Biogas Research Articles

Integration of in-situ and ex-situ power-to-gas (PtG) strategy for simultaneous bio-natural gas production and CO2 emission reduction

A novel system integrating an in-situ and ex-situ power-to-gas (PtG) system was developed in the current study. A continuous stirred-tank reactor (CSTR) was operated using cattle manure as substrate at mesophilic temperature (37 °C ± 2 °C). The CH4 content in the biogas was upgraded to above 95% by H2 injection, which meets the highest criteria for grid injection without requiring CO2 removal. Furthermore, the bio-nature gas production was promoted by external CO2 and H2 injection. The volumetric methane production rate (VMPR) was significantly increased by 739% from 117.4 mL L−1·d−1 to 985 mL⋅L−1⋅d−1, which is higher than in other studies. Meanwhile, the volumetric biogas production rate (VBPR) was increased by 36.9% by H2 injection, increasing the conversion efficiency (82.56%) of the chemical oxygen demand (COD) to CH4. A significant increase in the specific methanogenic activity of dissolved hydrogen (SMA(Hdissolved)) and the enrichment in hydrogenotrophic methanogens (Methanobacterium) demonstrate that the CH4 production pathway was converted from acetoclastic methanogenesis (AM) pathway to hydrogenotrophic methanogenesis (HM) pathway. It is postulated that the change in proportion of different pathways of the CH4 production was caused by the strengthening of key enzymes (coenzyme F420 hydrogenase and coenzyme-B sulfoethylthiotransferase) by H2 injection. The integrated system represents a promising approach to achieve simultaneous CO2 emission reduction and bio-natural gas production.

(Invited) Utilization of Bio-CO2 and Bio-Methane for Fuel Production: Integration Solid Oxide Electrolyzer, Low Energy Plasma Reformer with Fischer-Tropsch Synthesis

Transition to renewable energy is essential to achieve climate protection objectives. Besides storing electricity for later use, fuel production using renewable energy is an essential part of reducing fossil dependance. The highest value application in current markets is the production of liquid transportation fuels such as sustainable aviation fuels (SAF) from sustainable, ideally biogenic carbon resources. A system is presented for processing anaerobic digester gas for liquid hydrocarbon production. Bio-CO2 is processed through a solid oxide electrolysis cell and bio-CH4through a low energy plasma reformer. The combined synthesis gas is supplied to a Fischer-Tropsch reactor for the production of liquid hydrocarbons. The combination of technologies nearly doubles the yield of biofuel by utilizing the bio-CO2 in addition to the bio-CH4. The product fuel is all bio-carbon but it also embodies renewable electric energy in a high-value, storable and transportable liquid hydrocarbon.

Marine Microalgae as a Nutritive Tool to Mitigate Ruminal Greenhouse Gas Production: In Vitro Fermentation Characteristics of Fresh and Ensiled Maize (Zea mays L.) Forage.

The aim of the present study was to evaluate the effects of marine microalgae (Dunaliella salina) as a food additive on biogas (BG), methane (CH4), carbon monoxide (CO), and hydrogen sulfide (H2S) production kinetics, as well as in in vitro rumen fermentation and the CH4 conversion efficiency of different genotypes of maize (Zea mays L.) and states of forage. The treatments were characterized by the forage of five maize genotypes (Amarillo, Montesa, Olotillo, Tampiqueño, and Tuxpeño), two states of forage (fresh and ensiled), and the addition of 3% (on DM basis) of microalgae (with and without). The parameters (b = asymptotic production, c = production rate, and Lag = delay phase before gas production) of the production of BG, CH4, CO, and H2S showed an effect (p < 0.05) of the genotype, the state of the forage, the addition of the microalgae, or some of its interactions, except for the time in the CO delay phase (p > 0.05). Moreover, the addition of microalgae decreased (p < 0.05) the production of BG, CH4, and H2S in most of the genotypes and stages of the forage, but the production of CO increased (p < 0.05). In the case of fermentation characteristics, the microalgae increased (p < 0.05) the pH, DMD, SCFA, and ME in most genotypes and forage states. With the addition of the microalgae, the fresh forage from Olotillo obtained the highest pH (p < 0.05), and the ensiled from Amarillo, the highest (p < 0.05) DMD, SCFA, and ME. However, the ensiled forage produced more (p < 0.05) CH4 per unit of SFCA, ME, and OM, and the microalgae increased it (p < 0.05) even more, and the fresh forage from Amarillo presented the highest (p < 0.05) quantity of CH4 per unit of product. In conclusion, the D. salina microalga showed a potential to reduce the production of BG, CH4, and H2S in maize forage, but its effect depended on the chemical composition of the genotype and the state of the forage. Despite the above, the energy value of the forage (fresh and ensiled) improved, the DMD increased, and in some cases, SCFA and ME also increased, all without compromising CH4 conversion efficiency.

