25th European Biomass Conference and Exhibition, 12-15 June 2017, Stockholm, Sweden
CHARACTERIZATION OF BRAZILIAN SUGARCANE BAGASSE AND SUGARCANE STRAW BASED ON EUROPEAN METHODOLOGIES TO EVALUATE THE POTENTIAL FOR ENERGY CONVERSION R. Moreiraa, R.C. Nevesb, C. C. Schmittc, M. Breunigc, P. C. Tambania, A. H. Ushimaa, A. Funkec, K. Rafeltc Institute for Technological Research (IPT), bBrazilian Bioethanol Science and Technoly (CTBE),cKarlsruhe Institute of Technology (KIT) – Institute of Catalysis Research and Technology. Prof. Almeida Prado Avenue 532, 05508-901 São Paulo, Brazil. +55 11 3767-4698,
[email protected]
a
ABSTRACT: Sugarcane (Saccharum spp.), one of the most important crops in the world, is used forethanol and sugar production at Brazilian sugarcane biorefineries. The residues, sugarcane bagasse (SCB) and sugarcane straw (SCS), known as Lignocellulosic Biomass (LCB) are usually used as fuel for Combined Heat and Power (CHP) in the First-Generation biorefineries. In order to select an alternative use for LCB, several factors must be taken into account, including chemical and physical characteristics, due totheir influence over the performance of the conversion technology chosen. The Institute of Research and Technology (IPT) has characterized biomasses following methodologies from European Norms (EN) and American Society for Testing and Materials (ASTM). The European Union, leader in renewable energy technologies, has developed special standards for solid biofuel in order to provide information that establishes quality concepts, for the reliability of results against consumers and producers of solid biofuels, for the exportation market and other advantages. Therefore, sugarcane bagasse and sugarcane straw were characterized following the European Norms in a joint project between IPT and KIT (Karlsruhe Institute of Technology). Additionally, both sugarcane residues were converted to organic liquids through liquefaction and fast pyrolysis and the conversion results are also presented. Keywords: sugarcane bagasse, characterization, lignocellulosic biomass, liquefaction, thermochemical conversion
1
content, moisture determination, volatile matter, fixed carbon) and ultimate analysis (C, H, N, O content) are the most important parameter to be investigated [8]. Currently, public and private institutions are seeking for new technologies regarding the biomass chain, in order to increase the process efficiency as well as its sustainability. With this purpose, the Fuels and Lubricants Laboratory (LCL) at the Institute for Technological Research (IPT) has adapted the analysis of physicochemical characterization of biomass using American standards (ASTM) that are applied to coal, coke and wood. The European Union has been developing methods for improving the characterization of interesting biomass for biorefineries to meet these specifications. The Karlsruhe Institute of Technology (KIT) has already developed its methodologies for the characterization of LCB based on current standards. Biomass characterization methodologies are playing a role for biomass conversion and any further assessments. The Brazilian Center for Research in Energy and Materials (CNPEM) is developing a biomass simulation platform called Virtual Sugarcane Biorefinery (VSB) at the Brazilian Bioethanol Science and Technology Laboratory (CTBE). This simulation platform can assess process alternatives and configurations within the biorefinery designs from a variety of biomasses. The VSB allows assessing different technologies considering technical, economic, environmental and social aspects. The advantages of using the VSB include [2]: optimization of processes; assessment of different biomasses within the biorefinery concept; assessment of different biorefinery concepts in view of their sustainability (economic, environmental and social impacts); assessment of the stage of development of new technologies; investigate new processes and designs. With this purpose, in this work is presented the SCB and SCS characterization according to the European Norms (EN) and the liquefaction experiments of a mixture of LCB from a Brazilian sugarcane biorefinery.
