Straw pyrolysis for use in electricity storage installations.

A concept has been proposed for an installation designed to store excess electricity periodically occurring on the grid. Excess electricity will be used for straw pyrolysis. The main pyrolysis product, gas, will be used to generate electricity using a combustion generator to feed back power into the grid during periods of shortage. The resulting biochar from the pyrolysis can be introduced into the soil to improve soil quality and play a significant role in carbon sequestration. The system uses an electrically heated reactor with a screw conveyor. To preliminarily assess the feasibility of this system, experiments were carried out using wheat straw at temperatures of 300, 400, 500, 600, and 700 °C for the pyrolysis reactor. The resulting gas-to-feedstock mass ratio ranged from 29.04 % at 300 °C to 52.7 % at 700 °C reactor temperature, the biochar mass yield ratio to feedstock varied from 39.41 % to 27.36 % (at 700 °C), and the pyrolysis liquid ranged from 31.55 % to 27.36 % (at 700 °C). The pyrolytic liquid contained a high water content relative to its mass, reaching up to 95.2 % at 700 °C, rendering it less suitable as an energy feedstock. At a reactor temperature of 700 °C, the energy value of the gas produced from the feedstock was twice that of the electricity used for the pyrolysis process. These results suggest the feasibility and operation of the proposed installation.

Pyrolysis of Specific Non-Recyclable Waste Materials: Energy Recovery and Detailed Product Characteristics.

This study explores the pyrolysis process applied to various non-utilized waste materials, specifically focusing on separated plastics from municipal waste, wood waste (including pallets and window frames), paper rejects, and automotive carpets. Different combinations of these waste materials were subjected to pyrolysis, a process involving high-temperature treatment (600 °C) in a nitrogen atmosphere. The resulting products, including biochar, gas, and liquid fractions, as well as the residual waste materials, underwent comprehensive analysis. The evaluation of pyrolysis products emphasizes their quality, energy content, and potential applications. Notably, the pyrolysis gas derived from the combination of separated municipal plastics and waste wood exhibited the highest calorific value at 49.45 MJ/m3. Additionally, Mixture 2, consisting of plastic and wood waste, demonstrated the highest calorific value for the pyrolysis condensate, reaching 30.62 MJ/kg. Moreover, Mixture 3, benefiting from biochar utilization as a sorbent, displayed the highest iodine value at 90.01 mg/g.

Hazard evaluation of forest combustibles based on the correlation between pyrolysis products and combustion parameters.

Persistent organic pollutants (POPs) sourced by the forest fire release are emerging as significant contributors. Despite their increasing importance, the impact of forest fires on POPs remains inadequately explored and an unclear understanding. Herein, the research, choosing four typical forest combustibles, focuses on the relationship between typical POPs and wildfire parameters by assessing the predominant compounds and their concentration in POPs emissions from such fuels through molecular-level analysis. Experiments reveal forest combustibles thermally degrade to release products, releasing a variety of products, including acids (>7.94 %), aldehydes (>2.32 %), ketones (>3.40 %), alcohols (>7.70 %), esters (>2.33 %), ethers (>4.44 %), hydrocarbons (>6.36 %), aromatic compounds (>21.40 %), and nitrogen-bearing compounds (>11.83 %); notably, aromatic compounds, containing substantial concentrations, are also recognized as POPs. By delving into the pyrolysis (20 °C·ms-1) and burning processes (25, 35 and 50 kW/m2) of forest combustibles, we can gain a comprehensive understanding of the origin of POPs in wildfires. Moreover, Pearson correlation analysis is employed to establish connections between emitting volatiles and forest fire risk, further unveiling a significant correlation between fire hazards of forest combustibles and the presence of aromatic compounds (Correlation over 0.8). These findings are crucial for comprehending the POPs in forests and evaluating forest fire hazards at the molecular level.

Identification of mozambioside roasting products and their bitter taste receptor activation.

