Energy recovery from waste biomass can have significant impacts on the most pressing development challenges of rural poverty and environmental damages. In this paper, a techno-economic analysis is carried out for electricity generation by using timber and wood waste (T & WW) gasification in Iceland. Different expenses were considered, like capital, installation, engineering, operation and maintenance costs and the interest rate of the investment. Regarding to revenues, they come from of the electricity sale and the fee paid by the Icelandic municipalities for waste collection and disposal. The economic feasibility was conducted based on the economic indicators of net present value (NPV) and discounted payback period (DPP), bringing together three different subgroups based on gasifier capacities, subgroup a: 50 kW, subgroup b: 100 kW and subgroup c: 200 kW. The results show that total cost increases as the implemented power is increased. This indicator varies from 1228.6 k�for subgroups a to 1334.7 k� for subgroups b and 1479.5 k�for subgroups c. It is worth mentioning that NPV is positive for three subgroups and it grows as gasifier scale is extended. NPV is about 122 k�(111,020 $), 1824 k�(1,659,840 $) and 4392 k�(3,996,720 $) for subgroups a, b and c, respectively. Moreover, DPP has an inversely proportional to the installed capacity. It is around 5.5 years (subgroups a), 9.5 months (subgroups b) and 6 months (subgroups c). The obtained results confirm that using small scale waste biomass gasification integrated with power generation could be techno-economically feasible for remote area in Iceland.
The rapid development of global economy, increasing population and living standards has been posing great pressure on energy resources and the environment. There is an urgency to use local renewable energies to promote local development and also reduce carbon emission. Waste biomass is an abundant and renewable energy that creates low net CO2 emission. It is also the only suitable and primary energy resource that can provide transportation fuels [
Beneficially, waste biomass gasification can be applied for small/medium scales that lead to dramatic reduction of some pollutants emission as furans, dioxins, and NOx and the possibility of the utilization of the syngas in high efficiency thermal devices like internal combustion engine and gas turbines [
In this paper, we will explore the potential of timber and wood waste (T & WW) gasification for energy production in small communities in Iceland, (T & WW is the most existing biomass feedstock in this country). In this way, a techno-economic analysis of T & WW gasification facilities integrated with electricity generation unit will be directed for three subgroups with different gasifier installed power, 1): 50 kW, 2): 100 kW and 3): 200 kW to propose a sustainable waste to power system adapted with conditions in Iceland.
T & WW is transferred from the waste fields to pre-processing part that is next to gasification and electricity generation unit. Diesel fuel is used in trucks
| Parameters | Value (%) |
|---|---|
| Proximate analysis (wt%) | |
| Moisture | 5.01 |
| Volatile matter (VM) | 93.06 |
| Fixed carbon (FC) | 6.38 |
| Ash | 0.56 |
| Ultimate analysis (wt%-dry basis) | |
| C | 56.8 |
| H | 7.28 |
| N | 0.18 |
| Cl | 0.82 |
| S | 0.07 |
| O | 34.29 |
for transportation and electricity is applied for driving force and heat generation over the process. The electricity production in Iceland is derived from geothermal and hydropower that makes Iceland’s main source of clean energy. The gasification process consists of drying, pyrolysis, combustion and gasification [
In the economic assessment, all prices are expressed in K?(kilo-euro) and the interest rate is 8%. A computer program has been developed to investigate economically for three subgroups of 50 kW, 100 kW and 200 kW of gasifier installed power. The model is able to evaluate the cash flow analysis, total cost, Net Present Value (NPV) and Discounted Payback Period (DPP). A project is an economically attractive while it has the lowest DPP and the NPV higher than zero. NPV is calculated based on Equation (1) [
N P V = ∑ n = 1 t C F n ( 1 + r ) n − C c (1)
where C F n is the annual cash flow, being the difference between Revenues (R) and Expenditures (E), Operation and Maintenance Costs (CO&M), r is the discount rate, Cc is the total capital costs of investment and t is the lifetime of the investment (15 years). DPP is calculated according to Equation (2):
D P P = L N ( 1 1 − C c × r C F ) L N ( 1 + r ) (2)
The periodic cash flow, with all the revenues and expenditures, is calculated by considering the incomes from the generated electricity, and the credits for the Waste Treatment Bill (WTB) [
The whole yearly CO&M can be determined by the sum of the costs for the maintenance cost (2% of Cc), insurance and tax (2% of Cc), waste disposal (15% of Cc), electricity cost, liquid fuel cost and personnel cost. Electricity costs are calculated based on electricity consumers and liquid fuel costs are estimated for fuel consumers with 7000 hr/year of plant availability [
In relation to revenues, the selling price of electricity to normal households and small businesses in Iceland is about 124.69 $/MWh [
The total cost of the generation plant for each subgroup is shown in
O & M costs in total cost. The yearly O & M costs occupies more than 55% of total cost for the first subgroup, it has also the dominant statue among different kinds of costs for subgroups b (43%). However, the highest share is related to gasification system price for subgroups c.
The economic assessments, based on the indexes of NPV and DPP for three subgroups, are shown in
In this work, techno-economic of power production plant that utilized syngas from a timber and wood waste gasification process in Iceland was investigated. The technical assessment focused mainly on input waste, and installed power. The economic assessment was conducted relied on the economic indicators of total cost, revenues, NPV and DPP, for three subgroups with different gasifier installed power, 1): 50 kW, 2): 100 kW and 3): 200 kW. The results show that total cost increases as the implemented power is increased. This indicator varies from 1228.6 k?for subgroups a to 1334.7 k?for subgroups b and 1479.5 k?for subgroups c. It should be emphasized that NPV is positive for three subgroups and it grows as gasifier scale is extended. The NPV in subgroup c, is averagely 58% and 97% higher than subgroups b and a, respectively. NPV is about 122 k? 1824 k?and 4392 k?for subgroups a, b and c, respectively. Moreover, DPP has an inversely proportional to the installed capacity. It is around 5.5 years (subgroups a), 9.5 months (subgroups b) and 6 months (subgroups c). Finally, the obtained results confirm that using small scale waste biomass gasification integrated with power generation could be techno-economically feasible for remote area in Iceland.
This paper was a part of the project funded by Icelandic Research Fund (IRF), (in Icelandic: Rannsoknasjodur) and the grant number is 196458-051.
The authors declare no conflicts of interest regarding the publication of this paper.
Safarian, S., Unnthorsson, R. and Richter, C. (2020) Techno-Economic Analysis of Power Production by Using Waste Biomass Gasification. Journal of Power and Energy Engineering, 8, 1-8. https://doi.org/10.4236/jpee.2020.86001