Pravin Kannan

ASPEN PLUS SIMULATION OF POLYETHYLENE GASIFICATION UNDER EQUILIBRIUM CONDITIONS

The gasification process of polyethylene (PE) was successfully modeled using a combination of various unit operation modules available in the Aspen Plus simulation package. The study presents significant insight into the effect of various process parameters on the polyethylene gasification process under equilibrium conditions that has not been reported elsewhere. The simulation tool was used to predict the product composition and temperature for varying cases of steam and airflow rates and pressure. Based on the simulation results, the behavior of the conversion process was characterized according to the combined and individual fractional efficiencies. Finally, the optimum conditions that would yield a maximum conversion for the PE gasification process have been identified and reported.

KOH-based porous carbon from date palm seed: preparation, characterization, and application to phenol adsorption

The date palm seed being one of the major forms of biomass produced from the date industry in UAE, its potential to be an appropriate precursor for the preparation of porous carbon utilizing KOH as an activating agent is assessed in the present work. The porous carbon is prepared at an activation temperature of 600 °C, impregnation ratio of 2, and activation duration of 1 hour, in an inert atmosphere using a conventional horizontal furnace. The resultant porous carbon has a Brunauer-Emmett-Teller surface area of 892 m(2)/g, pore volume of 0.45 cm(3)/g, and an average pore diameter of 1.97 nm. This porous carbon was used for adsorption studies at different initial concentrations (100-400 mg/l) and temperatures (30-50 °C). The adsorption isotherm parameters for the Langmuir and Freundlich models were determined using experimental adsorption data and it was found that both Langmuir and Freundlich isotherms described well the adsorption behavior of phenol on porous carbon. The mono layer adsorption capacity was observed to be 333 mg/g, which is highest for the reported date pam seed biomass-based porous carbon. From the data obtained, it was concluded that the removal of phenol from aqueous solution by porous carbon prepared from data palm seed is a low-cost process with an extremely high performance.

A Comparative Analysis of the Kinetic Experiments in Polyethylene Pyrolysis

A review of literature has been conducted to survey the kinetic data of low-density polyethylene (LDPE) pyrolysis. The review reveals large variations in the reported global kinetic parameters. The cause of variation has been identified to be the difference in the experimental techniques, including thermo gravimetric analysis (TGA) and non-TGA methods. Even within the nonisothermal TGA data, large variations have been observed at heating rate of 20 K/min, while the variations are insignificant at lower heating rate regimes (2-10 K/min), indicating the influence of heat/mass transfer resistance controlling the kinetics. Detailed analysis revealed that most of the current techniques are unable to capture all the relevant data necessary for estimating the kinetic parameters of the aforementioned process. The outcome of this review work thrusts the need for a better experimental technique to estimate the kinetic parameters of complex reactions, such as polymer pyrolysis.

Optimization of Waste Plastics Gasification Process Using Aspen-Plus

In this era of plastics dominated world, it remains a fact that there exists an everincreasing margin between the volume of waste plastics generated and the volume recycled [1]. Of the total plastic waste, recyclable thermoplastics like polyethylene, polystyrene, polypropylene and PVC account for nearly 78% of the total and the rest is composed of the non-recyclable thermosets like epoxy resins and polyurethane [2]. Typically, plastics waste management is practiced according to the following hierarchical order: Reduction, Reuse, Recycling, and finally energy recovery. Although reuse of plastics seems to be best option to reduce plastic wastes, it becomes unsuitable beyond certain cycles due to the degradation of plastic. Mechanical recycling of plastics involves significant costs related to collection and segregation, and is not recommended for food and pharmaceutical industries. While chemical recycling focuses on converting waste plastics into other gaseous or liquid chemicals that act as a feedstock for many petrochemical processes, energy recovery utilizes the stored calorific value of the plastics to generate heat energy to be used in various plant operations. Moreover, since plastic wastes always consist of a mixture of various polymeric substances, chemical recycling and energy recovery seems to be best possible solution, both in terms of economic and technological considerations.

