Search Results (14)

To develop efficient utilization technologies for lignite, HyperCoal was prepared from the depolymerization of Shengli lignite by reacting it with NaOH and methanol. A series of HyperCoal extracts were obtained using different solvents and characterized using elemental analysis, Fourier-transform infrared spectroscopy, gel permeation chromatography, and synchronous fluorescence spectroscopy. The results indicate that solvent polarity is the primary factor influencing both the extraction yield and the structure of the extracts as polar solvents can disrupt or break hydrogen bonds within the extracts. The extraction yield increases with the polarity of the extraction solvent. HyperCoal is a complex mixture of aromatic derivatives containing alkyl substituents and oxygen-containing functional groups. The O/C ratio and molecular size of the extracts, the amount of oxygen-containing functional groups, the proportion of aromatic structures, and the size of aromatic nuclei in the extracts increase with increasing solvent polarity, while the H/C ratio and proportion of aliphatic structures decrease. These findings aid developing methods for producing high-value-added chemicals from HyperCoal through staged conversion. Full article

Aromatics assume a paramount role as indispensable organic chemical feedstock within diverse industrial domains. Simultaneously, the global aromatics market is scarce, particularly with the exorbitant demand for high-value aromatics. Generating aromatics via coal-based methanol and low-carbon hydrocarbon coupling reactions has become a novel green and sustainable development trajectory. In this study, HZSM-5 catalysts featuring different Si/Al ratios and active metal-functionalized modifications were utilized to explore the aromatization effect in light of the Si/Al ratio, types of active components, and metal-loading content in a fixed-bed reactor. The outcomes were that the conversion ratios for methanol and n-pentane attained 99.9% and 83.1%, respectively. Remarkably, an oil phase yield of 32.1% was accomplished, along with an aromatic content of approximately 74.2%, while xylene selectivity reached approximately 37.6% for the 1.0%-ZnO/ZSM-5 (50) catalyst. Ultimately, a reaction mechanism for the coupling of methanol and n-pentane to yield aromatics using a 1.0%-ZnO/ZSM-5(50) catalyst is postulated. Full article

By allowing coal to be converted by microorganisms into products like methane, hydrogen, methanol, ethanol, and other products, current coal deposits can be used effectively, cleanly, and sustainably. The intricacies of in situ microbial coal degradation must be understood in order to develop innovative energy production strategies and economically viable industrial microbial mining. This review covers various forms of conversion (such as the use of MECoM, which converts coal into hydrogen), stresses, and in situ use. There is ongoing discussion regarding the effectiveness of field-scale pilot testing when translated to commercial production. Assessing the applicability and long-term viability of MECoM technology will require addressing these knowledge gaps. Developing suitable nutrition plans and utilizing lab-generated data in the field are examples of this. Also, we recommend directions for future study to maximize methane production from coal. Microbial coal conversion technology needs to be successful in order to be resolved and to be a viable, sustainable energy source. Full article

The process of coal-to-methanol conversion consumes a large amount of energy, and the use of the co-production method in conjunction with carbon capture, utilization, and storage (CCUS) technology can reduce its carbon footprint. However, little research has been devoted to comprehensively assessing the carbon footprint of the coal-to-methanol (CTM) co-production system coupled with CCUS-enhanced oil recovery technology (CCUS-EOR), and this hinders the scientific evaluation of its decarbonization-related performance. In this study, we used lifecycle assessment to introduce the coefficient of distribution of methanol and constructed a model to calculate the carbon footprint of the process of CTM co-production of liquefied natural gas (LNG) as well as CTM co-production coupled with CCUS-EOR. We used the proposed model to calculate the carbon footprint of the entire lifecycle of the process by using a case study. The results show that the carbon footprints of CTM co-production and CTM co-production coupled with CCUS-EOR are 2.63 t CO₂/tCH₃OH and 1.00 t CO₂/tCH₃OH, respectively, which is lower than that of the traditional CTM process, indicating their ability to achieve environmental sustainability. We also analyzed the composition of the carbon footprint of the coal-to-methanol process to identify the root causes of carbon emissions in it and pathways for reducing them. The work described here provided a reference for decision making and a basis for promoting the development of coal-to-methanol conversion and the CCUS industry in China. Full article

