Search

Pyrolysis of plant biomass is a promising way to produce charcoal (solid), tar and pyroligneous acid, and other gaseous products. These products are of great import as they are alternative to traditional fuels and inorganic chemicals. In this review, main emphasis has been given to properties of pyroligneous acid and its potential benefits in agriculture. Pyroligneous acid is a crude condensed, highly oxygenated organic liquid which is a by-product of pyrolysis of plant biomass. It mainly consisted of aliphatic, aromatic, and naphthenic hydrocarbons and other oxygenated compounds such as alcohols, aldehydes, ketones, furans, acids, phenols and ethers. Pyroligneous acid exhibits antioxidant and scavenger properties and has been used in agriculture as antimicrobial agent, insecticide, and for the promotion of seed germination and plant growth. This review takes a critical look at some of the production principles, roles of pyroligneous acid in plant growth, development and defense, and the prospects and broader application of pyroligneous acid in agriculture. It is envisaged that this review will generate global discussion and create awareness for the numerous opportunities in pyroligneous acid research and global use.

Urea is one of the most commonly used nitrogen fertilizers in agricultural soil and is easily decomposed by soil urease resulting in ammonium release. The produced ammonium can be volatilized or converted to nitrate, which is susceptible to leaching, leading to groundwater contamination unless used by plants. Hence, it is important to control the release of nitrogen from the urea. Pyroligneous acid inhibited the urease activity and decreased ammonium release up to 80% compared to the control. Amidase including asparaginase and glutaminase is an enzyme that catalyzes hydrolysis of amide group, similar to urease. Therefore, the effect of pyroligneous acid on the inhibition of soil amidase was also tested and the results showed that pyroligneous acid competitively inhibited asparaginase while glutaminase was not inhibited. However, inhibitory effect of pyroligneous acid on asparaginase was negligible compared to the urease. The application of pyroligneous acid with a smaller amount of urea for controlled nitrogen release during Chinese cabbage growth showed that dry biomass and nutrient contents of Chinese cabbage were similar to the case of the conventional urea application. The nitrogen utilization efficiency (NUE) was highest for 33% less amount of urea supply with pyroligneous acid (2.21) compared to conventional treatment (1.81). Consequently, the use of pyroligneous acid with urea enhances nitrogen use efficiency while also protecting environments from non-point source contamination.

Remediation of agricultural soils polluted with antibiotic resistance genes (ARGs) is important for protecting food safety and human health. However, the feasibility of co-application of biochar and pyroligneous acid, two multifunctional soil amendments, for mitigating dissemination of soil ARGs is unknown. Thus, a woody biochar (BC450) and its by-product, pyroligneous acid (PA450) simultaneously produced at 450 °C from blended wood wastes, were used to compare their individual and combined effects on soil ARG abundance using a 65-day pot experiment planted with leafy vegetable Brassica chinensis L. The individual and combined applications of PA450 and BC450 significantly reduced the absolute abundance of ARGs by 65.7–81.4% and 47.5–72.9% in the corresponding rhizosphere and bulk soil. However, the co-application showed little synergistic effect, probably due to the counteractive effect of BC450 on the PA450-mitigated soil ARG proliferation, resulted from the promoted soil bacterial growth and/or adsorption of antimicrobial components of PA450 by BC450. The decreased abundances of mobile genetic element intI1 and Tn916/1545 in the PA450 treatments demonstrated the potential of PA450 for weakening horizontal gene transfer (HGT). Furthermore, weakened HGT by individual PA450, lowered availability of heavy metals by individual BC450, and different bacterial community (e.g., reduced ARGs bacterial host) together with improved soil properties from co-application of PA450 and BC450 all contributed to the reduced ARG level. This study highlighted the feasibility of co-applications of biochar and pyroligneous acid amendment for mitigating soil ARG pollution. These findings provide important information for developing eco-friendly technologies using biochar and pyroligneous acid in remediating ARG-contaminated soils.