Arabica coffee contains the bitter-tasting diterpene glycoside mozambioside, which degrades during coffee roasting, leading to yet unknown structurally related degradation products with possibly similar bitter-receptor-activating properties. The study aimed at the generation, isolation, and structure elucidation of individual pyrolysis products of mozambioside and characterization of bitter receptor activation by in vitro analysis in HEK 293T-Gα16gust44 cells. The new compounds 17-O-ß-d-glucosyl-11-hydroxycafestol-2-on, 11-O-ß-d-glucosyl-16-desoxycafestol-2-on, 11-O-ß-d-glucosyl-(S)-16-desoxy-17-oxocafestol-2-on, 11-O-ß-d-glucosyl-15,16-dehydrocafestol-2-on, and 11-O-ß-d-glucosyl-(R)-16-desoxy-17-oxocafestol-2-on were isolated from pyrolyzed mozambioside by HPLC and identified by NMR and UHPLC-ToF-MS. Roasting products 11-O-ß-d-glucosyl-(S)-16-desoxy-17-oxocafestol-2-on, 11-O-ß-d-glucosyl-15,16-dehydrocafestol-2-on, and 11-O-ß-d-glucosyl-(R)-16-desoxy-17-oxocafestol-2-on had lower bitter receptor activation thresholds compared to mozambioside. Molecular docking simulations revealed the binding modes of the compounds 11-O-ß-d-glucosyl-15,16-dehydrocafestol-2-on and 11-O-ß-d-glucosyl-(R)-16-desoxy-17-oxocafestol-2-on and their aglycone 11-hydroxycafestol-2-on in the two cognate receptors TAS2R43 and TAS2R46. The newly discovered roasting products 17-O-ß-d-glucosyl-11-hydroxycafestol-2-on, 11-O-ß-d-glucosyl-(S)-16-desoxy-17-oxocafestol-2-on, 11-O-ß-d-glucosyl-15,16-dehydrocafestol-2-on, and 11-O-ß-d-glucosyl-(R)-16-desoxy-17-oxocafestol-2-on were detected in authentic roast coffee brew by UHPLC-ToF-MS and could contribute to coffee's bitter taste impression.

New insights into nitrogen control strategies in sewage sludge pyrolysis toward environmental and economic sustainability.

Sewage sludge (SS) contains a certain amount of nitrogen (N), resulting in various content of N in the pyrolysis products. Investigates on how to control the generation of NH3 and HCN (deleterious gas-N species) or convert it to N2 and maximize transforming N in sewage sludge (SS-N) into potentially valuable N-containing products (such as char-N and/or liquid-N) are of great significance for SS management. Understanding the nitrogen migration and transformation (NMT) mechanisms in SS during the pyrolysis process is essential for investigating the aforementioned issues. Therefore, in this review, the N content and species in SS are summarized, and the influencing factors during the SS pyrolysis process (such as temperature, minerals, atmosphere, and heating rate) that affect NMT in char, gas, and liquid products are analyzed. Furthermore, N control strategies in SS pyrolysis products are proposed toward environmental and economic sustainability. Finally, the state-of-the-art of current research and future prospects are summarized, with a focus on the generation of value-added liquid-N and char-N products, while concurrently reducing NOx emission.

Investigation on the formation mechanism of main products from TBBPA pyrolysis using DFT method.

The formation mechanisms of the main pyrolysis products of tetrabromobisphenol A (TBBPA) such as hydrogen bromide (HBr), bisphenol A compounds, and phenolic compounds were studied through using density functional theory (DFT) method at the theoretical level of B3P86/6-311 + G (d,p), and the effects of H and Br radicals on the formation mechanism of each product were analyzed. For the formation of each pyrolysis product, this paper presented various possible reaction pathways and acquired their thermodynamic parameters. Calculation results show that HBr can be produce. d continuously during the pyrolysis of TBBPA, and combination and abstraction reactions are the main ways for the generation of HBr. Br radical can abstract H atom from the phenolic hydroxyl groups of TBBPA to produce HBr, and this reaction is barrierless. When H radicals are involved in the initial reaction, the significance of the keto-enol tautomerism is negligible at all debrominations. The Br atom abstraction by H radical is the optimal pattern for debromination. TBBPA can be transformed into low-brominated bisphenol A through consecutive hydrodebromination reactions with trivial activation energies of 8.7-9.5 kJ/mol. The demethylation reaction is an initiation reaction for monomolecular pyrolysis of TBBPA and low-brominated bisphenol A, which is beneficial to the formation of phenolic compounds. During the pyrolysis of TBBPA, para-position Br atom of polybrominated phenol is easier to be removed and the energy barriers of rate-determining steps of the optimal reaction paths for the formation of 2,4,6-tribromophenol, 2,6-dibromophenol, 2,4-dibromophenol, 2-bromophenol, 4-bromophenol and phenol are 108.8, 7.6, 8.7, 8.1, 9.5, and 8.7 kJ/mol, respectively.