Reaching net-zero emissions by the middle of this century requires the implementation of massive carbon dioxide (CO₂) emission reduction strategies along with the reduction of other greenhouse gases on both global and country scales. Thus, carbon capture, storage, and utilization (CCSU) is a promising technology in combination with renewable energy transition. Currently, CO₂ utilization has attracted much attention from the scientific community worldwide, since it can improve the economic viability of CCSU deployment by creating a market for the recovered CO₂ stream. In this study, a brief assessment and comparison of potential CO₂ utilization pathways in Uzbekistan, including CO₂-to-chemical/fuel conversion, CO₂ bio-fixation/mineralization, and the direct use of CO₂, such as for enhanced hydrocarbon recovery (EHR), are conducted considering the CO₂ stationary sources and site-specific conditions of the country. In addition, possible challenges and opportunities for large-scale CO₂ utilization routes are also discussed. According to this assessment, there is great potential for the direct use of CO₂ as a process-boosting agent for EHR in more than 22 major natural gas, crude oil, and coal reservoirs. Moreover, methanol and urea production processes can also create huge market demand for recovered CO₂ as long as the conventional CO₂ production processes are replaced by sustainable ones. Full article

Methanol, which produced in large quantities from low-quality coal and the hydrogenation of CO₂, is a potentially renewable one-carbon (C1) feedstock for biomanufacturing. The methylotrophic yeast Pichia pastoris is an ideal host for methanol biotransformation given its natural capacity as a methanol assimilation system. However, the utilization efficiency of methanol for biochemical production is limited by the toxicity of formaldehyde. Therefore, reducing the toxicity of formaldehyde to cells remains a challenge to the engineering design of a methanol metabolism. Based on genome-scale metabolic models (GSMM) calculations, we speculated that reducing alcohol oxidase (AOX) activity would re-construct the carbon metabolic flow and promote balance between the assimilation and dissimilation of formaldehyde metabolism processes, thereby increasing the biomass formation of P. pastoris. According to experimental verification, we proved that the accumulation of intracellular formaldehyde can be decreased by reducing AOX activity. The reduced formaldehyde formation upregulated methanol dissimilation and assimilation and the central carbon metabolism, which provided more energy for the cells to grow, ultimately leading to an increased conversion of methanol to biomass, as evidenced by phenotypic and transcriptome analysis. Significantly, the methanol conversion rate of AOX-attenuated strain PC110-AOX1-464 reached 0.364 g DCW/g, representing a 14% increase compared to the control strain PC110. In addition, we also proved that adding a co-substrate of sodium citrate could further improve the conversion of methanol to biomass in the AOX-attenuated strain. It was found that the methanol conversion rate of the PC110-AOX1-464 strain with the addition of 6 g/L sodium citrate reached 0.442 g DCW/g, representing 20% and 39% increases compared to AOX-attenuated strain PC110-AOX1-464 and control strain PC110 without sodium citrate addition, respectively. The study described here provides insight into the molecular mechanism of efficient methanol utilization by regulating AOX. Reducing AOX activity and adding sodium citrate as a co-substrate are potential engineering strategies to regulate the production of chemicals from methanol in P. pastoris. Full article

