Primary Tar Research Articles

Study on coal pyrolysis characteristics by combining different pyrolysis reactors

The pyrolysis process of Shendong coal (SD) was first studied by combining the characteristics of thermal gravimetric (TG), pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) and Gray-King assay (G-K). The results show that the order of coke yields is G-K (76.35% (mass))>TG (73.11% (mass))>Py (70.03% (mass)). G-K coke yield caused by condensation reaction and secondary reaction accounts for 3.08% (mass) and 3.24% (mass), respectively. Compared with slow pyrolysis, fast pyrolysis has stronger fracture ability to coal molecules and can obtain more O-compounds, mono-ring aromatics and aliphatics. Especially, the content of phenolics increases significantly from 15.49% to 35.17%, but the content of multi-ring aromatics decreases from 23.13% to 2.36%. By comparing the compositions of Py primary tar and G-K final tar, it is found that secondary reactions occurred during G-K pyrolysis process include the cleavage of alkane and esters, condensation of mono-ring aromatics with low carbon alkene, ring opening, isomerization of tri-ring aromatics, hydrogenation of aromatics and acids.

Regulating phenol tar in pyrolysis of lignocellulosic biomass: Product characteristics and conversion mechanisms

The utilization of biomass pyrolysis is a crucial approach for sustainable development. This study used the typical biomass of pine (PI), rice husk (RH), and corn straw (ST) as feedstocks to evaluate the pyrolysis mechanisms, features and conversion mechanisms of the phenol tar product. The phenolic gaseous products were more trailing in ST, which mostly concentrated around 320–500 °C. Primary phenol tar is produced from lignin through the homolytic cleavage of β-O and α-O, and C-C bond breakage, primarily occurring before 550 °C. As the degree of aromatization increases, the oxygenates progressively deoxygenate, and the primary tar demethoxylates to form secondary tar as the temperature increases. The pyrolysis of cellulose produces H radicals, which aid the transformation of lignin into phenol tar. This study can provide a theoretical basis for biomass pyrolysis to select the appropriate process parameters to improve the quality of bio-oil and regulate phenol tar products.

LONG-TERM FOLLOW-UP, REOPERATIONS, AND PATIENT-REPORTED OUTCOMES FOLLOWING REVISION SURGERY FOR FAILED TOTAL ANKLE ARTHROPLASTIES

IntroductionPrimary ankle arthroplasty (TAR) is increasingly used to treat end-stage ankle arthritis. Reported revision rates of TAR vary from 8.5% to 11.1% at 9 years. Revision surgery remains technically challenging with options ranging from simple joint debridement to tibio-talar-calcaneal fusion. The efficacy of these procedures remains unclear and there is no consensus on optimal revision options.MethodsA retrospective cohort study was performed of all patients undergoing surgery for a failed primary TAR at the Nuffield Orthopaedic Centre (2004–2021). TAR failure was determined by clinical assessment, serial radiographs and CT scans. Primary outcome measures included type and time of index surgery post TAR. Secondary outcomes included frequency of re-operations, post-operative complications, patient reported outcomes and union rate (for revision arthrodesis procedures).Results70 failed TARs in 69 patients (35M:34F, mean 65.7 years, s.d.=11.6) underwent re-operation a mean of 6.24 years (range 1–30) post primary. In total, 107 operations were performed including revision fusion (n=50), revision arthroplasty (n=14), bearing exchange (n=9) and joint clearance (n=9). The overall revision fusion union rate was 73.5% over a mean of 12.5 months (s.d.=7.6). 16/23 (69.6%) Tibio-Talo-Calcaneal and 9/12 (75%) ankle fusions (previous subtalar/triple fusion) using a hindfoot nail united over a mean 11.4 months (s.d.=6.0) and 15 months (s.d.=9.48) respectively. Only 64% of ankle fusions using screws alone united (mean=10.6 months, s.d.=8.14). The average post-operative MOXFQ score was 28.3 (s.d.=19.3). 73% said the operation improved their function and would recommend it to a friend/family member.ConclusionDespite low post-operative MOXFQ scores, over 70% of patients were satisfied with re-operation for a failed TAR. Over 26% of all TAR revision fusions fail to unite with the highest non-union rates observed post ankle arthrodesis with screws alone (36.4%).