Scale Up and Coupling of the MOXIE Solid Oxide Electrolyzer for Both Terrestrial and Space Applications

The Mars Oxygen ISRU Experiment (MOXIE) is a first of its kind demonstration of in-situ resource utilization technology to produce propellant and breathable oxygen from the Mars ambient carbon dioxide. The use of Lunar and Martian resources represents a significant opportunity to reduce the cost of launch from Earth, enabling propellant production for space refueling, and allowing for life support of manned missions to the Lunar and Martian surfaces.Since developing the Solid OXide Electrolysis (SOXE) stacks for the Mars 2020 MOXIE program in 2017, the OxEon team has made significant advancements in scale and capabilities of the SOXE stack technology used in that system. Newer variants have a five-fold larger cell area and a 6.5-fold increase in cells per stack, for a stack scaled 33-times the 0.5% scale of the device in MOXIE. Six of these OxEon mission-scale SOXE stacks will produce 30 tons of propellant oxygen to fuel a Mars Ascent Vehicle (MAV) in the 19-month window between landing an unfueled MAV pre-supply mission and the next launch opportunity for the first crewed Mars Mission, meeting target requirements for a return mission. OxEon has built and demonstrated systems with mission-scale stacks for both Lunar and Martian applications. A system for the production of propellant H2 and O2 from Lunar ice was successfully tested in a cryo-vac chamber at the Colorado School of Mines in 2022. Another mission-scale demonstration system is scheduled to demonstrate production of O2 and methane from Martian H2O and atmospheric CO2 at Jet Propulsion Laboratory in 2022.In addition to SOXE/SOFC systems, the OxEon technology portfolio also consists of a low energy plasma reformer capable of producing sygnas from a variety of hydrocarbons and a modular-scale Fischer-Tropsch reactor for the production of liquid fuels from syngas. These technologies allow OxEon to provide a wide range of terrestrial energy solutions. A DOE Bioenergy Technologies Office (BETO) funded system is currently being fabricated to demonstrate the conversion of both CO2 and CH4 in anaerobic digester gas to liquid transportation fuels. This will be accomplished using an SOEC system to convert steam and CO2 to synthesis gas. OxEon’s plasma reformer will be used to convert methane to synthesis gas, using the plasma to catalyze the reaction of methane with steam and oxygen, supplied in part by the byproduct oxygen from the electrolysis system. The syngas from the plasma reformer and electrolysis systems are then combined to produce liquid fuels in the Fischer-Tropsch (FT) reactor. Figure 1

Energy-efficient storage of methane and carbon dioxide capture in the form of clathrate hydrates using a novel non-foaming surfactant: An experimental and computational investigation