The conversion of diverse non-petroleum carbon elements, such as coal, biomass, natural/shale gas, and even CO₂, into cleaner hydrocarbon fuels and useful chemicals relies heavily on syngas, which is a combination of CO and H₂. Syngas conversions, which have been around for almost a century, will probably become even more important in the production of energy and chemicals due to the rising need for liquid fuels and chemical components derived from sources of carbon other than crude oil. Although a number of syngas-based technologies, including the production of methanol, Fischer–Tropsch (FT) synthesis, and carbonylation, have been industrialized, there is still a great need for new catalysts with enhanced activity and adjustable product selectivity. New novel materials or different combinations of materials have been investigated to utilize the synergistic effect of these materials in an effective way. Magnetic materials are among the materials with magnetic properties, which provide them with extra physical characteristics compared to other carbon-based or conventional materials. Moreover, the separation of magnetic materials after the completion of a specific application could be easily performed with a magnetic separation process. In this review, we discuss the synthesis processes of various magnetic nanomaterials and their composites, which could be utilized as catalysts for syngas production and conversion. It is reported that applying an external magnetic field could influence the outcomes of any applications of magnetic nanomaterials. Here, the possible influence of the magnetic characteristics of magnetic nanomaterials with an external magnetic field is also discussed. Full article

A novel process path is proposed to produce glycolic acid (GA) from CO₂ as the feedstock, including CO₂ capture, power-to-hydrogen, CO₂ hydrogenation to methanol, methanol oxidation to formaldehyde, and formaldehyde carbonylation units. The bottlenecks are discussed from the perspectives of carbon utilization, CO₂ emissions, total site energy integration, and techno-economic analysis. The carbon utilization ratio of the process is 82.5%, and the CO₂ capture unit has the largest percentage of discharge in carbon utilization. Among the indirect emissions of each unit, the CO₂ hydrogenation to methanol has the largest proportion of indirect carbon emissions, followed by the formaldehyde carbonylation to glycolic acid and the CO₂ capture. After total site energy integration, the utility consumption is 1102.89 MW for cold utility, 409.67 MW for heat utility, and 45.98 MW for power. The CO₂ hydrogenation to methanol makes the largest contribution to utility consumption due to the multi-stage compression of raw hydrogen and the distillation of crude methanol. The unit production cost is 834.75 $/t-GA; CO₂ hydrogenation to methanol accounts for the largest proportion, at 70.8% of the total production cost. The total production cost of the unit depends on the price of hydrogen due to the currently high renewable energy cost. This study focuses on the capture and conversion of CO₂ emitted from coal-fired power plants, which provides a path to a feasible low-carbon and clean use of CO₂ resources. Full article

Thermochemical conversion of biomass waste is a high potential option for increasing usage of renewable energy sources and transferring wastes into the circular economy. This work focuses on the evaluation of the energetic and adsorption properties of solid residue (char) of the gasification process. Gasification experiments of biomass wastes (wheat straw, hay and pine sawdust) were carried out in a vertical fixed bed reactor, under a CO₂ atmosphere and at various temperatures (800, 900 and 1000 °C). The analysis of the energy properties of the obtained chars included elemental and thermogravimetric (TGA) analysis. TGA results indicated that the chars have properties similar to those of coal; subjected data were used to calculate key combustion parameters. As part of the analysis of adsorption properties, BET, SEM, FTIR and dynamic methanol vapor sorption tests were conducted. The specific surface area has risen from 0.42–1.91 m²/g (biomass) to 419–891 m²/g (char). FTIR spectroscopy confirmed the influence of gasification on the decomposition of characteristic chemical compounds for biomass. Methanol sorption has revealed for the 900 °C chars of pine sawdust the highest sorption capacity and its mass change was 24.15% at P/P₀ = 90%. Selected chars might be an appropriate material for volatile organic compounds sorption. Full article

This investigation scrutinizes the economic features and potential of propylene and methanol production from natural gas in Iran because greenhouse gas emissions released by natural gas-based production processes are lower than coal-based ones. Considering the advantage of Iran’s access to natural gas, this study evaluates and compares the economic value of different plans to complete the value chain of propylene production from natural gas and methanol in the form of four units based on three price scenarios, namely, optimistic, realistic, and pessimistic, using the COMFAR III software. Iran has been ranked as the second most prosperous country globally based on its natural gas reserves. Methanol and propylene production processes via natural gas will lower the release of greenhouse gas. This, increasing the investment and accelerating the development of methanol and propylene production units driven by natural gas will lead the world to a low emission future compared to coal-based plants. The economic evaluation and sensitivity analysis results revealed that the conversion of methanol to propylene is more attractive for investment than the sale of crude methanol. The development of methanol to propylene units is more economical than constructing a new gas to propylene unit because of the lower investment costs. Full article

