Liquefaction Conversion Research Articles

Research progress of biomass fuel upgrading and distributed utilization technology

The study, development and application of biomass energy and alternative petroleum products are effective ways to ensure energy provision, reduce the dependence on fossil energy and resolve the future energy problems. The characteristics of biomass fuel were analyzed, and the upgrading methods of biomass fuels were discussed. Furthermore, the recent technologies of biomass conversion and utilization inland and abroad are reviewed from aspects of direct combustion, biochemical conversion (fermentation and anaerobic digestion), thermal chemical conversion technology (gasification, pyrolysis), liquefaction, compact molding, and supercritical fluid conversion. The application of biomass conversion technologies is presented including biomass gasification to generate electricity, gasification to produce hydrogen, thermal cracking to produce hydrogen, fermentation to produce fuel ethanol, thermal cracking to produce bio-oil, compact molding to produce solid fuel, fermentation of compost to produce fertilizer, anaerobic digestion to produce biogas, catalytic cracking to produce biofuel, and so on. Finally, the development of biomass energy distributed utilization technology is prospected.

Synergistic hydrothermal liquefaction of wheat stalk with homogeneous and heterogeneous catalyst at low temperature

The effect of Na2CO3, Fe and Na2CO3 + Fe during hydrothermal liquefaction (HTL) of wheat stalk with different temperature and reaction time was investigated in this study. The results indicated that Na2CO3 + Fe can promote the cracking of wheat stalk compared with Na2CO3 or Fe. Meanwhile, higher temperature favored the decomposition of wheat stalk and formation of heavy bio-oil. The highest heavy bio-oil yield was 24.25 wt% and the maximum liquefaction conversion rate was 89.45 wt% in system of Na2CO3 + Fe at 270 °C. The analysis results indicated that longer reaction time could promote liquefaction conversion especially for heavy bio-oil with Na2CO3 + Fe during the process of HTL. GC–MS, UPLC-MS and FT-IR analysis indicated that the major organic compounds in heavy bio-oil were aromatic compounds, alcohols, ketones, alkanes, and aldehydes, among of them aromatic compounds were the most prevalent.

Liquefaction of thermal extracts from co-thermal dissolution of a sub-bituminous coal with lignin and reusability of Ni-Mo-S/Al2O3 catalyst

Four thermal dissolution soluble fractions (TDSFs) with different thermal dissolution soluble yields (TDSYs) obtained from thermal and co-thermal dissolutions (CTDs) of a Chinese sub-bituminous Shenfu (SF) coal and lignin were characterized by elemental analysis, FT-IR and synchronous ?uorescence spectrum measurements. The hydro-liquefaction properties of the four TDSFs and SF raw coal with and without catalyst were compared and the recycled use property of the catalyst in hydro-liquefaction of the TDSF from CTD of SF coal and lignin was further probed. The results suggests that the TDSF from the thermal dissolution (TD) of SF coal contained much more amount of aromatic components and polyaromatic hydrocarbons (PAHs) with 4 and more rings than those from the CTD of SF coal and lignin at the same temperature. TDSFs gave much higher liquefaction conversions and oil yields than SF raw coal in hydro-liquefaction with or without catalyst. Almost all TDSF was converted with much high yield of oil and the TDSF from CTD of SF coal and lignin gave higher yield of oil than that from the TD of SF coal in hydro-liquefaction with Ni-Mo-S/Al2O3 catalyst which demonstrated a good reusability in the hydro-liquefaction of TDSF from the CTD of SF coal and lignin. Carbon deposition was hardly observed in the 4 times recycle used catalyst.

Thermal Drying Methods on Coal Liquefaction Conversion

The sample coal used in this work was lignite containing 25% of moisture and 19% of ash from Canada. Drying of lignite coal had considerable influence on the coal liquefaction conversion. Vacuum dried and nitrogen dried samples provided higher conversion than air dried samples. The air drying showed nearly lower conversion, which probably as a result of oxidation. Air Drying seems to add oxidation to form more oxygen functional groups which increases the cross-linking reactions in the early stages of liquefaction. Among three thermal drying methods, vacuum dry provided highest conversion. It was expressed that coal sample with lower amount of moisture revealed higher conversion. Both temperatures and drying times seem to be key variables which impacted coal liquefaction conversion.