In recent decades, both rising energy demand and increasing population have led to a significant increase in atmospheric carbon dioxide (CO2). Natural gas, the primary source of energy, and carbon capture and storage must therefore be managed efficiently. Gas hydrates have considerable potential for CO2 capture and energy storage since they can selectively absorb gas molecules and provide a large storage capacity. However, the slow kinetics of the hydrate formation constrained their commercial usage. Although surfactants have been investigated as effective additives to accelerate the rate of gas hydrate formation, intense foaming during the gas hydrate dissociation adversely affects the gas recovery factor. In this study, a novel anionic surfactant based on aconitic acid (ASA) was developed to improve the kinetics of methane and CO2 hydrates formation. The methane hydrate experiments indicated that, even at low concentrations, ASA significantly enhanced the kinetics of methane hydrate formation. The maximum water-to-hydrate conversion of 97 % and the highest storage capacity of 174 v/v were achieved using 50 ppm of ASA. Additionally, 99.1 v/v of storage capacity was achieved for CO2 hydrate in the solution containing 1000 ppm of ASA. Moreover, molecular dynamics simulation revealed that self-assembly behavior of ASA molecules increased the solubility of the gas molecules in the solution, provided more gas molecules for growing hydrate interface, and increased gas hydrate growth. Furthermore, no foam formation occurred in the ASA solution, even at high concentrations. These results show that ASA can be applied as an efficient and foamless gas hydrate promoter for methane storage and CO2 capture applications.

Derivation of Optimal Operation Factors of Anaerobic Digesters through Artificial Neural Network Technology

The anaerobic digestion of sewage sludge in South Korean wastewater treatment plants is affected by seasonal factors and other influences, resulting in lower digestion efficiency and gas production, which cannot reach optimal yields. The aim of this study was to improve the digestion efficiency and gas production of sludge anaerobic digestion in a wastewater treatment plant (WWTP) by using data mining techniques to adjust operational parameters. Through experimental data obtained from the WWTP in Daegu City, South Korea, an artificial neural network (ANN) technology was used to adjust the range of the organic loading rate (OLR) and hydraulic retention rate (HRT) to improve the efficiency and methane gas production from anaerobic sludge digestion. Data sources were normalized, and data analysis including Pearson correlation analysis, multiple regression analysis and an artificial neural network for optimal results. The results of the study showed a predicted 0.5% increase in digestion efficiency and a 1.3% increase in gas production at organic loads of 1.26–1.46 kg/m3 day and an HRT of 26–30 days. This shows that the ANN model that we established is feasible and can be used to improve the efficiency and gas production of sludge anaerobic digestion.

Petroleum++: Should SPE Be Part of the Conference of the Parties (COP)28?

_ As most of our members know, the United Nations Framework Convention on Climate Change (UNFCCC) convenes annually at a meeting called Conference of the Parties (COP) in various host countries, usually in November or December. COP is the main decision-making body of the UNFCCC. It includes representatives from all the countries that are signatories (or Parties) to the UNFCCC. COPs are where Parties (governments) assess global efforts to advance the key Paris Agreement aim of limiting global warming to as close as possible to 1.5°C above pre-industrial levels. This year COP28 will be in Dubai. Although these meetings are focused on mitigating climate change concerns, there is usually considerable time spent on current and future sources of energy. It is noteworthy that our industry, the main provider of energy to the world right now and, as many members of SPE know, for the foreseeable future, is usually not represented in these conferences. This started to change last year in Sharm El Sheikh, and we will probably see more involvement in Dubai. I think SPE, as the largest professional society for the production of the dominant energy source, needs to be part of the discussion. Related to my 2023 theme, Petroleum ++, we have an important role to play in mitigating climate change concerns (the first +) and in developing new low- or no-carbon sources of energy (the second +). We are a technical society that does not lobby or advocate. We offer a forum for presenting and disseminating scientifically vetted technical information about what can be and is being done by our members in the expanded space of our work in the areas of climate change and new energy. We also need to emphasize the fact that we are citizens of this planet, and we care about its future for us and the next generations. I would like to share the points I am making with the organizers of COP28 about our efforts for two reasons. First, to share with our members the efforts being made in this regard and second, for our members to use this information in further developments in their work and discussions with others about the role of petroleum engineering in the expanded energy landscape. Reducing Emissions The SPE Methane Emissions Management Technical Section (MEMTS) was formed in June 2022 to provide a platform for learning and collaboration for SPE members working or interested in the topic. The purpose of MEMTS is to further the objectives of SPE in open discussion of methane emissions management, to generate awareness on industry best practices, and to promote those practices widely. MEMTS is intended to accelerate the translation of technologies and ways of working across upstream, midstream, and downstream to reduce the risk and costs of methane emissions management projects, including: - Planning, measuring, monitoring, recording, analysis, and reporting emissions. - Addressing key abatement activities: fugitive emissions, venting emissions, flaring, methane capture, and use. - Promoting best practices and standardization. - Sharing digitalization best practices. - Supporting related R&amp;D activities. - Addressing the regulatory landscape for emissions. - Optimizing costs and resources. - Addressing corporate risk, governance, and monetization (carbon credits, stock value).

