of BWW Thermal Properties

To evaluate the thermal properties, BWW samples were analyzed using simultaneous thermal analysis in oxygen and inert gas environments (Table 3). An example of a thermogram in an oxygen environment for nine-year-old waste is shown in Figure 4.
Absolutely all samples demonstrated two-stage degradation under oxygen conditions with a maximum average degradation rate of 20–27%/min at a temperature of 330–349 °C. The first peak at temperatures up to 120 °C is associated with the loss of moisture in the samples.
The second peak should be associated with the destruction of the bulk of the organic compounds of hemicellulose and cellulose. The second peak has a shelf in the temperature range of 378–538 °C (average 422.8 °C). This shelf should be associated with the end of the processes of lignin destruction and the combustion of previously formed char.
Barta-Rajnai et al. also noted a two-stage decomposition of the bark in the temperature range of 250–450 °C, with a maximum ratio decomposition at a temperature of 380 °C [66]. However, the HHV established by Barta-Rajnai et al. for the Norway spruce bark was 20.14 MJ/kg, which is 35.6% more than what was obtained in our studies (average value for BWW). This is most likely due to the fact that fresh bark was analyzed in the Barta-Rajnai et al. studies and not old BWW, as in our studies.
Figure 5 depicts a comparison of the dynamics of degradation in an oxygen environment of BWW samples of different storage periods. Figure 5 shows an array of temperature values at which the maximum rate of samples mass loss was observed; this is the extremum of the curve “mass loss/time”.
The lower the temperature where this extermum is observed, the less thermally stable the sample and the lower its degree of mineralization. Obviously, as the storage period increases, the temperature at which we see the most active decomposition of the sample increases, which is related to partial hemicellulose degradation and biomass mineralization.
According to the literature data, the bark of coniferous trees contains 16–23% cellulose, 13–31% hemicellulose, 8–10% polyuronides, 27–33% lignin, and 14–30% extractives [73]. Simultaneously, during storage, wood loses some hemicellulose, which is partially depolymerized when soluble, biologically readily available components are eliminated (mainly mono- trisaccharides). As previously stated, the successful destruction of BWW is significantly hindered by its constituent tannin and guaiacyl lignin. The latter is less prone to degradation compared to conventional lignin, since it contains fewer aryl–aryl bonds and, as a result, a lower redox potential [74,75].
At the same time, we can observe a drop in the total calorific value of BWW (on average by 12 percent) when we examine the thermal effects that accompany the processes of thermal destruction of samples (Figure 6).
The calorie content of the waste directly depends on the content and form of organic compounds of the biomass. Due to the destruction of BWW organic matter, the ratio of organic/inorganic substances in the samples changes, and as a result, we can observe a decrease in HHV (Figure 6) and increase in ash content of the biomass (Table 4). These data indirectly confirm partial mineralization of the organic matter. However, waste mineralization is slow, with only 0.15% of organic matter being mineralized per year. This fact is also confirmed by a slight increase in the ash content of waste over 75 years (by no more than 5.4%).
If we look at the curve of samples mass loss rate in an argon atmosphere, we can clearly distinguish only one stage of thermal destruction, described in Table 2. The absence of the second stage of destruction in argon and the presence of this stage in air is due to the fact that the second stage characterizes the oxidation of pyrocarbon formed in the previous stages, and this process is impossible without oxygen. However, on the DSC curve, we could recognize a bit more peaks. The first two peaks on the DSC curve (280–380 °C and 380–475 °C) most likely correspond to the autoxidation of hemicellulose and cellulose. Furthermore, at temperatures as high as 660 °C, the additional destruction of inorganic matter can be observed. The maximum degradation rate was observed at a temperature of 357–380 °C and was 9–12% per minute. The residual amount of pyrocarbon and ash residue varied significantly within 24.8–48.2%. It was not possible to establish a pattern indicating the relationship between the storage period of waste and the proportion of pyrolysis residue. An example of a thermogram in an argon environment for a sample of 82 years of storage is shown in Figure 7.
To evaluate the feasibility of using BWW as a fuel source, it is worth comparing it with the well-known biomass sources that are actively used as solid fuels or for the production of liquid hydrocarbons. Coniferous wood, biomass of macro- and microalgae, and straw are the closest analogues. A comparison with the above-mentioned types of biomass is presented in Table 4. For BWW in Table 4, we used the average values of the main elements, HHV and ash content.
Due to the low calorific value and high moisture content, BWW biomass has a low potential attractiveness as a solid fuel for direct incineration without pre-conversion. The low calorific value of the waste, taking into account the natural humidity at a level of 68.6%, was 4.49 MJ/kg. The low sulfur and nitrogen concentrations of BWW permit conclusions to be drawn about its prospective applicability for producing liquid and solid fuels in hydrothermal conversion processes.
The preliminary treatment of bark biomass by hydrothermal methods will provide an increase in the specific calorific value of biomass due to the autoxidation of a part of the oxygen-containing compounds and the transition of their conversion products to the liquid phase [83].