The biochar (BC), pyroligneous acid (PA), and gas were collected from cotton stalks based on a polygeneration process, and this study was systematically focused to develop and process biochar and its byproducts obtained with various pyrolysis temperatures (300, 350, 400, 450, 500, and 550 °C). The results showed that the yield of biochar decreased from 46.71 % to 30.26 % as the pyrolysis temperature was increased from 300 to 550 °C, and this was accompanied by an increase in carbon content from 71.32–78.02%. Heatmap analysis on the correlation among pyrolysis temperature of biochar and elements illustrated that the content of C, H, and O were highly correlated with pyrolysis temperature of biochar. The ketones, phenols, alcohols, acids, and alkyl phenyl ethers were the major chemical constituents. The maximum total content of amino acids reached 647.1 mg/kg when the pyroligneous acids were collected at 450 °C. Moreover, the volume fractions of gas (CO and CH4) content increased with increasing pyrolysis temperature, leading to an increase in the gas heating value. Overall, the outcomes presented above indicated that the polygeneration system would be environmentally benign and effective in producing biochar, pyroligneous acids, and gas, which provides economic benefits and suggests a potential industrial application for cotton stalk.

A substantial percentage of manure nitrogen (N) can be lost as gaseous ammonia (NH3) during storage and field spreading. Lowering slurry pH is a simple and accepted method for preserving its N. Efficiency of slow pyrolysis liquid (PL) produced from birch (Betula sp.) as an acidifying agent, and its ability to reduce NH3 emissions following surface application of cattle slurry, was studied in a field experiment. Untreated slurry (US) and slurries acidified with PL and sulfuric acid (SA) were applied to the second harvest of a grass ley. Immediate NH3 emissions, grass biomass, N-yield and possible toxic impacts on soil nematodes and enchytraeids were examined. Furthermore, the effects on soil respiration, nitrogen dynamics and seed germination were studied in subsequent laboratory experiments. In the field, over one third of the water-extractable ammonium-N (NH4-N) applied was lost through NH3 volatilization from US. SA and PL acidified slurries reduced NH3-N emission rate equally from 3.4 to

Hydrogen gas was produced from the catalytic reformation of pyroligneous acid (PA)with modified bimetallic Al-SBA-15 catalysts. Al-SBA-15 catalysts with different aluminum loading contents were prepared through one-step hydrothermal synthesis. Monometallic M-Al-SBA-15 (M = Ni, Fe, Co, and Sn) and bimetallic M/N-Al-SBA-15 (M-N = Ni-Fe, Ni-Sn, and Ni-Co) catalysts were synthesized through impregnation. The catalysts were characterized via N 2 adsorption-desorption, scanning electron microscopy(SEM), X-ray photoelectron spectroscopy(XRD), and X-ray photoelectron spectroscopy(XPS) analysis and so on. Bimetallic M-N-Al-SBA-15 catalysts exhibited higher catalytic activity and carbon deposition resistance than monometallic M-Al-SBA-15 catalysts. Sn facilitated the combination of Ni with Al into a NiAl 2 O 4 spinel in the carrier. Ni/Sn-Al-SBA-15 bimetallic catalyst showed excellent catalytic activity and carbon deposition resistance. The H 2 yield was 30.1 mg/g and H 2 content remained 40% after 16 h under the optimal reaction conditions via the Ni/Sn-Al-SBA-15 catalyst.

Pyrolysis temperature and subsequent preservation time have a significantly influence on the chemical components and properties of pyroligneous acids. In this study, the pyroligneous acids were successively generated by a polygeneration process from the cotton stalk (CS). The pyrolysis process was systematically investigated by using a laboratory-scale pyrolysis retort under different pyrolysis temperatures (300, 350, 400, 450, 500, and 550 °C). Pyroligneous acids of one month storage and six months storage were analyzed and compared in the chemical composition and properties. Results showed that the total amino acid content of pyroligneous acid stored for six months was significantly lower than that in one-month storage. The pyroligneous acid of six months storage showed better inhabitation of some bacteria activities than that of one month. This phenomenon was associated with the increment of phenol and ketone compounds. The data also presented indicated that the pyroligneous acids obtained from 450 °C pyrolysis temperature via six months storage were more appropriate for an antimicrobial and pesticidal agent. The preliminary screening of pyrolysis temperature and storage time could provide a promising practical basis for the economic benefit and performance of pyrolysis products from cotton stalk.

