The Impacts of Calamity Logging on the Sustainable Development of Spruce Fuel Biomass Prices and Spruce Pulp Prices in the Czech Republic

Currently, due to the calamity of unplanned harvesting, the amount of biomass from wood products has increased. Forests occupy 33.7% of the total area of the Czech Republic; therefore, wood and non-wood forest products are important renewables for the country. Wood biomass consists mainly of branches and bark that are not used in the wood or furniture industry. However, it can be used in bioenergy, including wood processing for fuel. As spruce production in the Czech Republic increased from the planned 15.5 million to almost 36.8 million trees in 2020, the price of wood biomass can be expected to be affected. This study aims to develop a predictive model for estimating the decline in the price of wood biomass for wood processors, such as firewood or sawdust producers, as well as for the paper industry. Wood biomass prices are falling with each additional million m3 of spruce wood harvested, as is the decline in wood pulp, which is intended for the paper and packaging industries. The proposed predictive model based on linear regressions should determine how the price of wood biomass will decrease with each additional million harvested spruce trees in the Czech Republic. This tool will be used for practical use in the forestry and wood industry. The linear regression model is suitable for practical forestry use due to its simplicity and high informative value. The aim of the research is to model the dependence of the prices of firewood in the form of wood briquettes and pellets for domestic and industrial processing, as well as the prices of wood pulp on the volume of unplanned logging. It is a guide for the practice of how to use excess spruce wood from unplanned mining in the field of alternative processing with a sustainable aspect for households or heat production for households. The intention is to carry out modelling in such a way that it does not include prices of higher quality wood assortments, which are intended for the woodworking industry.

Influence of sample preparation process on basic properties of biofuels

The characteristic properties of non-wood biomass used in combustion processes are monitored, such as water content, ash, volatile matter. Biomass is usually not homogenous and of suitable dimensions for these determinations. This is the reason for the necessary adjustment of samples for analysis. But modifying the samples may change their properties. In this publication, the influence of the grinding process in a rotor mill on the content of water, volatile matter and ash in non-wood biomass samples was studied. Samples of flax, Crambe abyssinica, amaranth and rye were analyzed. All analyses showed moisture loss from the sample during grinding and in the case of flax, the loss of volatile matter was observed. It means the rotor mill is suitable for sample preparation prior to analysis. But for oil plants it is necessary to choose another mill or adjustment method.

HETEROGENEOUS CATALYTIC FRACTIONATION OF BIRCH-WOOD BIOMASS INTO MICROCRYSTALLINE CELLULOSE, XYLOSE AND ENTEROSORBENTS

For the first time, it was proposed to fractionate the main components of birch wood into microcrystalline cellulose, xylose and enterosorbents by integrating heterogeneous catalytic processes of acid hydrolysis and peroxide delignification of wood biomass. The hydrolysis of wood hemicelluloses into xylose is carried out at a temperature of 150 °C in the presence of a solid acid catalyst Amberlyst® 15. Then the lignocellulosic product undergoes peroxide delignification in a "formic acid – water" medium in the presence of a solid TiO2 catalyst to obtain microcrystalline cellulose (MCC) and soluble lignin. Under the determined optimal conditions (100 °С, Н2О2 – 7.2 wt.%, НСООН – 37.8 wt.%, LWR 15, time 4 h), the yield of MCC reaches 64.5 wt.% and of organosolvent lignin 11.5 wt% from the weight of prehydrolyzed wood. By the treatment of organosolvent lignin with a solution of 0.4% NaHCO3 or hot water the enterosorbents were obtained, whose sorption capacity for methylene blue (97.7 mg/g) and gelatin (236.7 mg/g) is significantly higher than that of the commercial enterosorbent Polyphepan (44 mg/g and 115 mg/g, respectively). The products of catalytic fractionation of birch wood are characterized by physicochemical (FTIR, XRD, SEM, GC) and chemical methods.

Determination of Riparian Vegetation Biomass from an Unmanned Aerial Vehicle (UAV)

The need to rely on accurate information about the wood biomass available in riparian zones under management, inspired the land reclamation authority of southern Tuscany to develop a research based on the new remote sensing technologies. With this aim, a series of unmanned aerial vehicle (UAV) flight campaigns flanked by ground-data collection were carried out on 5 zones and 15 stream reaches belonging to 3 rivers and 7 creeks, being representative of the whole area under treatment, characterized by a heterogeneous spatial distribution of trees and shrubs of different sizes and ages, whose species’ mix is typical of this climatic belt. A careful preliminary analysis of the zones under investigation, based on the available local orthophotos, followed by a quick pilot inspection of the riverbank segments selected for trials, was crucial for choosing the test sites. The analysis of a dataset composed of both measured and remotely sensed acquired parameters allowed a system of four allometric models to be built for estimating the trees’ biomass. All four developed models showed good results, with the highest correlation found in the fourth model (Model 4, R2 = 0.63), which also presented the lowest RMSE (0.09 Mg). The biomass values calculated with Model 4 were in line with those provided by the land reclamation authority for selective thinning, ranging from 38.9 to 70.9 Mg ha−1. Conversely, Model 2 widely overestimated the actual data, while Model 1 and Model 3 offered intermediate results. The proposed methodology based on these new technologies enabled an accurate estimation of the wood biomass in a riverbank environment, overcoming the limits of a traditional ground monitoring and improving management strategies to benefit the river system and its ecosystems.

