Agriculture, in a country like Ecuador, benefits greatly from different climatic zones, which allow a steady and diversified annual production. It is for this and many other reasons that 26% of the national territory is used for agriculture, and when crops are harvested, a large trail of residues is left1. In this way, agricultural production contributes to greenhouse gas (GHG) emissions that end up in the atmosphere due to the burning and decomposition of residues. It is estimated that this sector produces 160 million tCO2 per year, which represents 28% of all carbon emissions of the country2.
This scenario requires environmentally-friendly technologies to deal with the constant residue flow. At the same time, residues are considered an excellent source of activated carbon (AC); however, its extraction demands a proper method in terms of quality and quantity. Of the many methods of AC extraction, hydrothermal carbonization (HTC) presents itself as an environmentally-friendly technique because it is used for the revaluation of residual biomass, as well as organic waste, and the resulting solid carbon material has many properties for different applications3.
Goals
1
To determine the main crops that produce suitable residues for further transformation into activated carbon.
2
To explore the AC market and its portfolio of applications, as well as its different kinds according to their origin.
3
To assess the financial feasibility of the hydrothermal carbonization process for the extraction of activated carbon.
4
To examine the activated carbon-based material and its potential applications for energy production technology.
5
To compare the environmental impact of activated carbon synthesis by hydrothermal carbonization with other processes.
Hydrothermal Carbonization Process
(Adapted from Kruse, 20164)
Research Design
1
Stock evaluation of agricultural residues in Ecuador and main crop residue-producers, as well as the establishment of quality parameters into AC transformation.
2
AC demand and supply assessment, categorization of product by origin and applications, and cost projection comparison between HTC production and pyrolysis.
3
AC synthesis with a small-size HTC reactor and comparison of the obtained material with that obtained via pyrolysis.
4
To perform a life cycle assessment (LCA) to compare environmental impact categories between HTC and pyrolysis.
5
To research quality parameters of carbon material obtained through HTC for potential use as an energy storage material.
NOTE: Due to intellectual property reasons of the academic institutions and organizations involved in this project, this article is meant to be used for educational purposes only. Please contact us for more detailed information.
1 Smith, P., Martino, D., Cai, Z., Gwary D., et. al., 2008. Greenhouse gas mitigation in agriculture. Philosophical Transactions of the Royal Society B: Biological Sciences, 363(1492), pp. 789-795
2 MAE, 2014. Ministerio del Ambiente. Aprovechamiento Energético de Residuos Agropecuarios. Enfocado a la Mitigación del cambio climático, Ecuador, Quito. Boletín (4), pp. 3
3 Puccini, M., Stefanelli, E., Hiltz, M., SeWggiani, M., and Vitolo, S., 2017. Activated Carbon from Hydrochar Produced by Hydrothermal Carbonization of Wastes. Chemical Engineering Transactions, Vol. 57
4 Kruse, A., 2016. Sustainable Industrial Process. Thermochemical Biomass Conversion, Hydrothermal Carbonization. Notes of the Module Sustainable Industrial Process, University of Hohenheim.