Production of biocrude-oil from swine manure by fast pyrolysis and analysis of its characteristics

All around the world research is being conducted in the field of renewable energy due to the depletion of fossil fuels and the problem of global warming. Fast pyrolysis, an optimal technology for converting biomass to liquid fuel, enables lignocellulosic raw materials such as wood, switch grass and rice straw to be converted to biocrude-oil. Even though many studies on these materials have already been conducted, the high production costs and unstable supply thereof have frequently been pointed out as significant problems. Thus, this study considers the use of another feedstock to solve such disadvantages and to raise the recycling rate of organic wastes simultaneously. Swine manure was selected as an alternative feedstock due to the existence of a stable supply from the livestock farming industry. A bubbling-fluidized-bed reactor was used in the present study for fast pyrolysis. The yield and characteristics of biocrude-oil were investigated at various reaction temperatures. The optimum temperature for maximum biocruce-oil yield was found to be 600 °C with the highest yield of 18.48 wt% and HHV of 13.59 MJ/kg. Due to its low yield and high water content, swine manure is suggested to be blended with other types of biomass as a means of higher yield and quality of biocrude-oil.     

Effects of hot water extraction pretreatment on physicochemical changes of Douglas fir

Hot water extraction (HWE) is an autocatalytic pretreatment that can be effectively integrated into most of the conversion technologies for extracting hemicelluloses from woody biomass. The objective of this study was to understand the influence of pretreatment factors on removal of hemicelluloses from Douglas fir chips. Compositional change in biomass was analyzed with ion chromatography and further confirmed with Fourier transform infrared spectroscopy (FT-IR). Highest hemicellulose extraction yield (HEY) was estimated to be 67.44% at the optimum reaction time (79 min) and temperature (180 °C) by using response surface methodology (RSM). Experimental results show that the HEY increased from 19.29 to 70.81% depending on the reaction time (30–120 min) and the temperature (140–180 °C). Effects of the severity factor (SF) on the mass removal and compositional changes were also evaluated. Hygroscopicity and thermal stability of wood were improved after HWE pretreatment. Colorimetric analysis showed that temperature has a greater influence on color of the wood chips during HWE pretreatment than dwell time. HWE pretreatment shows great potential for extracting hemicelluloses and altering physicochemical properties of wood in an integrated biorefinery for diversification of product portfolio.     

Bio-oil production by fast pyrolysis of cassava residues in a free-fall reactor using liquid media-assisted condensation

We investigated the influence of liquid media-assisted condensation on the bio-oil yield using biomass derived from cassava rhizomes and stalks in a free-fall reactor. Benzene, diesel, engine lubricant, and ethanol were tested as the liquid medium. Exposure times varied from 60 to 120 min with biomass feed rates from 100 to 250 g/h. Engine lubricant and ethanol tended to decrease biomass yield while increasing gas yield. Benzene and diesel showed slightly increased biomass yield. With benzene, the bio-oil water content (28%) was insignificantly different from that without using any condensation substance. However, with diesel, the water content increased very slightly; with engine lubricant, it decreased to 25%; and with ethanol, it significantly decreased to 12%. Also, using diesel generated higher heating values (30 MJ/kg).     

Fast pyrolysis of cellulose in a single pulse shock tube

A shock tube technique was employed to study the thermal decomposition of cellulose in an inert argon gas under the conditions of high temperature, high heating rate, and short reaction times. The influence of temperature and reaction times on product yields and their distribution were investigated. A clean, tar and char free gas consisting mainly of CO, CO₂, C₂H₂, C₂H₄ and CH₄ were produced throughout the course of this investigation. A mass conversion of cellulose to gas exceeding 90 wt% has been realized between the temperatures 700 and 2200°C for the reaction times examined. Carbon monoxide is the major product and attains a yield in excess of 65 wt% for temperatures above 1300°C. Global kinetic parameters for the decomposition of cellulose and its principal gas products were obtained by fitting the experimental data to a single, first order kinetic model. The energy of activation for the decomposition of cellulose was found to be 130.5 kJ/mol. The material balances made for the total mass, carbon and oxygen are good.     