Dynamic simulation of BTX adsorption in packed bed

ABSTRACT Rigorous design of commercial-scale packed beds accounting multicomponent adsorptions is mathematically complex, often resulting in adopting approximate simplified methods. Hence the present work attempts to simulate adsorption of BTX (benzene, toluene, m xylene) in a packed column of 10 m height and 3 m diameter for two adsorbents namely KIT-6 and mKIT-6 (surface modified) using Aspen Adsorption. The adsorption isotherm data of pure BTX components were generated for the adsorbent using a gas phase gravimetric analyzer. A comparative adsorption capacity indicates adsorption in the following order X > T > B for both the sorbents. m-xylene and toluene performed better on mKIT-6, as a result of which breakthrough and saturation time were higher. An increase in adsorbate feed concentration reduced the breakthrough and saturation time, proportional to the magnitude of increase. A significant reduction in the breakthrough time for benzene and toluene was observed due to competitive adsorption in the case of multicomponent adsorption as compared to pure component adsorption.

Polymer Recovery through Selective Dissolution of Co-mingled Post-Consumer Waste Plastics

It still remains a challenge to the recycling industry to develop an efficient and economical large-scale plastic waste recycling system, in spite of growing environmental concerns in waste disposal. Selective dissolution and precipitation (SDP) is a mechanical recycling technique that eliminates pre-sorting of mixed waste plastics and recycling polymer of high-grade quality. In this preliminary investigation, recycling of a comingled post-consumer waste plastic mixture of low-density polyethylene (LDPE), polystyrene (PS), high-density polyethylene (HDPE), and polyethylene terephthalate (PETE) using a lab-scale SDP setup was examined. A few experimental runs performed on the representative samples using Xylene/Toluene as solvents and acetone/2-propanol as anti-solvents demonstrated the sorting and recycling efficiency of this technique. FT-IR analysis of the reclaimed products revealed that the structural properties being very similar to virgin materials.

Effect of Temperature on Catalytic Steam Co-Gasification of Rubber Seed Shells and Plastic HDPE Residues

The catalytic co-gasification of rubber seed shell (RSS) and high density polyethylene (HDPE) mixture is investigated in a bench scale fixed bed system known as high throughput micro reactors (HTMR) system at different reactor temperature of 600 - 800 °C in order to study the effects on performance parameters such as gas and char yield, syngas yield and product gas composition. The operating temperature is selected based on the optimum conditions found from the previous study on the thermogravimetric analysis equipment coupled with mass spectrometer using these feedstock. The constant process variables used in the HTMR system are RSS particle size range of 0.100 - 0.150 mm, HDPE particle size range of 0.355 - 0.500 mm, and percentage of HDPE in the mixture of 20 weight%. The feeding rate of 2 g/h is carried out in the system.

Optimization Study of Catalytic Co-gasification of Rubber Seed Shell and High Density Polyethylene Waste for Hydrogen Production Using Response Surface Methodology

Experimental studies on the production of hydrogen (H2) gas from catalytic co-gasification of mixtures of plastic high density polyethylene (HDPE) derived from municipal solid waste (MSW) and biomass rubber seed shell (RSS) are conducted in a non-isothermal thermogravimetric analysis (TGA) equipment coupled with mass spectrometer (MS). A commercial nickel is selected as the catalyst in this process. The main objective of the present study is to assess the combined effect of the operating parameters such as temperature, HDPE particle size, RSS particle size, and percentage of plastics in the mixtures on the response variable i.e. production of H2 from the system. The steam generated by the superheater at temperature of 110 °C is injected at flowrate of 0.005 mL min−1 meanwhile argon gas is supplied at flowrate of 100 mL min−1 into the TGA-MS system. The steam to feedstock and catalyst to feedstock ratio of 1 and 0.1 are used respectively. A central composite design (CCD) based on response surface methodology (RSM) is used for the experimental design. The studies are carried out at temperature of 500–900 °C, HDPE particle size range of 0.125–0.625 mm, RSS particle size of 0.125–0.625 mm and percentage of HDPE in the mixture of 10–40 wt% on the response variable of H2 production. The optimum process parameter for maximum H2 production in the system is determined.