TRENDS IN TOTAL ANKLE ARTHROPLASTY IN SCOTLAND

IntroductionTotal ankle replacement (TAR) is performed for post-traumatic arthritis, inflammatory arthropathy, osteoarthritis and other indications. The Scottish Arthroplasty Project (SAP) began collection of data on TAR in 1997. In this study, using data from the SAP, we look at trends in the use and outcomes of TAR in Scotland.MethodsWe identified 499 patients from the SAP who underwent TAR between 1997 and 2015 with imaging available on the National Picture Archiving and Communication System (PACS). We identified, and looked at trends in, implant type over the following time periods: 1998–2005; 2006–2010 and 2011–2015. Age, gender, indication and outcomes for each time period were examined and also trends with implant type over time.ResultsThere were 499 primary TAR procedures with an overall incidence of 0.5/105 population per year. Eight different implants were identified with significant changes in the numbers of each type used over time. The peak incidence of TAR was in the 6th decade. The mean age of patients undergoing TAR from 59 years in 1997–2005, to 65 years in 2011–15 (p< 0.0001). The percentage of patients with inflammatory arthropathy was 52% in 1997–2005, compared with 10% in 2011–2015. Subsequent arthrodesis and infection rates appeared to be higher during the first time period. The female to male ratio also changed over time. The incidence of TAR increased overall during the study period (r= 0.9, p=< 0.0001). This may be due to a broadening range of indications and patient selection criteria, in turn due to increased surgeon experience and the evolution of implant design.ConclusionThis study examines a large number of TARs from an established arthroplasty registry. The rate of TAR has increased significantly in Scotland from 1997 to 2015. Indication and patient age has changed over time and this could potentially impact outcomes after ankle replacement.

SHORT-TERM OUTCOME OF COMPLEX REVISION TOTAL ANKLE ARTHROPLASTY

IntroductionTotal ankle arthroplasty (TAA) is an increasingly popular treatment option for patients with end-stage ankle arthritis. However, for most implant systems, failure rates of 10–20% have been reported within the first 10 years after primary TAA. Pain is the primary symptom that indicates failure of TAA but cause of it can be difficult to establish.MethodsAll patients who underwent a primary TAA at our center were included in the study. The clinical outcomes were studied for patients requiring a further revision procedure following primary TAA. The reasons for revision surgery and outcomes of surgery were analyzed using appropriate inferential statistical tests.ResultsBetween 2007 and 2018, 42 primary TAA required revisions in 40 patients. There were 25 men (59.5%) and 15 women (35.7%) with mean age of 57.5 years the time of primary TAA. All patients had undergone primary procedure at a mean duration of 3.5 years previously (range: 3 months to 10 years). Of the total revision procedures, 12/40 (30%) of revisions were carried out due to malalignment, 10/42 (23.8%) due to loosening of the implants or bone subsidence, 5/42 procedures (11.9%) following infection, 4/42 (9.5%) due to polyethylene migration, 1/42 (2.3%) due to fracture and 1/42 (2.3%) due to Charcot arthropathy. In 9/42 (21.4%) cases, imaging showed no objective reason for pain. 50% of patients who underwent revision TAA reported 78.5% satisfaction with results of surgery at 2 years follow up post-operatively.ConclusionMajor reasons for revising primary TAR at our centre are mal-alignment, implant loosening / bone subsidence and suspicion of infection and pain. In-spite of undergoing a complex revision surgery, patients report 78.5% satisfaction from outcomes of surgery.