基于逐级裂解气质联用和热重质谱联用技术的杉木热解特性研究

利用逐级裂解气质联用(stepwise Py-GC/MS)和热重质谱联用技术(TG/MS)对杉木的热解特性进行了研究。结果表明,杉木热解主反应温度为250～430℃,随着升温速率的增大,热解起始温度和终止温度均向高温侧移动。对杉木慢速热解过程进行了动力学分析,得到3种升温速率下对应的活化能分别为83.99,88.87,91.98kJ/mol。杉木逐级裂解主要液体产物有乙酸、1-羟基-丙酮、糠醛、雪松醇、左旋葡萄糖和4-羟基-2-甲氧基肉桂醛等,各温度段产物分布各不相同。在杉木慢速热解条件下,左旋葡萄糖发生二次反应,液体产物中存在很多芳香类物质。     

Microalgae as a renewable fuel source: Fast pyrolysis of Scenedesmus sp.

Herein we report the fast pyrolysis of dried, ground Scenedesmus sp. at two different reactor scales. Pyrolysis was performed at 480 °C and 1 bar in both an isothermal spouted bed reactor and a dynamic pyrolysis-GC/MS unit, each with 2 s vapor residence times. Bio-oil products were characterized on the basis of GC-MS, simulated distillation GC, elemental analysis, calorific content and total acid number. The ratio of crude oil: char obtained from the spouted bed reactor was 3.76 by weight, the average calorific content of the oil being 18.4 MJ/kg. The average total acid number (68 mg KOH/g) was lower than typical bio-oil produced via wood pyrolysis. Simulated distillation results indicated that a significant proportion of the oil corresponded to the boiling range typical for heavy gas oil (343 °C–524 °C). Elemental analysis showed the oil contained an average of 27.6 wt.% oxygen and 8.6 wt.% nitrogen, the relatively high nitrogen content being a consequence of the high protein content of the algae. According to GC-MS data, the oil consisted of various hydrocarbons as well as oxygenated and nitrogenous species, including indoles, fatty acids and amides. Pyrolysis-GC-MS was also performed on Scenedesmus sp. in order to provide insights into the nature of the primary pyrolysis products.     

城市固体废弃物典型组分的快速热解产气特性研究

选取城市固体废弃物中的常见六种组分(纸屑、厨余、织物、木屑、塑料、橡胶)作为实验物料进行快速热解实验。在所得实验数据的基础上对热解气体产物的组成以及变化情况进行了分析，并研究了热解混合气的热值随时间变化的情况。通过研究有助于对热解产物进行预测，且能够深入地了解热解机理。     

Distributed production of hydrogen by auto-thermal reforming of fast pyrolysis bio-oil

We demonstrated an auto-thermal reforming process for producing hydrogen from biomass pyrolysis liquids. Using a noble metal catalyst (0.5% Pt/Al₂O₃ from BASF) at a methane-equivalent space velocity of around 2000 h⁻¹, a reformer temperature of 800 °C–850 °C, a steam-to-carbon ratio of 2.8–4.0, and an oxygen-to-carbon ratio of 0.9–1.1, we produced 9–11 g of hydrogen per 100 g of fast pyrolysis bio-oil, which corresponds to 70%–83% of the stoichiometric potential. The elemental composition of bio-oil and the bio-oil carbon-to-gas conversion, which ranged from 70% to 89%, had the most significant impact on the yield of hydrogen. Because of incomplete volatility the remaining 11%–30% of bio-oil carbon formed deposits in the evaporator. Assuming the same process efficiency as that in the laboratory unit, the cost of hydrogen production in a 1500 kg/day plant was estimated at $4.26/kg with the feedstock, fast pyrolysis bio-oil, contributing 56.3% of the production cost.     

Production of hydrogen by lignins fast pyrolysis

This paper reports the results of experiments performed on the flash pyrolysis of lignin samples submitted to controlled heat flux densities (short flashes of a concentrated radiation). Two types of lignins are used: Kraft and Organocell lignins. Microscopic observations of the reacted samples reveal the formation of an intermediate liquid compound that precedes the further formation of char, vapours and gases. The rates of mass loss and the production rates of the products are determined for both lignins. The results are compared to each other and to those obtained in former similar studies made with cellulose.

The analyses of the produced gases reveal high syngas and H₂ contents (respectively 87 and 50 mol%). This composition is compared to results obtained in other different thermal conditions with lignins and other types of biomasses. The possible mechanism of hydrogen formation is further discussed.     

