Experimental and Computational Demonstration of a Low-Temperature Waste to By-Product Conversion of U.S. Oil Shale Semi-Coke to a Flue Gas Sorbent

Abstract

The volatility of crude oil prices incentivizes the use of domestic alternative fossil fuel sources such as oil shale. For ex situ oil shale retorting to be economically and environmentally viable, we must convert the copious amounts of semi-coke waste to an environmentally benign, useable by-product. Using acid and acid + base treatments, we increased the surface area of the semi-coke samples from 15 m2/g (pyrolyzed semi-coke) to upwards of 150 m2/g for hydrochloric acid washed semi-coke. This enhancement in porosity and surface area is accomplished without high temperature treatment, which lowers the overall energy required for such a conversion. XRD analysis confirms that chemical treatments removed the majority of dolomite while retaining other carbonate minerals and maintaining carbon contents of approximately 10%, which is greater than many fly ashes that are commonly used as sorbent materials. SO2 gas adsorption isotherm analysis determined that a double HCl treatment of semi-coke produces sorbents for flue gas treatment with higher SO2 capacities than commonly used fly ash adsorbents. Computational fluid dynamics modeling indicates that the sorbent material could be used in a fixed bed reactor to efficiently remove SO2 from the gas stream.

Correlation of Mesophase Properties with Molecular Structures of Pitches from Different Sources

“…XRD was performed to determine the lamellar orientation of the coal pitches with the Cu–Kα source radiation. The microcrystal size L a , stack thickness L c , layer spacing d 002 , and layer number N are calculated by the Scherrer and Bragg formula according to the following formulas. − L a = 1.84 × λ β 100 × cos nobreak0em0.25em⁡ θ 100 L c = 0.89 × λ β 002 × cos nobreak0em0.25em⁡ θ 002 d 002 = λ 2 sin ( θ 002 ) N = L c d 002 + 1 where λ = 0.1542 nm, θ 100 is the diffraction angle of the peak (100), β 100 is the full width of half-maximum of the peak (100), θ 002 is the diffraction angle of the peak (002), and β 002 is the full width of half-maximum of the peak (002).…”

Co‐Carbonization of Medium‐ and Low‐Temperature Coal Tar Pitch and Coal‐Based Hydrogenated Diesel Oil Prepare Mesophase Pitch for Needle Coke Precursor

“…The crystal structure of carbon materials is usually studied by X-ray diffraction (XRD). [27,28] The D8 ADVANCE X-ray diffractometer of Bruker AXS was used to detect the microcrystalline structure of the needle coke. The test conditions were as follows: the light source was Cu Kα, the voltage was 40 kV, the current was 40 mA, the step length was 0.02 , the scan rate is 8 min À1 , and the scanning range is 5 -90 .…”

Influence of Raw Materials and Technological Factors on the Sorption Properties of Blast-Fuel Coke

“…Gold is also extracted from the eluates by cementation on electronegative metals. To increase the degree of gold recovery, it is important to find an effective and inexpensive sorbent [27][28][29][30][31][32][33][34][35][36][37]. In the research [36] adsorbent was obtained by activating the coke fraction with a size of 2-5 mm with superheated steam at 850 • C for 30 min.…”

“…Work [28][29][30][31][32][33][34][35][36][37][38] illustrates the results of using the method of low-temperature chemical treatment of shale semi-coke for its activation, which provides an increase in the surface area by 6-11 times compared to untreated material. Thus, using acid (HCl) and alkali (KOH) treatment, the surface area of semi-coke samples was increased from 15 m 2 /g (pyrolyzed semi-coke) to more than 150 m 2 /g after washing the samples with hydrochloric acid.…”