The Use of the Catalysts Based on Coal Ash Microsphere and Chrysotile in the Thermal Destruction of Primary Coal Tar

In order to evaluate the possibility of using different catalysts prepared for the hydrogenation process of primary coal tar, the method of differential thermal analysis was used, which allows to determine the kinetic parameters of thermal destruction, such as the rate constant, activation energy, and pre-exponential multiplier. The effect of catalysts on characteristics of mass loss during heating of "Shubarkol Komir" JSC primary coal tar at a constant speed (20 K/min) in a nitrogen medium has been considered. Microsphere, NiO/microsphere, CoO/microsphere, chrysotile and NiCo/chrysotile have been taken as catalytic additives. In the presence of the catalysts, the rate of thermal destruction of primary coal tar increases in the following order: CoO/microsphere < NiO/microsphere < NiCo/chrysotile. While microsphere catalysts extend the range of thermal destruction, chrysotile catalysts lead to the rapid completion of the destruction process. This fact is characterized by the formation of bonds between catalytic additives and primary coal tar. It is important to determine such parameters that affect on the activation energy and macrokinetics of the thermal decomposition process for prediction of catalyst activity during hydrogenation of heavy hydrocarbon raw materials.

Experimental Study on Properties of Syngas, Tar, and Biochar Derived from Different Gasification Methods

Biomass gasification technology is a clean and renewable energy utilization approach. Understanding the evolution of gasification product properties is crucial to achieving carbon neutrality goals. A fixed-bed reactor is employed for the biomass gasification with CO2 in this study. Various methodologies have been conducted to characterize the syngas, tar, and biochar produced from the electric gasification (EG) and microwave gasification (MG) of oak and corn stalk samples at different temperatures. When gasifying the same biomass at the same temperature, the syngas yield of MG is generally 3–7% higher than that of EG, and the difference increases with decreasing temperature. The biochar yield of MG is 3–6% higher than that of EG. EG produces more tar at 600–800 °C. The yield of syngas increases as the gasification temperature rises from 600 to 1000 °C, but that of tar and biochar falls. The syngas mainly comprises H2, CH4, CO, and CO2. MG produces 8–15% higher CO content and 2.5–3.5% higher H2 content than EG. This is due to different heating mechanisms. The net calorific value of syngas increases with temperature, reaching a maximum of 11.61 MJ m−3 at 1000 °C for syngas from corn stalk MG. When the temperature rises from 600 to 1000 °C, more primary tars are converted into polycyclic aromatic hydrocarbons (PAHs). At 900 °C, corn stalk biochar from MG has a maximum specific total pore volume (0.62 cm3 g−1), surface area (525.87 m2 g−1), and average pore diameter (4.18 nm). The intensities of the characteristic peaks of biochar functional groups decrease gradually. The heating method has little effect on the types of functional groups.

The ceramic coated implant (CCI). Evolution total ankle replacements: a retrospective analysis of 40 ankles with 8 years follow-up.

Diminutive data is available on the outcome of several previously used total ankle replacement implants. The purpose of this study was to investigate the medium-term functional and radiological outcome and implant survival of the CCI Evolution implant. Consecutive series of 40 ankles operated in our hospital with primary TAR using the CCI Evolution implant in 2010-2013 were available for follow-up. The prospective clinical and radiographic data including the Kofoed score, subjective satisfaction and standard radiographs were collected preoperatively and at fixed time-points postoperatively. A CT was obtained in cases where osteolysis or loosening were suspected. The improvement of the Kofoed score and subjective satisfaction were statistically significant (p<0.0001). The implant survival was 97% (95% confidence interval (CI) 81%-100 %) at 5 years, and 81 % (95% confidence interval (CI) 60 %-92%) at 8 years. There were altogether 25 (64%) complications. Overall revision rate was 28% and failure rate 13%. The CCI implant outcome was not acceptable. The malposition of prosthetic components, subsidence, and peri-implant osteolysis were recorded often. Although the patient reported outcome measures improved, mostly due to positive changes in pain severity, overall revision and failure rates were high and comparable with previous findings of the CCI implant.