Quality deterioration and fungal pathogen infection always cause severe yield loss for fresh fruit at postharvest stage. Hence, safe and efficient measures are in great demand. In the present study, the efficacy of bamboo pyroligneous acid (BPA) for improving intrinsic antioxidant capacity and inducing defense responses of harvested apple fruit was assessed. BPA treatment (250 and 500 mL L−1) dramatically activated the activities of major enzymes in phenylpropanoid metabolic pathway and antioxidant enzymes, ameliorated free radical scavenging capacity, resulting in elevated total flavonoid and total phenolic contents. The lower malonaldehyde (MDA) content and H2O2 level also indirectly reflected the antioxidant efficacy of BPA. Moreover, BPA (10, 20, 30 mL L−1) also significantly inhibited mycelial growth of Botrytis cinerea by inducing reactive oxygen species burst, leading to impairment in membrane integrity and cell vitality as well as leakages of cytoplasmic contents. Taken together, these findings demonstrated that BPA was effective for maintaining intrinsic quality of apple fruit and inhibiting gray mold, which may be promising for alleviating quality deterioration and controlling diseases caused by fungal pathogens.

Both biochar (BC) and wood vinegar (WV) influence the nitrous oxide (N2O) and methane (CH4) emissions from agricultural systems. However, the impacts of BC and WV co-application on rice production, N2O and CH4 emissions are not well documented. We here conducted a two-year soil columns experiment with four treatments: WV (5 t WV ha−1), BC (7.5 t BC ha−1), WV + BC (5 t WV ha−1 +7.5 t BC ha−1) and a control (no treatment). The results showed that BC and WV + BC produced higher rice grain yield than the control by 14.1–15.9% in 2016 and by 4.1–5.2% in 2017, respectively. While WV increased rice grain yield by 11.2% in 2016, it had no significant influence on yield in 2017. Both WV and BC significantly mitigated N2O emissions by 22.4–41.8% in 2016 and 22.4–36.9% in 2017, respectively. Interestingly, WV + BC treatment showed the highest N2O mitigation efficiency, with a 52.9–62.8% mitigations in 2016 and 2017. Furthermore, the co-application of WV and BC significantly mitigated CH4 emissions by 42.6% in 2016 and 35.3% in 2017, respectively, while applying WV or BC alone had no annually-consistent mitigation effect on CH4 emissions. Overall, GWPt of rice growth cycle was most significantly suppressed by WV + BC with a 48.7–56.1% reduction, followed by WV and BC with 20.4–28.0% and 19.7–35.7% reductions, respectively. Consequently, the WV + BC treatment had the highest GHGI mitigation effect, averaging with 56.7% over two consecutive rice growth cycles. In conclusion, co-application of WV and BC is recommended for rice cultivation, which can both improve rice yield and minimize GHG emissions.

Li4SiO4 has been demonstrated as a promising adsorbent for CO2 capture. However, Li4SiO4 adsorbents from the conventional solid-state method usually exhibit dense microstructures and, thus, poor CO2 capture performance. Treating Li4SiO4 with organic acids has been proved effective to improve the microstructures. The commonly used acids such as acetic acid, citric acid and gluconic acid are too expensive, restricting the application of this modification technique. In addition, in the typical Li4SiO4-based CO2 capture looping system, CO2 usually exists in the desorption reactor. However, the effect of the existence of CO2 at the desorption stage on adsorption performance has been rarely studied. Focusing on these two issues, this work employed pyroligneous acid (PA), a low-cost by-product of the fast pyrolysis of biomass, to modify the microstructures of Li4SiO4. It was found that modification by pyroligneous acid (PA) successfully improved the microstructures and enhanced the surface area of Li4SiO4 adsorbent. As a result, the obviously improved CO2 adsorption performance was achieved. In addition, the test results under CO2-containing desorption atmospheres indicated that the existence of CO2 at the desorption stage decreased the adsorption performance due to the severe sintering caused by the existence of CO2 at the desorption stage.

