This work was focused on understanding the pyrolysis of Typha latifolia. Kinetics, thermodynamics parameters and pyrolysis reaction mechanism were studied using thermogravimetric data. Based on activation energies and conversion points, two regions of pyrolysis were established. Region-I occurred between the conversion rate 0.1-0.4 with peak temperatures 538K, 555K, 556K at the heating rates of 10Kmin, 30Kmin, and 50Kmin, respectively. Similarly, the Region-II occurred between 0.4 and 0.8 with peak temperatures of 606K, 621K, 623K at same heating rates. The best model was diffusion mechanism in Region-I. In Region-II, the reaction order was shown to be 2nd and 3rd. The values of activation energy calculated using FWO and KAS methods (134-204kJmol) remained same in both regions reflecting that the best reaction mechanism was predicted. Kinetics and thermodynamic parameters including E, ΔH, ΔS, ΔG shown that T. latifolia biomass is a remarkable feedstock for bioenergy.

Wettability studies have been carried out on reservoir rocks using different techniques such as the Amott-Harvey method, the USBM method, and the contact angle method, all with limitations. In this study, the wettability is studied by discussing the surface charge using zeta potential measurements. The study relies on the finding that carbonated reservoir rocks, consisting of CaCO3mainly, are positively charged and their surface has the potential to adsorb significant quantities of anions. Moreover, heavy fractions such as asphaltenes are reported to remain afloat depending on dispersive forces present in the oil and its various fractions. Experiments are carried out on aqueous limestone suspension with the addition of crude oil. The experiment is repeated with the use of polymeric inhibitors, A and B. The zeta potential is found to alter depending on the sequence of polymeric inhibitor in oil/water addition. The inhibitor is found to adsorb on the limestone surface, with a net negative charge, causing repulsion between crude oil and the inhibitor and, hence, preventing the deposition of heavy fractions and particularly asphaltenes. This study gives a comprehensive insight on the mechanism of polymeric inhibitor interaction with the surface and the effect of wettability on its performance.

: The concept of energy hubs has grown in prominence as a part of future energy systems, driven by the spread of Distributed Energy Resources (DERs) and the inception of the smart grid. This paper systematically reviews 200 articles about energy hubs, published from 2007 to 2017, and summarizes them based on their modeling approach, planning and operation, economic and environmental considerations, and energy hub applications. The common applications of energy hubs are considered, such as distributed energy resources, the consideration of Plug-in Hybrid Electric Vehicles (PHEVs), and the hydrogen economy. This paper examines modeling approaches towards energy hubs, including storage and its network models; it mentions some of the optimization strategies used to tackle the efficient operation and control of energy hubs. The novelty of this work lies in the classification of research papers related to energy hubs, the development of a generic framework for modeling these multiple energy flow carriers with storage and network considerations, and the provision of solution techniques in line with energy hub optimization.

This study demonstrates a novel approach to examine the wettability tendency on calcium carbonate using zeta potential measurements. Different crude oil samples and asphaltenic solutions were studied and wettability profiles of limestone for these fluids were obtained using the zeta potential technique. In this study, suitable models (using Mathematica 8 and MS Excel) have been examined in order to fit the obtained data to the corresponding wettability profiles. A logistic model and a cycloid model were considered to represent the wettability profiles of limestone for crude oil and asphaltenic solutions, respectively. The R-squared value for the logistic function fit was found to be 0.99 with a standard deviation of 0.61 and a relative error of 1 × 10 −3 %. For the cycloid model, the best fit to the wettability profile for asphaltenic solutions, with different concentrations of 0.625, 1.25, and 2.5 wt %, were found to have an R-squared value ranging 0.86−0.98 with a maximum relative error of 1.33%.

No abstract

Wettability study using the ζ potential technique is a novel approach proposed for carbonate reservoir rocks. As opposed to other existing industrial and laboratory methods, such as the Amott−Harvey, United States Bureau of Mines (USBM), and contact angle methods, the ζ potential technique provides a complete wettability profile of limestone versus relative water/oil content in the presence of water for different oil samples. In addition, the study is extended for oil derivatives (i.e., asphaltenes and maltene). A case study was carried out to understand the effect of asphaltenic solutions on wettability of limestone rocks. From the obtained wettability profiles, it was found that different oil samples show the wettability transition, from water-wet to oil-wet. Moreover, the adsorption of maltenes was limited to the water-wet region whereas asphaltenes were found to be the main reason for heavy-fraction deposition.

Traditional wettability measurement practices, introduced as early as the late 1950s, are still perceived as reliable industrial methods for characterizing wettability. These techniques, in contrast to the contact angle method, provide indices that can quantitatively describe the degree of wetting state. Nevertheless, these approaches can determine the current state of wettability, subject to limitations. By employing the zeta potential measurements technique, a complete wettability profile is derived. In this chapter, the theory behind this technique is discussed. A case study is presented where the wettability of limestone rock is investigated, as crude oil and asphaltenic solutions of varying concentration are added to the limestonewater suspension. Findings of this study are discussed with the possible mechanism in effect when wettability alteration is observed.

No abstract