Partial oxidation of biomass gasification tar with oxygen transport membranes

Dual phase oxygen transport membranes were directly integrated into the producer gas stream of a low temperature circulating fluidized bed (LT-CFB) gasifier for partial oxidation of tar. Ce0.9Gd0.1O1.95–La0.6Sr0.4FeO3-d composite membranes were prepared by extrusion and dip-coating, co-sintered and infiltrated with electro-catalysts. These were investigated in two different set-ups: i) a membrane test rig, and ii) a partial oxidation testing unit connected to a biomass gasifier. The stability and performance of the membrane were tested in two different gas-streams; i) H2 and ii) producer gas. An oxygen flux of 1.5 Nml∙cm−2∙min−1 was measured in an air/H2 gradient at 850 °C through a 10 cm long membrane with a diameter of 10 mm, whereas a lower oxygen flux of 0.5 Nml∙cm−2∙min−1 was measured for the air/producer gas case. The producer gas contained ca. 2000 mg Nm−3 of primary tar. Analysis of the gas and the tar composition at the output of the membrane unit demonstrated that it contributed to the partial oxidation of the primary tar, resulting in a twofold increase of H2, CH4 and CO in the producer gas. This successful integration of oxygen transport membranes demonstrated that these membranes can reduce the tar content in producer gas from biomass gasifiers.

Получение и анализ первичной смолы пиролиза углей разного генетического типа по восстановленности

Combining the methods of thermal destruction and physicochemical analysis, the primary pyrolysis tar obtained from coals of different genetic restorability types (GRT) in the series Cdaf = 76,2-86,1 %) was analyzed. The pyrolysis carried out at a temperature of Tmax (derivatography, DTG-curve) showed that restored coals of the “b” type differ from coals of slightly reduced “a” type in an increased tar yield and have more intense absorption bands at 2900 cm-1 (Сal–Н bond) and at 810 cm-1 (Сar–Н bond). It has been established that Har/Hal relation in tar increases in the coal rank (Cdaf) and is higher for type “a” coals. Using the Brown-Ladner equation, the main structural parameters of the studied coals were calculated.

Study of flash pyrolysis and combustion of biomass powders using the Godbert-Greenwald furnace: An essential step to better understand organic dust explosions

An organic dust explosion is a heterogeneous system on a space and time scale. Predicting the parameters characteristic of its severity needs experimental and theoretical approaches to find the optimal compromise between consistency with reality and modelling time. A hybrid method is proposed to study flash pyrolysis and combustion of several organic powders (cellulose, wheat starch, oak wood, Douglas fir and olive pomace). A Godbert-Greenwald furnace was employed to perform the experiments to mimic the fundamental characteristics of a dust explosion: high particle heating rate, high reaction temperature and short residence times. At 973 K, the residence time is a critical parameter: the large particles of cellulosic compounds (wood, cellulose) do not reach their pyrolysis temperature and only fibres smaller than 20 or 30 µm are fully converted. As the particle size distribution of starch is smaller, heat transfer is not directly the limiting phenomenon but rather the strong tendency for powders to agglomerate during pyrolysis. At higher temperatures, secondary reactions of primary tars are evidenced, stressing the influence of the pyrolysis stage and leading to heterogeneous combustion. The composition of the pyrolysis gases as a function of the nature of the powder and the temperature was also determined. A lumped-kinetic model adapted to dust explosion was developed and validated for cellulose. The kinetics constants corresponding to levoglucosan to permanent gases and cellulose to char and water reactions are significantly different from those proposed by the literature, demonstrating that dust explosion kinetic parameters must be obtained under conditions consistent with such phenomenon.

