Assessment of Peat Deposits in Rwanda

The peat deposits in Rwanda are distributed over an area of 50,000 ha and were formed about the end of last glaciations period. However Akanyaru peat is 20,000 years old and contains peat of glacial and postglacial period. The studies show that Rwanda has 155 million tons of dry peat which can generate electrical energy and this deposit is sufficient to meet country’s vast energy requirements for 30 years. Hence, it was felt necessary to map prospective locations of peat and their energy potential. The result of the study and assessment of peat to power in Rwanda show that the average in-situ ash content, in-situ moisture content and in-situ bulk density of the collected peat samples are 36 wt%, 70.8 wt% and 1112 kg/m3 respectively. Their average thickness ranges from 0.9 to 7.8 m. In Finland, peat was used as fuel in 1996 and produced 10% of total installed capacity. Rwanda has the same operational peat power plant in Gishoma: Rusizi District generating 15 MW connected to the national electrical grid. A peat-fuelled power plant is under construction and is expected to generate 80 MW. This plant, once completed, is expected to connect 50% more households into national grid. Thus, this effort along with other projects will increase electrical power from 208 MW to 563 MW in 2024. Peat deposit is expected to generate 500 Megawatt electrical powers for 30 years. Although an effort was done to use peat as fuel, the power plant is still vulnerable to the lack of good quality of dry peat to operate and thus efforts are on to develop suitable technology for exploitation.

Habitat Influence on the Molecular, Carbon and Hydrogen Isotope Compositions of Leaf Wax n-Alkanes in a Subalpine Basin, Central China

Epidermal leaf waxes of terrestrial higher plants have been widely utilized for the reconstructions of paleoenvironment and paleoclimate in peat deposits. In this study, specimens of four plant species growing in both peatland and non-peatland habitats were retrieved to compare their molecular, carbon(δ13 C) and hydrogen(δ2 H) isotopic compositions of leaf wax n-alkanes from a closed subalpine basin in Central China. Three of the four species show quite higher total concentrations of n-alkanes in the relatively dry non-peatland setting than in the peatland. In addition, the δ2 H values of long-chain n-alkanes are generally less depleted in the peatland and are comparable among different plant species, which is interpreted as the influence of inundation condition and the possible limited supply of photosynthetic products. This study reveals different patterns of plant wax molecular and isotopic compositions between peatland and the surrounding non-peatland conditions, and confirms the paleoenvironmental potential of leaf wax ratios on the peat sequences.