Pyrolysis and Gasification of a Real Refuse-Derived Fuel (RDF): The Potential Use of the Products under a Circular Economy Vision.

Refuse-Derived Fuels (RDFs) are segregated forms of wastes obtained by a combined mechanical-biological processing of municipal solid wastes (MSWs). The narrower characteristics, e.g., high calorific value (18-24 MJ/kg), low moisture content (3-6%) and high volatile (77-84%) and carbon (47-56%) contents, make RDFs more suitable than MSWs for thermochemical valorization purposes. As a matter of fact, EU regulations encourage the use of RDF as a source of energy in the frameworks of sustainability and the circular economy. Pyrolysis and gasification are promising thermochemical processes for RDF treatment, since, compared to incineration, they ensure an increase in energy recovery efficiency, a reduction of pollutant emissions and the production of value-added products as chemical platforms or fuels. Despite the growing interest towards RDFs as feedstock, the literature on the thermochemical treatment of RDFs under pyrolysis and gasification conditions still appears to be limited. In this work, results on pyrolysis and gasification tests on a real RDF are reported and coupled with a detailed characterization of the gaseous, condensable and solid products. Pyrolysis tests have been performed in a tubular reactor up to three different final temperatures (550, 650 and 750 °C) while an air gasification test at 850 °C has been performed in a fluidized bed reactor using sand as the bed material. The results of the two thermochemical processes are analyzed in terms of yield, characteristics and quality of the products to highlight how the two thermochemical conversion processes can be used to accomplish waste-to-materials and waste-to-energy targets. The RDF gasification process leads to the production of a syngas with a H2/CO ratio of 0.51 and a tar concentration of 3.15 g/m3.

Obtaining the best temperature parameters for co-carbonization of lignite (yatagan)-biomass (peach seed shell) by structural characterization.

In this study, Yatagan lignite (YL) and peach kernel shells (PKS) were originally taken separately and in a 1: 1 ratio by weight. Experiments were carried out in a 3-zone heated cylindrical furnace in a steel reactor. Structural characterization of all the solid products obtained was made by FTIR, XRD, and SEM analysis. When the FTIR and XRD spectra of the raw samples are examined, it is seen that they are rich in functional groups. It is seen that the PKS has aliphatic and aromatic structures and cellulosic structure -OH stresses (3500 cm-1). The sharp peak around 2918 cm-1 in Yatagan lignite belongs to the aliphatic C-H stretch. In the XRD spectrum, it is seen that both structures are largely amorphous. The raw PKS contains 3 different amorphous macromolecular structures. Yatagan lignite, on the other hand, contains crystalline peaks of clay and inorganic structures, depending on the ash content, as well as the amorphous structure. As the temperature increases depending on the carbonization temperature, as seen in the FTIR spectrum, the peaks of the functional groups decrease and disappear with the disruption of small macromolecular structures. As a result of the structural adjustment with the temperature increase, M-O-M peaks around 1000 cm-1 remain due to the aromatic C-H stretching and ash content. The paper centers around test assurance of operating temperatures in the consuming layer during co-carbonization. It is obtained that 800 °C is the best temperature condition for the co-carbonization process. It has been concluded that the chars obtained as a result of pyrolysis will be used as a solid fuel in both environmental (the lowest sulfur content) and economic (400 °C) sense. However, the fact that it has a very low sulfur content with the increase in the liquid and gas efficiency obtained at high temperatures again proves the production of an environmentally friendly liquid fuel.

Revealing and modeling of fire products in gas-phase for epoxy/black phosphorus-based nanocomposites.