4. Conclusions

Processing of primary raw materials on the pulp and paper enterprises gives large volumes of wood waste, consisting mainly of bark (60–70%). Up to 98% of such waste in Russia is landfilled in the environment without any pre-treatment. BWW disposal in bark dumps creates risks of an uncontrolled release of pollutants into the environment [2].
Analysis of the physicochemical properties of BWW on the example of waste from a pulp and paper plant located in the Ural region of Russia (Krasnokamsk city) allowed us to establish that even long-stored waste (80 years or more) does not undergo significant changes during storage in a bark dump. This fact is confirmed by only slight decreases in the LOI (by no more than 5% over more than 80 years of storage) and the specific calorific value of waste (on average by 12%). Mineralization of BWW proceeds slowly (the calculated rate of destruction of organic matter is no more than 0.15% per year), which is associated with the presence of a number of biodegradation inhibitors in the waste, in particular, tannin and guaiacyl lignin. Therefore, the waste of bark dumps for a long time (more than 200 years) will not be significantly subjected to the processes of natural biological destruction, which suggests the relevance of finding ways to rationally process BWW.
An evaluation of the potential for using BWW to produce plant-growing substrates and fertilizers revealed that the waste has a low nitrogen content (average C:N ratio 119) and a high content of difficult-to-oxidize organic matter, which is supported by the following data: with an average content of organic compounds in waste of 91.9% (mean LOI), mean respiratory activity does not exceed 4 mgO2/kg d.m. Thus, BWWs can only be used as a bulking agent when preparing soil mixes with other organic wastes rich in biogenic components (for example, manure). At the same time, preliminary testing to determine their phytotoxicity is essential, because lignin and other bark components might hinder plant development [84].
The thermal properties of BWW were studied, and it was discovered that the waste has a high humidity (61–75%) and a low calorific value (14.33 MJ/kg on d.m. and LHV = 4.5 MJ/kg). This means that the use of traditional thermal methods (pyrolysis, incineration, gasification) will require pre-drying of the waste, resulting in a negative or inefficient energy balance.
At the same time, this waste is characterized by a low ash content (average 8.1%) and high carbon content (average 46.4%), with low contents of nitrogen (average 0.4%) and sulfur (average 0.3%). This allows us to conclude that hydrothermal conversion methods, such as hydrothermal carbonization (HTC), hydrothermal liquefaction (HTL), and hydrothermal gasification (HTG), are promising for the processing and utilization of large volumes of BWW. The high content of carbohydrates in the form of cellulose and hemicellulose and the low content of proteins and fats make it possible to draw conclusions about the advisability of mixing this type of biomass during hydrothermal liquefaction processes with other sources of biomass that are characterized by a high content of proteins (for example, algae). This will achieve a synergistic effect due to the synthesis of ketosamines and their products of further transformation according to Maillard reactions between carbohydrates and proteins [50].
Based on this research, it was found that the most promising directions for the utilization of old BWW should be considered, such as their use as structurants in the production of compost and BWW hydrothermal conversion to obtain hydrochar and liquid fuel. Further studies on the feasibility of old BWW recycling should be devoted to the evaluation of their phytotoxicity and the dependence of this parameter on the storage period, in case of use for compost production. Development of HTL processing of BWW should follow the path of searching for optimal conditions, including the possibility of co-processing with other organic waste and using catalytic systems.

Author Contributions

Conceptualization, Y.K. and O.B.; Formal analysis, S.S.; Funding acquisition, S.N.; Investigation, Y.K., M.K. and M.Y.; Project administration, O.B. and S.S.; Resources, S.S.; Validation, M.K.; Writing—original draft, Y.K. All authors have read and agreed to the published version of the manuscript.

Funding

This research was funded by the Ministry of Science and Higher Education of the Russian Federation, project number FZWM-2021-0016.

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

Not applicable.

Conflicts of Interest

The authors declare no conflict of interest.