INTRODUCTION
The high productivity of sugarcane in Brazil generates a significant amount of agricultural waste in biorefineries [1]. The residual Lignocellulosic Biomass (LCB), sugarcane bagasse (SCB) and sugarcane straw (SCS), have the potential to be the most suitable feedstock for Second-Generation (2G) liquid fuels production [2]. Brazil is considered the largest sugarcane producer in the world [3]. The estimated average productivity and total sugarcane production in the 2016/2017 harvest is 76.3 t/ha and 684.8 million metric tons, respectively, representing an increase of 2.9% over the 2014/2015 harvest [4]. LCB can be used either for electricity generation or for chemical and fuel productions via different processes such as biochemical (SecondGeneration Ethanol) and thermochemical (SecondGeneration biofuels) pathways [5]. The LCB from sugarcane biorefinery can be used for downstream applications [6]. Liquefaction techniques like catalytic hydrogenolysis or fast pyrolysis, among other biomass conversion technologies, can produce liquid organic products with useful properties. The liquid organic phase from liquefaction via catalytic hydrogenolysis for instance, mainly consists of simple aromatic compounds like alkylated phenols and benzenes that can be interesting for chemical industry. Possible applications can also be bio-based liquid fuels or additives [7]. Therefore, the characterization of LCB is the primary important stepif further assessments are intended, such as techno-economic, social and sustainability analysis within any biorefinery concept such as 1G, 2G and the 1G-2G integration. Within this purpose, biomass properties vary and have different behaviors in thermal processes. To select a specific process of conversion, several factors must be taken into account, including chemical and physical characteristics of the feedstock, as the performance of the process can be directly affected. Among these characteristics calorific value, proximate analysis (ash
150
25th European Biomass Conference and Exhibition, 12-15 June 2017, Stockholm, Sweden
1:3. This moisture content equal to 10 wt% was set after thedrying process [10]. Therefore, LCB characterization could be presented as results. The experimental setup for liquefaction by catalytic hydrogenolysis was adapted fromBreunig[7]. In a first step the LCB was impregnated with the catalyst. X g of an aqueous iron(II) sulfate solution (20wt%) and Y g of an aqueous sodium hydroxide solution (20wt%) were mixed with 200 g of LCB and dried for 24 h at 105°C. 100 g of impregnated LCB and 200 g of tetralin were introduced into a 2000 mL stirred tank reactor. The setup was purged with nitrogen, pressurized to 100 bar with hydrogen and heated up to 440 ºC with a rate of 5 K min1 keeping the reaction temperature for 1 h. Afterwards,the reactor was cooled down to room temperature and a gas samplewas collected for gas chromatography analysis. Liquid and solid products were pumped out of the reactor and filtrated. The remainingresidues were washedwith ethyl acetate and filtrated. The ethyl acetate was removed from the liquid phase under vacuum and the liquid phases as well as the solid phases were reunited. The aqueous and the oily phase were then separated by a separation funnel. The fast pyrolysis conversion, aiming the liquid products, was performed atPython Process Development Unit (Python-PDU). Python-PDU located at the Institute of Catalysis Research and Technology (IKFT), Germany. The input capacity is of 10 kg h-1.This unit replicates the bioliq® pilot plant (approximately 500 kg h-1) considering smaller scale and is composed of 6 assemblies [10]: biomass feed, heat carrier loop, solid separation, organic condensate loop, aqueous condensate loop and product gas. Biochar is collect in solid separation while bio-oil is collected in both organic condensate and aqueous condensate loop. Further information concerning procedures and the unit can be found elsewhere[16].
The mass balance of catalytic liquefaction experiments from SCB and SCS and the mass balance of fast pyrolysis for LCB are presented to evaluate the behavior of liquid organic yields.
2
METHODOLOGY
Through the Technical Committee TC 335 "Solid Biofuels" several standards for biomass characterization were amended between 2009 and 2012. Currently, ISO/TC 238 is issuing new standards, replacing the existing European Norms (EN) with ISO standards. Biomass producers are now aware of these standards and some of them are seeking for biomass certification to make it possible to export this material to the European market. Table I shows the EN methodologies used in this work. Table I. EN Methodologies for biomass characterization. Method
EN Methodology
Ash content
DIN EN ISO 18122:2015 Solid biofuels Determination of ash content
Bulk density
DIN EN ISO 17828:2015 Solid biofuels Determination of bulk density
HHV*
BS EN 18125:2015 Solid biofuels Determination of calorific value
CHN** content
DIN EN ISO 16948:2015 - Solid biofuels Determination of total content of carbon, hydrogen and nitrogen
Chlorine content
DIN 51408-2:2009-06 Testing of mineral oil hydrocarbons – Determination of chlorine content - Part 2: Microcoulometric determination, oxidation method
-
Moisture content
DIN EN ISO 18134-2:2016 Solid biofuels Determination of moisture content - Oven dry method - Part 2: Total moisture Simplified method
Oxygen content
ISO 16993:2016 Solid biofuels - Conversion of analytical results from one basis to another
Sampling
DIN EN 18135:2015 Solid biofuels Sampling / DIN EN 14780:2015 Solid biofuel - Sample preparation.
Sulfur content
DIN ISO 15178:2001-02 Soil quality Determination of total sulfur by dry combustion.
3
RESULTS AND DISCUSSIONS
3.1 Sampling Preparation The samples were collected from two different sugarcane biorefineries in the state of São Paulo, Brazil, and characterized according to the European standards as presented in Table I. SCB was collected from Iracema’s biorefinery by IPT while SCB and SCS was collected by CTBEfrom Alta Mogiana S/A biorefinery. LCB was determined from the 1G-Anx-Op biorefinery composed only by CTBE samples. Both samplesSCB and SCS were dried until 10 wt% of moisture content, after collected in Brazil. The sample LCB was additionally dried at room temperature for 3 days at KIT. The sample SCS was chopped by Viking GE 260. All samples were milled to particle size
