Liquefaction Conversion Research Articles

ADVANCING SUSTAINABLE RESOURCE UTILISATION: A REVIEW OF AQUATIC BIOREFINERIES

This review explores the transformative potential of aquatic biorefineries in advancing sustainable resource utilisation. As global demands for renewable resources intensify, biorefineries have emerged as versatile solutions. Focusing on aquatic environments, this paper delves into diverse biomass resources, encompassing microorganisms, algae and aquatic plants. It navigates through key biorefinery processes, including hydrothermal liquefaction, algae cultivation and enzymatic conversion, illuminating their roles in sustainable biofuel and high-value chemical production. Thermochemical conversion processes, such as pyrolysis and gasification, offer additional pathways for bio-based product generation. The review critically assesses challenges in these processes, ranging from technical intricacies to regulatory considerations. Examining products derived from aquatic biorefineries (i.e. biofuels, chemicals and biomaterials) underscores their versatility. Looking ahead, the paper identifies technical challenges, regulatory landscapes and emerging technologies as focal points for future research. The review concludes by envisioning aquatic biorefineries as key players in sustainable resource management, advocating for research and technological innovation to propel this transformative field into the mainstream of the bio-based economy.

Trilogy of comprehensive treatment of kitchen waste by bacteria-microalgae-fungi combined system: Pretreatment, water purification and resource utilization, and biomass harvesting

Given its profound disservice, a bacteria-microalgae-fungi combined system was designed to treat kitchen waste. Firstly, a new type of microbial agent homemade compound microorganisms (HCM) (composed of Serratia marcescens, Bacillus subtilis and other 11 strains) with relatively high bio-security were developed for pretreating kitchen waste, and HCM efficiently degraded 85.2 % cellulose, 94.3 % starch, and 59.0 % oil. HCM also accomplished brilliantly the initial nutrients purification and liquefaction conversion of kitchen waste. Under mono-culture mode (fungi and microalgae were inoculated separately in the pre - and post-stages) and co-culture mode (fungi and microalgae were inoculated simultaneously in the early stage), microalgae-fungi consortia were then applied for further water purification and resource utilization of kitchen waste liquefied liquid (KWLL) produced in the pretreatment stage. Two kinds of microalgae-fungi consortia (Chlorella sp. HQ and Chlorella sp. MHQ2 form consortia with pellet-forming fungi Aspergillus niger HW8–1, respectively) removed 79.5–83.0 % chemical oxygen demand (COD), 44.0–56.5 % total nitrogen (TN), 90.3–96.4 % total phosphorus (TP), and 64.9–71.0 % NH4+-N of KWLL. What's more, the microalgae-fungi consortia constructed in this study accumulated abundant high-value substances at the same time of efficiently purifying KWLL. Finally, in the biomass harvesting stage, pellet-forming fungi efficiently harvested 81.9–82.1 % of microalgal biomass in a low-cost manner through exopolysaccharides adhesion, surface proteins interaction and charge neutralization. Compared with conventional microalgae-bacteria symbiosis system, the constructed bacteria-microalgae-fungi new-type combined system achieves the triple purpose of efficient purification, resource utilization, and biomass recovery on raw kitchen waste through the trilogy strategy, providing momentous technical references and more treatment systems selection for future kitchen waste treatment.

Comparative energy and exergy analysis of ortho-para hydrogen and non-ortho-para hydrogen conversion in hydrogen liquefaction