References

  1. Babich, O.O.; Kulikova, Y.V.; Sukhikh, S.A.; Kalashnikova, O.B.; Dolganyuk, V.F. Review of research in the field of development of technologies for direct production of liquid fuel from biomass. Herit. Sci. 2021, 80, 41–47. (In Russian) [Google Scholar] [CrossRef]
  2. Maksimov, A.Y.; Maksimova, Y.G.; Shilova, A.V.; Kolesova, O.V.; Simonetti, J. Study of the properties and microbiological composition of bark and wood waste from the Krasnokamsk bark dump. Bull. PNRPU. Chem. Eng. Biotechnol. 2018, 4, 98–112. (In Russian) [Google Scholar] [CrossRef]
  3. Giner-Santonja, G.; Suhr, M.; Klein, G.; Kourti, I.; Gonzalo, M.R.; Roudier, S.; Sancho, L.D. Best Available Techniques (BAT) Reference Document for the Production of Pulp, Paper and Board; Publications Office of the European Union: Luxembourg, 2015; pp. 185–504. [Google Scholar] [CrossRef]
  4. Ministry of Natural Resources of Russia. On the State and Protection of the Environment of the Russian Federation in 2020. State-Donation Report; Ministry of Natural Resources of Russia: Moscow, Russia, 2021; pp. 245–318. (In Russian) [Google Scholar]
  5. BP Statistical Review of World Energy. 2021. Available online: https://www.bp.com/content/dam/bp/business-sites/en/global/corporate/pdfs/energy-economics/statistical-review/bp-stats-review-2021-full-report.pdf (accessed on 10 May 2022).
  6. Clemencon, R. The Two Sides of the Paris Climate Agreement: Dismal Failure or Historic Breakthrough? J. Env. Dev. 2016, 25, 3–24. [Google Scholar] [CrossRef]
  7. Liu, R.; Tian, W.; Kong, S.; Meng, Y.; Wang, H.; Zhang, J. Effects of inorganic and organic acid pretreatments on the hydrothermal liquefaction of municipal secondary sludge. Energ. Convers. Manag. 2018, 174, 661–667. [Google Scholar] [CrossRef]
  8. Mishra, A.; Ghosh, S. Bioethanol production from various lignocellulosic feedstocks by a novel «fractional hydrolysis» technique with different inorganic acids and coculture fermentation. Fuel 2019, 236, 544–553. [Google Scholar] [CrossRef]
  9. Woiciechowski, A.L.; Dalmas, C.J.; Vandenberghe, L.P.S.; Carvalho, D.P.; Sydney, A.C.N.; Letti, L.A.J.; Karp, S.G.; Torres, L.A.Z.; Soccol, C.R. Lignocellulosic biomass: Acid and alkaline pretreatments and their effects on biomass recalcitrance—Conventional processing and recent advances. Bioresour. Technol. 2020, 304, 122848. [Google Scholar] [CrossRef]
  10. Yu, Z.; Du, Y.; Shang, X.; Zheng, Y.; Zhou, J. Enhancing fermentable sugar yield from cassava residue using a two-step dilute ultra-low acid pretreatment process. Ind. Crops. Prod. 2018, 124, 555–562. [Google Scholar] [CrossRef]
  11. Kumar, A.K.; Sharma, S. Recent updates on different methods of pretreatment of lignocellulosic feedstocks: A review. Bioresour. Bioprocess. 2017, 4, 7. [Google Scholar] [CrossRef]
  12. Chen, Z.; Jacoby, W.A.; Wan, C. Ternary deep eutectic solvents for effective biomass deconstruction at high solids and low enzyme loadings. Bioresour. Technol. 2019, 279, 126. [Google Scholar] [CrossRef]
  13. Kolesnikova, A.V. Analysis of the formation and use of wood waste at the enterprises of the Russian timber industry. Top. Issues Econ. Sci. 2013, 33, 116–120. (In Russian) [Google Scholar]
  14. Tarasov, D.; Leitch, M.; Fatehi, P. Lignin-carbohydrate complexes: Properties, applications, analyses, and methods of extraction: A review. Biotechnol. Biofuels 2018, 11, 269. [Google Scholar] [CrossRef] [PubMed]
  15. Dibyajyoti, H.M.; Kumar, P. Lignocellulosic conversion into value-added product. Process. Biochem. 2019, 89, 120–150. [Google Scholar] [CrossRef]
  16. Gu, B.J.; Dhumal, G.S.; Wolcott, M.P.; Ganjyal, G.M. Disruption of lignocellulosic biomass along the length of the screws with different screw elements in a twinscrew extruder. Bioresour. Technol. 2019, 275, 266–271. [Google Scholar] [CrossRef]
  17. Kamali, M.; Garmeio, T.; Costa, M.E.; Capela, I. Anaerobic digestion of pulp and paper mill wastes—An overview of the developments and improvement opportunities. Chem. Eng. J. 2016, 298, 162–182. [Google Scholar] [CrossRef]
  18. Hu, Y.; Wang, S.; Li, J.; Wang, Q.; He, Z.; Feng, Y. Co-pyrolysis and co- hydrothermal liquefaction of seaweeds and rice husk: Comparative study towards enhanced biofuel production. J. Anal. Appl. Pyrol. 2018, 129, 162–170. [Google Scholar] [CrossRef]
  19. Huang, S.; Liu, T.; Peng, B.; Geng, A. Enhanced ethanol production from industrial lignocellulose hydrolysates by a hydrolysate-cofermenting Saccharomyces cerevisiae strain. Bioproc. Biosyst. Eng. 2019, 42, 883–896. [Google Scholar] [CrossRef] [PubMed]
