مقاله انگلیسی رایگان در مورد بسته بندی پایدار از کربن فعال حاصل از زباله – الزویر 2018

Global greenhouse gases emissions have increased tremendously since 1950’s due to excessive burning of fossil fuel. The objective of this work is to develop and investigate packaging waste-derived activated carbon for carbon capture. Activated carbon was synthesized by carbonization of peanut-shaped packaging waste followed by chemical activation using KOH at a ratio of one to four. The activated carbon was characterized for it is textural properties using N2 adsorption at 77 K, and carbon dioxide adsorption isotherms at 273, 298 and 323 K. Non-Linear Density Functional Theory (NDLFT) was applied to carbon dioxide isotherm at 273 K to characterize narrow micropores and microporous structure of activated carbon. Field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) were used to investigate morphology and microstructure. TEM micrographs confirmed the existence of random micropores. We have also noticed that the textural properties were highly dependent on the concentration of the activating agent. Carbon dioxide adsorption on activated carbon materials has shown dependency on the volume of narrow micropores (less than 0.8 nm). The activated carbon materials have narrow micropore volume in a range of 0.155–0.292 cm3 , and BET surface area of 761–1383 m2 /g. Carbon activated with KOH ratio of three (WDC-03) has shown excellent CO2 uptake of 5.33 and 4.24 mmol/g at 273 and 298 K respectively. Moreover, it has also shown a high value for the isosteric heat of adsorption (29.8–14.3 KJ/mol) and selectivity of ∼16 over nitrogen.

Introduction

Among greenhouse gases, carbon dioxide (CO2) is the major contributor to global warming and climate change. CO2 comprised about 82% of the total US greenhouse gases (GHG) emissions in 2015 [1]. Its level has increased by 26.5% in the last 60 years. Without mitigation efforts to reduce emissions, the level is expected to increase by 200% by the end of this century; due to excessive burning of fossil fuels for power generation and other industrial processes [2]. Such practices will lead to catastrophic consequences including an increase in the earth’s temperature, an increase of sea level and flooding of coastal areas. To counteract the danger of the elevated carbon dioxide level in the atmosphere, several capture and storage technologies were studied as potential methods to reduce the amount released to the environment [3–6]. Several technologies have proven effectiveness for carbon dioxide absorption and adsorption. For instance, the ethanolamines are widely used in industry for selective absorption of CO2 from flue gases. This process is commonly used in industries which involve extensive use of carbon dioxide such as carbonated beverages industry [7]. However, this technology suffers from lack of sustainability and energy-intensive regeneration performed at temperature range of 100–120 °C. Furthermore, the corrosive nature of ethanolamines reduce the service life of process equipment [8,9]. Adsorption of CO2 through vacuum swing adsorption process is proposed to be an excellent alternative for conventional ethanolamine absorption technology. The major advantages of adsorption process are sustainability, wide range of available adsorbents and mild regeneration temperature. Various materials such as zeolite, silica, metal organic frameworks (MOF) and activated carbon have been used as adsorbents [10–12]. Recently, the demand for efficient and green materials for water wastewaters treatment has been increasing. This demand resulted in the development of efficient adsorbents from different materials, such as carbon nanotubes, metal oxides nanoparticles, and waste biomass. The adsorbents have shown excellent performance in the removal of pollutants such as hazardous dyes and heavy metals from wastewaters [13–28]. Activated carbon has several advantages over other adsorbents. It has excellent regeneration stability in the humid environment over zeolite and MOF, low cost, wide range available sources and activation processes for its production [29–32]. The most important feature of activated carbon is its easily tailorable properties by varying the type and amount activating agent and/ activation condition to produce the desirable textural properties such as surface area, pore volume, pore size, and pores size distribution [33–38].