This study reports the comparative energy and exergy analysis of ortho-para hydrogen and non-ortho-para hydrogen conversion in hydrogen liquefaction process. Two cases were simulated, case A – hydrogen liquefaction with ortho-parahydrogen conversion and case B – hydrogen liquefaction without ortho-parahydrogen conversion. This is the first study that presents a comparative energy and exergy analysis between such two cases. In this research, a hydrogen liquefaction process was designed adopting cascaded five-stage Brayton refrigeration cycle. The process was simulated in Aspen PLUS. The process used a mixed refrigerant (of liquefied natural gas) refrigeration cycle to precool the gaseous hydrogen feed from 26 °C temperature to −192 °C temperature, and mixed refrigerant (of nelium) was subsequently used to further deep-cool the the hydrogen stream from −192 °C temperature to −245.99 °C temperature in the cryogenic section of the process. Liquefaction was achieved by expanding the hydrogen through Joule-Thomson valve at −248.37 °C and 1 bar. The simulated results of the two cases showed the specific energy consumption of case A to be 8.45 kWhr/kgLH, and that of case B to be 15.65 kWhr/kgLH respectively. The results also indicated a total exergy efficiency of 92.42% in case A and 87.18% in case B. The research results showed that the hydrogen liquefaction designed with configuration of ortho-parahydrogen conversion has better performance indicators than the liquefaction without ortho-parahydrogen conversion. Therefore, hydrogen liquefaction with ortho-parahydrogen conversion can be considered in the design and development of new hydrogen liquefaction plants. Process optimization is recommended to further enhance the specific energy consumption and exergy efficiency of both processes.

Recent Advances of Solvent Effects in Biomass Liquefaction Conversion

Liquefaction conversion technology has become one of the hottest biomass conversion methods due to its flexible material selection and extensive product applications. Exploring biomass liquefaction conversion focuses on catalysts, biomass/water ratio, and reaction temperature. However, it is found that solvents are crucial in the biomass liquefaction process and significantly impact the type of liquefied products and bio-oil yield. Given the current rapid development trend, timely sorting and summary of the solvent effect in the biomass liquefaction process can promote the subsequent development and industrialization of more efficient and cleaner biomass liquefaction technology. Therefore, this review first introduces the characteristics of water as the liquefaction solvent, then summarizes the effects of organic solvents on liquefaction, and finally elaborates on the synergistic effect of co-solvents, which provides a more systematic overview of solvent effects in the liquefaction process. Meanwhile, prospects are put forward for the future development of biomass liquefaction conversion.

Direct Liquefaction of South African Vitrinite- and Inertinite-Rich Coal Fines.

In this investigation, coal fines enriched with inertinite were used for direct liquefaction experiments. For comparison, a vitrinite-rich coal typically utilized in coal-to-liquid processes was also employed. To assess the impact of mineral matter content, demineralization was used to remove most of the inorganic constituents. The findings revealed that the inertinite-rich coal exhibited lower liquefaction conversions due to a reduced proportion of reactive macerals and elevated levels of inorganic mineral matter. These conversion values exhibited a strong correlation with the quantity of reactive macerals present in the parent coals. For the inertinite-rich coal, the presence of inorganic mineral matter impeded the liquefaction process but facilitated the CO2 gasification reactions of the derived chars. To evaluate their potential in gasification processes, CO2 gasification experiments were conducted and the reactivities and apparent gasification activation energies of both coal chars, liquefaction residue chars, and preasphaltene and asphaltene (PAA) chars were calculated. These calculations were carried out using the random pore model (RPM) and volumetric reaction model (VRM). The chemistry, reactivity, and kinetics of residue gasification conversion are not thoroughly understood, yet they hold significant importance in optimizing syngas production within gasification processes. The findings from this work highlight significant differences in liquefaction conversion values, product distribution, and composition. These differences are influenced by factors such as maceral composition, inorganic mineral matter content, hydrogen-donor capabilities of the solvent, and liquefaction reaction temperatures. Additionally, these variables affect the CO2 gasification reactivity of liquefaction solid residue chars.

