Energy Production from Logging Residues of Eucalyptus in Brazil
Main Author: Renata Aguayo, Revised by: Sheikh Md Mohasin
Description of the Product or Technology:
Brazil is one of the most important countries when we talk about forest and its related products. From 7.84 million hectares of trees planted in Brazil in 2016, 34% belong to companies in the pulp and paper industry, being Eucalyptus the most planted specie, more than 70% of the total. In 2017 the Brazilian total volume of exported pulp was around 14 million tons, being Europe and USA the main markets. Brazil hosts the biggest pulp and paper companies in the world and these industries play an important role in the use of biomass for generating energy.
Many industrial processes, including the production of pulp and paper demand thermal (vapor) and electrical energy. To decrease the production costs and increase productivity of some pulp and paper companies start to co generate energy by using biomass. The mostly common resource of biomass used by these industries are the eucalyptus logging residues left in the field after the harvesting of logs for pulp production. This activity demands a good management considering the high costs for transport and logistics and it needs to be done in scale, in order to make this practice more competitive.
The process of using the logging residues is basic done after the harvesting, where the biomass (branches, stumps, leaves, tops) are taken from the field and transported to the chipping trucks (FIGURE 1). After this process, the wood chips are used in boilers to produce energy. Basically, the technologies for biomass conversion into thermal energy and/or electricity include the direct combustion, gasification and pyrolysis (CRAIG et al., 1998). Pulp companies that generate heat for their own process use mostly the direct combustion.
FIGURE 1: Flow diagram of the process of preparation and use of wood, the destination of the bark / forest residues and the flow of steam generation and electric energy.
Description of The market:
In Brazil the majority of biomass based primary energy are consumed by the industrial sector, that englobes food, beverages, paper and pulp, iron and steel industries. According to IBA (2017), the planted tree industry is responsible for generating most of the energy consumed in its production processes. In 2016, there was a 3.7% increase in energy production compared to the previous year; 67.5 million gigajoules (GJ) were generated, 69% of the 98.3 million GJ consumed by this industry. Besides generating energy for their own needs, more modern pulp mills generate surplus power for sale. Around 13.9 GJ were sold back to the public grid.
FIGURE 2: Energy Balance in the sector (2016).
The companies in the sector almost exclusively use by-products of their own processes to generate thermal and electrical energy. Black liquor from pulp production and forestry biomass represent 62.5% and 17.4% of all energy produced, respectively (FIGURE 3).
FIGURE 3: Energy Sources used by the Forest Sector.
Description of The policy Measures:
In 2002, the government created the PROINFA (Programa de Incentivo às Fontes Alternativas de energia elétrica, in Portuguese), which is a set of subsidies to encourage the expansion of small scale hydro power plants, wind energy and biomass to produce electricity. The first phase of the program aims to introduce 3300 MW of renewable energy in the national grid, by acquisition of electricity by the state owned utility ELETROBRAS in contracts for 20 years. The costs of electricity from this program (higher than the normal costs of electricity negotiated at the public electricity auctions) are shared out by the consumers (Vieira, 2011).
When compared to Agriculture, the Forest sector in Brazil does not receive as much incentives from the government. However, some programs have being implemented in order to support the forestry sector development, such as :
- Pronaf Florestal (Forestry Program for Familiar Agriculture Support)
- Prop flora
All these programs are supported by BNDES - The Brazilian Developing Bank.
The Brazilian pulp and paper companies receive support from BNDES when they ask for subsidies to expand their industries plants and related activities. There is no specific subsidy for generation of energy from biomass, at least not until this report.
Evaluation of The Effect of The Measure:
Co-generation of energy from logging residues in pulp and paper companies are becoming a common practice in Brazilian industries. This activity helps the companies to be more sustainable and to improve its revenues. However, considering the high costs of transportation and logistics, more studies and research to improve this activity need to be done. Moreover, other forest by products have potential to co generate heat as black liquor and charcoal. More incentives and subsidies from the government are essential for the development of this practice and consequently more adherence from other industry sectors.
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INDÚSTRIA BRASILEIRA DE ÁRVORES (IBÁ). Relatório Técnico 2017. São Paulo, 2017.
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VIEIRA, D., Policies to Encourage the Sustainable Development of Brazilian Electricity System with Distributed Generation, University of Cambridge, August 2011.