Gravity separation of oil shale and low-temperature pyrolysis characteristics of different density fractions

In this paper, gravity separation of Huadian? (HD) and Longkou? (LK) oil shales and low-temperature pyrolysis characteristics of their different density fractions have been studied. The gravity separation results showed that kerogen could be enriched using the gravity separation method. The low-temperature pyrolysis results showed that the highest oil contents of HD and LK were in the density fractions of 1.4–1.5 and 1.5–1.6 g·cm^?3, respectively. Meanwhile, for the low-temperature pyrolysis, the oil/gas ratio decreased with the density increase, indicating higher gas loss and lower oil yield with the increase of density. The mineralogical analysis showed that most of the organic matter were associated with clay minerals, and the organic matter could not fully liberate from the matrix under coarse particles. The migration and occurrence of minerals and organic matter in different density fractions generated various pyrolysis characteristics.     

Selective pyrolysis of paper mill sludge by using pretreatment processes to enhance the quality of bio-oil and biochar products

Paper mill sludge (PMS) is a residual biomass that is generated at paper mills in large quantities. Currently, PMS is commonly disposed in landfills, which causes environmental issues through chemical leaching and greenhouse gas production. In this research, we are exploring the potential of fast pyrolysis process for converting PMS into useful bio-oil and biochar products. We demonstrate that by subjecting PMS to a combination of acid hydrolysis and torrefaction pre-treatment processes it is possible to alter the physicochemical properties and composition of the feedstock material. Fast pyrolysis of pretreated PMS produced bio-oil with significantly higher selectivity to levoglucosenone and significantly reduced the amount of ketone, aldehyde, and organic acid components. Pretreatment of PMS with combined 4% mass fraction phosphoric acid hydrolysis and 220 °C torrefaction processed prior to fast pyrolysis resulted in a 17 times increase of relative selectivity towards levoglucosenone in bio-oil product along with a reduction of acids, ketones, and aldehydes combined from 21 % to 11 %. Biochar, produced in higher yield, has characteristics that potentially make the solid byproduct ideal for soil amendment agent or sorbent material. This work reveals a promising process system to convert PMS waste into useful bio-based products. More in-depth research is required to gather more data information for assessing the economic and sustainability aspects of the process.     

Effects of ash removal by agitated aqueous washing and sedimentation on the physico-chemical characteristics and fast pyrolysis of trommel fines

A pre-treated trommel fines feedstock (DPT) with 35.1 wt% ash content and particle size range of 0.5–2 mm was processed through two (100% distilled water and 1% surfactant in distilled water) aqueous agitated washing and sedimentation procedures for ash reduction prior to fast pyrolysis in a bubbling fluidized bed reactor. The washing process led to more than 36% reduction in the ash/inorganic contents of the DPT feedstock and yielded about 78 wt% of organic-rich feedstocks denoted as WPT1 and WPT2. Characterisation and fast pyrolysis of all three feedstocks was carried out to evaluate the effect of the washing process on their physico-chemical characteristics and yields of fast pyrolysis products. Results showed that the ash reduction led to increase in the volatile matter contents of the washed feedstocks by 20%, while reducing nitrogen contents. In addition, fast pyrolysis of the feedstocks showed improved yield of liquid and gas products, with a dramatic reduction of reaction water, indicating that the ash removal reduced the catalytic effect of the ash on water formation during the fast pyrolysis process. The major organic compounds in the liquid products included phenols and furans from biogenic fraction of the feedstock as well as aromatic hydrocarbons such as those obtained from pyrolysis of plastics. More importantly, the overall energy yields from the fast pyrolysis process increased by over 35% after washing the feedstock, with washing with only distilled water alone giving the highest energy yield of 93%. Hence, coupling the water-washing ash reduction process with fast pyrolysis appeared to be a suitable technology for valorising feedstocks with high ash contents such as trommel fines for energy and chemicals.     