This work aims at revealing and optimizing the mechanism, to promote the design of phosphorus-based flame retardants (PFRs) for controlling the spread of fire risk caused by the continuous spread of polymers. Herein, we synthesized about 10 nm TiO2 grown in situ on the surface of BP through a simple hydrothermal procedure to introduce it into epoxy (EP/BP-TiO2). In the first place, EP/BP-TiO22.0 nanocomposite achieves a reduction of 58.96% and 50.35% in PHRR and THR, respectively. Secondly, the pyrolysis of BP from Pn to P4, P3 and P2 is revealed. As a guide, P4 is established as a characteristic product of the analytical model for evaluating the effects in the gas phase for BP-based hybrids. Finally, this work clarifies the enhancement path for BP-TiO2 is optimized for the capturing of OH· and H· radicals by P4(POx). Crucially, this study reveals and controls the mechanism of the BP-based hybrids at the molecular level, which is expected to provide a promising analytical model for broad market PFRs design to address the risks and challenges of casualties and ecology caused by composites fire.

Optimization of Demineralization and Pyrolysis Performance of Eucalyptus Hydrothermal Pretreatment.

The preparation of bio-oil through biomass pyrolysis is promoted by different demineralization processes to remove alkali and alkaline earth metal elements (AAEMs). In this study, the hydrothermal pretreatment demineralization was optimized by the response surface method. The pretreatment temperature, time and pH were the response elements, and the total dissolution rates of potassium, calcium and magnesium were the response values. The interactions of response factors for AAEMs removal were analyzed. The interaction between temperature and time was significant. The optimal AAEMs removal process was obtained with a reaction temperature of 172.98 °C, time of 59.77 min, and pH of 3.01. The optimal dissolution rate of AAEMs was 47.59%. The thermal stability of eucalyptus with and without pretreatment was analyzed by TGA. The hydrothermal pretreatment samples exhibit higher thermostability. The composition and distribution of pyrolysis products of different samples were analyzed by Py-GC/MS. The results showed that the content of sugars and high-quality bio-oil (C6, C7, C8 and C9) were 60.74% and 80.99%, respectively, by hydrothermal pretreatment. These results show that the removal of AAEMs through hydrothermal pretreatment not only improves the yield of bio-oil, but also improves the quality of bio-oil and promotes an upgrade in the quality of bio-oil.

Catalytic co-pyrolysis of herb residue and polypropylene for pyrolysis products upgrading and diversification using nickel-X/biochar and ZSM-5 (X = iron, cobalt, copper).

It is very important to find cheap and efficient catalysts for catalytic co-pyrolysis. Catalytic co-pyrolysis of herb residue (HR) and reused polypropylene (PP) using Ni-X/biochar and ZSM-5 (X = Fe, Co, Cu) was performed to produce pyrolysis oil, pyrolysis gas and carbon nanotubes (CNTs) in a two-stage fixed bed reactor. Bimetallic biochar catalysts exhibited higher catalytic activity due to their higher specific surface area (SBET) and more strong acid sites. NiCu/biochar significantly increased the yield of pyrolysis oil by enhancing Fischer-Tropsch synthesis. In addition, the stronger secondary cracking capacity of NiCu/biochar resulted in the highest content of hydrocarbons (80.47%) and C6-C11(61.10%), while the availability of higher content of carbon source gas also facilitated the formation of CNTs and H2 at back-end. The cheap and efficient NiCu/biochar catalyst has great potential in the application of catalytic pyrolysis, which is conducive to the large-scale promotion of biomass pyrolysis technology.

Migration and transformation of heavy metals in Chinese medicine residues during the process of traditional pyrolysis and solar pyrolysis.

Chinese medicine residues (CMRs) have always been considered difficult to realize resource treatment because of the possible residual heavy metals (HMs). In this study, CMRs containing HMs (Cu, Cd and Pb) were pyrolized in the tube furnace and the solar pyrolysis equipment. The ratio of HMs entering the pyrolysis products (bio-gas, bio-oil and bio-char) and the stability of HMs in biochar were analyzed. A comparative analysis showed that the less volatile HMs were basically concentrated in the biochar after the pyrolysis treatment, indicating that pyrolysis could enrich the HMs in the biochar. The leaching experiments showed that the leaching rates of Cu, Cd and Pb from biochar were 0-0.41%, 0-3.03% and 0.09-0.86% respectively, while the leaching rates of CMR were as high as 18.85, 10.98 and 2.52%, indicating that the pyrolysis process could improve the fixation effect of HMs in biomass to a greater extent and reduce the leaching toxicity of HMs. Compared with the traditional pyrolysis method, the solar pyrolysis had the same effect on the enrichment and stabilization of heavy metals in CMRs, which means that it is possible to realize the resource treatment of CMR through a renewable green energy (solar energy).