Pyroligneous acid was produced by subjecting the stem and leaves of pineapple plants from a local plantation area to slow pyrolysis in a charcoal kiln for 48 h. The concentrated pyroligneous acid from pineapple plant waste biomass (CPAP: Concentrated pyroligneous acid from pineapple waste biomass) and its dichloromethane extract (DCPAP: Dichloromethane extract of concentrated pyroligneous acid from pineapple waste biomass) was found to exhibit scavenging activity against DPPH (78.3% and 89.7%), ABTS (61.1% and 96.8%) and superoxide radical (79.3% and 85%). DCPAP exhibited higher scavenging activity than CPAP due to higher total phenolic content (9.5 ± 0.11 mg gallic acid equivalents (GAE)/g of DCPAP sample; 2.67 ± 0.14 mg GAE/g of CPAP sample). Chemical profiling by GC–MS showed that DCPAP has a high content of phenolic compounds (69.5%) especially 2,6-dimethoxy phenol, phenol, 1,2-benzenediol, 3-methoxy 1,2-benzenediol and 2-methoxy phenol which are known to possess antioxidant properties and are derived primarily from the thermal decomposition of lignin in biomass. Phenols, alkyl aryl ethers and ketones were identified as the major constituents, while furan and pyran derivatives, sugars, acids, esters, aldehydes and alcohols were the minor constituents. Both CPAP and DCPAP also exhibited reducing power and lipid peroxide inhibitory activity (97.2% and 79%) showing that pyroligneous acid could serve as an alternative ecofriendly source of natural antioxidants.

We studied the pyrolysis process and products of Rosmarinus officinalis leaves. Three kinds of plant materials were used: fresh leaves, air-dried leaves, and air-dried leaves after essential oil distillation. The pyroligneous acids (PA) obtained by pyrolyzing the plant materials with different heating powers were extracted with organic solvents, including methanol, ethyl formate, dichloromethane, thiophene and tetrahydrofuran. The antioxidant activities, including free radical scavenging activity and ferric reducing power of the PA extracts were investigated. The synthetic antioxidants BHA and BHT were used as positive controls. The dichloromethane extract of PA showed superior antioxidant properties. The chemical compositions of the extracts were determined by GC–MS, and further proved that the dichloromethane extract had the best antioxidant characteristics.

Experimental investigations have been carried out on the calcium oxide obtained by the calcination of domestic limestone from eastern Taiwan to determine the absorption performance of CO2. Repetitive carbonation/calcination reaction with modified sorbents, i.e., the synthetic sol–gel sorbent (sol–gel), limestone modified with pyroligneous acid (PA), and cesium-doped CaO sorbents (doped Cs) in a fixed bed was operated to enhance the reactivity and durability of the sorbents for CO2 capture. The liquid-phase hydration treatment on the modified sorbent was also employed to improve the capture capability of CO2. Conversions for the repetitive carbonation/calcination reaction of modified sorbents were evaluated under different operating conditions. The empirical models for the decay of the CO2 capture by the previous investigation were presented in comparison with the experimental results.

Wood vinegar (WV) or pyroligneous acid and fermented bioextracts (FB) from plants or animal residues, have been used in agriculture in an attempt to reduce the dependence on the use of chemicals. The objective of this study was to investigate the effects of WV and FB on growth and yield of tomato, cv. Delta, in pot and field experiments. The study was undertaken between December 2008 and May 2009. A split-plot design with four replications was used. The main-plot treatments comprised high and low application rates of chemical fertilizer, while the sub-plot treatments were water, diluted FB (1:500 by volume), WV (1:800 by volume) applied as soil drench and foliar spray, in nine treatment combinations which included untreated control treatment. The foliar spray and soil drench treatments were applied at 10 day-intervals after transplanting (30 days after emergence). The results of two experiments were in agreement, with rates of chemical fertilizer clearly increasing the yield of tomato (P