  20. Rynk, R.; Schwarz, M.; Richard, T.; Cotton, M.; Halbach, T.; Siebert, S. Compost feedstocks. Compost. Handb. 2022, 85, 103–157. [Google Scholar] [CrossRef]
  21. Kulikowska, D.; Sindrewicz, S. Effect of barley straw and coniferous bark on humification process during sewage sludge composting. Waste Manag. 2018, 79, 207–213. [Google Scholar] [CrossRef]
  22. Bohacz, J. Composts and Water Extracts of Lignocellulosic Composts in the Aspect of Fertilization, Humus-Forming, Sanitary, Phytosanitary and Phytotoxicity Value Assessment. Waste Biomass Valoris. 2019, 10, 334. [Google Scholar] [CrossRef]
  23. Pengqi, L.; Yufei, X.; Jian, L.; Xinjing, Q.; Shengyu, D.; Jun, Y. Effect of Different Microbial Inoculants and Particle Size on Compost of Acacia mangium. Chin. J. Trop. Crops 2019, 40, 39–44. [Google Scholar]
  24. Sang, S.; Zhuang, X.; Chen, H.; Qin, Y.; Cao, J.; Fan, F.; Lan, T. Effect of supramolecular structural changes during the crystalline transformation of cellulose on its enzymatic hydrolysis. Ind. Crops Prod. 2022, 180, 114687. [Google Scholar] [CrossRef]
  25. Novozhilov, E.V.; Sinelnikov, I.G.; Aksenov, A.S.; Chukhchin, D.G.; Tyshkunova, I.V.; Rozhkova, A.M.; Osipov, D.O.; Zorov, I.N.; Sinitsyn, A.P. Biocatalytic conversion of sulfate cellulose using complex biocatalysts based on recombinant Penicillium verruculosum enzyme preparations. Catal. Ind. 2015, 15, 78–83. [Google Scholar]
  26. Houfani, A.A.; Andersb, N.; Spiessb, A.C.; Baldrianc, P.; Benallaouaa, S. Insights from enzymatic degradation of cellulose and hemi cellulose to fermentable sugars—A review. Biomass Bioenerg. 2020, 134, 105481. [Google Scholar] [CrossRef]
  27. Kaltschmitt, M. Energy from Organic Materials (Biomass). In Encyclopedia of Sustainability Science and Technology, 2nd ed.; Springer: Berlin, Germany, 2019. [Google Scholar] [CrossRef]
  28. Cedeno, R.F.; Belon de Siqueira, B.; Chavez, G.E.; Ulises, M.I.; Moreira, R.L.; Galán, J.; Masarin, F. Recovery of cellulose and lignin from Eucalyptus by-product and assessment of cellulose enzymatic hydrolysis. Renew. Energ. 2022, 193, 807–820. [Google Scholar] [CrossRef]
  29. Nitsos, C.K.; Lazaridis, P.A.; MachAigner, A.; Matis, K.A.; Trianta, K.S. Enhancing lignocellulosic biomass hydrolysis by hydrothermal pretreatment, extraction of surface lignin, wet milling and production of cellulolytic enzymes. Chem. Sus. Chem. 2019, 12, 1179–1195. [Google Scholar] [CrossRef]
  30. Donev, E.; Gandla, M.L.; Jonsson, L.J.; Mellerowicz, E.J. Engineering non-cellulosic polysaccharides of wood for the biorefinery. Front. Plant. Sci. 2018, 9, 1537. [Google Scholar] [CrossRef]
  31. The Fifth Assessment Report (AR5) of the United Nations Intergovernmental Panel on Climate Change (IPCC). 2014. Available online: https://www.ipcc.ch/assessment-report/ar5/ (accessed on 10 May 2022).
  32. Aquila, A.; Twardowski, T.; Wohlgemuth, R. Bioeconomy for sustainable development. Biotechnol. J. 2019, 14, 1800638. [Google Scholar] [CrossRef]
  33. Yucai, H.; Cui-Luan, M.; Bin, Y. Pretreatment Process and Its Synergistic Effects on Enzymatic Digestion of Lignocellulosic. In Fungal Cellulolytic Enzymes; Springer: Berlin, Germany, 2018; pp. 1–25. [Google Scholar] [CrossRef]
  34. Zavyalov, A.V.; Rykov, S.V.; Lunina, N.A.; Sushkova, V.I.; Yarotsky, S.V.; Berezina, O.V. Plant polysaccharide xyloglucan and enzymes that hydrolyze it (review). Russ. J. Bioorg. Chem. 2019, 45, 845–859. [Google Scholar] [CrossRef]
  35. Castello, D.; Haider, M.; Rosendahl, L. Catalytic upgrading of hydrothermal liquefaction biocrudes: Different challenges for different feedstocks. Renew. Energ. 2019, 141, 420–430. [Google Scholar] [CrossRef]
  36. Dahman, Y.; Syed, K.; Begum, S.; Roy, P.; Mohtasebi, B. Biofuels: Their characteristics and analysis. Biomass. In Biopolymer-Based Materials, and Bioenergy; Elsevier: Berlin, Germany, 2019; pp. 277–325. [Google Scholar]
  37. Danquah, J.; Roberts, C.; Appiah, M. Elephant Grass (Pennisetum purpureum): A Potential Source of Biomass for Power Generation in Ghana. Curr. J. Appl. Sci. Technol. 2018, 30, 1–12. [Google Scholar] [CrossRef]
  38. De Laporte, A.V.; Ripplinger, D.G. The effects of site selection, opportunity costs and transportation costs on bioethanol production. Renew. Energ. 2019, 131, 73–82. [Google Scholar] [CrossRef]
