Assessment of refuse-derived fuel production from a thin-layer landfill

Parichat Suknark, Sasidhorn Buddhawong*, Sirintornthep Towprayoon, Soydoa Vinitnantharat, Awassada Phongphiphat, Isaree Jirajariyavech and Komsilp Wangyao

<p style="text-align:justify;"><strong>Abstract:</strong> This study evaluates the refuse-derived fuel (RDF) production potential from a thin-layer landfill in Thailand. Unmanned
aerial vehicle (UAV) photogrammetry was used to estimate the waste volume. Electrical resistivity tomography (ERT) measurements
were performed to estimate the proportion of RDF in the waste pile using the relationship between resistivity and waste composition.
Then, an economic cost–benefit analysis was performed. Disposal zones C and D at Chanthaburi landfill were used as the study site.
The results showed that zones C and D's total waste volume and weight were 219,163 m³ and 170,947 tons, respectively. ERT results
imply that the potential of RDF production from plastic waste in zone C was between 27.01% and 35.57%, and between 29.96% and
55.64% in zone D. Thus, the spatial average of RDF production potential from both zones was approximately 30.97%. As a result,
the RDF produced during this study was approximately 55,666 tons. The economic cost–benefit analysis observed that the total
financial cost of construction and operation was 97,642,554 THB, while the benefits from selling RDF, soil-like material for waste
covering, and regaining the landfill volume was a totally 131,734,704 THB. The net present value was 50,754,800 THB, indicating
that the project was worthwhile.
</p><p><strong>Keywords:</strong> Electrical resistivity topography, landfill mining, refuse-derived fuel, thin-layer landfill.</p>

Enhancing antioxidative property of LDPE by additional ethanol organosolv lignin (EOL) extracted from eucalyptus

Nutchapon Horakul and Navadol Laosiripojana

<p style="text-align:justify;"><strong>Abstract:</strong> Lignin, a biopolymer which can be found in lignocellulosic materials, is the second most abundant from cellulose. Unlike
cellulosic compounds, lignin has an equivocal structure which is the limitation for the industrial applications. Since lignin has a great
antioxidative property, it has a capability to incorporate with the conventional plastics for the purpose of shelf-life extension as
packaging materials. In this work, Ethanol organosolv lignin (EOL), a sulfur-free lignin, was extracted from eucalyptus sawdust by using
ethanol as an organic solvent. The profiling of EOL was done via gel permeation chromatography (GPC), Scanning electron microscopy
(SEM), and Fourier transform infrared spectroscopy (FT-IR). EOL from eucalyptus was undergone the partial depolymerization via
mild ethanolysis (160, 200 °C for 1 h) to homogenize the lignin by lowering molecular weight (MW) and increasing radical
scavenging activity (RSA). Eucalyptus organosolv lignin (EL) has Mw of 1758 Da and 1.48 for Pd while the product at 160 °C
(ESL160) and at 200 °C (ESL200) has Mw of 1643 Da, 1.42 for Pd and Mw of 1613 Da, 1.41 for Pd. Lignin samples including EL,
ESL160, and ESL200 were then blended with LDPE and produced film, which was tested toward antioxidant activity. DPPH (2,2-
diphenyl-1-picrylhydrazyl) assay was used to evaluate the antioxidant activity of LDPE/lignin films and reported in the value of
%RSA. It was found that, at 1%wt of lignin in LDPE, %RSA of LDPE/EL, LDPE/ESL160, and LDPE/ESL200 were 17.83, 27.65,
and 27.54, respectively.
</p><p><strong>Keywords:</strong> Lignin, mild ethanolysis, depolymerization, LDPE, antioxidant activity.</p>