Catalytic upgrading of pyroligneous acid, by-product from slow pyrolysis of woody biomass for char production, was carried out using zirconia-supported iron-oxide catalysts under a steam atmosphere at temperatures ranging from 623 to 723 K, and the effect of ZrO 2 content in the ZrO 2 –FeO X catalysts on catalytic activity and ketone yields was investigated. It was demonstrated that hydroxyacetone and carboxylic acids (acetic and propionic acids) in the pyroligneous acid were converted into aliphatic ketones (acetone and 2-butanone) via a ketonization reaction over the ZrO 2 –FeO X catalyst. However, reaction inhibition by metal impurities in the pyroligneous acid such as potassium (K) and magnesium (Mg) was also observed. These metal impurities could be removed from the pyroligneous acid without changing the organic composition by using an ion-exchange resin. The removal of the metal impurities was effective in increasing the ketone yields. Moreover, as the W / F value ( W : Amount of catalyst, and F : Flow rate of the pyroligneous acid in the feed) increased, the ketone yield increased up to approximately 30 C mol%, and the ketone fraction in the liquid product reached 55 C mol%.

Hydrogen production by supercritical water gasification (SCWG) of biomass is a unique process of producing energy without drying of the biomass. Especially liquid by-product streams offer via SCWG the possibility of energetic utilization in comparison to waste disposal. In this paper the parameters temperature, residence time, TOC-concentration of the feed and potassium carbonate as catalyst for the hydrothermal gasification of pyroligneous acid are studied. Pyroligneous acid is a liquid by-product of charcoal production mainly composed of acetic and formic acid. Results measured with different lab-scale reactors and a pilot plant with a maximum throughput of 100 kg/h are presented. The experiments show an increase of gasification efficiency at high temperatures, low TOC-concentration of the feed, moderate residence times and the addition of potassium carbonate.

Tannery effluent (sludge, wastewater) is treated by natural way. The waste sludge has been taken for two treatment process. The alkali chemicals are neutralized by pyroligneous acid which is obtained by pyrolysis process of wood. This sludge is sent out for drying. The dried sludge contains some crack pattern formation. Photographs were used to record two sludge cracking surfaces. Experiment has been performed to study the fracture pattern formation in thin film sludge. We studied changes of crack surface of a sludge by image analysis and also assessed applicability of fractal scaling to crack surfaces. The calculated crack surface dimension shows that the fracture surface exhibit fractal structure. Image size was 256 × 256 pixels. MFA (multifractal analysis) was carried out to the method of moments, i.e., the probability distribution was estimated for moments ranging from −150

This paper addressed the probability of the generation of ultra-clean coal from chemical leaching of low-rank Victorian brown coal. Sequential leaching was employed to determine the modes of occurrence of the major elements in the two coals studied, including Na, K, Mg, Ca, Fe, Al, Ti, and Si. The results indicate that, the modes of occurrence of individual metals vary greatly with brown coal sample and elemental type. For one brown coal tested, it is dominated by water-soluble and ammonium acetate-soluble ion-exchangeable cations. Therefore, a single washing through the use of woody biomass-derived pyroligneous acid or citric acid easily reduced the concentrations of its overall ash and even sulphur and chlorine to meet the requirements for gas turbine fuel. The leaching of the organically bound cations in this coal was also very rapid and completed in 5 min. In contrast, another brown coal tested is mainly composed of quartz and/or clay compounds which remained intact even after being leached with 5 M nitric acid. These mineral grains possess two peak size ranges in the coal, 1.0–2.2 μm and 4.6–10 μm. The former size bin was embedded deeply in coal matrix, and hence, its leaching upon acids was very slow when compared with coarse particles which are mostly discrete grains residing separately from coal matrix. The Na–EDTA was found to be able to mobilise the small grains substantially through its Na ion to penetrate coal matrix to react with Al, forming acid-soluble Na aluminates. The ammonium acetate-insoluble Ti and Fe polyhedra were also mobilised by the EDTA. Accordingly, the overall ash content in coal residue accounts for ~ 1.5 wt.%, relative to 2.6 wt.% in the corresponding raw coal and 2.0 wt.% in the ammonium acetate-insoluble residue.