  39. Jellali, S.; El-Bassi, L.; Charabi, Y.; Usman, M.; Khiari, B.; Al-Wardy, M.; Jeguirim, M. Recent advancements on biochars enrichment with ammonium and nitrates from wastewaters: A critical review on benefits for environment and agriculture. J. Environ. Manag. 2022, 305, 114368. [Google Scholar] [CrossRef] [PubMed]
  40. Basu, P. Biomass Gasification, Pyrolysis and Torrefaction; Elsevier: London, UK, 2018; pp. 49–87. [Google Scholar]
  41. Venderbosch, R.H. Fast pyrolysis. Thermochemical processing of biomass: Conversion into fuels, chemicals and power. In Thermochemical Processing of Biomass; Brown, R., Ed.; John Wiley and Sons: Hoboken, NJ, USA, 2019; pp. 175–206. [Google Scholar]
  42. Matayeva, A.; Basile, F.; Cavani, F.; Bianchi, D.; Chiaberge, S. Development of upgraded bio-oil via liquefaction and pyrolysis. In Horizons in Sustainable Industrial Chemistry and Catalysis; Elsevier: London, UK, 2019; pp. 231–256. [Google Scholar] [CrossRef]
  43. Zhang, L.; Li, S.; Ding, H.; Zhu, X. Two-step pyrolysis of corncob for value-added chemicals and high-quality bio-oil: Effects of alkali and alkaline earth metals. Waste Manag. 2019, 87, 709–718. [Google Scholar] [CrossRef] [PubMed]
  44. Kulikova, Y.; Sukhikh, S.; Ivanova, S.; Babich, O.; Sliusar, N. Review of Studies on Joint Recovery of Macroalgae and Marine Debris by Hydrothermal Liquefaction. Appl. Sci. 2022, 12, 569. [Google Scholar] [CrossRef]
  45. Liang, W.; Wang, G.; Jiao, K.; Ning, X.; Zhang, J.; Guo, X.; Li, J.; Wang, C. Conversion mechanism and gasification kinetics of biomass char during hydrothermal carbonization. Renew. Energ. 2021, 173, 318–328. [Google Scholar] [CrossRef]
  46. Azzaz, A.; Khiari, B.; Jellali, S.; Ghimbeu, C.; Jeguirim, M. Hydrochars production, characterization and application for wastewater treatment: A review. Renew. Sust. Energ. Rev. 2020, 127, 109882. [Google Scholar] [CrossRef]
  47. Marulanda, V.A.; Gutierrez, C.D.B.; Alzate, C.A.C. Thermochemical, Biological, Biochemical and Hybrid Conversion Methods of bio-derived molecules into renewable fuels. In Advanced Bioprocessing for Alternative Fuels; Elsevier: London, UK, 2019; pp. 59–81. [Google Scholar] [CrossRef]
  48. Moriarty, P.; Honnery, D. Global renewable energy resources and use in 2050. In Managing Global Warming; Elsevier: London, UK, 2019; pp. 221–235. [Google Scholar] [CrossRef]
  49. Kargbo, H.; Harris, J.S.; Phan, N.A. Dropin-fuel production from biomass Critical review on technoeconomic feasibility and sustainability. Renew. Sustain. Energy Rev. 2021, 135, 110168. [Google Scholar] [CrossRef]
  50. Yang, J.; He, Q.S.; Corscadden, K.; Niu, H.; Lin, J.; Astatkie, T. Advanced models for the prediction of product yield in hydrothermal liquefaction via a mixture design of biomass model components coupled with process variables. Appl. Energy 2019, 233–234, 906–915. [Google Scholar] [CrossRef]
  51. Basar, I.A.; Liu, H.; Carrere, H.; Trably, E.; Eskicioglu, C. A review on key design and operational parameters to optimize and develop hydrothermal liquefaction of biomass for biorefinery applications. Green Chem. 2021, 23, 1404. [Google Scholar] [CrossRef]
  52. Tai, L.; Caprariis, B.; Scarsella, M.; de Filippis, P.; Marra, F. Improved Quality Bio-Crude from Hydrothermal Liquefaction of Oak Wood Assisted by Zero-Valent Metals. Energy Fuels 2021, 35, 10023–10034. [Google Scholar] [CrossRef]
  53. Xu, Y.H.; Li, M.F. Hydrothermal liquefaction of lignocellulose for value-added products: Mechanism, parameter and production application. Bioresour. Technol. 2021, 342, 126035. [Google Scholar] [CrossRef] [PubMed]
  54. Santosa, D.M.; Wendt, L.M.; Wahlen, B.D.; Schmidt, A.J.; Billing, J.; Kutnyakov, I.V.; Hallen, R.T.; Thorson, M.R.; Oxford, T.L.; Anderson, D.B. Impact of storage and blending of algae and forest product residue on fuel blendstock production. Algal Res. 2022, 62, 102622. [Google Scholar] [CrossRef]
  55. Chen, C.; Zhu, J.; Jia, S.; Mi, S.; Tong, Z.; Li, Z.; Li, M.; Zhang, Y.; Hu, Y.; Huang, Z. Effect of ethanol on Mulberry bark hydrothermal liquefaction and bio-oil chemical compositions. Energy 2018, 162, 460–475. [Google Scholar] [CrossRef]
  56. Stigsson, C.; Furusjö, E.; Börjesson, P. A model of an integrated hydrothermal liquefaction, gasification and Fischer-Tropsch synthesis process for converting lignocellulosic forest residues into hydrocarbons. Biores. Technol. 2022, 353, 126070. [Google Scholar] [CrossRef] [PubMed]
  57. Lee, C.; Conradie, A.; Lester, E. Review of supercritical water gasification with lignocellulosic real biomass as the feedstocks: Process parameters, biomass composition, catalyst development, reactor design and its challenges. J. Chem. Eng. 2021, 415, 128837. [Google Scholar] [CrossRef]