Beneficial impacts of biochar as a potential feed additive in animal husbandry

In the last decade, biochar production and use have grown in popularity. Biochar is comparable to charcoal and activated charcoal because it is a pyrogenic carbonaceous matter made by pyrolyzing organic carbon-rich materials. There is a lack of research into the effects of adding biochar to animal feed. Based on the reviewed literature, including its impact on the adsorption of toxins, blood biochemistry, feed conversion rate, digestion, meat quality, and greenhouse gas emissions, adding biochar to the diet of farm animals is a good idea. This study compiles the most important research on biochar's potential as a supplement to the diets of ruminants (including cows and goats), swine, poultry, and aquatic organisms like fish. Biochar supplementation improves animal growth, haematological profiles, meat, milk and egg yield, resistance to illnesses (especially gut pathogenic bacteria), and reduced ruminant methane emission. Biochar's strong sorption capacity also helps efficiently remove contaminants and poisons from the animals' bodies and the farm surroundings where they are raised. Animal farmers are predicted to make greater use of biochar in the future. Biochar could potentially be of value in the healthcare and human health fields; hence research into this area is encouraged. The present review highlights the potential benefits of biochar as an additive to animal feed and demonstrates how, when combined with other environmentally friendly practices, biochar feeding can extend the longevity of animal husbandry.

Effect of PGPR and Biogas Slurry on Growth and Yield Parameters of Pea under Salt Affected Conditions

Salt stress is a significant abiotic plant growth restrictive factor; it is becoming a severe environmental threat. The microorganism in the rhizosphere especially fungi and bacteria can increase the plant production under stress conditions both by direct and indirect mechanisms. A field experiment was conducted to evaluate the potential of biogas slurry and plant growth promoting rhizobacteria (PGPR) at different levels of salinity to improve the growth and yield of pea (Pisum sativum ). In field experiment biogas slurry @ 600 kg ha-1 and 800 kg ha-1 and PGPR strain “bacillus subtilis” was applied along with 6 dS m-1 and 8 dS m-1 levels of salt stress in addition to recommended doses of nitrogen, potassium and phosphorus fertilizer. The results revealed that the combined application of PGPR and biogas slurry under normal soil conditions increased shoot length by 30.27% while under saline conditions it increased up-to 65.27%. Soil salinity reduced root length up-to 79.155% at 8 dS m-1 as compared to control. Application of biogas slurry improved 5.93% root length under salt stress as compared to respective control, on the other hand the combined application of PGPR and biogas slurry increased root length by 33.128% under normal conditions and under salinity stress it increased by 73.53%.Soil salinity reduced chlorophyll content 36.54% of pea decrease under salt stress, the application of biogas slurry under the same condition improved 29.26% chlorophyll content of pea but the combined application of PGPR and biogas slurry enhanced the chlorophyll contents 4.68% as compared to solely application of biogas slurry. The results clearly indicated that the combined application of PGPR and biogas slurry is the best source to enhance the growth and yield of pea under normal as well as under salinity stress.&#x0D; Key Words: PGPR, Bio gas, Salinity, Peas, Growth, Yield.