With the increase in global energy requirements, the utilization of fossil fuels has also increased, which has caused global warming. In this study, a process integration framework based on an energy mix system is proposed to simultaneously produce two cleaner fuels (methanol and H₂). Aspen Plus is used to develop process models followed by their techno-economic assessment. Case 1 is considered the base case process, where the coal–biomass gasification process is used to produce the synthesis gas, which is further converted into H₂ and methanol. Conversely, the case 2 design represents the novel process configuration framework, where the coal–biomass gasification technology in case 1 is sequentially integrated with the methane reforming technology to minimize the energy penalties while increasing the net fuel production. To perform the technical analysis, the fuel production rates, carbon conversion efficiencies and specific energy requirements are compared for both models. It is analyzed from the results that the case 2 design offers higher methanol and H₂ production rates with lower energy requirements. Additionally, the specific energy requirement for case 2 is 29% lower compared to the case 1 design, leading to an increase in the process efficiency of case 2 by 3.5%. Full article

Characteristics of ZSM-5 synthesized from H₂SO₄-treated coal fly ash and fused coal fly ash extracts are compared in this study. In the synthesis process, fused coal fly ash extract (without an additional silica source) was used in the synthesis of ZSM-5. The effect of the structure-directing agent (tetrapropylammonium bromide, 1,6-hexanediamine or 1-propylamine) on the properties and methanol-to-olefins (MTO) effectiveness of the fly ash-based ZSM-5 was also investigated. A pure ZSM-5 synthesized from the fused coal fly ash extract led to a methanol conversion higher than 90% after 5 h on stream. The template 1,6-hexanediamine led to the synthesis of the most stable fly ash-based catalyst keeping a 44% methanol conversion after 24 h on stream. Full article

Carbon capture and utilization as a raw material for methanol production are options for addressing energy problems and global warming. However, the commercial methanol synthesis catalyst offers a poor efficiency in CO₂ feedstock because of a low conversion of CO₂ and its deactivation resulting from high water production during the process. To overcome these barriers, an efficient process consisting of three stage heat exchanger reactors was proposed for CO₂ hydrogenation. The catalyst volume in the conventional methanol reactor (CR) is divided into three sections to load reactors. The product stream of each reactor is conveyed to a flash drum to remove methanol and water from the unreacted gases (H₂, CO and CO₂). Then, the gaseous stream enters the top of the next reactor as the inlet feed. This novel configuration increases CO₂ conversion almost twice compared to one stage reactor. Also to reduce water production, a water permselective membrane was assisted in each reactor to remove water from the reaction side. The proposed process was compared with one stage reactor and CR from coal and natural gas. Methanol is produced 288, 305, 586 and 569 ton/day in CR, one-stage, three-stage and three-stage membrane reactors (MR), respectively. Although methanol production rate in three-stage MR is a bit lower than three stage reactors, the produced water, as the cause of catalyst poisoning, is notably reduced in this configuration. Results show that the proposed process is a strongly feasible way to produce methanol that can competitive with a traditional synthesis process. Full article

This paper proposes a polygeneration system based on a multi-input chemical looping combustion system, which generates methanol and electricity, through the use of natural gas and coal. In this system, the chemical looping hydrogen (CLH) production system and the coal-based methanol production system are integrated. A high quality fuel, natural gas, is used to improve the conversion ratio of coal. The Gibbs energy of the two kinds of fuels is fully used. Benefitting from the chemical looping process, 27% CO₂ can be captured without energy penalty. With the same outputs of methanol and electricity, the energy savings ratio of the new system is about 12%. Based on the exergy analyses, it is disclosed that the integration of synthetic utilization of natural gas and coal plays a significant role in reducing the exergy destruction of the new system. The promising results obtained in this paper may lead to a clean coal technology that will utilize natural gas and coal more efficiently and economically. Full article