A Systematic Approach to Thermochemical Treatment of Municipal Household Solid Waste into Valuable Products: Analysis of Routes, Gravimetric Analysis, Pre-Treatment of Solid Mixtures, Thermochemical Processes, and Characterization of Bio-Oils and Bio-Adsorbents

Abstract

This work aims to investigate the effect of process temperature and catalyst content by pyrolysis and thermal catalytic cracking of (organic matter + paper) fraction from municipal household solid waste (MHSW) on the yields of reaction products (bio-oil, bio-char, H2O, and gas), acid value and chemical composition of bio-oils, and characterization of bio-chars, in laboratory scale. The collecting sectors of MHSW in the municipality of Belém-Pará-Brazil were chosen based on geographic and socio-economic database. The MHSW collected and transported to the segregation area. The gravimetric analysis of MHSW carried out and the fractions (Paper, Cardboard, Tetra Pack, Hard Plastic, Soft Plastic, Metal, Glass, Organic Matter, and Inert) separated. The selected organic matter and paper submitted to pre-treatment of crushing, drying, and sieving. The experiments carried out at 400, 450, and 475 °C and 1.0 atmosphere, and at 475 °C and 1.0 atmosphere, using 5.0, 10.0, and 15.0% (wt.) Ca(OH)2, in batch mode. The bio-oil characterized for acid value. The chemical functions present in bio-oil identified by FT-IR and the composition by GC-MS. The bio-char characterized by SEM, FT-IR and XRD. The variance in mass (wt.%) for organic fraction of municipal household solid waste, between 56.21 and 67.45% (wt.), lies with the interval of 56% (wt.) and 64% (wt.) of OFMHSW for middle and low income countries. The pyrolysis of MHSW fraction (organic matter + paper) show bio-oil yields between 2.63 and 9.41% (wt.), aqueous phase yields between 28.58 and 35.08% (wt.), solid phase yields between 35.29 and 45.75% (wt.), and gas yields between 16.54 and 26.72% (wt.). The bio-oil yield increases with pyrolysis temperature. For the catalytic cracking, the bio-oil and gas yields increase slightly with CaO content, while that of bio-char decreases, and the H2O phase remains constant. The GC-MS of liquid reaction products identified the presence of hydrocarbons (alkanes, alkenes, alkynes, cycloalkanes, and aromatics) and oxygenates (carboxylic acids, ketones, esters, alcohols, phenols, and aldehydes), as well as compounds containing nitrogen, including amides and amines. The acidity of bio-oil decreases with increasing process temperature and with aid Ca(OH)2 as catalyst. The concentration of hydrocarbons in bio-oil increases with increasing Ca(OH)2-to-MHSW fraction ratio due to the catalytic deoxygenation of fatty acids molecules, by means of de-carboxylation/de-carbonylation, producing aliphatic and aromatic hydrocarbons.

Thermochemical Transformation of Municipal Household Solid Waste Fractions into Bio-Oils and Bio-Adsorbents

“…The methodology applied in the research is illustrated in Figure 1, which summarizes well the methodology of the process, described as a logical sequence of ideas, methods and procedures for sustainable disposal and thermal treatment of Municipal Solid Waste (MSW) to produce biochar and bio-oil from pyrolysis and catalytic pyrolysis on a laboratory scale. This work uses a methodology similar to Assunção et al [37], in which the definition of the study area was the municipality of Belém/Pará, in which the provision of solid waste collection services is carried out by the company TERRAPLENA LTDA is responsible for Lot 1, as presented in the Municipal Basic Sanitation Plan of Belém [38]. It is crucial to understand the specific context of basic sanitation conditions in this region, 21 neighborhoods are included in this area that cover a significant part of the city and have the presence of 37 itineraries (itineraries), indicating the extent of the coverage of the company TERRAPLENA LTDA in the provision of services related to basic sanitation, such as solid waste collection, water and sewage treatment, among others.…”

“…The reactor was inserted into a cylindrical furnace with a collar-type ceramic resistance, with a power of 800 W, which was connected to the digital temperature and heating rate controller (THERMA, Model TH90DP202-000), which had a K-type temperature sensor (Ecil, Model: QK. 2), as described in detail else-where Assunção et al [37]; De Castro et al [44]. Figures 3 and 4 exemplify the description of the Pyrolysis laboratory unit.…”

“…The calculated sample mass is the representative quantity required to perform an accurate and reliable analysis of the gravimetric composition of the waste. The choice of significance level, confidence level and margin of error reflects the concern with the statistical validity of the results Assunção et al [37] and Pereira et al [39].…”

“…The process begins with measuring the total mass of waste, which is crucial to guide the gravimetry process and ensure the representativeness of the sample. The reference to the work of Assunção et al [37] suggests the use of a specific methodology or protocol for gravimetric characterization.…”

Improving the Antioxidant Activity, Yield and Hydrocarbon Content of Bio-Oil from Açaí Seeds Pyrolysis by Chemical Activa-Tion: Effect of Temperature and Molarity

“…An overall mass balance was done in order to calculate the quantity of gas formed. Basically, the weight of feed, bio-oil, aqueous phase and coke formed are recorded and a global integral mass balance calculation yields the quantity of gas formed by difference [54][55]. A differential mass balance of the considered system is described by the following equation ( 1):…”