Applications of agricultural waste in food industry

Agricultural wastes are by-product outputs of production and processing of agricultural products that contain bioactive compounds, which have many benefits on human health. Agricultural wastes produced from various sources such as cultivation, livestock, industrial means, and etc are great concern because of the problems of environmental pollution, recycling and utilization. Therefore, application of agricultural wastes in any other environmentally friendly way like compost production by fermenting the agricultural, animal feed production, food production and energy production (bio gas) is suggested. It can be concluded that recycling agricultural wastes is important and necessary for environment and economical saving. This recycling of agriculture wastes enhance agricultural and food production along with improve their quality.

Study of On-Site Upgraded Livestock Biogas Production and Carbon Emission Reduction By Substituting Coals For Thermal Power Generation

The objective of this project is to integrate a farm-scale bio-desulfurization facility with a novel biogas hollow fibre adsorption module for biogas desulfurization and bio-natural gas production. In this study, the desulfurization experimental results showed that the bio-desulfurization system can remove 96.7 ± 6% of H2S from the biogas after an approximately two-month enrichment period. The average CH4, N2, and CO2 concentrations in raw biogas were 63.4, 15.2, and 21.1%, respectively. As for biogas upgrading experiments, the inlet biogas flow rates were applied from 5 to 20 L/min. The removal efficiency of CO2 under all biogas flow rates was 100%. Meanwhile, methane was promoted from 60% to nearly 94% (i.e. 57% increase in methane concentration). The replacement of anthracite and coking coal by upgraded biogas might reduce 44.4% and 42.5% of CO2 equivalent, respectively. The achievement of this project pursues the mitigation of carbon dioxide emissions by using upgraded pig biogas which can be enlarged and extended to all decentralized pig farms worldwide.

Study of on-site upgraded livestock biogas production and carbon emission reduction by substituting coals for thermal power generation

The objective of this project is to integrate a farm-scale bio-desulfurization facility with a novel biogas hollow fibre adsorption module for biogas desulfurization and bio-natural gas production. In this study, the desulfurization experimental results showed that the bio-desulfurization system can remove 96.7 ± 6% of H2S from the biogas after an approximately two-month enrichment period. The average CH4, N2, and CO2 concentrations in raw biogas were 63.4, 15.2, and 21.1%, respectively. As for biogas upgrading experiments, the inlet biogas flow rates were applied from 5 to 20 L/min. The removal efficiency of CO2 under all biogas flow rates was 100%. Meanwhile, methane was promoted from 60% to nearly 94% (i.e. 57% increase in methane concentration). The replacement of anthracite and coking coal by upgraded biogas might reduce 44.4% and 42.5% of CO2 equivalent, respectively. The achievement of this project pursues the mitigation of carbon dioxide emissions by using upgraded pig biogas which can be enlarged and extended to all decentralized pig farms worldwide.

Exploration on laminar flame propagation of biogas and DME mixtures up to 10 atm: Insight into effects of DME co-firing, CO2 addition and pressure