Based on differences in acidity, organic acids and phenols were enriched by pH gradient extraction method from walnut shell pyroligneous acid. Contents of organic acids and phenols were measured by acid–base titration method and Folin colorimetric assay, respectively to assess the effectiveness of the extraction. In addition, the antimicrobial activity of the organic acids and antioxidant activity of phenols extracted were investigated. Chemical components of the extracts that were from the optimal concentrations of NaHCO3 and NaOH were measured by GC–MS. The results showed that 5% NaHCO3 could enrich the highest amount of organic acids, whereas 4% NaOH could enrich the highest amount of phenols. The enriched organic acids exhibited high antimicrobial activity, and the enriched phenols exhibited antioxidant activity under low concentrations, and demonstrated dosage dependency.

Three kinds of pyroligneous acids were prepared from walnut shell at different temperature ranges (low: 90–150 °C, SP1; middle: 151–310 °C, SP2; and high: 311–550 °C, SP3). The chemical profiles of the acids were established by GC–MS. Antioxidant activities of the acids were investigated from the aspects of DPPH free radical scavenging capacity, hydroxyl free radical scavenging capacity, superoxide anion radical scavenging capacity, reducing power, and anti-lipid peroxidation capacity. The results indicated that the chemical constituents of pyroligneous acids were similar, mainly phenols, organic acids, ketones, and furan derivatives. However, the contents of each constituent in three acids varied. All the pyroligneous acids exhibited antioxidant activity, but with different levels. The acid SP3 collected from high temperature range showed the strongest antioxidant activity, followed by those from middle (SP2) and low (SP1) temperature ranges. It was considered that the strongest antioxidant activity of SP3 was due to its highest content of phenols among the three acids. It is hopeful to develop food antioxidant from SP3.

To achieve a comprehensive utilization of walnut tree branches, a waste from the cultivation of walnut fruit, pyroligneous acids were prepared and collected by pyrolyzing walnut tree branches at three temperature ranges, 90–230 °C, 230–370 °C and 370–450 °C. Antimicrobial activity of each pyroligneous acid was tested. Chemical constituents of the pyroligneous acid collected from 230 to 370 °C, which showed the strongest antimicrobial activity were analyzed by GC-MS. The results showed that the temperature range to produce pyroligneous acid from walnut tree branches was 90–450 °C. All the pyroligneous acids collected from three temperature ranges showed antimicrobial activities, while the pyroligneous acid collected from 230 to 370 °C showed strongest antimicrobial activity. Fifty compounds were found by GC–MS analysis from the pyroligneous acid collected at this temperature range, namely organic acids, phenols, ketones phenyl ethers, and furan and pyran derivatives, others with lower contents were alcohols, esters, sugar derivatives, and nitrogen compounds. Phenols and organic acids accounted for 63.46% of the total constituents detected. It is suggested that phenols and organic acids are the active components for antimicrobial activity.

This paper presents results of experiments undertaken to determine the performance of a direct injection (DI) diesel engine fuelled by blends of kiln-produced pyroligneous tar (PT) and diesel. The PT was sourced from Bulgaria where it was produced from a pine feedstock via a traditional kiln method that involves separation of the aqueous pyroligneous acid fraction. The tar is characterized by high carbon concentration, viscosity and high heating value. Although high, at fuel injection temperatures over 120 °C the tar's viscosity is likely to be lower than diesel. Analysis by GC revealed a number of compounds typically extracted from wood-based tar products. Blends containing 20% and 40% PT with diesel were tested in a 4-cylinder, 4-stoke DI diesel engine. The blends are stable and readily formed. Little difference in engine performance relative to diesel was found for 20% PT blends. PT blends (40%) exhibit significantly higher in-cylinder gas temperature and pressure. Ignition delay for both blends is longer than diesel, as is the fuel burn rate during the premixed stage of the combustion. During the diffusion stage of combustion, the fuel burn rate is lower relative to diesel. The performance of engines fuelled by blends containing 40% or more PT could be improved through optimization of engine systems.