块状废轮胎固定床热解特性实验研究

国内外对于废旧轮胎热解的研究大多集中在对轮胎小颗粒的探索上,对于破碎成本较低的大块状轮胎的热解较少有人涉及.为了探究块状轮胎的热解特性,文章在外热式固定床热解炉上进行了不同热解温度下块状废轮胎热解特性的实验研究.结果表明:块状废轮胎热解产生的燃气成分主要为CH4,H2以及大分子烃类CnHm,且其燃气产率随热解温度的升高而增加.当热解温度高于550℃时,热解产物CnHm有二次裂解现象,热解产生的燃气具有较高热值;热解温度为600℃时,燃气热值可以达到26 MJ/m3;随着热解温度的提高,热解炭中挥发分含量减少,固定碳含量略有增加,热解温度对热解油及热解气产率影响明显.与小颗粒轮胎相比,块状轮胎热解气中小分子气体CH4,H2等含量相对较少,而大分子烃类含量相对较多.热解产物产率方面,热解炭和热解气的产率更大,焦油产率降低.     

Fast and catalytic pyrolysis of xylan: Effects of temperature and M/HZSM-5 (M= Fe,Zn) catalysts on pyrolytic products

Pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) was employed to achieve fast pyrolysis of xylan and on-line analysis of pyrolysis vapors. Tests were conducted to investigate the effects of temperature on pyrolytic products, and to reveal the effect of HZSM-5 and M/HZSM-5 (M= Fe, Zn) zeolites on pyrolysis vapors. The results showed that the total yield of pyrolytic products first increased and then decreased with the increase of temperature from 350°C to 900°C. The pyrolytic products were complex, and the most abundant products included hydroxyacetaldehyde, acetic acid, 1-hydroxy-2-propanone, 1-hydroxy-2-butanone and furfural. Catalytic cracking of pyrolysis vapors with HZSM-5 and M/HZSM-5 (M= Fe, Zn) catalysts significantly altered the product distribution. Oxygen-containing compounds were reduced considerably, and meanwhile, a lot of hydrocarbons, mainly toluene and xylenes, were formed. M/HZSM-5 catalysts were more effective than HZSM-5 in reducing the oxygen-containing compounds, and therefore, they helped to produce higher contents of hydrocarbons than HZSM-5.     

Catalytic fast pyrolysis of pressure-sensitive adhesives wastes using Py-GC/MS

Catalytic fast pyrolysis of pressure-sensitive adhesives (PSAs) wastes was tested by Py-GC/MS for potential preparation of fuels from PSAs wastes. The effects of ZSM-5 and the ash from the combustion of PSAs on the compositions of the condensable and incondensable products were investigated. It was found that the oxygen content in the condensable product is reduced with more generated aromatics over ZSM-5. Ash presented positive effects on the upgrading of incondensable products with a favorable H₂/CO ratio of 2 and a higher caloric value. Reaction routes of chain aliphaticcompounds under the catalysis of ZSM-5 and ash were respectively proposed.     

Effect of temperature on the fast pyrolysis of organic-acid leached pinewood; the potential of low temperature pyrolysis

In this paper, we have evaluated the potential of organic acid (mixture of acetic, formic and propionic acid) leaching of biomass and subsequent fast pyrolysis to increase the organic oil, sugars and phenols yield by varying the fluidized bed temperature between 360 °C and 580 °C (360 °C, 430 °C, 480 °C, 530 °C, and 580 °C). The pyrolysis of acid leached pinewood resulted in more organic oil and less water and residue compared to untreated pinewood over the whole temperature range. Below 500 °C the difference was most profound; for acid leached pinewood at 360 °C the organic oil was already 650 g kg⁻¹ pine with a sugar yield of 230 g kg⁻¹ pine. At this low pyrolysis temperature no bed agglomeration was observed for acid leached pine whereas at the higher temperatures tested agglomerates were found, which were identified to be clusters of fluidization sand glued together by sticky pyrolysis products (melt). Low reactor temperatures also favored the production of monomeric phenols, though their absolute yields remained low for both untreated and leached pine (maximum: 23 g kg⁻¹ pine, 80 g kg⁻¹ lignin). GPC, GC/MS and UV-fluorescence spectroscopy showed that acid leaching did not influence significantly the yield and molecular size of the aromatic fraction in the produced pyrolysis oils. Back impregnation of the removed AAEMs into leached biomass revealed that the effects of the applied acid leaching, both with respect to the product yields and bed agglomeration, can be mainly assigned to the removal of AAEMs.     