  58. Nunes, L. Biomass gasification as an industrial process with effective proof-of-concept: A comprehensive review on technologies, processes and future developments. Res. Eng. 2022, 14, 100408. [Google Scholar] [CrossRef]
  59. Hossain, M. Promotional effects of Ce on Ni Ce/γAl2O3 for enhancement of H2 in hydrothermal gasification of biomass. Int. J. Hydrogen Energy 2018, 43, 6088–6095. [Google Scholar] [CrossRef]
  60. Tan, E.C. Sustainable Process Design for Biofuel Production via Syngas Conversion Pathway; No. NREL/PR-5100–74250; National Renewable Energy Lab. (NREL): Golden, CO, USA, 2019. [Google Scholar]
  61. Water Quality–Determination of The Chemical Oxygen Demand. ISO 6060:1989. Available online: https://www.iso.org/standard/12260.html (accessed on 10 May 2022).
  62. ASTM-D7348; Standard Test Methods for Loss on Ignition (LOI) of Solid Combustion Residues. ASTM International: West Conshohocken, PA, USA, 2021; pp. 1–7. [CrossRef]
  63. Binner, E.; Bohm, K.; Lechner, P. Large scale study on measurement of respiration activity (AT4) by Sapromat and OxiTop. Waste Manag. 2012, 32, 1752–1759. [Google Scholar] [CrossRef]
  64. NRCS-USDA. National Soil Survey Handbook. Available online: https://www.nrcs.usda.gov/wps/PA_NRCSConsumption/download?cid=stelprdb1270585&ext=pdf (accessed on 1 February 2022).
  65. Kondratyeva, M.A.; Bazukova, N.V. Mapping of soils since its inception to our days (on the example of the Perm region). Russ. J. Appl. Ecol. 2019, 3, 28–34. [Google Scholar]
  66. IUSS Working Group WRB. World Reference Base for Soil Resources 2014, Update 2015. International Soil Classification System for Naming Soils and Creating Legends for Soil Maps. World Soil Resources Reports No. 106, Rome. Available online: https://www.fao.org/3/i3794en/I3794en.pdf (accessed on 10 May 2022).
  67. Romashkin, I.; Shorohova, E.; Kapitsa, E.; Galibina, N.; Nikerova, K. Carbon and nitrogen dynamics along the log bark decomposition continuum in a mesic old-growth boreal forest. Eur. J. Res. 2018, 137, 643–657. [Google Scholar] [CrossRef]
  68. Pognani, M.; Barrena, R.; Font, X.; Adani, F.; Scaglia, B.; Sánchez, A. Evolution of organic matter in a full–scale composting plant for the treatment of sewage sludge and biowaste by respiration techniques and pyrolysis–GC/MS. Bioresour. Technol. 2011, 102, 4536–4543. [Google Scholar] [CrossRef] [PubMed]
  69. Zhang, W.; Yu, C.; Wang, X.; Hai, L. Increased abundance of nitrogen transforming bacteria by higher C/N ratio reduces the total losses of N and C in chicken manure and corn stover mix composting. Bioresour. Technol. 2020, 297, 122410. [Google Scholar] [CrossRef] [PubMed]
  70. Akratos, C.; Tekerlekopoulou, A.; Vasiliadou, I.; Vayenas, D. Cocomposting of olive mill waste for the production of soil amendments. Olive Mill Waste 2017, 11, 161–182. [Google Scholar] [CrossRef]
  71. Dickson, N.; Richard, T.; Kozlowski, R. Composting to Reduce the Waste Stream: A Guide to Small Scale Food and Yard Waste Composting; NEARS: Ithaca, NY, USA, 1991; p. 46. [Google Scholar]
  72. Zhao, D.; Kane, M.; Teskey, R.; Markewitz, D.; Greene, D.; Borders, B. Impact of management on nutrients, carbon, and energy in aboveground biomass components of mid-rotation loblolly pine (Pinus taeda L.) plantations. Annu. For. Sci. 2014, 71, 843–851. [Google Scholar] [CrossRef]
  73. Barta-Rajnai, E.; Wang, L.; Sebestyén, Z.; Barta, Z.; Khalil, R.; Skreiberg, Ø.; Grønli, M.; Jakab, E.; Czégény, Z. Comparative study on the thermal behavior of untreated and various torrefied bark, stem wood, and stump of Norway spruce. Appl. Energy 2017, 204, 1043–1054. [Google Scholar] [CrossRef]
  74. Vane, C.H.; Drage, T.C.; Snape, C.E. Bark decay by the white-rot fungus Lentinula edodes: Polysaccharide loss, lignin resistance and the unmasking of suberin. Int. Biodeterior. Biodegrad. 2006, 57, 14–23. [Google Scholar] [CrossRef]
  75. Vane, C.H.; Martin, S.C.; Abbott, G.D. Degradation of Lignin in Wheat Straw during Growth of the Oyster Mushroom (Pleurotus ostreatus) Using Off-line Thermochemolysis with Tetramethylammonium Hydroxide and Solid-State 13C NMR. J. Agric. Food Chem. 2001, 49, 2709–2716. [Google Scholar] [CrossRef]
  76. Kulikova, Y.; Sukhikh, S.; Kalashnikova, O.; Chupakhin, E.; Ivanova, S.; Chubarenko, B.; Gorbunova, J.; Babich, O. Assessment of the Resource Potential of Baltic Sea Macroalgae. Appl. Sci. 2022, 12, 3599. [Google Scholar] [CrossRef]