The polyphenols (CPAE II) was isolated from the dichloromethane extract of the pyroligneous acid, Rhizophora apiculata by simultaneous acid base and solvent extraction method. Its qualitative and quantitative composition was studied by gas chromatography mass spectroscopy (GC/MS) and out of 57 peaks, 52 compounds were identified, representing 95.47% of the total polyphenols. The CPAE II was then fractionated to four fractions (F1–F4) by means of thin layer chromatography and silica gel column chromatography with dichloromethane, dichloromethane/chloroform/ethyl acetate mixture (8:1:1; 4:3:3, v/v/v), and ethyl acetate, respectively. The antioxidant properties of the CPAE II and the fractions were evaluated. Among the four fractions, fraction 1 (F1) was the most potent in DPPH radical scavenging activity and molybdenum (VI) reducing power. It was subjected to further purification by means of silica gel column chromatography with hexane, hexane/diethyl ether mixture (9:1, 6:1, 3:1, v/v), and diethyl ether, respectively. 2,6-Dimethoxyphenol (syringol) and dihydroxybenzenes (catechol and 3-methoxycatechol) were isolated and identified by GC/MS, 1H NMR, 13C NMR spectral analyses, and confirmed by GC co-injection with authentic standards. Syringol, catechol and 3-methoxycatechol constitute 39.08, 4.21 and 1.10% of F1, respectively. Their antioxidant activities were evaluated by DPPH radical scavenging activity, ABTS radical cation scavenging activity, phosphomolybdenum and ferric reducing antioxidant power (FRAP). The trend in antioxidant capacity was similar in all the four assays, with dihydroxybenzenes > 2,6-dimethoxyphenols, although discrepancies in the ranking within the dihydroxybenzenes were present. These three compounds which showed significant antioxidant activities were isolated for the first time from the pyroligneous acid, R. apiculata.

Summary The influence of charcoal and smoke condensates (pyroligneous acid, PA) on microbial activity in a highly weathered Amazonian upland soil was assessed via measurements of basal respiration (BR), substrate-induced respiration (SIR), and exponential population increase after substrate addition. PA extracts are commonly used for fertilizer or as pest control in Brazil, where phosphorus (P) availability and nitrogen (N) leaching are among the most severe limitations for agriculture. Microbes play an important role in nutrient cycling and solubilizing of phosphate. BR, microbial biomass, population growth and the microbe's efficiency (expressed by the metabolic quotient) increased linearly and significantly with increasing charcoal concentrations (50, 100 and 150 g kg −1 soil). Application of PA caused a sharp increase in all parameters. We suppose that the condensates from smoke contain easily degradable substances and only small amounts of inhibitory agents, which could be utilized by the microbes for their metabolism.

Total phenolics content, free radical scavenging activity, reducing power, and antioxidant activity of the pyroligenous acid from a mangrove plant, Rhizophora apiculata were evaluated. Dichloromethane extraction of the raw pyroligneous acid successfully yield 2 extracts, i.e. concentrated pyroligneous acid (CPA) and concentrated pyroligneous acid extract (CPAE). Phenolic contents in CPAE and CPA, expressed as (±)-catechin equivalents/g of the sample were 5465 ± 367 mg and 2502 ± 152 mg, and expressed as gallic acid equivalents/g of the sample were 2919 ± 209 mg and 1348 ± 90 mg, respectively. CPAE exhibited superior free radical scavenging activity with EC 50 value = 0.1235 mg/ml, or 80.96% of free radical scavenging capability. The ferric reducing power of CPAE was approximately 3.7, 5.1, 6.1, and 21.3 times higher than that of ascorbic acid, BHA, BHT and alpha-tocopherol. In phosphomolybdenum assay, CPAE showed the greatest antioxidant efficacy ( A 695 = 1.278) compared to those of CPA and different standards. In addition, the free radical scavenging activity, ferric reducing power and total antioxidative activity of CPAE and CPA showed positive correlation with their total phenolic content with R 2 values ranging from 0.9624 to 0.9979.