Co-pyrolysis of biomass and polyvinyl chloride under microwave irradiation: Distribution of chlorine.

Co-pyrolysis of sophora wood (SW) and polyvinyl chloride (PVC) was conducted in a microwave reactor at different temperatures and different mixing ratios, and the transformation and distribution of chlorine in pyrolysis products were investigated. Microwave pyrolysis is a simple and efficient technique with better heating uniformity and process controllability than conventional heating. Compared with PVC pyrolysis, the addition of SW significantly reduced CO2 yield and greatly increased the yield of CO. The yield and quality of pyrolysis oil were effectively improved by SW, and the content of chlorine-containing compounds in the oil was suppressed to <1% at low temperatures (<550 °C). Co-pyrolysis of SW and PVC reduced the chlorine emissions from 59.07% to 28.09% and promoted the retention of chlorine in char (from 0.33% to 4.72%). Cellulose, hemicellulose, and lignin were co-pyrolyzed with PVC to investigate their effects on chlorine distribution. The experiments demonstrated that lignin had the most significant effects on reducing gas phase chlorine emission and achieving chlorine immobilization, and chlorine mainly existed in the form of sodium chloride in the char of lignin-PVC co-pyrolysis. Hence co-pyrolysis of lignocellulosic biomass and PVC provides a practical pathway for utilization of PVC waste in an environmentally friendly manner, realizing efficient chlorine retention and significantly reducing chlorine-related emissions.

Valorization of rubberwood sawdust and sewage sludge by pyrolysis and co-pyrolysis using agitated bed reactor for producing biofuel or value-added products.

This study investigated experimentally pyrolysis of rubberwood sawdust (RWS), sewage sludge (SS), and their blends (25:75, 50:50, and 75:25 by weight) in an agitated bed pyrolysis reactor. The yields and characteristics of liquid product and biochar were determined for pyrolysis at 450, 500, and 550 °C and were affected both by temperature and feedstock type. The liquid and biochar yields were in the ranges 27.30-52.42 and 21.43-49.66 (wt%). Pyrolysis of RWS at 550 °C provided the highest liquid yield, while SS gave a high biochar yield. Co-pyrolysis of SS with RWS improved yield and quality of liquid and biochar products. The liquid product had 57.54-70.70 wt% of water and a low hydrocarbon content. The higher heating value (HHV) of water-free liquid product was 14.73-22.45 MJ/kg. The major compounds of liquid product included acetic acid, 2-propanone, 1-hydroxy, and phenols according to GC-MS. The biochar from RWS had a high carbon content (83.37 wt%) and a high HHV (33.57 MJ/kg), while SS biochar was mainly ash (67.62 wt%) with low carbon content. The SS biochar also had high contents of Si, Ca, Fe, K, and Mg as determined by XRF. Co-pyrolysis of SS with RWS improved the biochar by increasing its carbon content and reducing ash and inorganic elements. The surface of RWS biochar was more porous, while SS biochar had the larger specific surface according to SEM and BET. Based on these results, co-pyrolysis of 75:25 feedstock mix is recommended for further studies on applications of liquid product and biochar.

Catalytic pyrolysis of tire waste: Impacts of biochar catalyst on product evolution.

Tire scrap is a solid waste that can be potentially used as the feedstock for the production of liquid fuels via the thermochemical process such as catalytic pyrolysis. Nevertheless, it remains challenging to develop the efficient while cost-effective catalyst for the catalytic pyrolysis of tire. In this study, the pyrolysis of tire scrap at 500 °C with the biochar produced from the gasification of poplar wood at 850 °C were conducted. The biochar catalyst significantly affected the evolution of the volatiles and the char properties, while had a slight impact on the yields of the gas, tar and char products. The biochar catalyst catalyzes the cracking of limonene, a major liquid product in tar, to form significantly more propane in gases and alkanes or alkenes in the tar. In addition, the interaction between the biochar with the oxygen-containing organics promoted the re-condensation reaction, which increased the oxygen content in the char, but the biochar catalyst did not influence the evolution of the aromatics. Additionally, the catalytic pyrolysis also makes the biochar catalyst more oxygen-deficient and more resistant towards oxidation. Concluding all the results showed that biochar, which were produced from the gasification of poplar wood can be a potential catalyst for the pyrolysis of tire.