  77. González, J.F.; Cuello, T.B.; Calderón, A.J.; Calderón, M.; González, J.; Carmona, D. Cultivation of Autochthonous Microalgae for Biomass Feedstock: Growth Curves and Biomass Characterization for Their Use in Biorefinery Products. Energies 2021, 14, 4567. [Google Scholar] [CrossRef]
  78. Goldšteins, L.; Dzenis, M.G.; Valdmanis, R.; Zaķe, M.; Arshanitsa, A. Thermo-Chemical Conversion of Microwave Activated Biomass Mixtures. IOP Conf. Ser. Mater. Sci. Eng. 2018, 355, 12018. [Google Scholar] [CrossRef]
  79. Portnov, D.; Subbotin, D.; Kazakov, A.; Zavorin, A. The Peat and Wood Gasification at Different Conditions of the Pyrolysis Process. MATEC Web Conf. 2015, 37, 1043. [Google Scholar] [CrossRef]
  80. Therasme, O.; Eisenbies, M.; Volk, T. Overhead Protection Increases Fuel Quality and Natural Drying of Leaf-On Woody Biomass Storage Piles. Forests 2019, 10, 390. [Google Scholar] [CrossRef]
  81. Cai, H.; Yang, K.; Zhang, Q.; Zhao, K.; Gu, S. Pyrolysis Characteristics of Typical Biomass Thermoplastic Composites. Res. Phys. 2017, 7, 3230–3235. [Google Scholar] [CrossRef]
  82. Hendriyana, M. Effect of Equivalence Ratio on the Rice Husk Gasification Performance Using Updraft Gasifier with Air Suction Mode. J. Bahan Alam Terbarukan 2020, 9, 30–35. [Google Scholar] [CrossRef]
  83. Anastasakis, K.; Biller, P.; Madsen, R.; Glasius, M.; Johannsen, I. Continuous Hydrothermal Liquefaction of Biomass in a Novel Pilot Plant with Heat Recovery and Hydraulic Oscillation. Energies 2018, 11, 2695. [Google Scholar] [CrossRef]
  84. Yadav, S.; Chandra, R. Detection and assessment of the phytotoxicity of residual organic pollutants in sediment contaminated with pulp and paper mill effluent. Environ. Monit. Assess. 2018, 190, 581. [Google Scholar] [CrossRef]
Figure 1. Location of the studied bark dump and sampling site (primary cartographic basis from the website https://www.google.com/maps/, accessed on 18 March 2022).
Figure 1. Location of the studied bark dump and sampling site (primary cartographic basis from the website https://www.google.com/maps/, accessed on 18 March 2022).
Plants 11 01549 g001
Figure 2. Sampling process: (a) URB-2A drilling rig; (b) general view of the drilled core; (c) BWW condition and structure.
Figure 2. Sampling process: (a) URB-2A drilling rig; (b) general view of the drilled core; (c) BWW condition and structure.
Plants 11 01549 g002
Figure 3. Results of physicochemical analysis of BWW samples: (a) loss on ignition; (b) pH; (c) carbon and oxygen content; (d) sulfur and nitrogen content; (e) hydrogen content; (f) carbon to nitrogen ratio.
Figure 3. Results of physicochemical analysis of BWW samples: (a) loss on ignition; (b) pH; (c) carbon and oxygen content; (d) sulfur and nitrogen content; (e) hydrogen content; (f) carbon to nitrogen ratio.
Plants 11 01549 g003
Figure 4. Results of simultaneous thermal analysis in the air atmosphere on the example of BWW with a nine-year storage period.
Figure 4. Results of simultaneous thermal analysis in the air atmosphere on the example of BWW with a nine-year storage period.
Plants 11 01549 g004
Figure 5. Change in the samples’ thermal stability.
Figure 5. Change in the samples’ thermal stability.
Plants 11 01549 g005
Figure 6. Changing of the BWW high calorific value.
Figure 6. Changing of the BWW high calorific value.
Plants 11 01549 g006
Figure 7. Results of simultaneous thermal analysis in the air atmosphere on the example of BWW with an 82-year storage period.
Figure 7. Results of simultaneous thermal analysis in the air atmosphere on the example of BWW with an 82-year storage period.
Plants 11 01549 g007
Table 1. Simultaneous thermal analysis conditions.
Table 1. Simultaneous thermal analysis conditions.
ParameterValue
Initial temperature:30/40 °C
Dynamic segment:1000 °C
Heating rate20 degrees/min
Furnace gas flow rate40 mL/min air/argon
PanPtRh20 85 µL, with lead
Table 2. Results of the physicochemical analysis of BWW samples.
Table 2. Results of the physicochemical analysis of BWW samples.
Depth, mAge, YearsHumidity,%AT4, mgO2/kgpHLOI,%C,%H,%N,%S,%O,%C:N
Well 1
11062.027.895.4497.9149.966.66900.02441.26-
31566.266.66.8298.7149.546.5620042.61-
51762.994.36.8997.2549.216.5650041.48-
Well 2
1960.793.596.1269.2346.155.85800.21138.78-
31065.24.16.8598.949.676.3420.230.88541.77216
51567.767.837.0293.0548.976.3490.160.92936.64306
71769.6 6.9591.8749.226.3450.231.22834.85214
92971.254.86.6193.4948.485.9220.650.88537.5575
114069.851.344.7084.2944.145.1431.30.333.4134
135074.954.176.5891.3249.576.1830.550.47234.5590