Biogas (BG) is an important renewable fuel from biomass feedstock with methane and carbon dioxide (CO2) as the main components. Its low fuel reactivity and flame stability caused by the considerable CO2 content raises the research need for the enhancement of its combustion. In this work, the laminar flame propagation of BG and DME mixtures was investigated with special attentions on the effects of DME co-firing, CO2 addition and pressure. The laminar burning velocities of BG/DME/air mixtures were measured at 298 K, varying initial pressures (1–10 atm), DME contents in fuel mixtures (0–1), CO2 contents in BG (0–0.4), and equivalence ratios (0.7–1.4). It was concluded that the laminar burning velocity can be effectively improved with the increasing DME content, moderately reduced with the increasing CO2 content, and dramatically reduced at elevated pressures. Meanwhile, a kinetic model of BG/DME combustion was developed and validated against the experimental data in both this work and literature. The modeling analysis shows that the enhanced flame propagation with DME co-firing is associated with the increased concentrations of key radicals like H, O, and OH due to the increased adiabatic flame temperatures and the enhanced DME-related pathways. On the other hand, the inhibited flame propagation with CO2 addition is associated with the decreased concentrations of key radicals. The fictitious diluent gas method was used to separate the different effects of DME co-firing and CO2 addition. The thermal effects play a more important role than the chemical effects in the increased laminar burning velocity with the DME co-firing, while the contributions to the decreased laminar burning velocities with the CO2 addition obey the order of thermal effects > chemical effects > dilution effects. Moreover, the pressure effects in the laminar flame propagation of BG/DME mixtures reduce with the increasing DME content, but remain nearly unchanged with the increasing CO2 content. This is mainly because the DME co-firing can reduce the significance of the most important chain-termination pathway, i.e., CH4 (+M) = CH3 + H (+M), while the CO2 addition does not have adequate influence.

Anaerobic Digestion (AD) Based Waste Management in Nepal: Technologies and Implementation Modalities

Developing countries are still facing severe challenges for providing access to clean energy, managing waste and struggling to meet Sustainable Development Goals (SDG) targets. Anaerobic Digestion (AD) based waste management technologies have great potential for addressing these challenges. Public Private Partnerships (PPP) are the key government's policy and strategic directions for promoting biogas as a multi-beneficiary's product and services in Nepal. Nepal's biogas promotion PPP model and technologies in domestic biogas sector have been replicated in many African and Asian countries. AD based Gobar Gas Company (GGC 2047 model) and Continuously Stirred Tank Reactor (CSTR) based technologies have been promoted for domestic and large applications respectively in wider scale. Comprehensive review and analysis using technological and implementation progress results through government interventions revealed that with the potential of 1.1 million of domestic biogas 433,173 systems have been installed. Quantification of outcomes of AD based technologies revealed that in addition to the energy access to more than 1.8 million people, these significantly contributed for production of gas amounting 456,282 m3 and substituted equivalent 15,578 nos. of LPG cylinders and 2229.91 tons of fertilizer daily. Under Carbon Development Mechanism (CDM), Total 21.20 million USD have been earned as carbon revenue from this sector, which has played significant role for earning revenue from carbon financing. Similarly, Developing Carbon Program for Large Scale Biogas through ITMO (Internationally Transferred Mitigation Outcomes: a new carbon mechanism) is under way. Overall, biogas sector is contributing for country' s energy security and circular economy through replacement of fossil fuels and chemical fertilizers along with the waste management.

A HYBRID MPPT ALGORITHM FOR SOLAR PV WITH BATTERY CONNECTED SYSTEM

Electricity generation using renewable energy resources rather than fossil fuels reduces gobar gas emissions from the power sector and prevents pollution. The best alternative to conventional energy sources is solar photovoltaic (PV) generation; however, it has some significant disadvantages, including high initial costs, poor photoconversion efficiency, and climatic dependencies. In order to overcome this, PPT techniques are used. The projected work provides a solar power system which tracks the maximum power point using Artificial Neural Network and Perturb and Observe algorithm. Additionally, it adds a new setup for the system that links the photovoltaic array as well as the battery to the system inverter’s DC-link through a single DC-DC converter that can act as both charge controller and Maximum Power Point Tracking (MPPT) device at the same time. When solar energy production exceeds demand, the excess energy is stored in batteries and provided during periods of very low irradiance. The DC voltage is converted into AC voltage using an inverter. The benefit of this technique is that it has greater tracking accuracy. For validation, the proposed model has been analyzed by using MATLAB/Simulink.

Lactic acid bacteria and yeast strains isolated from fermented fish (Budu) identified as candidate ruminant probiotics based on in vitro rumen fermentation characteristics.

Probiotic supplementation can assist with manipulating the rumen microbial ecosystem. Lactic acid bacteria and yeast from fermented fish (Budu) as the indigenous food from West Sumatra, Indonesia, are potential probiotics for livestock. This study aims to select the best candidate lactic acid bacteria and yeast strains from fermented fish as ruminant probiotics and evaluate the effect of their supplementation on the characteristics of rumen fermentation, feed digestion, and total gas production in vitro. This study used nine treatments, performed in triplicate, in a completely randomized design. The substrate ratio comprised of 70% Pennisetum purpureum forage and 30% concentrate. Five lactic acid bacteria and three yeast isolates were used in this study. Treatments were as follows: T0: control (basal diet); T1: T0 + Lactobacillus parabuchneri strain 3347; T2: T0 + Lactobacillus buchneri strain 5296; T3: T0 + Lactobacillus harbinensis JCM 16178; T4: T0 + Schleiferilactobacillus harbinensis strain LH991; T5: T0 + L. parabuchneri strain 6902; T6: T0 + Pichia kudriavzevii strain B-5P; T7: T0 + P. kudriavzevii strain CBS 5147; and T8: T0 + commercial yeast (Saccharomyces cerevisiae). The lactic acid bacteria inoculum contained 1.02 × 1011 colony-forming unit (CFU)/mL, while the yeast inoculum contained 1.5 × 1010 CFU/mL. The results showed that four lactic acid bacteria and three yeast produced a higher total gas yield (104-183.33 mL) compared to the control (103 mL). Supplementation with lactic acid bacteria in the rumen fermentation in vitro showed dry matter digestibility of 63%-70% and organic matter digestibility (OMD) of 64%-71%. We observed that total volatile fatty acid (VFA) production in all treatments was significantly higher (86-121 mM) compared to the control (81 mM). The concentration of NH3 production was higher in all treatments (12.33-16.83 mM) than in the control (12.25 mM). Meanwhile, the probiotic supplementation did not cause a significant change in the rumen pH (6.86-7.12). Supplementation with the lactic acid bacteria S. harbinensis strain LH991 consistently demonstrated the best results from the parameters of dry and OMD (70.29% and 71.16%, respectively), total VFA (121.67 mM), NH3 (16.83 mM), and total gas production (149.17 mL). The best results were observed from the yeast candidate P. kudriavzevii strain B-5P, where the results were dry and OMD (67.64% and 69.55% respectively), total VFA (96.67 mM), NH3 (13.42 mM), and total gas production (183.33 mL). Based on the obtained results, lactic acid bacteria S. harbinensis strain LH991 and yeast P. kudriavzevii strain B-5P are attractive candidates to be utilized as probiotics for ruminants based on their potential to improve rumen fermentation in vitro. This probiotic supplementation can increase the digestibility of feed ingredients, production of total VFA and NH3, and total gas produced.

Highly scalable acid-base resistant Cu-Prussian blue metal-organic framework for C2H2/C2H4, biogas, and flue gas separations

One of the emerging problems plaguing the chemical industry today is the selective capture and separation of gases from their mixtures in an efficient and cost-effective manner. MOFs are new-age physisorbent materials extensively investigated for various gas mixture separations (such as biogas, flue gas, olefin/paraffin etc.); however, face the challenge of separations in a realistic environment. Here, we have investigated one of the Prussian blue analogues (Cu-PSB) to explore its potential as energy-efficient gas separation material. Cu-PSB can easily be scaled up at room temperature from water and is highly robust under harsh acidic, basic environments (pH = 1–11, 6 M HCl, 18 M H2SO4), exhibiting excellent separation of C2H2/C2H4, biogas (CO2:CH4 = 50:50), and flue gas (CO2:N2 = 15:85) mixtures. The IAST selectivity at ambient conditions (295 K, 50:50 mixture) could reach up to 5.2 for C2H2/C2H4, 14.7 for CO2/CH4, and 60.5 for the CO2/N2 (15:85 mixture). Such high C2H2 and CO2 uptake capacity and separation selectivity could be attributed to the synergistic effect of open CuII sites and the multiple H-bonding interactions within the functional pore channels of optimal pore size. Further, breakthrough simulation confirmed the complete separations from their binary mixtures, thus proving to be highly useful for the C2H2/C2H4 separation and CO2 capture from the bio and post-combustion flue gas mixtures. Cu-PSB was found to be even a more robust framework than ZIF-8 and UiO-66 MOFs.