Thermal degradation of waste plastics under non-sweeping atmosphere: Part 2: Effect of process temperature on product characteristics and their future applications.

The current energy demand and diminishing conventional fuels have forced researchers to find an alternative source of energy. Waste to energy is the current trend for converting waste materials (plastic waste) into valuable fuels. This article mainly discussed the detailed characterization of the pyrolytic products, their comparative analysis and the reaction mechanism at varying operating temperature. This article is a successor of part 1, which primarily focused on the characterization of different waste plastics, their TG analysis, the effect of reactor temperature on yield analysis in a batch reactor and their detailed degradation mechanism. Furthermore, the results presented in this article report the characterization of products at three processing temperatures of 450, 500 and 550 °C. The pyrolytic oils from all wastes excluding PS show a very low density ranging from 0.71 to 0.76 kg/m3, whereas PS pyrolytic density is reported between 0.86 and 0.88 kg/m3. The viscosity of oils increases with an increase in the processing temperature and is similar to the conventional fuels. The FTIR analysis of the products (oil & gases) obtained from HDPE, PP and mixed plastic waste (MIX) shows a large presence of alkanes and a higher presence of aromatics. PS analysis reported a large presence of aromatics (~75%). The GC-MS analysis of all pyrolytic oils from waste plastics, simulated wastes (virgin plastics) and distilled fraction of MIX pyrolysis oil is compared. The GC analysis of non-condensable gases at all processing temperature reports that MIX produce the maximum H2; HDPE, PS and MIX produces a high amounts of CH4 too. The formation of lower hydrocarbons (C5-C12) in pyrolysis oil shows a trend as MIX > PP > PS > HDPE, while for the heavier hydrocarbons (>C19) it is HDPE > PP > PS > MIX. The potential of the utilization of these products has been discussed in different sectors for future research.

An assessment of how distance and diesel oxidation catalyst will impact thermal decomposition behaviors of particles.

Decomposition mass loss and pyrolysis products analyses of particles sampled at various locations along the tailpipe of a Euro-IV diesel engine were performed using a thermogravimetry in conjunction with Fourier transformation infrared spectrometry-mass spectrum. Diesel particles were collected at the same location with and without diesel oxidation catalyst (DOC) mounted on the test engine separately. The three poles in thermal gravity-differential thermal gravity images suggested that the decomposition process of diesel particles could be divided into three stages which correspond to the decompositions of lower boiling substances, higher boiling substances and soot respectively. It is noticed that no matter whether DOC was mounted or not, the further the particles were sampled away from the engine block, the lower the peak temperatures and the heavier the mass losses within the first two stages, which indicated that the soluble organic fraction in the particle samples increased and therefore lowering the activation energy of thermal decomposition. Hydroxyl, ammonia, CxHy fragments, benzene, toluene, and phenol were found to be the primary products of particle decomposition, which didn't change with the location of particle sample point. The employment of DOC increased the activation energy for particle oxidation and resulted in a higher peak temperature and lower mass loss within the first-stage. Moreover, the CO stretching bands of aldehyde and ketone at 1771 cm-1 was only detected without a DOC, while the NO2 peak at 1634 cm-1 was solely noticed with the presence of DOC. Compared to the first-stage pyrolysis products, more polycyclic aromatic hydrocarbons and less CxHy fragments were seen in the second-stage.

Pyrolysis of sewage sludge by solid heat carrier.