156074.773.886.1892.3249.136.1540.590.52335.9283
176768.037.136.4493.0749.266.020.660.23136.9075
197371.51.857.0496.5449.596.0890.610.12640.1381
217873-7.7894.5548.916.1510.560.14138.7987
Well 3
11762.721.287.5567.3343.912.9470.420.58822.41105
32970.911.617.7690.4446.895.3180.580.06837.5881
54069.492.737.5982.8747.765.3050.530.05329.2290
75066.081.66.966.9344.734.9550.490.48117.7491
96069.684.897.395.0748.285.5250.560.08840.6286
116770.382.297.5185.4740.484.5920.520.23680.1278
137370.151.727.5790.5947.115.0660.240.02438.15196
157866.531.27.287.6547.25.4370.370.05834.59128
178270.581.177.0587.7448.45.2870.350.2333.47138
198573.07-7.5986.4747.865.4350.380.2632.54126
Podzolic soils 1 [64,65,66] 5.716.012.1n/d1.37n/dn/d11
Dark humus soils 2 [64,65,66] 7.349.250.8 1.27n/dn/d23
1 Average for zonal podzolic soils. 2 Average for zonal dark humus soils.
Table 3. Results of the thermal analysis of BWW samples in the air and in argon.
Table 3. Results of the thermal analysis of BWW samples in the air and in argon.
Waste Storage
Period, Years
Atm.Number of
Main Stages
t1t2tmax∆m, %Ash, %HHV, KJ/g
Well 110O2114837234152.64.815.71
237160043335.5
Ar117640937450.529.7
15O2116237434253.54.516.04
237560042935
Ar117641738051.729.9
17O2115437634956.74.115.92
237651640233.7
Ar117441537952.426.9
Well 29O2115737633249.6913.21
237660043834.8
Ar116641236450.931.4
10O2115637633056.87.714.24
237760047834.5
Ar117141537858.824.8
15O21152364323539.213.93
236460048936.8
Ar115041335754.426.1
17O2114638029553.4713.84
238060045036.6
Ar113339230950.127.1
29O2115037133549.19.815.23
237262538636
Ar117041637546.434.2
40O2117236432937.317.913.97
236560053536.6
Ar117843836935.245.7
50O2116037833855.45.715.38
237960039134.1
Ar116641737550.831.3
60O2116037633653.38.515.05
237560137835.1
Ar116941138050.930.9
67O2116438233953.5715.65
238660040234.9
Ar117241637748.832.1
73O2115138134067.415.218.86
238260042342
Ar117441837852.629.7
Well 278O2115137633755.25.615.39
237660039032.7
Ar117041737649.831.6
Well 317O2117438033827.948.27.71
238060053817.9
Ar117741937722.262.2
29O21149378337559.215.61
237860039031.3
Ar116842137951.132.6
40O2116138233954.39.714.94
238360039529.6
Ar116142137447.133.9
50O211613813364231.611.17
238060038121.7
Ar116242836435.748.2
60O2115138034055.86.715.402
238060039531.3
Ar117041937847.831.4
67O2115037233744.122.110.966
237260038125.7
Ar116141837237.146
73O2116237733549.515.514.457
237760041330.9
Ar116241737045.836.1
78O2115537833856.48.513.761
237960038729.7
Ar116141937851.930.4
82O2115837233550.910.614.483
237260040734.4
Ar116142037444.636.4
85O2115838033662.14.713.102
238060043729.1
Ar115442037751.231.1
Atm., atmosphere in which thermal analysis was carried out (oxygen or argon); number of main stages, the number of main biomass destruction stages that were determined by the number of main peaks on the differential scanning calorimetric curve (mW/mg). Imperceptible and weakly expressed stages were discarded in the analysis. t1 and t2, temperature of the beginning and end of the stage; tmax, temperature at which the maximum mass loss rate was observed for the sample; ∆m, total mass loss of the sample at this stage.
Table 4. Comparison of thermal properties of BWW samples with analogues.
Table 4. Comparison of thermal properties of BWW samples with analogues.
SampleSource Content, %
CHNSO HHV, MJ/kgAsh, %
BWWOwn research46.24.990.440.2148.114.8511.7
Furcellaria[76]37.525.823.603.0050.059.137.8
Scenedesmus sp. [77]46.36.813.280.28 21.57.0
Peat pellets[78]58.835.121.11 36.9321.243.02
Coniferous wood[78]48.5611.840.70.0638.8519.520.64
Poplar [79,80]51.606.000.600.0241.7018.33.77
Rice husk[81,82]49.406.200.300.4043.7015.723.98
Wheat straw[78]46.625.091.310.1142.7218.474.26
Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Share and Cite

MDPI and ACS Style

Kulikova, Y.; Sukhikh, S.; Babich, O.; Yuliya, M.; Krasnovskikh, M.; Noskova, S. Feasibility of Old Bark and Wood Waste Recycling. Plants 2022, 11, 1549. https://doi.org/10.3390/plants11121549

AMA Style

Kulikova Y, Sukhikh S, Babich O, Yuliya M, Krasnovskikh M, Noskova S. Feasibility of Old Bark and Wood Waste Recycling. Plants. 2022; 11(12):1549. https://doi.org/10.3390/plants11121549

Chicago/Turabian Style

Kulikova, Yuliya, Stanislav Sukhikh, Olga Babich, Margina Yuliya, Marina Krasnovskikh, and Svetlana Noskova. 2022. "Feasibility of Old Bark and Wood Waste Recycling" Plants 11, no. 12: 1549. https://doi.org/10.3390/plants11121549

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop