Soul Chun

Comparing Primary Energy Attributed to Renewable Energy with Primary Energy Equivalent to Determine Carbon Abatement in a National Context

The current conventional approach to determining the primary energy associated with non-combustible renewable energy (RE) sources such as wind energy and hydro power is to equate the electricity generated from these sources with the primary energy supply. This paper compares this with an approach that was formerly used by the IEA, in which the primary energy equivalent attributed to renewable energy was equated with the fossil fuel energy it displaces. Difficulties with implementing this approach in a meaningful way for international comparisons lead to most international organisations abandoning the primary energy equivalent methodology. It has recently re-emerged in prominence however, as efforts grow to develop baseline procedures for quantifying the greenhouse gas (GHG) emissions avoided by renewable energy within the context of the Kyoto Protocol credit trading mechanisms. This paper discusses the primary energy equivalent approach and in particular the distinctions between displacing fossil fuel energy in existing plant or in new plant. The approach is then extended provide insight into future primary energy displacement by renewable energy and to quantify the amount of CO2 emissions avoided by renewable energy. The usefulness of this approach in quantifying the benefits of renewable energy is also discussed in an energy policy context, with regard to increasing security of energy supply as well as reducing energy-related GHG (and other) emissions. The approach is applied in a national context and Ireland is case study country selected for this research. The choice of Ireland is interesting in two respects. The first relates to the high proportion of electricity only fossil fuel plants in Ireland resulting in a significant variation between primary energy and primary energy equivalent. The second concerns Irelands poor performance to date in limiting GHG emissions in line with its Kyoto target and points to the need for techniques to quantify the potential contribution of renewable energy in achieving the target set.

Using Organic Matter with Chemical Amendments to Improve Calcareous Sodic Soil

Abstract Kangping soil in northeast China is a sodic soil characterized by a high pH and excessive sodium. The high pH and excessive sodium in sodic soils generally cause loss of soil structure, reduce hydraulic conductivity (HC), increase soil hardness, and make the soil unproductive land. After we mixed organic matter (rice straw) and chemical amendments (H2SO4, CaSO4, and FeSO4), a column experiment was conducted to evaluate the physical and chemical properties of the soil influenced by the changes in HC, penetrability of soil s`urface, pH, electrical conductivity, CO3 2‐, HCO3 −, Ca2+, Na+, sodium adsorption rate (SAR), available phosphorus (P) and iron (Fe), and leached P. Organic matter decreased the concentrations of CO3 2‐, HCO3 −, and Na+ in soil solution and increased the total volume of the leachate. Organic matter also reduced the amount of available Fe and increased the available P. However, organic matter did not affect the penetrability of the soil surface as much as soil hardness, HC, and SAR within the short period of this experiment. Among the chemical amendments, H2SO4 and FeSO4 were more effective than CaSO4 to restore HC, electrical conductivity, Na+, and SAR. The chemical amendments, compared with organic matter, significantly leached P from the soil in this study, but the leaching was independent of the concentration of available P in the soil. The CaSO4 had the strongest effect in increasing leached P from the soil without changing the concentration of available P in the soil. Organic matter with added CaSO4 leached P from the soil more than all other treatments.

Response of Corn Growth in Salt‐Affected Soils of Northeast China to Flue‐Gas Desulfurization By‐product

Abstract In semiarid and arid regions, plant growth is limited by high pH, salinity, and poor physical properties of salt‐affected soils. A field experiment was conducted in the semiarid region of Kangping in northeast China (42°70′ N, 123°50′ E) to evaluate a soil‐management system that utilized a by‐product of flue‐gas desulfurization (FGD). Soil was treated with 23,100 kg ha−1 of the by‐product. Results of corn growth were grouped into three grades (GD) according to stages of corn growth: GD1, seeds did not germinate; GD2, seeds germinated but corn was not harvested; and GD3, plants grew well and corn was harvested. The pH, electrical conductivity (EC), bicarbonate (HCO3 −), carbonate (CO3 2−), exchangeable and soluble calcium (Ca2+), chloride (Cl), and sulfate (SO4 2−) in surface soils of the three grades (>20 cm) was measured to assess the correlation between corn growth and soil properties. Vertical differences in subsoil properties (0‐100 cm) between GD1 and GD3 were compared to known benchmark soil profiles. The FGD by‐product significantly increased EC, exchangeable and soluble Ca2+, and SO4 2− and decreased CO3 2−, exchangeable sodium (Na+), and soluble Na+. pH, EC, HCO3 −, CO3 2−, and Cl− were higher in surface soils of GD1 than GD3. Soil hardness, soil moisture content, Cl−, and calcium carbonate (CaCO3) were higher in GD1 than in GD3, whereas the amount of available P was lower in GD1. Interestingly, the concentration of Cl−, a toxic element for plant growth, was 2.5 and 1.5 times higher in GD1 than in GD3 and control soil, respectively. In the comparison study of subsoils, GD1 and GD3 were classified as having typical characteristics of saline‐alkali soil (pH>8.5; exchangeable‐sodium‐percentage [ESP]>15; EC>4.0) and alkali soil (pH>8.5; ESP>15; EC<4.0), respectively.

SELECTION PROCEDURE FOR TURFGRASS IN NEW INCHEON INTERNATIONAL AIRPORT

The back-filled soil of the New Incheon International Airport in South Korea construction site was reclaimed with sea sand from the bottom of the sea and with sludge from along the bank of an inlet near Yongjong Island. The objective of this study was to investigate soil change to improve the soil properties where plant growth was limited by salts. The experiment was carried out from August 1993 to June 1997 to restore soil bases (SL, a base constructed using dredged sludge along the bank of an inlet; SD, a base constructed using dredged sea sand at the bottom of the sea; SDC, a base constructed using dredged sea sand at the bottom of the sea with 2 ton ha−1 calcium hydroxide; SDCD, a based constructed using dredged sea sand at the bottom of the sea with 2 ton ha−1 calcium hydroxide and with an established closed drainage system at 30 cm depth) and to select salt tolerance turfgrass species (Puccinella distans; Zoysia sinica; Zoysia japonica; CSG I, a combination of cool season grasses I with Festuca arundinacea 50% + Lolium perenne 30% + Agrotis alba 20% by weight; CSG II, a combination of cool season grasses II with Festuca arundinacea 50% + Festuca rubra 50% by weight) for a low maintenance area that included most of the open space of the airport site. In our study, soil salinity did not significantly affect the growth of turfgrass without irrigation in the dry season over the five years. The salinity decreased under 1 dS m−1 in 70 days on bases SD, SDC, and SDCD only with rainfall. Zoysia sinica and Zoysia japonica had a higher turfgrass coverage than Puccinella distans, CSG I and CSG II.