Термическое разложение дистиллята каменноугольной смолы в присутствии нанопорошка железа

Impact of the nanosized iron powder on the process of thermal degradation of coal tar distillate was determined by the thermogravimetric analysis. Coal tar distillate was obtained by simple distillation up to 350°C of primary coal tar from the Shubarkol deposit. Iron powder was obtained by electrochemical reduction of iron from sulfate electrolytes at simultaneous impact of high-voltage electric discharge on cathodic zone. Scanning electron microscopy showed that iron powder consists of nanosized particles (30-124 nm) forming aggregates. X-ray diffraction analysis revealed the presence of α-Fe and FeO(OH) phases. The average crystallite size determination was made using Scherrer equation and amounted to 31.7 nm. Obtained iron powder was added to the coal tar distillate in amount of 1% of distillate weight and this mixture was subjected to thermal degradation at heating rate 5°C/min in an inert atmosphere. Processing of the data obtained was carried out using the model-fitting Coats-Redfern method. The values of activation energy were calculated from the linear approximation constructed as a result of processing thermoanalytical data. It was found that the addition of iron powder in amount of 1% to the coal tar distillate reduces the activation energy from 153.98 kJ/mol to 84.48 kJ/mol.

Biomass Behavior upon Fast Pyrolysis in Inert and in CO2-Rich Atmospheres: Role of Lignin, Hemicellulose and Cellulose Content

The present work focuses on the quality of char and primary tar produced from fast pyrolysis in N2 and CO2 of lignocellulosic biomasses: walnut shells (lignin-rich), straw (hemicellulose-rich) and pinewood (cellulose-rich). Heat treatments are carried out in a heated strip reactor (HSR) at 1573 and 2073 K for 3 s, with a heating rate of 104 K/s. The equipment allows for quenching the volatiles as soon as they are emitted. Chars are analyzed by thermogravimetric analysis in air. Results are compared with the products obtained from raw lignin, pure cellulose and pure hemicellulose. Cellulose and hemicellulose tars are dominated by anhydrous monosaccharides, which are scarce in straw tar and abundant in walnut shells tar. Polycyclic aromatic hydrocarbons PAHs are present in the primary products, in particular for walnut shells. The most reactive char is the one obtained from straw and the least reactive is the walnut shells char. Severe heat treatment and a CO2 atmosphere generate additional char components with higher and lower reactivity. The more reactive char component may arise from cross-linking reactions involving the monosaccharides (for which the result decreased in tar), whereas the less reactive component arises from thermal annealing and graphitization. Thus, the pyrolytic behavior of biomasses cannot be reconstructed with a mere addition of the lignin/cellulose/hemicellulose contribution, taking into account their content in the biomass.

Experimental and kinetic study on flash pyrolysis of biomass via on-line photoionization mass spectrometry

Experimental and kinetic study on flash pyrolysis of solid fuels is a challenge since its process usually occurs in a very few seconds. To do this successfully, a perfect combination of high heating rates, plug flow reactor, on-line sampling, real-time analysis and fast acquisition (e.g., < 300 ms/spectrum) is indispensable. In this work, a microfluidized-bed reactor (MFBR) was connected to the single photoionization time-of-flight mass spectrometer (SPI-TOFMS) to explore the kinetic process from flash pyrolysis of cellulose. The hydrodynamics of MFBR at different pyrolysis temperatures and with three model compounds were analyzed. The time-evolved profiles of primary tar from flash pyrolysis were recorded by SPI-TOFMS. The effect of experimental conditions (including pyrolysis temperature, transfer-line temperature and the type of carrier gas) on the kinetics of flash pyrolysis was systematically discussed. Besides, experimental measurements were also compared with kinetic modeling results, which shows a much better agreement between them than previous work. The obtained results prove that the MFBR combined with SPI-TOFMS is a potential and reliable method to experimentally study the flash pyrolysis of solid fuels.

