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Corn wet distillers' fiber (corn fiber) is a byproduct of the corn-ethanol production process, with high potential as a precursor for activated carbon due to its moderate nitrogen content and availability. However, there has been limited investigation into activated carbons from the corn fiber. In this work, we produce activated carbons from the corn fiber using three procedures, including direct KOH activation, hydrothermal carbonization (HTC) followed by KOH activation, and FeCl3-catalyzed HTC followed by KOH activation. Catalytic HTC with FeCl3 was found to slightly increase the degree of carbonization relative to uncatalyzed HTC while also removing the nitrogen content at increasing concentrations and slightly increasing the porosity. The resulting activated carbon samples are then characterized by thermal gravimetric analysis, Fourier transform infrared spectroscopy, scanning electron microscopy, and nitrogen analysis. The two-step process resulted in activated carbon with substantially higher surface areas than the one-step process (1220 vs 789 m2/g), as well as much higher thermal stability and nitrogen content (up to 1.20%). The results show that the corn fiber has potential for activated carbon production, with the two-step HTC followed by the activation process producing more favorable material properties than direct activation.

Interest in hydrothermal carbonization (HTC) is increasing worldwide due to its outstanding capabilities. This study introduces a novel semi-continuous feeding system to feed the biomass slurry against the high pressure of an HTC reactor. As expected in a semi-continuous operation, the biomass would be instantaneously exposed to the desired pressure and temperature, instead of a gradual increase to the desired temperature. Higher degrees of carbonization, lower cellulose crystallinity, improved hexagonal graphene sheets, surface hydrophobic characteristics, and higher thermal stability were observed at elevated temperatures in products from semi-continuous HTC when compared with products from batch operation. Reaction pathways were proposed for both batch and semi-continuous operations on the basis of physical and chemical characterization results. For HTC at 260 °C, the proposed semi-continuous system showed approximately 3% higher carbon content in the obtained hydrochar and a 25-min reduction in required time to reach 260 °C. The promising conclusion of these results is that by introducing continuous systems in HTC, not only will the time of the process cycle decrease, it will also achieve higher degrees of carbonization.

Biomass for activated carbon production has had been gaining interest in a wide variety of applications such as water filtration, gas adsorption, and electrochemical devices as a renewable carbon source while meeting desired porosity, surface area, conductivity, and stability requirements. Activated carbon production has been extensively investigated, proving to provide high performance in applications including electrochemical devices. Hydrothermal carbonization (HTC) has shown potential as a pretreatment method for activated carbon production, especially when surface functionalization is desired. However, research into catalytic HTC is still limited. In this review, the processing methods used to convert biomass waste products into high value activated carbon are briefly reviewed, with a focus on recent progress in catalytic HTC as a pretreatment method to activated carbon. Areas of interest for catalytic HTC for activated carbon production are identified. Recent studies have found that the use of catalysts enhances the degree of carbonization, surface modification, and introduction of key heteroatoms significantly augmenting the performance of activated carbon. With further development of catalytic HTC technology, more competent carbon material for electrochemical devices can be produced cost-effectively and move towards meeting the ever-increasing demands of activated carbons for high-performance electrochemical devices.

Corn wet distillers’ fiber (corn fiber) is a byproduct of the corn-ethanol production process, with high potential as a precursor for activated carbon due to its moderate nitrogen content and availability. However, there has been limited investigation into activated carbons from the corn fiber. In this work, we produce activated carbons from the corn fiber using three procedures, including direct KOH activation, hydrothermal carbonization (HTC) followed by KOH activation, and FeCl3-catalyzed HTC followed by KOH activation. Catalytic HTC with FeCl3 was found to slightly increase the degree of carbonization relative to uncatalyzed HTC while also removing the nitrogen content at increasing concentrations and slightly increasing the porosity. The resulting activated carbon samples are then characterized by thermal gravimetric analysis, Fourier transform infrared spectroscopy, scanning electron microscopy, and nitrogen analysis. The two-step process resulted in activated carbon with substantially higher surface areas than the one-step process (1220 vs 789 m2/g), as well as much higher thermal stability and nitrogen content (up to 1.20%). The results show that the corn fiber has potential for activated carbon production, with the two-step HTC followed by the activation process producing more favorable material properties than direct activation.

Corn Wet Distillers' Fibre (Corn Fibre) and Corn Condensed Distillers' Solubles (CDS) are by-products of the corn-ethanol production process with limited investigation of their valorization potential available in the literature. In this work, we perform hydrothermal carbonization (HTC) on Corn Fibre and CDS at reaction temperatures ranging from 180 °C to 300 °C. The solid products were characterized by ultimate and proximate analysis, HHV, TGA, FT-IR, Py-GC-MS, and SEM. The liquid process water composition was characterized by GC-MS analysis, and the total organic carbon (TOC) was determined. The produced hydrochar had a higher heating value of up to 33.91 MJ/kg, and nitrogen content as high as 3.91% Nitrogen at 77.35% Carbon. The hydrochar had a much higher ratio of hydrogen to oxygen content than most hydrochars from biomass investigated in the literature. The process water for CDS had a high quantity of hydrocarbons and high liquid carbon yield, whereas the process water from Corn Fibre contains large quantities of hydroxymethylfurfural (HMF). These findings indicate that HTC of Corn Fibre and CDS may be a promising alternative pathway for producing valuable chemicals or high-quality hydrochar for fuel or higher value applications which can utilize nitrogen content, such as activated carbons.

