Peatlands can become valuable resources and greenhouse gas sinks through the use of different management practices. Peatlands provide carbon sequestration; however, they are also among the greatest greenhouse gas emissions sources. The estimated annual carbon dioxide equivalent emissions from peat worldwide are 220 million tons. Novel strategies, methods, and technologies must be developed to enhance the sustainable use of peatlands and achieve climate targets by 2050, as set forth by the European Commission. There is no consensus in the scientific literature on which strategies included in the policy documents are more fruitful for reducing emissions. There are uncertainties and knowledge gaps in the literature that summarise the cons and benefits of each strategy regarding the potential of GHG emission reduction. Currently, peat is undervalued as a resource in the bioeconomy and innovation—a way that could save costs in peatland management. This review paper aims to analyse existing and potential strategies to minimise greenhouse gas emissions from peatlands. Studies show significant debates in the literature on whether the rewetting of peatlands and afforestation of previously drained peatlands can be defined as restoration. A more effective management of peatland restoration should involve combining restoration methods. The rewetting of peatlands should be realised in combination with top-soil removal to minimise methane emissions. The rewetting of peatlands should be used only in combination with revegetation after rewetting. One of the promising solutions for methane emission reduction could be paludiculture using sphagnum species. Products from paludiculture biomass can reduce GHG emissions and store long-term emissions in products. Paludiculture can also be the solution for further income for landowners and innovative products using the biomass of harvested paludiculture plants.

Energy plans of many countries anticipate an increased use of biomethane for energy supply, i.e., in power and heat production as well as in the transport sector. Existing infrastructure of natural gas storage, supply and application provides a good platform to facilitate transfer to biomethane utilization on a larger scale. One key element of the biomethane system is the upgrade of the biomass-derived synthesis gas originating from different sources, to a quality of natural gas (SNG - Synthesis Natural Gas) via the methanation process for further injection into the natural gas grid.. The maximisation of efficiency of the methanation process is of critical importance in order to make biomethane technology viable for wider application. The aim of the study was to improve efficiency of the methanation process by finding the optimum temperatures and pressure. Theoretical modelling of adiabatic and isothermal methanation processes by using thermodynamic equilibrium calculations was introduced as a method for the study. The results show the impact of temperature and pressure changes on the overall efficiency of methane production. It can be concluded from the study that knowledge about the relation between temperature, pressure and the efficiency of the methanation process makes it possible to optimize the process under various biomass synthesized gas input conditions.

Latvia aims for 40% share of renewable energy in the total final energy use. Latvia has large resources of biomass and developed district heating systems. Therefore, use of biomass for heat and power production is an economically attractive path for increase of the share of renewable energy. The optimum technological solution for use of biomass and required fuel resources have to be identified for energy planning and policy purposes. The aim of this study was to compare several wood fuel based energy conversion technologies from the technical and economical point of view. Three biomass conversion technologies for combined heat and electricity production (CHP) were analyzed: • CHP with steam turbine technology; • gasification CHP using gas engine; • bio-methane combined cycle CHP. Electricity prices for each alternative are presented. The results show the level of support needed for the analyzed renewable energy technologies and time period needed to reach price parity with the natural gas - fired combined cycle gas turbine (CCGT) CHPss. The results also show that bio-methane technology is most competitive when compared with CCGT among the considered technologies regarding fuel consumption and electricity production, but it is necessary to reduce investment costs to reach the electricity price parity with the natural gas CCGT.

Epoxy resins are widely used polymers that are mainly synthesized from fossil feedstocks. In order to reduce the use of fossil-derived epoxies, various solutions are widely studied, such as replacing conventional raw materials with more environmentally friendly, non-toxic solutions, such as vegetable oil. One of the less studied but potentially highly competitive feedstock for the synthesis of bio-based epoxies is single-cell oils (SCO). Single-cell oils have a number of advantages over vegetable oils, such as the fatty acid profiles of SCO are more suitable for the polymerization of epoxides, the production of SCOs is faster and more environmentally friendly. Thanks to the wide range of SCO-producing microorganisms, it is possible to find the exact SCO that is suitable for the specific application of the produced epoxy. Despite the potential advantages, SCO derived from microorganisms such as yeasts, fungi and bacteria, have received very limited coverage in the scientific literature. Therefore, this review summarizes the available information on single-cell oils and evaluates their suitability for use as feedstock in epoxide synthesis. The following aspects are reviewed in this paper: microorganism strains that can be used in the production of SCO; fermentation rates and SCO yields; applicable low-cost raw materials used for the cultivation of microorganisms; the fatty acid profile of the relevant SCO and other factors that are significant for suitability evaluation of the relevant SCO. To the best of authors knowledge this is the first review paper to summarize potential SCOs for their application in synthesis of bio-based epoxides and first paper to give an overview of fungal and bacterial oils for such application.

The yeast Phaffia rhodozyma is widely used as a natural source of astaxanthin for aquaculture, but its protein-rich biomass has been less studied as single-cell protein (SCP). This study explored the potential of P. rhodozyma as a dual-purpose production system by optimizing a low-cost medium for a protein-enriched mutant (AEC3/9), while also monitoring astaxanthin formation. A central composite design and response surface methodology (RSM) were used to evaluate the effects of glycerol, urea, ammonium sulphate, and initial pH. Shakeflask cultivations performed in triplicate (250 mL baffled flasks, 20 mL working volume, 22 °C, 250 rpm, 7 days) showed that protein productivity reached its maximum on day 4, which was selected as the reference point for optimization. Astaxanthin was included in the model but was not used as the main optimization target. The optimization results suggested that moderate glycerol concentrations (70–90 g/L), low urea (<0.2 g/L), and slightly acidic pH (5.9) were the most suitable conditions. Under the selected conditions (70.54 g/L glycerol, 0.134 g/L urea, 4.98 g/L (NH₄)₂SO₄, pH 5.86), biomass reached 26.11 g/L with a protein content of 29.79 % (7.78 g/L). Scale-up in a 5 L stirred-tank bioreactor confirmed the feasibility of the process, reaching 33.50 g/L biomass and 6.82 g/L protein at 88 h. The results indicate that protein accumulation occurs before the phase associated with increased astaxanthin production. Optimizing nitrogen source and pH allows stable production of P. rhodozyma biomass on glycerol, supporting its use as an SCP co-product alongside astaxanthin.