A Kinetic Study of the Thermal Decomposition of Primary Coal Tar in the Presence of Catalysts with Nickel, Cobalt, and Iron Oxides Supported onto Microsilicate

A Kinetic Study of the Thermal Decomposition of Primary Coal Tar in the Presence of Catalysts with Nickel, Cobalt, and Iron Oxides Supported onto Microsilicate

Effect of Nickel Nanopowder on the Thermal Degradation of Coal Tar Distillate

Regularities of influence of nickel nanopowder on the thermal degradation of coal tar distillate were deter-mined using model-free Kissinger, Flynn-Wall-Ozawa and model-fitting Coats-Redfern methods. Coal tar distillate with a boiling point of &lt;350 °C was obtained by simple distillation of primary coal tar from the Shubarkol deposit. Nickel nanopowder was used as a catalyst and was added to coal tar distillate in a quantity of 1 % of the mass of the distillate and then the process of thermal degradation of coal tar distillate was con-ducted at heating rates 5, 10 and 20 °C/min in an inert gas medium. Nickel powder was obtained by high-voltage discharge impact on the dc electrolysis. X-ray diffraction (XRD) analysis showed that the obtained nickel powder has face-centered cubic structure and the average crystallite size calculated by the Scherrer equation was ~ 34 nm. Calculations of activation energy were performed via processing of thermogravimetric data. The Kissinger method showed that the activation energy value decreases from 145.19 kJ/mol to 43.65 kJ/mol, by the Flynn-Wall-Ozawa (FWO) method the value decreases from 152.82 kJ/mol to 51.65 kJ/mol, and by the Coats-Redfern method the value decreases from 143.38 kJ/mol to 52.64 kJ/mol. Ap-plicability of these methods is ensured by the high values of correlation coefficients.

Coronal Plane Deformity and Total Ankle Replacement: When to Stage with Cement Spacer Ankle Arthroplasty for Deformity Correction

Category:Ankle ArthritisIntroduction/Purpose:Degenerative ankle joint disease is a debilitating condition that causes significant pain, adversely affects function and quality of life. Though primary arthritis of the ankle can occur without deformity, frequently soft tissue imbalances or joint deformities complicate the clinical picture. Often, additional procedures are required to balance the foot and ankle during the index total ankle replacement procedure. When large deformities exist a staged approach to first, align the ankle joint to neutral as stage one and then implantation of the TAR as stage two can be deployed. This paper will further popularize the cement spacer staged TAR technique in correction of coronal deformities, share a clinical algorithm on approach, and depict a case series demonstrating its application.Methods:A case series was performed of 7 patients and 8 ankles, who underwent staged primary TAR utilizing a cement spacer to assist with deformity correction, between the years 2016-2019.Results:Patients' mean age 58.5 yrs., preoperative varus coronal plane deformity mean 19.1 degrees, preoperative valgus coronal plane mean 10.25 degrees. Mean time from stage 1 till 2 was 163.5, +-140.2 days. Stage 1 soft tissue procedures: Chrisman-Snook procedure with synthetic ligament graft, Brostrum-Gould with synthetic graft, Brostrum-Gould without graft, FDL transfer, and isolated medial release/peel. Osteotomies performed during stage one: Dwyer, MDCO, Cotton, and MDCO with medial malleolus osteotomy. Fusions performed during stage one consisted: Subtalar joint, talonavicular joint (TNJ), and STJ with 1st Metatarsophalangeal joint (MTPJ). Seven ankles were replaced with Cadence Total Ankle System (Integra), and one with INBONE II (Wright Medical Technology). Average follow-up time for included patients was 290.75 days (9.7 months). One revision was performed following index TAR procedure.Conclusion:This paper describes a cement wedge spacer staged total ankle arthroplasty technique for correction and stabilization of deforming forces at the ankle joint. While not all ankle deformities necessitate a staged approach, the complexity of the malalignment and the extent of tissue disruption needed to achieve a neutral ankle should be considered when correcting a given deformity with a staged or non-staged approach.