Characteristic of low rank coal from Warukin Formation, South Kalimantan and their implication for coal liquefaction

The research was conducted on petrology and geochemistry of coal at Warukin Formation, Barito Basin, in South Kalimantan. Research is focused on composition and behavior of low rank coal toward its liquefaction. The sampling location is in the coal mining of PT. Adaro Indonesia which involves some mining location such as Wara, Tutupan and Paringin area. The sampling was conducted in seam Wara 110, Wara 120, Wara 200, Tutupan 210 and Paringin 712 with ply by ply method. Sample analysis consists of proximate and ultimate properties, composition of maseral, reflectance vitrinite, as well as composition of mineral, major element and organic geochemistry. Experiment of coal liquefaction was conducted on the autoclave with temperature and pressure of 120° C and 14.17 psi. The problems are focusing on influence of maceral, mineralogy and geochemistry low rank coal of Warukin formation in Barito Basin on coal liquefaction, behavior of coal liquefaction to the change in variable of time to result of coal liquefaction yield. The physical and chemical characteristics of coal in Wara seam content are ash (< 7 %) adb, inherent moisture (< 31%) adb, volatile matter (< 5)%) adb and fixed carbon (< 33%) adb. Then in Tutupan and Paringin are ash < 3% adb, inherent moisture < 21% adb, volatile matter < 48% adb and fixed carbon < 40 % adb. Composition element in Wara coal are carbon < 64 % adb, hydrogen < 7 % adb, oxygen < 34% adb and nitrogen < 1% adb, then in Tutupan and Paringin seam consist of carbon (< 65 % adb), hydrogen (< 6 % adb), oxygen (< 32% adb) and nitrogen < 2% adb. The content of maseral in Wara seam coal consist of vitrinite, liptinite, inertinite maseral group which are 81%, 51% and 27% respectively. Result of coal liquefaction on Wara seam with time reaction of 30 minutes is 48.60 % and for 60 minutes is 51.27%. The result of liquefaction is decreasing on reaction time of 90 minutes and 120 minutes, which are 46.72%, 35.51% respectively. The liquefaction conversion obtained from Tutupan and Paringin seam within reaction time 30 minutes and 60 minutes are 8.22% and 15.46% respectively. The conversion is decreasing on reaction time 90 minutes and 120 minutes which of 6.23% and 5.54% respectively. The coal with more lignite is easier to be liquefied than sub-bituminous because the coal has higher hydroxyl group.

Life Cycle Impacts and Techno-economic Implications of Flash Hydrolysis in Algae Processing

Generation of coproducts from nutrients is purported to improve the sustainability of algae-derived transportation fuels by minimizing life cycle impacts and improving economic sustainability. Although algae cultivation produces lipids that is upgraded to drop-in transportation fuel products, life cycle assessment and techno-economic analysis have shown that without coproducts, energy/economic returns are diminishing regardless of processing methods. This study utilizes a combined flash hydrolysis (FH), hydrothermal liquefaction (HTL), and coproduct conversion technology (atmospheric precipitation/AP; hydrothermal mineralization/HTM) to conserve the most recyclable nutrients for coproduct marketability. Six biofuel pathways were developed and compared in terms of “well-to-pump” energy, life cycle greenhouse gas (LC-GHG) emissions, and economic profitability: renewable diesel II (RDII), renewable gasoline (RG), and hydroprocessed renewable jet (HRJ) fuel, each were modeled for AP and HTM coproduct conversi...

Catalytic liquefaction of human feces over Ni-Tm/TiO2 catalyst and the influence of operating conditions on products

In this study, human feces were hydrothermal liquefied and converted into biocrude over Ni-Tm/TiO2 catalyst. The influence of catalysts, reaction temperature, and holding time on the distribution of products and element content of biocrude was assessed. The biocrude yield increased to 53.16% with a reaction temperature of 330 °C, a holding time of 30 min, and adding Ni-Tm/TiO2 catalyst while the liquefaction conversion peaked at 89.61%. The biocrude had an HHV of 36.64 MJ/kg and was similar to heavy crude oil. The biocrude is rich in fatty acid amides, esters, and oxygen-containing-only heteroatom-ring compounds as well as some nitrogen-containing heteroatom-ring compounds. The main gaseous products were CO2, CH4, and C2H6. Hydrothermal liquefaction over Ni-Tm/TiO2 catalyst could be a potential method to handle human excrement treatment and produce biofuel.

Hydrothermal liquefaction of microalgae over transition metal supported TiO2 catalyst

Hydrothermal liquefaction (HTL) of microalgae Nannochloropsis (NAS) over various transition metal M/TiO2 (M = Fe, Co, Ni, Mo, and Mn) was investigated. Ni/TiO2 was the most effective catalyst to improve the yield and quality of biocrude and the liquefaction conversion. Ni/TiO2 was characterized by XRD, XRF, and XPS. The research of Effect of reaction temperature on HTL of NAS over Ni/TiO2 suggested that 300 °C led to a maximum biocrude yield of 48.23% and the highest liquefaction conversion of 89.28%. Adding Ni/TiO2 catalyst reduced the viscosity and provided more light-fraction in biocrude while brought a slight increase in total acid number (TAN). Gas chromatography-mass spectrometry (GC-MS) analysis demonstrated that adding Ni/TiO2 considerably changed the composition of biocrude and the possible pathways were discussed. Reproduction test showed the Ni/TiO2 has an excellent reproduction ability in HTL of NAS.

Effect of solvent and atmosphere on product distribution, hydrogen consumption and coal structural change during preheating stage in direct coal liquefaction

In order to study the necessity of hydrogen source at preheating stage of direct coal liquefaction, product distribution, hydrogen consumption, and coal structural change of Hami sub-bituminous coal (HM) with 1-methylnaphthalene (1-MN) and tetralin respectively were investigated under hydrogen and nitrogen atmosphere. The results show that oil could be generated from coal itself with 1-MN under N2 and the yield increases with temperature rising at the range of 200–350°C, whereas only 4.94% oil is obtained at 350°C. Moreover, volatiles and H/C ratios of pretreated coal decrease dramatically above 250°C. At 350°C, preheating with gas phase H2 in 1-MN promotes oil yield to 10.42%. In the presence of tetralin, oil yields of 28.55% and 26.15% are achieved under N2 and H2 at 350°C, respectively. Approximately same total hydrogen consumption is observed under N2 and H2 with tetralin, and the hydrogen consumption from tetralin is higher than that from H2. With the addition of hydrogen sources, aromaticity of the residual solid decreases and reactivity increases. Decomposition of oxygen-containing functional groups like COOH and CO is not affected by the preheating solvent and atmosphere but relies on temperature. In addition, pretreated solid samples achieve increasing oil yield and conversion in the subsequent liquefaction with their rising thermal reactivity and H/C ratios.

Catalytic liquefaction of municipal sewage sludge over transition metal catalysts in ethanol-water co-solvent

Catalytic liquefaction of (Municipal sewage sludge) MSS over transition metal catalysts in ethanol-water co-solvent (EWCS) was investigated. The effect of operating parameters like temperature, holding time, and ethanol-water ratio was discussed. CuSO4 was selected as the most efficient catalyst. The highest biocrude yield (47.45%) and liquefaction conversion (97.74%) was both obtained at the same conditions following: a reaction temperature of 270°C, a holding time of 30min, an ethanol-water ratio of 1:1, and with CuSO4 as the catalyst. Optimized operating conditions reduced Sulfur and Nitrogen content in biocrude by 55.0% and 14.6%, respectively. The obtained biocrude samples were analyzed and characterized by thermogravimetric analysis (TGA) and gas chromatography-mass spectroscopy (GC-MS), which suggested that adding CuSO4 increased the light-oil like content in biocrude and more than 60% of compounds in biocrude were esters. This process demonstrates the effectiveness of catalytic liquefaction of MSS in EWCS over CuSO4 catalyst.

Biobased polyurethane foam insulation from microwave liquefaction of woody underbrush

Yaupon holly is one of the most widespread woody underbrush species in the southeastern United States, and it can undermine forest health and safety due to its biofuel-like nature during catastrophic wildfires. Yaupon holly was subjected to microwave liquefaction to produce biobased polyurethane (PU) foam insulation. Liquefaction parameters were optimized and summarized as follows: 1) particle size was controlled in the range of 16- to 40- mesh; 2) both the ratios of glycerol to ethylene glycol and liquid to solid were set at 3:1; 3) the reaction process was conducted at 160 °C for 10 min and catalyzed by 1.5% sulfuric acid. The optimal liquefaction conversion yield was 94.9%. The Fourier transform infrared spectra (FTIR) indicated the successful liquefaction and dissolution of wood essential components, i.e. hemicellulose, cellulose, and lignin. The optimal liquefaction product with solid residue was used directly to produce biofoams. With an increased isocyanate index, the thermal insulation properties, mechanical properties, and thermal stability of biofoams increased. Therefore, a promising biobased PU foam was obtained at an isocyanate index of 150. The density, thermal conductivity, Young’s modulus, and compressive stress of the promising biofoam were 18.5 kg·m-3, 0.033 W·m-1·K-1, 176.7 kPa, and 15.4 kPa, respectively.

Experimental investigations on the effect of pyrolytic bio–oil during the liquefaction of Karanja Press Seed Cake

In this study, experimental investigations on the liquefaction of Karanja Press Seed Cake (PSC) were carried out in the presence of Pyrolytic Bio–oil (PBO) produced from the slow pyrolysis of the same feedstock. The effects of PBO amount and temperature were studied with an aim to achieve the highest conversion in liquefaction experiments. Also, comparison has been established between the use of PBO and conventional solvent and acid catalyst such as phenol and sulphuric acid, respectively for achieving the highest liquefaction conversion. A detailed chemical analysis and a comparison of PBO and liquefied product (bio–crude) have been carried out using FT–IR, and GC–MS techniques. The results showed that the Karanja PSC could be directly liquefied in the presence of PBO at moderate reaction conditions. A maximum liquefaction conversion of 99% was obtained at a reaction temperature of 240°C, a residence time of 120 min and a Karanja PSC to PBO ratio of 1:6. In contrast, ∼94% conversion was obtained for the same residence time but at significantly lower temperature of 160°C when phenol and sulphuric acid were used in the ratio of Karanja PSC, phenol and H2SO4 as 1:2:0.6. It was observed that aromatic structure with less oxygen was evident in bio–crude compared to PBO.

Preparation of Biopolyol by Solvolysis Liquefaction of Oil Palm Mesocarp Fibre using Polyhydric Alchohol

Liquefied oil palm mesocarp fibre (LOPMF) is a promising natural material that can be used as biopolyol of polyurethane foam. The aim of this study was to utilizing solvolysis liquefaction conversion technology of oil palm mesocarp fibre (OPMF) for polyurethane (PU) foam. LOPMF was obtained with liquefaction of fibre in polyhydric alchohol (PA) such as ethylene glycol (EG), polyethylene glycol (PEG) and glycerol (GLY) as liquefaction solvent and sulphuric acid (H2SO4) in three different OPMF/PA ratio (1/2, 1/3 and 1/4) in conventional glass reactor. During the liquefaction, cellulose, semi-cellulose and lignin are decomposed, which results in changes of acid value and hydroxyl value. Liquefied OPMF and residues were characterized by Fourier transform infrared (FT-IR) spectroscopy. The results revealed that almost 50% of the OPMF converted into biopolyol product within 2 hours with OPMF/PA ratio of 1/4. Biopolyol produced under different condition showed viscosities from 210 to 450 Pa.s. The hydroxyl and acid values of the liquefied OPMF varied with the liquefied conditions. It was observed that with an increase in the liquefaction solvent (PA) amount in the mixture resulted in a high acid value and hydroxyl value for the OPMF. High reaction temperature combining with low OPMF material to solvent ratio resulted low hydroxyl number of LOPMF. The result in this study showed that biopolyol was suitable monomer for polyurethane synthesis.

Co-liquefaction Behaviour of Elbistan Lignite and Olive Bagasse

In the present study, co-liquefaction potential of Elbistan lignite and Balikesir olive bagasse were investigated by direct coal liquefaction process. The olive bagasse is a cheap and abundant biomass, so it is used to decrease the cost of oil production from the lignite. The effect of blending ratio of the lignite and the olive bagasse on liquefaction conversion and oil yield were investigated. Characterization studies of the starting materials were done using XRD, FTIR, DTA/TG and elemental analysis. Elemental compositions of liquefaction products were also determined and the composition of the obtained oil was identified by GC/MS. DTA and TGA results indicated the synergistic effect of the lignite and the olive bagasse and maximum oil conversion (36 %) was obtained from 1:3 blending ratio of lignite: olive bagasse. The results showed that the obtained oil was paraffinic-low waxy oil with 22.5 MJ/kg of calorific value and 95 g/cm3 density.

Characteristics and Thermal Behaviour of Low Rank Malaysian Coals towards Liquefaction Performance via Thermogravimetric Analysis

In this study, thermal behaviour of two low-rank Malaysian coals namely Mukah Balingian (MB) and Batu Arang (BA) were obtained under pyrolysis conditions via Thermogravimetric analysis (TGA) at a heating rate of 20°C min-1. The thermal characteristics of the coals were investigated prior to direct liquefaction in order to determine the liquefaction performance, i.e. coal conversion and oil yield. The differential weight loss (DTG) results for both coals showed that there are three main stages evolved which consists of moisture, volatile matter and heavier hydrocarbons that correspond to temperature range of 150, 200-500 and 550-800°C, respectively. Apparently, the DTG curves of BA coal reveals a similar pattern of thermal evolution profile in comparison to that of the MB coal. However, the calculated mean reactivity of BA coal is higher than that of MB, which implied that BA would probably enhance coal conversion and oil yield in comparison to MB coal. Interestingly, results showed that under the same liquefaction conditions (i.e. at 4MPa pressure and 420°C), conversion and oil yield of both coals were well correlated with their reactivity and petrofactor value obtained.

Effect of initial coal particle size on coal liquefaction conversion

In coal liquefaction process initial coal particle size can be considered as one of the important process parameters. In this work, particles of coal are prepared by pulverisation and separation into different particle size ranges below 45 to 1,000 µm. Since conventional batch autoclave is not suitable for short contact time experiments, as the time required for the autoclave to reach the reaction temperature can be substantial, the liquefaction runs were investigated with a rapid injection reactor designed specifically for investigating the effect of initial particle size on liquefaction conversion. A Canadian coal was examined in a tubular bomb reactor in presence of tetralin at 400°C for a short reaction time (5 min) with pressure of 6 MPa under nitrogen atmosphere. The results indicated that total conversion obtained during the liquefaction changed according to the different particle size, and optimum particle size (150-212 µm) was detected for the liquefaction condition. [Received: November 27, 2014; Accepted: August 22, 2015]

生物质能的开发与利用技术现状

通过对生物质开发利用技术的研究，结合现有的生物质转化方法，介绍了生物质在固化、液化、气化及生化转化方面的技术特点和研究方法；简述了费托合成技术的不足与改进措施；指出在现有技术下生物质能的发展方向；得出大力发展生物质能技术对能源利用和环境保护具有积极作用。 By researching on development and utilization technology of biomass and combining existing bio- mass converting methods, this paper introduced biomass’s technical characteristics and research methods in biomass-curing, biomass liquefaction, biomass gasification and biochemical conversion of biomass. Moreover, this paper illustrated the disadvantages and improvement measures of Fischer-Tropsch Synthesis, arriving at the biomass energy’s developing direction in current technology. This paper eventually pointed out that it was beneficial to energy using and environmental protection to develop biomass energy technology.

