A technical and socioeconomic approach to estimate forest residues as a feedstock for bioenergy in northern Mexico

Background: Forest residues can be a feasible alternative for converting energy into fuels, electricity, or heat.Compared to other second-generation bioenergy sources, they do not compete for food, are relatively cheap,abundant in forest-rich areas, and more importantly their energy balance is close to zero. Biomass estimations can help design energy strategies to reduce fossil fuels dependency. Because of the land property distribution in Mexico,biomass estimations should consider not only the physical availability, but also the willingness of landowners to extract such raw materials.Methods: This study presents a methodological approach for evaluating the potential use of forest residues as a feedstock to generate bioenergy in northern Mexico. Remote sensing and field forest inventory were used to estimate the quantity and distribution of forest residues. In addition, a discrete choice analysis evaluated landowners’ preferences towards bioenergy development, including the most important factors that influence their willingness to extract their products and the expected price.Results and conclusions: Considering both physical and socio-economic aspects, results showed that about59,000 metric tons per year could be available in the study area. The vast majority of landowners surveyed are willing to extract forest residues, as long as they are presented with extraction plans with the highest income. However, many showed concerns about the environmental impacts this activity can have on soils,plants, and fauna. These results can help evaluate the potential of these resources for bioenergy development.

An Assessment of the Potential Use of Forest Residues for the Production of Bio-Oils in the Urban-Rural Interface of Louisiana

Louisiana is endowed with forest resources. Forest wastes generated after thinning, land clearing, and logging operations, such as wood debris, tree trimmings, barks, sawdust, wood chips, and black liquor, among others, can serve as potential fuels for energy production in Louisiana. This paper aims to evaluate the potential annual volumes of forest wastes established on detailed and existing data on the forest structure in the rural-urban interface of Louisiana. It also demonstrates the state’s prospects of utilizing forest wastes to produce bio-oils. The data specific to the study was deduced from secondary data sources to obtain the annual average total residue production in Louisiana and estimate the number of logging residues available for procurement for bioenergy production. The total biomass production per year was modeled versus years by polynomial regression curve fitting using Microsoft Excel. Results of the model show that the cumulative annual total biomass production for 2025 and 2030 in Louisiana is projected to be 80000000 Bone Dry Ton (BDT) and 16000000 (BDT) respectively. The findings of the study depict that Louisiana has a massive biomass supply from forest wastes for bioenergy production. Thus, the potential for Louisiana to become an influential player in the production of bio-based products from forest residues is evident. The author recommends that future research can use Geographic Information Systems (GIS) to create maps displaying the potential locations and utilization centers of forest wastes for bioenergy production in the state.

Forest Biomass Availability Analysis and Large-Scale Supply Options

Finnish forest companies aim to produce biodiesel based on the Fischer-Tropsch process from forest residues. This study presents method to evaluate biomass availability and supply costs to the selected biorefinery site. Forest-owners’ willingness to sell, buyers’ market share, and regional competition were taken into account when biomass availability was evaluated. Supply logistics was based either on direct truck transportation deliveries from forest or on railway/waterway transportation via regional terminals. The large biomass need of a biorefinery demanded both of these supply structures, since the procurement area was larger than the traditional supply area used for CHP plants in Finland. The average supply cost was 17 €/MWh for an annual supply of 2 TWh of forest biomass. Truck transportation of chips made from logging residues covered 70% of the total volume, since direct forest chip deliveries from forest were the most competitive supply solution in terms of direct supply costs. The better supply security and lower vehicle capacity needs are issues that would favour also terminal logistics with other raw-material sources in practical operations. One finding was that the larger the biomass need, the less the variation in biomass availability and supply costs, since almost the whole country will serve as a potential supply area. Biomass import possibilities were not considered in this study.

A Novel Approach to Ethanol Fuel Production using Rotary Collection of Forest Debris

In this article, the authors propose the production of ethanol from cellulose as an alternative to oil. Cellulosic-ethanol will reduce greenhouse gas emissions, and provide a means to prevent forest fires. This liquid dense fuel was selected because it： （1） easily transported and dispensed as a fuel; （2） can be handled by the existing fuel distribution infrastructure; and （3） unlike its commercial competitor, Me-OH （Methanol）, Et-OH （Ethanol）, is edible, thus being biodegradable and nontoxic. Forest residue ethanol is cheaper to produce and more environmentally friendly than other forms of ethanol fuel. Furthermore, forests would have less available ground fuel for fires. The potential decline of forest fires would then reduce the carbon footprint attributed directly to forest fires. In combination with ethanol fuel combustion, carbon emissions can be reduced by more than 70% compared to gasoline combustion. We used GREET （Greenhouse gases, Regulated Emissions, and Energy use in Transportation） software to assess the life cycles of different fuel pathways. In conclusion, cellulosic ethanol fuel is clearly an answer to decrease dependency on current oil imports and prevent forest fires.

Monitoring of Residual Forest Ecosystems Dynamics in the Mono Biosphere Reserve (Southeast Togo)

The forest ecosystems of the Lacs 2 commune (South-East, Togo) are undergoing severe degradation, which has not yet been documented. This study is carried out in order to assess and quantify the spatio-temporal dynamics of residual forests and to identify the determinants of deforestation in South East Togo. The methodological approach is based on the use of historical aerial photographs from 1976 and drone images from 2019 in addition to field investigations. Several spatial structure indices were also calculated in order to quantify the fragmentation of classes and of the forest landscape. The results show that the forest landscape is changing. The classes of forests, plantations and palm groves show an annual rate of decline of 7.5%, 0.8% and 9.4% respectively while the classes of savannahs, agglomerations, surface water and swamps increased by 16.4%, 0.4%, 0.7% and 0.1%. The results also reveal a high fragmentation within the forest, plantation, surface water and swamp class and moderate fragmentation for the savannah and palm trees classes. At the landscape level, the savannah class is dominant by more than 70%, thus making the landscape little diversified from an ecological point of view. The main driver of deforestation in the study area remains shifting slash-and-burn agriculture. It is accentuated by the establishment of perennial oil palm crops, which has influenced the annual deforestation rate by 0.72%.