Catalytic hydrothermal liquefaction of Camelina sativa residues for renewable biogasoline production

ABSTRACT Camelina sativa plant residue was used as feedstock for the production of biogasoline (a mixture of paraffinic and olefinic hydrocarbons) by catalytic hydrothermal liquefaction (cHTL) process. The experiments were conducted at temperature range 200–375°C and pressure range 10–19 MPa. Molecular hydrogen was added for the hydro-deoxygenation processes. Various experiments were performed to understand the contributions of process parameters such as temperature, pressure, hydrogen, and retention time on reaction conversion and products distribution. This was followed by screening of different catalyst supports – γ-Al2O3, HZSM-5, SiO2-Al2O3, SBA-15, and Al2O3-HZSM-5 to understand their impacts as well as catalytic activities. The Al2O3/HZSM-5 exhibited the best properties and was impregnated with a varying range of cobalt metal for the HTL of Camelina sativa. The 5%Co/γ-Al2O3-HZSM-5 catalyst exhibited highest liquefaction conversion (79%) and biogasoline yield (43%) at optimized reaction conditions due to the presence of strong brønsted acidity on the catalyst were that enhanced both the hydrocarbon cracking and hydrogenation leading to the production of low boiling point and low molecular weight hydrocarbon within the boiling point range of fossil gasoline. Across all the data point used in the work, the average deviation was within ± 3%, these are mostly indicated by the error bars.

Experimental and numerical study on the offshore adaptability of new FLH2 floating hydrogen liquefaction production storage and offloading unit

With the development of hydrogen production technology from offshore wind power and natural gas, the deep-sea energy interconnection system using hydrogen energy as the medium is constantly improving. The floating hydrogen liquefaction production storage and offloading unit (LH2-FPSO, FLH2) is an effective method for large-scale utilization of offshore hydrogen energy. By filling the heat exchanger with ortho-parahydrogen conversion catalyst, a new porous medium heat exchange channel is formed. Integrating the spiral wound heat exchanger with the ortho-parahydrogen catalytic conversion reactor can reduce the deck area of FLH2 process system and lower the investment cost of floating hydrogen liquefaction device. The performance of FLH2 can be influenced by the offshore wave and typhoon. In this paper, the methods of floating cryogenic visualization experiment, theoretical analysis and numerical simulation are conducted to study the coupled flow and heat transfer mechanism of working fluid applied in FLH2 under offshore conditions. The results show that the sea state has little influence on the ortho-parahydrogen conversion and cooling process of hydrogen in the porous heat exchange tube. The complex flow and heat transfer challenges brought by the integrated process of new floating hydrogen liquefaction and ortho-parahydrogen conversion have been overcome. With the effect of co-current shear of gas-phase mixed refrigerant, a large dry area will not appear on the outer wall surface of porous tube under offshore conditions. The FLH2 process system shows good adaptability at sea.

High-efficiency co-liquefaction of low-rank coal and PAEs-rich PVC waste in supercritical water: Products upgrading and dechlorination

With the extensive use of phthalates (PAEs)-rich polyvinyl chloride (PVC) plastic products, the recycling of PAEs-rich PVC waste has become a great challenge. Meanwhile, the efficient utilization of low-rank coal is important in China due to the abundant reserves. In this study, a high-efficiency co-liquefaction treatment of PAEs-rich PVC waste and low-rank coal (Inner Mongolia lignite) was developed by using supercritical water (SCW) process based on the interaction between the two kinds of waste. The effects of temperature, time, solid-to-liquid ratio (MCoal+PVC:MH2O), and mass ratio of coal-to-PVC (MCoal:MPVC) on the co-liquefaction conversion, composition of liquefied oil and dechlorination of PVC waste were investigated. The co-liquefaction of low-rank coal and PAEs-rich PVC waste had a significant positive synergistic effect with a maximum synergistic efficiency of 7.53% in the temperature range of 350–450 °C. The conversion ratio of low-rank coal and PAEs-rich PVC waste by SCW co-liquefaction increased from 59.71% to 74.92% with the increase of reaction temperature from 350 to 450 °C. PAEs-rich PVC waste could be almost completely dechlorinated (>98%) by the SCW co-liquefaction process, and more than 90% of the DEHP could be decomposed. The addition of PAEs-rich PVC waste resulted in a significant decrease of the percentage of heteroatom-containing compounds in the oil products by the co-liquefaction. At 450 °C, the co-liquefaction oil contained 69.16% of hydrocarbons and 6.14% of phenolic compounds. Different from supercritical water gasification, the purpose of SCW co-liquefaction in this study is to improve the coal liquefaction conversion ratio and oil quality by introducing the PAEs-rich PVC waste. The synergistic SCW treatment of PAEs-rich PVC waste and low-rank coal has good application prospects in products upgrading of low-rank coal and safe recycling of PAEs-rich PVC waste plastics.

