Bio-Oil Steam Reforming over a Mining Residue Functionalized with Ni as Catalyst: Ni-UGSO

Abstract

Bio-oil reforming is considered for syngas or H 2 production. In this work, we studied the steam reforming (SR) of two raw bio-oils without adding external steam, using a recently-developed catalyst, Ni-UGSO. Experiments were performed at temperature (T) = 750-850 • C and weight hourly space velocity (WHSV) = 1.7-7.1 g/g cat /h to assess C conversion (X C ) and product yields. The results show that, in all conditions and with both bio-oils tested, the catalyst is stable for the entire duration of the tests (~500 min) even when some C deposition occurred and that only at the highest WHSV tested there is a slight deactivation. In all tests, catalytic activity remained constant after a first, short, transient state, which corresponded to catalyst activation. The highest yields and conversions, with Y H 2 , Y CO and X C of 94%, 84% and 100%, respectively, were observed at temperatures above 800 • C and WHSV = 1.7 g/g cat /h. The amount of H 2 O in the bio-oils had a non-negligible effect on catalyst activity, impacting Y H 2 , Y CO and X C values. It was observed that, above a critical amount of H 2 O, the catalyst was not fully activated. However, higher H 2 O content led to the reduction of C deposits as well as lower Y H 2 and Y CO and, through the water-gas-shift reaction, to higher Y CO 2 (CO 2 selectivity). Fresh and spent catalysts were analyzed by physisorption (BET), X-ray diffraction, scanning electron microscopy and thermogravimetric analysis: the results reveal that, during the oils' SR reaction, the initial spinel (Ni-Fe-Mg-Al) structures decreased over time-on-stream (TOS), while metallic Ni, Fe and their alloy phases appeared. Although significant sintering was observed in used catalysts, especially at high H 2 O/C ratio, the catalyst's specific surface generally increased; the latter was attributed to the presence of nanometric metallic Ni and Ni-Fe alloy particles formed by reduction reactions. A small amount of C (4%) was formed at low H 2 O/C.

Modified fractional order PID structure for non‐integer model bioreactor control

“…where the total order of the numerator (m) is given by the total no of terms, that is, m ¼ P p i¼1 r i , and the order of the denominator (n) is determined by α. [65] In particular, system (38) is simplest if all the roots are identical.…”

“…[31][32][33][34][35] A comprehensive evaluation of the milestones, challenges, and opportunities for fractional order PID controllers in industrialization and their advantages is given in the work of Tepljakov et al [36] Irrespective of the slow adaptation, fractional order PID controllers' superiority in flexibility and robustness is well recognized and has shown more promising results than classical PID. [37][38][39][40][41][42][43] Differential evolution and soft computing-based algorithms have also been implemented to optimize the fractional order PID parameter to achieve satisfactory temperature control. [44][45][46] However, the drawback of soft computing techniques is that there is no guarantee that evolutionary algorithms will find the global optimum solution, and the stochastic nature of evolutionary algorithms can make it difficult to reproduce results.…”

Enhanced Ni-Al-Based Catalysts and Influence of Aromatic Hydrocarbon for Autothermal Reforming of Diesel Surrogate Fuel

“…In other words, hydrocarbon fuels react with air and steam, which generates hydrogen-rich gas. Compared with the conventional reforming methods, ATR as a potential reforming method exhibits higher energy efficiency and thermal stability [10][11][12][13][14][15][16][17]. The production technologies of green diesel have studied for combustion engines with remarkable properties and significantly lower emissions [18].…”