A soil quality index for subtropical sandy soils under different Eucalyptus harvest residue managements

Eucalyptus harvest residues are attractive energy production resources for the forestry industry.However,their removal can have adverse impacts on soil quality and forest productivity,especially in sandy soils.In this study,we assessed the effects of Eucalyptus harvest residue managements with variable intensity on forest productivity and on physical,chemical,and biological indicators of the soil quality.The experiment was conducted in a Quartzipsamment(33 g kg-1clay)planted with Eucalyptus saligna in Barra do Ribeiro in southern Brazil.Before the Eucalyptus was planted,residues from the previous rotation were subjected to five different management treatments:(1)FRM,in which all forest residues(bark,branches,leaves,and litter)were allowed to remain on the soil and only trunk wood was removed;(2)FRMB,in which was identical to FRM except that bark was also removed;(3)FRMBr,in which only trunk wood and branches were removed;(4)FRR,which involved removing all types of residues(bark,branches,leaves,and litter);and,(5)FRRs,in which all forest residues from the previous rotation were removed,and leaves and branches from the new plantation were prevented from falling onto the soil surface using a shade net.Six years after planting,soil samples were collected at four different depths(0-2.5,2.5-5,5-10,and 10-20 cm)to determine 17 soil chemical,physical,and biological indicators.The results were combined into a soil quality index(SQI)using the principal component analysis approach.The SQI reduced by 30%,in the 0-20 cm layer,due to removal of harvest residues from the previous rotation,and collection of litter before it falls on the ground.The main drivers of SQI reduction were the principal components associated with soil organic matter and biological activity.Furthermore,the SQI was positively linearly related to tree height at P<0.01 and to tree diameter at breast height at P=0.07.The adverse impact on soil quality and forest productivity in our study indicates that removal of Eucalyptus harvest residues from sandy soils should be avoided.

Fire alters the availability of soil nutrients and accelerates growth of Eucalyptus grandis in Zambia

Fire has been used to prepare land during tree plantation establishment for many years but uncertainty about how ecosystems respond to prescribed burning makes it difficult to predict the effects of fire on soil nutrients.The aim of this study was to determine the effect of burning accumulated forest residues(slash)on soil chemical properties and how trees respond.We analyzed 40 burned and unburned sites and compared growth of Eucalyptus grandis W.Hill ex Maiden between sites.Soil pH increased by 39%after fire,suggesting reduced soil acidity and increased liming.Total nitrogen increased by 100%;other nutrients(Ca^2+,Mg^2+and K^+)also increased.Increase in nutrients had a significant effect on the growth of E.grandis;larger and taller trees were associated more with burned than unburned sites.This study provides evidence that burning accumulated slash during land preparation prior to plantation establishment alters soil nutrient status and enhances the growth of E.grandis.

Potential of using forest residue to offset coal use in co-fired coal power plants in the eastern United States

The global transition from fossil fuel-based energy sources to renewable energy sources will be most effective,for at least the near future,by utilizing local resources and existing infrastructure.In many areas of the eastern United States,forest residue is abundant and can be used in existing facilities to supplement coal in coal-fired power plants.Thus forest residue has potential as a renewable energy source that could be effectively utilized in the near future.This study uses GIS to estimate the potential quantity of forest residue available for use in coal-fired power plants in the eastern United States.Transportation costs limit the distance over which it is feasible to transport forest residue to the power plants and these costs may fluctuate depending on economic conditions.Thus,we consider three scenarios in our analysis assuming the maximum feasible transport distances to be 60,80,and 100 km.In the eastern U.S.,the total annual forest residue available to coal plants is approximately 29.4,40.2,and 48.2 million dry tons,respectively,for maximum transport distances of 60,80,and 100 km.Assuming an 80 km transport distance,forest residue has the potential to reduce coal consumption by 22.3 million tons per year.Under this scenario,greenhouse gas emissions would be reduced by almost 58.1 million tons per year,and NOx and SOx emissions would be reduced by 69.3 and 122.6 thousand tons respectively.This analysis suggests that by offsetting coal use,forest residue has the potential to substantially reduce power plant emissions.

Review in life cycle assessment of biomass conversion through pyrolysis-issues and recommendations

Biomass,widespread and carbon-neutral energy,can provide electric energy and replace fossil fuel-derived production.Pyrolysis is the main way of converting biomass to different bioenergy products with the consumption of material and energy,which will cause environmental impacts.To confirm the actual environmental impact of biomass conversion,life cycle assessment(LCA)is used for analyzing the process.Due to choosing different LCA methods,the results for the same thing in different reports will show obvious fluctuation.This review is devoted to providing recommendations on how to handle methodological issues when analyzing LCA study,by which researchers can better realize the similarities and differences in biomass conversion system.In this review,multiple clarifications and methodological recommendations on the four steps of the LCA process(including goal and scope definition,life cycle inventory,life cycle impact assessment,and interpretation)are provided.Furthermore,the LCA results are discussed systematically,in which the global warming potential gets extra attention.Meanwhile,different biomass feedstocks are divided into agricultural residues,forest residues,and microalgae carefully.Finally,the current challenges and future framework of biomass conversion are expounded in detail from the perspective of LCA.