Roles of major alloying elements in steels and alloys on corrosion under biomass hydrothermal liquefaction (HTL) conversion

Hydrothermal liquefaction (HTL) is a promising thermochemical technology to convert wet biomass and biowaste streams into bioenergy products. Significant knowledge gaps exist due to reactors’ corrosion damage. This study investigated the roles of alloying elements (Cr, Fe, Ni and Mo) on corrosion in simulated HTL environments via thermodynamic calculation and autoclave tests. Cr acts as the dominant alloying element, and the tested Fe-based steels and Ni-based alloys with Cr content over about 16% exhibit satisfied resistance to the HTL environments. Influences of alloying elements Ni and Mo are different depending on Cr content in the steels and alloys.

Seaweed Pellets as a Renewable Fuel Feedstock

Seaweed can be a desirable source of renewable energy or fuel after it has been processed by combustion, thermochemical conversion by gasification, pyrolysis, or hydrothermal liquefaction (HTL) or biochemical conversion routes like anaerobic digestion (AD). This work explores how well the measured properties of seaweed pellets match the specifications for the various fuel and energy conversion options listed. Blends of hay, wood chips, sawdust, and seaweed were pelletized. Eight pellet blends with dominant seaweed content and minimum acceptable mechanical strength and stability were produced and their physical and chemical properties were reported. The seaweed pellets had an energy content of around 14 MJ/kg, and each pellet could withstand almost 200 N of compression force. Their water content was around 5% or less and their ash content was around 20–34%. According to the results, a higher wood content increased the energy content of the pellets. Among those properties measured in this project, none of them contradicted the typical specifications of combustion, HTL, and AD. However, the low water content and low strength of some pellet types were unable to meet the specifications for certain types of gasification and pyrolysis.

Optimization of process parameters at direct liquefaction of waste PETs

Waste polyethylene terephthalate (wPET) was converted to liquid fuel by direct liquefaction method. Additionally, how the catalyst (sodium borohydride) and microwave pre-treatment affect the total conversion and the char yield were investigated. Direct liquefaction experiments were carried out in a batch reactor under non-catalytic/catalytic conditions, and reaction temperature of 325–425 °C, and solid/solvent ratio of ¼, and reaction time of 15–90 min, and microwave pre-treatment time of 3–10 min, and an initial nitrogen pressure of 20 bar. Both the microwave pre-treatment and sodium borohydride (NaBH4) increased the total conversion in the direct liquefaction of wPETs. According to fourier transform infrared spectroscopy (FTIR) and X-Ray diffraction (XRD) analysis of char samples obtained in the direct liquefaction process, the NaBH4 was converted to sodium borate (Na2B8O13). NaBH4 made both hydrogen (H) donating and catalytic effect. The highest total conversion in direct liquefaction of wPETs, which has at the reaction time of 30 min, and the reaction temperature of 400 °C, and in presence of NaBH4, and the microwave pre-treatment of 3 and 8 min, was 62%. The optimum process parameters in direct liquefaction of wPETs are the reaction time of 30 min, and reaction temperature of 400 °C, and the microwave pre-treatment time of 3 min.

Impacts of catalyst, inorganic and organic corrodants on corrosion under batch-mode catalytic biomass hydrothermal liquefaction conversion

Catalytic hydrothermal liquefaction (CHTL) is used to convert wet biomass for highly promising carbon conversion efficiency. This study investigated three major environmental factors, including catalyst, inorganic corrodants and organic acid on the corrosion of two candidate reactor steels (SS310 and P91) using autoclave methodology and advanced characterization techniques. The addition of 0.5 M K2CO3 resulted in a remarkable increase in corrosion rates and significantly changed the corrosion layers formed. The acetic acid generated from CHTL also noticeably enhanced corrosion while the presence of Cl- and S2- only had marginable influence. SS310 exhibited much better performance than P91 under the CHTL conditions.