Catalytic fast pyrolysis of sugarcane bagasse pith with HZSM-5 catalyst using tandem micro-reactor-GC-MS

Fast pyrolysis of biomass is praised as an efficient and feasible process to selectively convert lignocellulosic biomass into bio-fuels and bio-chemicals. Pith of sugarcane bagasse could be an attractive lignocellulosic waste from depithing process from pulp and paper mill, which can utilize for production of biofuel and added value products. In this study, we employed a tandem micro-reactor coupled with gas chromatography-mass spectroscopy to investigate the products distribution from pith of sugarcane bagasse via catalytic fast pyrolysis. In the operating conditions, pyrolysis temperature and HZSM-5 catalyst had significant effect on products and distributions. An increase in the pyrolysis temperature from 400°C to 550°C led to an increase in the yield of phenolic compounds (6.3%, w/w%), followed decrease at higher temperature. The maximum carboxylic acids (10.6%) and furfural (3.5%) were obtained at lower temperature. At presence of HZSM-5 catalyst, the selectivity of aromatics such as benzene, toluene, indene, and naphthalene were improved.     

Bio‐oil production from rapid pyrolysis of cottonseed cake: product yields and compositions

Fixed‐bed fast pyrolysis experiments have been conducted on a sample of cottonseed cake to determine the effects of pyrolysis temperature, heating rate and sweep gas flow rate on pyrolysis yields and chemical compositions of the product oil. The liquid products and the subfractions of pentane soluble part were characterized by elemental analysis, FT‐IR spectroscopy, ¹H‐NMR spectroscopy and pentane subfraction was analysed by gas chromatography. The maximum oil yield of 34.8% was obtained at final temperature of 550°C with a heating rate of 700°C min^?1 and nitrogen flow rate of 100 cm³ min^?1. Chromatographic and spectroscopic studies on bio‐oil have shown that the oils obtained from cottonseed cake can be used as a renewable fuel and chemical feedstock. Copyright © 2005 John Wiley & Sons, Ltd.     

Manipulation of chemical species in bio-oil using in situ catalytic fast pyrolysis in both a bench-scale fluidized bed pyrolyzer and micropyrolyzer

In situ catalytic fast pyrolysis (CFP) of biomass was conducted with base or acid catalysts in a bench-scale fluidized bed pyrolyzer. Complete mass balances were performed, allowing for quantitatively investigating the catalytic impacts on the final bio-oil composition. Acidic catalysts exhibited relatively higher activities for decomposition of sugar and pyrolytic lignin, dehydration, decarbonylation, and coke formation, as relative to base catalysts. Carbon balances revealed that a significant amount of carbon in bio-oil was transformed to coke during CFP. Due to the decrease in the bio-oil yield during CFP, significantly less energy was recovered in CFP products than in control fast pyrolysis products. CFP was also performed in micropyrolyzer and the results were compared with those in the bench-scale reactor to determine the consistency across the experimental systems. Different from the bench-scale pyrolyzer, the basic catalyst more strongly influenced the micropyrolyzer products and the discrepancies suggest a more rapid deactivation of the basic catalyst.     

Producing Bio-oil from Olive Cake by Fast Pyrolysis

Abstract

This article reports on physico-chemical properties of olive cakes to evaluate them as a raw material in energy production through thermo-chemical pyrolysis conversion process. The present study focuses on the actions related to the possibilities to utilize in particularly olive cake as an agricultural residue. Olive cake is a very promising material for the production of bio-oil. Liquid, solid, and gaseous products were obtained from olive cake by pyrolysis. If the purpose were to maximize the yield of liquid products resulting from biomass pyrolysis, a low temperature, high heating rate, and short gas residence time process would be required. Flash pyrolysis gives high oil yields. The heating was carried out from 298 K to 1,050 K in the absence of oxygen. The yields of liquid products were obtained from the olive cake by pyrolysis for the runs of different heating rates: 10 K/s, 20 K/s, and 40 K/s. The highest bio-oil yields from the olive cakes were 31.0% at 700 K, 36.0% at 700 K, and 41.0% at 700 K obtained from 10 K/s, 20 K/s, and 40 K/s heating rate runs, respectively. The highest bio-oil yields olive stone shells were 27.0% at 700 K, 31.0% at 700 K, and 34.5% at 750 K obtained from 10 K/s, 20 K/s, and 40 K/s heating rate runs, respectively.