Regenerative Food Forest: A Case Study of Vanya Organic Farm

Food Forests involve planned agro-forestry. A food forest like a real forest needs no pesticides, herbicides, weeding, crop rotation, mowing or digging. It will ensure the sustainability of flora and fauna, birds, animals and most importantly bees. This is a case study of one such food forest, Vanya Organic which is a dream turned into reality by one of its owners, Mr. Patanjali Jha. He grew native trees, creepers and shrubs in combination with symbiotic vegetation to ensure maximum carbon sequestration, provide forest cover and usable by-products A very important part of his food forest is the inclusion of Vetiver Grass. Mr. Jha suggests that Food Forests and Vetiver Plantations should be looked at together and set up together and called a Regenerative Food Forest. Compressed Bio Gas (CBG) or Renewable Natural Gas (RNG), a Green Fuel, is derived from agriculture waste or other forms of organic waste called biomass which is produced in abundance by the regenerative food forests. A CBG plant produces Sulphur stripped Methane of automotive grade and also produces a very high-quality organic fertilizer as a by-product which has been approved for regular use by the Ministry of Agriculture. Therefore, there is a need to link these CBG Plants with regenerative food forests. It will provide jobs, increase farm incomes, and over a period of time, this will induce positive sustainable changes in air, water and soil quality. The case study has been prepared with his consent and approval.

Methane capture with α-cyclodextrins

α-cyclodextrin forms a crystalline 1 : 1 complex with methane that release the gas upon addition of water.

In silico capture and activation of methane with light atom molecules.

Methane (CH4) can be captured in silico with a light atom molecule containing only C, H, Si, O, and B atoms, respectively. A tripodal peri-substituted ligand system was employed, namely, [(5-Ph2B-xan-4-)3Si]H (1, xan = xanthene), which after hydride abstraction (1+) carries four Lewis acidic sites within the cationic cage structure. In a previous study, this system was shown to be able to capture noble gas atoms He-Kr (Mebs & Beckmann 2022). In the corresponding methane complex, 1+CH4, a polarized Si+⋯CH4 contact of 2.289 Å as well as series of (H3)CH⋯O/CPh hydrogen bonds enforce spatial CH4 fixation (the molecule obeys C3-symmetry) and slight activation. A trigonal-pyramidal Si-CHeq3-Hax local geometry is thereby approached with Hax-C-Heq angles decreased to 103.7°. All attempts to replace the Lews acidic -BPh2 fragments in 1 with basic -PR2 (R = Ph, tBu) fragments indeed increased intra-molecular hydrogen bonding between host molecule and CH4, and thus caused stronger activation of the latter, however ultimately resulted in the formation of energetically favorable quenched structures with short P-Si contacts, making CH4 binding hard to achieve. The electronic situation of two hypothetic methane complexes, 1+CH4 and [(5-tBu2P-xan-4-)3SiCH4]+ (2+CH4), was determined by a set of calculated real-space bonding indicators (RSBIs) including the Atoms-In-Molecules (AIM), non-covalent interactions index (NCI), and electron localizability indicator (ELI-D) methods, highlighting crucial differences in the level of activation. The proposed ligand systems serve as blueprints for a more general structural design with adjustable trigonal ligand systems in which central atom, spacer fragment, and functional peri-partner can be varied to facilitate different chemical tasks.