Biocrude Oil Production by Integrating Microalgae Polyculture and Wastewater Treatment: Novel Proposal on the Use of Deep Water-Depth Polyculture of Mixotrophic Microalgae

Microalgae have attracted significant attention worldwide as one of the most promising feedstock fossil fuel alternatives. However, there are a few challenges for algal fuels to compete with fossil fuels that need to be addressed. Therefore, this study reviews the R&D status of microalgae-based polyculture and biocrude oil production, along with wastewater treatment. Mixotrophic algae are free to some extent from light restrictions using organic matter and have the ability to grow well even in deep water-depth cultivation. It is proposed that integrating the mixotrophic microalgae polyculture and wastewater treatment process is the most promising and harmonizing means to simultaneously increase capacities of microalgae biomass production and wastewater treatment with a low land footprint and high robustness to perturbations. A large amount of mixotrophic algae biomass is harvested, concentrated, and dewatered by combining highly efficient sedimentation through flocculation and energy efficient filtration, which reduce the carbon footprint for algae fuel production and coincide with the subsequent hydrothermal liquefaction (HTL) conversion. HTL products are obtained with a relatively low carbon footprint and separated into biocrude oil, solid, aqueous, and gas fractions. Algae biomass feedstock-based HTL conversion has a high biocrude oil yield and quality available for existing oil refineries; it also has a bioavailability of the recycled nitrogen and phosphorus from the aqueous phase of algae community HTL. The HTL biocrude oil represents higher sustainability than conventional liquid fuels and other biofuels for the combination of greenhouse gas (GHG) and energy return on investment (EROI). Deep water-depth polyculture of mixotrophic microalgae using sewage has a high potential to produce sustainable biocrude oil within the land area of existing sewage treatment plants in Japan to fulfill imported crude oil.

EFFECT of surface treatment on corrosion control of P91 hydrothermal aqueous solutions

ABSTRACT The proven efficacy of surface treatment on ferritic-martensitic (F/M) steels in subcritical and supercritical water environments has spawned interest in its application for the construction of biomass hydrothermal liquefaction (HTL) conversion reactors. The objective of this paper is to determine the relative extent to which well-established surface treatments, including mechanical abrasion (baseline), sandblasting, shot peening, and pickling, affect corrosion of the steels in a simulated HTL biomass conversion environment. These treatments were administered to P91 steel for the purpose of improving corrosion resistance towards that exhibited by Type 304 austenitic stainless steel. Samples were immersed in a simulated HTL conversion environment at 310 °C and 10 MPa for 10 days using a static autoclave testing system. None of the surface treatments administered improved corrosion control of P91. The structure and chemistry of the oxide scale formed during immersion were not altered by the surface treatments administered, i/e., none of which promoted of the formation of a more protective Cr-enriched scale. Shot peening was particularly problematic as it promoted the formation of Cr-rich carbides in the near-surface region, which, when incorporated into the oxide scale that formed during high temperature immersion, served to reduce the amount Cr available for oxidization.

Bibliometric analysis of research trends on the thermochemical conversion of plastics during 1990–2020

The aim of this bibliometric analysis was to evaluate the trends in literature and the impact of publications that have been published during the period 1990–2020, in the field of thermochemical conversion of plastics, namely gasification, liquefaction and pyrolysis. SCOPUS was used and data was vetted via MS Excel, with analysis being completed via MS Excel and VOSViewer. A total of 1705 publications were used in the study, and China was identified as the most productive country. Pyrolysis was the most researched technology with over 88% of publications, while liquefaction accounted for less than 3% of the total publications. Across all three technologies, polyethylene (PE) was the most commonly occurring type of plastic. Journal of Analytical and Applied Pyrolysis had the highest number of publications and total citations. However, Energy Conversion and Management had a higher impact factor and higher average citations per publication. University of Alicante was identified as the most productive university with a total of 45 publications, while University of Leeds was the most commonly cited with an average of 65 citations per publication. The keyword analysis showed that co-pyrolysis with biomass and catalytic pyrolysis are gaining increased interests.