The experimental study of fast pyrolysis of dried sewage sludge in the retorting system with solid heat carrier was performed. The yield of the main pyrolysis products such as gas, oil, pyrogenic water, and solid residue (pyrolytic char) was measured in the 490-580 °C range. The maximum oil yield in an amount of 38.5 wt% on dry ash free basis was registered at a temperature of 550 °C. The gas chromatographic-mass spectrometric (GC-MS) analysis of pyrolytic oil allows the identification of 58 hydrocarbons of different structures and different classes such as aliphatic, aromatic, oxygenated and nitrogen-containing compounds. The group composition of the obtained oil makes it possible to identify it as an analog of crude oil, which can be processed by standard technologies. The technological scheme of the facility for pyrolysis of sewage sludge based on the technology Galoter for the thermochemical processing of low-grade fuels was proposed with corresponding material and heat balance.

Reinforcement of the bio-gas conversion from pyrolysis of wheat straw by hot caustic pre-extraction.

BACKGROUND: Pyrolysis has attracted growing interest as a versatile means to convert biomass into valuable products. Wheat straw has been considered to be a promising biomass resource due to its low price and easy availability. However, most of the products obtained from wheat straw pyrolysis are usually of low quality. Hot soda extraction has the advantage of selective dissolution of lignin whilst retaining the carbohydrates. This can selectively convert biomass into high-quality desired products and suppress the formation of undesirable products. The aim of this study was to investigate the pyrolysis properties of wheat straw under different hot caustic pretreatment conditions. RESULTS: Compared with the untreated straw, a greater amount of gas was released and fewer residues were retained in the extracted wheat straw, which was caused by an increase in porosity. When the NaOH loading was 14%, the average pore size of the extracted straw increased by 12% and the cumulative pore volume increased by 157% compared with the untreated straw. The extracted straw obtained from the 14% NaOH extraction was clearly selective for pyrolysis products. On one hand, many lignin pyrolysis products disappeared, and only four main lignin-unit-pyrolysis products were retained. On the other hand, polysaccharide pyrolysis products were enriched. Both propanone and furfural have outstanding peak intensities that could account for approximately 30% of the total pyrolysis products. However, with the excessive addition of NaOH (i.e. > 22% w/w) during pretreatment, the conversion of bio-gas products decreased. Thermogravimetric and low-temperature nitrogen-adsorption analysis showed that the pore structure had been seriously destroyed, leading to the closing of the release paths of the bio-gas and thus increasing the re-polymerisation of small bio-gas molecules. CONCLUSIONS: After suitable extraction (14% NaOH loading extraction), a considerable amount (25%) of the soluble components dissolved out of the straw. This resulted in an increase in both pore size and volume. This condition appeared to be optimally selective for the release of value-added pyrolysis products such as furfural, ketones and lignin monomer units. However, excessive addition of alkali (22%) for extraction could change the original interior structure, resulting in a decrease in both pore size and volume. This interior structure modification limited the release of pyrolysis products, and greater carbonisation occurred.

Anti-tumor Effect of Ginsenoside Rg1 Pyrolysis Products (HPPRg1) on H22 Tumor-bearing Mice / 中国药学杂志

OBJECTIVE: To investigate the antitumor effect and molecular mechanism of ginsenoside Rg1 pyrolysis products (HPPRg1) on H22 tumor bearing mice. METHODS: To establish tumor model of transplanting H22 tumor-bearing mice and observe the anti-tumor effects of HPPRg1, H22 tumor-bearing mice were randomly divided into groups of control, model, cyclophosphamide (CTX, 30 mg·kg-1), low dosage of HPPRg1 (HPPRg1-L, 10 mg·kg-1), middle dosage of HPPRg1 (HPPRg1-H, 20 mg·kg-1) and high dosage of HPPRg1 (HPPRg1-H, 40 mg·kg-1) groups, respectively. Through evaluating inhibition rates of tumors, organ indices, and levels of TNF-α, IFN-γ and IL-2 to observe the anti-tumor effect of HPPRg1. In addition, H&E and Hoechst 33258 straining were used to observe the apoptosis of H22 tumor cell. RESULTS: Compared with the model group, the three dose groups of HPPRg1 can inhibit tumor proliferation. Mainly through the inhibition of tumor cell proliferation and pro-apoptosis to exert anti-tumor effect. CONCLUSION: HPPRg1 has a significantly inhibitory effect on H22 tumor-bearing mice, the mechanism may related to promote apoptosis of tumor cells and improve immunity.