Iron-based industries are one of the main contributors to greenhouse gas (GHG) emissions. Partial substitution of fossil carbon with renewable biocarbon (biomass) into the blast furnace (BF) process can be a sustainable approach to mitigating GHG emissions from the ironmaking process. However, the main barriers of using biomass for this purpose are the inherent high alkaline and phosphorous contents in ash, resulting in fouling, slagging, and scaling on the BF surface. Furthermore, the carbon content of the biomass is considerably lower than coal. To address these barriers, this research proposed an innovative approach of combining two thermochemical conversion methods, namely hydrothermal carbonization (HTC) and slow pyrolysis, for converting biomass into suitable biocarbon for the ironmaking process. Miscanthus, which is one of the most abundant herbaceous biomass sources, was first treated by HTC to obtain the lowest possible ash content mainly due to reduction in alkali matter and phosphorous contents, and then subjected to slow pyrolysis to increase the carbon content. Design expert 11 was used to plan the number of the required experiments and to find the optimal condition for HTC and pyrolysis steps. It was found that the biocarbon obtained from HTC at 199 °C for 28 min and consecutively pyrolyzed at 400 °C for 30 min showed similar properties to pulverized coal injection (PCI) which is currently used in BFs due to its low ash content (0.19%) and high carbon content (79.67%).

We discuss a systematic effect associated with measuring polarization with a continuously rotating half-wave plate. The effect was identified with the data from the E and B Experiment (EBEX), which was a balloon-borne instrument designed to measure the polarization of the CMB as well as that from Galactic dust. The data show polarization fraction larger than 10\% while less than 3\% were expected from instrumental polarization. We give evidence that the excess polarization is due to detector non-linearity in the presence of a continuously rotating HWP. The non-linearity couples intensity signals into polarization. We develop a map-based method to remove the excess polarization. Applying this method for the 150 (250) GHz bands data we find that 81\% (92\%) of the excess polarization was removed. Characterization and mitigation of this effect is important for future experiments aiming to measure the CMB B-modes with a continuously rotating HWP., 43 pages, 12 figures, submitted to the Astrophysical Journal

Introduction Current methods of determining applied forces in the hand rely on grip dynamometers or force-measurement gloves which are limited in their ability to isolate individual finger forces and interfere with the sense of touch. The objective of this study was to develop an improved force measurement system that could be used during various activities of daily living. Methods Custom-made strain gauge sensors were secured to the fingernail of four fingers and two middle phalanges and calibrated to measure hand forces in eight healthy individuals during five activities of daily living. Results These sensors were capable of measuring forces as small as 0.17 N and did not saturate at high force tasks around 15 N, which is within the envelope of forces experienced during daily life. Preliminary data demonstrate the ability of these tactile sensors to reliably distinguish which fingers/segments were used in various tasks. Conclusions Until now, there has been no method for real-time unobtrusive monitoring of force exposure during the tasks of daily life. The system used in this study provides a new type of low-cost wearable technology to monitor forces in the hands without interfering with the contact surface of the hand.

The E and B Experiment (EBEX) was a long-duration balloon-borne cosmic microwave background polarimeter that flew over Antarctica in 2013. We describe the experiment's optical system, receiver, and polarimetric approach, and report on their in-flight performance. EBEX had three frequency bands centered on 150, 250, and 410 GHz. To make efficient use of limited mass and space we designed a 115 cm$^{2}$sr high throughput optical system that had two ambient temperature mirrors and four anti-reflection coated polyethylene lenses per focal plane. All frequency bands shared the same optical train. Polarimetry was achieved with a continuously rotating achromatic half-wave plate (AHWP) that was levitated with a superconducting magnetic bearing (SMB). Rotation stability was 0.45 % over a period of 10 hours, and angular position accuracy was 0.01 degrees. This is the first use of a SMB in astrophysics. The measured modulation efficiency was above 90 % for all bands. To our knowledge the 109 % fractional bandwidth of the AHWP was the broadest implemented to date. The receiver that contained one lens and the AHWP at a temperature of 4 K, the polarizing grid and other lenses at 1 K, and the two focal planes at 0.25 K performed according to specifications giving focal plane temperature stability with fluctuation power spectrum that had $1/f$ knee at 2 mHz. EBEX was the first balloon-borne instrument to implement technologies characteristic of modern CMB polarimeters including high throughput optical systems, and large arrays of transition edge sensor bolometric detectors with mutiplexed readouts., Comment: 49 pages, 32 figures, submitted to The Astrophysical Journal Supplement