Cleaving arene rings for acyclic alkenylnitrile synthesis.

Synthetic chemistry is built around the formation of carbon-carbon bonds. However, the development ofmethods forselective carbon-carbon bond cleavage is a largely unmet challenge1-6. Such methods will have promising applications in synthesis, coal liquefaction, petroleum cracking, polymer degradation and biomass conversion. For example, aromatic rings are ubiquitous skeletal features in inert chemical feedstocks, but are inert to many reaction conditions owing to their aromaticity and low polarity. Over the past century, only a few methods under harsh conditions have achieved direct arene-ring modifications involving the cleavage of inert aromatic carbon-carbon bonds7,8, and arene-ring-cleavage reactions using stoichiometric transition-metal complexes or enzymes in bacteria are still limited9-11. Here we report a copper-catalysed selective arene-ring-opening reaction strategy. Our aerobic oxidative copper catalyst converts anilines, arylboronic acids, aryl azides, aryl halides, aryl triflates, aryl trimethylsiloxanes, aryl hydroxamic acids and aryl diazonium salts into alkenyl nitriles through selective carbon-carbon bond cleavage of arene rings. This chemistry was applied to the modification of polycyclic aromatics and the preparation of industrially important hexamethylenediamine and adipic acid derivatives. Several examples of the late-stage modification of complex molecules and fused ring compounds further support the potential broad utility of this methodology.

Ambient-Pressured Acid-Catalysed Ethylene Glycol Organosolv Process: Liquefaction Structure-Activity Relationships from Model Cellulose-Lignin Mixtures to Lignocellulosic Wood Biomass.

Raising the awareness of carbon dioxide emissions, climate global warming and fossil fuel depletion has renewed the transition towards a circular economy approach, starting by addressing active bio-economic precepts that all portion amounts of wood are valorised as products. This is accomplished by minimizing residues formed (preferably no waste materials), maximizing reaction productivity yields, and optimising catalysed chemical by-products. Within framework structure determination, the present work aims at drawing a parallel between the characterisation of cellulose–lignin mixture (derived system model) liquefaction and real conversion process in the acidified ethylene glycol at moderate process conditions, i.e., 150 °C, ambient atmospheric pressure and potential bio-based solvent, for 4 h. Extended-processing liquid phase is characterized considering catalyst-transformed reactant species being produced, mainly recovered lignin-based polymer, by quantitative 31P, 13C and 1H nuclear magnetic resonance (NMR) spectroscopy, as well as the size exclusion- (SEC) or high performance liquid chromatography (HPLC) separation for higher or lower molecular weight compound compositions, respectively. Such mechanistic pathway analytics help to understand the steps in mild organosolv biopolymer fractionation, which is one of the key industrial barriers preventing a more widespread manufacturing of the biomass-derived (hydroxyl, carbonyl or carboxyl) aromatic monomers or oligomers for polycarbonates, polyesters, polyamides, polyurethanes and (epoxy) resins.

Hydrothermal liquefaction conversion of lignocelluloses with enhanced fungal pretreatment