This paper first aims to evaluate the possibility of synthesizing organic calcium through the use of pyroligneous acid and raw limestone. The factors affecting this reaction were investigated including the particle size of limestone, the type of pyroligneous acid and reaction conditions as well. Secondly, two low-rank coals were mixed with the calcium-enriched pyroligneous acid to evaluate the possibility of desulfurization in the combustion furnace. The soluble calcium within pyroligneous acid is in the form of calcium acetate having a low decomposition temperature around 400 °C, far lower than that of raw limestone being about 700 °C. Due to its solubility, calcium within pyroligneous acid was loaded readily on the coals, forming the ultrafine particles in the impregnated coal matrix. During coal combustion, the loaded calcium underwent quick decomposition prior to char combustion and subsequently, the formed ultrafine calcium oxide captured the evolved sulfur oxide. Around 85% desulfurization efficiency was achieved for coal combustion. S/Ca molar ratio around 1.0 was formed for the particles less than 1.0 μm, whereas it decreased gradually with the increasing particle size.

The usefulness of a mixture of charcoal with pyroligneous acid (MCP) and with barnyard manure (MCB) to improve the medium for bedding plants was evaluated. The basal medium was peat moss, soil, vermiculite, perlite and sand (2:1:1:1:1) (v/v). The MCP or MCB was mixed with the basal medium at 0, 10 or 30% (v/v) and seedlings were transferred to this medium. Both treatments of MCP shortened the number of days to flowering from transplantation of zinnia, melampodium and scarlet sage, increased the survival rate of scarlet sage and zinnia, and raised the quality, such as for melampodium and zinnia. But MCP decreased the quality in a few species because the plant height of French marigold decreased and the plant height and plant spread of scarlet sage decreased with the 30% treatment. MCB increased the survival rate of zinnia with the 10% treatment and tended to improve the quality of all species. We conclude that MCB improves the growth and quality and is effective for the cultivation of bedding plants.

Flash pyrolysis products from hazelnut shell and tea factory waste obtained in a pyrolysis apparatus were analyzed. Comparison of the pyrolytic products of the structural components indicates the origin of each product. A promising route for processing biomass is pyrolytic conversion, which has been conducted under a variety of experimental conditions, resulting in production of charcoal, tarry material, aqueous fraction and gaseous products. Methanol can be produced by pyrolysis of biomass. Methanol mainly arises from methoxyl groups of uronic acid and from the breakdown of methyl esters and/or ethers from decomposition of pectin-like plant materials. Acetic acid comes from the elimination of acetyl groups originally linked to the xylose unit. The pyroligneous acid consists of about 50% methanol, acetone, phenols and water. The yields of acetic acid from hazelnut shell for non-alkali and alkali runs increased from 12.80% to 16.30% and from 16.70% to 22.18% while the final pyrolysis temperature was increased from 675 to 825 K, respectively. The yields of methanol from hazelnut shell for non-alkali and alkali runs increased from 7.26% to 10.30% and from 9.72% to 12.61% while the final pyrolysis temperature was increased from 675 to 875 K, respectively. The maximum yields of acetic acid from tea waste for non-alkali and alkali runs were 7.13% and 9.20% at 825 K, respectively. The maximum yields of methanol from tea waste for non-alkali and alkali runs were 8.82% (at 875 K) and 10.50% (at 925 K), respectively.

Methanol can be used as one possible replacement for conventional gasoline and Diesel fuel. Thermal depolymerization and decomposition of biomass, including cellulose, hemicelluloses and lignin, formed liquid and gaseous products as well as a solid residue of charcoal. A promising route for processing biomass is pyrolytic conversion, which has been conducted under a variety of experimental conditions, resulting in producing charcoal, tarry material, an aqueous fraction and gaseous products. The pyroligneous acid consists of about 50% methanol, acetone, phenols and water. Methanol can be produced by pyrolysis of biomass. Methanol mainly arises from the methoxyl groups of uronic acid and from the breakdown of methyl esters and/or ethers from decomposition of pectin-like plant materials. Acetic acid mainly comes from the acetyl groups of the hemicelluloses.

n/a