Application and thermal properties of hydrogen-rich bark coal

The thermal properties of hydrogen-rich bark coal were investigated by thermogravimetric analysis, Gieseler fluidity analysis, and polarized light microscopy with a heated stage. The liquefaction behavior was studied separately using an autoclave and a stainless-steel microautoclave reactor. The results showed that the thermal behaviors of hydrogen-rich bark coal are anomalous compared to humic coals, with high fluidities (>180,000ddpm) and intense thermal reaction (the highest mass loss rate is 1.11%/°C). The most interesting temperature range for heating bark coal is 410–450°C: the temperatures of maximum volatile loss of the samples used are in this range, the temperatures of maximum fluidity are about 440°C, and the particle size was drastically reduced on heating to 430°C or above. But in this temperature range, liquefaction conversion values were almost the same, even though oil plus gas yield, and preasphaltene and asphaltene yield were clearly influenced by temperature. Considering the thermal behavior and properties of bark coal, some effective utilization ways are suggested, including low-temperature carbonization, co-coking, direct liquefaction, co-processing, and hydrogen production.

Co-liquefaction behavior of corn straw and Shengli lignite

In this study, the co-pyrolysis and co-liquefaction properties of corn straw (CS) and Shengli lignite (SL) were investigated. Individual liquefaction and co-liquefaction of CS and SL were performed and the characterization of co-liquefaction products was tested. The synergetic effect was discussed. The pyrolysis of SL can be obviously promoted by addition of CS, resulting in the larger weight loss of their blends compared to calculated values of their individual pyrolysis. The individual liquefactions of CS and SL show that CS gives much higher liquefaction conversion than SL at the same liquefaction conditions. During the co-liquefaction of CS and SL, there exists an obviously synergistic effect, which may be attributed to that free radicals or intermediates produced by thermally degradation of CS at low temperature aid the depolymerization of SL, and that the new-formed free radicals or intermediates from co-liquefaction can be easily decomposed and hydrogenated. The characterization of asphaltene and preasphaltene shows that the heteroatom-contained structure in asphaltene and the aliphatic structures in preasphaltene prefer to convert into lighter product compared to individual liquefaction of CS and SL. The largest enhancements in conversion of 8.67% and oil yield of 6.46% were obtained at 4/6 and 6/4 blend ratio of CS/SL among different blends, respectively, with 375 °C temperature, 30 min reaction time and 4 MPa initial pressure.

The Effect of Small Molecular Compounds in Coal on Quick Direct Coal Liquefaction at a High Temperature

The effect of small molecular compounds in coal on quick direct coal liquefaction at high temperature was studied. The results showed that extraction with tetrahydrofuran just removed a portion of organic compounds, which were free or embedded in the macromolecular network structure in coal, without changing the macromolecular network of coal. However, removal of small molecular compounds in coal influenced the pyrolysis behavior and liquefaction performance of coal. The extracted coal exhibited better liquefaction activity in good donor solvent. The liquefaction conversion and yield of oils were higher than that of raw coal. The reason was that extraction with tetrahydrofuran made the relaxation of coal macromolecular network, and increased average pore size of extracted coal, which favored the diffusion of hydrogen-donating solvent into coal macromolecular network, thus increased the probability of collision of radicals and active hydrogen. The quick liquefaction experiment of extracted coal in poor hydrogen-donating solvents showed that the small molecular compounds played an important role as hydrogen donor during the quick liquefaction at high temperature without external active hydrogen resource.