Effect of Packaging on Polyethylene Fractures, Implant Survivorship and Cyst Formation in Mobile Bearing Total Ankle Replacements

Category:Ankle Arthritis; AnkleIntroduction/Purpose:The Scandinavian Total Ankle Replacement (STAR) is the most widely used mobile bearing total ankle arthroplasty (TAA) in the US. The polyethylene component is ultrahigh molecular weight polyethylene and is designed to articulate with both the tibial and talar component. Initial data on the STAR in the US reported polyethylene fracture rates of greater than 10% as well as a concern for cyst formation due to osteolysis. The manufacturer changed the packaging to foil to prevent potential oxidation of the polyethylene, which could predispose the polyethylene to failure. The objective of the study was to evaluate a cohort of patients with STAR performed before and after converting to foil packaging to determine if there is a difference in polyethylene survivorship and cyst formation.Methods:All primary TARs performed by the senior author from 2010-2017 were reviewed. Patients with a minimum 48 month follow up were included in the study. The two groups were stratified by those performed prior to August 2014 (PRE) and those performed after August 2014 (POST). Preoperative and most recent postoperative alignment was determined on weight bearing radiographs. The outcomes included polyethylene fractures and cyst formation in the two groups. Cysts were defined as those measuring greater than 1cm2 on plain radiographs. Patients were recommended to have surgery if cyst volume was greater than 2cm2. Chi-squared tests were used to detect significant differences in the rate of cyst formation between the two groups. Paired t- tests were used to determine difference in preoperative versus postoperative alignment, follow up length, and polyethylene component thickness and patient age at time of procedure between the two groups.Results:The PRE group had 35 patients with an average follow up of 75 months (range 48-118). The POST group had 15 patients with average follow up 55 months (range 48-60). There was no difference in preoperative versus postoperative radiographic alignment between the groups (p>0.05). Cysts were present in 9 (26%) patients in the PRE group versus 4 patients (26%) in the POST group. Nine patients (26%) needed a second surgery due to cyst formation in the PRE group versus two (16%) in the POST group (p>0.05). Four patients (11%) had a fracture of the polyethylene in the PRE group with an average thickness of 6.7mm (range 6-9) and 77 months (range 68-84) versus zero in the POST group. The average time to polyethylene exchange for cyst(s) or polyethylene fracture was 58.3 months.Conclusion:This study suggests that changes in packaging to limit oxidation of the polyethylene from plastic to foil did not appear to represent a difference in periprosthetic cyst formation. However, there was a trend for additional surgery related to periprosthetic cysts and increased risk for polyethylene fracture in the PRE group. These results could suggest the potential for oxidation changes that alter the wear characteristics and fragility of the polyethylene component. Confounding factors could include postoperative time and component thickness. Further investigation and longer follow-up will be needed to further delineate oxygenation impacts on TAA polyethylene components.

Secondary Reactions of Primary Tar from Biomass Pyrolysis: Characterization of Heavy Products by FT-ICR MS

Secondary Reactions of Primary Tar from Biomass Pyrolysis: Characterization of Heavy Products by FT-ICR MS

Hydrogen-rich gas production from hydrochar derived from hydrothermal carbonization of PVC and alkali coal

This work targets to produce hydrogen-rich syngas by steam gasification of hydrochars obtained from co-hydrothermal carbonization (co-HTC) of polyvinyl chloride (PVC) and alkali coal. Hydrochar properties were assessed in terms of ultimate analysis, proximate analysis and the content of typical elements. The syngas, tar and char properties were investigated to explore the steam gasification performace of hydrochars. The co-HTC facilitated the destruction of the hydrophilic groups based on the O/C atomic ratio. The co-HTC increased the yield of H2 and CH4, while the CO2 yield was concurrently reduced. A relative high H2/CO ratio of around 1.65–3.96 was achieved when gasified hydrochar under the various temperature. This temperature was supposed to be an acceptable operational window for yielding H2-rich syngas. The catalytic effect of alkali and alkaline earth metals (AAEMs) on H2 production was weakened due to the AEEMs removal during the co-HTC, while the H2 production could be remedied by the PVC addition. The evolution of poly-aromatic hydrocarbons (PAHs) convinced the event of primary or secondary tars transformed into the tertiary tar. The rich pore structure of char indicated that char have good potential in adsorption, and the adsorption experiment of malachite green confirmed this point of view.These findings will offer comprehensive data on the coal upgrading and hydrochar gasification.