Although it is considered to be an environmental-friendly approach to reduce recalcitrance of lignocellulosic biomass, current fungal pretreatment methods suffer from major weaknesses, including inefficient delignification, loss of cellulose, and the need for long processing time. The addition of Mn to white-rot fungal treatment process could facilitate selective removal of lignin. However, the effect of Mn addition on the thermal decomposition and conversion of fungi-pretreated biomass is not clear. In this study, three types of lignocelluloses (poplar, wheat straw, and corn stover) were pretreated with fungi that was cultured with Mn supplements. Results demonstrated that the Mn addition affected thermogravimetric properties, as well as lignin and hemicellulose contents. The poplar samples showed the highest delignification (50.5 %) and lowest loss of cellulose (1.1 %). The initial degradation temperatures were lowered by 11–36 ℃, measured with thermogravimetric analysis. Additionally, fungi-pretreated feedstocks were converted in a two-stage hydrothermal liquefaction process to produce hydrolyzed sugars and value-added derivatives in a stepwise manner. A 163.6 % more hemicellulose sugars were recovered from poplar with the addition of Mn compared with untreated samples, while 75.2 % of hemicellulose sugar production was achieved in the first stage from fungi-treated corn stover with the Mn addition. Pretreating lignocelluloses with fungi that includes Mn supplements significantly improved sugar production. Thus, the combination of fungal pretreatment with the subsequent thermochemical conversion process offers a promising alternative technical route for lignocellulosic biomass valorization.

Economic impacts of feeding microalgae/wood blends to hydrothermal liquefaction and upgrading systems

Experimental work observed a synergetic effect of using microalgae/wood blended feedstocks for hydrothermal liquefaction (HTL) conversion with a yield advantage over using microalgae only or wood only as the feedstock. Experimental results for HTL and hydrotreating were used to develop the techno-economic analysis (TEA) for a blended feedstock HTL and biocrude upgrading system. For the blended feedstock system, wood is blended with algae feedstock during the lower algal productivity seasons (winter, fall, and spring) to match the maximum algal seasonal production rate. Adding woody biomass led to a 34% larger plant scale than the algae-only system with the same assumptions for algae seasonal productivity. In addition, low-cost woody biomass led to lower blended feedstock cost than the algae-only case. Blended feedstock also eliminated the need for drying a portion of the algae during summer and spring for winter and fall use, a requirement of the algae-only case, and thus reduced the related capital and operating costs. Economic analysis results indicated that, with feeding of microalgae/wood blended feedstock, the minimum fuel selling price (MFSP) to produce naphtha and diesel blendstock was reduced by 21% and the conversion-only cost (excluding cost for feedstock) was reduced by 13% compared to the algae-only case. Sensitivity analysis identified algae feedstock cost, algae blend ratios, and biocrude yields as key factors affecting the MFSP of the blended feedstock system.

Co-liquefaction of Xilinguole lignite and lignin in ethanol/water solvents under a cheap iron ore catalyst

The co-liquefactions of Xilinguole lignite (XL) and lignin in ethanol/water solvents were carried out at N2 atmosphere, and the effect of an in-situ H2-reduced hematite ore catalyst was also discussed in this study. Ethanol-water (50:50, v/v) mixed solvent gave a high liquefaction conversion of 45.7 wt%, but the oil yield was low as 14.9 wt% in the co-liquefaction of XL and lignin at 360 °C, 60 min and N2 atmosphere. Ethanol was a better solvent than ethanol-water (50:50, v/v) mixed solvent; it achieved both high of 44.3 wt% liquefaction conversion and 31.3 wt% oil yield in the same co-liquefaction condition. Formic acid could supply in-situ active H in the co-liquefaction of XL and lignin in ethanol/water solvents, and promoted the liquefaction conversion and oil yield. Addition of 10 v% formic acid in ethanol, the liquefaction conversion and oil yield further increased from 44.3 and 31.3 wt% (without formic acid) to 53.3 and 37.7 wt%, respectively in the co-liquefaction of XL and lignin at 360 °C, 60 min and N2 atmosphere. There existed a synergistic effect in the co-liquefaction of XL and lignin, and the synergistic effect was further promoted by the in-situ H2-reduced hematite ore catalyst. The oil yield increased from 34.5% without ore catalyst, to 48.7% under the ore catalyst, with the increments of 13.8% in the co-liquefaction of XL and lignin at 400 °C with ethanol as solvent and N2 atmosphere. The characterization of co-liquefaction products suggested that the in-situ H2-reduced hematite ore catalyst promoted more heavy constituents of XL converting into oil fraction, thus dramatically promoting the synergistic effect.