Pilot Scale Production of Precast Concrete Elements with Wood Biomass Ash

Downsizing fossil fuel dependence and greenhouse gas emissions is at the forefront of a sustainable future. The expansion of renewable energy while striving to minimize dependence on fossil fuels has led to biomass taking the lead among renewable energy sources, with wood having the broadest application. Along with the growing trend of using biomass as a renewable energy source, the combustion of wood biomass results in wood biomass ash (WBA), leading to compelling amounts of waste. In this study, the technical feasibility of fly WBA from different Croatian power plants was analyzed to evaluate its potential use in precast concrete drainage elements and curb units. By implementing a performance-based design, the influence of various factors in thermal processing of wood biomass was investigated, together with a detailed characterization of WBA in order to assess the feasibility of using WBA as a secondary raw material in a large-scale industrial batching plant. The compressive strength and durability properties (water absorption, permeability, and freeze–thaw resistance) of concrete mixtures with WBA as a replacement for 15 wt% cement were evaluated and compared with the precast concrete manufacturer’s technical requirements. The main concerns identified were compositional inconsistency of WBA, workability downturn, delay in initial reactivity rate, and increased water absorption. Concrete with WBA based on a circular design has been found to be a viable solution to cement depletion, stepping up from recycling to reuse of industrial waste.

USE OF LOGGING WASTE IN TECHNOLOGIES FOR DEEP CHEMICAL PROCESSING OF WOOD

The study presents theoretical aspects and modern technologies for processing wood biomass, considers the possibility of obtaining wood chips from felling residues of cutting areas, in particular technological chips that meet the GOST 15815: 1983 “Technological chips. Specifications" standard for use as raw materials in the production of fiberboard. Wood fiber obtained from similar in size and quality indicators according to GOST 15815: 1983 technological chips, pre-treated in a defibrator, was subjected to a refining process at a low concentration, in particular using the developed design of the disks of the refiner of fibrillating action while regulating the main parameters of the process. The resulting wood-fiber mass was characterized by an improvement in the fractional composition of fibers, their size and quality indicators. As a result, improving the quality of the wood-fiber mass provides an increasein thephysical and mechanical properties of wood-fiber boards under all other equal production conditions, which excludes the use of binding resins, and may indicate the possibilitof effective processing of logging waste.

Economic feasibility of obtaining wood phytomass through accelerated cultivation of pine wood on postagrogenic lands

The paper examines economic efficiency of obtaining wood biomass through accelerated cultivation of pine on postagrogenic lands of the Leningrad Region of Northwest Russia. In experimental pine plantations, we selected model trees and calculated the stem wood biomass of 11-year old stands with different stem densities. Assessments of the economic efficiency of the production of wood chips from pine wood grown on postagrogenic lands were based on a set of machines and mechanisms, consumables and wages. A break-even point was determined for the production of wood chips in plantations with different stem densities. In the variant with a stand density of 2900 trees per hectare, it is possible to make a profit, because a break-even point was obtained for the investments made. Pine stands of such density can be taken as a prototype, when creating and growing short rotation plantations. Based on the results of the study, it is possible to predict a further increase in pine wood biomass in a plantation on post-agrogenic soils. On postagrogenic lands, marketable wood pulp can be obtained within a short period of time; thus such lands will be involved in an economic turnover.

Process optimization and performance evaluation of a downdraft gasifier for energy generation from wood biomass

In recent time, due to the increasing demand for energy and the need to address environment-related issues, a great deal of focus has been given to alternative sources of energy, which are green, sustainable and safe. This work considers the process optimization and performance evaluation of a downdraft gasifier, suitable for energy generation using wood biomass. The assessment of the performance of the downdraft gasifier was based on the amount of output energy generated as well as the emission characteristics of the output. The Response Surface Methodology (RSM) was employed for the determination of the optimum range of the process parameters that will yield the optimum conversion of the biomass to energy. The optimum process parameters that produced the highest rate of conversion of biomass to energy (2.55 Nm3/kg) during the physical experiments were: temperature (1000 °C), particle size (6.0 mm) and residence time (35 min). The produced gas indicated an appreciable generation of methane gas (10.04 % vol.), but with a significant amount of CO (19.20 % vol.) and CO2 (22.68 % vol.). From the numerical results obtained, the gas yield was observed to increase from 1.86908 Nm3/kg to 2.40324 Nm3/kg as the temperature increased from 800 °C to 1200 °C. The obtained results indicate the feasibility for the production of combustible gases from the developed system using wood chips. It is envisaged that the findings of this work will assist in the development of an alternative and renewable energy source in an effort to meet the growing energy requirements.